HK1048220B

HK1048220B - System and method for identifying user zone using broadcast addressed notification messages

Info

Publication number: HK1048220B
Application number: HK03100355.6A
Authority: HK
Inventors: J‧C‧奥尔特; J‧C‧奧爾特; S‧K‧克哈扎卡
Original assignee: 高通股份有限公司
Priority date: 1999-08-17
Filing date: 2000-08-16
Publication date: 2005-04-01
Also published as: HK1048220A1; AU6647300A; JP2003507947A; KR20020027553A; CN1157093C; CN1379965A; WO2001013670A1

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. In particular, the present invention relates to an improved system and method for using broadcast address feature notification messages to alert wireless device users of the area in which they are currently located.

Background

In wireless communication systems, such as cellular or personal communication devices (PCS) telephone systems, the system is physically divided into a number of coverage areas. Coverage may be defined by both physical and non-physical constraints. The coverage defined by the service provider identity is an example of a non-physical constraint, while the coverage (e.g., cell) defined by a single base transceiver station is a physical constraint on geography, transmitter power, and receiver sensitivity. Service providers divide their 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 region is defined by the service provider at system design time.

Coverage defined by the service provider identity is important for billing purposes. The service provider that assigns the telephone 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 its service provider coverage, it is called roaming. The cost of roaming calls is typically higher than the cost of telephone calls in the home service provider system. Because of the cost difference between the 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 condition. The wireless device typically provides an indicator on the phone display to inform the user of the roaming condition.

The same home/roaming concept can also be used in service provider coverage. The division of the service provider coverage into different zones provides the service provider with offering zones according to a progressive pricing scheme. In this scenario, the radiotelephone user will progressively pay higher call prices as the distance (as measured by the number of zones) from the predetermined local zone increases. Such areas based on progressive pricing schemes are similar to billing practices used by Public Switched Telephone Network (PSTN) service providers. However, unlike the PSTN which formulates call prices based on the area of the dialed number, call prices from wireless telephone based areas are formulated depending on in which area the wireless telephone originated the call.

The problem that wireless telephone users are faced with, but not experienced by, Public Switched Telephone Network (PSTN) telephone users, arises from the mobility of wireless telephones. The mobility of wireless telephones makes it critical to determine the location of wireless telephone areas in real time. When a call is initiated by a wireless telephone, and when the call is placed on hold, the area in which the wireless telephone is located must be determined. During the single call process, the radiotelephone can move from one area to another.

One possible solution requires that the radiotelephone register with the system each time it crosses a zone boundary. In response to the call registration message, the base station tells it what area it is in by responding to the registration call with a message. Each wireless telephone system (regardless of modulation type) has some provisions for mobile phone registration. Code Division Multiple Access (CDMA) cellular SYSTEM interfaces are described in the Mobile STATION-BASE STATION COMPATIBILITY STATION oriented for Mobile-MODE SPREAD Spectrum System, of the Telecommunication Industry Association (TIA) and the Electronics Industry Association (EIA) provisional STANDARDs TIA/EIA/IS-95.

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

In a CDMA system, each base station periodically transmits an additional message on a paging channel to any phone in its coverage area. The additional message is sent to the phone as a system parameters message and includes a System Identification (SID) number and a Network Identification (NID) number. From these two numbers, the phone can determine whether it is in the coverage of its local system. A phone that is not in the local coverage area is considered roaming. Because the charges incurred by a roaming phone are typically higher than the same phone call placed from the home system, the phone will display a roaming status.

In addition, the system parameter message includes a data field of the registration area. The registration zone associated with the SID and NID numbers may initiate the mobile telephone zone upon registration. The phone stores the ZONE in which it is registered as a ZONE LIST, ZONE _ LIST. The number of ZONEs stored in ZONE _ LIST is a variable that can be set by a data field in the system parameter message. The phone compares the SID, NID and registration area information in the received system parameter message with the record 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.

The most recent ZONE _ LIST is maintained by starting the ZONE LIST timer for each record in the ZONE _ LIST. When the timer for any particular record in the ZONE _ LIST expires, that record is cleared from the LIST. Likewise, if the information received in the system parameters message indicates a new ZONE and the maximum number of ZONEs already exist in the ZONE _ LIST, the phone will use the ZONE LIST timer to determine the oldest record and remove it from the LIST.

The registration-based region is particularly useful in maximizing paging channel capacity. The paging message may be directed to those phones that only use the most recently registered base stations. System resources are maximized by eliminating the need to broadcast paging messages to all base stations only to ensure that a single user receives the paging message.

The general area based registration may be modified to allow transmission of area information to the phone whenever the phone enters the area. To achieve this goal, the system needs to be configured such that the number of records maintained in ZONE _ LIST is limited to 1. This ensures that the phone will issue a registration message whenever the phone crosses an area boundary. In response to the phone registration, the base station sends a direction message to the registered phone informing the user of the zone status. The instructional message may be a text message that is displayed to the user. The user will then always know the current zone status and will presumably know the corresponding billing price in that zone.

However, there are a number of drawbacks in a system configured in this manner. Since the number of records in the telephone ZONE _ LIST is reduced to 1, the number of times the telephone must 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 region between two regions. When the phone is operating in a border area, it is likely to make multiple spans between the coverage areas in both areas. Since the number of records in ZONE _ LIST is limited to 1, the phone must send a registration message each time a system parameter message indicating a different ZONE is received. The result is a significant increase in the number of times the phone must send a registration message. The increased number of times the registration message is sent results in a drain of power in the phone, thereby reducing the phone active standby and talk time. Many phones continually send registration messages that can overburden the access channel. As long as there is a zone boundary on the main channel, there is a problem of overloading the access channel with a large number of simultaneous active registration messages.

In addition, each registration message triggers a supplementary tutorial message that informs the area to register the phone. The tutorial messages are sent to the individual phones according to their definitions. The amount of the guide message is greatly increased by the current design method of informing the phone user of the relevant area information. This results in a loss of capacity of the paging channel.

The loss of access channel and paging channel capacity is not balanced against the benefit of users knowing their current location. Moreover, if the progressive-price-scheme-based region is used by only a few of the users supported by the service provider, it is very disadvantageous for the system and for most users, in case a small number of users are favored. Each telephone user has less talk time and standby time due to the increased number of registration messages required for the telephone, and supplementing the received zone information is helpful only to a few of the users of the progressive pricing scheme.

What is needed is a system and method for prompting subscriber zone information in a progressive price calling plan without degrading wireless system performance or compromising subscriber interest not on the same calling plan.

Disclosure of Invention

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

The base station periodically sends a broadcast address characteristic prompt or SMS message containing a text message informing the subscriber of the area in which the base station is located. Telephones on areas based on progressive pricing schemes are assigned a specific broadcast address. Other phones using other calling schemes do not assign the same broadcast address. A phone with a broadcast address can determine that the address information is directed to the phone. Phones that do not have a broadcast address simply discard the information. Thus, a phone on a progressive pricing scheme can keep the user updated with regional information. This has no adverse effect on those phones that do not belong to the progressive pricing scheme. System capacity on the access channel is maintained because the telephone is not required to send registration messages in response to zone information messages. The capacity on the paging channel is only reduced by a nominal amount and not to the reduced level when using the tutorial message. The use of broadcast messages is more efficient than tutorial messages because they allow a single transmission directed to many users, while tutorial messages only allow only one recipient at a time to be transmitted.

Drawings

The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein:

FIG. 1 is a diagram depicting a system implementation of the present invention and showing the effect of varying area boundaries and users moving within the boundary range; and

fig. 2 is a flowchart illustrating a region notification method.

Detailed Description

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

A feature notification message is sent from the base station to the phone over the paging channel. A field in the feature notification message allows the message to be addressed using broadcast.

Broadcast addressing allows a base station to simultaneously direct a single message to many phones. Many phones may share the same broadcast address. The phone will process the broadcast address message provided that the phone is configured to receive the message and is configured with a specific broadcast address. This is in contrast to the base station sending a tutorial message to a particular 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 can provide useful information. In the case of progressive price accounting based zones, those phones on the price plan are assigned a particular broadcast address, and any phone not on the price plan does not include that address. Only those phones on the progressive pricing scheme will process the zone identification messages sent using broadcast addressing. This is in contrast to the method of registering every time a phone crosses a zone boundary. The phone registration cannot be configured differently between phones in the same system. If all phone registrations are required whenever a zone boundary is crossed, the wireless phone will have a significant reduction in capacity to benefit users who are a small percentage of the total number of users.

The benefit provided to the user of the progressive pricing scheme is information identifying the area in which the phone is located. In addition to utilizing broadcast addressing control messages, the feature notification messages may be configured to provide a "display" record. The use of the "show" record indicates that the phone and the content of the feature notification message is alphanumeric symbols to be displayed on the phone. The specific alphanumeric message sent by each base station is information for that area (e.g., "You are in zone 3." or "welome to down" or "City Mall", etc.). The user can then decide whether a telephone call from a particular area would cause an increase in cost. By periodically sending feature notification messages, any phone entering the area can be notified of the change in status of the area. Without the phone needing to have transmission activity. Furthermore, because broadcast addressing is used, only those phones to which the message is destined will process and display the message.

Short Message Service (SMS) messages may be used as an alternative to feature notification messages. SMS messages are primarily used to send alphanumeric information to wireless telephones. A generalized description of SMS in CDMA telephone SYSTEMs IS found in the telecommunication industry Association and the electronics industry Association TIA/EIA/IS-637, SHORT MESSAGESTERICES FOR WIDEBAND SPREAD SPECTRUM CELLULAR SYSTEM. The message may be generated at a message center and sent to the telephone through the base station. Messages may also be generated in the phone and sent to the message center via the base station. Only a periodic transmission of area information from the base station to the phone is involved here.

Messages sent from the base station to the telephone may be sent on a paging or traffic channel. The message sent to the phone IS formatted as a data burst message as defined by TIA/EIA/IS-95. In the case of feature notification messages, the messages may be sent as point-to-point directed messages to individual users, or may be sent as broadcast messages simultaneously to many phones.

The operation of the present invention is shown in figure 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 comprising each base station 110 or 120 are not important to the present description and are therefore assumed to be included in the figure representing each base station 110 or 120.

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

When the mobile phone 141 passes through the boundary range between the zones, the coverage will vary between the first base station 110 and the second base station 120. For a given path 142 along the boundary range, the mobile phone will cross the regional 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 in 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, the corresponding forward link 124 and reverse link 122 channels will be supported by the second base station 120.

In existing embodiments, the zone location of mobile phone 141 is updated by requiring the mobile phone to register each time it crosses zone boundary 130. The system parameter message received by mobile phone 141 will be generated by a different base station each time the mobile phone crosses area boundary 130. Using the scenario shown in fig. 1, the mobile station 141 initially operates in the coverage area defined by the first base station 110. The system parameter message broadcast from the first base station 110 identifies the area in which the first base station 110 is located. Upon first entering the area and receiving the system parameters message on the forward link 114 paging channel, mobile phone 141 sends a registration message to first base station 110 on the reverse link 112 access channel. The first base station 110 responds by sending a direction message containing the zone information to the mobile phone 141 on the paging channel. As the mobile phone 141 moves along the path 142 in the interfacing zone, it crosses the zone boundary 130. Once the mobile phone 141 crosses the area boundary 130, coverage is provided by the second base station 120. The second base station 120 sends out a system parameter message indicating the different area. In response to the region indication being different from the region in which mobile phone 141 has registered, the mobile phone sends another registration message to second base station 120 on the reverse link 122 access channel. The second base station 120 then sends a guide message containing the zone information to the mobile phone 141 in response. This system parameter message scenario indicating a change in area after mobile phone 141 registration and base station directed messaging repeats each time mobile phone 141 crosses area boundary 130. When the registration is multiplied by the number of phones crossing the zone boundary at any given time, it can be seen that the load present in the wireless system is considerable.

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

By implementing the invention in a system that re-reviews the situation of fig. 1, it can be seen that the invention does not require the mobile telephone 141 to transmit. But each base station 110 or 120 periodically transmits a broadcast address characteristic notification message or SMS message containing a regional information display record. The period for which the base station 110 or 120 repeats the feature notification message is determined by system design and is typically in the range of 5-15 seconds. When the mobile phone 141 is in a particular area, it receives and processes the feature notification message and displays area information to the user. As the mobile phone 141 proceeds along the path 142 on the inter-area boundary, 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 mobile phone 141 corresponds to the area in which it is currently located. The mobile phone 141 does not need to actively transmit in order to know the current area. This reduces the load on the access channel and conserves power in the phone. In addition, because the base stations 110 and 120 can use the broadcast address message instead of the guide message, the load on the paging channel is reduced. It can be seen that the further mobile phones 150 and 160 operating in the zone border do not increase the load on the system. Each base station 110 or 120 sends zone notification messages regardless of the number of mobile phones 141, 150, and 160 that cross the zone boundary 130. Each mobile phone 141, 150, and 160 displays an area notification message corresponding to the base station 110 and 120 providing area coverage.

The method of zone notification is summarized in fig. 2. After the method is started 200, a zone notification message is sent from the base station 204. The base station does not send the zone notification message in response to an event, but rather the sending of the message is the only zone 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 simultaneously. At decision step 208, the limitation of the coverage of the base station only allows the programming process to be performed substantially when the phone is in its coverage area. No device actually performs the determination, but rather makes the determination through physical coverage limitations. If the phone is not in the coverage area of the transmitting base station, the transmitted signal is too weak for reception by the phone. The process ends at 240. If there is a phone in the coverage area, the phone receives an area notification message 210. At decision step 220, the phone checks whether the message is directed to the phone. This check is accomplished by comparing the broadcast address of the zone notification message with a predetermined address 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 process ends at 240. If the broadcast address matches an address stored in the phone, the phone processes the message 224 and displays the content of the message to the user 228. If the method of fig. 2 is repeated on a periodic basis, each phone in the coverage area of the base station will be continuously updated with the correct area information.

The previous description of the preferred embodiments is provided to enable any person skilled in the art to make or use the present 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 the use of the inventive faculty. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wireless communication system for informing users of a predetermined area in which they are located, the system comprising:

a plurality of base stations defining a plurality of predetermined areas, each area consisting of one or more base stations; and

a plurality of mobile units having a specific broadcast address and capable of moving within said predetermined area and receiving messages using broadcast addressing;

wherein each base station transmits area information corresponding to a predetermined area in which the base station is located, and wherein each mobile unit provides an indication to a user that an area exists by receiving and processing the area information message from the base station with which the mobile unit is currently communicating in accordance with the broadcast address.

2. The wireless communication system of claim 1, wherein each base station periodically transmits a zone information message.

3. The wireless communication system of claim 1, wherein the zone information message is a feature notification message.

4. The wireless communication system of claim 3, wherein the feature notification message indicates a record type.

5. The wireless communication system of claim 4, wherein the indication of the presence of the user area is the content of a feature notification message display record.

6. The wireless communication system of claim 1,

the zone information message is a short message service, SMS, message.

7. A method for informing a plurality of radiotelephone users of a predetermined area in which they are located, the method comprising the steps of:

transmitting an area information message from a base station using broadcast addressing;

receiving the zone information message by a wireless telephone having a particular broadcast address;

processing the zone information message in the radiotelephone if the radiotelephone is configured to receive the zone information message address; and is

Indicating to the wireless telephone user that a zone corresponding to the zone information message content exists.

8. The method of claim 7, wherein the steps are repeated periodically.

9. The method of claim 7, wherein the zone information message is a feature notification message.

10. The method of claim 9, wherein the feature notification message is broadcast addressed.

11. The method of claim 10, wherein the feature notification message defines a display record type.

12. The method of claim 11 wherein the indicating step is performed only if the wireless telephone has the same broadcast address as used in the feature notification message.

13. The method of claim 7, wherein the zone information message is a Short Message Service (SMS) message.