Abstract:
A method and device for receiving a broadcast/multicast service as discussed. According to an embodiment, the invention provides a method of receiving a broadcast/multicast service by a terminal, the method comprising: receiving a service guide from a network including a broadcast/multicast server, the service guide being used by a user to select specific contents related to a broadcast/multicast service; transmitting information on the contents selected by the user, to the network; transmitting a content request to the network; and receiving contents from the network in response to the content request, wherein the received contents were further selected, among the contents selected by the user, by the broadcast/multicast server that performed an exact location tracking of the terminal to enable location based filtering of services corresponding to the contents selected by the user.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Pursuant to 35 U.S.C. §119(a), §119(e) or §120, this application is a Continuation of U.S. patent application Ser. No. 11/155,531 filed Jun. 16, 2005 now U.S. Pat. No. 7,672,280, which claims the benefit of earlier filing date and right of priority to U.S. Provisional Application No. 60/579,669 filed on Jun. 16, 2004, Korean Application No. 10-2004-70512, filed on Sep. 3, 2004, and Korean Application No. 10-2004-90064, filed on Nov. 5, 2004. The contents of each of these applications are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a broadcast/multicast service and, more particularly, to a broadcast/multicast service based on user location information. 
     2. Description of the Related Art 
     A broadcast/multicast service, which provides sky wave broadcast or various supplementary information to mobile terminals, is a new type of service including both a broadcast service that usable information is provided by a service provider to all the clients who have subscribed for its service and a multicast service that information is provided only to a certain group of clients who have previously subscribed for a specific subject or contents. 
     Since the broadcast/multicast service can simultaneously provide the same information to multiple clients, network resources can be effectively managed, and in line with this, symbols for providing a high bandwidth application through the effective management of the network resources is increasing. In addition, clients&#39; demands for a high level of services can be satisfied by providing diverse high speed services. 
     Clients can select only a favored service among various offered information to receive it, and in this respect, a method for selectively receiving information based on location information of a client has not been defined. 
     In addition, a related art broadcast/multicast service does not define a method for allowing a server to classify multimedia type information or various contents based on a location service of a user and provide it. 
     Namely, the related art broadcast/multicast service has a problem that the same information is simultaneously provided to multiple clients and the clients are to receive the information unconditionally regardless of their location. 
     SUMMARY OF THE INVENTION 
     Therefore, one object of the present invention is to provide a broadcast/multicast service method based on user location information, by which, in providing a service to a user who has subscribed for the service, a server can selectively provide user&#39;s favored broadcast or contents based on location information of a user. 
     Another object of the present invention is to provide a broadcast/multicast service method based on user location information, by which a user can selectively receive contents or information according to a current location. 
     To achieve at least the above objects in whole or in parts, there is provided a broadcast/multicast service method based on user location information in a broadcast/multicast service system, including: setting contents desired to be received in a particular area by a terminal; and transmitting the corresponding contents to the terminal by a broadcast/multicast server when the terminal is located in a pre-set area. 
     To achieve at least these advantages in whole or in parts, there is further provided a broadcast/multicast service method based on user location information including: transmitting, by a broadcast/multicast server which has received certain contents from a contents provider, a contents list including service-available area information to one or more terminals; receiving a broadcast/multicast request message with respect to one or more contents selected by a user of a specific terminal among the contents list; checking, by the broadcast/multicast server, location information of the specific terminal through a location server; and transmitting contents corresponding to a current location of the specific terminal to the specific terminal. 
     To achieve at least these advantages in whole or in parts, there is further provided a broadcast/multicast service method based on user location information including: transmitting, by a broadcast/multicast server which has received certain contents from a contents provider, a contents list including service-available area information to one or more terminals; receiving a broadcast/multicast request message with respect to one or more contents selected by a user of a specific terminal from the contents list; receiving current location information of the specific terminal from the specific terminal; and transmitting contents corresponding to a current location of the specific terminal to the specific terminal. 
     To achieve at least these advantages in whole or in parts, there is further provided a method for providing a broadcast/multicast service based on user location information in which a broadcast/multicast service is provided to at least one or more terminals each having a client performing transmission/reception through the same network, including: transmitting, by a broadcast/multicast server which has received one or more contents, the contents information to the client; receiving a broadcast/multicast request message with respect to contents selected by a user of a specific terminal among the contents information from the client; transmitting by the broadcast/multicast server a location tracking request message with respect to the specific terminal to a location server; receiving a response message with respect to the location tracking request from the location server; and transmitting contents corresponding to the location information to the specific terminal. 
     To achieve at least these advantages in whole or in parts, there is further provided a method for providing a broadcast/multicast service based on user location information in which a broadcast/multicast service is provided to at least one or more terminals each having a client performing transmission/reception through the same network, including: receiving, by the client, contents information with respect to one or more contents from a broadcast/multicast server; transmitting a broadcast/multicast request message with respect to contents selected by a user of a specific terminal among the contents information to the broadcast/multicast server; transmitting by the client a location tracking request message with respect to the specific terminal to a location server; receiving a response message with respect to the location tracking request including a location tracking result from the location server; transmitting, by the client, location information of the specific terminal to the broadcast/multicast server; and receiving contents corresponding to a current location of the specific terminal, among the selected contents, from the broadcast/multicast server. 
     To achieve at least these advantages in whole or in parts, there is further provided A method for providing a broadcast/multicast service based on user location information in which a broadcast/multicast service is provided to at least one or more terminals each having first and second clients each being connected to a different network, including: transmitting, by a broadcast/multicast server which has received one or more contents, the contents information to the first client; receiving a broadcast/multicast request message with respect to contents selected by a user of a specific terminal among the contents information from the second client; transmitting, by the broadcast/multicast server, a location tracking request message with respect to the specific terminal to a location server; receiving a response message with respect to the location tracking request from the location server; and transmitting contents corresponding to the location information among the contents, which have been selected by the user, to the first client. 
     To achieve at least these advantages in whole or in parts, there is further provided A method for providing a broadcast/multicast service based on user location information in which a broadcast/multicast service is provided to at least one or more terminals each having first and second clients each being connected to a different network, comprising: receiving, by the first client, contents information with respect to one or more contents from a broadcast/multicast server; transmitting, by the second client, a broadcast/multicast request message with respect to contents selected by a user of a specific terminal among the contents information to the broadcast/multicast server; transmitting, by the second client, a location tracking request message with respect to the specific terminal to a location server; receiving, by the second client, a response message with respect to the location tracking request including a location tracking result; transmitting, by the second client, location information of the specific terminal to the broadcast/multicast server; and receiving, by the first client, contents from the broadcast/multicast server. 
     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims. 
     According to an embodiment, the invention provides a method of receiving a broadcast/multicast service by a terminal, the method comprising: receiving a service guide from a network including a broadcast/multicast server, the service guide being used by a user to select specific contents related to a broadcast/multicast service; transmitting information on the contents selected by the user, to the network; transmitting a content request to the network; and receiving contents from the network in response to the content request, wherein the received contents were further selected, among the contents selected by the user, by the broadcast/multicast server that performed an exact location tracking of the terminal to enable location based filtering of services corresponding to the contents selected by the user. 
     According to an embodiment, the present invention provides a terminal for receiving a broadcast/multicast service, the terminal comprising: a transceiver configured to receive and transmit signals through a network; and a client module configured to cooperate with the transceiver and to: receive a service guide from the network including a broadcast/multicast server, the service guide being used by a user to select specific contents related to a broadcast/multicast service; transmit information on the contents selected by the user, to the network; transmit a content request to the network; and receive contents from the network in response to the content request, wherein the received contents were further selected, among the contents selected by the user, by the broadcast/multicast server that performed an exact location tracking of the terminal to enable location based filtering of services corresponding to the contents selected by the user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: 
         FIG. 1  is a block diagram showing the construction of a broadcast/multicast system in accordance with an embodiment of the present invention; 
         FIG. 2  is a signal flow chart of a broadcast/multicast service method in accordance with a first embodiment of the present invention; 
         FIG. 3  is a signal flow chart of a broadcast/multicast service method in accordance with a second embodiment of the present invention; 
         FIG. 4  illustrates examples of items included in a service guide entry in accordance with the present invention; 
         FIGS. 5A to 5C  and  6 A to  6 G illustrate examples of a location tracking request message and a corresponding response message expressed in an XML (extensible Markup Language); 
         FIG. 7  shows an example of search table of a database of a broadcast server; 
         FIG. 8  is a signal flow chart of a broadcast/multicast service method in accordance with a third embodiment of the present invention; and 
         FIG. 9  is a signal flow chart of a broadcast/multicast service method in accordance with a fourth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A broadcast/multicast service method based on user location information in accordance with the present invention will now be described with reference to the accompanying drawings. 
     The present invention proposes interface and operation between a terminal providing user&#39;s favored contents or information and one or more servers based on user location information. In particular, the present invention proposes a broadcast/multicast service by which a server filters various contents or information based on user location information and provides it to users in a pertinent service area. In this case, the server can provide the service to every user in the pertinent area, provide the corresponding service to a terminal which requests the service in the corresponding area, or provide the corresponding service to an area requested by the user. 
     In the present invention, when a user requests a broadcast/multicast service provided in a particular area, a broadcast/multicast server checks location information of the user and provides contents or information of the pertinent area. In this case, the broadcast/multicast server checks the user location information through a location server or checks user location information transmitted from the terminal. 
       FIG. 1  is a block diagram showing the construction of a broadcast/multicast system in accordance with the present invention. 
     As shown in  FIG. 1 , the broadcast/multicast system includes a contents provider  10 , a broadcast/multicast server  30  which checks area information from contents and information received from the contents provider  10  and provides the contents and information to a corresponding area through a broadcast/multicast service, a terminal  50  which receives the contents and information from the broadcast/multicast server  30  and transmits information inputted by a user, and a location server  20  which checks location information of the terminal  50 . In this case, the contents provider  10  can simultaneously provide one or more contents to one or more terminals by using the broadcast/multicast service. 
     The terminal  50  includes a broadcast/multicast client receiving or requesting the broadcast/multicast service, and a location client receiving or requesting location information of a corresponding terminal. In this case, the broadcast/multicast client and the location client are sort of modules installed in the terminal. 
     A network for actually transmitting the contents and information between the terminal and the broadcast/multicast server includes an MBMS (Multimedia Broadcast/Multicast Service) of a 3GPP, a BCMCS (Broadcast Multicast Service) of a 3GPP2, or a DVB (Digital Video Broadcast). The network is comprehensively called BDS (Broadcast Distribution System). 
     The MBMS and BCMCS have both uplink channel and downlink channel, so interfacing between the broadcast/multicast server and the terminal in the same network can be possible. However, in case of the DVB, it has only the downlink channel, so if the terminal wants to perform communication with the broadcast/multicast server, it must be connected with a mobile communication network such as an EV-DO (Evolution Data Only) or a GSM (Global System for Mobile Communication) in order to use the uplink channel. 
     The system constructed as described above operates as follows. 
     The broadcast/multicast server receives contents from the contents provider and stores it. When the broadcast/multicast server receives current location information of a terminal from the location server or from a terminal which requests corresponding contents, it transmits contents to be provided to the pertinent area, among the stored contents, to the terminal of a user. 
     The broadcast/multicast server receives certain contents from the contents provider, classifies and stores it in a corresponding service area, receives current location information of a terminal from the location server or from the terminal requesting corresponding contents, and transmits contents provided in the corresponding area to the terminal of the user. 
     Although the broadcast/multicast server does not receive a service request from the terminal, it can provide contents and information corresponding to a current location of the terminal, and can transmit contents provided to a specific area requested by the user to the corresponding terminal regardless of the current location information of the service-requested terminal. 
       FIGS. 2 and 3  are signal flow charts showing a broadcast/multicast service method based on user location information, in which the broadcast/multicast service can be implemented through a terminal of which a broadcast/multicast client and a location client can be connected to the same network. In this case, the network is the MBMS of the 3GPP or the BCMCS of the 3GPP2. 
       FIG. 2  is a signal flow chart of a broadcast/multicast service method in accordance with a first embodiment of the present invention, in which the broadcast/multicast server, which intends to transmit contents or information related to location information, directly receives location information of a corresponding terminal from the location server. 
     As shown in  FIG. 2 , the broadcast/multicast service system includes a contents provider  10 , a location server  20 , a broadcast/multicast server  20 , a terminal  50  and an end user  60  that checks contents and information outputted to the terminal  50  and inputs certain information. The contents and information are transferred to the terminal  50  through a BDS  40 . The terminal  50  includes a BDS receiver  51 , a broadcast/multicast and location client  53 . In this case, because the broadcast/multicast client and the location client of the terminal  50  are connected to the same network, the two clients are assumed as one entity, namely, the broadcast/location client  53 . 
     The broadcast/multicast server  30  receives one or more contents from the contents provider  10  (step S 11 ). The contents include information on area to which corresponding contents are scheduled to be transmitted, namely, information on an area to which the corresponding contents can be provided. 
     Upon receiving the contents, the broadcast/multicast server  30  generates a service guide by using a service time, place (location) and a related schedule of each contents, and transmits each service guide to terminals  50  of an every area where the broadcast/multicast service is provided. In this case, the broadcast/multicast server  30  can store the contents received from the contents provider in two ways. The first one is receiving and storing the contents, and the second one is checking area information included in the contents and storing the corresponding contents according to each service area as classified. The service guide includes an entire contents list which can be provided by the broadcast/multicast server or a contents list that a user has previously requested or discriminately selected based on preference information registered when the user subscribes for the service. 
     In the case that each program or contents of the service guide includes area information, condition information with respect to a factor for discriminating a specific area, contents based on location, and service features providing each contents must be included in a corresponding service guide entry. 
     For example, the factor for discriminating a specific area includes a name of an area, a detailed address, a postal code number, accurate location coordinates, or the like, the contents include classification information as to whether corresponding contents are an advertisement or weather information or the like, the service features include information whether corresponding contents are used for only one time or periodically used or whether it is provided when a terminal enters or moves out of a specific area. Information included in the service guide entry is to be described in detail. 
     When the terminal  50  receives the service guide through the BDS receiver  51 , it displays the service guide through the broadcast/location client  53  so that the user  60  can check the service guide (step S 13 ). 
     The user  60  checks several programs and contents from the displayed service guide and selects a service guide entry corresponding to contents desired to be received at a specific position or at its location among the contents (step S 14 ). Then, a broadcast/multicast request message is transmitted to the broadcast/multicast server  30  through the broadcast/location client  53 . In this case, the broadcast/multicast request message includes information of contents selected by the user and service features as to whether the contents is used for one time or periodically provided, or information whether the contents are provided when a terminal enters or moves out of a specific area, and an ID of the terminal. The contents information can include information on an area where the corresponding contents are provided. 
     When the broadcast/multicast server  30  receives the broadcast/multicast request message from the broadcast/location client  53 , it transmits a location tracking request message to the location server  20  (step S 16 ). 
     Upon receiving the location tracking request message, the location server  20  checks whether the location information of the corresponding terminal can be disclosed (which, for example, means that a specific terminal is set whether to allow for a third party to perform location tracking on the specific terminal itself, which is also called a ‘privacy check’) (step S 17 ), and if user&#39;s permission is required for the location tracking, the location server  20  transmits a notification message with respect to permission of location tracking to the user  60 , and the user transmits a response message to the notification message (step S 18 ). 
     Location tracking of the terminal is performed between the location server  20  and the location client  53  (step S 19 ). The location tracking can be performed by using an existing location tracking method defined in the 3GPP or 3GPP2 or by using a SUPL (Secure User Plane Location). 
     The location server  20  transmits a calculated location tracking value through a response message to the location tracking request message to the broadcast/multicast server  30  (step S 20 ), and the broadcast/multicast server  30  transmits only contents corresponding to the current location tracking value among contents which have been selected by the user through the BDS  40  to the terminal  50  (step S 21 ). In this case, the contents include the location tracking value of the corresponding terminal. 
     In the process of transmitting the contents by the broadcast/multicast server  30 , in case that the contents received from the contents provider  10  are classified and stored according to each service area, contents of the corresponding service area are transmitted to the terminal  50 , whereas if the received contents are stored as it is, contents that can be provided to the corresponding service area, among the stored contents, is transmitted to the terminal  50 . 
     The contents are transferred to the broadcast/location client  53  through the BDS receiver  51  (step S 21 ), and the broadcast/location client  53  outputs the corresponding contents for user&#39;s checking (step S 22 ). 
       FIG. 4  illustrates items included in a service guide entry in accordance with the present invention. 
     The items shown in  FIG. 4  are optionally added to indicate corresponding area information when contents list including area information is transmitted. 
     Of the items, ‘broadcast_area’ indicates including of area information for broadcasting/multicasting contents and includes ‘target_area’ or ‘hor_acc’ as sub-items. 
     ‘target area’ is an item for a part to which contents are provided and includes sub-items of ‘shape’, ‘cc’, ‘name_area’ or ‘zip_code’. ‘hor_area’ indicates a broadcast region with certain accuracy on a plane, which is, for example, used for setting a certain area on an electronic map. 
     ‘shape’ is used to indicate a geographical form, ‘cc’ is a country code expressed by 1.about.3 digits, ‘name_area’ indicates a regional name, and ‘zip_code’ is an area code give to each area, corresponding to a postal code number. 
     The broadcast/multicast server  30  can divide a contents service area by using the items. For example, when a specific content is to be provided to a specific city, the broadcast/multicast server  30  optionally includes the items ‘broadcast_area’, ‘target_area’ and ‘name_area=specific city’ on a list of the corresponding contents. 
     The optional items are not only used for indicating a service available area of the contents list in the service guide but also for limiting an area to which each contents list is transmitted or an area to which contents are transmitted. 
     The location tracking request message that the broadcast/multicast server  30  transmits to the location server  20  and the response message with respect to the location tracking request message that the location server transmits to the broadcast/multicast server  30  can be expressed in the XML (eXtensible Markup Language) by using each factor and attribute defined in an MLP (Mobile Location Protocol) specification. 
       FIGS. 5A to 5C  and  6 A to  6 G illustrate a location tracking request message and a corresponding response message expressed in an XML (extensible Markup Language). In detail,  FIGS. 5A to 5C  illustrate embodiments of messages used for tracking a location only one time, and  FIGS. 6A to 6G  illustrate embodiments of messages used for tracking a location periodically or tracking a location when a specific event occurs. 
     Specifically,  FIG. 5A  shows a general one-time location tracking request message corresponding to a location tracking request message, which includes an ID of a terminal which requests location tracking, location tracking accuracy having time delay and spatial accuracy, a type of a location tracking value, and setting of a priority level. 
       FIG. 5B  shows an ACK message with respect to the general one-time location tracking request, which can include a result value such as whether location tracking is successful. 
       FIG. 5C  shows a response message with respect to the general one-time location tracking request, which includes only a location tracking value. 
       FIG. 6A  shows a periodical location tracking request message, and  FIG. 6B  shows a location tracking message in case where a specific even occurs, namely, for example, when a terminal enters or moves out of a specific area. 
     The location tracking message includes an ID of a terminal which requests location tracking, discrimination as to whether it is periodical location tracking or location tracking with respect to occurrence of a specific event, and a period for requesting location tracking, its start time and termination time in case of the periodical location tracking, and characters of an event (e.g., whether a terminal enters, moves out of or located within a specific area) and a name or an accurate location value of a specific area in case of tracking a location with respect to occurrence of a specific event. The location tracking message includes location tracking accuracy having time delay and spatial accuracy, a type of a location tracking value, and setting of a priority level. 
       FIGS. 6C and 6D  show ACK messages with respect to the periodical location tracking request or the location tracking request in occurrence of a specific event, namely, showing embodiment of a case where a response can be made to a location tracking request and a case where a response cannot be made to a location tracking request. 
       FIG. 6E  shows a location tracking value transmitted as a response message with respect to a periodical location tracking request or a location tracking request when a specific event occurs. 
       FIG. 6F  shows a cancellation message with respect to the periodical location tracking request or the location tracking request in case where a specific event occurs, and  FIG. 6G  shows an ACK message with respect to a minimum message. 
     Namely, the broadcast/multicast server  30  transmits the one-time location tracking request message, the periodical location tracking request message or the location tracking request message in occurrence of a specific event to the location server  20  according to characteristics of contents selected by a user. 
     In order for the broadcast/multicast server  30  to transmit only the contents corresponding to the location tracking value, a process for matching information on each contents received from the contents provider  10  and information of the terminal is required. 
       FIG. 7  shows a search table of a database of the broadcast server  30 , which includes items of a service area, a list of contents provided to each service area, an ID of a terminal subscribed for a service, and a user input value. 
     For example, a terminal with an ID of A 1  is set to receive contents of an advertisement, weather, stock information but not contents of fashion. Then, when a location tracking value of the terminal corresponds to the area ‘A’, the broadcast/multicast server transmits the contents of the advertisement, weather and stock information and does not transmit the contents of fashion. In this case, by adding such an item of area information as shown in  FIG. 4  as an option to the contents transmitted to the area ‘A’, the service area can be restricted. 
       FIG. 3  is a signal flow chart of a broadcast/multicast service method in accordance with a second embodiment of the present invention, in which the broadcast/multicast server which transmits contents related to area information receives location information of a corresponding terminal from the terminal (user). 
     The broadcast/multicast server  30  receives one or more contents from the contents provider  10  (step S 31 ), generates a service guide by using a service time, a service position and a schedule of the contents, and then transmits the service guide to terminals  50  of each area where the broadcast/multicast service is provided through the BDS  40  (step S 32 ). In this case, the broadcast/multicast server  30  can check area information included in the contents, classify corresponding contents according to each service area and store it, or store the corresponding contents without classification. The service guide includes an entire contents list that can be provided by the broadcast/multicast server  30  or includes a contents list selected based on preference information that the user previously requested or registered when having subscribed for the service. 
     Upon receiving the service guide through the BDS receiver  51 , the terminal  50  displays the service guide through the broadcast/location client  53  to allow the user  60  to check the service guide (step S 33 ). 
     When the user  60  selects contents desired to be received at a specific location or at his/her current location among the contents of the displayed service guide (step S 34 ), a broadcast/multicast request message is transmitted to the broadcast/multicast server  30  through the broadcast/location client  53  (step S 35 ). In this case, the broadcast/multicast request message includes information on an area to which the contents selected by the user is provided. 
     The broadcast/location client  53  transmits also a location tracking request message to the location server  20  as well as the broadcast/multicast request message (step S 36 ). In this case, the location tracking request message is transmitted as a format of a one-time location tracking request message, a periodical location tracking request message or a location tracking request message in case where a specific event occurs. 
     Upon receiving the location tracking request message, the location server  20  calculates a location tracking value by using an existing location tracking method or an SUPL (step S 37 ), includes the location tracking value in a response message with respect to the location tracking request, and then transmits it to the broadcast/location client  53  of the corresponding terminal (step S 38 ). 
     Upon receiving the response message, the broadcast/location client  53  transfers the location tracking value to the broadcast/multicast server  30  (step S 39 ), and the broadcast/multicast server  30  transmits only contents corresponding to the location tracking value among the contents selected by the user to the terminal  50  through the BDS  40  (step S 40 ). In this case, the contents include the location tracking value of the corresponding terminal. Herein, in case that the broadcast/multicast server  30  classifies the contents which have been received from the contents provider  10  according to each area and stores it, it transmits the contents of the corresponding service area to the terminal  50 , whereas if broadcast/multicast server  30  stores the contents without classification of the service area, it transmits the contents of the corresponding service area among the stored contents to the terminal  50 . 
     The contents transferred to the broadcast/location client  53  through the BDS receiver  51  are outputted for user&#39;s checking (step S 41 ). 
       FIG. 8  is a signal flow chart of a broadcast/multicast service method in accordance with a third embodiment of the present invention, and  FIG. 9  is a signal flow chart of a broadcast/multicast service method in accordance with a fourth embodiment of the present invention, showing implementation of a broadcast/multicast service through a terminal whose broadcast/multicast client and location client cannot be connected with the same network. In this case, the broadcast/multicast service is received through the DVB while a location information request is transmitted through the 3GPP or the 3GPP2. Because the DVB has only the downlink channel without an interaction channel, the location information is transmitted through the uplink channel of a network defined in the 3GPP and the 3GPP2. 
     As shown in  FIGS. 8 and 9 , a terminal  150 , which receives a broadcast/multicast service through a DVB network  140 , includes a DVB receiver  151 , a broadcast/multicast client  153 , a mobile client  155  for transmitting a location tracking request message to a broadcast/multicast server  130  or to a location server  120 , and a user  160 . Namely, the broadcast/multicast client  153  operates as a reception dedicated client and the mobile client  155  operates as a transmission dedicated client for transmitting specific information except for transmitting current location information of a corresponding terminal to the broadcast/multicast server  130 . 
     The broadcast/multicast service method in case where the broadcast/multicast server  130  which is to transmit contents related to area information directly receives location information of a corresponding terminal  150  from the location server  120  will now be described with reference to  FIG. 8 . 
     When the broadcast/multicast server  130  receives one or more contents from the contents provider  110  (step S 51 ), it generates a service guide by using a service time, a service position and a schedule of the contents, and then transmits the service guide to terminals  150  of every area where the broadcast/multicast service is provided through the BDS  40  (step S 52 ). In this case, the broadcast/multicast server  130  can check area information included in the contents, classify corresponding contents according to each service area and store it, or store the corresponding contents without classification. The service guide includes an entire contents list that can be provided by the broadcast/multicast server  130  or includes a contents list selected based on preference information that the user has been previously requested or registered when having subscribed for the service. 
     The service guide which has been received through the BDS receiver  51  is displayed through the broadcast/multicast client  153  for user&#39;s checking (step S 53 ). 
     When the user  160  selects contents desired to be received at his/her current location or at a specific location among the contents of the displayed service guide (step S 54 ), the mobile client  155  transmits a broadcast/multicast request message to the broadcast/multicast server  130  (step S 35 ). In this case, the broadcast/multicast request message can include information on an area to which the contents selected by the user is provided. 
     Upon receiving the broadcast/multicast request message, the broadcast/multicast server  130  transmits a location tracking request message to the location server  120  (step S 56 ), and the location server  120  checks whether the location information of the corresponding terminal  150  can be disclosed (step S 57 ). If user&#39;s permission is required with respect to the location tracking, the location server  120  transmits a notification message with respect to permission of the location tracking to the user  160  and then receives a response message (step S 58 ). In this case, the location tracking request message is transmitted as a format of a one-time location tracking request message, a periodical location tracking request message or a location tracking request message in case where a specific event occurs. 
     The location server  120  calculates a location tracking value by using an existing location tracking method or an SUPL (step S 59 ), and transmits the location tracking value through a response message with respect to the location tracking request to the broadcast/multicast server  130  (step S 60 ). 
     The broadcast/multicast server  130  transmits only contents corresponding to the location tracking value among the contents selected by the user to the terminal  150  through the DVB  140  (step S 61 ), and the broadcast/multicast client  153  receives and outputs the contents (step S 62 ). 
     Herein, in case that the broadcast/multicast server  130  classifies the contents which have been received from the contents provider  110  according to each area and stores it, it transmits the contents of the corresponding service area to the terminal  150 , whereas if broadcast/multicast server  130  stores the contents without classification of the service area, it transmits the contents of the corresponding service area among the stored contents to the terminal  150 . 
     The broadcast/multicast service method in case where the broadcast/multicast server which transmits contents related to area information directly receives location information of a corresponding terminal  150  from the terminal will now be described with reference to  FIG. 9 . 
     When the broadcast/multicast server  130  receives one or more contents from the contents provider  110  (step S 71 ), it generates a service guide by using a service time, a service position and a schedule of the contents, and then transmits the service guide to terminals  150  of every area where the broadcast/multicast service is provided through the BDS  40  (step S 72 ). In this case, the broadcast/multicast server  130  can check area information included in the contents, classify corresponding contents according to each service area and store them, or store the corresponding contents without classification. The service guide includes an entire contents list that can be provided by the broadcast/multicast server  130  or includes a contents list selected based on preference information that the user has been previously requested or registered when having subscribed for the service. 
     The service guide is received by the broadcast/multicast client  153  through a DVB receiver  151  of the terminal  150 , and the broadcast/multicast client  153  displays it to allow a user  160  to check it (step S 73 ). 
     When the user  160  selects a service guide entry of contents desired to be received at his/her current location or at a specific location (step S 74 ), the mobile client  155  transmits a broadcast/multicast request message to the broadcast/multicast server  130  (step S 75 ) and a location tracking request message to the location server  120  (step S 76 ). In this case, the broadcast/multicast request message and the location tracking request message are transmitted to the broadcast/multicast server  130  and to the location server  120  through the uplink of the 3GPP or 3GPP2, not through the DVB network  140 . 
     Upon receiving the location tracking message, the location server  120  calculates a location tracking value by using an existing location tracking method or an SUPL (step S 77 ), includes the location tracking value in a response message with respect to the location tracking request, and then transmits it to the mobile client  155  of the corresponding terminal  150  (step S 78 ). 
     Upon receiving the response message, the mobile client  155  transfers the location tracking value to the broadcast/multicast server  130  (step S 79 ), and the broadcast/multicast server  130  transmits only contents corresponding to the location tracking value among the contents that can be provided to the corresponding terminal, to the terminal  150  through the DVB network  140  (step S 80 ). In this case, the contents include the location tracking value of the corresponding terminal. Herein, in case that the broadcast/multicast server  130  classifies the contents which have been received from the contents provider  110  according to each area and stores it, it transmits the contents of the corresponding service area to the terminal  150 , whereas if broadcast/multicast server  30  stores the contents without classification of the service area, it transmits the contents of the corresponding service area among the stored contents to the terminal  150 . 
     Upon receiving the contents through the DVB receiver  151 , the broadcast/multicast client  153  outputs the contents (step S 81 ). 
     In this embodiment, when the broadcast/multicast server receives a response for specific contents from the terminal, it provides the corresponding contents to the terminal. In this respect, however, although the broadcast/multicast server does not receive a request for contents from the terminal, it can check a location of the terminal through the location server to selectively provide contents according to a current location of the terminal, or can provide contents requested by the user regardless of the current location of the terminal. 
     For example, when the broadcast/multicast server  30  receives contents from the contents provider  10 , it can check the terminal positioned in a specific area through the location server  20  and transmit contents that can be provided to the corresponding area to terminals  50  within the area. 
     In addition, when the broadcast/multicast server  30  receives contents from the contents provider  10 , it can classify/store the contents according to a service area by using area information of the contents, and then, when a terminal requests contents of a specific area, the broadcast/multicast server  30  transmits contents of the corresponding area to the terminal  50 . 
     As so far described, the broadcast/multicast service method based on user location information in accordance with the present invention has many advantages. 
     That is, for example, because only pre-set information or contents is/are selectively provided based on user location information, a waste of a communication channel can be prevented. 
     In addition, since the user selectively receives contents or information according to his/her current location, user&#39;s satisfaction and convenience with respect to a service can be enhanced. 
     The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structure described herein as performing the recited function and not only structural equivalents but also equivalent structures.