CN1157093C - System and method for identifying user zone using broadcast addressed notification messages - Google Patents

Abstract

A system and method for providing zone specific information to the user of a wireless terminal, e.g. a phone. Zone specific information is periodically transmitted (204) to users over a common overhead link using an available messaging format. If the phone is located within the zone, it will receive the information (208, 210). If the information is directed to that phone (220), the phone will process the information (224) and display information to the user (228). If the information is not directed to that phone (220), the information is discarded (230). An example of an implementation in a CDMA wireless phone system is to provide zone specific information using the Feature Notification Message broadcast over the Paging Channel of a particular zone. The information is provided using broadcast addressing. Broadcast of the zone specific information over the Paging Channel using the Feature Notification Message results in a reduction in the number of Access Channel registration messages required of mobile phones. A second embodiment uses broadcast addressing in conjunction with Short Message Services (SMS) to provide zone specific information. Broadcast addressing is advantageous in that zone specific information can be sent to subsets of wireless terminals. This allows broadcast in the same zone of a variety of zone specific information that targets different wireless terminals.

Description

System and method for identifying user area using notification message of broadcast address

technical field

The present invention relates to wireless communications. More particularly, the present invention relates to an improved system and method for alerting wireless device users of their current area using broadcast address feature notification messages.

Background technique

In a wireless communication system, such as a cellular or personal communication set (PCS) telephone system, the system is physically divided into a number of coverage areas. Coverage can be defined by a combination of physical and non-physical constraints. Coverage defined by service provider identity is an example of a non-physical constraint, whereas coverage defined by a single base transceiver station (eg cell) is physically constrained by geography, transmitter power, and receiver sensitivity. A service provider divides its service area into many smaller areas. Each area contains at least a cell defined by a single base transceiver station, and may contain many cells. The size of each zone is defined by the service provider during system design.

Coverage defined as a service provider is important for billing purposes. The service provider that assigns the phone number and provides billing for a particular wireless device is also designated as the local service provider for that device. When a wireless device is used outside of its service provider's coverage area, it is called roaming. Roaming calls are usually more expensive than calls made in the local service provider's system. Because of the difference in charges between local and roaming calls, the wireless device uses additional information sent from the base station to the wireless device to inform the user when the phone is in a roaming situation. Wireless devices typically provide an indicator on the phone display to inform the user of roaming conditions.

The same home/roaming concept can also be used in service provider coverage. The division of service provider coverage into different regions provides service providers with the ability to offer regions based on progressive pricing schemes. In such an arrangement, radiotelephone users would pay progressively higher call prices as the distance from the predetermined local area (measured by the number of areas) increases. Such areas based on a progressive pricing scheme are similar to billing practices used by public switched telephone network (PSTN) service providers. Unlike the PSTN, however, where calls are priced based on the region of the dialed number, region-based calls from a wireless phone are priced based on the region in which the wireless phone originated the call.

A problem faced by wireless telephone users that users of public switched telephone network (PSTN) telephones do not experience is caused by the mobility of the wireless telephone. The mobility of radiotelephones makes it critical to determine the location of a radiotelephone area in real time. When a radiotelephone originates a call, and when the call is placed on hold, the zone in which the radiotelephone is located must be determined. During the course of a single call, a wireless telephone may move from one area to another.

One possible solution would require the wireless phone to register with the system each time it crosses a zone boundary. In response to the phone registration message, the base station responds to the registration phone with a message telling it what zone it is in. Every wireless telephone system (regardless of modulation type) has some provisions for mobile phone registration. The code division multiple access (CDMA) cellular system interface is contained in the MOBILE STATION-BASE STATION COMPATIBILITY STANDARD FORDUAL-MODE SPREAD SPECTRUM SYSTEM of the interim standard TIA/EIA/IS-95 of the Telecommunications Industry Association (TIA) and the Electronic Industries Association (EIA) illustrate.

CDMA cellular phones have multiple registration modes as defined in TIA/EIA/IS-95. The standard defines 9 different registration methods supported in CDMA systems. The different forms of registration are power up, power down, timer based, distance based, zone based, ordered, communication channel, parameter change and implicit.

In a CDMA system, each base station periodically sends additional messages on a paging channel to any telephone in its coverage area. Additional messages are sent to the phone as system parameter messages and include the system identification (SID) number and network identification (NID) number. From these two numbers, the phone can determine whether it is within the coverage of its home system. A phone that is not in the home coverage area is considered to be roaming. Because the charges incurred by a roaming call are usually higher than the same phone call placed from the home system, the phone displays a roaming status.

In addition, the system parameter message includes a data field of the registered area. A registration zone associated with a SID and NID number can activate a mobile phone zone upon registration. The phone stores the zones it is registered in as a list of zones, ZONE_LIST. The number of zones stored in ZONE_LIST is a variable that can be set by the data field in the system parameter message. The phone compares the SID, NID, and registration zone information in the received System Parameters message with the records in ZONE_LIST. If the SID, NID and registration zone information are not already stored in the ZONE_LIST, the phone starts registration on the access channel.

Keep a recent ZONE_LIST by starting a zone list timer for each record in the ZONE_LIST. When the timer for any particular record in ZONE_LIST expires, that record is removed from the list. Likewise, if the information received in the System Parameters message indicates a new zone, and the maximum number of zones already exists in the ZONE_LIST, the phone will use the zone list timer to determine the oldest record and remove it from the list.

Registration based areas are particularly useful in maximizing paging channel capacity. Paging messages can be directed to phones using only the most recently registered base stations. System resources are maximized by eliminating the need to broadcast paging messages to all base stations just to ensure that a single user receives the paging message.

Registration-based universal zones can be modified to allow zone information to be sent to phones whenever the phone enters the zone. To achieve this goal, the system needs to be configured so that the number of records maintained in ZONE_LIST is limited to 1. This ensures that the phone sends out registration messages whenever the phone crosses a zone boundary. In response to phone registration, the base station sends a guidance message to the registered phone informing the user of the status of the area. The guidance message may be a text message displayed to the user. The user will then always know the current zone status and will roughly know the corresponding billing price in that zone.

However, there are a number of drawbacks in systems configured in this way. Since the number of records in the phone's ZONE_LIST is reduced to 1, the number of times the phone has to be registered in the system will increase. The increase in the number of registration messages sent by the phone is most pronounced when the phone is operating in the boundary range between two regions. When a phone is operating in a border area, it is likely to make multiple crossovers between coverage areas in the two areas. Since the number of records in the ZONE_LIST is limited to 1, the phone must send a Registration message every time it receives a System Parameters message indicating a different zone. The result is a dramatic increase in the number of times the phone must send registration messages. The increased number of times registration messages are sent results in draining the battery in the phone, thereby reducing the effective standby and talk time of the phone. The constant sending of registration messages by many phones can overburden the access channel. As long as there are zone boundaries on the main channel, there is the problem of overloading the access channel due to the simultaneous active registration of messages by a large number of phones.

In addition, each registration message triggers a supplemental guidance message informing the area registration phone. Guidance messages are sent to individual phones according to their definition. With the current design approach of informing the phone user of information about the area, the volume of instructional messages would be greatly increased. This results in a loss of capacity for the paging channel.

The loss of access channel and paging channel capacity is not balanced by the benefit of users knowing the area they are currently in. Furthermore, if a region based on a progressive pricing scheme is only used by a minority of the users supported by the service provider, it is very detrimental to the system and to the majority of users, while benefiting a small number of users. Each phone user has less talk time and standby time due to the increased number of registration messages required for the phone, and additionally received regional information is only helpful to a minority of progressive price plan users.

What is needed is a system and method for prompting users in progressive price calling plans for zone information without degrading wireless system performance or harming users who are not on the same calling plan.

Contents of the invention

The present invention is an improved system and method for prompting users with relevant area information by using a broadcast address characteristic notification message. Alternatively, the user may be informed of the region information using a Short Message Service (SMS) message.

The base station periodically sends a broadcast address characteristic reminder or an SMS message containing a text message, which informs the user of the area where the base station is located. Assign specific broadcast addresses to phones on regions based on progressive pricing plans. Other phones using other calling plans are not assigned the same broadcast address. A phone with a broadcast address can determine that the address information is directed to that phone. Phones that do not have a broadcast address simply discard this information. Thus, a phone on a progressive price plan can continuously update the user with zone information. This has no adverse effect on those phones that are not part of the progressive price plan. System capacity on the access channel is preserved because the phone is not required to send registration messages in response to area information messages. The capacity on the paging channel is only reduced by a nominal amount and will not be reduced to the reduced level when using the guidance message. The use of broadcast messages is more efficient than directed messages because broadcast messages allow a single transmission directed to many users, whereas directed messages only allow one recipient per transmission.

Description of drawings

The features and advantages of the present invention will become more apparent from the detailed description given below when taken in conjunction with the accompanying drawings in which like reference characters correspond consistently throughout the description:

Figure 1 is a diagram describing a system implementation of the present invention and showing changing area boundaries and the effect on users moving within the boundaries; and

FIG. 2 is a flowchart illustrating an area notification method.

Detailed ways

In a CDMA wireless telephone system operating according to TIA/EIA/IS-95, there are several message formats that can be used to send information from the base station to the telephone. Two such available message formats are feature notification messages and Short Message Service (SMS).

Feature notification messages are sent from the base station to the phone on the paging channel. A field in the Feature Notification message allows the message to utilize broadcast addressing.

Broadcast addressing allows a base station to direct a single message to many phones simultaneously. Many phones can share the same broadcast address. Provided the phone is configured to receive broadcast address messages, and is configured with a specific broadcast address, the phone will process the message. This is quite different from the direction message that the base station sends to a specific phone using the phone's mobile station identification number.

The use of broadcast addressing is advantageous because a message can be directed to many recipients, and also because a message can be provided only to those individuals for whom the message provides useful information. In the case of zones based on progressive price billing, those phones on the price plan are assigned a specific broadcast address, any phone not on that price plan does not include this address. Only those phones on the progressive price plan will process zone identification messages sent using broadcast addressing. This is very different from the method when a phone has to register every time it crosses a zone boundary. Phones registered in the same system cannot be configured differently between phones. If all phone registrations were required as long as they crossed area boundaries, there would be a significant reduction in radiotelephone capacity to benefit a small percentage of the total number of users.

A benefit provided to users of progressive pricing plans is information identifying the region in which the phone is located. In addition to utilizing broadcast addressed control messages, Feature Notification messages can be configured to provide "display" records. The use of the "Display" record indicates to the phone that the content of the feature notification message is an alphanumeric symbol to be displayed on the phone. The specific alphanumeric message sent by each base station is information about the zone (eg "You are inzone 3." or "Welcome to downtown" or "City Mall", etc.). The user can then determine whether a phone call from a particular area would incur an increase in charges. By periodically sending feature notification messages, any phone that enters the zone can be notified of changes in zone status. The phone does not need to have send activity. Also, because broadcast addressing is used, only those phones to which the message is intended will process and display the message.

Short Message Service (SMS) messages can be used as an alternative to feature notification messages. SMS messages are primarily used to send alphanumeric information to wireless phones. A general description of SMS in CDMA telephone systems can be found in the Telecommunications Industry Association and the Electronic Industries Association TIA/EIA/IS-637, SHORT MESSAGES SERVICES FOR WIDEBAND SPREAD SPECTRUM CELLULAR SYSTEM. Messages can be generated at the message center and sent to the phone via the base station. Messages can also be generated in the phone and sent to a message center via the base station. This is only concerned with the periodic transmission of area information from the base station to the telephone.

Messages sent from the base station to the phone can be sent on paging or traffic channels. Messages sent to the phone are formatted as data burst messages as defined by TIA/EIA/IS-95. As in the case of feature notification messages, messages can be sent as point-to-point directed messages to individual users, or as broadcast messages to many phones simultaneously.

The operation of the present invention is shown in FIG. 1 . Referring to FIG. 1, a portion of a wireless system 100 is shown. The first base station 110 provides coverage on one side of the area boundary 130 . The second base station 120 provides coverage on the opposite side of the area boundary 130 . Many of the elements that comprise each base station 110 or 120 are not critical to this description and are thus assumed to be included in the diagram representing each base station 110 or 120 .

Region boundaries 130 are depicted as randomly varying curves to emphasize that non-contiguous region boundaries cannot be defined. Although, the zone boundaries 130 can be clearly defined in the system design, the actual zone boundaries 130 will vary due to many factors including terrain, RF obstructions, and antenna pattern. A user 140 operating a mobile telephone 141 within the service area of the wireless system 100 communicates with at least one base station (110 or 120) at any given time.

The coverage will vary between the first base station 110 and the second base station 120 as the mobile phone 141 passes the boundary between areas. For a given path 142 along the boundary range, the mobile phone will cross the area boundary 130 multiple times. Both the forward link 114 information and the reverse link 112 information will be supported by the first base station 110 when the mobile phone 141 is within the coverage area defined by the first base station 110 . Likewise, when the mobile phone 141 is within the coverage area defined by the second base station 120 , both corresponding forward link 124 and reverse link 122 channels will be supported by the second base station 120 .

In the present embodiment, the zone location of the mobile phone 141 is updated by requiring the mobile phone to register each time the zone boundary 130 is crossed. Each time the mobile phone crosses the zone boundary 130, the system parameter message received by the mobile phone 141 will be generated by a different base station. Taking the situation shown in FIG. 1 , the mobile station 141 is initially operating in the coverage area defined by the first base station 110 . The area where the first base station 110 is located is identified from the system parameter message broadcast by the first base station 110 . Upon first entering the area and receiving a system parameter message on the forward link 114 paging channel, the mobile phone 141 sends a registration message to the first base station 110 on the reverse link 112 access channel. The first base station 110 responds by sending a direction message containing area information to the mobile phone 141 on the paging channel. When mobile phone 141 moves along path 142 in the demarcated area, it crosses area boundary 130 . Coverage is provided by the second base station 120 once the mobile phone 141 has crossed the area boundary 130 . The second base station 120 sends a system parameter message indicating different areas. In response to an indication of an area different from the area in which the mobile phone 141 is already registered, the mobile phone sends another registration message to the second base station 120 on the reverse link 122 access channel. Then the second base station 120 sends a guidance message including area information to the mobile phone 141 as a response. This situation of the system parameter message indicating the change of zone after the registration of the mobile phone 141 and the guidance message transmission of the base station will be repeated each time the mobile phone 141 crosses the zone boundary 130 . When the registrations are multiplied by the number of phones crossing zone boundaries at any given time, it can be seen that the load present on the wireless system is considerable.

Additional mobile phones 150 and 160 operating along the zone boundary 130 will traverse along separate paths 152 and 162, respectively. When the mobile phone 150 traverses the path 152, it will cross the area boundary 130 twice and will be required to register each time it crosses the boundary 130. Mobile phone 150 will receive zone information in response to each registration. Likewise, a third mobile phone traversing along the independent path 162 will be required to send a registration message and receive a zone information response each time it crosses the zone boundary 130 . The constant registration messages from the mobile phone 141 reduce the capacity of the access channel, while the numerous guidance messages from the base station 110 or 120 also reduce the capacity of the paging channel.

With the present invention implemented in the system, reviewing the situation of FIG. 1, it can be found that the present invention does not require the mobile phone 141 to transmit. Instead, each base station 110 or 120 periodically sends a broadcast address feature notification message or SMS message containing the area information display record. The period at which the base station 110 or 120 repeats the feature notification message is determined by system design, and is usually in the range of 5-15 seconds. When the mobile phone 141 is in a specific area, it receives and processes the feature notification message and displays the area information to the user. When the mobile phone 141 moves along the path 142 on the boundary between regions, the mobile phone 141 alternately receives feature notification messages from the first base station 110 or the second base station 120 . The feature notification message received and processed by the mobile phone 141 corresponds to its current area. The mobile phone 141 does not need to actively send in order to know the current area. This reduces the load on the access channel and conserves power in the phone. Additionally, since base stations 110 and 120 can use broadcast address messages instead of direction messages, the load on the paging channel is reduced. It can be found that the additional mobile phones 150 and 160 operating in the zone borders do not increase the load on the system. Each base station 110 or 120 sends an area notification message regardless of the number of mobile phones 141 , 150 and 160 crossing the area boundary 130 . Each mobile phone 141, 150 and 160 displays an area notification message corresponding to the base stations 110 and 120 providing area coverage.

The method of zone notification is summarized in FIG. 2 . After starting 200 the method, the secondary base station 204 sends an area notification message. The base station does not send an area notification message in response to an event, but the sending of the message is the only area notification activity required by the base station. The base station configures the message as a broadcast address message so that the message can be directed to multiple phones at the same time. In decision step 208, the limitations of the base station's coverage area effectively only allow processing to proceed while the phone is within its coverage area. No device actually performs the decision, but rather the decision is made through physical coverage limitations. If the phone is not in the coverage area of the transmitting base station, the transmitted signal will be too weak for the phone to pick up. The routine thus ends at 240 . If there is a phone in the coverage area, the phone receives the area notification message 210 . In decision step 220, the phone checks to see if the message is directed to the phone. This check is performed by comparing the broadcast address of the zone announcement message with predetermined addresses stored in the phone. If the broadcast address is not an address stored in the phone, the phone determines that the message is not directed to it. Thus, the phone discards the message 230 and the procedure ends at 240. If the broadcast address matches the address stored in the phone, the phone processes the message 224 and displays the contents of the message to the user 228 . If the method of FIG. 2 is repeated on a periodic basis, each phone within the coverage of the base station will continue to be updated with correct zone information.

The foregoing description of the preferred embodiment is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without resort to inventive step. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope associated with the principles and novel features disclosed herein.

Claims (13)

1, a kind of wireless communication system that is used to inform their presumptive area that is positioned of user is characterized in that described system comprises:

Defined a plurality of base stations of a plurality of presumptive areas, each zone is made up of one or more base stations; And

Have specific broadcast address and can in described presumptive area, move and utilize broadcast addressing to receive a plurality of mobile units of message;

Wherein, each base station sends the area information corresponding to place, base station presumptive area, and wherein each mobile unit comes the indication that provides the zone to exist for the user by receive and handle described area information message from the base station of the present ongoing communication of described mobile unit according to described broadcast address.

2, wireless communication system as claimed in claim 1 is characterized in that, described each base station is the sending zone informational message periodically.

3, wireless communication system as claimed in claim 1 is characterized in that, described area information message is feature notice message.

4, wireless communication system as claimed in claim 3 is characterized in that, described feature notice message displayed record type.

5, wireless communication system as claimed in claim 4 is characterized in that, the indication that described user area exists is the content of feature notice message displayed record.

6, wireless communication system as claimed in claim 1 is characterized in that,

Described area information message is Short Message Service SMS message.

7, a kind of method that is used to inform their presumptive area that is positioned of a plurality of wireless telephone users is characterized in that described method comprises the steps:

Utilize broadcast addressing from sending zone, base station informational message;

Receive described area information message by radio telephone with specific broadcast address;

If described radio telephone is configured to receive described area information message addresses, just in this radio telephone, handle described area information message; And

The zone of described wireless telephone user indication corresponding to described area information message content existed.

8, method as claimed in claim 7 is characterized in that, periodically repeats described step.

9, method as claimed in claim 7 is characterized in that, described area information message is feature notice message.

10, method as claimed in claim 9 is characterized in that, described feature notice message is to broadcast addressing.

11, method as claimed in claim 10 is characterized in that, described feature notice message has defined the displayed record type.

12, method as claimed in claim 11 is characterized in that, only when radio telephone has the broadcast address identical with employed address in the feature notice message, just carries out described indication step.

13, method as claimed in claim 7 is characterized in that, described area information message is Short Message Service SMS message.

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