Abstract:
Data characterizing the presence state of a user registered to use a communication service is sent to a server for the management of presence data in order to update presence data allocated to the user of a communication service. The data sent to the server is stored as presence data allocated to the user and is made available for predefinable other users. Authorization to change presence data is given to another selected user upon user release.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is the US National Stage of International Application No. PCT/EP2004/051876, filed Aug. 23, 2004 and claims the benefit thereof. The International Application claims the benefits of German application No. 10340386.8 DE filed Aug. 29, 2003, both of the applications are incorporated by reference herein in their entirety. 
     
    
     FIELD OF INVENTION  
       [0002]     The present invention relates to a method for updating presence information assigned to a user of a communication service, to a communication system and to a control program.  
       BACKGROUND OF INVENTION  
       [0003]     Internet-based instant messaging applications for exchanging information within selected user groups without the familiar time delays of conventional e-mail applications are growing increasingly popular. Typical instant messaging applications enable a user to prepare a message to members of a selected user group, also referred to as a “buddy list”, and to send the message for essentially immediate receipt. Messages sent by members of the selected user group in the opposite direction are received by the user analogously.  
         [0004]     WO 02/43351 discloses a communication system in which a first server is provided to make available program applications and to exchange data with a first client, and a second server is provided to receive and to manage presence information assigned to the first client. Presence information indicates whether a user is currently obtainable at a specified terminal in the communication system. The first server is also provided in order to exchange data with a second client on the basis of the presence information assigned to the first client.  
         [0005]     The presence information in the communication system described in WO 02/43351 can additionally be linked with a program application. If, for example, a user accesses a program application via a terminal, the program application assigns the presence information “active” to the user and monitors the activity of the user at the terminal. If no user activity is detected for a certain period of time, the program application triggers the sending of a check message to the terminal. If the user confirms the check message at the terminal, the presence information “active” continues to be assigned to the user. If the user fails to confirm the check message at the terminal, the presence information “inactive” or a similar appropriate value is assigned to the user. The presence information assigned to the user can also influence the delivery of messages from other users. Such a message is only delivered, for example, if the presence information “active” is actually assigned to the user at the time. If the presence information “active” is not assigned to the user at the time, the message is either deleted or forwarded to a different destination identified by the presence information.  
         [0006]     It is a fundamental principle of instant messaging systems that the potential addressee of a message be obtainable. Delays in the sending and answering of messages are usual in e-mail systems, but it is generally undesirable in instant messaging systems to send a message to an addressee who will only receive the message hours or days later. Precautionary measures to determine exact presence information assigned to users in a communication system are consequently very important.  
       SUMMARY OF INVENTION  
       [0007]     An object of the present invention is accordingly to specify an efficient method for updating presence information assigned to a user of a communication service and suitable means for implementing the method.  
         [0008]     This object is achieved according to the invention by a method, a communication system and a control program having the features disclosed in the claims. Advantageous developments of the present invention are disclosed in the dependent claims.  
         [0009]     One important aspect of the present invention is that a selected other user is granted permission to change presence information subject to authorization by a user registered to use a communication service. The presence information identifies a presence status of the user and is sent to a server for managing presence information, where it is stored and made available to definable other users. The introduction of a proxy-like permission to change presence information relating to a user yields benefits in terms of the fast and precise acquisition and provision of the presence information, which is no longer necessarily exclusively the task of the user.  
         [0010]     According to an advantageous embodiment of the present invention, the communication service is an instant messaging service. This enables real-time communication or communication in near real time.  
         [0011]     The presence information is advantageously made available so that it can be retrieved by the definable other users or sent to the definable other users by means of a multicast message. This enables efficient sending or distribution of the presence information.  
         [0012]     According to a further advantageous embodiment of the present invention, the permission to change the presence information is granted by means of a message sent by the user to the server in which the selected other user is identified. This makes it possible to implement the granting of a permission with minimal overhead. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The present invention is explained in more detail below with reference to an exemplary embodiment and to the drawing, in which:  
         [0014]      FIG. 1  shows an application environment for the present invention in which a server provides an instant messaging service and manages presence information and in which a plurality of clients use the instant messaging service.  
         [0015]      FIG. 2  presents a diagram showing the exchange of messages between the clients and the server when an instant messaging application starts and when presence information is changed. 
     
    
     DETAILED DESCRIPTION OF INVENTION  
       [0016]     The application environment shown in  FIG. 1  includes a server  101  by means of which an instant message service is provided for use at multiple clients  104  to  107 . The clients  104  to  107  are connected to the server  101  by a data network  103 , for example the internet. Real-time communication connections between clients, at each of which a user has started an instant messaging application, are set up by the instant messaging service via the server  101 . The server  101  is responsible here in particular for controlling and monitoring the communication connections between the clients  104  to  107 . This also includes, by way of example, the monitoring of the bandwidth and quality of service necessary for provision of the instant messaging service.  
         [0017]     As well as providing the instant messaging service, the server  101  has the task of managing presence information relating to users of the instant messaging service. Such presence information is advantageously acquired by the server  101  in response to a request from a user for provision of an instant messaging application when an instant messaging application is started at one of the clients  104  to  107 . A database  102  assigned to the server  101  is provided to store the presence information. The server  101  is also responsible for sending presence information for a user currently using an instant messaging service to definable other users. The definable other users may for example be members of a configured user group such as a “buddy list”.  
         [0018]     Presence information can be sent to the definable other users by means of a multicast message, for example. Alternatively, it is possible to make the presence information available for retrieval by the definable other users in such a way that only the definable other users have permission to query the presence information. The server  101  is also provided to grant a permission to a selected other user, for example a proxy, to change the presence information assigned to a user. This permission is only granted if the user to whom the presence information relates has authorized such a procedure.  
         [0019]     Installed on the server  101  to carry out the tasks described is a control program  111  that can be loaded into a working memory  112  of the server  101  and whose code sections can be executed by a processor  113  of the server  101 . Execution of the control program  111  triggers the sending of information that identifies a presence status of a user registered to use the instant messaging service to the server  101  for managing presence information. When the control program  111  is executed, moreover, the information sent to the server  101  is stored as presence information assigned to the user and is made available to definable other users. Furthermore, a permission to change the presence information is granted to a selected other user subject to user authorization. These steps are carried out when the control program  111  runs on the server  101 .  
         [0020]     The diagram presented in  FIG. 2  shows an exchange of messages between the clients  104  to  107  and the server  101  when an instant messaging application starts and when presence information is changed. When a user at a first client  104  starts an instant messaging application, a message  201  containing a request for the starting of an instant messaging application is sent to the server  101 . The server  101  verifies the user&#39;s authority to start an instant messaging application and retrieves a user profile. The user profile specifies a configured user group, for example, the members of which have assigned each other a reciprocal permission to make presence information available to other members of the user group.  
         [0021]     It is assumed in the following description that the user at the first client  104  is the first user in the user group to start an instant messaging application and is consequently the first user to be assigned the presence information “active”. Being the first user, the user at the first client  104  is initially not informed about the presence statuses of other users in the user group. This does not happen until another member of the user group starts an instant messaging application at a second client  105 .  
         [0022]     When the instant messaging application is started at the second client, here too a message  202  containing a request for the starting of an instant messaging application is initially sent to the server  101  and then verified and processed by the server  101 . If the outcome of the verification of the request by the server  101  is positive, the instant messaging application is provided at the second client  105 . The user at the first client  104  is moreover informed of the new presence status of the other member of the user group by means of a message  203 . The other member of the user group at the second client  105  is also informed analogously of the presence status of the user by means of a message  204 .  
         [0023]     If the user at the first client  104  wishes, for example, to delegate the updating of his or her presence status to a proxy at a third client  106 , the user at the first client  104  sends a message  205  containing a request for the setting of a proxy to the server  101  This message  205  identifies the proxy at the third client  106  as a user permitted to change the presence information assigned to the user at the first client  104 . The server  101  responds to this user authorization by granting the proxy at the third client  106  the requested permission. If, for example, the presence status of the user at the first client  104  then changes but the said user does not cause the presence information assigned to him or her to be updated, the proxy at the third client  106  can cause this to happen by means of a message  206  containing a request for the presence information assigned to the user of the first client  104  to be changed. If the necessary permission has been granted, the server  101  responds by changing the presence status of the user at the first client  104  and sends a message  207  about a change in the presence status of the user at the first client  104  to the additional member of the user group at the second client  105 . A typical exemplary application is the updating of presence information for a user during a lunch break by a team assistant assigned to the user.  
         [0024]     The application of the present invention is not limited to the exemplary embodiment described here.