Abstract:
The invention relates to a method for providing location information from a mobile device ( 101 ) to a group of mobile devices ( 102, 103 ), said method comprising the steps of generating a message according to an instant messaging protocol, said message comprising presence information related to said mobile device ( 101 ),  
     According to the invention, an indication related to the location of said mobile device ( 101 ) is included in said message.

Description:
[0001]    This invention is based on a priority application EP 02 360 232.9 which is hereby incorporated by reference.  
         FIELD OF THE INVENTION  
         [0002]    The present invention relates to network applications in a wireless communication network and more precisely to a method for informing terminals under the range of a wireless communication network on the position of other terminals in their environment.  
         BACKGROUND OF THE INVENTION  
         [0003]    Known in the art are instant messaging systems which are used in the Internet world for signalizing the presence of users defined as belonging to a community of users to other users belonging to this community. A presence flag is displayed on the user terminal to indicate if the users of the community are ready to receive instant messages. An instant messaging protocol carrying presence information and called Common Presence and Instant Messaging Protocol (CPIM) has for example been standardized at the Internet Engineering Task Force (IETF).  
           [0004]    Instant messaging systems are already existing in the mobile phone industry for example in form of mobile originating and mobile terminating short messaging.  
           [0005]    The Wireless Village initiative also deals with such topics and has proposed to introduce instant messaging and presence services in the mobile internet society.  
           [0006]    The current trend is to include more and more pure internet applications in telecommunication networks and especially in wireless communication networks what gets possible thank to the always-on capabilities of GPRS and UMTS radio communication networks.  
           [0007]    Using instant messaging with presence services enables it to keep track of the online status and availability of the communication partners.  
           [0008]    This solution presents however the drawback that the presence (ready or busy status of a user) is usually not a sufficient information for mobile users. Indeed, usually mobile users use their mobile to help defining meeting points where the mobile users have to meet physically. For this purpose they call each other using a voice channel to check if one of the expected attendee is on the right way or to guide him orally to the meeting point. This presents the drawback to busy a voice channel for this service.  
           [0009]    A particular object of the present invention is to provide a method for mitigating the previously listed drawbacks.  
         SUMMARY OF THE INVENTION  
         [0010]    This object is achieved by a method for providing location information from a mobile device to a group of mobile devices said method comprising the steps of generating a message according to an instant messaging protocol, said message comprising presence information related to said mobile device, said message further comprising an indication related to the location of said mobile device.  
           [0011]    This object is further achieved by a mobile device able to communicate with a group of mobile devices by supporting an instant messaging client application comprising means for generating a message comprising presence information of said mobile device, said instant messaging client application comprising means for encapsulating in said message an indication related to the location of said mobile device.  
           [0012]    This object is further achieved by an instant messaging server for providing a group of mobile devices with information on at least one mobile device belonging to said group, said server comprising an instant messaging application able to send a message comprising presence information related to said at least one mobile device to said group of mobile devices, said instant messaging server further comprising:  
           [0013]    means for receiving location information related to said mobile device;  
           [0014]    means for including location information related to said mobile device in predefined field of said message destined to said group.  
           [0015]    According to the present invention, an instant messaging protocol already furnishing presence information of a mobile device is adapted to further provide location information of this mobile device to the other mobile devices of his community  
           [0016]    The method according to the present invention presents the advantage that the combination of location information with presence information provides an easy filtering of location information according to security and privacy policies as those already defined for presence information.  
           [0017]    Another advantage of the present invention is that there is no need for an instant messaging server to collect continuously the location of the different users.  
           [0018]    Further advantageous features of the invention are defined in the dependent claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    Other characteristics and advantages of the invention will appear on reading the following description of a preferred embodiment given by way of non-limiting illustrations, and from the accompanying drawings, in which:  
         [0020]    [0020]FIG. 1 shows a system comprising mobile devices belonging to a community of mobile devices where the method according to the present invention is implemented;  
         [0021]    [0021]FIG. 2 shows the data format used in the instant messaging protocol according to the present invention;  
         [0022]    [0022]FIG. 3 shows the internal structure of a mobile device according to the present invention;  
         [0023]    [0023]FIG. 4 shows the internal structure of an instant messaging server according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]    [0024]FIG. 1 shows a system comprising mobile devices  101 , . . . ,  103  belonging to a community of users where the method according to the present invention is implemented. The system further comprises a wireless communication network preferably supporting packet oriented traffic for example as GPRS (General Packet Radio Service) or UMTS (Universal Mobile Telecommunications System) networks. The wireless communication network comprises base stations  111  in the access part of the network and a core network  112 . An instant messaging server  12  according to the present invention and preferably a location server  13  connectable to the wireless communication network are also part of the system.  
         [0025]    The instant messaging server  12  as well as the location server  13  are preferably connectable to the IP backbone of the wireless communication network using the IP communication protocol to communicate together or with mobile devices  101 , . . . ,  103 .  
         [0026]    Instant messaging with presence information applications are supported by the system in that each mobile device  101 , . . . ,  103  may belong to a community of mobile devices which will be alerted on the status the other mobile devices of the community and will be able to send instant messages to other mobile devices belonging to the community.  
         [0027]    The instant messaging application is realized in that each mobile device  101 , . . . ,  103  comprise a client application which can use the IP transport service of the wireless communication network to contact instant messaging server  12 .  
         [0028]    When a mobile device wants to inform the other mobile devices of his community on his presence, the client part of the instant messaging application builds an appropriate message and addresses it to the instant messaging server  12  using the IP transport service of the wireless communication network. The IP address of the instant messaging server is known at the client application. The message has preferably the format defined in the IETF RFC 2778 “A model for presence and instant messaging”.  
         [0029]    Upon reception of this message at instant messaging server  12 , the latter checks the identity of all mobile devices belonging to the community the sender  101  of the received message belongs to, generates and sends messages to these mobile devices  102 ,  103  informing them that mobile device  101  is now available for receiving instant messaging and giving his current location.  
         [0030]    According to one embodiment of the present invention, when mobile device  101  wants to inform the other mobile devices belonging to his community on his presence, the instant messaging application adds a field comprising information on the location of mobile device  101  in the message as defined above.  
         [0031]    For this purpose the mobile device  101  has to know his position. This is preferably the case if mobile device  101  is equipped with a GPS receiver. This is also the case if the mobile device receive information from the wireless communication network which enables it to determine his position.  
         [0032]    According to another embodiment of the present invention, upon reception of a message with presence information received from mobile device  101  as defined above but containing no location information in the predefined corresponding field, instant messaging server  13  will determine the location of mobile device  101  preferably by interrogating a location server  13 .  
         [0033]    Location server  13  is reached over the wireless communication network by sending a request using the IP transport service of the wireless communication network. Location server  13  performs an estimation of the position of mobile device  101  according to one of the methods well known from persons skilled in the art and which will not be further detailed in this description.  
         [0034]    Upon response from the location server  13 , instant messaging server generates a message comprising additionally to the presence information location information of user  101  and sends it to the other mobile devices  102 ,  103  belonging to the community of mobile device  101 .  
         [0035]    The client instant messaging applications on the other mobile devices  102 ,  103  display the information on the presence status of mobile device  101  together with his location. As a consequence, the other mobile devices  102 ,  103  are informed on the location of mobile device  101  without disturbing mobile device  101  and without busying a voice channel to call and ask him about his location.  
         [0036]    [0036]FIG. 2 shows the data format used in the instant messaging protocol according to the present invention.  
         [0037]    In the embodiment of the invention where mobile device  101  indicates his location, this data format is used between mobile device  101  and instant messaging server  12  as well as between instant messaging server  12  and the mobile devices  102 ,  103  belonging to the community of mobile device  101 .  
         [0038]    In the embodiment where the location of mobile device  101  is determined at instant messaging server  13 , the format described in FIG. 2 is only relevantly used between instant messaging server and the mobile devices belonging to the community of mobile device  101 .  
         [0039]    The data format of the message comprises a field  21  corresponding to the status of mobile device  101  (e.g. busy, away, ready) indicating if mobile device  101  can be reached by the mobile devices  102 ,  103  of his community over instant messaging  
         [0040]    Moreover, the message comprises a field  22  indicating the communication address of mobile device  101 .  
         [0041]    According to the present invention, the message further comprises a field  23  indicating the location of the mobile device  101 .  
         [0042]    The location information in field  23  may be included in the message in form of a cell identifier, resp. a BSS identifier, resp an access point identifier indicating in which cell, resp. which BSS, resp. which access point of the wireless communication network the mobile device  101  is located in. This provides a low accuracy.  
         [0043]    Alternatively, the location information in field  23  may correspond to the geographical coordinates of mobile device  101 . This solution much more accurate will be preferred when mobile device  101  is equipped with a GPS receiver.  
         [0044]    Alternatively, the location information in field  23  may be a logical information, such as a postal code, a street address, a building name . . . . This alternative requires the use of geocoding functions which translate the user&#39;s geographical “x,y” position into such a logical information. Location server  13  contacts a GIS (Geographic information System) for operating this translation. It will be clear for a person skilled in the art that instant messaging server  12  itself may start the request for translation directly at the GIS without requiring the intervention of location server  13  provided an interface is available between the instant messaging sever  12  and the GIS.  
         [0045]    [0045]FIG. 3 shows the internal structure of a mobile device  101  according to the present invention. Mobile device  101  comprises an instant messaging client application compatible with a server application stored on instant messaging server  13 . The instant messaging client application comprises a software module  31  for generating a message according to an instant messaging protocol with presence information preferably according to the IETF RFC 2778 and additionally including an information on the location of mobile device  101  in the message.  
         [0046]    Preferably, mobile device  101  comprises a GPS receiver  32  connected to software module  31 . GPS receiver  32  provides location information of mobile device  101  to software module  31  for generating a message.  
         [0047]    In another embodiment of the invention, no GPS module is required if mobile device  101  receives a location indication from the wireless communication network in the form of a cell, BSS or access point identifier.  
         [0048]    [0048]FIG. 4 shows the internal structure of an instant messaging server  12  according to the present invention.  
         [0049]    Instant messaging server  12  comprises an interface  41  to a wireless communication network, a module  42  for receiving instant messages according to the present invention, a user community controller  43 , a module for transmitting messages according to the present invention  44  and optionally a location module  45 .  
         [0050]    Instant messages are received over interface  41  and submitted to module  42  for receiving instant messages. Module  42  checks the format of the received instant message.  
         [0051]    If a location field  23  indicating the location of the sending mobile device is not filled in with dummy information, this information is extracted from the message and stored at community controller  43 .  
         [0052]    Preferably, community controller  43  checks if the location has changed compared to the already stored location and if it is the case triggers module  44  for transmitting instant messages to all mobile devices registered in community controller  43  as belonging to the community of the sending mobile device. Module  44  generates then a message comprising the location information submitted by the sending mobile device preferably together with a presence information and sends it to the appropriate recipients.  
         [0053]    If no location information is available in the instant message received from the sending mobile device, module  42  for receiving instant messages triggers location module  45 . Location module  45  sends a location request to a preferably external location server itself possibly connected to a Geographical Information system. The location request comprises an identifier univocally identifying the sending mobile device. The location procedure will not be further detailed here since it is not part of the present invention.  
         [0054]    Upon answer from the location server, location module  45  stores the received location in the community control module  43  in relation with the identifier of the sending mobile device. Community controller checks if the location has changed compared to the already stored location and if it is the case triggers module  44  for transmitting instant messages to all mobile devices registered in community controller  43  as belonging to the community of the sending mobile device. Module  44  generates then a message comprising the location information submitted by the sending mobile device preferably together with a presence information and sends it to the appropriate recipients.