WO2001095505A2

WO2001095505A2 - Method and apparatus for providing a location of a communication device in a wireless communication system

Info

Publication number: WO2001095505A2
Application number: PCT/US2001/017539
Authority: WO
Inventors: Scott Droste
Original assignee: Motorola Inc.
Priority date: 2000-06-05
Filing date: 2001-05-31
Publication date: 2001-12-13
Also published as: AU2001265227A1; WO2001095505A3

Abstract

A location tracking service is provided whereby a user of a communication device may determine a geographical location of a subscribing customer (110) of the service. The user conveys a request to the service (108) that the service determine a location of the subscribing customer (110). In response to receiving the request, the service (108) prompts the user to provide a subscribing customer identifier. Based on the provided subscribing customer identifier, the service determines a geographical location of the subscribing customer (110) by determining a geographical location of a communication device of the subscribing customer (110), and conveys the determined geographical location to the user. The service is also capable of providing to the user the length of time that the subscribing customer (110) has been positioned at the determined geographical location and a direction of movement of the subscribing customer (110).

Description

METHOD AND APPARATUS FOR PROVIDING A LOCATION OF A COMMUNICATION DEVICE IN A WIRELESS COMMUNICATION

SYSTEM

Field of the Invention

The present invention relates generally to communication systems and, in particular, to providing a location of a communication device in a wireless communication system.

Background of the Invention

Wireless communication systems are known in which a communication device, such as a mobile or a portable radio, wirelessly communicates with a fixed infrastructure comprising multiple geographically-diverse cell sites. Each cell site comprises one or more base stations along with other items of equipment. The enactment of E911 requirements for wireless communication systems also means that in the future, wireless systems will be required to include a capability to determine a geographical location of the communication device. The inclusion of such capabilities in wireless communication systems opens up new vistas for services that can be offered by wireless communication carriers.

Currently, it is well known that a consumer, such as a homeowner, who makes a home appointment with a service provider such as a housing subcontractor (e.g., an electrician or a plumber), a cable TV installer, or a telephone company installer, is assigned an ambiguous block of time, such as an entire morning or an entire afternoon, for an appointment with the service provider at the consumer's home. During the assigned block of time, the consumer has little alternative but to wait patiently for the arrival of the service provider. If the consumer decides to leave his or her home during the assigned period of time, for example to run a quick errand, the consumer risks missing an arrival of the service provider, having to reschedule the appointment, and having wasted the time already spent waiting. As a result, the consumer is restricted to home while awaiting the arrival of the service provider, while the service provider could be miles away from the consumer's home or tied up with an earlier scheduled job. Therefore, a need exists for a method and apparatus that allows a consumer to determine a current location of a service provider and to estimate a time of arrival of the service provider.

Brief Description of the Drawings

FIG. 1 is a block diagram of a communication system in accordance with a preferred embodiment of the present invention.

FIG. 2 is a block diagram of a cell site of FIG. 1 in accordance with a preferred embodiment of the present invention.

FIG. 3 is a block diagram of a communication device of FIG. 1 in accordance with a preferred embodiment of the present invention.

FIG. 4 is a block diagram of a location tracking service platform of FIG. 1 in accordance with a preferred embodiment of the present invention. FIG. 5 is a logic flow diagram of steps executed by a location tracking service for providing a location of a communication device in accordance with a preferred embodiment of the present invention.

FIG. 6 is a logic flow diagram of steps executed by a location tracking service for providing a location of a communication device in accordance with an alternative embodiment of the present invention.

FIG. 7 is a logic flow diagram of steps executed by a location tracking service for providing a location of a communication device in accordance with an alternative embodiment of the present invention.

Detailed Description of the Invention

To address the need for a method and apparatus that allows a consumer to determine a current location of a service provider and to estimate a time of arrival of the service provider, the present invention provides a location tracking service whereby a user of a communication device may determine a geographical location of a subscribing customer of the service. The user conveys a request to the service that the service determine a location of the subscribing customer. In response to receiving the request, the service prompts the user to provide a subscribing customer identifier. Based on the provided subscribing customer identifier, the service determines a geographical location of the subscribing customer by determining a geographical location of a communication device of the subscribing customer, and conveys the determined geographical location to the user. The service is also capable of providing to the user the length of time that the subscribing customer has been positioned at the determined geographical location and a direction of movement of the subscribing customer.

Generally, the present invention provides a method for providing a location of a communication device in a wireless communication system. The method includes steps of receiving a request for a geographical location from a user of an originating communication device and requesting a subscribing customer identifier in response to receiving the request for a geographical location. The method further includes steps of receiving a subscribing customer identifier in response to requesting the subscribing customer identifier and authenticating the subscribing customer identifier. The method further includes steps of determining a geographical location of a subscribing customer communication device and conveying the determined geographical location to the user of the originating communication device.

Another embodiment of the present invention encompasses an apparatus that includes a processor coupled to a speech processing unit for providing a location of a communication device in a wireless communication system. The processor receives a request for a geographical location from a calling party, instructs a speech processing unit to request a subscribing customer identifier in response to receiving the request for a geographical location, and receives a subscribing customer identifier in response to requesting the identifier. The processor further determines a geographical location of the communication device and conveys the determined geographical location to the calling party via the speech processing unit. The speech processing unit prompts the calling party to provide a subscribing customer identifier in response to an instruction received from the processor and conveys the determined geographical location to the calling party based on a message comprising the determined geographical location that is received from the processor.

Finally, another embodiment of the present invention encompasses an apparatus including a processor for providing a location of a communication device in a wireless communication system. The processor receives a request for a geographical location from a user of an originating communication device, requests a subscribing customer identifier in response to receiving the request for a geographical location, and receives a subscribing customer identifier in response to requesting the identifier. The processor further determines a geographical location of a subscribing customer communication device and conveys the determined geographical location to the user of the originating communication device.

The present invention can be more fully understood with reference to FIGs. 1-6. FIG. 1 is a block diagram of a communication system 100 in accordance with a preferred embodiment of the present invention.

Communication system 100 includes a wireless communication system 150 that includes multiple geographically-diverse cell sites 101-103 (three shown) that are coupled to each other, to a system controller 104, to a location database 106, to a mobile switching center (MSC) 114 and to a location tracking service platform 108 via a network 116, such as dedicated Tl phone lines or microwave links. Location database 106 preferably includes a memory device, such as a random access memory (RAM), that stores a database of the locations of all cell sites 101- 103 in system 150. Alternatively, location database 106 may be included in a memory of system controller 104 or a memory of any of base sites 101-103. System controller 104 comprises memory and a processor that allows the controller to store data and make computations, among other things. Cell sites 101-103, system controller 104, location database 106, location tracking service platform 108, and network 116 are collectively referred to as a fixed infrastructure. Being fixed in place, the precise location of each cell site 101-103 is known with high accuracy as determined by surveying or other methods of geographic location determination.

MSC 114 preferably is a digital multiplex switch-mobile switching center, such as a "EMX2500"digital multiplex switch-mobile switching center that is commercially available from Northern Telecom. MSC 114 includes a digital switching matrix that provides basic switching functionality for incoming and outgoing telephone calls in system 150 and a processor coupled to the digital switching matrix that controls the switching. Cell sites 101-103 each preferably is an "SC9600"base station and controller that is commercially available from Motorola, Inc. of Schaumburg, Illinois. Each cell site 101-103 provides communication services to a respective service coverage area 111-113. As shown in FIG. 2, each of cell sites 101-103 preferably includes a transmitter 200 and a receiver 202 coupled to a processor 204. Processor 204 and an associated memory 206 allow the respective cell site 101-103 to store information, make computations, and run software programs. Further coupled to processor 204 is a controller 208 and a timing reference unit 210 that provides a timing reference for the cell site 101-103. In the preferred embodiment, cell sites 101-103 further include a Global Positioning Satellite (GPS) receiver 210 that is coupled to timing reference unit 208. System 150 further includes multiple communication devices 110, only one of which is shown in FIG. 1. Communication device 110 preferably comprises a cellular telephone and, as shown in FIG. 3 preferably includes a radio frequency transmitter 304 and a radio frequency receiver 306 that are each coupled to an antenna 302 and to a controller 308, such as a microprocessor for operating the communication device 110. Controller 308 operates according to an instruction code stored in an associated memory 310.

As communication device 110 roams throughout the system 150, system controller 104 assigns a cell site (e.g., cell site 101) to serve as a serving cell site for the communication device 110. The serving cell site 101 manages and provides communication services for the communication device 110 while the communication device is located in the serving cell site's service coverage area 111.

Cell sites 101-103 have access to a common time base which each cell site 101-103 uses to synchronize its timing reference unit 208. In the preferred embodiment, the common time base is provided by the GPS receiver 210 at each cell site 101-103, which GPS receiver 210 has access to a GPS satellite signal. Those of ordinary skill in the art will appreciate that there are other methods of supplying a highly accurate common time base to the cell sites 101-103, such as a synchronization unit that is connected to the cell sites via a dedicated Tl link that is a part of the network 116 and that is dedicated to time synchronization, which synchronization unit generates a common time base and supplies the common time base to the cell sites via the Tl link. Accordingly, such other methods of supplying a common time base may be used without departing from the spirit and scope of the present invention. The fixed infrastructure is typically connected to a Public Switched Telephone Network (PSTN) 120 through a communication link 118, such as a frame relay link. Communication link 118 allows communication device 110 to communicate over PSTN 120. In the preferred embodiment, an external call initiated from an originating communication device 122, such as a conventional telephone, connected to PSTN 120 is directed toward a location tracking service. PSTN 120 will send the call notification and source identification information over communication link 118 to wireless communication system 150, where the fixed infrastructure will forward the call to a location tracking service platform 108 and reserve a communication channel for communication with originating communication device 122.

In an alternative embodiment of the present invention, the originating communication device may be another wireless communication device 130, such as cellular telephone, in communication with PSTN 120 via a cell site 132 and an MSC 134. Cell site 132 is a serving site that provides communication services to communication device 130. The serving site modulates data and voice messages received from PSTN 120 via MSC 134 to RF signals for transmission to communication device 130 and demodulates RF signals received from the communication device for subsequent routing to PSTN 120. In another alternative embodiment of the present invention, the originating communication device may be data terminal equipment (DTE) 140, such as a personal computer or a workstation, or a telephone 142 that includes a data modem and is coupled to PSTN 120 via a data network 144 such as the Internet.

In the preferred embodiment, wireless communication system 150 is operated by a wireless communication system carrier. The present invention provides a location tracking service that the wireless carrier has available for each customer of system 150. When a customer, such as a home service provider such as an electrician, plumber, cable TV installer, or a telephone installer, subscribes to the location tracking service, the wireless carrier assigns the subscribing customer a unique subscribing customer identifier, or location access code (LAC). The location tracking service then allows a calling party, such as a consumer of the services of the service provider, to obtain a location of a communication device of the subscribing customer (e.g., communication device 110), or service provider, at any time by dialing a predetermined telephone number and providing the LAC. The LAC is provided to the calling party by the service provider. In response to receiving the LAC, the service provides the calling party with the service provider's geographical location. Based on the provided location, the calling party is then able to make an informed decision of how best to utilize the time remaining before the arrival of the service provider at the calling party's home.

In the preferred embodiment, the operation of a location tracking service is as follows. A calling party originates a telephone call from an originating communication device 122 to a location tracking service platform 108 by dialing a predetermined telephone number, preferably a toll-free, or "800," number (i.e., 800- or 888-xxx-xxxx). The predetermined number corresponds to a request to use a location tracking service. The telephone call is received by a local exchange carrier (LEG) switch in PSTN 120. The LEC switch examines the dialed number, recognizes that the dialed number is a toll-free number and that this is a toll-free call, and performs a conventional query of a national toll-free number database connected to the LEC switch to determine the appropriate telecommunications services carrier associated with the dialed number. Based upon the dialed number and a wireless communication system carrier determined with reference to the national toll-free number database, PSTN 120 routes the call to communication system 150 and establishes a communications circuit between originating communication device 122 and system 150 in accordance with well known techniques. PSTN 120 also transmits the dialed "800" number to system 150. When the call is received in system 150, the call is routed to MSC 114. MSC 114 performs a conventional query of a routing database 113 coupled to MSC 114 to determine routing information for the telephone call based on the dialed number. Routing database 113 includes a listing of system services, such as a location tracking service, a predetermined telephone number associated with each service, and routing information corresponding to each service. Based on the dialed telephone number, database 113 returns to MSC 114 routing information for the telephone call. MSC 114 then routes the call to location tracking service platform 108 based on the routing information and establishes a communication circuit between PSTN 120 and location tracking services platform 108. MSC 114 also transmits the dialed "800" number to platform 108. FIG. 4 is a block diagram of location tracking service platform 108 in accordance with a preferred embodiment of the present invention. Location tracking service platform 108 is arranged to perform various telephone services such as playing announcements, performing database operations based on received information, and call completion. Service platform 108 includes a conventional voice processing system, including a processor 402 and a memory 404 coupled to the processor that operate under the control of stored programs. Processor 402 and other modules 406-408,416 in service platform 108 are interconnected via a common bus 420. The other modules 406-408, 416 include a dual-tone multi-frequency (DTMF) receiver 406, arranged to respond to "touch tone" signals, and a speech processing unit 408 that can both generate voice prompts (announcements) and respond to voice inputs. Speech processing unit 408 includes a voice generator 410 for playing various phrases to a calling party accessing system 150 based upon a vocabulary stored in associated random access memory (RAM) 412, and a voice response unit 414 for receiving and interpreting speech input received from the customer.

Call completion is handled in location tracking service platform 108 using a switch module 416 that is controlled by processor 402. Switch module 416 has the ability to connect incoming calls to DTMF receiver 406, speech processing unit 408, or the other location tracking service platform modules. Switch module 416 also can connect or bridge incoming circuits to available outgoing circuits, so that a given incoming call can be completed to a specified destination, based upon stored information in service platform 108. To support this capability, switch module 416 is also arranged to couple each of modules 402, 406-408 in applications platform 108 to the outgoing circuits via an interface module 418, so as to provide signaling to MSC 114 and system controller 104 and, via MSC 114 and system controller 104, to other elements of telecommunication system 150. When the call is received by location tracking service platform 108, the dialed "800" number is available. The dialed "800" number corresponds to a location tracking service request and is recognized as such by processor 402. Location tracking service platform 108 prompts the calling party to provide a location access code, preferably by entering an alphanumeric sequence, that is unique to the subscribing party. The prompt is generated by voice generator 410 pursμant to an instruction received from processor 402. Voice generator 410 calls up an appropriate announcement that is digitally stored in RAM 412, converts the announcement to an audio signal, and then transmits the audio version of the announcement to the calling party.

In response to the announcement, the calling party enters a LAC that has been provided to the calling party by a subscribing customer. Preferably the LAC is a sequence of sequence of numbers or symbols (the LAC) that are entered by the calling party into originating communication device 122 via the device's keypad. Communication device 122 converts the entered LAC into a sequence of DTMF signals that are routed to location tracking service platform 108 and therein by switch module 416 to DTMF receiver 406. DTMF receiver 406 extracts the entered numbers or symbols from the received DTMF signals and transmits the numbers to processor 402. Processor 402 then searches memory 404 to authenticate the calling party, that is, to determine whether the LAC is valid. In an alternative embodiment of the present invention, the LAC may be verbally entered by the calling party into originating communication device 122 instead of being entered via the device's keypad. In the alternative embodiment, processor 402, when awaiting the LAC, monitors signals received from originating communication device 102 for voice signals as well as DTMF tones. Upon receiving voice signals, processor 402 directs the voice signals to voice response unit 414. Voice response unit 414 determines each alphanumeric character included in the voice signals and generates digital data corresponding to each alphanumeric character. Voice response unit 414 then conveys the digital data to processor 402, and processor 402 searches memory 404 to authenticate the LAC based on the digital data. Memory 404 stores information in the form of a profile for each customer that subscribes to the location tracking service. Each customer profile includes a LAC assigned to the subscribing customer and a communication device identifier, preferably a numerical sequence, that is uniquely associated with the customer's communication device (i.e., communication device 110). Processor 402 authenticates the LAC by locating the LAC in memory 404.

When processor 402 fails to locate the LAC in memory 404, processor 402 conveys a message, preferably an announcement that is generated by voice generator 410 in response to an instruction received from processor 402, to the calling party indicating that the LAC is invalid. Processor 402 may then terminate the telephone call or again prompt the calling party to enter a valid LAC. The number of times that processor 402 prompts the calling party to enter a valid LAC before terminating the call is up to the designer of the location tracking service.

When the LAC is located and authenticated by processor 402, memory 404 returns to processor 402 the information stored in a subscribing customer profile that corresponds to the LAC. Processor 402 then determines a geographical location of the subscribing customer by determining a geographical location of the subscribing customer's communication device (i.e., communication device 110). Processor 402 determines a geographical location of communication device 110 by conveying a request to system controller 104 that system 150 determine the location of a communication device corresponding to the communication device identifier (i.e., communication device 110) contained in the subscribing customer profile, and passes the communication device identifier to the system controller. In the preferred embodiment of the present invention, the geographical location of the communication device 110 can be determined by reference to cell sites 101-103. To determine a location of communication device 110, cell sites 101-103 each transmit a signal to communication device 110. Each signal includes an identifier, such as an identifying sequence of symbols, that uniquely corresponds to the cell site 101-103 transmitting the respective signal. Each signal also includes a time of transmission indication relative to the common time base. For example, in a Global System for Mobile Communication (GSM) system, which is a time division multiple access (TDMA) system, a structure of sequentially numbered time slots is provided throughout the system. Since the transmitting cell sites 101-103 are time synchronized to a common time base, the integrity of the time slot structure is maintained with high accuracy. Given that all time slots are of equal duration, communication device 110 is provided with information regarding when the time slot was transmitted. In effect, the time slot number functions as a time of transmission indication relative to the common time base. Upon receiving the signals from the cell sites 101-103, communication device 110 determines the time of transmission (e.g., the time slot number) of each signal.

The communication device 110 also determines time of arrival indications for each of the signals received from the cell sites 101-103. Since each of the signals includes a known sequence of symbols that uniquely corresponds to the cell site 101-103 transmitting the respective signal (i.e., a cell site identifier), communication device 110 performs a running correlation between a received sequence of symbols and the known sequences of symbols. When a high correlation is found, indicating that a known sequence has been received, the time is noted relative to which slot number provided the relevant symbols. Since the time slot structure is maintained with high accuracy relative to the common time base, a time of arrival can be determined. In order to determine exactly when the relevant symbols were received, compensations can be made to account for the amount of known processing delay in communication device 110 (e.g., the amount of time necessary to demodulate the symbols and compute the correlations).

Communication device 110 routes time of transmission and time of arrival information for cell sites 101-103 to controller 104 via serving cell site 101. Controller 104 also queries location database 106 for location information with respect to cell sites 101-103.

Upon receiving the time of transmission and time of arrival information, controller 104 preferably uses a weighted least-squares approach to derive a location of communication device 110. Time differences of arrival of the signals received by communication device 110 from cell sites 101-103 are calculated and a location of communication device 110 is determined using time of arrival variances, time differences of arrival variances, and a weighted least-squares solution per the technique disclosed in detail in U.S. Patent No. 5,884,215, entitled METHOD AND APPARATUS FOR COVARIANCE MATRIX ESTIMATION IN A WEIGHTED LEAST-SQUARES LOCATION SOLUTION, which patent is assigned to the assignee of the present invention and is hereby incorporated by reference herein in its entirety. In an alternative embodiment of the present invention, controller 104 may use triangulation or other geographical intersection technique to determine the location of communication device 110 based on time differences of arrival. In another alternate embodiment of the communication system 150, the location of communication device 110 might be determined by reference to only two cell sites. In this embodiment, two cell sites (e.g., cell sites 101 and 102) transmit signals to the communication device 110. Each of the signals includes an identifier, such as an identifying sequence of symbols, that uniquely corresponds to the cell site transmitting it, and each signal includes a time of transmission indication relative to the common time base. Communication device 110 determines time of transmission and time of arrival information for the two cell sites 101, 102 as described above and routes the time of transmission and time of arrival information to controller 104. Controller 104 also queries location database 106 to determine the locations of cell sites 101 and 102. Controller 104 then uses a weighted least-squares approach to derive the location of communication device 110, wliich weighted least squares approach is described in detail in U.S. Patent No. 5,929,806, entitled METHOD FOR ESTIMATING A LOCATION OF A MOBILE UNIT BASED ON AT LEAST TWO FIXED TRANSCEIVERS, which patent is assigned to the assignee of the present invention and is hereby incorporated by reference herein in its entirety.

In yet another alternative embodiment of the present invention, the three cell site or two cell site-based location determination may be made by the processor 204 in any one of cell sites 101-103 instead of by controller 104, which location determination is then conveyed by the cell site to controller 104.

In still another alternate embodiment of the present invention, the location of communication device 110 might be determined without reference to any cell site. In this alternate embodiment, communication device 110 further includes a GPS receiver. Communication device 110 employs the GPS receiver to receive signals from at least three of a constellation of GPS satellites and then determines its own location in accordance with known techniques of triangulation as applied to GPS systems. Communication device 110 then conveys its self-determined location, or signals such as pseudoranges that define its location, to system controller 104.

Upon determining the geographical location of communication device 110, or upon receiving a determined geographical location of the communication device, system controller 104 conveys the determined geographical location to a map service 109. In the preferred embodiment, the geographical location of communication device 110 determined by system 150 as described above is expressed in terms of longitude and latitude. The determined longitude and latitude is conveyed by controller 104 to map service 109. Map service 109 includes a processor coupled to a database that includes street names and a corresponding longitude and/or latitude associated with each street. Map service 109 receives the determined longitude and latitude and determines the approximate street intersection corresponding to the determined longitude and latitude. Map service 109 returns the determined street intersection to controller 104, and controller 104 conveys the determined street intersection to service platform 108. Although one method is described herein for translating longitude and latitude to street names, it is anticipated that other methods of translating longitude and latitude to a street address will be developed in the future, which methods may be used in the invention without departing from the spirit and scope of the present invention. Upon receiving the geographical location of communication device 110

(i.e., the street intersection), processor 402 of service platform 108 translates the geographical location to a digital format that may be read by voice generator 410 and appends a digital message to the translated geographical location. For example, if the street intersection is determined to be "Meacham Road and Algonquin Road, Schaumburg, Illinois" processor 402 may create the message "the serviceman is at Meacham Road and Algonquin Road in Schaumburg." Processor 402 then conveys the appended message to voice generator 410. Voice generator 410 converts the message to an audio signal and transmits the audio signal to the calling party. By providing the calling party with the determined location of the subscribing customer's communication device 110, the invention allows the calling party to determine a location of the subscribing customer and to take action accordingly. For example, suppose the subscribing customer is a subcontractor such as a plumber with whom the calling party has scheduled an appointment at the calling party's home. Furthermore, suppose the appointment is slightly ambiguous in its time frame, such as a morning or an afternoon instead of a specific hour and minute. The present invention allows the calling party to optimize a use of the time spent waiting for the arrival of the subscribing customer. For example, upon determining the sub-contractor's location, the calling party can determine whether there is sufficient time to run an errand before the sub-contractor is likely to arrive at the home.

In an alternative embodiment of the present invention, originating communication device may be a wireless communication device 130 that is digital capable and includes a display screen, a processor, and a web browsing application stored in a memory coupled to the processor. When conveying a request to determine a geographical location of a subscribing customer, the web browsing application of communication device 130 is used to convey the request in a Wireless Application Protocol (WAP) format. When processor 402 then conveys a determined location back to communication device 130 by converting the appended message to a WAP format and conveying the converted message to communication device 130. Upon receipt of the message, the web browsing application of communication device 130 displays the message on the display screen of the communication device. In yet another alternative embodiment of the present invention, the originating communication device may be DTE 140 and location tracking service platform 108 is included in a location tracking service server that is connected to the Internet 144 via PSTN 120. In the alternative embodiment, DTE 140 includes a display screen, a processor, and a memory that stores programs that are executed by the processor, including a web browsing program. A user of DTE 140 requests to use the location tracking service by activating the web browsing program and using the web browsing program to log onto the location tracking service server. In response to the user logging onto the location tracking service server, processor 402 retrieves a hypertext markup language (HTML) formatted web- page that is stored in memory 404 and conveys the web-page to DTE 140 by use of a hypertext transfer protocol (HTTP). Upon receipt of the web-page by DTE 140, the web browsing application running on the DTE processor displays the web-page on the DTE display screen. The use of DTE 140 is prompted for a LAC via a data entry field included in the web-page where the user may enter a LAC via a mouse and a keyboard coupled to DTE 140. After entering the LAC, the user selects an icon in the web-page displayed on the display screen. Selection of the icon causes the processor of DTE 140 to assemble a data packet that includes the LAC, an Internet Protocol (IP) address of the originating communication device (i.e., DTE 140), and an instruction to determine a location of a communication device based on the LAC. DTE 140 then conveys the data packet to the location tracking service server via data network 144 and PSTN 120. Upon receipt of the data packet by location tracking service server, processor 402 parses the data packet and extracts the LAC included in the data package and the instruction to determine a location of a communication device. Processor 402 determines a communication device identifier based on the LAC and with reference to memory 404, and then determines a geographical location of a communication device corresponding to the communication device identifier (i.e., communication device 110) in accordance with the process described above. Processor 402 then assembles one or more data packets that include an HTML formatted web-page for transmission to the web browsing application running on DTE 140, which HTML formatted web-page includes a message corresponding to the location of communication device 110. Processor 402 then conveys the data packets to DTE 140 based on the IP address in the data packet received from DTE 140. Upon receiving the HTML formatted web-page from the location tracking service server, the web browsing application displays the web page on the display screen of DTE 140, thereby providing the user with the location of communication device 110.

In still another alternative embodiment of the present invention, the location tracking service can provide a calling party with a short history of the location of the subscribing customer's communication device 110. In the alternative embodiment, the location tracking service intermittently updates the geographical location of communication device 110 and stores one or more of the most recently determined locations for the communication device in the subscribing customer's profile in memory 404. The stored location history may include location determinations for a predetermined, immediately preceding time period, may include a predetermined number of location determinations, may include location determinations that are retained so long as the location remains unchanged and then purged whenever the location changes with a new location stored in place of the purged locations, or may include a combination of the above.

When a calling party, such as the calling party using communication device 122, requests a location of a subscribing customer, the location tracking service determines a current geographical location of the subscriber's communication device 110 as described above. In addition, processor 402 in location tracking service platform 108 retrieves a history of the location of the communication device from memory 404. Processor 402 then assembles a message that provides the calling party with a history of locations of the communication device and conveys the message to the calling party via voice generator 410.

For example, suppose that the location tracking service updates the location of communication device 110 every 15 minutes. In addition, suppose that the determined location of communication device 110 has been "Meacham Road and Algonquin Road in Schaumburg, Illinois" for the last 9 location determinations (i.e., for 2 hours), which location determinations are all stored in the subscribing customer's profile in memory 404. When a calling party requests a location of communication device 110, location tracking service platform 108 determines a current geographical location of communication device 110 as described above. Processor 402 then retrieves a history of locations of communication device 110 from the subscribing customer's profile in memory 404. When processor 402 determines that the current location is the same as the locations stored in the customer's profile, then processor 402 assembles an message that includes the current location and the length of time that the communication device has continued to be positioned at the current location. Processor 402 then conveys an announcement based on the message to the calling party via voice generator 410, such as "the serviceman has been at Meacham Road and Algonquin Road in Schaumburg for 2 hours." Alternatively, the update intervals may be dynamic and may be varied based on the change in geographical location from one location determination to the next location determination. For example, suppose that when a location of communication device 110 changes with each location determination, the location tracking service updates a location of communication device 110 every predetermined time interval, such as every minute. When successive location determinations yield approximately identical locations, the location tracking service begins increasing the time interval between location determinations up to a maximum update interval.

Every time a geographical location is determined for communication device 110, processor 402 stores the location determination in the subscribing customer's profile in memory 404 and compares the determined location to location determinations already stored in the profile. Based on the comparison, processor 402 determines which portion of the stored locations are purged from memory 404 and which portion are retained in memory 404. For example, when the most recently determined location is different from an immediately preceding location, processor 402 may only retain in memory 404 the most recently determined location and the immediately preceding location determination, or a predetermined number of immediately preceding determinations. When the most recently determined location is approximately the same as an immediately preceding location, processor 402 may retain the most recently determined location and all stored location determinations that are approximately the same as the most recently determined location.

By storing one or more immediately preceding location determinations in the subscribing customer's profile, processor 402 is able to determine a direction of movement of the subscribing customer's communication unit 110 when the location determinations are changing. When a calling party requests a location of a subscribing customer, location tracking service platform 108 determines a current geographical location of the subscribing customer's communication device (i.e., communication device 110) as described above and processor 402 retrieves a history of locations of communication device 110 from the subscribing customer's profile in memory 404. If the currently determined location of communication device 110 is different than the locations stored in the customer's profile, then processor 402 determines a direction of movement of the communication device based on the most recent location determination and one or more of the stored location determinations. Processor 402 then assembles an announcement that includes the current location and the direction of movement, and conveys an audio announcement based on the message to the calling party via voice generator 410, such as "the serviceman is northbound on Meacham Road at the intersection with Algonquin Road in Schaumburg."

Many different possible update intervals, algorithms for a dynamic determination of update intervals, and algorithms for determining the number of location determinations that are stored in a subscribing customer's profile in memory 404 will occur to those of ordinary skill in the art. The intervals and algorithms used above are used for the purpose of illustrating the principles of the present invention and are not intended to limit the invention. It will be obvious to those of ordinary skill in the art that other intervals and algorithms may be used without departing from the spirit and scope of the present invention. By providing the calling party with the length of time that communication device 110 (i.e., the subscribing customer/service provider) has continued to be positioned at the device's current location, or with the direction of movement of the communication device, the alternative embodiments of the present invention provide additional information for the calling party to consider in determining an optimal utilization of a waiting period. For example, the calling party may determine, based on the information provided by the location tracking service, that the service provider has only just begun work on an earlier scheduled job, or appears to be occupied with a time consuming job, or is heading in a direction away from the calling party's home. The calling party may therefore decide that sufficient time exists for the calling party to complete a number of activities before the service provider arrives at the calling party's home. On the other hand, the calling party may determine, based on the information provided by the location tracking service, that the service provider is about to complete an immediately preceding scheduled job or is headed in a direction toward the calling party's home, and that the optimal use of the calling party time is to stay home and wait for the service provider.

FIG. 5 is a logic flow diagram 500 of steps executed by a location tracking service for providing a location of a communication device in a wireless communication system in accordance with a preferred embodiment of the present invention. The logic flow begins (501) when a location tracking service platform receives (502) a request for a geographical location from a user of an originating communication device, such as a calling party using a conventional or a cellular telephone. Alternatively, the an originating communication device could be a DTE and the user may be an individual communicating with the location tracking service platform via the DTE and a data network such as the Internet.

As described above, each customer subscribing to the location tracking service is provided a subscribing customer identifier by the service. The subscribing customer identifier is stored in a profile of the customer that is stored in a memory included in the location tracking service platform. Also included in the profile is a communication device identifier that corresponds to a communication device belonging to the subscribing customer. In response to receiving the request for a geographical location, the location tracking service platform prompts (503) the user for a subscribing customer identifier. In response to the prompt, the location tracking service platform receives (504) a subscribing customer identifier from the user via the originating communication device.

Upon receiving the subscribing customer identifier, the location tracking service platform, preferably a processor included in the platform and coupled to the memory, authenticates (505) the subscribing customer identifier. Preferably the processor authenticates the subscribing customer identifier by searching the memory for the existence of the identifier. Upon authenticating the subscribing customer identifier, the processor also retrieves a communication device identifier from the profile in the memory associated with the subscribing customer identifier. The processor then determines (506) a geographical location of a subscribing customer communication device, as described above, based on the communication device identifier. The processor conveys (507) the determined geographical location to the user of the originating communication device, and the logic flow ends (508). Preferably the processor conveys an announcement that includes the determined geographical location to the user via a voice generator included in the location tracking service platform and coupled to the processor. Alternatively, the processor may convey the determined location to the user by a message that is transported over the data network.

FIG. 6 is a logic flow diagram 600 of steps executed by a location tracking service for providing a location of a communication device in a wireless communication system in accordance with an alternative embodiment of the present invention. In the alternative embodiment, the location tracking service platform executes steps (601) - (606) that are similar to steps (501) - (506) of the preferred embodiment. That is, logic flow diagram 600 begins (601) when the location tracking service platform receives (602) a request for a geographical location from a user of an originating communication device. In response to receiving the request for a geographical location, the location tracking service platform prompts (603) the user for a subscribing customer identifier. In response to the prompt, the location tracking platform receives (604) a subscribing customer identifier from the user via the originating communication device.

Upon receiving the subscribing customer identifier, the location tracking service platform authenticates (605) the subscribing customer identifier. The processor then determines (606) a first geographical location of a subscribing customer communication device based on the communication device identifier. The processor stores (607) the first geographical location in the subscribing customer's profile in the memory. The processor determines (608) a second geographical location of the subscribing customer communication device, by a geographical location determining process described above, and determines (609) a direction of movement of the subscribing customer communication device based on the first geographical location and the second geographical location.

The processor conveys (610) the determined direction of movement of the subscribing customer communication device to the user of the originating communication device, and the logic flow ends (611). Preferably the processor conveys an announcement that includes the determined direction of movement to the user via a voice generator included in the location tracking service platform and coupled to the processor. Alternatively, the processor may convey the determined location to the user by a message that is transported over the data network. FIG. 7 is a logic flow diagram 700 of steps executed by a location tracking service for providing a location of a communication device in a wireless communication system in accordance with another alternative embodiment of the present invention. As shown in FIG. 7, logic flow diagram 700 includes steps (601) - (608) of logic flow diagram 600. However, instead of determining (609) a direction of movement of the subscribing customer communication device, in logic flow diagram 700 the processor determines (709), based on the determination of the first geographical location and the determination of the second geographical location, a time period during which the subscribing customer communication device has continued to be positioned at approximately the same geographical location. Then, instead of conveying (610) the determined direction of movement, the processor conveys (710) the determined time period to the user of the originating communication device, and the logic flow ends (711). In general, the present invention provides a location tracking service that allows a consumer of a service provided by a service provider in the consumer's home, such as a sub-contractor or a cable TV or telephone company installer, to optimize the use of the time spent waiting for the service provider. The service provider subscribes to the location tracking service and receives a subscribing customer identifier (LAC). The service provider then provides the LAC to the consumer. When the consumer wishes to determine a location of the service provider, the consumer contacts the location tracking service and provides the LAC to the service. In response to receiving the LAC, the service provides the consumer with a geographical location of the service provider (i.e., of a communication device belonging to the service provider). The service is also capable of providing to the consumer the length of time that service provider has been positioned at the geographical location and a direction of movement of the service provider. Base on the information provided by the service, the consumer is able to make an informed decision of how to best spend the remaining time before the service provider arrives at the consumer's home. While the present invention has been particularly shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the broad scope of the present invention.

Claims

Claims I claim:

1. An apparatus for providing a location of a communication device in a wireless communication system comprising: a processor that receives a request for a geographical location from a calling party, prompts the calling party for a subscribing customer identifier in response to receiving the request for a geographical location, receives a subscribing customer identifier in response to prompting for the identifier, determines a geographical location of the communication device, and conveys the determined geographical location to the calling party.

2. The apparatus of claim 1 , further comprising a speech processing unit that prompts the calling party to provide a subscribing customer identifier in response to an instruction received from the processor, and conveys the determined geographical location to the calling party based on a message comprising the determined geographical location that is received from the processor.

3. The apparatus of claim 1, wherein the processor authenticates the subscribing customer identifier.

4. The apparatus of claim 1, wherein the processor further determines a communication unit identifier based on the subscribing customer identifier, and wherein the processor determines a geographical location of the communication device based on the communication unit identifier.

5. The apparatus of claim 4, further comprising a memory coupled to the processor stores information in the form of a profile for the subscribing customer. The profile includes the subscribing customer's LAC and a corresponding communication device identifier, preferably a numerical sequence, that is uniquely associated with the customer's communication device (i.e., communication device 110).

6. The apparatus of claim 4, wherein the speech processing unit includes a voice generator that generates an announcement that prompts the calling party to provide a subscribing customer identifier, and that generates an announcement that conveys the determined geographical location to the calling party.

7. The apparatus of claim 6, wherein the speech processing unit includes a voice response unit that receives the subscribing customer identifier from the calling party, converts the subscribing customer identifier to a digital signal, and conveys the converted subscribing customer identifier to the processor.

8. The apparatus of claim 6, further comprising a dual tone multi-frequency receiver that receives the subscribing customer identifier from the calling party, converts the subscribing customer identifier to a digital signal, and conveys the converted subscribing customer identifier to the processor.

9. The apparatus of claim 1, wherein the determined geographical location comprises a first geographical location, and further comprising a memory coupled to the processor that stores the first geographical location, which first geographical location is conveyed to the memory by the processor, and wherein the processor further determines a second geographical location of the communication device, determines a direction of movement of the communication device based on the second geographical location and with reference to the first geographical location stored in the memory, and wherein the conveyance by the processor of the determined geographical location comprises conveying the determined direction of movement of the communication device to the calling party.

10. The apparatus of claim 1, wherein the determined geographical location comprises a first geographical location, and further comprising a memory coupled to the processor that stores the first geographical location, which first geographical location is conveyed to the memory by the processor, and wherein the processor further determines a second geographical location of the communication device, determines a time period during which the communication device has continued to be positioned at approximately the same geographical location based on the determination of the first geographical location and the determination of the second geographical location, and wherein the conveyance by the processor of the determined geographical location comprises conveying either the first geographical location or the second geographical location and the determined time period to the calling party.