|Title of Invention||
A METHOD OF INFORMING A PLURALITY OF WIRELESS PHONE USERS OF PRESENCE WITHIN A PRE-DETERMINED ZONE.
|Abstract||The present invention relates to a system and method for identifying user zone using broadcast addressed notification messages. 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.|
|Full Text||SYSTEM AND METHOD FOR IDENTIFYING USER ZONE USING BROADCAST ADDRESSED NOTIFICATION
BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to wireless communications. More particularly, the present invention relates to a novel and improved system and method for using broad Cast addressed feature notification messages to notify a wireless device user of the zone that they currently are in.
II- Description of the Related Art
In a wireless communication system, such as a cellular or Personal Communications Services (PCS) phone system, the system is physically divided into numerous coverage areas. Coverage areas may be defined by both physical and non-physical constraints. A coverage area defined by identity of service provider is an example of a non-physical constraint, whereas the coverage area defined by a single base station transceiver (i.e. a cell) is physically constrained by geography, transmitter power, and receiver sensitivity. A service provider divides its service area into numerous smaller zones. Each zone encompasses at a minimum the cell defined by a single base station transceiver and likely encompasses a number of cells. The size of each zone is denned by the service provider at the time of system design.
Coverage areas defined by the identity of the service provider are important for billing purposes. The service provider that assigns a telephone number and provides billing to a particular wireless device is designated the home service provider for that device. When a wireless device is used outside of its service provider"s coverage area it is considered to be roaming. The cost of a roaming phone call is typically higher than the cost of a phone call within the home service provider"s system. Because of the cost differential between home and roaming calls a wireless device uses
overhead information transmitted 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 a phone displa.y to inform the user of the roaming condition.
The same home/roaming concept can be used within a service provider"s coverage area. The division of service provider coverage areas into distinct zones provides for the opportunity for the service provider to offer zone based progressive rate plans. In such a plan the wireless telephone user would pay progressively higher calling rates as the distance (measured in number of zones) from a predetermined home zone increases. This zone based progressive rate plan is analogous to the billing practice used by Public Switched Telephone Network (PSTN) service providers. However, unlike the case of the PSTN where the call rate is based on the zone of the called number, the rate of a call from a zone based wireless telephone is based on the zone in which the wireless telephone is originating the call.
One problem experienced by wireless telephone users that. Public Switched Telephone Network (PSTN) phone users don"t experience derives from the mobility of the wireless phone. The mobility of the wireless phone makes critical the real time determination of the zone location of the wireless phone. When a wireless phone initiates a call, and as the call continues, the zone in which the wireless phone resides must be determined. The wireless phone may move from zone to zone during the course of a single call.
A possible solution requires the wireless phone to register with the system each time the phone crosses a zone boundary. In response to the phone registration message the base station responds with a message to the registering phone telling it what zone it is in. Every wireless phone system, regardless of modulation type, has some provision for mobile phone registration. The Code Division Multiple Access (CDN"tA) cellular system interface is specified in Telecommunications Industry Association (TIA) and Electronic Industries Association (EIA) interim standard TIA/EIA/IS-95
MOBILE STATIO.NI-BASE STATION COMPATIBILITY STANDARD FOR DUAL-MODE SPREAD SPECTRUM SYSTEMS.
As defined in TlA/ELA/IS-95 a CDMA cellular phone has multiple registration modes. The standard defines nine different regi.srration methods supported in a CDMA system. The different forms of registration are Power Up, Power Down, Timer Based, Distance Based, Zone Based, Ordered, Traffic Channel, Parameter Change, and Implicit.
In a CDMA system each base station periodically sends overhead messages on a Paging Channel to any phone within its coverage area. The overhead information is sent to the phones as a System Parameters Message and includes System Identification (STD) numbers and Network Identification (NID) numbers. From these two numbers a phone can determine whether or not it is within the coverage of its home system. A phone not in the home coverage area is considered to be roaming. The phone displays the roaming status to the user since charges incurred for roaming phone calls are typically higher than for the same phone call made from a home system.
Additionally, the System Parameters Message includes a data field for a Registration Zone. The Registration Zone in conjunction with the SID and NID numbers can trigger a mobile phone zone based registration. The phone stores a list of zones, ZON"E.LIST, in v/hich it has registered. The number of zones stored in ZONE_LIST is a variable that can be set by a data field in the System Parameters Message. The phone compares the SID, NID, and Registration Zone information received in the System Parameters Message with the entries in the ZONE_LIST. If the SID, NTD, and Registration Zone information is not already stored in the ZONE_LIST the phone initiates a registradon on the Access Channel.
The ZONE_LIST is kept current by initiating a zone list timer for every entry in the ZON^E.LIST. When the timer expires for any particular entry in the ZONE_LIST the entry is removed from the list. Similarly, if the information received in the Systems Parameter Message indicate a new zone and the maximum number of zones already exists in the ZONE_LIST
the phone will use the zone list timers to determine the oldest entry and delete it from the list.
Zone based registration is particularjy useful m maxiriiizing the capacity" of the Paging Channels. A paging message can be directed to a phone using only those base stations in which the phone has recently registered. This maximizes system resources by eliminating the need to broadcast the paging message across all base stations just to ensure a single user receives the paging message.
General zone based registration can be modified to alJoiv zone information to be transmitted to the phone whenc\"er the phone enters a zone. In order to accomplish this the system needs to be configured such that the number of entries maintained in the ZONE_LIST is limited to one. This ensures the phone initiates a registration message whenever it crosses a zone boundary. In response to the phone registration the base station sends a directed message to the registering phone informing the user of the zone status. This directed message would be a text message to be displayed to the user. The user would then always know the current zone status and would presumably know what the corresponding billing rate is in that zone.
However, there are numerous disadvantages with configuring a system in this way. Since the number of entries in the phone 20NE_LIST is reduced to one the number of times a phone has to register in a system will increase. The increase in the number of registration messages sent by the phone is most evident when the phone is operating in a border region between two zones. When the phone is operating in a border region it will likely cross between the coverage area of the two zones numerous times. Since the number of entries in the ZONE LIST is restricted to one the phone is required to transmit a registration message each time the phone receives a System Parameters Message indicating a different zone. The effect is to greatly increase the number of tinies the phone is required to transmit a registration message. The increase in the number of transmitted registration messages results in a depletion of the battery energy in the phone thereby reducing the available standby and talk times of the phone. Many phones continually sending" registration messages have the effect of
over burdening the Access Channel. Where the zone boundaries occur on a major thoroughfare there is the problem of a large number of phones overloadii\g the Access Channel with effectively simultaneous registrytion messages.
Additionally, each registration message triggers a complementary directed message informing the registering phone of the zone. The directed messages, by their very definition, are sent to individual phones. The number of directed messages is greatly increased with the current planned method of informing phone users of zone information. This results in a loss of capacity on the Paging Channels.
The loss in Access Channel and Paging Channel capacity is not balanced by the user benefit of knowing which zone they are currently in. Furthermore, if the zone based progressive rate plan is only used by a small minority of subscribers supported by the service provider the system and a majority of subscribers are heavily penalized to benefit a small group of users. Each phone user has less phone talk time and standby time because of the increased number of registration messages required of the phone^ yet the complementary received zone information is helpful only to a small number of progressive rate plan subscribers.
What is required is a system and method of notifying those users on the progressive rate calling plan of the zone information without penalizing the wireless system or the users not on the same calling plan.
SUMMARY OF THE INVENTION
The present invention is a novel and improved system and method for notifying users of zone information using broadcast addressed feature notification messages. Alternatively, the user can be informed of zone information using Short Message Services (SMS) messages.
A base station periodically transmits broadcast addressed feature notification or SMS messages containing a text message that informs the user of the zone that the base station is within. Phones that are on a zone based progressive rate plan are assigned specific broadcast addresses. All
other phones using other calling plans are not assigned the same broadcast address. The phones with the broadcast address are able to determine that the addressed information is directed to that phone. Phones without the broadcast address merely discard the message. Therefore, phones on the progressive rate plan are able to continually update the zone information to the user. There is no detrimental effect to tliose phones not subscribed to die progressive rate plan. System capacity on the Access Cha.nnel is maintained since there are no registration messages required of fne phones jn reply to the zone information messages. The capacity on the Paging Channel is only decreased by a nominal amount and is decreased nowhere near the level when directed messaging is used. The use of broadcast messaging is much more efi^icient than directed messages since broadcast messaging allows a single transmission to be directed to m.any phones while directed messaging only allows one recipient for each transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
The features, objects, 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. } is a drawing depicting a system implementation of the invention and showing varying zone boundaries and effects on users traveling in a border area; and
FIG. 2 is a flow chart illustrating the zone notification method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a CDMA wireless phone system operating in accordance with TIA/EIA/I5-95 there are several messaging formats that can be used to send information from a base station to phones. Two such available messaging formats are Feature Notification Messages and Short Message Services (SMS).
Feature Notification Messages are sent from the base station to the phone on the Paging Channel. One of the fields in the Feature .Notifi:a:ion Message allows the message to utilize broadcast addressing.
Broadcast addressing allows the base station to simultaneously direct a single message to many hones. Many phones can share the same broadcast address. Provided the phone is configured to receive breakfast addressed messages and is configured with the particular broadcast address the phone will process the message. Thi is in contrast to directed messages that the base station sends to a particular phone using a phone Mobile Station Identification number.
The use of broadcast addressing is advantageous because one message can be directed to many ecipients and because messages can be directed only to those individuals for which the message provides useful information. In the case oi zone based progressive rate billing those phones on the rate plan are assigned a particular broadcast address that are not included ir, any phone not on the rate plan. Only those phones on the progressive rate plan will process zone identification messages transmitted using broadcast addressing. This is in contrast to the method requiring a phone to register each time it crosses a zone boundary. Phone registration cannot be configured differently among phones within the same system. If all phones are required to register v/henever a zone boundary is crossed, the wireless system suffers a significant reduction in capacity to provide a benefit for a small percentage of total subscribers.
The benefit provided to the subscribers of a progressive rate plan is information identifying the zone the phone is in. In addition to utilizing broadcast addressing to direct the message, the Feature Notification Message can be configured to provide a "display" record. The use of a "display" record indicates to the phone that the contents of the Feature Notification Message are alphanumeric characters to be displayed on the phone. The particular alphanumeric message each base station transmits is the zone information (e.g. "You are in zone 3." or "Welcome to downtown" or "Ciiy Mall" etc.) The user is then able to determine whether a phone call initiated from that particular zone would mcur an increased charge. By periodicaliv
transmitting the Feature Notification Message nny phone entering the zone is notified of a change in zone status. No transmit activity is required of the phone. Furthermore, since broadcast addressing is used, only those phones for which the message is intended will process and display the message.
Short Message Services (SMS) messages can be used ns an alternative to Feature Notification Messages. SMS messages are primarily used to communicate alphanumeric information to wireless phones. The general specification for SMS Ln a CDMA phone system can be found in Telecommunications Industry Association and Electronic Industries Association specification TL\/EIA/IS-637, SHORT MESSAGE SERVICES FOR WIDEBAND SPREAD SPECTRUM CELLULAR SYSTEMS- Messages may be initiated at a message center and transmitted via the base station to the phone. Messages may also be initiated at the phone and transmitted to the message center through the base station. Here the oiily concern is the periodic transmission of zone information from the base station to the phone
Messages transmitted from the base station to the phone may be transmitted over the Paging or Traffic channels. The messages transmitted to the phone are formatted as Data Burst Messages as defined in TIA/EIA/IS-95. As in the case of Feature Notification Messages, messages may either be sent to individual phones as point-to-point directed messages or may be simultaneously sent to many phones as broadcast messages.
Operation of the invention is illustrated in FIG. 1. Referring to FIG. 1 a portion of a wireless system 100 is shown. A first base station 110 provides coverage on one side of a zone boundary 130. A second base station 120 provides coverage on the opposite side of the zone boundary 130. The numerous elements comprising each base station, 110 or 120, are not critical to this illustration so are assumed to be embodied within the figure representing each base station, 110 and 120.
The zone boundary 130 is depicted as a randomly varying curve to lighlight the inability to define discrete zone boundaries. Although a zone coundary 130 may be distinctly defined in a system design, the actual zone coundary 130 varies due to numerous factors including terrain, RF
obstructions, and antenna patterns. A user 140 operating a mobile phone 141 within the service area of the wireless system 100 will be in communication with at least one base station, 110 or 120, at any given time.
When the mobile phone 141 moves through a boundary r.re? between zones the coverage will alternate between a first base station 110 and a second base station 120. For a given path 142 along the boundary area the mobile phone 141 will cross the zone boundary 130 a number of times. When the mobile phone 141 is in tine coverage area defined by the first base station 110 both forvvaxd link 114 information and reverse link 112 information will be supported by the first base station 110. Similarly, when the mobile phone 141 is in the coverage area defined by tlie second base station 120 the corresponding forward link 124 and reverse link 122 channels are supported by the second base station 120.
Under an existing embodiment the mobile phone"s 141 zone location is updated by requiring the mobile phone 141 to register each time a zone boundary 130 is crossed. Each time the mobile phone 141 crosses the zone boundary 130 the System Parameters Message received at the mobile phone 141 will originate from a different base station. Taking the situation illustrated in FIG. 1, the mobile phone 141 initially is operating in the coverage area defined by the first base station 110. The System Parameters Message broadcast from the first base station 110 identifies the zone that the first base station 110 is within. Upon first entering the zone and receiving the Systems 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, on the Paging Channel, a directed message containing zone information to the mobile phone 141. As the mobile phone 141 travels along a path 142 in a border region it crosses the zone boundary 130. Once the mobile phone 141 crosses the zone boundary 130 the coverage is now provided by a second base station 120. The second base station 120 sends out a System Parameters Message indicating a different zone. In response to the indication of a zone different from the one the mobile phone 141 is already registered in, the mobile phone initiates another registration message on the
reverse link 122 Access Chcinnel to the second base station 120. In return, the second base station 120 sends a directed message containing zone information to the mobile phone 141. This scenario of a System Parameters Message indication of a chajige of zones Ibllowed by mobile phone 141 registration and base station transmission of a directed message is repeated each time the mobile phone 141 crosses the zone boundar}" 130. When the registration scenario is multiplied by the number of phones crossing a zone boundary at any given time, it can be seen that the load presented to the vv"ireless system is considerable-
Additional mobile phones 150 and 160 operating along the zone boundary 130 vvill traverse independent paths 152 and 162 respectively. As the mobile phone 150 traverses path 152 it will cross the zone boundary 130 two times and will be required to register each time it crosses the boundary 130. The mobile phone 150 will receive zone information in response to each registration. Likewise, a third mobile phone 160 traversing along an independent path 162 will be required to initiate registration messages and will receive zone information replies each time it crosses the zone boundar}" 130. The constant registration messages from the mobile phones 141 decrease the capacity of the Access Channel while the numerous directed messages from the base statior\s, 110 or 120, reduce the capacity of the Paging Channel.
Revisiting the conditions of FIG. 1 with the present invention implemented in the system, it can be seen that the present invention requires no transmissioris from the mobile phone 141. Instead, each base station, 110 or 120, periodically transmits a broadcast addressed Feature Notification Message or SMS message containing a display record with the zone information. The period that the base station 110 or 120 repeats the Feature Notification Message is determined at system design and is t>"pically in the range of 5 -15 seconds. When the mobile phone 141 is in a particular zone it receives and processes the Feature Notification Message and displays the zone information to the user. As the mobile phone 141 proceeds along a path 142 on a boundary between zones the mobile phone 141 alternately receives a Feature Notification Message from either the first base station 110
oi the second base station 3 20. The Feature Notification Message tht; mobile phone 141 receives and processes corresponds to the zone in uhich it currently resides. The mobile phone 141 is not required to make any active transmissions in order to be notified of the current zone. Thi.s reduces the load on the Access Channels and conserves battery power within the phone. Additionally, since the base stations 110 and 120 are able to use broadcast addressed messages instead of directed messages the load on the Pa;5ing Channels is reduced. It can be seen that additional mobile phones 150 and 160 operating in the zone boujidary provide no increased load on the system. Each base station 110 or 120 transmits a zone notification message independent of the number of mobile phones 141, 150, and 160 crossing the zone boundary 130. Each mobile phone 141,150, and 160 displays the zone notification message corresponding to the base station 110 or 120 providing the zone coverage.
The zone notification method is summarized in FIG. 2. After starting 200 the method the zone notification message is transmitted from the base station 204. The base station does not transmit the zone notification message in response to an event, rather the transmission of the message is . the sole zone notification activity required of the base station. The base station configxires the message as a broadcast addressed message to simultaneously direct the message to multiple phones. At decision step 20S, the limitations of the base station coverage area effectively allow the routine to proceed only if a phone is within the coverage area. No device actually performs the decision, rather the decision is made by the physical coverage limitations. If a phone is not within the coverage area of the transmitting base station the transmitted siimal will be too weak to be received bv any phone. Therefore the routine ends 240. If there is a phone within the coverage area the phone receives the zone notification message 210. At decision step 220 the phone checks to see if the message was directed to that phone. This check is done by comparing the broadcast address of the zone notification message against predetermined addresses saved within the phone. If the broadcast address is not one saved within the phone, the phone determines that the message was not directed to it. Therefore the
phone discards the message 230 and the routine 240. However, if the broadcast address coincides with an address saved within 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 on a periodic basis each phone within the coverage area of the base station will be continually updated with the correct zone information.
The previous description of the preferred embodiments is provided to enable any person skied in the art to make or use the present invention. The 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.
WE CLAIM :
1. A method for informing a plurality of wireless phone users of presence within
a predetermined zone comprising the steps:
transmitting from a base station a zone information message;
receiving at the wireless phone the zone information message; processing the zone information message within the wireless phone; and
indicating to the wireless phone user a zone presence corresponding to contents of the zone information message.
2. The method as claimed in Claim 1 wherein the steps are repeated periodically.
3. The method as claimed in Claim 1 wherein the zone information message is a Feature Notification Message.
4. The method as claimed in Claim 1 wherein the Feature Notification Message is broadcast addressed.
5. The method as claimed in Claim 1 wherein the Feature Notification Message defines a display record type.
6. The method as claimed in Claim 1 wherein the indicating step is performed only if the wireless phone has the same broadcast address as used in the Feature Notification Message.
7. The method as claimed in Claim 1 wherein the zone information message is a Short Message Services (SMS) message.
8. A wireless communication system to inform users of presence within a predetermined zone by the method claimed in claims 1-7.
|Indian Patent Application Number||IN/PCT/2002/251/CHE|
|PG Journal Number||05/2007|
|Date of Filing||15-Feb-2002|
|Name of Patentee||M/S. QUALCOMM INCORPORATED|
|Applicant Address||5775 Morehouse Drive San Diego, CA 92121-1714|
|PCT International Classification Number||H04Q 7/38|
|PCT International Application Number||PCT/US00/22730|
|PCT International Filing date||2000-08-16|