KR20020027553A - System and method for identifying user zone using broadcast addressed notification messages - Google Patents

Abstract

The present invention relates to a system and method for providing zone specific information to a user of a wireless terminal such as, for example, a telephone. Zone specific information is periodically sent 204 to the user over a common overhead link using a periodically available message format. If the phone is located in the area, the phone receives the information (208, 210). If the information is passed to the telephone (220), the telephone processes the information (224) and displays the information to the user (228). If the information is not passed to the telephone (220), the information is discarded (230). An embodiment of a CDMA wireless telephone system is to provide zone specific information using feature notification message broadcast over a paging channel of a specific zone. This information is provided using broadcast addressing. The release of zone specific information over the paging channel using the feature notification message reduces the number of access channel registration messages required for the mobile phone. The second embodiment uses broadcast addressing in connection with short message service (SMS) to provide zone specific information. Broadcast addressing is useful in that zone specific information can be sent to a subset of wireless terminals. This allows broadcasting of various zone specific information targeting different wireless terminals in the same zone.

Description

SYSTEM AND METHOD FOR IDENTIFICATION OF USER ZONE USING BROAD ADDRESS NOTIFICATION MESSAGE

In wireless communication systems, such as cellular or personal cell phone (PCS) telephone systems, the system is physically divided into several service areas. Service areas may be defined by physical and nonphysical constraints. Service areas defined by the service provider's identity are examples of non-physical constraints, while service areas defined by a single base station transceiver (ie, cell) are physically constrained by geography, transmitter power, and receiver sensitivity. The service provider divides its service area into several smaller areas. Each zone encloses a number of cells with a minimum surrounding of a cell defined by a single base station transceiver. The size of each zone is defined by the service provider when designing the system.

Service areas defined by the service provider's identity are important when charging. A service provider that assigns a phone number and charges a particular wireless device is referred to as a home service provider for that device. If the wireless device is used outside the service area of the service provider, the wireless device is considered roaming. Phone call roaming costs are generally higher than phone call costs in home service provider systems. Because of the cost difference between home and roaming calls, the wireless device uses the overhead information sent from the base station to the wireless device to inform the user when the phone is in a roaming condition. Wireless devices typically provide an indicator on the phone display to alert the user of roaming conditions.

The same home / roaming concept may be used within the service provider service area. The division of service provider service areas into separate zones provides an opportunity for service providers to supply zones based on progressive pricing schemes. In this manner, the wireless telephone user will progressively pay more call charges as the distance from the predetermined home zone (measured in the number of zones) increases. This zone, based on the progressive billing scheme, is similar to the billing scheme used by public switched telephone network (PSTN) service providers. However, unlike in the case of the PSTN, where the call charge is based on the zone of the called number, the call charge from the zone based on the wireless telephone is based on the zone where the wireless telephone originates the call.

One problem that PSTN telephone users do not experience but wireless telephone users experience arises from the mobility of wireless telephones. The mobility of a wireless telephone has a significant impact on the real time determination of the zone area of the wireless telephone. If the wireless telephone initiates the call and the call continues, the zone in which the wireless telephone resides must be determined. Wireless telephones can move between zones during a single call.

A possible solution is to require the wireless telephone to register with the system every time the telephone crosses a zone boundary. In response to the telephone registration message, the base station responds with a message indicating the area in which the telephone is currently registered. Regardless of the type of modulation, all wireless telephone systems have certain provisions for mobile phone registration. Code Division Multiple Access (CDMA) cellular system interfaces are disclosed in the TIA / EIA / IS-95 Mobile Station-Base Station Compatibility Standard for Dual Mode Spread Spectrum Systems, an interim standard for the Telecommunications Industry Association (TIA) and the Electronics Industry Association (EIA).

As defined in TIA / EIA / IS-95, CDMA cellular telephones have multiple registration modes. The standard defines nine different registration methods supported for CDMA systems. Various forms of registration are power up, power down, timer based, distance based, zone based, sort order, traffic channel, parameter change and immanence.

In a CDMA system, each base station periodically sends an overhead message on the paging channel to a telephone in the service area. The overhead information is sent to the phone as a system parameter message and includes a system identification (SID) number and a network identification (NID) number. From these two numbers the phone can determine if it is within its home system coverage. Phones not in the home service area are considered roaming. The phone displays the roaming status to the user because the charges incurred in roaming phone calls are generally more expensive than the charges for the same phone call formed from the home system.

In addition, the system parameter message includes a data field for the registration area. Registration zones associated with SID and NID numbers may trigger mobile phone zones based on registration. The phone stores ZONE_LIST, which is a list of registered zones. The number of zones stored in ZONE_LIST is a variable that can be set by the data field of the system parameter message. The phone compares the list of ZONE_LIST with the SID, NID and registration zone information received in the system parameter message. If the SID, NID and registration zone information have not yet been stored in ZONE_LIST, the phone initiates registration on the access channel.

ZONE_LIST maintains its current state by starting a zone list timer on every entry of ZONE_LIST. If the timer expires during a particular input of ZONE_LIST, the input is removed from the list. Similarly, if the information received in the system parameter 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 input and delete it from the list.

Registration based zones are particularly useful for maximizing paging channel capacity. The paging message may be delivered to the phone using only the base stations for which the phone was recently registered. This maximizes system resources by eliminating the need to broadcast a paging message to all base stations just to allow a single user to receive a paging message.

The general zone based on registration may be modulated such that zone information is transmitted to the telephone whenever the telephone enters the zone. To accomplish this, the system needs to be configured so that the number of inputs kept in ZONE_LIST is limited to one. This causes the phone to initiate a registration message each time it crosses a zone boundary. In response to the telephone registration, the base station sends a directional message to the registered telephone to inform the user of the zone status. This directional message will be a text message displayed to the user. The user will then always know the current zone status and how much the charges are for that zone.

However, there are several disadvantages to configuring the system in this way. Since the number of entries in the phone ZONE_LIST is reduced to 1, the number of times the phone must register with the system will be multiplied many times. The increase in the number of registration messages sent by the phone is most pronounced when the phone operates in the boundary area between the two zones. If the phone operates in the border zone, the phone will alternate between service areas in the two zones multiple times. The number of entries in ZONE_LIST is limited to 1 and the phone is asked to send a registration message whenever it receives a system parameter message indicating another zone. As a result, the number of times a telephone is requested to send a registration message increases significantly. Increasing the number of registration messages sent depletes the battery's battery energy, thereby reducing the standby and talk time of the available telephones. Access channels are overloaded as several phones continue to send registration messages. If a zone boundary occurs on the main passage, a problem arises in which a large number of telephones simultaneously overload the access channel with a registration message.

In addition, each registration message triggers a secondary directing message indicating the zone to the registering phone. The directional message is sent to the individual phone by each definition. The number of directional messages increases significantly in the current planned way of informing the zone user of the zone information. This causes capacity loss on the paging channel.

The loss of access channel and paging channel capacity is not balanced with the user's advantage of knowing in which zone they are present. In addition, if the area based on the progressive fee scheme is used only by a small number of subscribers supported by the service provider, the system and the large number of subscribers are greatly disadvantaged to provide a benefit to a small number of users. Each telephone user has less telephone call time and waiting time because of the increased number of requested registration messages of the telephone, and the coverage area information is only available to a small number of progressive toll subscribers.

Accordingly, what is needed is a system and method for informing zone information to users with progressive toll calling methods without penalizing wireless systems or users that do not have the same calling method.

The present invention relates to the field of wireless communications. More specifically, the present invention relates to a novel and improved system and method that utilizes a broadcast addressing feature notification message to notify a user of a zone in which the user is currently located.

1 illustrates a system implementation of the present invention and illustrates the effect on a user crossing a boundary area with different zone boundaries.

2 is a flowchart illustrating a zone notification method.

The present invention is directed to a novel and improved system and method for notifying a user of zone information using a notification message of broadcast address characteristics. Optionally, the user can know the zone information using a short message service (SMS) message.

The base station periodically transmits a broadcast address characteristic notification or SMS message including a text message to inform the user of the zone to which the base station belongs. Phones in zones based on the progressive rate scheme are assigned specific broadcast addresses. All other phones using different calling methods are not assigned the same broadcast address. The telephone with the broadcast address may determine that the addressing information is to be delivered to the telephone. A phone without a broadcast address only discards the message. Therefore, the progressive toll type phone can continuously update the zone information for the user. There is no harm to a phone that is not subscribed to a progressive fee scheme. The system capacity on the access channel remains the same because there is no registration message of the telephone requested in response to the zone information message. The capacity on the paging channel is reduced only slightly and slightly at the level when the directional message is used. The use of broadcast messages is much more efficient than directional messages because broadcast messages allow a single transmission to multiple phones while allowing only one recipient during each transmission.

The features, objects, and advantages of the present invention will become more apparent from the following detailed description with reference to the drawings in which like reference numerals are used.

In CDMA wireless telephone systems operating in accordance with TIA / EIA / IS-95, there are several message formats that can be used to transfer information from a base station to a telephone. Two available message formats are Feature Notification Message and Short Message Service (SMS).

The feature notification message is sent from the base station to the telephone on the paging channel. One of the fields of the feature notification message causes the message to use broadcast addressing.

Broadcast addressing allows a base station to send a single message to multiple phones at the same time. Many phones can share the same broadcast address. The telephone provided is configured to receive a broadcast addressing message and is configured with a specific broadcast address and the telephone will process the message. This is in contrast to the directional message that the base station sends to the particular phone using the phone mobile station identification number.

The use of broadcast addressing is useful because a message can be delivered to multiple recipients and messages can only be delivered to individuals providing useful information. In the case of an area based on progressive charging, the toll-based phone is assigned a specific broadcast address that is not included in the toll-free phone. Progressive toll telephones will process zone identification messages sent using broadcast addressing. This is the opposite of asking the phone to register each time the phone crosses a zone boundary. Phone registration cannot be configured differently between phones in the same system. If every call is required to register every time a zone boundary is crossed, the wireless system will experience a significant reduction in capacity to provide an advantage for a small percentage of the total subscribers.

An advantage provided to subscribers of the progressive rate scheme is information identifying the area to which the call belongs. In addition to using broadcast addressing to convey the message, the feature notification message may be configured to provide a "display" record. Use of the "display" record indicates to the telephone that the content of the feature notification message is displayed in alphabetic characters on the telephone. The specific alphabetic message that each base station sends is zone information (for example, "you are in zone 3" or "welcome to downtown" or "city mall"). The user can then determine if a telephone call originating from a particular zone would result in an increase in toll. By sending a feature notification message, a telephone entering a zone is notified of a change in zone status. No transmission activity of the phone is required. In addition, because broadcast addressing is used, only the phones to which the message is directed will process and display the message.

Short Message Service (SMS) messages can be used as an option for feature notification messages. SMS messages are primarily used to convey alphabetic information to wireless telephones. General specifications for SMS in CDMA telephone systems are disclosed in the Telecommunications Industry Association and Telephone Industry Association specification TIA / EIA / IS-637 “Short Message Service for Broadband Spread Spectrum Cellular Systems”. The message can be initiated at the message center and sent to the telephone via the base station. The message may also be initiated at the telephone and sent via the base station to the message center. Only periodic transmission of zone information from the base station to the telephone needs to be considered.

The message sent from the base station to the telephone may be sent over a paging or traffic channel. The message sent to the telephone is formatted as a databurst message as defined in TIA / EIA / IS-95. As for the feature notification message, the message may be sent to an individual phone as a point-to-point directional message or may be sent simultaneously to multiple phones as a broadcast message.

The operation of the present invention is shown in FIG. 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 zone boundary 130. The second base station 120 provides coverage on the opposite side of the zone boundary 130. A number of elements, including each base station 110, 120, is not important to the illustration and is assumed to be implemented in the diagram showing each base station 110,120.

Zone boundaries 130 are described as randomly changing the curve to highlight the impossible places to define individual zone boundaries. Although the zone boundary 130 may be clearly defined in the system design, the actual zone boundary 130 varies depending on a number of factors including terrain, RF disturbances, and antenna patterns. User 140 operating mobile phone 141 within wireless system 100 coverage area will communicate with at least one base station 110 or 120 at any given time.

When the mobile phone 141 passes through the boundary area between the zones, the service area alternates between the first base station 110 and the second base station 120. For a given route 142 along the boundary area, the mobile phone 141 will cross the zone boundary several times. If the mobile phone 141 is in the service area defined by the first base station 110, the forward link 114 information and the reverse link 112 information are supported by the first base station 110. Similarly, once mobile phone 141 is in the service area defined by the second base station, corresponding forward link 124 and reverse link 122 channels are supported by second base station 120.

In the existing embodiment, the zone location of the mobile phone 141 is updated by requiring the mobile phone 141 to register each time the zone boundary 130 intersects. Each time mobile phone 141 crosses a zone boundary, system parameter messages received at mobile phone 141 are generated from different base stations. Referring to the situation presented in FIG. 1, initially the mobile phone 141 operates in the service area defined by the first base station. The system parameter message broadcast from the first base station identifies the zone within the first base station 110. First entering a zone and receiving a system parameter message on the forward link 114 paging channel, the mobile phone 141 sends a registration message on the reverse link 112 access channel to the first base station 110. The first base station 110 responds by sending a directed message to the mobile phone 141 containing the zone information on the paging channel. When mobile phone 141 moves along path 142 of the border area, the mobile phone crosses area border 130. When the mobile phone 141 crosses the zone boundary 130, the service area is provided by the second base station 120. The second base station 120 sends a system parameter message indicating a different zone. In response to this zone indication different from the zone in which the mobile phone 141 is already registered, the mobile phone sends another registration message to the second base station 120 via the reverse link 122 access channel. The second base station 120 then transmits a directivity message including the zone information to the mobile telephone 141. System parameter messages indicating zone changes, and subsequent mobile phone 141 registrations and directional message transmissions by the base station, are repeated each time mobile phone 141 crosses zone boundaries 130. If this registration scenario is multiplied by the number of phones crossing the zone boundary at a given time, the load on the wireless communication system becomes large.

Additional mobile phones 150 and 160 operating along zone boundary 130 will traverse independent paths 152 and 162 respectively. When mobile phone 150 crosses route 152, it crosses zone boundary 130 twice and is required to register each time it crosses boundary 130. Mobile phone 150 receives zone information in response to each registration. Similarly, each time crossing the zone boundary 130, the third mobile phone 160 crossing along the independent path 162 is required to initiate registration messages and receive a zone information response. Subsequent registration messages from the mobile phone 141 will reduce the access channel capacity, while numerous directional messages from the base station 110 or 120 will reduce the capacity of the paging channel.

Looking back at the situation in FIG. 1, the present invention does not require any transmission from the mobile phone 141. Instead, each base station 110 or 120 periodically sends an SMS message or broadcast addressing feature notification message that includes a display record for the zone information. The frequency at which the base station 110 or 120 repeats the feature notification message is determined by the system design and is generally in the range of 5-15 seconds. If mobile phone 141 is in a particular zone, the mobile phone receives and processes the feature notification message and displays zone information to the user. When the mobile phone 141 proceeds along the path 142 to the boundaries between the zones, the mobile phone 141 alternately receives feature notification messages from either the first base station 110 or the second base station 120. do. The feature notification message that mobile phone 141 receives and processes indicates the area in which the mobile phone currently exists. Mobile phone 141 does not need to make any transmission to be notified of the current zone. This reduces the load on the access channel and allows to conserve battery power in the phone. In addition, because the base stations can use broadcast addressed messages instead of directed messages, the load on the paging channel is reduced. Additional mobile phones 150 and 160 operating at the zone boundary provide no load on the system. Each base station 110 or 120 transmits a zone notification message regardless of the number of mobile phones 141, 150, and 160 crossing the zone boundary 130. Each mobile phone 141, 150, 160 displays an area notification message corresponding to the base station 110 or 120 providing the area service area.

The zone notification method is shown in FIG. Starting at 200, an area notification message is sent from the base station (204). The base station does not send a zone notification message in response to an event; rather, this message transmission is the only zone notification activity required for the base station. The base station implements this message as a broadcast directed message and sends these messages simultaneously to multiple telephones. At decision step 208, the limits of the base station service area cause the routine to proceed only if the mobile phone is within the service area. No device makes the decision, but rather the decision is made by physical service limits. If the telephone is not in the service area, the transmission signal is too weak to be received by the telephone. Thus the routine ends at 240. If there is a telephone in the service area, the telephone receives a zone notification message 210. At decision step 220 the phone checks to see if a message has been directed to that phone. This check is made by comparing the broadcast address of the zone notification message with the address stored in the phone. If the broadcast address does not match the address stored in the phone, the phone determines that the message has not been assigned to it. Thus, the phone discards the message 230 and the routine ends 240. However, if the broadcast address matches the address stored inside the phone, the phone processes the message (224) and displays the text component of the message to the user (228). If the method of Fig. 2 is repeated periodically, each telephone in the base station service area is constantly updated with the correct zone information.

While the foregoing has been described in terms of preferred embodiments, this is merely an example to facilitate the description, and the skilled artisan will appreciate that the present invention is not limited to these and various modifications are possible.

Claims (13)

A wireless communication system used to inform a user that a user is located within a predetermined area, A plurality of base stations defining a plurality of predetermined zones each including one or more base stations; A plurality of mobile units capable of moving between said predetermined zones; Each base station transmits a zone information message corresponding to a predetermined zone in which the base station is located, wherein each mobile unit is located in a zone by receiving and processing zone information messages from the base station with which the mobile unit is currently communicating. A wireless communication system providing a user indication indicating that. The wireless communication system of claim 1, wherein each base station transmits the zone information message periodically. 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 uses broadcast addressing and display record type. 5. A wireless communication system according to claim 4, wherein the user indication that the user is located in the zone is the content of the feature notification message display record. The wireless communication system of claim 1, wherein the zone information message is a short message service (SMS) message. A method of informing a plurality of wireless telephone users that they are located within a predetermined zone, Transmitting a zone information message from a base station; Receiving the zone information message at the wireless telephone; Processing the zone information message at the wireless telephone; Instructing the wireless telephone user a location of a zone corresponding to a content of the zone information message. 8. The method of claim 7, wherein the transmitting step, the receiving step, the processing step and the indicating step are repeated periodically. 8. 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 step of instructing is performed only if the wireless telephone has the same broadcast address as used in the feature notification message. 8. The method of claim 7, wherein the zone information message is a short message service (SMS) message.