HK1076973B - Multiple mode personal wireless communications system - Google Patents

Description

Multi-mode personal wireless communication system

Technical Field

The present invention relates to an improved wireless communication system. More particularly, the preferred embodiment of the present invention relates to a multi-mode communication system that includes a special handset designed to operate in a standard analog or digital protocol when it is within the coverage area of a standard cellular radiotelephone network, and to operate in a special protocol when it is within the coverage area provided by an independent, low-power "pico" cell connected to the radiotelephone network. The term "pico" as used herein refers to a smaller size than the cell of a conventional cellular radiotelephone. The picocell placement at a user-selected location cooperates with the structure of the overlay cell that operates independently of the cells of the cellular network.

This overlay cellular architecture allows the service provider complete control of each particular handset and picocellular system through the service control unit and host station. The standard cellular system can also be enhanced by the addition of zone identifier overhead information which is ignored by standard handsets but interpreted by special handsets to continuously inform those users of the current mode of operation of the special handset.

Background

There has long been recognized a need for ubiquitous communication services that assign each user a personal service number and provide suitable equipment to allow the user two-way communication capability (i.e., the ability to make and receive calls) despite changes in the location of the user.

To achieve this capability more quickly from a technical standpoint, systems have been developed that extend the traditional wireline telephone service. For example, recent innovations in paging, standard cordless in home telephone service, cellular telephone service, and personal communication systems are well known. The design of such systems all include efforts to effectively meet the needs of the ultimate pervasive business. However, each system has well-recognized technical deficiencies that make it incapable of providing widespread telecommunications services.

For example, conventional systems control the operation of remote devices through remote programming. However, such conventional systems require original programming to establish a telephone system identification, such as a Mobile Identification Number (MIN), which may be used in future calls to provide remote programming. This is a poor remote programming technique because it does not allow the original programming to be done remotely. As a result, a complete complex and expensive infrastructure is provided to handle the original programming of the remote device by physically accessing the device.

In addition, conventional cellular systems monitor the power level of the transmitted signal to determine if the signal level is high enough to warrant the provision of communication service. Such conventional systems have relatively low access thresholds because they are reluctant to relinquish communication traffic to any potential user and to relinquish revenue that may be obtained thereby. However, conventional cellular systems may switch or drop immediately after receiving a weak signal access from a handset. This is a poor technique when applied to serving cells that do not support handover or where it is desirable to minimize handover overhead communications, as it results in calls being dropped or handed over immediately upon access.

In addition, conventional cellular systems are designed such that users do not know when their calls are about to be dropped by the serving cell. When a call is dropped by a serving cell, it is desirable for another cell to be able to accept the call through a handover procedure. However, in conventional and other cellular systems, the availability of another serving cell is not guaranteed. This is a poor operating technique because the user is not alerted to drop the call in the event that the user may be able to take steps to avoid the call being dropped.

In addition, when conventional systems provide, for example, call waiting tones and other alerting signals during a call, such alerting signals are often set to be known by both parties to the call. This is also a poor operating technique. A party that is not alerted during a call typically does not need to know the alert. When this party knows this warning that is not meaningful to him or her, the result is often confusing and a session flow is often unnecessarily disrupted.

Also, conventional systems are designed to provide services through a handset only if they are able to do so. They are generally unaware that multiple communication services may be implemented by multiple different communication systems, such as multi-cellular systems and landline services. They also fail to integrate multiple services into a common handset and provide the user with meaningful information about the different communication service options that handsets often have.

Accordingly, there remains a need for an improved communication system that provides users with communication services that are more nearly universal than existing systems.

Disclosure of Invention

It is therefore an object of the present invention to provide an improved telecommunications system which more fully satisfies the user's need for low cost, ubiquitous communication services.

It is a further object of the present invention to provide an improved telecommunications system designed to include a standard cellular network and also a network covering cells operating independently of the cells of the cellular network.

It is a further object of this invention to provide a multi-channel pico station at each subscriber location in such a system, which in turn supports a plurality of portable telephone handsets, each handset being capable of operating in either a wireless or pico mode when it is in the subscriber premises and a standard cellular mode when it is away from the subscriber premises and yet within the cellular coverage area.

It is a further object of this invention to provide such an improved telecommunications system wherein call forwarding capability is provided by unique ringing assistance so that a user carrying a portable personal handset selectively operating in one of the dual modes can receive and quickly identify incoming calls directed to an assigned cellular subscriber number through the unselected or inactive system mode.

It is a further object of this invention to provide such a dual mode portable handset with automatic registration and control without user intervention and to provide the user with a display that at any time informs the user of the operational state or mode of the handset settings so that the user can make an educated, cost effective decision on the placement of a call.

It is another object of the present invention to provide a mode of operation in a dual-mode system using one radio per handset based on a specific, but cellular compatible, protocol that allows dynamic channel allocation and occupancy.

It is another object of the present invention to provide an alternative line selection capability that allows call traffic to be selectively distributed between the subscriber premises and the cellular network.

Accordingly, the present invention provides an RF link module for providing wireless communication services to a consumer telephone device connected to the RF link module through a consumer premises line, the RF link module comprising: a processor unit used for automatically deciding whether to program an identification number into the RF link module; a radio frequency transmitter and receiver coupled to the processor unit and configured with the processor unit to obtain programming parameters from a remote programming system via wireless communication when the identification number is not programmed, the programming parameters configured as an identification number; and a telephone line interface module connected to the radio frequency transmitter and receiver.

Accordingly, the present invention provides an alternative line selection ALO module for providing wireless telephone service to a consumer telephone device connected to said ALO module by a consumer premises line, said ALO module comprising: a processor unit for deciding whether a mobile identification number MIN is programmed into the ALO module; a radio frequency transmitter and receiver coupled to the processor unit and configured with the processor unit to obtain activation parameters from a remote programming system via wireless communication when the MIN is not programmed, the activation parameters including the MIN; a telephone line interface module; a ring voltage generator coupled to the processor unit and the telephone line interface module and configured with the processor unit to provide a ring signal to the consumer telephone device over the line in response to detecting an incoming call for the MIN; a telephone line interface module coupled to the processor unit and the telephone line interface module and configured to provide a predetermined DC voltage to the consumer telephone device over the telephone line; and a dial tone generator coupled to the processor unit and the telephone line interface module and configured by the processor unit to provide a dial tone to the consumer telephone device over the line when the consumer telephone device is off-hook; wherein the processor unit is further configured to capture a first digit dialed at the consumer telephone device, and to clear the dial tone in response to capturing the first dialed digit, then capture a full telephone number dialed at the consumer telephone device, and initiate a wireless telephone using the captured telephone number.

The present invention also provides an alternate line selection module for installation between a consumer's two-wire telephone connection and a wired public switched telephone network PSTN, comprising: switching means connected between said consumer two-wire telephone connection and said wired PSTN for selectively interrupting said two-wire connection to disconnect said consumer connection from said wired PSTN; control means connected to said switching means for providing call assignment messages to said switching means for selectively assigning communication services between said PSTN and the wireless telecommunications network, said control means including an intelligent processor responsive to control messages from a wireless carrier over a wireless communication link, said control messages being received prior to communication of said call; and means, responsive to said switching means, for activating a wireless network transceiver in said module to provide said call communication service using said wireless network.

These objects and other features and advantages of the present invention are obtained in a telecommunications system designed to operate in conjunction with a standard cellular network having a plurality of serving cells of either analog or digital configuration and standard geographic coverage. The system also includes a network of overlay cells that operate substantially independently of the standard cells of the cellular network. In addition, the system may be used in wireless telephone networks having other features, such as SMR networks.

Preferably, each coverage cell provides wireless communication coverage over a geographic area generally corresponding to a cell site area, but in order not to cause interference, the wireless communication coverage is over a set of selected reserved cell frequencies that are as far apart as possible from the assigned cellular network signal frequency.

For cooperation with the overlay serving cell, a base station, referred to herein as a pico station, is placed at each user location. Each pico station is designed to support up to 6 improved portable handsets operating in dual mode. In the first mode, each handset operates as a normal portable network or cellular telephone when the handset is physically removed from the vicinity of the pico station. The second wireless mode of operation of the system handset described herein is referred to herein for the first time as enhanced cordless and will be referred to in subsequent use as pico mode. The enhanced cordless mode of the present invention differs from the operation of a standard cordless telephone in several respects. This system uses a unique burst mode communication control protocol between the handset and the pico station that is not seen in standard cordless operation. This protocol is compatible with cellular standards to allow multi-mode operation not possible with standard cordless. Furthermore, the standard cordless frequency allocation is clearly different from the cellular frequencies used in this system. Other differences will become apparent as the description proceeds, with the result that there is an operational improvement in the services provided.

The unique protocol used by this system allows for remote activation and control using the 10k bit manchester encoded data channel inherent in the cellular phone hardware. Thus, when close to the pico station, the handset operates as a cordless telephone supported by the pico station via the PSTN line connected to the house.

In the preferred mode, the transmission of the call is provided over a link that may include a two-way line selection module connected between the pico station and the PSTN. By that arrangement, traffic may be provided through direct access from the pico station to the public switched telephone network, or traffic from the pico station may be selectively redirected back to the cellular network through the radio of the two-line selection module. An important advantage of this system comes from the ability to distribute selected portions of the call traffic between these two paths to accommodate call capacity and to change call requirements. This allows the system to be used in areas with limited cellular capacity without having to force the traffic to be dosed.

The service control unit and host station are used to help build and control portable handsets and pico stations using remote programming techniques that were previously impractical.

Each handset includes similar components to a standard analog cellular telephone having a wireless transceiver. In addition, the handset has additional software to allow it to operate in pico mode in cooperation with a pico station located at the user's premises. As an alternative to analog technology, the improved handset may appear to be compatible with digital technology, and the same necessary additions or improvements to the pico station may be made.

After initial setup, each handset uses a process to identify when it is in the vicinity of its authorized pico station. The handset will then find its authorized pico station by periodically transmitting a signal to determine if it is within an acceptable communication range. If the pico station receives an acceptable handset signal level, it responds and exchanges registration information with the handset to set up or register the handset in pico mode.

The handset then transmits a message to the cellular system on which it is still operating, instructing all subsequent attempted incoming calls on the cellular network to be forwarded to the authorized pico station number (which may be the subscriber's home PSTN number). Finally, the handset switches to pico mode and transmits an acknowledgement control message to the pico station indicating that it is "home" and in service. At that time, a message is displayed on the handset indicating that the user's handset is in pico mode as opposed to cellular mode.

While in pico mode, the system operates on selected, reserved cellular channels at a low power level using the same basic technology standard as an analog AMPS-type cellular system. During this mode, the pico station can and must operate as a telecommunication base station without handover capability.

Up to six handsets may be registered with the pico station. In the preferred embodiment only one handset can transmit at a time. However, the system supports the ability of other handsets to join the ongoing call. During call activity, the handset-to-pico station link is established at a very low power level, which results in low battery consumption.

The pico station is directly connected to the home telephone line from which the call is sent, but is always controlled by the service control unit and the overlay host station located in the network area via a radio frequency link. When the handset is carried out of range of the pico station while in operation, it automatically switches back to cellular mode and cancels all existing call forwarding.

It should be noted that the operation of the particular handset and overlay network of the present invention is transparent and will not interfere with standard cellular network operation.

Drawings

FIG. 1 is a system block diagram of a preferred embodiment of the system of the present invention;

FIG. 2 is a component diagram of a handset for use with the system of the present invention;

FIG. 3 is a system handset diagram illustrating keypad layout and other external features;

FIG. 4 is a component diagram of a pico station of the system;

FIG. 5 is a diagram of a service control unit configuration of the system;

FIG. 6 is a component diagram of a two-alternative line selection module for use in the system of the present invention;

FIG. 7 is a flow chart of the operation of a pico station in set up and activation operations;

FIG. 8 is a flow chart of operation of a pico station in a pico station configuration operation;

FIG. 9 is a flow chart of the operation of a pico station in a handset authorization operation;

FIG. 10 is a flow chart of the operation of a pico station in a scan channel operation;

figure 11 is a flow chart of the operation of a pico station in call and idle loop operation;

FIG. 12 is a flow chart of the operation of a pico station at call origination and call connection operations;

figure 13 is a flow chart of the operation of a pico station at call termination operation;

FIG. 14 is a flow chart of handset operation during initialization and traffic determination operations;

figure 15 is a flow diagram of handset operation when monitoring pico stations and finding channel operation;

FIG. 16 is a flow chart of operation of the handset when authorizing operation of the handset;

fig. 17 is a flowchart of the operation of the handset in the registration operation of the handset;

FIG. 18 is a flow chart of the operation of the handset in reacquiring operation of the pico station;

FIG. 19 is a flow diagram of handset operation when handset cellular idle, speed dial, and cellular session operations;

fig. 20 is a flowchart of the operation of the handset in the case of a dial input operation;

FIG. 21 is a flow chart of operation of the handset in both numeric input and non-numeric input operations;

FIG. 22 is a flow chart of operation of the handset during operation of the other parts of call selection and transmission;

FIG. 23 is a flow chart of handset operation when operating in conjunction with a pico station;

fig. 24 is a flowchart of the operation of the handset in processing base station command operations;

FIG. 25 is a flowchart of the operation of the two-alternative line selection module during initialization, configuration, and traffic determination operations;

FIG. 26 is a flow chart of operation of the two-alternative line selection module during call processing operations;

FIG. 27 is a diagram of handset message format bit allocation for system component reverse control channel communications operating in pico mode;

FIG. 28 is a diagram of pico station message format bit allocation for system element forward control channel overhead and registration command words operating in pico mode;

FIG. 29 is a diagram of pico station message format bit allocation for system components operating in pico mode forward control channel call processing commands and grant command words;

FIG. 30 is a framing diagram of forward and reverse channel communication packets of the system;

FIG. 31 is a diagram of a traffic control unit message format bit allocation for reverse control channel setup and control command words communicated to pico stations on an overlay network;

FIG. 32 is a flowchart showing a call connection procedure performed by a pico station;

fig. 33 shows a flow chart of normal session operation performed by the handset.

Detailed Description

Overview of the System

The system of the present invention comprises a combination of components, one at the home, or at another customer site, and which results in an economical, convenient telecommunications service when the customer leaves the home site.

From a service provider's perspective, the system of the present invention is designed to provide a particular service to a selected group of subscribers, and also to cooperate with and operate within a standard wireless telephone network, such as a cellular network that supports both analog and digital configurations of conventional cellular subscribers. In addition, the system typically includes a network of overlay cells that generally correspond to the cell locations in a cellular standard network. The overlay serving cell network provides wireless communication coverage over a geographic area generally corresponding to the cell site area, but in order not to cause interference, the wireless communication coverage is over a selected set of reserved cellular frequencies that are as far apart as possible from the assigned cellular network signal frequencies. The pico stations at each selected user site interact with suitably distributed overlay serving cells. The pico station receives calls from special handsets and transmits the calls to the PSTN over the house wires. In this approach, the system can support wireless or pico mode operation for a selected group of users in addition to providing services on a standard network, while they are at home or at a service site.

The improved wireless communication system is capable of supporting multiple, dual-mode telephone handsets associated with each pico station, each handset capable of operating in pico mode when they are in the subscriber's premises; and are able to operate in standard and cellular modes when they are located outside the user's premises and still within the standard or cellular network coverage area. The advantage of this system is that it is able to handle significantly increased call traffic as it allows for efficient use of all the equipment of the system.

A pico station is a dynamic spectrum, non-acquisition, network-transparent personal picocell within a network.

System component

Referring now to the drawings and in particular to FIG. 1, a preferred embodiment of the invention will be described. Figure 1 shows one of many cellular switches or cells 10a of an existing cellular system. The cell may be configured for standard operation with either AMPS, or TDMA or CDMA digital services of conventional design. EIA or TIA standard 553 defines mobile station and ground station compatibility specifications for cellular systems, to which all licensed cellular operations in the united states comply. The system of the present invention is intended to adhere to or be compatible with these standards.

The illustrated cell site may also be the physical location of the covering cell and antenna 10b that provides wireless coverage over a geographic area generally consistent with the cell site.

However, the coverage cells operate on a selected set of reserved frequencies that are appropriately spaced from the cellular frequencies of interest so that they do not interfere with cellular radio operation. At least one channel is reserved for commands only and other reserved channels can provide call and command capabilities. In this regard, it should also be noted that all communications from the handset to the pico station are on the reserved call channel, except for authorized communications, whereas the traffic control unit to pico station communications are primarily only on the command channel.

The standard cellular frequency allocation is specified in section 2.1.1.1 of EIA-553. In the preferred embodiment, the selected reserved common control channel for use by the B-side is 799, which is the channel furthest from the B-side signal allocation. The call channel reserved by the B-side will typically be channel 798-789.

For use on the a-side, the reserved common control channel is selected 991 with the largest separation from the a-side signal allocation. The call channel reserved on side a will typically be channel 992-. Obviously, a small number or additional channels should be reserved, with six to twelve channels being a preferred range.

In addition, an array of geographically distributed, separate coverage cells should be used, enabling radio coverage substantially comparable to the geographic area of the associated cellular network, as compared to the cellular cells.

The pico station 26 is located at the subscriber location and is interconnected to the PSTN by a cable through a standard RJ11 interface to an existing house telephone line. In the illustrated embodiment, two-alternative line selection module 22 is connected between the pico station and PSTN 20 by cable 24. The two-way line selection module is located at or near the subscriber location, which in this preferred embodiment may represent a residential premises or a commercial premises. Although not required, a standard wired telephone handset or handsets may be interconnected with the house wiring as shown, if desired. If desired, the two-way routing module may be omitted from the system or selectively used, with or without associated pico stations in the same premises. Thus, the alternative line selection module is a stand-alone device that can be used with any device that interfaces with house wiring.

Up to 6 dual mode portable handsets (32a-f) are provided, each associated with a pico station and capable of operating in dual mode, as will be explained in more detail below, under the control of the pico station and a service control unit.

In the first mode, each portable handset operates like a portable cellular telephone operating through a direct wireless connection to the serving cell 10 a. In the second mode, the handset operates as an enhanced cordless telephone supported by a pico station located at the subscriber's premises. In the latter or pico mode, calls may be routed via the pico station to the public switched telephone network over the connection to the home wireline telephone service, effectively using a combination of wireless and PSTN support. If a two-alternative line selection module is installed in the system, it also provides selective channel call capability to and from the handset over the indicated radio link through the pico station and the two-alternative line selection module, and through the cellular network represented by serving cell 10 a.

At least one service control unit 12 is provided for each overlay cell and is in contact with the system via a cable connection to the cell site, while a personal computer 16 is also in contact with the service control unit via a cable connection. The service control unit is connected via a PSTN and cable connection 14 to a host station 17 having a workstation 18. The host is also connected to a subscriber activation system 23 via a standard x.25 channel, as is commonly used by cellular carriers to control the activation and programming of cellular handsets allowed for use on a given cellular network. The remote programming functions of the host system are suitably implemented by a subsystem such as that described in U.S. patent No. 5,046,082, previously mentioned and incorporated herein by reference.

Referring now to fig. 3, a handset for use in the system is shown to include a housing 31, a keypad 32, an antenna 34, and a display 35. The keypad includes a standard twelve key section 38, a power switch 39, and a clear key 40. The usual "send" key is replaced by a green key 41 with a special label and the "end" key is also replaced by a red key 42 with a special label. When the green or off-hook key is pressed, a dial tone is provided and a call sequence is initiated. When the red or on-hook key 42 is pressed, the call sequence is terminated.

The handset differs from the standard cellular appearance design only in that the function keys 41, 42 differ in that the handset does not include a send key, the handset provides accurate dial tones by using a standard DTMF generator in the handset according to the flow control explained in connection with fig. 20. The dial tone is used in conjunction with the north american numbering plan function to detect completion of the dialing status. As a result, handset dialing schemes differ from standard cellular dialing in that the handset immediately generates a local dial tone when off-hook to indicate that subscriber service is active and a call can be placed. The dialing process then follows standard PSTN conventions (off-hook, dial tone, dial, call process, connect, talk and hang-up), which are familiar to telephone users.

The handset also has the ability to display to the user which mode of operation, pico or cellular, the handset is currently set in. This information is displayed on a standard LCD display 35 on the handset, along with other information (e.g., suitable information includes Wireless home # n, Local, and PREMIUM). The displayed status information enables the user to make informed decisions when placing and receiving calls, particularly when a particular service provider rate scheme is feasible.

Referring now to fig. 2, a block diagram of a handset similar to a conventional cellular handset is illustrated. The antenna 50 is connected to a duplexer 52 which in turn is connected to a receiver section 54 and a transmitter section 55. A speaker 56 is connected to the receiver and a microphone 57 is connected to the transmitter. The central processing unit 58 is interconnected with the receiver and transmitter by an input/output bus and an address/data bus. A display processor/keypad section 59 is also interconnected with the I/O bus in a conventional manner. The non-volatile memory EEprom 53 is also interconnected to the a/D bus in a conventional manner.

Each handset is assigned a unique Mobile Identification Number (MIN) that is used by the cellular system as the handset phone number. When the handset transitions from cellular system traffic to pico-mode traffic for a pico station, the handset automatically notifies the cellular system to forward all incoming calls to its MIN to the PSTN phone number associated with the instant pico station to which it is handed off. This process is reversed each time the handset transitions back to the cellular system service area and beyond the pico station or pico mode service area, as explained in the following description of the connection flow. The special functions of the handset are regulated by additional software executed by the central processor of the handset.

Referring now to fig. 4, there is illustrated a component diagram of a pico station including an antenna 60 coupled to a duplexer 62, which in turn is coupled to a receiver section 64 and a transmitter section 65. A central processor unit 66 of standard configuration is provided and a standard telephone line interface module 72 is connected to the receiver section and transmitter section by audio cables 68, 69 respectively. If desired, the interface module is also connected to a telephone line in the house, as illustrated in figure 1, which is connected to the two-alternative line selection module. The I/O bus interconnects the transmitter and receiver portions with the central processor, as does the address/data bus. A non-volatile EEprom 70 is also connected to the A/D bus. The status LED 73 and the authorization mode key 74 are connected to the I/O bus, respectively.

The purpose of the pico station is to provide an interface between each of its authorized handsets and the subscriber site PSTN telephone line or cellular system (if it is so configured). Each pico station is designed to support up to 6 handsets and each handset can be authorized for up to 3 pico stations to provide user adaptability. The pico station preferably operates in the cellular spectrum and always operates as a ground station during a pico mode communication session with the handset. However, unlike standard cellular ground stations, pico stations operate in pico mode and do not transmit a continuous stream of overhead data on a known channel to cause a handset to lock onto. Rather, the situation where the pico station and each handset locate and access each other using a unique burst mode communication operating protocol occurs only when communication is desired between those particular units. This results in an efficient system improvement since the channel is mainly used for call switching. In addition, the battery capacity of the mobile phone is saved.

This unique operating protocol is initiated by the initiating device (pico station or handset) after selecting a communication channel from a plurality of reserved channels. The channel selection process relies on the initiating device measuring the strength of any signal present on the selected channel and comparing this measurement to a predetermined acceptable value. If the signal present on the selected channel is less than the predetermined value, the channel is deemed to be available for the communication session. If the level is greater than the known value, the initiating device selects another channel from the plurality of known communication channels and performs the measurement and comparison process again until an acceptable channel is found. The selected channel is only occupied during the communication session and subsequently released. Once it is released, any nearby pico station or handset that avoids using this channel due to the presence of the measured signal can use this channel for the corresponding communication session and then release it in turn.

Both pico stations and handsets use very low transmit power. This fact, combined with the unique channel selection process and other advantages of the system, allows a relatively small number of channels to serve a very large number of user stations. Another benefit of dynamically selecting channels and using protocols is the elimination of the work currently used in standard cellular ground station systems that require pre-allocation of radio channels to adjacent picocell areas to avoid interference. This frequency-removal plan simplifies the use of the system, allows it to be successfully used in the neighborhood, and allows the public to quickly take advantage of the benefits provided by this system.

Activation and absolute control of the pico station is maintained by the cellular service provider through the use of a service control unit as illustrated in figure 5.

Referring now to fig. 5, which includes several of the components illustrated in fig. 1, they are labeled with the same numbers in fig. 5. Figure 5 additionally illustrates a mobile services control unit 80 useful with the fixed unit 12. Unit 80 comprises a vehicle having a personal computer interconnected to a cellular mobile radio unit 80b designed similar to a cellular telephone, and in particular, it also includes the software capabilities necessary to perform pico-mode overhead control operations in addition to the standard cellular overhead protocol.

In the illustrated embodiment, the mobile unit provides service control unit functionality for pico stations that may be out of range of the fixed service control unit; or the mobile unit may be used at the site of a fixed service control unit as indicated by numeral 12. When a mobile service control unit is used, it operates on a communication path from the host station 17 through the PSTN to the serving cell site 10 a. A communication path is then established between the serving cell site 10a and the unit 80 via a standard cellular radio link. To communicate with and control pico stations, unit 80 uses a radio link on a cellular frequency that is selected as a dedicated control channel, hereinafter referred to as a common setup and control channel. This wireless link conforms to a unique communication protocol that is compatible with the pico-mode protocol, which is a subset thereof, described in detail below. The message format of this protocol is specifically illustrated in fig. 31.

When using a fixed service control unit 12, a transmission link is used from the host station 17 through the PSTN to the service control unit. In addition, the service control unit is connected to the serving cell 10b of the system by a cable. Communication from the service control unit to the pico station is accomplished over the radio link from the serving cell 10b to the pico station using a dedicated control channel and the word operation protocol illustrated in figure 31.

It is clear that a fixed service control unit is a more suitable method of communicating with a pico station. However, at the beginning of system installation, there are gaps in the coverage network that may require the use of one or more mobile units. Alternatively, the mobile unit and the stationary unit may be used interchangeably or in the same general area. It should also be appreciated that when a mobile unit is used, it can rely entirely on transmissions from the host station or it can send information preloaded on the mobile unit via tape or other media loaded on a PC to a selected pico station. The same capabilities are possible for fixed service control units.

At a minimum, one of these devices needs to be placed in each serving cell site that serves the neighborhood in which the pico station is used. Each household in an urban or suburban area is exposed to cellular radio energy in a substantially ubiquitous cellular system coverage area. (most rural households are also within the service scope of a typical cellular provider and may be offered this service option). The service control unit uses this condition to use the reserved channel radio link between the serving cell 10b and the pico station to contact any pico station within its range to activate, update, audit and control its function and operation.

Like a handset in pico mode, the control unit also uses a unique operating protocol during its communication session with the pico station. These sessions always occur on a common control channel reserved for this purpose. The active session initiated by the traffic control unit remains intact on the common control channel. All other control unit sessions are initialized on any free channel of a plurality of channels known to the intended pico station and then immediately eventually move on to a common control channel. Any pico station can also initiate a session with the control unit by transmitting a request on the common control channel when it is idle.

The service control unit is linked to a centralized host station that maintains data records for all active pico stations and handsets within the service area of the cellular carrier. The host station is in turn linked to a central cellular client activation system (of the carrier) through which the host station receives data for each of the sold pico stations and handsets. This data is used by the host and to control the services provided during each pico station activation. The host computer station is also updated with changes to the user traffic profile by the client activation system. These updates are immediately communicated by the master station to the appropriate pico station via the control unit.

The components of the two-alternative line selection module are depicted in fig. 6. As shown, the PSTN is connected to a network interface device 83 via a cable 82. The network interface means is provided by a local switching carrier as demarcation means between the local switching carrier device and the premises wiring in the subscriber premises. Telephone line interface module 84 is connected to the output of the network interface device by cable 24. The connection to the house wires 86 is provided by a telephone line interface module through the cable 25.

The two-to-one line selection module includes a central processor unit 97 that controls all components of the two-to-one line selection via an input/output bus 99 and an address/data bus 98. The controlled components are the cellular receiver unit 88, the cellular transmitter unit 91, the talk battery replacement module 96, the 90vac ring voltage generator 95, the precision dial tone generator 94, the red/green status LED101, the remote programming modem 104, the real time clock 106, and the telephone line interface module 84.

The cellular receiver 88 and the transmitter 91 are connected to an antenna duplexer 93 by cables 89 and 92, respectively. Duplexer 93 is also connected to tethered antenna 100 by cable 105. Conductor 87 provides an audio path for audio received into the telephone line interface module. The transmit audio path passes through conductor 90.

The central processing unit 97 has an integrated microprocessor which also includes RAM for working registers, ROM for storing programs and EEprom for non-volatile data storage.

The two-alternative line option is typically powered by ac power source 102 but it also includes a battery backup 103 that can provide approximately one hour of continuous operation in the event of an ac power failure.

System protocol

The full coverage network and pico mode operating protocol of the system is implemented over a common air interface using the 10K bit manchester encoded data transmission method integrated in the cellular telephone. This implementation makes the hardware less expensive since processing 10kbit data messages is already a prerequisite for all cell stations. As a result, no additional hardware needs to be added to the handset to use this protocol.

The system message format is consistent with the standard cellular telephone format, but the message content is unique among the overlay network elements. Overlay network elements always use channels reserved specifically for them when communicating with each other. Thus, compatibility is provided between the existing cellular protocol and the protocols of the new system. In fact, the benefit of such an implementation is that any majority of existing cellular telephone manufacturers are able to support handsets simply by modifying their software that operates the handsets to support additional overlay network protocols.

In cellular mode, the base station behaves as a ground station and provides control over all transmissions of both the ground station and the handset. In pico mode, a unique protocol establishes a control relationship between the handset and the pico station for the first time. In particular, in the outbound call direction to the handset, the pico station is under the dominant control of the protocol. In terms of inbound calls, the handset is dominantly controlled per protocol.

In the traffic control unit-pico station relationship, the traffic control unit is the master and the link between those units includes a 10Kbit manchester encoded data stream. It should be seen that this is a reverse structure of control compared to existing cellular systems.

In the host-service control unit relationship, the host exerts a dominating control role and initializes messages based on service availability. As described in us patent No. 5,046,082, the communication connection between these units is according to a modem-based dial-up protocol using a unique DTMF scheme.

This direct application of the inventive technique with remote programming has been improved in the inventive system by eliminating the need for a data modem in the download operation of the link between the system control unit-the pico station. The need for a modem in a download operation pico station-handset link is also eliminated. This is accomplished by translating the unique DTMF modem access activation command sequence received by the service control unit from the host into a unique enhanced or pico protocol parameter information message format.

The same message format is then used in remote programming of the handset. As a result, the handset is again required to include an in-band modem. This reduction in hardware eliminates the limitations of existing applications in this system that do not facilitate remote programming of the handset. This makes remote programming of the handset cost effective.

In currently deployed systems, it is desirable that each member of the family has a cell phone that he or she personally uses. In a system configured as presently described, only a single call can be in progress at any one time. However, provisions have been made to interconnect more than one handset to a given call.

Other options are described below in connection with other embodiments. In addition, different ringing capabilities are described so that members of the family can easily distinguish between individual incoming calls.

Each handset attempts to operate in standard cellular mode when it leaves the pico station. The mode of operation of the handset uses the standard cellular overhead message protocol of the cellular system. When the handset is brought back within range of the pico station, it automatically switches to pico mode under the management of the pico station. The handset then operates on a unique control protocol supported by the pico station.

In view of these features, the system needs to include means for setting up and operating the handset in both modes. In addition, a unique conversion protocol is required to implement switching and automatic control of the handset between the two operating modes.

To describe all of the protocols required to operate the system of the present invention, fully described below, the steps necessary to enable a handset and a pico station to be used after the handset has been purchased by a user. The first step is typically to activate the pico station. The process for the handset includes an authorization process that is completed by the user and the cellular service provider after purchasing the pico station and the handset.

These activation and authorization processes include activation processing tasks typically necessary for a user to operate a handset in cellular mode, as well as special steps required to set up a handset and pico station for purchase for operation in pico mode. In addition, in order to be used with its associated pico station, the user must authorize each handset purchased. The handset will register automatically when within communication range of the pico station.

As a precursor to each handset's registration to the pico station, there is a cyclic process called location analysis, where each handset detects its cellular coverage area at its cellular site. This area also covers an authorized pico station thereof. This alerts the handset that it is near its home and is now within wireless range of the pico station authorized to operate. Only then will the handset attempt to contact its authorized pico station. This location analysis process is performed automatically each time the handset is used and is performed continuously if the location of the handset is changed by the user while the handset is cooperating with the cellular system. Its use in the system eliminates the inherent crosstalk or interference present in a number of other dual mode systems considered in the industry. In addition, location analysis conserves handset battery capacity and increases call traffic capacity of the reserved channel.

After successfully registering in the pico mode, the handset operates in a different state. The handset periodically performs reacquisition operations to maintain a registration relationship with the pico station. This procedure is activated by a timer and is another burst mode communication procedure designed to restrict the channel to use for non-conversational use, as explained in the flow of fig. 18. In the idle state, the handset may be generic. In addition, the handset can connect to a call process, can initiate a call process, and can terminate a call process through a specific process task flow described in detail below.

As explained previously, the pico station has not been activated for use by the user at the time of purchase. The activation process is performed "over the air" by a service control unit. The cellular bearer providing the pico-station service selects and reserves a single control channel for use by all service control units and pico-stations. This common control channel is known to the pico stations. Each pico station is also assigned a unique 22-bit Electronic Serial Number (ESN) by the manufacturer. The pico station ESN is captured by the customer activation system at the point of sale and transmitted to the selected host station according to the address and telephone number of the location where the pico station is intended to be used. The client activation system also transmits the MIN and ESN of each handset authorized to use the pico station to the primary station.

In response, the host station checks the pico station location address and selects the most appropriate service control unit to contact. The host station then issues a command to the selected service control units asking the target pico station to perform a positioning task.

Each associated service control unit then periodically sends out non-repudiatable access information on a common control channel, identified by the ESN, directed to the target pico station. This process is repeated until the target pico station is associated.

It should be appreciated that the non-repudiated access information ESN field may be additionally partially or fully encoded using different public-private key schemes. If used, this code provides a controlled access security capability for the cellular service provider, which can be used alone or in combination with the inherent security measures of the remote programming system access scheme to thereby create a dual level of security protection.

When the consumer installs the pico station at the desired location and connects its power supply, the pico station will immediately enter the initialization task in order to receive the non-repudiatable access information. The central processor of the pico station then performs internal housekeeping to place the pico station wireless and telephone lines in an idle state. The central processor of the pico station then uploads the contents of its EEprom to determine the operating status of the pico station. If the pico station is not configured, a pre-configuration task is entered. In that case, the central processor directs the pico station to wirelessly tune additionally to the known a-side, and the B-side control channel is used to check the contact with the service control unit.

Upon receiving the non-deniable access message addressed to its pico station ESN, the pico station transmits a communication setup message (ACK) at its full power to the service control unit. Upon receiving the ACK, the service control unit measures the signal strength of the received ACK signal of the pico station and transmits a terminate session command to the pico station. The service control unit then reports the results of its positioning task to the host station.

The master station, in turn, analyzes all results from the indicated traffic control units and selects one of the highest reported ACK signal strengths as the traffic control unit serving the pico station location.

This location confirmation procedure ensures to the cellular service provider that the address information provided by the subscriber is correct, such that each non-repudiation access message is directed to a specific portion of the total cellular system coverage. The master station then transmits all of the operating parameters that need to be forwarded to the selected pico station to the selected service control unit. This data is transmitted in the format of an activation command sequence.

Upon receiving the activation command sequence, the selected service control unit queues up a pico-station configuration session with the target pico-station. The service control unit begins the session by first transmitting a non-repudiation access message addressed to the target pico station. After receiving the corresponding pico-station ACK, the service control unit delivers a parameter information message defined in a parameter information message format described below to the pico-station.

The pico station receives each parameter information message and replies with an ACK message again. A non-acknowledgement (NAK) message from the pico station causes the traffic control unit to retransmit the parameter information message. When all messages are successfully transmitted, the control unit issues a terminate session command to the pico station. The service control unit then reports the successful activation process status of the pico station to the host station and saves a data file in its memory including parameters assigned to the pico station.

The consumer must also authorize each handset to use the pico station. This process is formulated to avoid unauthorized use of the pico station and the telephone line connected thereto. To begin this process, the handset must be powered up and "Base stationiuth" must be selected from the handset menu functions. The handset must then be brought into the vicinity of the pico station because the process is performed at a very low transmit level in order to avoid unintended access to any other pico station in the vicinity.

Thus, the pico station, upon receiving its configuration, enters a pre-authorization state and waits for its authorization button to be pressed, or otherwise contacted by the service control unit. The pico station changes the associated status LED from red to green.

The user then presses the authorization button on the pico station until the associated status LED flashes green indicating that the process has started. The handset display will also blink when an authorized session is in progress. In the process, the handset must remain close to the pico station for 3 to 7 seconds. The pico station uses a known common control channel for this grant process exchange.

During the authorization process, the pico station captures and verifies the MIN and ESN of the handset against the list of allowed handsets it receives from the service control unit. If a given handset is not on the list, the process it has designed fails without authorizing the handset. If a handset is expected, the pico station will communicate to it the listed parameter information using the parameter information message format described below.

The handset transmits an ACK message in response to each parameter information message it receives. If the handset NAKs a message, the pico station will retransmit that message. After all the messages are finished, the pico station sends a session termination command to the mobile phone to terminate the process. This returns the status LED of the pico station to a stable green state to indicate the termination of the process. The handset and pico station then return to their respective idle states.

Specific messages are identified in the flow descriptions of fig. 7-26. As previously indicated, these messages are all constructed using the words illustrated in fig. 27-31.

Fig. 27 depicts the general format of a particular data message word used by the handset in operation in the pico mode. The terms are expressed with reference to their actual positions in data messages transmitted by the handset to the pico station on the reverse channel of the occupied channel.

All the words depicted in the figures comply with the common format requirements of the EIA-553 standard-mobile station-ground station compatibility specification.

A handset data message may include one, two, or three words that are transmitted as packets on a reverse channel to convey communications to a pico station. The word position assignment for each entry in fig. 27 is always the word position of the particular data word assumed in the resulting data message as indicated by the word size. Each illustrated domain in the depicted word is identified by the standard designation of the domain specified by EIA-553.

To aid in understanding the message words of the description, some specific key fields are explained herein.

The NAWC field is the number of additional words and will reflect the total remaining word count in each transmitted message word. The command field, when included in a word, will always be set to 11110, indicating a local command without confusion with a network command. The ORDQ field is a command qualifier and is set to 000 except in the case where the best server and parameter information command is set to 001. The Local field, when included in a word, will include a 5-bit Local command pattern identifying the particular command being executed.

It should be seen that all of the figure 27 words only indicate pico stations and never cellular networks. Item 2701 is known as an abbreviated address word and is used as a single word command response message; the first word of each two-word access attempt message; and each three word identifies the first word of the command response message.

The access attempt message is used for authorization, registration, reacquisition, call origination, and call termination events. To aid in understanding and identifying the specific information included in each communication procedure, the messages referred to in fig. 27 are listed below. The authorized access attempt information includes 2701 (word 1) and 2702 (word 2) sent as a two-word message (I'll Take It). The initial registration access message includes 2701 (word 1) and 2703 (word 2) sent as two-word messages (Here I Am 1). The reacquisition access message from the handset includes 2701 (word 1) and 2704 (word 2) transmitted as a two-word message (Here I Am 2). The call origination access attempt generated by the handset prior to dial acquisition includes 2701 (word 1) and 2705 (word 2) sent as a two-word message (I wash In 1). The call origination access request message generated by the handset after dial acquisition includes 2701 (word 1) and 2706 (word 2) sent as the first two words of the message (I wash In 2). The handset call termination access attempt message includes 2701 (word 1) and 2702 (word 2) sent as a two word message (I'll TakeIt).

Item 2702 is referred to as a parameter message acknowledgement word and is always sent as a single word message to reply to the pico station during the authorization process to download the handset with the operating parameters required for pico mode operation. This single word acknowledgement message uses the bit positions 26 to 36 ACK or NAK for the parameter information message received from the pico station. Bit 26(X) is set to 0 to indicate ACK and to 1 to indicate NAK. Bits 27 and 28(AA) are set to 00 for the last command of ACK/NAK and to 01 for the last parameter word of ACK/NAK. Bits 29 to 36 (zzzzzzzzzz) are set to the parameter information identification (PID) of the NAK data.

Item 2706 is called the best server response and 8 bits 19 to 26 are encoded as follows: bit 19&20(DD) is the digital color code of the best server (0 to 3); bit 21 is 0; bits 22 through 26 (nnnnnnn) is a 5-bit offset count from the number of best server channels serving the initial paging channel of the cellular system. That is, 00000-334 for B side or 333 for a side and 10100-354 for B side or 313 for a side.

The 2709 entry is called the extended address word and always occupies word position 3 when it is incorporated into the data information from the handset to the pico station. This word is solicited by the pico station from the handset to allow capture of the handset electronic serial number for comparison with a list of allowed pico station users to avoid unauthorized system access. The handset includes word 3 in its full registration message to the pico station.

FIG. 28 depicts the data message components used by a pico station in establishing its attach (OHD) and transmitting command words to a handset. These words are 40 bits in length rather than the 48-bit words used by the handset.

The items in fig. 28 are described by their defined message locations. Items 2801 (OHD word 1), 2802(OHD word 2) and 2804(OHD control pad word) strictly follow the EIA-553 standard. Item 2803 (OHD word 3) is established to allow a pico station to transmit a unique identifier in the form of a 22-bit base station serial number to allow the handset to identify the pico station of its associated pico mode within those short periods of time that the pico station actually transmits the additional message stream.

Item 2805 (command word 1) strictly follows the EIA-553 standard and is used by pico stations as a single word command for handset paging and as the first word in a multi-word command to the handset.

Item 2806 (command word 2) is the second word in the two-word best server command sent by the pico station to the handset.

Item 2807 (Command word 2) is the second word in the two word Access Accept message that the pico station sends to the handset when access is denied.

Item 2808 (Command word 2) is the second word in the two word Access Accept message that the pico station sends to the handset when access is accepted and the line is idle. A local domain NNN of 000 to 101 is allocated to the local unit for this handset access.

Item 2809 (command word 2) is the second word in the two word access accept message sent by the pico station to the handset if there is a busy line condition. If the mobile phone is busy, the local NNN is 110.

Figure 29 depicts additional pico station command words used in communicating with a traffic control unit and a handset operating in pico mode.

Item 2901 (command word 1) is a single word attention message sent on a common control channel to a service control unit requesting service.

Item 2902 (command word 1) is the first word in a multi-word answer message sent to the service control unit at the time of configuring/updating the session.

Item 2903 (command word 2) is the second word of the audit trail sent to the traffic control unit at the time of the positioning session.

Item 2904 (command word 3) is the second word of the two-word ACK/NAK acknowledgement from the pico station to the traffic control unit at the time of the configuration/update session.

Item 2905 (command word 2) is the second word of the multi-word parameter information transfer process that is performed in the handset authorization operation. This command alerts the handset to follow the parameter information command.

Items 2906 (command words 3-N) are parameter information command words including a parameter information identification field (PID) and a parameter value field (PVAL) described in table 1.

TABLE 1

PID parameter name (PVAL) bit/length

00000001 number of channels used 5

00000010 Transmission Power level 3

00000011 Access threshold RSSI 8

00000100 alarm threshold RSSI 8

00000101 suspend threshold RSSI 8

00000110 RSSI sample interval 4

00000111 RSSI average count 4

00001011 base number NPA 12

00001100 base number NNX 12

00001101 base telephone number LINE 16

00001110 handset pico station count 2

00010001 optimal server identification 9

00010010 Call Forwarding on command 16

00010011 Call Forwarding off Command 16

00010100 registration number 3 for mobile telephone

00000000 termination session (11111111)

Figure 31 depicts the data message composition used by the service control unit in communicating with the pico station. The length of these words is 48 bits.

Item 3101 is called a non-deniable access message and is transmitted as a single word command.

Item 3102 is the first word of a multi-word command message sent by the service control unit to a particular pico station.

Item 3103 is the second word of the parameter information command message.

Item 3104 is the second word of an ACK/NAK acknowledgement transmitted to the pico station after receiving the request data.

Item 3105 is the second word of a two-word shutdown command that forces the pico station to terminate all pico operations and monitor the common control channel for other instructions.

Item 3106 is the second word of a two-word reset command that forces a reset in the pico station.

Item 3107 is the second word of a two-word full audit command directing the pico station to respond with traffic, operating parameters, failure and diagnostic information.

Item 3108 is the second word of a two-word partial audit command directing the pico station to respond with traffic, failure and diagnostic information.

Item 3109 is the second word of the two-word terminate session command to release the pico station from this communication session.

Fig. 30 depicts data message formats and timing for both the forward channel direction (pico-to-handset) and the reverse channel direction (handset-to-pico-station). As shown, the data message formats strictly follow the EIA-553 standard in terms of their transmission duration and their data word repetition and order.

One difference between the ground station protocol and the base station protocol for cellular as defined in EIA-553 is that commands transmitted to a target handset are transmitted simultaneously on both word a and word B streams in a forward command channel format, which ignores the normal cellular ground station stream assignments based on the MIN of the target handset. The cellular ground station sends commands to two different handsets respectively by means of word a and word B streams.

Another distinction between the mobile station protocol for cellular use and the handset pico-mode protocol involves the use of coded digital color code fields in the reverse control channel message stream. In pico mode, this field is set to all 1 s at the time of access attempt message transmission, and all other message transmissions are set to the digital color code assigned by the target pico station. This is done to avoid that the network cellular system erroneously attempts to handle this pico-mode access event once the signal mixing results in a message being acquired by the cellular network.

Pico station configuration procedure

Referring now to the drawings, and in particular to fig. 7-13, the process steps relating to operation of a pico station will be explained in more detail. Fig. 7 depicts the main idle loop of the program. The pico station activation operation is divided into a configuration procedure described in fig. 8, and an authorization procedure described in fig. 9. The call processing functions are illustrated in fig. 10-13, respectively.

Obviously, at the time of purchase, the pico station has not been activated for use by the user. The configuration operation is performed "over the air" by the service control unit after the pico station has been placed in the premises where it is used. As explained earlier, several service control units and a host station are distributed in the coverage area of each serving pico station, together with a host comprising a server to generate a list of service control unit locations that can reach a given pico station location.

The base station activation operation includes additional events associated with a standard subscriber activation system used by a bearer or service provider of the cellular system. In this regard, the user activation process includes a number of standard cellular carrier systems for identifying and authorizing to serve all activated standard cellular telephones. In addition, the pico station ESN is captured at the point of sale by the user activation system. The subscriber activation system communicates this ESN to the service control system host along with the address and phone number of the location where the pico station is desired to be used. The subscriber activation system also communicates to the service control system host the Mobile Identification Number (MIN) and ESN for each handset authorized to use the pico station.

The control system host examines the pico station location address and selects the most likely service control unit through which association between the associated control unit and the target pico station can be accomplished. The system host then sends a command to each selected service control unit to request that the target pico station complete its positioning task. Each selected control unit then periodically sends out a non-repudiation access message addressed to the target pico station ESN on the common control channel. This message will be repeated periodically until the control association with the target pico station has been completed.

Referring now to FIG. 7, when a user installs a pico station at a desired location and connects its power supply, the pico station enters an initialization task 701. After power-up, the central processor of the pico station then issues a power-on reset command and initiates a task 702 that performs a deterministic housekeeping operation to place the phone line interfaces of the pico station's wireless and pico stations in their idle states. The pico station central processor then uploads the contents of its EEprom in task 702 and initializes task 703 to determine the pico station operational status.

If the job status check in query task 703 determines that the pico station is not yet configured, a pre-configuration task is entered and the status LED is set to red in process task 705. During task 703, if it determines that operation of the pico station has been configured, a query task 704 is initiated to determine if the handset associated with the pico station has been authorized.

If a negative result is obtained at task 704, or if a positive result is obtained at task 710, the pico station proceeds to task 715 to tune to the common control channel. Following task 715, query task 716 determines whether the service control unit requires pico station access.

If access is not required, the pico station begins to establish the handset authorization process of figure 9. If access is required, the pico station adjusts the traffic control access requirements as illustrated in figure 8.

If task 704 determines that the handset is authorized, this means that at least one handset has successfully downloaded the pico-mode operating parameters during the authorization process. A positive result of query task 704 initiates query task 710 to determine whether the red authorization button on the pico station has been pressed. If the button is not pressed, query task 711 is entered to determine if the telephone line status has changed. If the phone line status is new, task 712 is entered, each registered handset is updated to this result and the pico station returns to the idle state through the scan channel routine. If the phone line status has not changed as determined by task 711, the pico station begins the scan channel process of FIG. 10.

If the operation is not allowed, query task 703 initializes process task 705. In task 705, the pico station central processor instructs the wireless pico station to alternately tune to a known a-side common control channel and then a B-side common control channel to monitor whether additional messages have been received from the control unit.

Query task 706 is then performed to determine if a control unit is present. If a negative response is obtained, a loop is executed back to the beginning of task 706, and the query task is repeated until a control unit is found. If a positive response is identified, task 707 is entered to determine: whether a non-repudiation access message from the control unit is addressed to the selected pico station due to the subject ESN. If not, a loop is executed back to the beginning of task 706.

If the non-denied access message from the control unit is addressed to the target pico station, the pico station starts the configuration process in figure 8. There, the pico station transmits a communication setup confirm message to the control unit at full power. The control unit measures the signal strength of the received pico station signal and then issues a terminate session command to the pico station. The pico station then exits the configuration process and returns to the main loop entry 720.

After issuing the terminate session command to the pico station, the service control unit reports the result of its locate command to the host. The master, in turn, analyzes the results from all the commanded traffic control units and selects the one with the strongest received signal from the pico station as the master control for the position of this pico station. The system host then forwards all of the selected traffic control units that need to be forwarded to the pico station's operating parameter transmission. This data is included in an activate command sequence.

After the service control unit receives the activation command sequence, the following events are initiated. The control unit queues up a pico-station configuration session with the target pico-station. The control unit initiates this session by first transmitting a non-repudiation access message addressed to the target pico station on the common control channel. The pico station replies with a communication setup confirm message described in process task 802 of the pico station configuration procedure.

After receiving the command for confirming the communication establishment of the pico station, the control unit transmits the parameter information to the pico station by using a standard parameter information message format, and the pico station confirms the receiving of the parameter information message.

The remaining processing task flow for the configuration process is further illustrated in FIG. 8. Processing task 801 begins processing task 802 to perform the control unit access function, sending a communication setup confirmation to the control unit. Query task 803 determines whether this is an initial configuration procedure performed by the pico station. If not, a start command timer task 804 is initiated. If it is an initial configuration process, enter task 805 clears the EEprom random access memory map register of the pico station. After clearing the register, task 806 captures and acknowledges receipt of the best server identification. Task 807 then captures and acknowledges receipt of the power level assignment, and task 809 captures and acknowledges the handset assignment after tasks 807, 808 capture and acknowledge receipt of the number of operating channels of the pico station. Task 810 captures and validates the working mode assignment and termination session commands and task 811 saves the random access memory image into EEprom.

After performing tasks 805 and 811, task 812 clears all the service registers in the pico station and sets the status LED to green. After task 812 is successfully executed, the pico station returns to the main loop processing task shown in FIG. 7.

Any NAK from a pico station will cause the traffic control unit to issue a retransmitted parameter information message. If all messages are successful, the control unit will issue a terminate session command to the pico station and report the activation of the pico station to the system host. The control unit then saves a data file relating to the ESN index of the pico station, including the parameters assigned to the pico station, to its hard disk.

The service control element access event initiates a configuration function update procedure beginning with query task 815 following the initial configuration result of procedure 804. The query task 815 determines whether a command from the control unit addressed to the pico station has been received. A positive result will initiate query task 816 when the watch command timer action expires.

A negative result of query task 816 returns to the beginning of query task 815 to continue monitoring for control unit commands. The expiration of the command timer forces a positive result at query task 816 and returns to the main loop at entry 720.

Receipt of the command will result in a positive result at query task 815 and initiate query task 817 to detect a new configuration assignment from the control unit. A positive result of task 817 initializes process task 818 to capture and acknowledge changes in its configuration to the pico station.

Processing task 818 then begins processing task 819 to restart the command timer and returns to the beginning of query task 815 to await further commands.

If the command is not a configuration change, a negative result of query task 817 begins query task 820 of determining whether a terminate session command was received.

A negative result of query task 820 returns to the beginning of query task 815 to await further commands.

When query task 820 determines a terminate session command, an affirmative result begins processing task 821 to acknowledge the termination of the control unit session.

Processing task 821 then begins processing task 822, saving the new configuration data to EEprom, and returns to the main loop at 720.

The pico station, after receiving its initial configuration information, can enter a pre-authorization task and wait for a manual press of an authorization button or further contact with the service control unit. The pico station status LED will display a steady green color indicating that the user handset authorization will be completed.

Mobile phone authorization process

The consumer must authorize each of his handsets to use his pico station. This process is formulated to avoid unauthorized use of the pico station and the telephone line connected thereto. The process also establishes the entire coverage area over which the pico station and handset will communicate. The physical location of the pico station is also determined in this process by comparing the cellular best server information collected by the handset during the authorization setup process with the information provided to the pico station by the service control unit during the configuration process.

Referring now to figures 7, 9, 16, and 19, authorization operations involving both handset and pico station processing tasks will be described.

The handset to be authorized must be powered up and in the cellular idle state indicated by task 1901. Query task 1902 will detect whether the user has pressed a menu key. Query task 1903 then monitors the Base Station Auth selection made by the cell phone menu function and exits to task 1905 which displays the Base Station Auth and begins cell phone authorization task 1601. The handset must be brought into the vicinity of the pico station because the processing tasks are done at very low transmit power and each component requires very strong signal levels to avoid inadvertently visiting any nearby pico station.

The consumer must then press the authorization button on the pico station, which is detected by the query task 710 in the main loop task 720. A positive result from query task 710 initiates handset authorization task 901. The pico station monitors the On state of the button in query task 902 and starts a button press timer via task 903. Query task 904 monitors whether the button is still On when the key times out. If the button is Off, a negative result of query task 904 will cause a return to query task 902, whereas a negative result of the button On test will cause task 901 to return to main loop 720. The key timing is set to 500 milliseconds to ensure that the switch is absolutely closed before further processing tasks are performed.

If the result of query task 904 is positive, the pico station performs task 905 to tune the pico station transmitter to a known setup/control channel and begin transmitting the grant overhead signal stream 3002 over the forward control channel. This overhead stream includes pico station words 2801, 2802, and 2803. The pico station then starts a ten second grant timer in task 906.

Referring now to fig. 16, execution of the handset grant task 1601 results in a process task 1602 in which the handset is tuned to the common/control channel and a ten second grant timer is started. Query task 1603 monitors the signal strength at the forward control channel of-60 dbm or greater. If a pico station signal is not present, query task 1605 monitors for a timeout of the ten second grant timer. If the result of task 1605 is affirmative, task 1601 exits to cordless idle at gate 1420. Otherwise, a negative result of query task 1605 results in a return to query task 1603 to again monitor signal strength.

Once query task 1603 determines sufficient signal strength, query task 1604 monitors for the occurrence of a pico station grant overhead flow. A positive result of query task 1604 initializes query task 1605 to again detect the timer expiration.

A positive result of query task 1604 initiates processing task 1606 to allow the handset to begin transmitting its three-word authorization stream 3005, which includes words 2701, 2707, and 2709. Word 2707 the local domain will include an "I'll take it." call answer message. This transmission conforms to section 2.6.3.5 of EIA-553 of the handset reverse control channel message.

If the pico station query task 907 does not receive a signal from the handset at a level of-60 dbm or higher, it will not acknowledge the transmission. In association with that process, handset query task 1607 monitors the pico station busy/idle bit in the forward control channel overhead flow. The handset will stop transmitting after transmitting 104 bits without detecting a forward control channel busy/idle bit change from the pico station. A negative result of cell phone query task 1607 transfers task 1601 to process task 1624, which delays the task by a random time >10 milliseconds <200 milliseconds. An inquiry task 1605 is then initiated directing the handset to resend its authorization stream. The handset is programmed to make these transmissions at its power level 7 (approximately 2mw output).

The pico station query task 907 monitors the handset's signal level and if it is not above the minimum, task 908 monitors the expiration of the 10 second grant timer. If the timer has not expired, the pico station returns to query task 907 and re-detects the handset signal level.

If query task 908 detects that the timer has expired, the pico station performs process task 909, turns off the transmitter and stops the LED from flashing (if ON) and reverts back to the main loop at 720. The handset will detect the loss of signal from the pico station through query task 1603 and terminate its authorization timer, which, as detected by query task 1605, will return the handset to its cellular idle task through the cordless idle entry door at 1420.

When query task 907 measures sufficient signal strength from the handset, the pico station performs processing task 910, during which the pico station captures the handset MIN and ESN data. Query task 911 monitors whether the captured ESN and MIN are in a list of allowed handsets that were handed over to the pico station by the service control unit during activation. If the handset is not expected by the pico station, a negative result of query task 911 initializes process task 909 to terminate the authorization process. A positive result of query task 911 initiates a process task 912 of requesting and capturing cellular best server information from the handset.

A positive result of the handset query task 1607 initiates a query task 1608 for monitoring pico station-60 dbm or higher signal strength. If the pico station does not receive the handset's ESN and MIN, query task 1608 will detect the loss of the signal and its negative outcome exits through cordless idle at 1420, forcing termination task 1609. A positive result of the query task 1608 initiates a query task 1609, monitoring for the best server commands from the pico station. Failure to receive this command will cause task 1601 to return to query task 1608 to again monitor signal strength.

When query task 1609 detects the best server command, it initiates process task 1610, causing the handset to transmit the cellular best server information to the pico station.

Task 1610 then initiates a query task 1611 that searches to identify control padding overhead from the pico station indicating that the link has been successfully established in order to continue the authorization process. A negative result of query task 1611 initiates query task 1612 to monitor for a sufficient signal level. An affirmative result of task 1612 returns to query task 1611. A negative result of 1612 is returned through the cordless idle gate 1420.

The pico station processing task 912 produces the best server data capture, passing task 901 to processing task 913, which will transmit a stream of control padding words 2804 on the forward control channel and cause the pico station LED to start flashing. Query task 914 then compares the acquired best server data to a list of allowed cellular best server data that the service control unit downloaded to the pico station during the configuration process.

If the pico station data does not match the cellular best server data, a negative result of query task 914 initiates a process task 909 which terminates the process. This indicates that the pico station has changed its location after it has been configured by the service control unit.

Receipt of the control pad word results in a positive result of query 1611 and initiates processing task 1613. The handset will begin flashing its backlight display in response to processing task 1613 and indicating successful activation of authorization after query task 1611 detects this stream of initialization control pad words. The handset will then enter its parameter transmission cycle. During this session, the handset light will blink continuously during the time that the pico station signal remains above the-60 dbm level, or until the pico station issues a terminate session command at the completion of the session.

An affirmative result of query task 914 passes control to the pico station parameter transmission loop. This cycle transmits the parameter information message 2902 to the handset using the parameter information message format described in 3001.

The pico station parameter transmission cycle begins with a process task 915 that starts a periodic timer. Task 901 then initializes a processing task 916 that formats and transmits a first parameter information message on the forward control channel, followed by a stream of control pad words. Query task 917 then monitors for ACKs from the handset. If the result of query task 917 is a negative result, query task 918 is initialized to monitor whether the cycle timer is still running. A positive result of query task 918 initializes process task 916 whereby the last message is retransmitted. If query task 918 determines that the cycle timer has expired, the negative result initializes process task 909 to terminate the current process.

A positive result of query task 917 initializes query task 919 and monitors the completion of the parameter information list. A negative result of query task 919 initializes process task 915, overriding each of the remaining parameters. A positive result of query task 919 initializes process task 920, transmitting a terminate session command on the forward control channel, causing the LED to stop flashing, and the process loops back to the main loop through 720.

The handset parameter translation loop includes a query task 1614 to monitor the pico station signal strength, a process task 1615 to capture the parameter information message and send an ACK or NAK response on the reverse control channel 1615, and a query task 1616 to monitor for a terminate session command from the pico station. Task 1601 can exit this loop when query task 1614 detects a loss of signal, followed by initialization processing task 1622. Processing task 1622 turns off the backlight flash and returns the handset to cordless idle through the cordless idle entry at gate 1420.

When query task 1616 detects a terminate session command, task 1601 controls initialize query task 1617 to compare this pico station sequence number with the numbers of all previously authorized pico stations. A positive result from query task 1617 initializes process task 1623, which deletes the information previously stored in this pico station slot. Processing task 1623 then passes control to processing task 1621, which stores the parameter information collected during this authorization period in the EEprom of the handset.

A negative result of query task 1617 initiates query task 1618, monitoring the multi-pico station authorization of the handset. Each handset is capable of storing and communicating with up to 3 different pico-station messages. If the multi-pico station is not authorized, a negative result of query task 1618 initializes process task 1623. A positive response to query task 1618 initiates query task 1619 to determine whether the pico station authorization count has been reached. A positive result of query task 1619 initializes processing task 1622 and discards the save processing task. A negative result from query task 1619 initializes process task 1620, increments the count of stored pico station data files and initializes process task 1621, saving the files in EEprom and then returns cordless idle through the cordless idle entry at 1420.

Pico station main loop

Referring back to FIG. 7, the pico station exits the authorization operation through the main loop gate at 720. The query task 703 identifies the occurrence of the service control unit activation event and initializes the query task 704, detecting the occurrence of the handset authorization event. A positive result of query task 704 initiates query task 710, 710 monitors the status of the authorization button. A negative result of query task 710 initiates query tasks 711, 711 to monitor the status of the telephone lines connected to the pico station. Once query task 711 determines that the line status has changed, it initiates processing tasks 712, 712 which then issue update commands to all registered handsets. A negative result of query task 711 transfers control to the scan channel task at gate 1001.

The pico station will spend most of its time in an idle loop, monitoring line status and activity using the telephone line interface, and wirelessly scanning all channels assigned to handset or service control unit access attempts using the pico station.

The pico station will exit the pico station idle loop to transmit:

a. responding to an access attempt from a registered handset thereof;

b. an update signal to the registered handset in response to the change in the state of the telephone line;

c. when a signaling for registering the incoming call of the mobile phone is sent;

d. when a handset is an active participant in a telephone call;

e. when an authorization button on the pico station is pressed; and is

f. Responding to a non-rejectable access message from the traffic control unit.

At other times, the pico station is in a scan receive mode and the pico station transmitter is off.

In order to transmit, the pico station must monitor the availability of the selected channel, i.e., independently of the transmissions of other units. This is done by measuring the Received Signal Strength Indication (RSSI), which provides a value on the channel being examined that represents the amount of RF energy present at the pico station location. The pico station is preset by the traffic control unit to a busy channel RSSI tolerance value above which a channel will be considered in use by the monitoring unit and therefore cannot be used by the pico station for any transmission.

Mobile phone registration process

Both pico stations and handsets operate in a limited RF coverage environment by controlling transmit power and establishing minimum signal levels for each other's access.

Considering that one channel is active for an access attempt of the handset, the pico station is also preset by the service control unit at an access minimum RSSI level below which an access attempt will not be responded to by the pico station. In addition to controlling the coverage area of the pico station, another purpose of this access minimum RSSI is to allow the pico station to identify channels with acceptable signal levels and quickly transfer to a channel on which the handset can attempt to gain access at an acceptable signal level.

When the handset position analysis process detects that the handset is in the coverage area of the best serving cell site that also covers the pico station, a registration process is initiated by the handset during the rescan task. The handset then periodically attempts to access the pico station by selecting an idle channel from among the multiple channels given in the authorization process as long as the handset remains in the best service coverage area. This registration attempt lasts long enough to allow the pico station to scan all channels and also time to detect a handset registration attempt and respond to the handset.

Referring now to fig. 10, 14, 15 and 17, the handset registration process will be described.

The pico station proceeds to a scan channel task 1001 and performs a process task 1002 to tune the pico station receiver to the first of a plurality of channels assigned for use by the pico station. Control is then given to query tasks 1003, 1003 to monitor the channel, checking whether the received signal strength is above the access threshold level assigned to the pico station by the service control unit during configuration. It is desirable that the access threshold level is set at a level above a warning threshold or an interruption threshold. Thus, if the user's handset is allowed access, the user will have some margin to move around without the communication being automatically interrupted.

If insufficient channel levels are present, a negative result of query task 1003 initializes process tasks 1004, 1004 to increment the channel number and tune the receiver to the new channel. Processing task 1004 then initiates query tasks 1005, 1005 to compare the current channel number to the maximum allowed channel number. If the channel number has not exceeded the maximum number, a negative result of query task 1005 returns to query task 1003 to check the signal strength on the newly selected channel. Query task 1005 initiates query tasks 1013, which monitor local timer behavior if the maximum channel number is exceeded.

If the local timer is not running, a negative result of query task 1013 initializes process tasks 1018, 1018 to cancel all handset registrations for the pico station. Task 1010 then moves back to entry 720 of the main loop.

The handset performs a slightly idle task according to the EIA-553 rescan standard. This task enters and initiates query tasks 1418 at 1420, 1418 to monitor whether the handset is in local idle mode. A negative result of the query task 1418 initiates the query tasks 1401, 1401 to monitor the pico-station data fill by the authorization process described above. A positive result of the query task 1401 initializes the handset registration process in 1701.

The handset enters handset registration and proceeds to utility tasks 1515, 1515 tuning the handset to the first of the multiple channels designated for use by the pico station in processing tasks 1516 at 1701. The initial inquiry tasks 1517, 1517 then monitor the received signal strength on that channel to determine if it is below the suspend threshold level provided to the handset during the pico station authorization process described above. This is the RSSI level that the handset uses to determine a busy channel. If query task 1517 determines that the channel is not below the minimum value, then negative results initialization process tasks 1519, 1519 increment the channel number and tune the handset to the new channel. Processing task 1519 then initiates query task 1520.

Query task 1520 monitors the selected channel number and compares it to the maximum allowed channel number. If the channel number does not exceed the maximum value, a negative result of query task 1520 initiates query task 1517 to detect a signal level on the newly selected channel. A positive result of query task 1520 initializes process task 1521, returning a failure to task 1701. Query task 1702 detects the failure and initiates process tasks 1707, 1707 start the find base timer with a short count value to ensure a quick return to this process. Control then returns to the rescan task at entry 1402.

Once query task 1517 detects an acceptable channel, it initiates process 1518 to return OK. Satisfying query task 1702 initializes process task 1703, then starts an access timer and causes the handset to begin transmitting "Here I Am I" message words 2701 and 2702 using 3006 format. Processing task 1703 then initiates query task 1704.

Query task 1704 monitors the forward control channel for signals from the pico station above the access threshold level. If no such signal is present, a negative result of query task 1704 initializes query tasks 1705, 1705 to monitor access timer running status. A positive result of query task 1705 initiates query task 1704, which again monitors for signals from the pico station. When query task 1705 detects an access timer timeout, a negative result initializes process task 1706.

Processing task 1706 stops the transmission from the handset and will restart the found base station timer at its standard value. The task 1706 then returns to the rescan task through an entry at the gate 1402.

Pico station query task 1003 will answer yes when the handset signal is sufficient and task 1001 controls initiation of query task 1006 to monitor for the presence of 10k bits of manchester encoded data on the received signal. If query task 1006 does not detect data, a negative result initiates process task 1004 to tune to the next channel. A positive result from 1006 initiates a query task 1007, 1007 analyzing the content of the received data stream to identify a handset authorization registration message.

The handset authorization registration message identified in task 1007 may be an initial registration that occurs when the handset first enters the pico system from the standard or macro cellular system or a reacquisition registration that occurs when the handset last registered in the pico system.

A positive result of query task 1007 initiates processing tasks 1008, 1008 which perform the handset registration process and then exits to the main loop through entry 720. The registration process may be an extended registration process that includes a security check on the initial registration. It may be a shorter procedure for reacquisition registration. For example, for reacquisition, task 1008 may simply restart the local timer associated with the handset as discussed above in connection with task 1013. A negative result of query task 1007 initializes query task 1009.

Query task 1009 monitors the received data messages for the presence of a service control element access request. A positive initialization processing task 1010, 1010 of the query task 1009 sets the service control unit access flag and starts the base station idle task in 1101. A negative result of query task 1009 initializes query tasks 1011, 1011 to monitor the received data message for the presence of a handset access request. A positive result from query task 1011 initiates process task 1012, 1012 setting the handset access flag and initiating 1101 a base station idle task.

A negative result of query task 1011 returns to process task 1004 to increment to the next channel and continue scanning.

The base station processing task 1008 starts a local timer upon successful termination of the registration process. This timer is a register that holds the event value of the event plus 300 seconds. Query task 1013 detects this non-zero timing register and passes the positive result to query task 1014.

Query task 1014 monitors the current time value against each non-zero stored value of the local timing register. An affirmative result of query task 1014 initializes processing task 1015 if the current time equals or exceeds the stored value, cancelling the registration for the handset because the pico station was not reacquired within the allowed time window.

However, although the registration is cancelled, the handset can later be recaptured without going through the entire registration process. For example, a cell phone may fail to recapture due to a power loss. As long as the handset remains within the same picocell after being powered back up, it will attempt reacquisition and the picocell base station will receive the reacquisition attempt. On the other hand, if the handset finds itself powered up outside the picocell, it will go through the entire registration procedure the next time it encounters the picocell.

Control then passes to an initialize inquiry task 1016 that monitors to determine if any handsets remain registered. A negative result of query task 1016 returns to the main loop at entry 720. A positive result of query task 1016 initializes process task 1017 which performs an update process task informing the registered handsets of their status with the pico station. Process task 1017 then initiates a base station idle task at 1101.

Base station idle task 1101 proceeds to query task 1102 to monitor the ring voltage on the premise line. A negative result of query task 1102 initiates query task 1103 to determine whether the service control unit is requesting access for updating or auditing.

A positive result of 1103 initializes process task 1105 to tune the base station to the common control channel and ACKs (acknowledgments) access to the traffic control elements. Process 1105 initiates a query task 1106 to analyze the SCU command for a configuration update. A positive result of query 1106 transfers control to the base station configuration task at 801. A negative result of query 1106 initializes query task 1107 to determine whether the command of the service control unit is for auditing purposes.

A negative result of query 1107 exits through processing task 1111, which ends the access of the service control unit and returns to the main loop at 720.

If this is a review session, a positive result of query task 1107 initializes process 1108. Process 1108 transmits the requested audit (all or part) data to the service control unit and initiates a query task 1109.

Query task 1109 monitors for a clear service registration command from the service control unit and a positive result of it initiates process task 1110 to reset all service registers to zero.

Both processing task 1110 and the negative result of query 1109 initialize processing task 1111, end the access session for the service control unit and return to the main loop at 720.

Referring again to fig. 17, the base station processing task 1008 causes the pico station to transmit its three word stream of registration overhead messages (words 2801, 2802, and 2803) on the forward control channel using format 3002. Handset query task 1704 will detect the presence of a signal on the channel and initiate process task 1708, starting a data capture timer. Query task 1709 then monitors the channel for 10k bits of manchester encoded data. A negative result of query task 1709 initiates query task 1701 and monitors the operational status of the data capture timer. An affirmative result of query task 1701 returns to query task 1709 to again monitor the data. A NOT OUTPUT INITIATION PROCESS TASKET 1711 from QUERY TASKET 1701, which causes the handset to cease transmitting "Here I Am! The message starts the find base timer with a short count value to quickly return to this processing task.

A positive result of query task 1709 initiates query task 1712, which monitors for the pico station to register for messages in overhead format. A negative result of query task 1712 initializes process task 1717, ends the registration attempt, restarts the find base station timer with a normal value, and returns to the rescan task at entry 1402. A positive result of query task 1712 initiates the processing overhead tasks at 1713.

Processing the base overhead task then initiates a query task 1714 that compares the digital color code received in the registration overhead message with the digital color code stored for this pico station. If not, a negative result of query task 1714 initializes process task 1717.

A positive result of query task 1714 initiates query task 1715 by monitoring whether the received system identification is a SID stored for this pico station. A negative result of query task 1715 initializes process task 1717. A positive result of query task 1715 initiates query task 1716 by comparing the received pico station sequence number with the stored series number for this pico station. A negative result of query task 1716 initializes process task 1717. A positive result of query task 1716 initiates query task 1718 by monitoring the pico station overhead flow for an idle status of the busy/idle control bit. A negative result of query task 1718 also initiates query task 1719 by monitoring whether the number of consecutive busy states encountered reaches a maximum allowed count value.

If the maximum count value is not exceeded, a negative result of query task 1719 initializes query task 1718 and retests the busy/idle bit status. Once the maximum value is exceeded, a positive result of query task 1719 initiates process task 1717, ending the registration attempt.

A positive result of query task 1718 initiates process task 1720 to cause the handset to send its 3-word registration message to the pico station. This message includes words 2701, 2702, and 2709 sent in 3005 format. The processing task initializes an inquiry task 1721 that receives a response from the pico station. The receive reply message from the pico station includes a two word combination of one of 2805 and 2808 or 2809 sent in 3003 format.

Receipt of a negative result initialization process task 1717, which causes query task 1721, ends the registration attempt. A positive result of query task 1721 initiates processing task 1722, which captures the local handset unit number setting from the pico station. Processing task 1722 then initializes processing task 1723.

Processing task 1723 performs an automatic call forwarding notification function with cellular switching. This function activates call forwarding for any incoming call directed to the MIN of the handset. These calls will be forwarded to the pico station telephone number via the cellular switch. Processing task 1723 then initializes processing task 1724.

Processing task 1724 sets the local flag (H-Idle is true), clears the cellular Idle flag (C-Idle is false), sets the transmit enable flag (XMIT is true), and starts the reacquisition timer. In addition, task 1724 saves the identity of the pico station that the handset registered. This identification is stored in non-volatile memory. If this identification is not changed, the handset will attempt to quickly reacquire the pico station after power up without going through the longer full registration process discussed below. The task 1701 then returns to the rescan task at the cordless idle entry 1420.

When a handset is initially powered up, task 1400 is performed. Task 1400 initializes the handset. Following task 1400, a query task 1427 identifies the identity of the pico station with which it last communicated, if any. In a preferred embodiment, the picocell identity is set to zero when the handset registers with the macrocellular system. The non-zero code identifies a pico station. If task 1427 finds that the picocell identification is zero, program control proceeds to task 1403 to determine the appropriate macrocellular system from which cellular service can be sought.

If task 1427 finds a nonzero picocell identification, task 1428 loads the internal data table corresponding to the identified picocell station. Such data tables are loaded with programming for SIDs, power levels, active channel numbers, and the like. Following task 1428, program control proceeds to a reacquisition gate 1801 to reacquire the identified pico station. By reacquiring the pico station, the entire registration process is eliminated. By eliminating the entire registration process, the handset can communicate with its pico station soon after power up. Thus, a user can turn off his or her handset but within an authorized picocell, hear the telephone ringing through the landline system, power up the handset, and quickly answer the telephone.

If the handset fails to locate the pico station, a rescan task is returned via the entry at 1402. Control passes to a query task 1403 that determines the appropriate system from which cellular service may be sought. The system identification assignment is specific to either a non-wired (always odd on side a) or a wired (always even on side B) service provider.

Query task 1403 monitors whether the SID stored by the handset is an even value, and if so, initializes process task 1404. A negative result of query task 1403 initializes processing task 1405.

Process task 1404 selects a B-side setup/control channel and process task 1405 selects an a-side setup/control channel. Two process initialization tasks 1406 scan selected channels seeking cellular service according to the EIA-533 standard. Control then initiates a query task 1407 to monitor the results of this search for cellular service availability.

If no traffic is available, a negative result of query task 1407 initializes the busy scan entry at gate 1500, which initializes query task 1501. Query task 1501 monitors the pico station lookup status, and a negative result initializes process task 1502 and starts a timer for finding pico stations. The process task 1502 returns to the rescan task at gate 1402 to re-find cellular traffic.

If query task 1407 is answered in the affirmative, initialization query task 1408 monitors the local idle flag for true. This test is part of the second line functionality which allows registered handsets to complete call origination using the cellular network when the house line is busy.

An affirmative result of query task 1408 indicates that this rescan event is a second line attempt and initiates process task 1409 to display Premium on the handset.

Processing task 1409 initiates query task 1423, which checks the overhead global message for local identification. A positive result of query task 1423 initializes process task 1424, which replaces the Premium display with a Local display on the screen.

Both processing task 1424 and a negative result of query task 1423 initiate query task 1410, which monitors the dialed digit buffer for a call to 911. An affirmative result of query task 1410 falls back to the cellular call task at output number entry 1917.

If query task 1410 determines that this second line attempt is not a call to 911, a negative result initiates the dial entry process at 2000.

A negative result of query task 1408 initiates query task 1411, which compares the SID of the available cellular system with the cellular SID stored for this handset. If so, a positive result of query task 1411 initiates query task 1412 by checking whether the state of the cell idle flag is true to determine whether it is the first time through this loop.

A negative result of query task 1412 initializes process task 1413, which issues a call forwarding off command to the cellular switch to return a call to the handset MIN to the handset. Task 1413 also stores the picocell ID of zero in non-volatile memory. Unless this ID value is rewritten upon subsequent pico station registration, the handset will look for a null picocell ID in task 1427 after power up and stop attempts to reacquire the pico station. Processing task 1413 then initializes processing task 1414 to set the cell idle flag to true, ensuring that access is only passed through this loop once. Processing task 1414 initiates a find base timer and initiates a query task 1415. A positive result of query task 1412 or a negative result of query task 1411 both initializes query task 1415.

Query task 1415 monitors the best server identification established during the search for cellular traffic and compares it to the stored best server identifications, which represent the best servers for each pico station that the handset is authorized to use.

The term best server refers to the identity of the cell site that provides the strongest signal from the cellular system to the handset. Each cell site is uniquely identified by the setup/control channel number it uses and the digital color code of the message stream assigned to it.

Since the cell site provides coverage over a limited area, the handset can limit its search for a pico station to those instances where the handset is physically within the coverage of the best server cell site closest to the pico station location.

It should be appreciated that this technique greatly reduces the number of unnecessary transmissions from the handset and greatly improves the availability of pico-station channels for calls.

Once query task 1415 identifies a match for a best server, its affirmative result initiates query task 1416 which monitors for a base station timer activation. A positive result of query task 1416 initializes process task 1417 if the find base timer is running.

Processing task 1417 displays the Premium word on the screen of the handset to indicate to the user that the cellular system is providing service and that there is a space-time usage charge. Processing task 1417 then initiates query task 1425 which monitors the content of the overhead data stream emanating from the cell site. Each cell site in the cellular system has a new message appended to the normal overhead flow. This is a local control message, in accordance with the global action message format specified by EIA-553. The 16 bit local field of this message is encoded with the regional identification of the cell site.

Each handset has a list of zone identifiers that are loaded during the authorization process. Query task 1425 compares the received region identification to this table, and if a match results in a positive output of query 1425. A positive result initializes process task 1426 to display the word Local instead of Premium.

Negative results for both process task 1426 and query task 1425 return to the cellular idle task at 1901.

It will be appreciated that the ability to display on a handset, a multi-location sensitive service availability message greatly enhances the customer's ability to make decisions on how much, if any, a call may incur when placing or receiving a call at a given location.

Query task 1416 detects that the find base timer has expired and will produce a negative result, initiating the handset registration task at 1701.

Mobile phone idle mode

The local handset unit number is dynamically assigned by the pico station and changes as the handset enters and leaves the service area of the pico station.

Upon accepting registration of a handset, the pico station starts a local timer for the device. The registering handset must reacquire the pico station before this timer expires or the pico station cancels its registration.

The activity of the pico station in a telephone call will stop the pico station local and handset reacquisition timers when an unrelated handset is prohibited from transmitting. The handset responds to the OHD message from the pico station to cause the pico station to reset the corresponding local timer to a value equal to the time of the event plus 300 seconds.

Each handset also starts its internal reacquisition timer upon receipt of the pico station's registration. The interval of this timer is set to 270 seconds, i.e. 30 seconds less than the pico station local timer.

When the handset reacquisition timer times out, the handset attempts to reacquire the pico station by locating an idle channel and sending a "Here I Am2 Access at Registration" message.

The pico station will respond to this message by repeating the registration sequence described earlier.

Each time the handset fails to reacquire the pico station, the counter is incremented. If this reacquisition failure counter reaches a maximum count, the handset is forced to switch to the cellular network and attempt to get service there. The handset resets its reacquisition failure counter for each successful reacquisition by the pico station and restarts the reacquisition timer.

This process will be described in more detail with reference to fig. 14, 15 and 18.

The flow from handset registration task to rescan task proceeds at cordless idle portal 1420 to query task 1418, which monitors the local idle flag for true. A positive result of query task 1418 initiates a process task 1419 to display the specified local unit number on the handset indicating that the user's pico station is providing service. Processing task 1419 initiates the monitor base station task at entry 1503.

Monitor base station task initialization query task 1504 monitors the reacquisition timer condition. If this timer has not expired, a positive result of query task 1504 initiates a monitor base station loop at process task 1506. Process task 1506 then tunes the handset to the original pico station channel and initiates query task 1507.

Query task 1507 monitors the channel for the presence of a signal above the access threshold. If a high signal is not present, a negative result of query task 1507 initiates process task 1511, increments the selected channel by 1, and initiates query task 1512.

Query task 1512 monitors the handset's keypad for user actions. If a key is pressed, query task 1512 initiates a cordless call initiation task at entry 2200. If no keypad action is detected, a negative result of query task 1512 initiates query task 1513 to compare the selected channel number to the maximum allowed channel number. If the selected channel number is greater than the maximum, a positive result of query task 1513 initiates query task 1504 to retest the state of the reacquisition timer. Until this point, a negative result of query task 1513 returns to query task 1507 to monitor the selected channel for the presence of a signal from a pico station.

When query task 1507 detects the presence of a signal, a positive result initiates query task 1508, which monitors for the presence of 10kbit manchester encoded data. If the signal present is not data, a negative result of query task 1508 initiates processing task 1511 to skip to the next channel. A positive result of query task 1508 initializes query task 1509 if data is present.

Query 1509 checks the data stream for pico station commands directed to this handset, and a positive response will initiate the task of handling base station commands at entry 2400, as specified in the EIA-553 standard. A negative result of query task 1509 initiates query task 1510, which checks whether there is overhead (information) in the data stream from the pico station. A positive result of query task 1510 initiates the process base station overhead task at entry 1713.

If the data flow is not an authorized pico station, a negative result of query task 1510 initiates process task 1511 to check the next channel.

The handset scans all allowed pico station channels through and then returns to query task 1504 to test the reacquisition timer condition.

The handset will spend most of the pico-mode idle time in this scanning cycle to monitor pico-station activity that may involve the handset.

When the reacquisition timer times out, a negative result of query task 1504 initiates common task 1515 to find available channels as previously described. A positive result of the common task returns to query 1505 to test the found channel. A negative result returns to query 1504 to restart the process.

When a free channel is found, a positive result of query task 1505 initiates the reacquire pico station task at 1801.

The reacquisition base station task 1801 begins with a process task 1802 that starts an access timer to limit the duration of the attempt. Processing task 1802 then causes the handset to start in the reverse control channel direction of the selected channel, sending a message stream in 3006 format that includes words 2701 and 2704 "HereI Am2 Registration".

Process task 1802 initiates a query task 1803 to monitor the forward control channel direction of the selected channel for the presence of a signal from the pico station that exceeds the access threshold level. If the pico station does not respond, a negative result of query task 1803 initializes query task 1814 to monitor for access timer conditions. A negative result of query task 1814 initializes process task 1815 upon expiration of the access timer.

Processing task 1815 stops transmitting on the reverse control channel and increments the failure counter. Processing task 1815 then loads the reacquisition timer with a smaller value to ensure a quick return to this task.

Control then passes to query task 1816 to monitor whether the value of the failure counter is equal to the maximum number of failures allowed (three). If the failure to reacquire the pico-station task reaches a maximum count, query task 1816 falls back to process task 1817.

Processing task 1817 clears the local idle flag, clears the reacquisition timer, and starts the find base station timer. This action effectively cancels the handset from the local state. Processing task 1817 then loops back to the rescan task at rescan entry 1402.

If the failure timer has not reached the maximum count, a negative result of query task 1816 returns control to the cordless idle entry of the rescan task at 1420.

Once query task 1814 detects an access timer timeout, a positive result of which initiates query task 1803 to continue looking for pico station signals. When sufficient signal is detected 1803, a positive result initiates the process task 1804.

Processing task 1804 starts a data occurrence timer and initiates a query task 1805 to monitor for the occurrence of 10K bits of manchester encoded data. If data is not present, a negative result of query task 1805 initializes query task 1818 to monitor for a data presence timer. If the timer expires, a negative result of query task 1818 initializes process task 1815.

While the timer is running, a positive result of query task 1818 initiates query task 1805 to retest if data is present. When query task 1805 detects data, a positive result initiates query task 1806 to test whether there is overhead in the data stream. If the data message is not an overhead, a negative result of query task 1806 initializes process task 1815.

A positive result of query task 1806 initiates query task 1807 by comparing the digital color code in the received overhead stream with the digital color code stored for this pico station. If the numerical color codes do not match, a negative result of query task 1807 initializes process task 1815. A positive result of query task 1807 initializes query task 1808 if the numeric color codes match.

Query task 1808 compares the received system identification with the stored SID for this pico station. If they do not match, a negative result of query task 1808 initializes process task 1815. A positive result of query task 1808 initiates query task 1809 by comparing the received pico station sequence number with the sequence number stored for this pico station. A negative result of query task 1809 initializes process task 1815. A positive response to query task 1809 initiates query task 1810.

Query task 1810 monitors whether the busy/idle bit in the forward control channel overhead is idle. If the busy/idle bit is busy, a negative result of query task 1810 initializes query task 1819, counts the failures and compares the count to the maximum number of failures allowed. If the maximum value is reached, a positive result of query task 1819 initiates process task 1815. A negative result of query task 1819 initializes query task 1810, again testing for a busy/idle status.

A positive result of query task 1819 initiates process task 1811 to cause the handset to send a three-word registration message to the pico station. This stream includes words 2701, 2703, and 2709 transmitted in 3005 format on the reverse control channel. Processing task 1811 initializes query task 1812.

Query task 1812 monitors the response that the pico station received this registration. The response of the pico station includes a two word message in 3003 format using one of words 2805 and 2808 or 2809.

If the pico station fails to accept the handset, a negative result of query task 1812 initializes process task 1817 to exit local service. A positive result of query task 1812 initializes process task 1813 to perform the internal housekeeping required to update the handset state of the pico station. This processing task also clears the failure counter and restarts the reacquisition timer. Processing task 1813 then exits to the rescan task at cordless idle entry 1420.

Cellular idle

When the handset leaves the coverage of the picocell, it becomes an active cellular handset. Referring to fig. 19, handset operation in cellular idle mode processing at 1901 proceeds to query task 1902, which monitors for the actions of the menu keys discussed previously.

If the menu key is not pressed, a negative result of query task 1902 initiates query task 1906 to test the action of the talk key. A negative result of query task 1906 initializes process task 1904 to perform the normal cell idle function specified in EIA-533. Process 1904 falls back to the rescan task at cordless idle entry 1402.

If query task 1906 detects the talk key On, a positive result initializes query task 1907 to test service availability. If service is not available, a negative result of query task 1907 falls back to the rescan task at cordless idle port 1420.

If query task 1907 detects traffic, a positive result initializes the dial input task at 2000.

Mobile phone joining an ongoing call

A pico station constantly monitors the status and condition of the telephone line to which it is connected. Once a call originates from one of the home extensions that is also connected to this telephone line, the following events occur:

a. the pico station will send out an update message to each of its registered handsets. The local field of this update message represents the line status as "busy" (word 2809);

b. each handset will display "line taken" instead of Home #, informing the user that someone is using the house line.

The pico station allows any of its registered handsets to join the ongoing call. With reference to fig. 10, 11, 12, 13, 19, 22, and 23, the event of a handset joining the call is described.

When the handset user presses the off-hook (green) key in pico mode, this event is detected by query task 1512 in the monitoring base station task, initiating the cordless call initiation task at portal 2200.

Cordless call initiation task initiate query task 2201, monitor the On state of the green key. If not, query task 2201 falls back to process task 2202, processes all other first keystrokes, and then returns to cordless idle task 1420. A positive result of query 2201 initiates query 2203, which checks whether the green key was generated in response to a ringing event. A positive result of query 2203 initializes the answer call task at entry 2120. A negative result of query task 2203 initiates the acquire pico station task at 2210.

The Capture pico station task 2210 initializes the common task at 1515 to find an available channel. When query task 1515 is completed, return is made to query task 2211.

A negative result of task 2211 initializes 1916 a recorder task to generate a recorder sound to the user indicating that no call origination was received. A positive result of task 2211 initializes process task 2212, starting the Access timer and causing the handset to begin transmitting an "I wait In1 Access Request" message In the reverse control channel direction of the selected channel. This message, including words 2701 and 2706, is sent in 3006 format. Processing task 2212 then initiates the contact pico station task at entry 2301.

The pico station will detect the handset access request message in query task 1011 and its affirmative result initiates process task 1012, setting the handset access flag before starting the base station idle task at 1101.

The associate base station task 2301 initiates a query task 2302 to monitor the forward control channel direction of the selected channel for the presence of signals from pico stations that exceed an access threshold level. If a high signal is not present, a negative result of query task 2302 initializes query task 2312 to monitor access timer conditions.

The idle task then proceeds to query task 1102, which monitors the line for a ringing voltage. A negative result from query task 1102 initiates query task 1103 and monitors the service control unit access flag as true. A negative result from query task 1103 initiates query task 1104 by monitoring the handset access flag for true. A negative result from query task 1104 returns to the main loop at entry 720. A positive response from query task 1104 initiates processing task 1112.

Processing task 1112 captures the handset ESN/MIN and dials the number if ready. Control then initiates a query task 1113 to compare the captured ESN/MIN with handset data authorized by the pico station. If the query task 1113 results in no, control passes back to the main loop at entry 720. An affirmative response from query task 1113 initiates an initiate or join call task at entry 1201.

The initiate or join call task 1201 initializes the process task 1202 to perform an update for all registered handsets, informs the occupied state of the handsets, and initializes the process task 1203. Processing task 1203 sends an appropriate response message to the handset (receives words 2805 and 2808 if the line is idle; or voice channel assignment if the line is busy). The pico station waits for a handset response in a process task 1203.

If the access timer is running, an affirmative result of query task 2312 returns to query task 2302, which again detects a signal from the pico station. If the query task 2312 responds no, an initialization process task 2312 stops sending access messages from the handset, counts the failures to contact the pico station and puts a reduced count value in the reacquisition timer. Processing task 2312, then initiating query task 2314.

Query task 2314 monitors the contents of the dialed digit buffer for the occurrence of a 911 emergency call because entering this process is a result of a failure to contact the pico station.

If the result is positive, query task 2314 immediately exits the acquire pico station task and enters a rescan task at entry 1402 to attempt to find service from the cellular network to complete the emergency call.

If 911 is not the dialed number, a negative result of query task 2314 initiates query task 2315 where the failure count is compared to the maximum number of failures allowed. If the count is at the maximum, a positive result of query task 2315 initiates processing task 2316 to cancel the handset local state. Processing task 2316 is completed by clearing the local idle flag, clearing the reacquisition timer, and starting the find base station timer. Processing task 2316 then returns to the rescan task at rescan entry 1402.

If query task 2315 does not detect the maximum failure count, a negative result is returned to the rescan task at cordless idle entry 1420.

When query task 2302 detects a signal from a pico station, a positive result initializes process task 2303, starts a data occurrence timer and initializes query task 2304.

Query task 2304 monitors the forward control channel direction of the selected channel for the presence of 10K bits of manchester encoded data. If data is not present, a negative result of query task 2304 initiates query task 2317 to monitor for a data presence timer. A positive result of query task 2317 initiates query task 2304, which again tests whether data is present. If query task 2317 provides a negative result, initialization process task 2313 ends the access attempt.

When query task 2304 detects the presence of data, query task 2305 is initialized, the received digital color code is compared to the digital color code stored for this pico station to detect a match, if the result is No, processing task 2313 is initialized to terminate the access attempt, if the result is Yes, query task 2306 is initialized.

Query task 2306 checks whether the pico station response message is a voice channel assignment command specified by EIA-553. If the result of query task 2306 is negative, then query task 2318 is initiated, checking if the pico station response message is received in the word 2805 and 2808 formats.

A negative response from query task 2318 initiates query task 2319, which checks for the presence 911 of the contents of the dialed digit buffer. A positive response from query task 2319 initiates a rescan task at rescan entry 1402 attempting to find cellular service to handle the emergency call. If the result of query task 2319 is negative, a re-order task at 1916 is initiated, informing the user that the call cannot be processed.

A positive result of query task 2318, or a positive result of query task 2306, initiates processing task 2307, causing the handset to send a two-word response message to the pico station as a reply. Query task 2308 is then initiated to monitor whether a voice channel assignment is received from a pico station. A negative result of query task 2308 initializes query task 2321.

Referring now to fig. 12, a pico station processing task 1203 captures the handset response and initiates a query task 1204, testing whether the line state is idle. A negative result of query 1204 is generated when the join call function is performed. This causes task 1201 to fall back to 1315 where the house line is captured. A positive result from query task 1204 initiates query task 1205 to check whether a dial from the handset is received. A negative result of query task 1205 initializes process task 1208, starts a dial-in timer, and initializes query task 1209. Query task 1209 monitors the dial capture from the handset. A negative result from query task 1209 initiates query task 1210, monitoring the condition of the dial-in timer.

A negative result of query task 1210 forces task 1201 to exit by updating handset portal 1323. An affirmative result from query task 1210 returns to query task 1209. An affirmative result of query 1209 returns to processing task 1203, which issues an ACK. An affirmative result from query task 1205 initiates a process task 1206 to capture the house line. Processing task 1206 initializes query task 1207 to monitor whether the dial-out process was successful. If the result of query 1207 is negative, task 1201 exits through the release line entry at 1322.

A successful dial-out will produce a positive result of query task 1207 causing task 1201 to initiate a switch to talk mode process at entry 1316.

Query task 2321 monitors whether the purpose of the access attempt with the dial ready to go through is to capture a pico station event. A positive response to query task 2312 initiates process task 2323 to maintain the handset in a transmit state and to pass the dialed number to the pico station for processing. Control then passes back to the originating task at call entry 2204.

If query task 2321 is negative, then process task 2322 is initiated, the handset transmitter is turned off and the dial from the user is captured at dial entry 2000 back to the initiating task.

A positive result of query task 2308 initiates a process task 2309 to tune the handset to the specified voice channel assignment (same physical channel). Query task 2310 is then initiated to monitor whether the received line status of the pico-station is busy. If the result is negative, query task 2321 is initiated. A positive result of query task 2310 initializes query task 2311 if the line is busy.

Query task 2311 monitors whether the contents of the dialed digit buffer is a call to 911. A positive result initiates a rescan task at rescan entry 1402. A negative result of query task 2311 initializes process task 2320 to keep the handset transmitter on and back to the initiating task at call entry 2204.

The initiate task call entry at 2204 proceeds to query task 2205, which monitors for a transmit enable flag to be true. A negative response to query task 2205 initializes process task 2208 to display a handset busy message on the display screen and returns control to the rescan task at cordless busy entry 1422. A positive result initializes query task 2206.

Query task 2206 determines whether the pico station has allocated a voice channel for the call. A negative response to query task 2206 initiates query task 2209, which determines whether the user placed an emergency call. A positive response from query task 2209 returns a rescan task at rescan entry 1402. A negative response from query task 2209 falls back to the reorder task at entry 1916, notifying the user that the call failed to be handled.

A positive result of inquiry task 2206 initializes process task 2207 to perform normal call functions. Call termination transfers control from processing task 2207 back to the rescan task at cordless idle entry 1420.

Once the call is established, the pico station processing task 1316 initiates a fast on/off cycle at query task 1317 which monitors the progress of the call. A positive result of query task 1317 initiates query task 1318, monitoring for fast on-off from the handset. If the response to query task 1318 is negative, query task 1319 is initiated.

FIG. 32 shows a flow chart that further illustrates the process followed by the pico station in task 1317. As shown in fig. 32, query task 3201 determines whether the call is ended. When the user of the handset presses the on-hook button, the call is terminated, causing the handset to turn off the monitoring tone (SAT) and transmit a 1800ms burst tone. Alternatively, the far end of the call may tear down the call, returning the dial tone to the telephone line. If either of these events causes the call to end, program control exits through a "No" exit of task 1317.

If task 3201 determines that the call has not ended, query task 3202 determines whether an internal timer has expired. The internal timer is a free running clock operating in background mode, which may be periodically timed out. In a preferred embodiment, the interval timer times out every 15 seconds. Program control exits via the "OK" exit of task 1317 as long as the interval timer has not expired.

Task 3203 updates the RSSI running average if task 3202 determines that the interval timer has expired. In the preferred embodiment, the signal strength is averaged over the last four time intervals of the interval timer. Following task 3203, query task 3204 checks this running average to determine whether the signal strength falls below a power down, a connection teardown, or a HANGUP threshold. In a preferred embodiment, the power down threshold is programmed to be a lower RSSI signal strength than the access threshold level (see table 1 above). Thus, when a pico station guarantees access to a handset, the user is free to move around the point where access is guaranteed, without being suddenly alerted to what to do or suddenly powering down.

If the signal level is above the power down threshold, task 3205 clears the warning flag and program control exits through an "affirmative" exit from task 1317. If task 3204 determines that the signal strength is below the power down threshold, task 3206 checks the warning flag to determine if it is set. If not, program control exits via the "OK" exit of task 1317. However, if set, execution of task 3207 powers down the handset, and program control exits through a "No" exit of task 1317.

By powering down the handset, the provision of communication services to the handset is stopped and the call is ended. The handset is powered down because its signal level drops to a low level indicating that it is at the picocell edge. A power down threshold is programmed to keep the picocell small enough to prevent interference from other picocells in close proximity. However, the handset does not power down unless it was alerted in a previous time interval. If the handset is not alerted, it will not power down, or if any previous alert was generated a long time ago, the handset will not power down.

Referring back to FIG. 13, if the response to query task 1318 is positive, an initialization process task 1320 transmits a fast on/off from the handset to the telephone central office, followed by initialization of query task 1319.

Query task 1319 monitors the received signal level from the handset and compares it to the disconnect warning level. A positive response from query task 1319 initiates process task 1321 to issue a warning command to the handset. The disconnect warning level is an RSSI signal strength between the access level and the power down or on-hook level. In addition, task 1321 sets the warning flag described above to power down the handset for the next time interval when the signal level is not improving, as discussed above in connection with tasks 3204 and 3206. The communication is controlled using a voice channel as is well known in the art of cellular telephony by sending an alert message to the handset to issue an alert command. The handset responds to this warning message by issuing a warning to the user so that the user can know that steps are to be taken to prevent power loss. For example, the user should gradually move closer to the base station. Both process task 1321 and the negative response from query task 1319 will initiate query task 1317 to continue monitoring the call for a teardown event.

When query task 1317 detects a call teardown event, process task 1322 is initiated. Processing task 1322 then releases the line and initiates processing task 1323, performs updates to all registered handsets, notifies them of the existing line status and removes the handset occupancy message from their display. Processing task 1323 then returns control to the main loop at entry 720.

During this call connection, other home extensions can join or leave the call at will. The pico station will maintain the connection of this phone line to the handset until one of the following disconnect events occurs:

a. the pico station does not detect the detection sound from the mobile phone within 5 seconds;

b. the user presses the on-hook button to turn off the detection tone and transmit an 1800ms burst signal tone;

c. the remote unit detaches from the call and returns a dial tone to the telephone line.

d. The average measured RSSI of the handset falls below the disconnect RSSI level.

If the reason for the call ending is a.

Fig. 33 shows a flowchart describing the tasks performed in the normal call function 2207. Task 2207 performs normal telephony functions for the cordless mode of operation. Task 1915 performs similar telephony functions for the megacellular mode of operation, as discussed below.

Normal talk function performs query task 3301 to determine if a voice channel control communication is received. The present invention contemplates performing voice channel control communications in a manner similar to that described in EIA-553. If no voice channel control communication is received, query task 3302 is performed to determine if the handset is still off-hook. As long as the handset remains off-hook, the call continues and program control returns to task 3301.

When task 3302 determines that the handset is no longer off-hook, the user of the handset has hung up and the call now needs to be torn down. Task 3303 performs call termination processing, consistent with EIA-553 where the handset is the first party to terminate the call. After task 3303, program control exits normal talk function 2207 or 1915. The call has been completed.

Referring back to task 3301, when a voice channel control communication is detected, query task 3304 is performed to determine whether the control communication is a release command. The release command informs the handset that the other party has ended the call, and task 3305 then performs call end processing consistent with the handset's EIA-553 specifications. After task 3305, program control exits normal talk function 2207 or 1915 and the call has been completed.

When task 3304 determines that the control communication is not a release command, query task 3306 determines whether the control communication is a warning command, such as discussed above in connection with task 1321. When a warning command is detected, query task 3307 is performed to return program control, etc. to-be-detected tone (SAT). As is common with voice channel control communications, SAT is removed when such control communications occur, but is restored after the communications are completed. When the SAT disappears, the call is muted, but the call may continue when the SAT returns. The typical mute time is short and not noticeable to the user. Program control remains at task 3307 until the SAT returns.

Task 3308 mutes microphone 57 (see fig. 2) when the SAT returns so that no sound signal is emitted from the handset. Task 3309 then issues a special alert to the user. In the preferred embodiment, this notification takes the form of an audible signal played at the handset speaker 56 (see FIG. 2). In the preferred embodiment, the sound is a triplet of beeps, approximately 50ms on and 50ms off. The use of audible rather than visual notifications is because the user typically places the phone near his or her ear when receiving the alert command and does not necessarily notice a visual notification. Since the microphone is muted, the alert will not be heard by the other party to the call and the call flow is less likely to be interrupted. After task 3309, task 3310 validates a microphone so that sound can be transmitted to the other party to the call. After task 3310, program control returns to task 3301 and the call continues. As mentioned above, in the preferred embodiment, the handset user has a predetermined time interval equal to 15 seconds between which to emphasize the signals received by the pico station. Typically, the user needs to move towards the base station in order to achieve this.

Referring back to task 3306, when a control communication is received that is not a release or warning command, the handset may perform the task of analyzing any number of control communications and then perform task 3311 to appropriately respond to other types of control communications. Typically, such other types of control communications are not received while operating in the cordless mode specified by task 2207. However, when operating in the macrocellular mode specified in task 1915, the handset can receive power control commands, handover commands, and the like. After the response in task 3311, program control returns to task 3301 and the call continues.

Base station-handset call initiation procedure

When the pico station is in idle mode, the telephone line is connected but not occupied, and any of the registered handsets can initiate a telephone call.

The conventional cellular handset dialing process is significantly different from the general PSTN dialing process. The benefit of the invention is to restore the normal PSTN dialing procedure to the handsets of the system operating in pico and cellular modes.

The method is realized by enabling the mobile phone to generate an internal accurate dial tone; removing the dial tone when the first dialed digit is entered; analyzing number entry versus north american numbering plan; and automatically send the number to the network upon detecting that the entry is complete. Cellular customers will quickly adapt to this system because they are not forced to learn new procedures.

Referring to fig. 19, 20, 21, a handset call origination process will be described.

When the user of the handset presses the off-hook (green) key, the process flow described previously for the handset to join an ongoing call will proceed up to the dial input at 2000.

The dial-in task at 2000 initiates a query task 2001 to determine whether it is pico mode or cellular connection by monitoring the local idle flag for true. A negative result of query task 2001 initializes process task 2005. A positive result from query task 2001 initiates query task 2003 and monitors for a transmit flag to be true. A negative result from task 2003 initiates process task 2004 to display a handset busy message on the display screen and returns to the rescan task at cordless busy entry 1422.

Cordless busy entry 1422 initiates inquiry task 1421 as part of the second wire selection process. Query task 1421 monitors whether the green off-hook key is pressed, with a positive result returning to the rescan task at query 1403, as previously described. A negative result of query task 1421 initiates monitoring of the base station at entry 1503.

If the send flag is true, a positive result of query task 2003 initializes process task 2005, clears the digit collection buffer, resets the digit counter to zero and sets the maximum expected digit count to seven. Control then transfers from 2005 to process task 2006.

Processing task 2006 turns on an internal precision dial tone generator to indicate to the user that a call may be placed. The processing task 2006 then initiates a query task 2008 at the digital capture portal 2007. The query task 2008 monitors whether any key is pressed.

A negative result of query task 2008 initiates query task 2009 to monitor service availability by checking the signals transmitted by the pico station on the selected channel, comparing its level to the disconnect level if H-Idle is true, and checking for macrocellular service if C-Idle is true. If query task 2009 does not recognize the presence of traffic, a negative result initiates process task 2013, removing the dial tone and returning to the cordless idle task at entry 1420.

With business available, a positive result of query task 2009 initializes query task 2021, testing local idle as a true state. A negative result from query 2021 initiates query task 2011. A positive result from query 2021 initiates query task 2010, monitoring for a true flag. If query 2010 results in a negative, the dial input task exits through the busy exit at 2021. A positive result from query task 2010 also initiates query task 2011, which checks for incoming timer conditions.

A negative result of query task 2011 indicates that the user has not made the intended input. A query task 2012 is initiated to monitor the digital buffer for an empty status. If some number numbers have been collected, a negative result of query task 2012 initiates the speed dial task at entry 1908.

An empty buffer allows the affirmation of the query task 2012 to transfer control back to the loop at the process task 2005 where the collect digital loop process is initiated. A positive result of query task 2011 initializes task 2008.

When task 2008 detects the pressing of a key, a positive result initializes query task 2014, detecting the condition that local idle is true. A negative result from 2014 initializes query task 2016. An affirmative result of query task 2014 initiates query task 2015 of checking whether the second off-hook (green) key was pressed within two seconds of the first off-hook of the originating call. The handset uses that procedure to bypass the pico mode of the pico station. This is a second line function that allows the user to force a call to the cellular system. One reason for making this selection may be to make an important call while the premises line is busy. A positive response from the query task 2015 causes an exit from the initiating task and a rescan task to be entered at entry 1402.

A negative response to query task 2015 initiates query task 2016 to check if the pressed key is a numeric key. A negative result from query task 2016 initializes the non-numeric input task at entry 2102. The non-numeric entry task at 2102 proceeds to a query task 2109 that monitors for clear key presses. If the response of task 2109 is positive, query task 2110 is initiated, which checks the digital buffer for an empty status. If the buffer is empty, a positive result of query task 2110 initializes the dial-in task at start entry 2000. This action turns the dial tone on.

If the dialed digit buffer is not empty, the negative response of query task 2110 performs a task 2111 of removing the last digit entry from the digit buffer and decrementing the digit counter by one. Control is then given to query task 2112 to check the digital buffer for an empty status after this deletion. A negative response from task 2112 initiates a digital acquisition cycle at digital capture input 2007. If task 2112 finds the digit buffer empty, its affirmative result will restart the dial entry task at 2000, storing the dial tone for the user.

If the response to query task 2109 is negative, an initialize query task 2113 monitors for a pressed first key as being the (#) key. The key is used for the mobile phone to redial a number key. A positive response from query task 2113 initiates processing task 2114 which retrieves the number of the last call and places it in a number buffer. Processing task 2114 initiates query task 2115 to monitor whether the digital buffer is empty.

If the response to query task 2115 is affirmative, a return is made to the start of the dial entry task at 2000. If the response to query task 2114 is negated, process task 2116 is initiated, the dial tone is removed and the dial completion task at entry 2020 is initiated.

If the first key entered is not the (#) key, a negative response at 2113 occurs initiating query task 2118, which monitors for whether the first key pressed is the (#) key. A positive response from 2118 initializes process task 2119, removes the dial tone and initializes process task 2120. Processing task 2120 saves (#) in the digital buffer and initializes processing task 2107, starting the running of the inter-digital timer. The processing task 2107 returns control to the digital acquisition loop at the digital capture portal 2707.

If the first input is not one, a negative response from query task 2118 initiates process task 2121, generates a burst of error tones to the user and then initiates process task 2107, starting the inter-digit timer.

Referring back to FIG. 20, if the key pressed is a numeric key, a positive result of query task 2016 initiates a process task 2017, saves the number in a number buffer, and increments a number counter by one. Control then passes from task 2017 to query task 2018, which compares the numeric count output to a maximum numeric count. A positive response to query task 2018 initiates query task 2019 by monitoring the local idle-true state to direct the initiating task to the appropriate service. A negative result from query task 2019 passes control to the outgoing digital task at entry 1917 and the call will be processed in the cellular network. A positive result of query task 2019 initializes the acquisition base station task at 2213.

If all desired digits have not been entered, a negative response from query task 2018 initiates the digit enter task at 2101 in FIG. 21. The digit entry task proceeds to query task 2103 where the first dialed digit is monitored. A positive response from query task 2103 initiates process task 2104, which removes the dial tone signal and initiates query task 2105, which monitors whether the first digit is a 1 or a 0, which indicates that a billing call has been made. A positive response from task 2105 initiates process task 2106 to reset the maximum value of the digital counter to 11. Both the negative result of query 2103 and the negative result from task 2105 initialize query task 2108.

Query task 2108 compares the digits accumulated in the digit buffer to the north american dialing plan to detect a dialing completion status. A positive response from the query task 2108 initiates the dial completion task at 2020. A negative response to task 2108 initializes process task 2107 to restart the inter-digit timer.

This unique dialing scheme for handsets, which uses a digit counter to handle tasks, an inter-digit timer to handle tasks, and a comparison with the NANP standard and an internal accurate dial tone generator, allows the user to quickly enter the number desired to be dialed. This, in turn, gives cellular and other special handsets the benefits of using dial tones and being easily familiar with dialing protocols, without the need for the send and end key functions.

By passing control from the query task 2012 of the digit capture task 2007 to the speed dial input at the mouth 1908, the handset also internally supports speed dialing by inter-digit timeouts of the non-empty digit buffer. Control proceeds to query task 1909 to monitor whether the value of the digit counter is less than or equal to three, allowing up to 200 speed dial memory registers. A negative response from query task 1909 initializes a dial completion task for entry at 2020. A positive response from query task 1909 initializes query task 1910.

Query task 1910 monitors whether the value of the digital buffer falls between 1 and 199 speed dial register values. A negative response from the query task 1910 initializes 2020 the dial completion task for the entry, while a positive response initializes the processing task 1911 to restore the contents stored at the selected memory location and place it in the digital buffer. Processing task 1911 initializes query task 1912.

Query task 1912 monitors the digital buffer for an empty state. A positive response to task 1912 causes a return to the beginning of dial entry task 2000. A negative response from query task 1912 initiates the dial completion task entered at entry 2020, placing the call.

The dial completion task at 2020 proceeds to query task 2019 where the route is determined as described above.

A cellular origination process initialization process task 1913 for the outgoing number at entry 1917 initiates a call to the cellular network with the number accumulated for use as the destination address. Processing task 1913 initiates query task 1914 at cellular call entry point 1918.

Query task 1914 monitors whether a voice channel assignment is received from the cellular switch. Once the call is not completed, a negative result from query task 1914 initiates processing task 1916, which generates a recorder sound to alert the user that the call is not completed. Control then transfers from the processing task 1916 back to the rescan task at the idle entry 1420.

If the result of query task 1914 is positive, control passes to normal cellular call functionality at task 1915. Once the call is completed, processing tasks 1915 return control to the rescan task at cordless idle entry 1420. The normal cellular call function tasks 1915 are described in more detail above in conjunction with fig. 33.

The acquire pico station entry initialization process task 2214 at 2213 In fig. 22 turns on the handset transmitter and begins sending an "I grant In2 Demand" message to the pico station on the selected channel. Control then passes from process task 2214 to contact pico station task 2301, discussed above.

Referring again to fig. 12, the pico station detects the access required message and captures the dialed number from the handset. The processing task 1203 sends out a voice channel response and captures the handset's acknowledgement as previously described. Processing task 1203 initializes inquiry task 1204 to monitor the house line idle state.

A positive response from query task 1204 initiates query task 1205, monitoring for dial capture. A positive response from task 1205 initializes process task 1206. Process task 1206 seizes the premises wiring and initiates query task 1207, detects the dial tone and dials the number captured from the handset to the network. Failure to complete the dial processing task initiates processing task 1322 and ends the call.

Successful completion of the query task 1207 switches the initialization 1316 to a call processing task to a call mode as described in the EIA-553 standard. Control passes to the fast on-off monitoring cycle described previously.

During this call connection, other house extensions can join or leave the call at will. The pico station will keep this phone line connected to the handset until a disconnect event occurs.

Each registered handset may receive a new assignment of cell numbers from the pico station if the activated handset is no longer present in the service area of the pico station causing the call to end.

Base station handset call ending procedure

During the pico station idle task, the phone line interface will alert the pico station of an incoming call by detecting the presence of a ringing voltage on the line. The pico station then immediately initiates the call termination process.

The call ending process is described with reference to fig. 9, 11, 13, and 24.

As previously described, the pico station scan channel task will initiate a base station idle task at entry 901 after processing the active local timer. The pico station will not be involved in the call activity unless the handset is local.

The base station idle task proceeds from entry 1101 to query task 1102 to monitor the premise line for a ringing voltage. A positive response from query task 1102 initiates the end call process at 1300.

Control passes to process task 1301 which starts a ring back timer at five second intervals. North american telephone systems use a two second on, four second off ring period.

Process task 1301 initiates process task 1302, finds free pico station channels and issues paging commands to each authorized handset. This action includes collecting responses of the handset to paging commands. This processing task follows the EIA-553 message configuration standard.

The handset monitoring base station task will detect the pico station paging command during query task 1509 and will initiate the process base station command task at 2401. The entry at 2401 handles the base station command task initialization query task 2402, comparing the type of command with the paging command. A positive response from query task 2402 initiates query task 2403.

Query task 2403 monitors whether the pico station busy/idle bit is idle. A negative response from query task 2403 initializes query task 2405, counts failures and compares the failure counts to the maximum failure count allowed. A positive response to task 2405 causes the exit processing base station command task and initiates a rescan task at cordless idle entry 1420.

A negative response from query task 2405 initializes query task 2403 based on the test busy/idle bit status. A positive response from query task 2403 initiates process task 2404, which sends an acknowledgement signal to the pico station. Processing task 2404 then initiates a rescan task at cordless idle entry 1420.

Base station processing task 1302 then initiates query task 1303 which monitors all responses from the paged handsets. A negative result from query task 1303 returns to the base station idle task at 1101 and then initializes the processing task again. A positive response from query task 1303 initializes process task 1304.

Processing task 1304 will issue an Alert order to each handset that has an ACK' D page command.

The handset will capture the command in the monitor base station task of query task 1509 and restart the process base station command task at entry 2400. Control again initiates query task 2402 to monitor for paging commands. A negative response from query task 2402 initiates query task 2406, monitoring for warning commands. A positive response from query task 2406 initiates query task 2407, monitoring for a warning on command. A positive response from query task 2407 initiates process task 2408, activating an internal ringer in the handset to alert the user to the incoming call. Processing task 2408 then initiates a rescan task at cordless idle entry 1420.

The pico station processing task 1304 then initiates a query task 1305 monitoring for a reply from the house extension. A positive response from query task 1305 initiates process task 1311, issuing a release command to each handset being alerted.

Processing task 1311 then issues an update command to notify the handset of the line occupancy status. Control then returns to the base station idle task at entry 1101.

A negative response from query task 1305 initiates query task 1306 which monitors for an answer from the handset. A negative result from query task 1306 initializes query task 1307, again detecting a line ringing state. A positive response to query task 1307 initiates processing task 1308 which restarts the ring back timer for another five second interval. Processing task 1308, and the negative results of query task 1307, both initialize query task 1309.

Query task 1309 monitors for receipt of acknowledgements from all handsets. A negative response to query task 1309 initializes process task 1312 to issue a paging command to each handset that does not respond. Processing task 1312 initializes processing task 1313 and issues a warning on command to each responding handset. Processing task 1313 and a positive result from query task 1309 both initiate query task 1310.

Query task 1310 monitors for a ring back timer condition. If the timer expires, the system determines that the caller has hung up. As a result, a positive response initialization task 1311 of query task 1310 ends the call. A negative response from query task 1310 returns to query task 1305, which again tests for a response from the house extension.

Referring now to fig. 24, a negative result of processing base station order query task 2406 initializes query task 2410, monitoring for a release order from the pico station. A positive result of the query task initiates a process task 2411, turns off the alert ringer, returns a disconnect response and initiates a rescan task at cordless idle entry 1420.

A negative result from query task 2410 initiates query task 2412, monitoring for update commands from the pico station. A positive result from query task 2412 initializes process task 2413, captures the new state and initializes query task 2414. A negative result from query task 2412 returns a rescan task at cordless idle entry 1420.

Query task 2414 monitors whether the busy/idle status of the pico station is idle. A negative response from query task 2414 initiates query task 2421, counts failures and compares the accumulated count to the maximum number of failures allowed. An affirmative result from query task 2421 returns a rescan task at cordless idle entry 1420. A negative response from query task 2421 returns to query task 2414, again testing for busy/idle status.

A positive result of query task 2414 initiates process task 2415, confirms the update and initiates query task 2416. Query task 2416 monitors whether the update command is a cell phone busy message. A negative result of query task 2416 initializes query task 2422. Task 2422 monitors whether the update command is a line seizure message. A negative result of query task 2422 initializes query task 2423. Task 2423 monitors whether the update command is an idle message. A negative response to query task 2423 returns a rescan task at cordless idle entry 1420.

The off-hook key is pressed when the user wishes to answer an incoming call. This action is detected by the monitor pico station function of query task 1512 and a negative result thereof initiates a call initiation task at ingress 2200.

As explained previously, initiating task entry 2200 initiates query task 2201, monitoring the off-hook (green) key press status. A positive response to query task 2201 initiates query task 2203, monitoring the alert ringer on state. A positive response from query task 2203 initiates the answer call task at entry 2122.

Referring now to fig. 21, answer call task entry 2122 initiates query task 2123, monitoring the busy/idle status of the pico station. A negative response from query task 2123 initiates query task 2129, counts the failures and compares the accumulated count value to the maximum allowed number of failures. A positive result from query task 2129 returns to the rescan task at cordless idle entry 1420. A negative response from query task 2129 initializes query task 2123, again testing for the busy/idle status.

A positive response from query task 2123 initializes process task 2124 to send an "I'll Take It" message to the pico station. Process task 2124 initiates query task 2125 to monitor for acknowledgements from the pico stations.

Referring now to FIG. 13, the pico station detects an answer from the handset in the query task 1306 of the initialization process task 1314. Processing task 1314 issues a warning off command to all other handsets, acknowledges the "I'll Take It" message from the answering handset and issues an update command to all other handsets. The update command is a message instructing the handset to display "handset occupied" or the like. In this mode, all other handsets cannot get service through the pico system. However, communication services over macrocellular systems are still available. Processing task 1314 then initiates processing task 1315, takes the line to answer the call and initiates processing task 1316 to begin the call through the process already described.

Referring back to FIG. 24, the handset captures the alert close command in query task 2407, and 2407 then initiates process task 2409 to turn off the alert ringer. Processing task 2409 initiates a rescan task at cordless idle entry 1420.

The responding handset stays in the close loop at query task 2125 of figure 21 waiting for the pico station's ACK. A negative result from query task 2125 initiates query task 2126 which monitors for update commands directed to the handset. Once another handset contends for acknowledgement and succeeds, a positive response from query task 2126 will initiate the process base station command task at entry 2401.

A negative response from query task 2126 initiates query task 2127 to monitor whether the pico station signal strength is greater than the disconnect level. A positive response from query task 2127 closes the loop and initiates query task 2125, waiting for the pico station's ACK. Loss of pico station signaling will generate a negative response from query task 2127 and initiate process task 2128, clear the display and cancel the alert ringer. Processing task 2128 returns to the rescan task at rescan entry 1402.

Receipt of the pico station ACK in query task 2125 initiates the initiating task at cordless call entry 2204 described above.

Each unanswered handset receives an update command. Referring now to fig. 24, processing base station command query task 2416 detects a cell phone occupancy status, and a positive result from query task 2416 initiates processing task 2417. Processing task 2417 displays the cell phone occupancy message on the display screen and initiates query task 2418 to monitor for new commands from the pico station. Similarly, a positive response from query task 2422 initiates process task 2424 to display a line seizure message on the display screen. A positive response from query task 2423 initiates process task 2425 to display an idle message on the display screen. After task 2424 or 2425, program control proceeds to task 2418 to monitor for new commands from the pico station.

A negative result from query task 2418 initiates query task 2419 to monitor whether the pico station signal strength is above the disconnect level. A positive response from query task 2419 returns to query task 2418, detecting the pico station command. All handsets will remain on this channel while the active handset is in the call.

Once the handset has lost the signal from the pico station from query task 2419, a negative result initiates process task 2420, clearing the display and returning control to the rescan task at entry 1402.

Receipt of the new command from the pico station will produce a positive result of query task 2418, initiating the process base station command task at entry 2401.

This sequence completes the call processing flow for the handset and pico station.

Two-in-one line selection module

The alternative line selection module comprises a modified cellular telephone located in an externally mountable ac powered accessory having an internal battery backup. Modifications to this cellular telephone unit include added switchable PSTN telephone line interfaces, added software to allow remote programming system compatibility, and other user operated software.

The purpose of the alternative line selection module is to provide flexible access for call service distribution. This functionality may be limited to an interoffice switching bearer (IXC) or extended to a local switching bearer (LEC). This function is referred to herein as the contention access option.

The alternative line selection module is a stand-alone device that may or may not be used with pico-stations or dual-mode handsets. The alternative line is selected as an rf link to the customer site which provides alternative access to the PSTN via the local cellular carrier device.

The two alternative line selection modules operate under the control of a local cellular carrier. It monitors calls originating from the premises and selectively routes the calls to the cellular system to complete the call. The two-one line selectively monitors the macrocellular network and is capable of routing calls placed on the two-one line selected MIN to the premises line to complete the call. The selection process, line replacement functions and modes of operation are downloaded from the cellular carrier to the alternative line selection through the remote programming capability described previously. The use of remote programming lines ensures absolute control of the two-to-one line selection module by the cellular carrier.

In the illustrated embodiment, the PSTN central office line is routed to a premises terminal at the input of a standard Network Interface Device (NID) provided by the local switching carrier. The output of the interface module is connected to the house wiring. The house line connects all the customer's telephone equipment (extensions, fax machines, computer modems, cordless phones, etc.) to the central office line. The two-one line select module is installed by connecting its input to the output of the NID. The house wiring is then connected to the output of the alternate wiring module. This connects the two-one line selection house lines in series.

This method of interconnection allows the alternative line selection module to become a replacement for the central office during which the alternative line selection actively provides competitive access from the cellular carrier to the premises.

Referring now to fig. 25, the initialization function and the remote programming operation of the two-alternative line selection module will be described.

Upon power up, task 2501 is initiated, executing internal tasks to place the telephone line interface and cellular radio in idle mode. The alternative line selection module is designed to ensure that its line interface and wireless unit fail (shut down or power down) in the on-hook state and transmitter off condition, respectively.

Task 2501 transfers control to process task 2502, which uploads the contents of the non-volatile memory to determine the operating state. Process task 2052 then initiates query task 2503 to test a programmable MIN.

If the MIN is not programmed, the two-wire selection module will attempt to place a cellular call to a factory programmed number 1-800 host until contact is established with the host.

This attempt is made on the strongest cellular bearer access channel (side a or side B) that initially serves both line selection modules. If the call is not accepted by the bearer to complete the call, the two-alternative line selection module will switch between the two sides and try the call again. If the host is busy and cannot handle the two-one line selection call, the two-one line selection module will retry at five minute intervals until a connection is established.

A negative result from query task 2503 initializes process task 2509, which turns on the status light to red, indicating that the two-out line selection is invalid. Processing task 2509 then selects a B-side system and initializes control to query task 2510, monitoring available cellular traffic.

A positive result from query task 2510 initiates a process task 2512, initiating a call to the 1-800 number assigned to the host. Query task 2513 is then initiated to determine if the call is accepted by the selected system. The cellular carrier using the two-to-one line selection module programs its switch to accept calls to remotely programmed numbers without requiring the calling unit to have a valid MIN. If the result of query task 2513 is negative or if the result from query task 2510 is negative, an initialization process task 2511 forces the two-alternative line selection module to switch to the other cellular system.

Processing task 2511 then returns to query task 2510, again testing for available traffic. An affirmative result from query task 2513 initiates query task 2514 of determining whether the host accepts calls from the two-alternative line selection module.

If the host does not answer, a negative result of query task 2514 initiates processing task 2534, enters a five minute delay, and then returns to query task 2510 to attempt contact with the host again.

A positive result from query task 2514 initiates a process task 2515 that results in a download from the host including the MIN, SID, current date/time set for the real time clock, host registration date/time window and operating parameter pattern for the alternate line selection.

The operating parameter modes of the two-alternative line selection module include a local exchange option (LEC bypass) instruction and an inter-exchange option (IXC bypass) instruction. These parameters are stored in the central processing non-volatile memory.

Processing task 2515 then connects to query task 2516, monitoring for completion of the host download. If the download process fails, a negative result of query task 2516 initializes process task 2534, performs a delay and retries.

An affirmative result of query task 2516 initiates a process task 2517 to return the status lights to a stable green state, indicating that the two-alternative line selection module is now programmed and operational. The status LED is provided as a business tool to aid in failure diagnosis when needed.

Processing task 2517 rolls back to the main traffic loop for two-out-of-line selection, check window entry at 2505.

When any power-on reset event occurs after the remote programming system downloads, a positive result from query task 2503 initiates query task 2504 to test whether the internal real-time clock is working properly. An affirmative result of query task 2504 falls back to the main service cycle entry check window at 2505.

A negative result from query task 2504 initiates a direct process to contact the remote programming system calibration time of day. This is accomplished by initiating query task 2524 to test the availability of cellular service. If the service is available, an affirmative result from query task 2524 initiates a process task 2525 to initiate a call to the host. Processing task 2525 initiates query task 2526, monitoring for responses from the host. A negative result from query task 2526 initializes process task 2529, resulting in a one minute delay, and then returns to process task 2525 for retries.

The reply from the host provides a positive result from query task 2526, initiating process task 2527. Processing task 2527 gets a real-time clock update from the remote programming system. Control then passes to query task 2528 to determine that the load was successful. A negative result of query task 2528 returns to processing task 2529. An affirmative result of query task 2528 falls back to the main business loop at 2505, checking the window entry.

Once query task 2524 determines that no services are available, its negative result initializes process task 2535, illuminates the status LED to a steady red color, and records the alarm status into non-volatile memory to allow reporting of the event to a remote programming system. Processing task 2535 then initiates query task 2536 to continue monitoring the availability of cellular traffic.

If the service is not available, query task 2536 remains in close circulation by returning a negative result to the beginning of query task 2536. A positive result from query task 2536 initiates process task 2537, restores the status light to a stable green color and returns to process task 2525, attempting to contact the host.

The check window task entry at 2505 initiates a query task 2506 following standard cellular protocols, as previously described, in several process steps to determine whether cellular service is available at the alternate route selection location corresponding to the cellular bearer SID downloaded from the host.

A negative result from query task 2506 connects process task 2530, lights the status light to a steady red color, indicates an alarm state and logs the event into non-volatile memory for later reporting to the host. Processing task 2530 initiates query task 2531, which remains in tight loop to monitor service availability. A negative result of query task 2531 returns the beginning of query task 2531. Once the traffic is available, a positive result from query task 2531 initiates process task 2532, restoring the status LED to a stable green status and returning to the check window task entry at 2505.

A positive result output of query task 2506 initializes query task 2507 when services are available. The two-to-one line selection module maintains a real time clock and a calendar to determine when its operating window is allowed and when the host should be contacted for possible updates of operating parameters. Query task 2507 tests the current date/time for comparison to the remote programming calls stored in the window. An affirmative result of query task 2507 launches query task 2533 if the incoming call window is open.

Query task 2533 determines a delayed timer condition, and a negative result of query task 2533 initiates query task 2518, monitoring traffic availability. A negative result from query task 2518 returns a check window entry at 2505.

An affirmative result of query task 2518 initiates a process task 2519 to initiate a call to the host. Processing task 2519 initializes query task 2520, testing for a response from the host. Once query task 2520 does not determine that the remote programming system is answered, a negative exit will initiate processing task 2523, starting the delay timer with a 30 second timeout value. Processing task 2523 then returns to the check window entry at 2505.

If the reply from the host produces a positive result to query task 2520, then process task 2521 is initiated to obtain an update from the host. Processing task 2521 initiates query task 2522 to determine the successful completion of the update.

A negative result from query task 2522 initializes the delay timer processing task at 2523, while a positive result returns the check window entry at 2505.

A negative result of query task 2507 initializes query task 2508 if the host call in the window is closed. A positive result of query task 2533 also initiates query task 2508. Query task 2508 compares the current date/time to the value downloaded from the remote programming system to determine if the two-alternative route selection module service window is open. The existence of such traffic windows allows the cellular carrier to conduct traffic management during periods when the cellular system has limited capacity to handle house call traffic.

If query task 2508 determines that the business window is closed, a negative result returns to the check window entry at 2505. If the business window is open, an affirmative result of query task 2508 initiates a two-alternative-line-selection online task at entry 2601.

Thus, when the service window is closed or the two-one line selection does not receive service from the cellular system, the two-one line selection module will ignore the activity of all lines in the premises.

Referring now to fig. 26, the two-alternative line selection service function will be described in more detail. The two-wire selection radio receives traffic from the cellular system when the operating window permits. A two-alternative line selection online task is entered at 2601, initiating a query task 2602, monitoring line current to determine an off-hook indication. A positive result of query task 2602 initiates query task 2603, testing the real time clock for the start of the new one minute.

To ensure coverage of all time sensitive events, if the two-way select online task finds line occupancy at the beginning of its business window, query task 2603 exits the two-way select online task and returns to the check window entry at 2505 at the beginning of each new minute. A negative result of query task 2603 returns to the beginning of query task 2602 and continues monitoring the line state.

A negative result of query task 2602 initializes query task 2604 when the line is idle, monitoring two-alternative line selection configuration data to determine a local exchange corporate bypass mode condition. An affirmative result of query task 2604 initiates a process task 2605 that activates a line transfer mechanism.

Processing task 2605 removes the premise line from the central office and replaces the full central office function with a two-to-one line selection module. Processing task 2605 and a negative result of query task 2604 both initiate query task 2606.

Query task 2606 monitors the house line to determine if an extension is off-hook. An affirmative result of query task 2606 initiates query task 2622 to monitor LEC bypass mode. A positive result of query task 2622 initiates a process task 2623 to generate an accurate dial tone to the premises wiring.

Negative results of process task 2623 and query task 2622 initiate process task 2624, capture the first dialed digit, and pass control to query task 2625.

Query 2625 determines an LEC bypass mode condition and a positive result initiates process task 2626 to remove the dial tone signal. The negative results of processing task 2626 and query task 2625 initiate query task 2627 to determine whether the first number is a one or a zero. Both cases yield one access investigation.

Once query task 2627 produces a negative result, query task 2628 is initiated to monitor for LEC bypass mode conditions. If the alternative line is selected in the IXC bypass mode, a negative result of query task 2628 initializes process task 2629 to capture the dialed exchange code (the first three digits). Processing task 2629 then initiates query task 2630 to determine whether the exchange code (NNX) is a number in a series of exchanges to be ported to a cellular carrier for completing the call. A negative result of query task 2630 returns a check window entry at 2505.

An affirmative result of query task 2630 and an affirmative result of query task 2628 initiate a processing task 2631 that captures the complete dialed number. Processing task 2631 then initiates query task 2632 to test LEC bypass mode. A negative result of query task 2632 initiates a process task 2633 to take the line from the central office and efficiently forward the call to the PSTN. The house is now connected to the two-out line selection module output interface, keeping the line powered by the-48 vdc call battery. Affirmative results of processing task 2633 and query task 2632 initiate processing task 2634 to place a cellular call to the collected dialed number.

Processing task 2634 connects the premises line audio line so that the caller can hear the line detection provided in response to the call origination. Processing task 2634 then initiates query task 2635 to monitor for call events. Control remains at query task 2635 until a call teardown event by returning an affirmative result to query task 2635 to the beginning of query task 2635. Occurrence of a disconnect event produces a negative result of query task 2635 and initiates processing task 2636.

Processing task 2636 stops the call initiated by the two-alternative line selection and releases it if the premises line is taken. The two-out-of-line selection online task then returns to the check window entry 2505. The call forwarded by the two-to-one line selection module will be completed before the two-to-one line selection window is closed.

If query task 2606 produces a negative result based on the condition of the extension, query task 2607 is initiated to monitor the receipt of incoming calls directed to the two-alternative-line-selection MIN from the cellular carrier. An affirmative result of query task 2607 initiates query task 2608 to determine if the two-one line selection MIN call is an IXC bypass event to be forwarded to the house line.

If query task 2608 results in a negative, process task 2609 is initiated to answer the two-one line selection MIN call and answer the host access protocol. Processing task 2609 initiates query task 2610 to determine whether the remote programming system is a caller. A negative result of query task 2610 initiates process task 2611, stopping the two-one line selection MIN call and returning control to check window entry 2505.

Once the result of query task 2610 is positive, process task 2612 is initiated, the remote programming system update session is captured and process task 2613 is initiated, the two-line selection MIN call is torn down and returned to verification window entry 2505.

If the IXC bypass is active, query task 2608 turns out to be positive and initiates process task 2617, seizing the house line and generating a ringing voltage to alert the extension to an incoming call. Processing task 2617 then initiates query task 2618 to monitor to determine if a response from the extension has been generated.

A negative result from query task 2618 initiates query task 2619 to monitor for continued presence of the cellular caller. A negative result from query task 2619 exits through processing task 2613 described above. An affirmative result of query task 2617 returns a ring generation processing task 2617.

The reply from the extension produces a positive result to query task 2618, initializing process task 2620. Processing task 2620 connects the house line audio to the cellular radio communication to allow the call. Processing task 2620 then initiates a query task 2621 to monitor the call. Query task 2621 will remain in a tight loop until a disconnect event occurs. An affirmative result of query task 2621 returns an input of query task 2621.

A negative result of query task 2621 initiates process task 2613, described previously, when a disconnect event occurs.

If the two-one line selection MIN does not receive a call, a negative result of query task 2607 initiates query task 2614 to monitor the central office line for a ringing voltage. A negative result of query task 2614 returns control to check window entry 2505.

An affirmative result of query task 2514 initiates query task 2615 to monitor the house line for an answer from an extension. A negative result of query task 2615 returns to the beginning of query task 2614, which continues to monitor line ringing.

A positive result of query task 2615 initiates query task 2616, which monitors answered calls for a disconnect event. If the call is still active, an affirmative result of query task 2616 returns to the beginning of query task 2616 in a tight loop. When the call is completed, a negative result of query task 2616 returns control to check window entry 2505.

During call forwarding for the two-one line selection module when the two-one line selection module is not operating in the LEC bypass mode, call activity query tasks 2635 and 2621 use the two-one line selection input line interface to monitor whether a ringing voltage is present on the central office line. Once a call to the premises occurs, the two-alternative line selection will sound a call waiting tone to the premises side of the output line interface.

The subscriber of the house line extension can choose to answer the call by performing a quick make and break. A detection of a fast on-off response to a two-to-one line selective call waiting prompt by the two-to-one line selection will cause the two-to-one line selection to switch its output line interface back to the central office line in order to answer the incoming call.

The cellular call is placed and the house line effectively suspends the called party waiting for the next fast make-and-break. If the caller forgets to return to the suspended cellular call, simply hangs up the extension, the two-line option will seize the output line interface and generate a ringing voltage to the premises line.

When this ringing is answered, the two-alternative line selection module reconnects the cellular call to the premises line. Once the cellular called party ends while on hold, the alternative line selection module will ignore any other fast make and break from the premises line.

The alternative line selection module detects an unsolicited fast make/break while the alternative line selection completes the call and is transferring to the cellular system to follow the cellular protocol.

When the two-wire select module mode of operation is a dedicated LEC update, the two-wire select line interface is always occupied (connected to the house line) and never released. All incoming or outgoing communications will be handled by the alternative line selection module and the cellular system.

The use of the described system by the customer is extremely simple and offers a number of advantages. In a purchase service, a customer may choose to support each of 6 handsets on up to three pico stations. Thus, various pico station layouts are possible, i.e. home and office, for private handsets required in the home domain.

The steps of client activation are simple and may simply include inserting the pico station, placing each handset in close proximity, selecting a handset activation command and pressing an activation button on the base station.

After registration, the use of the handset is virtually similar to a standard wired handset, in that a dial tone is generated whenever the handset is turned on, goes off-hook. Thereafter, a standard wireless dialing protocol is used.

Special handsets, one for each family member, include a select number and an optional ringing function, which, when used in conjunction with the call forwarding function of the present system, enable each family member to identify and answer personal calls directed to their private number at home.

The display feature of the handset always allows the customer to know the level of service being used, even allowing the customer to know how many home phones are registered when entering the home area.

Another feature regulates the power usage of the handset, conserves battery power as much as possible, and provides a system with minimal splatter and minimal eavesdropping risk.

Another feature is that the cellular system may be used to provide a dedicated second line for call origination when the pico station is serving another handset in the home area. Obviously, the client can also benefit directly from various service schemes, so that the charging can meet special requirements.

From a system perspective, the preferred embodiment of the present invention provides a multi-mode personal wireless communication system that integrates and co-exists in a wireless telephony network, such as a cellular network. This system provides both standard and unique additional services to select a group of customers to configure a particular handset without affecting other customers supported by the network or cellular system. The coexistence of the system is established by using a reverse control protocol level on a minimum number of reserved cellular channels that are shared by all selected groups of clients in a particular enhanced cordless mode of operation. The integration of the system is provided by strict adherence to established protocol standards without the need for frequency scheme coordination. In addition, the present invention provides for the use of special standard overhead messages with programmable content input cellular systems.

This allows the provider of cellular services to market the service efficiently in the form of a coverage area that is most attractive to customers. These areas may be as small as one cell site or up to the entire system. Thus, the customer may now purchase a form of service that provides local usage billing in the area of interest and additional usage billing in other areas. Existing cellular client devices will ignore the additional overhead messages and continue to obtain cellular service.

The special handset of the present invention automatically switches between and operates in either analog or digital mode of a standard cellular network according to existing standard protocols. When in range of a separate, locally interconnected picocell, a particular handset uses a particular protocol in the enhanced cordless mode. In keeping with the objectives required for ubiquitous telecommunications systems, the present invention provides handsets that can use the cellular network as a dedicated second line for call origination when the handset is within the associated picocellular coverage area.

The particular location analysis methods of the present invention, implemented by these handsets, prohibit them from attempting to communicate with the relevant picocells until they are within close proximity to the appropriate location. This conserves battery power and greatly reduces unnecessary transmissions on the reserved channel. Controlling such transmissions enhances the effectiveness of these channels to carry call traffic.

In addition, the incorporation of internal accurate dial tones in these particular handsets and the use of dial analysis according to the north american numbering plan provides the customer with a very user friendly and easy to use handset. The special mobile phone message display screen of the invention also increases the user friendliness of the system, and is embodied in that: the customer has always the ability to know what portion of the system is providing service and what the relative cost is, home-local-foreign.

In addition, the present invention adds an excellent ring-level feature to the call forwarding level feature, allowing the customer to quickly identify at the picocell location that an incoming or outgoing call belongs to a particular one of the supported special handsets. This can be accomplished by connecting all telephones to the house line that rings with the ring signal tone of the desired handset. The present invention also provides economic benefits to service providers in having the ability for a particular handset to be remotely programmed via a particular protocol. This capability allows for the distribution of special handsets through sales channels that are currently unavailable to service providers, further reducing the ultimate cost to the customer. In addition, the present invention provides the ability for these particular handsets to identify and operate with up to three separate picocells, providing the flexibility for the customer to set up multiple local system environments. With the addition of additional location, call traffic can be offloaded from the cellular network, and the service provider benefits from this. This offloading of traffic will allow current cellular networks to implement the present invention with minimal impact on the existing customer base.

The present invention provides transparent picocells to the network that are activated and controlled by an overlapping cellular structure that operates independently of the cellular network. As explained earlier, this overlapping structure uses a special control protocol on the reserved channel with the usage class reserved for the cell.

This particular control method does not require the picocells to contact, communicate with, or be part of the overall cellular network, allowing their operation to be transparent to the existing customer base supported by the cellular network. The present invention requires that each picocell be comprised of a spectrum-dynamic, non-acquisition, frequency-sensitive, multi-purpose base station that a customer can establish at a selected location. Each picocell operates with an overlapping cellular structure and supports an enhanced cordless mode of operation for a particular handset. Each picocell is capable of supporting multiple handsets and forming an independent, locally interconnected, coverage limited wireless communication system, efficiently downloading communication services from the cellular system. Each picocell achieves this by virtue of the local interconnection to the PSTN without the cellular network having to independently handle its registered special handset call communications.

In addition, however, as cellular network communication capacity increases, a component of the present invention, referred to as a two-alternative line selection module, may provide wireless local interconnect capability. The two-alternative line selection module is remotely programmed and allows the cellular service provider to selectively forward or distribute call communications from the public switched telephone network to the cellular radiotelephone network and from the cellular radiotelephone network to the public switched telephone network, if desired, resulting in an overall radio system.

This two-one line selection module includes within its programmable operating criteria the data necessary to internally determine when it will operate and what specific function will be performed.

As provided in the present invention, the alternative line selection module can be used independently of other components as an adjunct to existing cellular networks. This component is a valid alternative for the intelligent central office when activated in feeding the house line. This capability provides an alternative to wireless interconnections and remains fully compatible with existing equipment currently connected to house wiring, enabling cellular service providers to compete effectively on the local switching market.

The present invention also provides a service control unit and host station that facilitates wireless activation and control of each picocell and particular handset through the overlapping cellular structure. These components of the system ensure the integrity of each assembly, reducing the amount of labor previously required. The method of integrating with existing customer activation systems and the security protocol greatly reduces the chance of erroneous operation.

The present invention provides the ability to combine with remote programming systems to eliminate the need for data modem hardware at the end devices (picocells and handsets). This simplification in hardware, coupled with the increased speed of operation due to the improved data rate provided by the 10kbit channel, results in an economical and viable remote programming process.

Claims (23)

1. An RF link module providing wireless communication services to a consumer telephone device connected to the RF link module by a consumer premises line, the RF link module comprising:

a processor unit used for automatically deciding whether to program an identification number into the RF link module;

a radio frequency transmitter and receiver connected to the processor unit and configured with the processor unit for automatically obtaining programming parameters from a remote programming system via wireless communication in response to the processor determining that the identification number is not programmed, the programming parameters configured as an identification number; and

and the telephone line interface module is connected with the radio frequency transmitter and the radio frequency receiver.

2. The RF link module of claim 1 further comprising:

a ring voltage generator coupled to said processor unit and to said telephone line interface module and configured, with said processor unit, to apply a ring signal to said consumer telephone device over said line in response to detection of an incoming call associated with said identification number; and

a telephone line interface module configured to receive a telephone line from a consumer telephone device, the telephone line interface module configured to interface with the processor unit and the telephone line interface module.

3. The RF link module of claim 2 further comprising:

a dial tone generator coupled to the processor unit and the telephone line interface module and configured with the processor unit to provide dial tones to the consumer telephone device over the line when the consumer telephone device is off-hook;

wherein the processor unit is further configured to capture a first digit dialed at the consumer telephone device, clear the dial tone in response to capturing the first digit, then capture a full telephone number dialed at the consumer telephone device, and initiate a wireless telephone call using the captured telephone number.

4. The RF link module of claim 1, wherein said processor unit, said radio frequency transmitter and receiver are configured for obtaining said programming parameters from said remote programming system via said wireless communication by initiating a radio frequency telephone call to a predetermined telephone number.

5. The RF link module of claim 1 wherein:

the programming parameter is one of a plurality of programming parameters; and

the programming parameters include a system identification number SID.

6. The RF link module of claim 5, wherein:

the RF link module further includes a status indicator coupled to the processor unit; and

the processor unit is configured to determine whether communication traffic matching the SID is available, and to cause the indicator to indicate an alarm state when no communication traffic matching the SID is available.

7. The RF link module of claim 6, wherein said processor unit is configured to record said alarm state for subsequent reporting.

8. The RF link module of claim 1 wherein:

the RF link module further comprises a real-time clock;

the programming parameter is one of a plurality of programming parameters; and

the programming parameters include a current date and time setting of the real-time clock.

9. The RF link module of claim 8, wherein said processor unit is configured to determine whether said real time clock is operating properly and initiate a communication session to participate in a remote programming session providing real time clock updates when said real time clock is not operating properly.

10. The RF link module of claim 1 wherein:

the RF link module further includes a status indicator coupled to the processor unit; and

the processor unit is configured to repeatedly decide whether a wireless service is available; and causing the status indicator to indicate an alarm status when no wireless service is available.

11. The RF link module of claim 10 wherein said processor unit is configured to record said alarm condition for subsequent reporting.

12. The RF link module of claim 1 wherein said identification number is a mobile identification number MIN.

13. The RF link module of claim 1 further comprising:

a dial tone generator coupled to the processor unit and the telephone line interface module and configured with the processor unit to provide dial tones to the consumer telephone device over the line when the consumer telephone device is off-hook;

wherein the processor unit is further configured to capture a first digit dialed at the consumer telephone device, clear the dial tone in response to capturing the first dialed digit, then capture a full telephone number dialed at the consumer telephone device, and initiate a wireless telephone call using the captured telephone number.

14. An alternate line selection ALO module for providing wireless telephony services to a consumer telephony device connected to the ALO module by a consumer premises line, the ALO module comprising:

a processor unit for deciding whether a mobile identification number MIN is programmed into the ALO module;

a radio frequency transmitter and receiver coupled to the processor unit and configured with the processor unit to obtain activation parameters from a remote programming system via wireless communication when the MIN is not programmed, the activation parameters including the MIN;

a telephone line interface module;

a ring voltage generator coupled to the processor unit and the telephone line interface module and configured with the processor unit to provide a ring signal to the consumer telephone device over the line in response to detecting an incoming call for the MIN;

a telephone line interface module coupled to the processor unit and the telephone line interface module and configured to provide a predetermined DC voltage to the consumer telephone device over the telephone line; and

a dial tone generator coupled to said processor unit and said telephone line interface module and configured by said processor unit to provide a dial tone to said consumer telephone device over said line when said consumer telephone device is off-hook;

wherein the processor unit is further configured to capture a first digit dialed at the consumer telephone device, and to clear the dial tone in response to capturing the first dialed digit, then capture a full telephone number dialed at the consumer telephone device, and initiate a wireless telephone using the captured telephone number.

15. The ALO module of claim 14, wherein when the MIN is not programmed, the processor unit, the radio frequency transmitter, and the radio frequency receiver are configured to obtain the activation parameter from the remote programming system via wireless communication by initiating a radio frequency telephone call to a predetermined telephone number.

16. The ALO module of claim 15, wherein the processing unit is configured to automatically initiate a radio frequency telephone call to the predetermined telephone number upon determining that the MIN is not programmed.

17. The ALO module of claim 14, wherein said activation parameter comprises a system identification number, SID.

18. The ALO module of claim 17, wherein:

the ALO module further comprises a status indicator connected to the processor unit; and

the processor unit is configured to determine whether cellular service matching the SID obtained using the activation parameter is available when the MIN is programmed, and to cause the status indicator to indicate an alarm status when no cellular service matching the SID obtained using the activation parameter is available.

19. The ALO module of claim 18, wherein said processor unit is configured to record said alarm state for subsequent reporting.

20. The ALO module of claim 14, wherein:

the ALO module also comprises a real-time clock; and

the activation parameters include a current date and time setting of the real-time clock.

21. The ALO module of claim 20, wherein said processor unit is configured to determine whether said real-time clock is operating properly; and initiating a radio frequency telephone call to a remote programming session that provides real time clock updates when the real time clock is not operating properly.

22. The ALO module of claim 14, wherein:

the ALO module further comprises a status indicator coupled to the processor unit; and

the processor unit is configured to repeatedly decide whether a wireless service is available; and causing the status indicator to indicate an alert status when no cellular service is available.

23. The ALO module of claim 22, wherein said processor unit is configured to record said alarm state for subsequent reporting.