KR960012088B1 - Cellular Cordless Cordless Telephone Device and Operation Method - Google Patents

Abstract

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Description

Cellular Cordless Cordless Telephone Device and Operation Method

[Brief Description of Drawings]

1 is a block diagram of the operational configuration of a portable radiotelephone in which several systems, including both cellular and cordless systems, can be accessed by the same portable radiotelephone.

2 is a schematic map showing typical coverage areas for codeless systems, microcellular systems, and cellular systems.

3 is a block diagram of a codeless base station using the present invention.

4 is a block diagram of a portable wireless telephone employing the present invention.

5-1 and 5-2, the flowchart of the process used by the portable radiotelephone when the portable radiotelephone of FIG. 4 is not called.

6-1 are a flow chart of the process used by the wireless base station of FIG. 3 when the portable wireless telephone is not called.

6-2 is a continuation of the flow chart of FIG. 6-1 for the process used by the wireless base station of FIG. 3 when the portable radio telephone is called.

7-1 and 7-2 are flowcharts of the processing used by the portable radiotelephone when the portable radiotelephone of FIG. 4 is called.

8 is a message stream format transmitted from the wireless base station of FIG.

9 is a format diagram of a command message and a channel change message that includes part of the message flow format of FIG.

FIG. 10 is a tight diagram for the system scanning process used in the portable wireless telephone of FIG.

11-1, 11-2, and 11-3 are flowcharts of a system priority selection process used in the portable wireless telephone of FIG.

Detailed description of the invention

[Field of Invention]

FIELD OF THE INVENTION The present invention relates generally to portable telephones, and more particularly to improved portable telephones that receive calls in both cordless and cellular telephone systems.

[Background of invention]

Cordless telephone systems generally include a cordless handset and a cordless base station connected to a telephone company phone system (TELCO) by telephone communication lines. A cordless base station is assigned a telecommunication line telephone number that allows a user to be located within the limited range of a cordless base station such as a home and to receive a call using a cordless portable handset. However, due to the limited range of cordless base stations, cordless portable handsets provide users with relatively local radiotelephone communications.

Wireless telephone communication outside the scope of a cordless telephone system may also be provided to the user via a cellular telephone system. Cellular telephone systems generally include a cellular subscriber unit (mobile or portable) and a cellular base station connected to TELCO via one or more cellular switching networks. Each cellular subscriber unit is assigned a cellular telephone number that allows the user to locate and receive calls (or calls) within a wide range of cellular base stations, such as throughout a metropolitan area. However, the cost of using a cellular telephone service is much higher than the cost of using a cordless telephone service.

The problem arises for users who are frequently located between cellular cordless telephone systems. Incoming calls routed to systems where the user is not located may be missed. In the prior art, landline and cellular telephone stations have provided a solution to this problem through a feature known as No Answer Transfer or Call Forwarding or Three way Calling. An unanswered transmission allows a user to route an incoming call from a cellular telephone system to a cordless telephone system or an incoming call from a wireless telephone system to a cellular telephone system when the user's telephone is not turned on, does not answer, or is out of range of the base station. Allow the system to be programmed. Therefore, the user receives an incoming call that arrives at either a cordless or cellular telephone system.

There are several problems with the non-responsive transmission characteristic. The user must program the system manually whenever it needs to enable or disable the non-responsive transmission feature. Forgetting to program your system manually can result in not receiving an incoming call or improperly routing the incoming call. Users also have to purchase and operate special wireless telephone equipment for both cellular and cordless telephone systems, resulting in increased cost and inconvenience for the user.

In addition, cellular and cordless systems in both cases must have the ability to select which system the portable radiotelephone transmitting and receiving calls will operate in. In order to benefit the user, automatic system selection should be made for the parameters. The user should also be able to select the system manually, overriding automatic selection.

Accordingly, what is needed is a wireless telephone system that allows a user to receive incoming calls through both cellular and cordless telephone systems without incurring cost or inconvenience to the user.

[Overview of invention]

The cellular cordless telephone has a first mode of operation for generating and receiving cellular telephone calls over a cellular radio channel of a cellular telephone system, and a second mode of operation for generating and receiving cordless telephone calls on a cellular radio channel used by a wireless base station. Has The cellular cordless telephone automatically selects between the first and second modes and receives from the cellular radio channel when both the first and second modes are operating. The cellular cordless telephone transmits on the cellular radio channel with an output power supply having a predetermined set of power magnitude steps when operating in the first mode, and transmits on the cellular radio channel when operating in the second mode. Transmit on a cellular radio channel at a power level chosen so as not to be greater than the lowest power size step.

Detailed Description of the Preferred Embodiments

A generalized block diagram related to the application of the present invention is shown in FIG. The illustrated portable cellular cordless (PCC) cordless telephone 101 is capable of communicating with a conventional cellular radiotelephone system 103, which has a plurality of cellular base stations 105, 107 and each Cellular base stations are located in geographically separated locations but are intended to provide wireless telephony coverage over a wide range of areas. The cellular base station is connected to a control terminal 109, which coordinates between multiple cellular base stations, including handoffs for the user's cellular mobility and portable equipment, and is referred to as a public switched telephone network (hereinafter referred to as TELCO). Provide call switching and interconnection to (11).

PCC 101 also has the ability to communicate with microcellular base station 113, which has low power and limited capabilities as a cellular adjunct cell, but is airborne in separate areas such as shopping malls, airports, and the like. Provides cordless phone service. Since the microcellular base station 113 is connected to the TELCO 111 landline system, the call can be placed in TELCO.

PCC 101 is also capable of locating and communicating wireless telephone calls through cordless base station 115, which provides a personal telephone line that interconnects with TELCO 111 for PCC 101 users. As mentioned above, the codeless base station 115 and the PCC 101 together provide a limited codeless area service, commonly known as a codeless telephone service. Such services are widely used because they typically use several radio frequency channels in the high frequency (HF) codeless band.

Cordless phone users can use cordless telephone services wherever they travel in the United States, and they expect these services to be offered at the lowest possible cost. It is also expected that wireless telephony services will be provided in as small and inexpensive portable units as possible. PCC 101 is uniquely configured to meet this purpose. In addition, the cordless base station 115 is uniquely designed to provide a user's home telephone line and telephone connection when the user has a PCC 101 within the codeless area of the cordless base station 115.

2 shows a general configuration of a service area (effective area) in a codeless system, a microcellular system and a cellular system. The codeless system service area is the smallest and is within the microcellular system. Microcellular systems are in the midrange of coverage and are within cellular systems. The effective area of each system depends on the antenna height and power level used in each system and the number of base stations in each system and may be based on other factors. The user of the walkie-talkie is relocated between several effective areas. Portable cordless phones vary between systems based on the location of the portable cordless phone, system availability and user preferences and may be based on other factors.

The effective area of the system is not limited to the specific configuration as shown in FIG. One valid region may be independent of another valid region or may overlap one or more other valid regions.

Conceptually, the codeless base station 115 transmits outbound data messages in a form similar to a typical cellular outboun d signaling channel and receives a service request from a remote unit such as PCC 101. It is a subminiature cellular system. The appropriate service request is given an allocation of voice channels (performed via the communication channel) on the same frequency or a second codeless frequency that directs the PCC 101 to tune the telephone call.

A basic implementation of a codeless base station is shown in FIG. Conventional transmitters 301 and receivers 303 suitable for use in the frequency bands 869-894 MHz and 824-849 MHz used for conventional cellular services, respectively, are connected to a common antenna 305 via a duplexer 307. . The power output of the transmitter 301 is limited to about 6 mW to minimize interference to other services and other cordless telephone stations. The selection of the channel frequency is implemented with a frequency synthesizer 309 controlled by the logic unit 311. Within the logic unit 511 is a microprocessor 513, a 68HC11 or similar microprocessor available from Motorola, which is connected to a conventional memory device 315, which is a microprocessor operating program. It remembers base identification (BID) and personal identity and other characteristics. The received and transmitted data is encoded / decoded and connected between the receiver 303 and the transmitter 301 and the microprocessor 313 via signaling interface hardware 317. Microprocessor instructions are passed on and executed by control hardware 319. The interface with the user's home landline is usually performed via the TELCO interface 321. Power is supplied from conventional AC mains and backed up to battery reserve (all shown as power 323).

PCC 101 is a portable radiotelephone transceiver shown in block diagram in FIG. The portable wireless receiver 401 can receive a frequency band between 869 and 894 MHz, and the portable transmitter 403 can transmit at low power (about 6 mW in a preferred embodiment) on a frequency between 824 and 849 MHz. And the receiver is connected to the antenna 405 of the PCC 101 via the duplexer 407. The particular channel of radio frequency used by transmitter 403 and receiver 401 is determined by microprocessor 409 and communicated to frequency synthesizer 441 via interface circuit 413. The data signal received by the receiver 410 is decoded by the interface circuit 413 and connected to the microprocessor 409, and the data signal to be transmitted by the transmitter 403 is generated by the microprocessor 409 and the transmitter Formatted by interface 413 before being sent by 403. The operating states of the transmitter 403 and the receiver 401 are enabled or disabled by the interface 413. The interface also controls light emitting diodes 415 and 417, which diodes are used to indicate to the user which system the PCC 101 is currently receiving. The control of the user voice and the micro output and speaker input are controlled by the voice processing circuit 419.

In the preferred embodiment, the microprocessor 409 is a 68HC11 microprocessor available from Motorola Inc., and performs the necessary processing functions under program control stored in the ordinary ROM 421. The characteristics that characterize the PCC 101 are stored in the EEPROM 423 (also stored on an embedded microprocessor EEPROM), which includes the number assignment (NAM) and user required for operation in a typical cellular system. And a base identification (BID) required for operation with its own cordless base.

The transmitter 403 of the PCC 101 is capable of transmitting in accordance with the full range of output power required for operation in a typical cellular system. The output power range is comprised of six sets of output power sizes ranging from a high output power level of about 600 mW to a low output power level of 6 mW. The six sets of output power ranges are enabled when the PCC 101 is in cellular system mode.

According to a preferred embodiment of the present invention, the same PCC 101 is compatible with both cellular and cordless telephone system 103. This is done by allowing the PCC 101 to operate in both cellular and cordless telephone systems 103 using only cellular telephone frequencies.

Such a radiotelephone device has advantages that are desirable for a user. First, the PCC 101 can automatically route an incoming call with the cordless base station 115 to the telephone system where the PCC 101 is located without any inconvenience to the user. Second, if PCC 101 is located between the cordless telephone system and the cellular telephone system, the PCC 101, along with the cordless base station 115, automatically establishes an ongoing call with the PCC 101 between the cordless telephone system and the cellular telephone system. Specify the path.

5-1 and 5-2 are flow charts of the process used by PCC 101 of FIG. 6-1 is a flowchart of the process used by the codeless base station 115 in FIG. In one embodiment of the present invention, the PCC 101 and the cordless base station 115 operate cooperatively as described in the flowcharts in FIGS. 5-1, 5-2 and 6-1, respectively, Depending on the location, the incoming call is routed to the cordless telephone system or the cellular telephone system 103.

As shown in FIG. 5-1, the PCC 101 may be in an idle state in the cellular telephone system at block 501 or in an cordless system at block 503. In either idle state, the PCC 101 is capable of receiving incoming calls. For illustrative purposes, assume that PCC 101 is in idle state in cellular telephone system 103 at block 501. PCC 101 returns to idle state in cellular telephone system 103 by returning to block 501. It is determined at block 505 whether to continue or change to an cordless telephone system by scanning an acceptable codeless base station at block 507. If the scan process is determined at block 509, an acceptable codeless base station ( 115 is found, the PCC 101 sends a registration message (the PCC's attempt to register with the codeless base station) to the codeless base station 115 at block 511. If not found, the PCC 101 returns to an idle state in the cordless telephone system at block 501.

In FIG. 6-1, the codeless base station 115 normally waits in block 601 for an idle state. Upon receiving the registration message at block 603, the codeless base station 115 determines at block 607 whether the PCC 101 is acceptable. If no registration message is received at block 603, codeless base station 115 returns to an idle state at block 601. If the PCC 101 is acceptable, the codeless base station 115 transmits an acknowledgment message at block 605, transmits its own landline telephone number at block 601, and blocks Return to idle state at 601. If the PCC 101 is not accepted by the codeless base station 115 at block 607, the codeless base station 115 sends a reject message (non-registration of the PCC by the codeless base station) at block 609. And return to idle state at block 601.

In Figure 5-1, PCC 101 determines in block 513 whether an accept (PCC registration) message is received. Upon receipt of the accept message, PCC 101 receives the terrestrial telephone number of codeless base station 115 at block 515.

If no accept message is received, PCC 101 returns to idle state of the cellular telephone system itself at block 501. Therefore, the cordless base station 115 has been informed of the change decision of the PCC 101 to the cordless telephone system, and the codeless base station 115 responds by providing the PCC 101 with a terrestrial telephone number.

5-1, the PCC 101 determines at block 517 whether the user's cellular and terrestrial phone numbers have call routing priorities. Call routing priority refers to the user's system preference (cellular or landline), where the incoming call is routed first before being sent to the second system when the PCC 101 is not located. Since the user is available through both cellular and terrestrial telephone numbers, it is convenient for another party to provide only one telephone number to grant the incoming call to the user. Therefore, the other subscriber may only use a single phone number to reach the user's PCC 101 in either the cellular or cordless telephone system.

If the cellular telephone number has a call routing priority, the PCC 101 sends the cellular telephone number to the landline number of the codeless base station at block 519, and idles within the cordless telephone system at block 503. do. Therefore, the incoming call routed to the user's cellular telephone number is automatically sent to the terrestrial telephone number of the cordless base station 115 when the PCC 101 is located in the cordless telephone system.

If the user's terrestrial phone number has a call routing priority, the PCC 101 transmits, at block 521, the user's terrestrial phone number (which was sent to the cordless base station) of the cordless base station to the terrestrial phone number of the codeless base station. Send a call forward message instructing the codeless base station to wait and idle in the codeless telephone system at block 503. In FIG. 6-1, if a call transfer message is received by the codeless base station 115 at block 613, the codeless base station 11l is configured to send the user's terrestrial phone number of the codeless base station 115 at block 615. Perform remote call forwarding to the terrestrial phone number and return to idle state at block 601. Therefore, the incoming call routed to the user's terrestrial phone number is automatically transmitted to the terrestrial phone number of the cordless base station 115 when the PCC 101 is located in the cordless system. Even if PCC 101 is turned off, the user continues to receive the incoming call through any telephone associated with the base station's telephone number.

5-2, the PCC 101 returns to block 503 to determine whether to remain idle within the cordless telephone system or to change to cellular telephone system 103 by proceeding to block 525. 523). At block 525, PCC 10 1 determines whether the cellular telephone number or user terrestrial telephone number of PCC 10l has a call routing priority. If the cellular telephone number has a call routing priority, the PCC 101 sends a cancel call forwarding message to the cellular system, and the PCC 101 idles in the cellular system at block 501. Return to wait for status. Therefore, the incoming call routed to the user's cellular telephone number directly calls the PCC 101 located in the cellular telephone system 103.

If the user's land phone number has a call routing priority, the PCC 101 calls the codeless base station 115 to transmit the cellular phone number of the PCC 101 to the user land phone number at block 531. Send a call forwarding message. If the PCC 101 cannot establish communication with the cordless base station 115, the PCC 101 may perform a call transfer by making a cellular telephone call. Thus, the incoming call routed to the user's land telephone number is transmitted to the cellular telephone number of the PCC 101 located in the cellular telephone system 103.

7-1 and 7-2 are flow charts of another process used by the PCC of FIG. 6-2 is a continuation of the flowchart of FIG. 6-1 for the process used by the codeless base station 115 of FIG. In an alternative embodiment of the present invention, the PCC 101 and the codeless base station 115 are codeless when the location of the PCC 101 is described in a flow chart in FIGS. 7-1, 7-2 and 6-2, respectively. Cooperating to automatically route (ie, hand off a call) an ongoing call between the cordless telephone system and the cellular telephone system 103 when moving out of range of the telephone system and moving into the service area of the cellular telephone system 103. do. An advantage of automatic handoff operation for the user is that the PCC 101 operation is transparent (not rollable) between the cellular and cordless telephone system while the PCC 101 is in a call state. Another advantage of automatic handoff operation for the user is the lower cost of operation of the cordless telephone service. If the PCC 101 is within the acceptable range of the cordless base station 115, the PCC 101 switches from the cellular telephone system 103 to the cordless telephone system.

As shown in FIG. 7-1, PCC 101 is in a call in either cellular telephone system 103 in block 701 or in a cordless telephone system in block 703. For purposes of explanation, assume that PCC 101 is in a call state within cellular telephone system 103 at block 701. Whether the PCC 101 will continue to the calling state in the cellular telephone system 103 by returning to block 701 or will be changed to a codeless telephone system by scanning an acceptable codeless base station 115 at block 707. Is determined at block 705. If the scan process finds an acceptable codeless base station 115 as determined at block 709, PCC 101 transmits a registration message to codeless base station 701 at block 711. If not found, PCC 101 returns to the calling state in the cordless telephone system.

In Fig. 6-1, the codeless base station 115 normally waits in an idle state at block 601. Upon receiving the registration message at block 603, the codeless base station 1115 determines at block 607 whether the PCC 101 is acceptable. If no registration message is received at block 603, codeless base station 115 returns to an idle state at block 601. If the PCC 101 is acceptable, the codeless base station 115 transmits an accept message to the PCC 101 at block 605, and transmits the base telephone number of the base station to the PCC 101 at block 611. Return to idle state at block 601. If PCC 101 is not accepted by codeless base station 115 at block 607, codeless base station 115 sends a reject message to PCC 101 at block 609 and is idle at block 601. Return to.

In Figure 7-1, the PCC 101 determines in block 713 whether an accept message is received. If an accept message is received, PCC 101 receives the terrestrial telephone number of codeless base station 115 at block 715. If not received, the PCC 101 returns to the calling state in the cellular telephone system 103 at block 701. Thus, the cordless base station 115 has been informed of the PCC 101 decision on the change to the cordless telephone system, and the codeless base station 115 responds by providing the PCC 101 with the base telephone number of the base station.

According to a preferred embodiment of the present invention, an ongoing call between a PCC 101 operating within a cellular telephone system 03 and a calling party is established at the ground of the PCC 101 and the counterpart subscriber and the codeless base station l15. The handset is handed off from cellular telephone system 103 to a cordless telephone system by making a three way call through cellular telephone system 103 between telephone numbers.

In Figure 6-2, the codeless base station 115 receives a handoff request from the cellular to the codeless system at block 617, and at block 619 to open the communication between the other subscriber and the codeless base station 115. Answer the landline leg of the three-way call. PCC 101 is now in a cordless telephone call state, which is the calling party at block 621. In Figure 7-1, PCC 101 operating in cellular telephone system 103 terminates the cellular shorting of a three-way call at block 718 to terminate cellular system communication between PCC 10l and the subscriber. Conclude. Therefore, the call in progress is handed off from the cellular telephone system 103 to the cordless telephone system when the PCC 101 relocates from the cellular telephone system 103 to the cordless telephone system.

In Figure 7-2, the PCC 101 continues to remain in a call state within the codeless telephone system by returning to block 703 or whether to change to a cellular telephone system by proceeding to block 725. Decide on). In block 725, the PCC 101 operation in the cordless telephone system causes the codeless base station 115 to generate a three-way call between the party subscriber and the user's telephone number and the PCC 101 so that the cellular telephone system ( 103) to perform the handoff.

In Figure 6-2, the codeless base station determines, at block 623, whether a request from PCC 101 is received to hand off from the codeless system to the cellular telephone system 103. When the request is received at block 623, the codeless base station makes a three-way call between the landline number of the codeless base station 115 and the party subscriber and the PCC 101 operating at the cellular telephone system 103 at block 625. Perform. If the request is not received, the codeless base station 115 returns to block 621 and remains in the calling state within the codeless telephone system. In Figure 7-2, the PCC 101 responds to the cellular shorting of the three-way call at block 722 to open communication between the PCC 101 operating on the cellular telephone system 103 and the other subscriber. Therefore, PCC 101 is now in a cellular telephone call state at block 701. In Figure 6-2, the codeless base station 115 terminates the ground short of the three-way call at block 627 to terminate communication between the originating subscriber and the codeless base station l15, and is idle at block 601. Return to the state.

Determining a change between the cellular and cordless telephone system at blocks 505,523,705,723 is based on various factors such as user's manually determined preferences, automatic system scanning preferences or codeless received signal characteristics and is not limited to these factors. The PCC 101 also accepts the PCC 101 at blocks 509 and 709 and scans a number of codeless base stations 1115 that are known to be possible.

So far, two embodiments of the present invention have been described. In a first embodiment, a radiotelephone arrangement is described that allows incoming calls to be routed to a PCC 101 located in a cellular or cordless telephone system. In another embodiment, a wireless telephone apparatus is described that can handoff an ongoing call with PCC 101 between a cellular system and a cordless telephone system when the P CC 101 is repositioned between the cellular and cordless telephone system. The wireless telephone device includes two embodiments of the present invention.

When the two embodiments are combined, there are some moments in which the call transfer must be changed or canceled before the three-way call is established. In one embodiment, the user's land phone number has a call routing designation priority. PCC 101 is present in the cellular telephone call, and PCC 101 determines the change to the cordless base station 115 connected to the user's land telephone number. The call transmission of the user's land telephone number must be canceled before the three-way call is located to include the cordless base station 115. In another embodiment, the user's cellular telephone number has a call routing priority. PCC 101 is in a cordless telephone call state, and PCC 101 determines the change to cellular telephone system 103. Call transfer on the user's cellular telephone number must be canceled before the three-way call is placed to include the cellular telephone system 103. In addition, the routing of the call may be updated at the end of the ongoing call. Thus, a single PCC 101 operates ubiquitously in cellular and cordless telephone systems.

The wireless telephone device described above is not limited to cellular and cordless telephone systems. The telephone apparatus described above can operate in at least two wireless telephone systems and it is preferred that the PCC 101 is switched between these systems. The reasons why this is desirable include, but are not limited to, service areas, service costs or service characteristics.

Since at least two systems (usually cellular systems and codeless systems) have mutually overlapping radio coverage areas, it is important to establish a priority hierarchy. Cordless systems are expected to be less costly than conventional cellular systems because they are connected to the TELCO public switched telephone network via a landline at the user's home. The codeless system would be a good system if the PCC 101 is within the effective area of the codeless base station 115. Therefore, in the preferred embodiment, priority is given to the service of the codeless base station. However, the user may select another priority hierarchy if desired.

The cordless base station 115 transmits an outbound signaling message on the radio channel selected to not interfere with the radio channel used within the local cellular system 103. The message indicates the identity of the codeless system and is similar to the message sent in a conventional system in that the PCC 101 is intended to help determine system availability. The format of the message from the codeless base station on the signal channel is shown in FIG. The information is transmitted in NRZ format and contains 20 bits of Synchronized Data Bits (SYNCA) followed by a 30-bit Message Word (including 1/4 of the entire 120 NRZ bits), followed by 18 bits of Synchronized Data Bits ( SYNCB) followed by a 30 bit message word followed by a 30 bit message word. The format continues for four word segments to be transmitted. In a preferred embodiment, successive transmissions to the next message word are followed by a fourth quarter message word with SYNCA synchronization. An alternative embodiment provides a break between the message words and the synchronization bits inserted between them, making signal channel transmissions discontinuous.

Two examples of the format for the message word are shown in FIG. Each message word is sent in Manchester format. Since the Manchester bit has two NRZ bits with opposite states, 60 Manchester message bits are encoded into 120 NRZ bits. An example of the first message word is an order message, which is a 32-bit Base IDentification (BID) field 901, a call status field 903, a command field 905, a command formula field 907. ), A field 909 reserved for future use and a Parity Check field 911. An example of a second message word format is a channel change (handoff) message that also includes 60 bits. The message word also starts in the known field 913 field, starting with the call status 915, command 917, go-to-channel indication 919 and 12-bit parity 921. Include. Each word message contains a known field at the beginning, which operates in a manner similar to the conventional system identification (SID) used in cellular systems. However, BIDs include 32 bits rather than 15 bits in cellular systems. The BID is programmed into the codeless base station memory 315 as a unique number for each codeless base station. Since the unique BID provides a special characteristic for each codeless base station, the user's PCC 101 and codeless base station 115 operate together without allowing unauthorized user access.

In the preferred embodiment, two bits of the call status field are specified as follows. That is, 0 is an idle state in which no initialization is allowed in the codeless base station, 1 is an idle state in which initialization is allowed, 10 is a ringing state, and 11 is a conversation state. The 2-bit command field conveys: That is, 0 is an extended command and 1 is a channel change or handoff. The command identification field of the command message word is defined as follows. That is, 0 is overhead and 1 sends the called address. The two synchronization fields used in the preferred embodiment are SYNCD = 0100 1001 0101 0110 1101 and SYNCB = 01 0010 0110 1101. Of course, other forms of synchronization may be used as long as appropriate cross-correlation properties are provided.

For better stability and interference avoidance, BIDs with command message words are transmitted subaudibly continuously on the voice channel. The PCC 101 receives and decodes the BID and checks for a match between the BID transmitted below the audible value and the codeless base station 115 BID associated with it. As long as the BIDs match, the conversation on the voice channel continues. As soon as a mismatch is detected, the voice received by the PCC 101 is muted and the transmitter 403 of the PCC is unkeyed. After the PCC 10 receives an inadequate BID for a predetermined period and after a lack of receive transmission that continues from the PCC 101 to the codeless base station 115, the call ends.

For the case where the priority set for the PCC 101 is the PCC base station 115 is the first predetermined path for the user's telephone call, and the typical cellular (or microcell system) is the second choice, the priority The process of implementing the ranking is shown in FIG. Fig. 10 shows that a PCC receiver 401 of an outward signal channel over time receives an outward signal channel or signal channel set transmitted from a cellular system, a cordless base station and a microcellular system. The diagram illustrates the unique scanning priority characteristics of the present invention.

It helps.

The PCC receiver 401 may monitor 1001 the outbound message stream sent from the cellular telephone system signal channel (selected in a conventional manner among a plurality of cellular signal channels). At the appropriate time, the microprocessor 409 instructs the PCC receiver 401 to tune to one of the frequencies or frequencies in use by the codeless base station 115.

PCC 401 scans 1003 the codeless known outbound signal channel or channels for a certain time period t ₂ . If the signal data stream is not received in sufficient quantity, the PCC receiver 401 returns to the previously selected signal channel of the cellular system 103. The PCC receiver 401 continues to tune to the signal channel 1005 for a period of time t ₁ before attempting another scan of one signal channel of the other system. The relationship between t ₁ and t ₂ is such that the cellular page message (i.e., codeless telephone call or other transmitted requirement) that is typically repeated after a five second pause is not missed, which causes the PCC receiver 401 to be cellular. This is because other systems are being scanned during the page transfer time. The time t ₁ must be greater than the sum of the idle period between the two pages and the time normally required to transfer the two pages. Time t ₂ must be less than the time between two pages. If the idle period is 5 seconds and the time to send one page is typically 185.2 msec, then t ₁ must be greater than 5.3704 and t ₂ must be less than 5 seconds. After monitoring the cellular system signal channel for t ₁ hour, the PCC receiver 401 is instructed to tune to the signal channel or continuous signal channels of the micro cell system as shown at 1007. If no suitable micro cell signal channel is found during the scan of a given signal channel frequency, the PCC receiver 401 returns to the cellular system signal channel as shown at 1009.

Scanning the signal channel 1011 of the codeless base station 115 and finding a signal data stream that satisfies the appropriate quality requirements will result in the PCC receiver 401 continuing to monitor the codeless signal channel. The PCC receiver 401 remains in the codeless signal channel without rescanning another system until the PCC 101 cannot receive the signal transmitted by the PCC base station for five consecutive seconds.

The effect of the priority process is to give priority to the codeless base station 115 at the PCC 101.

Once the signal channel of the cordless base station 115 is developed, the PCC 101 continues to tune to that channel. Therefore, even if the PCC 101 is initially tuned to the cellular system, it is automatically switched to the codeless base station if it is accessible to the codeless base station. Once the PCC receiver 401 finds a codeless known signal channel, the PCC receiver continues to tune to that channel. When the PCC transceiver is turned on, the first scan of the signal channels becomes a preset signal channel or channels of the codeless base station 115. Of course, the user may override the automatic priority hierarchy by entering an override code into the PCC 101. In this way, the user can force scanning of the cellular system signal channel only or of the codeless known signal channel only or of the micro cellular system signal channel only or a combination of the above systems. The user can also perform a call or origination even after ignoring the system of their choice.

Once the signal channel of the system is being reduced, a visual indication is provided to the user of the PCC transceiver. In the preferred embodiment, the indicator is a set of light emitting diodes (LEDs) 4L5, 417, one of which uniquely emits light to indicate the system to which the PCC transceiver is tuned. Different indicators are used alternately to convey the same information. For example, a flashing symbol (with different flash speeds) may be used in which the system identifier appears or flashes on the numeric display of the PCC 101. In any case, the indication allows the user to decide which system to be in and also to decide whether to complete a wireless phone call within that displayed system.

Referring now to Figures 11-1, 11-2, and 11-3, there is shown a flow chart of the process followed by the PCC 101 in implementing the stamp priorities. The process is executed by the microprocessor 409 through an operating program of the microprocessor stored in the ROM memory 421. As soon as the power is turned on at 1101, the radio sets the cellular scan counter to zero. This variable is used to prevent excessive word synchronization loss or other reasons causing excessive cellular rescanning to prevent the PCC 101 from scanning for the codeless base station 115 channel. After resetting the cellular scan counter, the predetermined signal channel (or channels) of the codeless base station 115 determines whether the received signal channel has an appropriate BID when the PCC 101 is within range of the codeless base station. Scanned at 1103 to determine whether the channel has sufficient signal quality.

PCC 101 determines at 1105 whether all of the above criteria are met. If the criterion is met, the codeless mode of operation is entered, and the user is informed at 1107 for the light emission of the LED associated with the codeless mode.

The PCC transceiver is in a mode that processes the codeless function at 1109, which includes codeless [detected at (111)] until synchronization or BID is lost between the PCC 101 transceiver and the codeless base station 115. Detecting a known signaling channel, configuring and receiving a cordless telephone call, and performing a channel change (handoff) between the PCC transceiver and the cordless base.

If synchronization or BID matching is lost, the processor moves to 1113 to detect whether the PCC 101 is involved in a wireless telephone call. If the PCC 101 is not busy, the process moves to the scanning phase of the cellular system signal channel. If the PCC 10l is busy, several attempts are made to reconnect the call to cordless mode. The codeless known scan counter is reset at 115 and it is checked at 1117 whether the counter has exceeded the maximum number of codeless known scans (maximum = 2 in a preferred embodiment). The codeless channel is scanned at 1119 as described at 1103 and the result is checked at 1121. If a signal channel from the cordless base station 115 is found, the cordless telephone call is resumed. If not found, the codeless known scan counter is incremented at 1123 and checked at 1117 to see if it exceeds the maximum.

If the codeless known stem counter exceeds the maximum, the PCC 101 will abort the codeless mode and attempt to scan the signal channel to the cellular system 103.

The cellular scan also begins at process 1125, which also enters from test 1105. First, a codeless known rescan timer is reset (set to zero) at 1125 to indicate the time of the end of the last codeless communication. Since the cellular scan is about to begin, the cellular scan counter is incremented (1 added) at 1127. PCC 101 scans the signal channel of the cellular system at 1 l29 according to typical user settings.

A test is performed at 1131 to determine whether an appropriate signal channel is present in the list of cellular signal channel frequencies scanned by the PCC 101. If no channel is acceptable, the noSVC LED is illuminated at 1133 and the process returns to scan the codeless signal channel at 1101. If the cellular system signal channel is found to be acceptable, then the LED indicating that service mode is illuminated and all other service providers' LEDs are turned off at 1135. The cellular rescan timer is reset at 1137 to determine the time when the final cellular rescan is completed. The process then proceeds to a modified cellular system idle task, which is 1138.

The idle task (1138) first determines at 1139 whether it is time to force codeless rescan. Forced codeless rescan occurs when the codeless known rescan timer is greater than the CBRT. CBRT is a codeless known rescan timeout and is set to 60 seconds in the preferred embodiment. In order for a forced codeless rescan to occur, the cellular scan counter must exceed the maximum number of consecutive cellular scans set to 6 in the preferred embodiment. If no checking is done and the radio gains a cellular channel and loses word synchronization, rescanning is enforced since the PCC 101 may not be able to exit the infinite loop. If forced codeless rescan is not needed, the PCC 101 is tested at 1141 to determine whether cellular word synchronization exists. If word synchronization does not exist, the PCC 101 rescans the cellular system by starting at 1127. Since the codeless base is not scanned, resetting the codeless base rescan timer is skipped at 1125.

If word synchronization is present, a determination is made at 1143 whether system access is needed (ie, call origination, call page response or other directed cellular system access). If system access is needed, an attempt is made at 1146 to access the cellular system in a conventional manner. Successful access results in a post power on returning to the process. A failed access, such as the case of receiving a page request but not a successful response attempt, results in a return to the cellular system signal channel scan as determined at 1148.

If it is determined at 1143 that no system access is needed, then a test is performed at 1145 to determine whether cellular rescan should occur. Cellular rescan occurs when the cellular rescan timer exceeds 300 seconds and the codeless rescan timer exceeds the minimum rescan time. The minimum rescan time is the minimum value of t ₁ and is 5.3704 in the above example. By performing a test of the codeless rescan timer, the PCC 101

It ensures that you have the opportunity to receive one of two possible transmissions. If a cellular rescan occurs, the PCC 101 skips resetting the codeless known rescan timer at 1125 and proceeds to 1127.

If cellular rescan is not needed, a test is performed at 1147 to determine whether a codeless known rescan should occur. Codeless known rescan occurs when the codeless known rescan timer exceeds the CBRT and the cellular rescan timer is greater than the minimum rescan time. The minimum rescan time is 5.3704 seconds. By performing a test of the cellular rescan timer, it ensures the PCC 101 has the opportunity to receive one of two possible transmissions of the same page. The codeless known rescan timer (CBRT) value must be greater than the t ₁ value of 5.370 seconds. For the preferred embodiment a 60 second CBRT is selected. If no codeless known rescan is needed, the process restarts from the beginning of the idle task (1138). This is the test at 1139.

If codeless rescan is needed, the process begins by resetting the cellular scan counter at 1149. This is also the first state of forced cellular rescan determined at 1139. The cellular scan counter is reset at 1149 to ensure that a forced codeless scan is not unnecessarily determined at 1139. After resetting the cellular scan counter, the signal channel of the codeless base station 115 is scanned at 1151 as described by 103. If the test at 1153 determines that the codeless base is found, it enters the codeless mode and the user knows at 1107. If the codeless base is not found, the PCCPCC 101 must return to the previous control channel at 1155. PCC 101 then delays obtaining word synchronization at 1107. The codeless based rescan timer is reset at 1159 to indicate the time at which the last codeless known casscan occurred. Finally, the process begins with the first part of the idle task 1138 in the test 1139.

Claims (5)

A radiotelephone apparatus having a first mode of operation for generating and receiving telephone calls in a first high power wireless telephone system and a second mode of operation for generating and receiving telephone calls in a second low power wireless telephone system, comprising: A selector automatically between a second mode of operation, a receiver for receiving a telephone call over the first high power wireless telephone system channel during operation in the first mode of operation and the second mode of operation; A transmitter for transmitting telephone calls on one channel of a first high power wireless telephone system, said transmitter operating within said first mode of operation within a range of power levels associated with said first high power wireless telephone system. A power level associated with the second low power wireless telephone system when generating a signal and operating in the second mode of operation; Generating a low signal, wherein the power level associated with the second low power radiotelephone system is within a range of the power levels associated with the first high power radiotelephone system such that the radiotelephone device is configured to provide the first high power. A wireless telephone apparatus that facilitates switching between a wireless telephone system and the first low power wireless telephone system. A method of operating a telephone apparatus having a first mode of operation for generating and receiving telephone calls in a first high power wireless telephone system and a second mode of operation for generating and receiving telephone calls in a second low power wireless telephone system. Automatically selecting between a first mode of operation and a second mode of operation, receiving a telephone call while operating in the first mode of operation and the second mode of operation, and when operating in the first mode of operation Transmitting a telephone call on one channel of the first high power wireless telephone system by generating a signal within a range of power levels related to the first high power wireless telephone system, and when operating in the second mode of operation Generating a signal at a power level associated with the second low power cordless telephone system, thereby generating a signal on a channel of the first high power cordless telephone system. Sending a telephone call, wherein the power level associated with the second low power cordless telephone system is within a range of the power levels associated with the first high power cordless telephone system; A method of operating a radiotelephone device that facilitates switching between a first high power radiotelephone system and the second low power radiotelephone system. The wireless telephone apparatus according to claim 1, wherein said power level associated with a second low power cordless telephone system is a lowest power level of said power level ranges associated with said first high power cordless telephone system. 2. A wireless telephone apparatus according to claim 1, wherein said first high power cordless telephone system is a cellular radiotelephone system and said second low power cordless telephone system is a cordage telephone system. 3. The method of claim 2, wherein transmitting a telephone call in the second mode of operation further comprises generating a signal at a lowest power level of the power level range associated with the first high power wireless telephone system. Wireless telephone apparatus operation method.