DEFINITIONS

Communication Network: Communication network is a network for establishing communication. Communication includes, but is not limited to, transferring information and data such as voice, audio, video, graphics and the like. Examples of communication network includes, but is not limited to, internet, intranets, Wide Area Networks (WANs), Local Area Networks (LANs), transducer links such as those using Modulator-Demodulators (modems), telecommunication infrastructure which includes Public Switched Telephone Network (PSTN), Global System for Mobile Communications (GSM), and CDMA network.

Communication device: A communication device is a device used to establish communication through the communication network. Different communication networks may use different communication devices. For example, communication devices to establish communication in a telecommunication infrastructure include, but are not limited to, voice phone, cordless phone, landline phone and mobile phone.

Global Navigational Satellite System (GNSS) Satellites: GNSS satellites are the satellites that form the Global Navigational Satellite System. These satellites transmit microwave signals which are captured by receivers on the Earth. These signals are used by the GNSS receivers to calculate their latitude, longitude and altitude.

GNSS Receivers: GNSS receivers are the devices which receive signals transmitted by the GNSS satellites. GNSS receivers calculate their latitude, longitude and altitude by timing the signals sent by the GNSS satellites.

SMS message: A message sent via the short messaging service (SMS) is referred to as an SMS message.

USSD message: A message sent via Unstructured Supplementary Service Data (USSD) is referred to as an USSD message.

FIELD OF THE INVENTION

The present invention relates to a method for mobile phone based tracking of vehicles. More specifically, the invention relates to the use mobile communication system in conjunction with GNSS network to determine the location of vehicles on a particular route.

BACKGROUND

In the contemporary times with the advancements in wireless communication technology, locating a vehicle has become more accurate, fast and sophisticated. A person might wish to know the location of vehicles for a number of possible reasons. A person wishing to travel from one place to other needs to know the availability of any or all the modes of local transport consisting of buses, auto-rickshaws, taxies, metros etc. This is true especially for road transport system where traffic snarls may significantly disrupt the schedules of buses and taxies. The person may wish to track the locations of buses or taxies for effectively managing his/her schedule.

Various systems have been designed to effectively transmit the vehicle location information. Conventional systems include Global Navigation Satellite System (GNSS) network. The GNSS network comprises of GNSS satellites and GNSS receivers. GNSS receivers which are coupled to the vehicle, continually receive signals transmitted by the GNSS satellites. GNSS receivers time the signals and calculate the location data of the vehicle. The location data of a vehicle comprises the latitude, longitude and altitude of the location at which the vehicle is. The GNSS receivers send the location data of the vehicle to a server, in response to requests by the server from time to time. The GNSS based tracking of vehicles presently involves installing a GNSS receiver on the vehicle enabling the driver of the vehicle to determine her position. The GNSS receiver determines the precise location of the vehicle to which it is attached, and records the location data of the vehicle at regular intervals. The recorded location data is stored within the GNSS receiver, or may be transmitted to a centrally located data base, or internet-connected computer, using a cellular (GPRS), radio, or satellite modem embedded in the unit.

One of the many civilian applications of GNSS network is in providing navigational aid to drivers. In this case, GNSS receiver has in-built map also. GNSS receivers calculate the present location of the vehicle and with the help of in-built map in the GNSS receiver. It is able to provide navigational aid to a driver.. The driver may also use the GNSS receiver to find the right path or an alternate path to reach his destination.

However, the location data of the other vehicles is inaccessible to the users. The users cannot access the location data of other vehicles like buses and taxis to determine the current location of the buses and taxis. A user may install a personal central server which receives the location data from GNSS receivers of the vehicles, to access the location data of the vehicles. In this case, user will be able to access the data of the vehicle when required. However, this option is very expensive and hence, cannot be exercised by the general public

Hence, there is a need to make the location data of vehicles accessible to the users and make the technology of accessing the location data of vehicles less expensive and affordable.

SUMMARY

The present invention discloses a method for communicating the location information of a vehicle to a user. The location information may include without limitation location data, coordinates and name of the location. The location data comprises latitude, longitude and altitude of the location. A GNSS receiver is installed in the vehicle which continually determines location data of the vehicle from the signals received from the GNSS satellites. The location data is sent to a central server over a first communication network. The central server generates the location information of the vehicle based on the obtained location data. Further, the central server includes a database for storing location data and the corresponding location information.

The user may request the central server for obtaining the location information of the vehicle. The request is sent over a second communication network. The central server retrieves the location information from the database and sends the location information to the user over a third communication network. The third communication network may be the same as the second communication network in an embodiment of the invention.

In an embodiment of the invention, the user may send an SMS message to the central server requesting the location information of the vehicle. The central server retrieves the location information of the vehicle and sends the location information to the user as a message sent via SMS, voice SMS or USSD or GPRS or USSD or as a voice response. The user may also send a request to obtain the location information via USSD or General Packet Radio Services (GPRS) or Wireless Application Protocol (WAP).

In another embodiment of the invention, the user may interact with the central server through a web interface. The user may send the request using the web interface and receive the location information via the web interface. In another embodiment, the user may create a user profile on a web interface specifying a route ID of a bus, a location and a time interval. The route ID is a unique identifier assigned to each route. The user may be alerted via SMS or GPRS or USSD or WAP, when the bus reaches the specified location in the time interval specified by the user.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic illustrating environment in which the system of the invention functions in accordance with an embodiment of the invention;

FIG.2 is a block diagram depicting a central server in accordance with an embodiment of the invention;

FIG. 3 is a flowchart depicting the steps involved in communicating location information of a vehicle to a user in accordance with an embodiment of the invention;

FIG. 4 is a flowchart depicting the steps involved in communicating location information of a vehicle to a user, in accordance with another embodiment of the invention;

FIG.5 is a flowchart depicting the steps involved in communicating location information of a vehicle to a user, in accordance with another embodiment of the invention; and

FIG. 6 is a schematic diagram representing the information displayed on a mobile phone screen of a user who has requested for location information of a vehicle in accordance with an embodiment of the invention.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent that the invention may be practiced without these specific details. Various aspects and features of example embodiments of the invention are described in more detail hereinafter.

The present invention discloses a method for communicating the location information of a vehicle to a user.

FIG. 1 is a schematic illustrating environment 100 in which the system of the invention functions in accordance with an embodiment of the invention.

Environment 100 comprises a vehicle 102, a location tracking unit (LTU) 104, a location signaling system (LSS) 106, a central server 108, a first communication network (FCN) 110, a user 112, a second communication network (SCN) 114 and a third communication network (TCN) 116.

Vehicle 102 has LTU 104 attached. LTU 104 receives signals transmitted by LSS 106 and calculates the location data using the signals. In an embodiment of the invention, LTU 104 is a Global Navigation Satellite System (GNSS) receiver and LSS 106 comprises GNSS satellites which continually transmit signals comprising location messages. The location messages sent by the GNSS satellites may include without limitation the time at which the location message was sent. The GNSS receiver further calculates the position of vehicle 102 by precisely timing the signals transmitted by the GNSS satellites. Thus, location data comprising latitude, longitude and altitude of vehicle 102 is generated by the GNSS receiver, as is well known in the prior art.

In another embodiment of the invention, LTU 104 is a mobile device and LSS 106 is a cellular network. The mobile device has cellular phone circuitry. A cellular network comprises a plurality of cell stations which send and receive radio signals to and from other cell stations and the mobile device. At any instance the mobile device may receive signals from more than one cell station.

The signals from different cell stations may be of varying strength. The relation between the signal strength and the numerical value of the signal strength is well known in the art. Each cell station is assigned a unique identifier called the cell ID. The Cell ID and location data comprising latitude, longitude and altitude of all the cell stations of a region may be stored in a database. The cell station from which the mobile device receives the strongest signals is called base station. Other cell stations surrounding the mobile device are called surrounding stations. The location data of the mobile device in the region may be calculated using the numerical value of signal strength of signals which the mobile device is receiving from the base station and surrounding stations and the location data of the base station and surrounding stations. The mobile device collects data like signal strength and cell ID of the corresponding cell station from a plurality of cell stations. The location data of a cell station may be retrieved from the database based on the cell ID. A radial vector is calculated corresponding to the location data of a cell station assuming centre of the earth as the origin. For example, suppose the latitude of a location is 12.62738. The equivalent radial expression for latitude 12.62738 is 12 degrees, 37 minutes and 38.56 seconds. The decimal part is multiplied by 60 and the integer part of the result is the minutes part of the radial expression (0.62738 * 60 = 37.6728; therefore, the minutes part is equal to 37). The decimal part of the result is again multiplied by 60 and the result is the seconds part of the radial expression. (0.6728 * 60 = 38.56; therefore, the seconds part is equal to 38.56). Similarly, the radial expression for longitude and altitude is also obtained. Hence, radial vector corresponding to a location data is a set of radial expressions of the latitude, longitude and altitude contained in the location data.

A weighted mean of the radial vectors R1,R2,R3,R4,R5,,..'Rn) of all the cell stations from which signals of non-zero strength are received, is calculated using the numerical value of signal strength of the signals (SI, S2, S3, S4, S5....Sn) received from the cell stations as the corresponding weights.

wherein, Rm is the resultant radiant vector.

Location data corresponding to the resultant radial vector is calculated. This radial vector is converted back into the corresponding latitude, longitude and altitude. The location data of the resultant vector is the location data of the mobile device. LTU 104 continually sends the location data of vehicle 102 to central server 108 over FCN 110. In an embodiment of the invention, FCN 110 may be a GSM network and the location data of vehicle 102 is sent by LTU 104 via SMS or GPRS. LTU 104 may contain a SIM card to connect to the GSM network. However, other examples of FCN 110 may include without limitation internet, intranets, Wide Area Networks (WANs), Local Area Networks (LANs), transducer links such as those using Modulator-Demodulators (modems), telecommunication infrastructure which includes Public Switched Telephone Network (PSTN), CDMA network or any combination thereof. Central server 108 generates the location information of vehicle 102 based on the location data of vehicle 102 and stores the location information in a database 202 (as shown in figure 2). In an embodiment, central server 108 is programmed to run on Dot Net (.Net) platform of the Microsoft Corp. However, it would be apparent to a person skilled in the art that any other programming platforms like Java, C or C++ can be used to run applications on central server 108. According to an embodiment of the invention, commercially available computer servers like IBM Server or HP Server or any other Intel chip based server may be used as central server 108. Location information includes but is not limited to the corresponding location data, the name of the location and the time at which vehicle 102 was at that location. Central server 108 is discussed in detail in conjunction with FIG. 2. The step of generating the location information from the corresponding location data is discussed in detail in conjunction with FIG. 3.

User 112 wishes to know the location information of vehicle 102.

User 112 may use a communication device to request central server 108 for the location information of vehicle 102. Examples of the communication device which may be used to request central server 108 for the location information may include without limitation a mobile phone, a landline phone, a computer, a laptop, an internet-enabled PDA and the likes. The request is sent over SCN 114. Examples of SCN 114 may include without limitation GSM network, internet, intranets, Wide Area Networks (WANs), Local Area Networks (LANs), transducer links such as those using Modulator-Demodulators (modems), telecommunication infrastructure which includes Public Switched Telephone Network (PSTN), CDMA network or any combination thereof. Central server 108 sends the location information of vehicle 102 as requested by user 112 overTCN 116. Examples of TCN 116 may include without limitation GSM network, internet, intranets, Wide Area Networks (WANs), Local Area Networks (LANs), transducer links such as those using Modulator-Demodulators (modems), telecommunication infrastructure which includes Public Switched Telephone Network (PSTN), CDMA network or any combination thereof. In an embodiment of the invention, the location information of vehicle 102 is received by user 112 at the same communication device which was used to request central server 108 for the location information. In another embodiment of the invention, user 112 may request for location information using one communication device but may receive the location information at a different communication device. This can be explained in conjunction with the following example. Suppose user 112 requests for location information through her computer, then user 112 may receive the location information either on her computer or via SMS on her mobile phone based on the preference user 112 has set for receiving the location information.

It will be apparent to a person skilled in art, that in an embodiment, SCN 114 and TCN 116 may be same. In another embodiment of the invention, SCN 114 and TCN 116 may be different communication network.

FIG.2 is a block diagram depicting central server 108 in accordance with an embodiment of the invention.

Central server 108 comprises database 202, processor 204, GSM modem 206 and IVRS system 208. Database 202 stores software that may be required for the operation of central server 108. The software stored may include without limitation computer programs, procedures and documentations for maintaining and running central server 108. In an embodiment of the invention, database 202 is a Microsoft SQL database. However, it would be apparent to a person skilled in the art that database 202 could be any of the databases such as Oracle, DB2, mySQL or any other commercially available database. In an embodiment, the invention may be used to track buses and provide users with location information of buses, trains, metros and other vehicles, their estimated time of arrival and the like. For the purpose of explanation of the invention, hereinafter bus 102 will be used as an instance of vehicle 102. However, it will be apparent to a person skilled in the art that the invention may also be practiced with other vehicles. In such a case, database 202 also stores data such as, names of the places and their corresponding latitudes and longitudes, coordinates of the roads, the defined route of bus 102 and the like. Database 202 may also store bus stop details including starting and terminating station names, location sequence for all route IDs. Location sequence of a route ID is the names of bus stops in sequence for the route ID. Information of bus IDs and the LTU ID installed in each bus 102 may also be stored in database 202. Bus ID is a unique identifier assigned to each bus 102. LTU ID is a unique identifier assigned to each LTU 104. Processor 204 generates the location information from the location data of bus 102 using the stored information in database 202. The location information is stored in database 202 for every individual bus with the time stamp. With the location sequence stored for every route, central server 108 determines the route ID for each bus based on the location sequence obtained across a given time period. The time period is configurable and can be replaced with number of sequences of location. With the availability of the location sequence obtained across a given time period, a snap-shot of location with route IDs and directions of each bus running on different routes can be obtained. Further, a pre-defined number of location information is used to match the route ID. Matching the sequence of location data obtained with the sequence of locations in the route map is used to determine the direction (up or down) of bus. Moreover, processor 204 analyzes similar location sequence to find if a bus has deviated from the scheduled route or if it has taken an abrupt U-turn etc.

GSM modem 206 of central server 108 receives message as an SMS message or via GPRS containing the location data of the bus from LTU 104. Further,

GSM modem 206 receives a request from user 112 for obtaining the location information of bus 102 as SMS message or USSD message sent by user 112. Further, GSM modem 206 also sends SMS message containing the requested location information to user 112. In another embodiment of the invention, GSM modem 206 may also send voice SMS containing location information to user 112. In yet another embodiment, GSM modem may send an USSD message containing the location information to user 112. In yet another embodiment, GSM modem 206 may send the location information to user 112 via WAP. In yet another embodiment, GSM modem 206 may send the location information to user 112 via GPRS.

IVRS System 208 receives voice calls made by user 112 requesting for the location information of bus 102. IVRS interacts with user 112 to acquire the information which user 112 wishes to receive. In an embodiment, the requested information is provided to user 112 in the form of voice signals by IVRS system 208.

FIG. 3 is a flowchart depicting the steps involved in communicating location information of bus 102 to user 112 in accordance with an embodiment of the invention.

At step 302, LTU 104 receives signals from LSS 106. Using the signals, LTU 104 calculates the location data of LTU 104. As LTU 104 is attached to bus 102, the location data of bus 102 can be obtained. LTU 104 continually receives location messages from LSS 106 thereby generating the location data of bus 102 at regular intervals of time.

At step 304, LTU 104 transmits the location data of bus 102 to central server 108 over the FCN 110. In an embodiment of the invention, the location data may be sent via SMS or GPRS over FCN 110.

At step 306, GSM modem 206 receives the location data of bus 102 sent by LTU 104 as an SMS message or via GPRS. The location data is stored in database 202. Processor 204 retrieves the location data from database 202. Processor 204 also retrieves other information like names of places corresponding to the location data. Using the location data and other retrieved information, processor 204 generates the location information of bus 102. At step 308, the location information is stored in database 202.

At step 310, central server 108 receives a request from user 112 to obtain the location information of bus 102 over SCN 114. In an embodiment of the invention, a web interface may be created to enable user 112 to interact with central server 108 over SCN 114.

The web interface is an application installed in central server 108 which is stored in database 202 and run by processor 204. User 112 may send the request based on an internet protocol over SCN 114 to central server 108 from the communication device.

In another embodiment of the invention, user 112 may send an SMS message from the communication device to central server 108 over SCN 114 in a predefined format to obtain the location information. In another embodiment, user 112 may send an USSD message over SCN 114 to obtain the location information. In another embodiment of the invention, user 112 may also send a request to obtain the location information via WAP. In yet another embodiment, user 112 may send the request to obtain the location information via GPRS. The embodiment of user 112 sending the SMS message to central server 108 for obtaining location information has been explained in greater detail in conjunction with FIG. 4.

In another embodiment of the invention, user 112 may make a call to central server 108. IVRS system 208 receives the call made by user 112. User 112 may make the call using the communication device over SCN 114. User 112, after getting connected to IVRS system 208 is further guided by IVRS system 208 to place the request. In an embodiment of the invention, user 112 may be presented a list of options of language, from which she can choose the language she wants to interact in. In an embodiment, IVRS system 208 presents a list of options available with a code associated to each option. User 112 may either "speak" the code or key in the code using the Dual Tone Multi Frequency (DTMF) keys on her communication device to choose an option. For example, at the beginning of the call, IVRS system 208 may play a recorded message to user 112 presenting different options of language available. For example, a typical message may be like, "Please choose your language. Press 1 for Hindi, press 2 for English, press 3 for Kannada after the beep" or "Please, choose your language. Speak '1' for Hindi, speak '2' for English or speak '3' for Kannada." User 112 may then, send DTMF signals (by pressing the DTMF keys) or speak the desired option to interact in the language of her choice. IVRS system 208 identifies the option chosen and interacts with user 112 in the language chosen by user 112. IVRS system 208 may then ask user 112 for the details of bus 102 for which user 112 wishes to receive the location information. For example, a typical message may be like, "please choose the route ID for which you wish to receive the location information." User 112 may then speak the route ID or select the route ID by pressing the DTMF keys on the communication device corresponding to the route ID. For example, in case user 112 wishes to receive the location information of bus 102 on route ID 620, user 112 may speak '6', '2', '0* (in that order) or send DTMF signals by pressing the keys '6', '2', *0' (in that order) on the communication device. Further, IVRS system 108 may ask user 112 to select the direction of the journey i.e. "upward" or "downward" of the bus. For example, a typical message played at IVRS system 208 may be like, "Please select the direction of the bus. Speak 'upward' for upward direction and 'downward' for downward direction" or "Please select the direction of the bus. Press '1' for upward direction and '2' for downward direction." User 112 may speak or press the suitable option to get the desired information. Hence, using IVRS system 208, even a semi-literate person can interact with central server 108 and obtain the location information of bus 102 in the language of the person's choice.

At step 312, the location information of the bus is sent to user 112. The location information may be sent by GSM Modem 206 to the communication device of user 112 over TCN 116. In case, central server 108 receives the request based on an internet protocol, processor 204 sends the location information to user 112 based on an internet protocol over TCN 116 to user 112. The location information is displayed to user 112 on the web interface. In another embodiment of the invention, in case central server 108 receives the request from user 112 as an SMS message, the GSM Modem 206 sends the location information as an SMS message to user 112 over TCN 116. In another embodiment, GSM modem 206 may send the location information as voice SMS to user 112. In yet another embodiment, GSM modem 206 may send an USSD message containing location information to user 112. In another embodiment of the invention, the location information may be sent via WAP to user 112. In another embodiment of the invention, the location information may be sent to user 112 via GPRS.

In another embodiment of the invention, in case a call has been made by user 112 to central server 108 for getting location information, IVRS system 208 interacts with user 112. The voice signals generated based on the location information of bus 102 is played by IVRS system 208 to user 112.

FIG. 4 is a flowchart depicting the steps involved in communicating location information of the bus to user 112, in accordance with another embodiment of the invention.

Steps 402, 404 and 406 are similar to the steps 302, 304 and 306, explained in conjunction with FIG. 3. At step 408, the location information is parsed in a predefined format. Parsing refers to arranging a plurality of elements of the location information under their corresponding headers. The plurality of elements of the location information may include without limitation, latitude, longitude, altitude and name of the location. Other information like LTU ID, bus ID and time may also be parsed. The step of parsing can be explained with the help of an example. After the location information has been generated, the following information is stored under their respective headers:

At step 410, the location information is stored in database 202 in the predefined format.

User 112 requests central server 108 for the location information of bus 102 from the communication device to a pre defined number. In an embodiment of the invention, user 112 may send the request via SMS in a predefined format to the predefined number corresponding to GSM modem 206. In another embodiment of the invention, user 112 sends an SMS message in a pre-specified format at the predefined number corresponding to a mobile service provider. The request is received by the mobile service provider, which routes the query to GSM modem 206. For example, "WAY 171u" may be a typical short code, to know the position of all the buses on route ID '171' moving in upward direction.

In another embodiment of the invention, a user interface is developed on a mobile phone which asks user 112 to select from the available list in the mobile phone and the as "u" or "d" for up and down respectively. The user interface also has an option to ask if user 112 wants response in any local language and whether she wants voice support. After submission of the request, the mobile phone collects information from the user interface and sends an SMS message to central server 108. The user interface is available in local languages also. For example, in English language the service may be named as "Where Are You??" (WAY) for locating bus 102 on a specific route ID. Similarly, in other languages the service may be named as say 'Yelli Iddira??' (Yl) in Kannada language, 'Kothay Ache??'(KA) in Bengali etc. Further, different formats may be used for different requests, for example in English language, the following formats may be used

WAY
WAY
WAY
WAY
WAY
WAY ALERT

Similarly, other formats may be used for different languages. For example, Yl may be used for response in Kannada, KA for response in Bengali and the likes.

At step 412, GSM modem 206 receives the SMS message sent by user 112. At step 414, processor 204 parses the SMS message received by GSM Modem 206. The query sent by user 112 as an SMS is separated under the respective headers. This can be explained with the help of following example. In case, user sends a query as an SMS which reads: "WAY 171 u". The query is separated into the following parts: "WAY", "171" and "u" and stored under the headers: , wherein the service header refers to the service which is being accessed (which in this case is named "where are you?"); the route ID refers to the route and direction refers to the direction in the route i.e. upward or downward, for which the location information is being requested. Processor 204 then validates the SMS message received. In case, the SMS message received is not in the predefined format, another SMS message may be sent to user 112 informing her that the format of the SMS message received from her is incorrect. Moreover, processor 204 retrieves the location information of bus 102 requested by user 112 from database 202, if message is in correct format. According to an embodiment of the invention, if location name is specified in the request (in a pre-defined format) then processor 204 calculates the estimated arrival using a standard statistical modeling. Based on location information and direction stored and the request, an SMS message or voice SMS message including without limitation the requested location information is generated by processor 204. At step 418, the generated SMS message or voice SMS message is sent by GSM modem 206 to user 112. Thus, the method and the system effectively integrates the mobile and the GNSS technology to determine the current location of bus 102 on specified route in both up and down directions. According to an embodiment of the invention, if the message sender sends request in local language, the response is sent in the same language.

For the purpose of explanation, the example of user 112 sending request as an SMS message and receiving location information as another SMS message has been used. However, it will be apparent to a person skilled in art that user 112 may also send the request as an USSD message or via WAP or via GPRS. Moreover, GSM modem 206 may send the location information as an USSD message or via WAP or via GPRS.

Using prepared templates on the user interface for mobile phones and by replying as voice SMS, even a semi-literate person can interact with central server 108 and obtain location information of the bus.

This service may also be used in school buses and corporate buses. When the bus reaches a specified location, which may come before the bus stop of a user, an alert may be sent to users informing them that the bus has reached the specified location. This gives an idea to the user about the time at which they must reach their bus stop to avoid unnecessary wastage of time by waiting for the bus. The alert may be sent to the user via at least one of SMS, voice SMS, USSD, GPRS and WAP.

One of the other applications is in case a school bus is late by a specific amount of time in reaching a particular destination. In such a case, an alert may be sent to parents of children who have to get down at any of the succeeding bus stops, informing the parents that the school bus is late.

FIG.5 is a flowchart depicting the steps involved in communicating location information of the bus to user 112, in accordance with another embodiment of the invention.

Steps 502, 504 and 506 are similar to the steps 302, 304 and 306, explained in conjunction with FIG. 3. Steps 508 and 510 are similar to the steps 408 and 410 respectively, explained in conjunction with FIG. 4.

In an embodiment of the invention, a web interface is made at which user 112 may interact with central server 108. User 112 may access the web interface through the communication device which connects user 112 to central server 108 over SCN 114. User 112 creates a user profile on the web interface. At step 512, user 112 may send a request specifying a route ID, location, a time interval and her mobile phone number via the web interface. This information is received by processor 204 and stored in database 202. At step 514, whenever, bus 102 passes the specified location on the route ID during the time interval specified by user 112, an alert is sent to user 112 at the specified mobile phone number as an SMS message by GSM modem 206. In another embodiment, the alert may be set as voice SMS message. In yet another embodiment, the alert may be sent as an USSD message. In yet another embodiment, the alert may be sent via WAP. In yet another embodiment, the alert may be sent via GPRS.

FIG. 6 is a schematic diagram representing the information displayed on a mobile phone screen of user 112 who has requested for location information of bus 102 in accordance with an embodiment of the invention.

User 112 sends a request with route ID and direction through a mobile phone user interface 602. Screen 604 shows that message is sent. Screen 606 notifies that one message is received at user 112's mobile. Screen 608 shows the location of the buses on the route ID '156' and direction 'u'.

While example embodiments of the invention have been illustrated and described, it will be clear to a person skilled in the art that the invention is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions and equivalents will be apparent to those skilled in the art without departing from the spirit and scope of the invention as described above.

WE CLAIM:

1. A method of communicating location information of a vehicle to a user, the method comprising the steps of:

a. obtaining location data of the vehicle, at a location tracking device in the vehicle;

b. storing location information of the vehicle in a central server, wherein the step of storing comprises:

i. receiving the location data of the vehicle through the location tracking device over a first communication network;

ii. generating location information from the corresponding location data; and

iii. storing the location information in a database;

c. receiving a request from the user for obtaining the location information of the vehicle, the request being sent over a second communication network;

d. transmitting the location information of the vehicle to the user over a third communication network.

2. The method as claimed in claim 1, wherein the location tracking device obtains the location data using at least one of Global Navigation Satellite System and a cellular network.

3. The method as claimed in claim 1, wherein the location data of the vehicle is sent from the location tracking device to the central server via short message service (SMS).

4. The method as claimed in claim 1, wherein the step of storing location information further comprises the step of parsing the location information in a predefined format.

5. The method as claimed in claimed 1, wherein the request from the user is received as an SMS message from the user.

6. The method as claimed in claim 1, wherein the request from the user is received via at least one of GPRS, WAP and USSD.

7. The method as claimed in claim 5 and 6, the method further comprising the steps of:

a. parsing the request received from the user; and

b. validating format of the request received from the user.

8. The method as claimed in claim 1, wherein the request from the user is received as at least one of voice signals and DTMF signals.

9. The method as claimed in claim 1, wherein the request from the user is received over at least one the internet and Voice over internet protocol or wireless access protocol.

10. The method as claimed in claim 1, wherein the location information is sent to the user via at least one of SMS, voice SMS message, USSD, GPRS, WAP and voice signals.

11. The method as claimed in claim 10, wherein the location information is sent to user in a language of choice of the user.

12. A method of communicating location information of a vehicle to a user, the method comprising the steps of:

a. receiving location data of a vehicle through a location tracking device over a communication network;

b. generating location information of the vehicle using the corresponding location data at the central server;

c. receiving a request from a user for obtaining the location information of the vehicle, the request being sent over a second communication network; and

d. sending the location information of the vehicle to the user over a third communication network.

13. The method as claimed in claim 12, wherein the location data of the vehicle is received via short message service (SMS).

14. The method as claimed in claim 12, wherein the step of storing location information further comprises the step of parsing the location information in a predefined format.

15. The method as claimed in claimed 12, wherein the request from the user is received via SMS from the user.

16. The method as claimed in claim 12, wherein the request from the user is received via at least one of GPRS, WAP and USSD.

17. The method as claimed in claim 15 and 16, the method further comprising the steps of:

a. parsing the request received from the user; and

b. validating format of the request received from the user.

18. The method as claimed in claim 12, wherein the request from the user is received as at least one of voice signals and DTMF signals.

19. The method as claimed in claim 12, wherein the request from the user is received over at least one of the internet and Voice over Internet Protocol or wireless access protocol.

20. The method as claimed in claim 12, wherein the location information is sent to the user via at least one of SMS, voice SMS, USSD, GPRS, WAP and voice signals.

21. The method as claimed in claim 20, wherein the location information is sent to the user in a language of choice of the user.