Vehicle communicating method and apparatus

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NORWAY (12) INTERPRETATION WRITING (19) NO (11) 180769 (13) B (51) Int Cl⁶ H 04 B 7/26, G 08 G 1/127, H 04 Q 7/38

NIPO

17.01.91, US, 642436 (21) Application no. (22) Start day (24) Running day (41) Alm. avail.

(44) Explanation date

912516

26.06.91

26.06.91

20.01.92

03.03.97 (86) Entering date and application number (85) Continuation day (30) Priority

<td>(71) Seeking</td><td>HighwayMaster Communications Inc., 16479 Dallas Parkway, Suite 710, Dallas, TX 75248, US</td>

<td>(72) Inventor (74) Agent</td><td>Larry C. Wortham, Dallas, TX, US Tandberg Patent Office AS, 0306 OSLO</td>

(54) Designation Method and system for locating and communicating with vehicles (56) Published publications DE Al 3516357, EP A2.3 367935, EP 242099, EP 290725 (57) Abstract

There is provided a method and a device for locating and communicating with vehicles (24), wherein said device comprises at least one mobile cell unit connected to at least one microprocessor and installed in a vehicle. The microprocessor interrupts the mobile cell unit to obtain location information from an air message stream transmitted from cell phone transmitter locations. The location (26) is displayed on a screen located in the vehicle (24), or the microprocessor periodically instructs the mobile cell unit to initiate a call to a host controller (10), and upon receipt of transmission instructions from the host controller (10), it sends the location information for display on a display (12) connected to the host controller (10).

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BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a system for locating and communicating with a vehicle using a cellular telephone network, the network comprising a plurality of cellular telephone systems, the system comprising a location-locating receiver for placement on the vehicle and adapted to receive geographical location data from a location-locating system the geographical location data provides an approximate location of the vehicle, a cell transmitter receiver connected to the location locating receiver and arranged to transmit the geographical location data over the cell phone network, and a remote control unit connected to the cell phone network and adapted to receive the geographical location data transmitted by the cell transmitter network. mottåkeren.

Furthermore, the invention relates to a method of locating and communicating with a vehicle using a cellular telephone network, which network comprises a number of cellular telephone systems wherein a location-locating receiver disposed on the vehicle is adapted to receive geographical location data from a position-locating system to provide an approximate geographical location of the vehicle, and wherein a cell transmitter receiver is connected to the location locating receiver and is adapted to transmit over the cellular telephone network the geographical location data of the vehicle to a remote control unit connected to the cellular telephone network.

The invention also relates to a system and method of the type set forth in the preamble of claim 3 and claim 10, respectively.

In industries that use a large number of vehicles driving in different geographical areas, such as In the long haul truck industry, historically, drivers of vehicles must periodically communicate with a base or home office to report information such as vehicle location, number of hours driven and any problems encountered with the vehicle. In such industries where there is a need to determine the geographical location of a vehicle, tracking systems utilizing Loran-C receivers and microwave transmitters have been used for vehicle location. The use of such equipment tends to be limited only to locating and tracking the vehicles. In many cases, the only means of locating a vehicle in service consists in stopping the driver of the vehicle, exiting the vehicle and dialing a report to the home office from a public payphone. To date, the cell phone industry has not been able to penetrate the truck driving market and other industries where vehicle location is desired, for such reasons as high start-up costs for obtaining terminal equipment, and high operating costs.

EP-A-0 290 725 discloses a method for determining the approximate location of a mobile radio station by transmitting position information superimposed on voice signals transmitted by the mobile station. The mobile station receives a data telegram containing a characteristic station number, and transmits this data telegram overlaid over a voice signal to a central assessment site.

DE-A-3,516,357 discloses a location and display system arranged in a vehicle which determines location based on fixed station characteristics. The display in the vehicle is automatically adjusted based on the specific location of a mobile radio station.

EP-A-0 367 935 discloses a location and navigation system that uses location-fixed radio station numbers to approximate vehicle location, and which shows a map within the vehicle corresponding to the particular location. The known system automatically selects relevant map sections to be displayed to the driver.

EP-A-0 242 099 discloses an anti-theft and location system utilizing the global positioning system and a cellular mobile telephone system to sense a vehicle break-in and locate stolen vehicles. This publication shows an anti-theft device in which the establishment of a radio connection between the vehicle and a central station is achieved in response to an unauthorized access to the vehicle.

According to the present invention, there is provided a system of the type initially introduced which comprises a database in the remote control unit and which contains a roaming number for a particular cell phone system serving an area comprising the approximate geographical location of the vehicle, and a communication device in the remote control unit for placing calls from the remote control unit to the vehicle using the roaming number.

According to the invention, there is also provided a method of the type initially described which comprises the steps of interrogating a database in the remote control unit to obtain a number associated with a particular cellular telephone system serving an area comprising the approximate one. / geographical location of the vehicle, and placing a call from the remote control unit to the vehicle using the number.

According to the invention, there is also provided a system of the type set forth in the preamble of claim 3, which is characterized by the features defined in the characterizing portion of this claim. Further, there is provided a method of the type set forth in the preamble of claim 10 which is characterized by the features set forth in the characterizing portion of this claim.

The method and system of location and communication of the present invention overcomes the above-mentioned and other problems associated with the prior art, utilizing existing cellular telephone system services and information. A microprocessor interrogates a cell phone located in the vehicle to obtain location information received by the cell phone in an air message stream transmitted from the particular cell system providing service or service at the time of interrogation. A call is initiated from the cell phone to a remote control unit to display the vehicle's location on a map and text display of any other vehicle information transmitted from the vehicle. A voice activation / recognition device is coupled to the microprocessor, and a hands-free microphone and speaker are coupled to the speech activation / recognition device to allow hands-free operation of the system by the driver of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to embodiments with reference to the drawings, in which: FIG. 1 is a diagram illustrating communication between the vehicle and the host controller of the invention over a mobile cell system; FIG. 2 shows a block diagram of the vehicle part of the location and communication system according to the invention; FIG. 3 is a block diagram of the host controller portion of the location system of the invention; FIG. 4 shows a flow chart of the operation of the in-vehicle part of the location and communication system according to the invention; 5 shows a flow chart of the operation of the host portion of the location and communication system of the invention; and FIG. 6 is a block diagram of the hardware of a location system located in a vehicle comprising a second embodiment of the invention.

Referring now to the drawings, and more particularly to FIG. 1, there is shown an illustration of the location and communication system of the invention comprising a central data acquisition device or remote controller (hereinafter referred to as the host controller) 10 having a display 12 and a keyboard 14 connected thereto. As shown by means of a directional arrow 16, the host controller 10 communicates with a mobile telephone switching office 18 which in turn, as shown by a directional arrow 20, communicates with a special cell transmitter 22 for transmitting and receiving signals from a vehicle 24 which is equipped with a mobile cell transmitter receiver (not shown) connected to at least one microprocessor (not shown).

As shown in FIG. 1, an air message stream containing cell system identification information, including the SID number and, where transmitted, the cell identification number and transmitter location coordinates, is emitted from the cell transmitter 22 and received by the vehicle portion of the location and communication system (not shown). The signal is then read by the in-vehicle portion of the location and communication system, to determine the existence of sufficient signal strength for transmission from the vehicle 24. Upon reading a sufficient signal strength and / or expiration of a predetermined time period, a report is automatically sent from the vehicle 24 to the cell transmitter 22 from which the signal, as shown by the directional arrow 20, is transmitted to the mobile telephone switching office 18, and thence to the host control unit 10 as indicated. using the directional arrow 16.

The received information is read by the host controller and looked up in a database associated with it and contains SID (subscriber identification numbers), roamer numbers, cell identification numbers and transmitter location coordinates, to determine the location of the reporting vehicle 24. Location 26 of the vehicle 24 then appears strongly on a map 28 displayed on the screen 12 connected to the host controller 10. At this point, the host of the host control unit 10 obtains the telephone number necessary to initiate a telephone call to the vehicle 24, using the keyboard 14 to call the telephone number from the database associated with the host control unit 10.

Long-haul truck drivers must periodically report to the base station or home office such information as the total number of driving hours, any vehicle problems, timetable changes, load status, as well as any other information needed by the home office. In order to maintain ongoing information, the location and communication system of the invention provides for automatic, periodic reporting of such information to the home office. The report is initiated in the in-vehicle section of the system.

As shown in the block diagram of FIG. 2, the vehicle portion of the system comprises a microprocessor 40 having an associated read memory (ROM) 42, an associated direct memory (RAM) 44, and an expansion port 46 for feature selection (shown in dashed lines) comprising automated engine status reporting, a truck alarm system, and a Loran-C tuning input to allow location of the vehicle using LoranC in addition to cell communication.

ROM 42 contains the necessary drivers for operating the in-vehicle part of the system. RAM 44 is available for storing operation instructions that are remotely programmable from the host controller 10.

In an attempt to monitor vehicle conditions, the optional engine status reporting feature 43 provides readings by means of the microprocessor of engine states, such as temperature, engine speed and oil pressure. In the case of the theft of the vehicle, the optional truck alarm system 45 notifies the microprocessor of notifying the mobile cell transmitter receiver 58 to initiate a call to report the theft of the vehicle. To allow localization by utilizing existing tracking system information, the optional Loran-C position input 47 provides for the reception of Loran-C position transfers.

A power supply 48 is connected to the vehicle battery to provide electrical energy for operating the microprocessor 40. A switch 50 activates an audio multiplexer 52 to receive driver input via a hands-free microphone 54. The input from the hands-free microphone 54 is then transmitted via the audio multiplexer 52 to a speech recognition unit. and synthesis unit 56 for digital form conversion readable by microprocessor 40.

Information is also received by the microprocessor 40 from the host controller via the mobile cell transmitter receiver 58 located in the vehicle. Cell radio signals are received by the mobile cell transmitter receiver 58 connected to a vehicle antenna 60. The signals are then transmitted over the cellular telephone bus 62 via the audio multiplexer 52 and a smart modem 72 to the microprocessor 40. The microprocessor 40 is connected to the audio multiplexer 52 via the smart modem 72 to allow extraction of the digital information from the analog signal and to modulate the information transmitted from the microprocessor 40. An interface 74 provides the necessary protocol for communication between the microprocessor 40 and the mobile cell unit. .

In the case of audio communication between the host control unit operator and the driver, the signals from the transmitter receiver 58 are transmitted over the cell-phone bus 62 to the handset or telephone tube 64 on the mobile cell unit. If the driver of the vehicle chooses to use the hands-free microphone 54 instead of the telephone tube 64, for audio communication with the host control unit operator, the audio communication migrates from the cellphone bus 62 via the audio multiplexer 52 to an amplifier 66 for transmission to the vehicle driver via a loudspeaker 68. is controlled by a volume control 70 which controls the amplifier 66.

Operating energy is provided to the amplifier 66 and the cellphone transmitter receiver 58 from the vehicle ignition. When the driver communicates verbally over the cell phone, he can speak either via the hands-free microphone 54 or he can lift off and talk via the telephone tube 64. For storing information through speech recognition, the hands-free microphone can be used.

As shown in the block diagram of FIG. 2, the microprocessor 40 connected to the mobile cell unit is connected to a calendar and clock 49 for documenting the date and time of storage and / or transmission of information. A report interval clock 51 provides for determining when to initiate a call to the host controller based on the expiration of a predetermined time period that is remotely programmed by the host controller and stored in RAM 44.

To prevent calls made from the mobile device to unauthorized or approved numbers from the home office, microprocessor 40 has a restricted telephone use function 53 that scans a list of approved telephone numbers that are programmed by the host controller and stored in RAM 44. The number keys on the cell phone's handset is rendered inactive. Access to the approved numbers can thus only be obtained by voice command. If the number entered by voice command is not included in the list of approved numbers, the call is automatically prevented. Similarly, lookup table 55 for authorized or approved systems prevents a call from being made when the SID number contained in the message stream at the time of interrogation is not contained in the said lookup table.

The microprocessor 40's speech recognition operation 57 provides for receiving and storing information in a memory connected to the mobile cell transmitter receiver upon receiving verbal input from the vehicle driver. In addition to reading and transmitting information, microprocessor 40 has a tracking log option 59 for recording and storing vehicle information for extended reporting periods for later report compilation.

As shown in the block diagram of FIG. 3, the central data acquisition device or the host controller portion of the location system of the invention comprises a host controller 90 coupled to a smart modem 92 to allow communication between the controller 90 and any number of telephone lines reserved for vehicle reporting only. An optional auto-dial feature 94 (shown in dashed lines) is associated with the host controller 90 for initiating calls over a watt line 96. Calls are initiated to, as well as calls received from, the vehicle over the watt line 96.

At least one terminal 98 is connected to the host controller 98. In the case of larger companies, an optional system extension configuration 104 (shown in dashed lines) utilizing an existing customer management system 106 and existing dispatch terminals 108 can be utilized to reduce system installation costs. Each terminal 98 has a screen 100 for displaying a map, location information for each reporting vehicle, and text information reported by each vehicle. A keyboard 102 is connected to each terminal 98 for remote programming of approved telephone numbers for storage in the RAM memory 44 associated with the microprocessor 40, to allow the host operator to access databases containing telephone numbers for the different locations of the reporting vehicles, for to allow menu selection, and to allow remote programming of the report time interval in the microprocessors located in each of the vehicles.

By means of an error-correcting protocol, the host controller 90 prompts the microprocessor 40 - via the mobile cell transmitter receiver 58 - to send information to the host controller. The host controller 90 receives said input via the smart modem 92 from the reporting vehicle. The information is read by the host controller 90 and location information is stored in a database associated with it. The vehicle location information is then displayed on screen 100 of terminal 98. An in-service area alarm is triggered to notify the operator of the host controller 90 of the entry of a reporting vehicle in a strong signal reporting area, to allow the operator of the host controller to initiate contact with the reporting vehicle.

In case the operator of the host controller needs to initiate contact with a vehicle, requiring the location of the vehicle, between reporting periods, the operator of the host controller 90 extracts information regarding the latest reporting date¹ and the last location of the vehicle. When using the connected keyboard 102, the operator then enters the final destination of the vehicle. The host controller 90 then determines the approximate route of the vehicle, calculates the average speed of the vehicle using previously reported driving hours and distance traveled to determine the approximate distance traveled since the last reporting period, and thereby determines the approximate location of the vehicle. Cell numbers for a predetermined area surrounding the approximate location of the vehicle are looked up in the database and dialed automatically by the host controller 90 at predetermined intervals until contact with the vehicle is reached.

The method of transmission from the in-vehicle part of the locating system according to the invention is shown in the flow chart of FIG. 4, with reference to the block diagram of FIG. 2. Initially, microprocessor 40 determines whether a predetermined time period has expired (at 120), the time interval being remotely programmed by the host controller 10. If the interval has not expired, microprocessor 40 continues to cycle until such time as a determination is made that the predetermined time period has expired. At this point, the microprocessor 40 (at 122) intercepts, via the interface 74, the mobile cell transmitter receiver 58 located in the vehicle to read the signal strength received by the mobile cell transmitter receiver 58 to determine if the vehicle is in a cell system service area (at 124). If the vehicle is in a cell system service area, the microprocessor will read the SID number (at 126) from the information received by the mobile cell transmitter receiver 58 from the air message stream and will look up the SID number (at 126) from the database installed therein, to determine the correct number key method for initiating a call from the mobile cell transmitter receiver to the host controller.

The microprocessor 40 then makes a determination as to whether the microprocessor has been remotely programmed by the host controller 10 to authorize the vehicle to dial out in the particular cell system service area (at 128) providing service to the mobile cell unit. If the call is authorized or approved, the microprocessor 40 then determines (at 130) whether the signal strength received by the mobile cell transmitter receiver 58 is sufficient to authorize initiation of a call from the vehicle to the host controller

10. If the vehicle is not authorized to call out in the service area, or if the signal strength is not sufficient, the microprocessor 40 will return to the step to determine whether the vehicle is in a service area (124) and will continue through each of the steps (at 126, 128 and 130) until a provision is obtained that the vehicle is authorized to call out of the service area; and that the mobile cell transmitter receiver 58 receives an acceptable signal strength for initiating a call. At this point, the microprocessor will tell the mobile cell unit to dial out (at 132).

After the number has been dialed, the microprocessor 40 determines whether the call has been connected to the smart modem 92 (at 134) connected to the host control unit 90 at the terminal or home office. If a determination is made that the call has not resulted in the smart modem 92, the microprocessor 40 instructs the mobile cell unit to hang up (at 136). However, if the call has been processed, the microprocessor 40 receives instructions from the host controller 90 to transmit predetermined information to the host controller. In accordance with the aforementioned instructions, microprocessor 40 (at 138) transmits the special vehicle identification number, location information obtained from the air message flow upon interrogation of the mobile cell unit, and telemetry data for such information as vehicle system status, driving hours, and any other information stored in the associated with the mobile cell transmitter receiver 58.

Once the information transmission is complete, the microprocessor 40 receives a command from the host controller 90 to disconnect (at 140). Upon receipt of the disconnect command, the microprocessor instructs the mobile cell transmitter receiver 58 to disconnect or disconnect (at 142) the call to the host controller 90.

After disconnecting or interrupting the call to the host controller 90, the microprocessor 40 reloads the interval clock (at 144) to determine the expiration of the predetermined time period during which the next automatic report from the vehicle to the host controller 90 is to be initiated. Each time the predetermined time period expires, each of the steps specified in the flow chart of FIG. 4, automatically performed to initiate transmission of a microprocessor report through the mobile cell unit over the cell phone system to the host controller where the information is read, looked up, displayed and stored by the host controller for later compilation into the detailed report covering varying time periods and any number of reporting vehicles.

Referring now to FIG. 5, there is shown a flow chart of the operation of the central data acquisition device or the host controller portion of the location system. As shown in FIG. 5, with reference to the block diagram of FIG. 3, when a call is initiated by a reporting vehicle to the host controller 90, (at 200) the telephone connected to the host controller rings and answers (at 202). When paired with the host controller 90 (at 204) via the smart modem 92, the host controller 90 interrogates the microprocessor in the reporting vehicle (at 206) to determine the vehicle identification number. The host controller 90 then looks up the identification number to determine (at 208) whether the identification number one is valid. If the vehicle identification number is invalid, the host controller 90 will instruct the mobile cell phone in the vehicle to disconnect (at 210), resulting in the mobile cell unit canceling the call (at 212).

After determining that a valid vehicle identification number has been reported, the host controller 90 notifies the vehicle processor (at 214) of transmitting information regarding the location of the reporting vehicle. Upon receiving the location information (at 216), the host controller 90 instructs the microprocessor (at 218) to transmit telemetric data on different vehicles. If the host controller does not receive data (at 220) from the vehicle, it will notify (at 222) to the mobile cell unit in the vehicle to disconnect and initiate a new call. If the information is received by the host controller 90, the display 100 of the terminal 98 is updated (at 224) to display the current location information for the reporting vehicle.

Information is also stored (at 226) for later compilation into report form. Next, the host control unit 90 instructs the remote cell unit (at 210) to disconnect or interrupt the call. The call is disconnected and the cycle is restarted upon receiving a call from the mobile cell unit.

The operation of the method and device for location and communication, as described, thus combines location and communication capabilities in a system utilizing existing cell phone system services and information. The cell system that is still in use today consists of many transmitter locations in and around cities, each of which is a cell. Some of the transmitter locations are as close to each other as approx.

1.5 km or less in areas with heavy traffic. In the outermost regions of a service area, the cell transmitter sites operate at higher power levels and are more distinct from each other. A network grid across a city is formed by the adjacent cells to provide uninterrupted communication for a mobile telephone unit utilizing cell-site hands-free techniques as the vehicle moves between cells.

When in a coverage area, the mobile cell unit receives an air message stream which is sent continuously from each cell transmitter location. The mobile cell unit is automatically tuned to the strongest signal, this being the signal sent from the nearest cell transmitter location. In this way, the mobile cell unit is able to receive instructions from the cellular network as to when and where the mobile unit must be re-tuned to another voice channel in the closest nearest transmitter location before the vehicle has moved out of the range of the last transmitter location.

The location device according to the invention comprises a microprocessor which is connected to a modem which in turn is connected to an 800 MHz mobile cell radio transmitter receiver in each vehicle. At the transport base terminal or home office, a host control unit is connected via a modem to the cell transmitter to communicate with the mobile cell unit and microprocessor installed in the vehicle. As the vehicle moves from cell system to cell system and from cell to cell in each cell system, the mobile cell unit receives air message streams transmitted from cell transmitter sites located in the individual cells. Information, such as the special SID number, and the number of a particular cell from which the air message stream is being transmitted are contained in the message stream. The microprocessor connected to the mobile cell unit periodically interrogates the device to obtain the SID number and other location information transmitted in the air message stream at the time of interrogation. In the event that longitude and latitude coordinates for the physical location of the particular transmitter site transmitting the air message stream are added to the transmitted information, the microprocessor is able to interrogate the mobile cell unit to determine the longitude and latitude of the vehicle.

The strength of the radio signal carrying the message stream is also determined by the microprocessor at the time of interrogation. If the microprocessor reads a certain minimum radio signal strength and / or a predetermined period of time has expired, the microprocessor automatically instructs the cell radio receiver to initiate a telephone call to the host controller in the particular cell system providing service at that time.

At the base terminal or home office, the host controller receives the phone call and notifies the microprocessor, via a privately owned or property-protected error correction protocol, of sending information about the cell system to the host controller. The host controller requires transmission of such information as the SID number, and the cell number and transmitter coordinates received by the cell transmitter-receiver from the air message stream, and in some cases requires the driver of the vehicle to transmit information stored in a storage connected to the mobile cell unit.

Information stored by the driver of the vehicle includes information such as the identity of the vehicle, the number of hours the driver has sat at the wheel, or other information based on the needs of the user of the location and communication system. A voice start feature and a hands-free microphone connected to the mobile cell transmitter receiver allow the driver to automatically enter information about driving hours, vehicle identity and other required information without having to lift the handset.

Upon receipt of the information, the host controller looks up the SID number in a database associated with it to determine the geographical location of the SID number, thereby determining the location of the vehicle. The vehicle location is then strongly displayed on a map displayed on a screen connected to the host controller. Further information regarding driving hours, vehicle location or other required information is displayed in the text on the screen displaying the map indicating geographical location. Thus, the host control unit operator can immediately see the location of the reporting vehicle and read relevant information reported by the vehicle.

Information enabling the host control unit operator to initiate a telephone call to establish voice communication with the vehicle driver is also contained in the database associated with the host control unit. Information reported from the vehicle is stored in a host attached to the host controller for later review, analysis, or compilation into reports covering different time periods and vehicle numbers.

The database installed in the host controller also contains information regarding cell identification numbers and longitude and latitude coordinates of a particular transmitter location within the cells in case a particular cell system contains such information in the air message stream. By adding an identification number of the transmitting cell and the latitude and longitude coordinates of the cell transmitter location to the message stream, the location of the vehicle is determined more precisely. Assuming that the mobile cell unit will always align with the closest transmitter, the accuracy of the vehicle location will be approximately a radius equal to half the distance between the transmitter location at which the mobile unit is tuned and the nearest nearest location. Thus, a more accurate geographical location of the vehicle is determined.

By utilizing a voice-activated mobile cell unit, the base terminal or home office accurately monitors the location of each vehicle using conventional triangulation location techniques using cell transmitters located in adjacent cells of a cell system, and also achieves voice contact with the driver of the vehicle. at any time, using existing cell systems and system information. The location and communication system thus relieves the need for systems and equipment limited only to vehicle tracking, increases ease of driver / base availability, and avoids driver distraction while communicating with and reporting to the base terminal or home office.

As shown in the block diagram of FIG. 6, the entire location system device in a system embodying a second embodiment of the invention is contained within a vehicle to allow the driver to determine the actual location of the vehicle utilizing the information transmitted in the cell system air message flow. The vehicle location system comprises a microprocessor 250 with an associated read memory (ROM) 252 containing a driver program, an associated direct memory (RAM) 254 for storing data input by the driver, and an associated external memory port 256 for recording plug-in modules containing maps , directory directories, and other information about a particular geographic area.

A graphical display 258 to display the vehicle's geographical location and display text information is associated with the microprocessor 250 in the vehicle. An interface 260 provides communication between microprocessor 250 and graphical display 258. A smart modem 251 connects microprocessor 250 via audio multiplexer 259 to the mobile cell unit to allow communication between the microprocessor and the mobile cell unit.

As with the first embodiment of the invention, microprocessor 250, using an interface 264, performs automatic interrogation, or the driver may select a menu function using a keyboard 262 coupled to the microprocessor to initiate interrogation of the mobile cell. transmitter-receiver 266 via the cell-phone bus 268 to obtain location information from the air message stream received by the mobile cell unit via an antenna 270. Upon receipt of the location information from the air message stream, microprocessor 250 looks up the information in a database associated with microprocessor 250 to determine the geographical location of the vehicle. The geographical location is then strongly highlighted on a map displayed on the geographic display 258 connected to the microprocessor 250.

The particular map that is displayed depends on the plug-in modem currently installed in the external storage port 256 connected to the microprocessor 250. Using the keyboard 262, the driver can select specific points of interest from the various address books or directories contained in the plug-in modules. . Various menu options allow the driver to initiate calls to the particular points of interest, to clearly indicate the location of the points of interest on the map being displayed, and to receive text information regarding the calculated driving time to arrive at the selected points of interest from the available vehicle location. Using the keyboard 262, the driver can further zoom or pan the map displayed on the graphic display 258 to obtain more detailed information.

As in the first embodiment of the invention, the mobile cell unit is equipped with a telephone handset or handset 272, and has associated with a speech recognition / activation device 274 and a hands-free microphone 276 to allow operation of the location system with less driver distraction and safer vehicle operation. As with the locating system comprising the first embodiment of the invention, the in-vehicle locating system comprising the second embodiment of the invention utilizes the system identification number of the particular cell system providing service, the cell identification number where the mobile cell unit receives the air message, and the longitude and latitude range of the cell, all of which can be transmitted in the air message stream from a particular cell transmitter site.