Abstract:
In a communications system, globally unique identification of groups of users is achieved without the need for allocating a unique identifier for each group in the global number plan. Communication is initiated from a first user in the network to a first group of users in the network by transmitting a first user-specific group identifier for a first predefined group to the network; determining, in the network, the unique identifier of the first group based on the first user-specific identifier and the unique user identifier; initiating communication with at least one member of the first group. A memory means associates the unique group identifier, the user-specific group identifier and the user identity for each user with each other in such a way that the unique group identity can be determined on the basis of the user identity and the user-specific group identifier.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to a method for transmitting a message to a group of users in a communications network, a memory means for use in a communications network and a node for transmitting a message to a group of users in a communications network.  
       BACKGROUND  
       [0002]     Messaging services are a growing part of telecommunications services. In particular the use of the Short Message Service (SMS) in mobile networks is increasing.  
         [0003]     It is possible to define a group of subscribers that are to receive the same message and specify one address for the group. Any message addressed to this group will then be sent to all subscribers belonging to the group. The group address will be used as the sender. In this way, for example, a chat service in a messaging network can be implemented, for example SMS chat or MMS.  
         [0004]     Voice conferences on telephone lines and video conferences where two ore more parties communicate in a communication session involving voice and/or images are other types of group communication that have become increasingly important.  
         [0005]     Group communication requires that the sender always specifies the group name in the message or that the number used when sending the message is a unique number that is only used for this group. In the case of SMS the group must be identified by an MSISDN number.  
         [0006]     One solution for sending SMS messages to a group of subscribers is disclosed in WO94/09599. This document is primarily concerned with distributing the message and presents a solution where the message is copied to all members of the receiving group. Addressing is discussed in connection with  FIG. 5 . A unique identifier is assigned to each group. A database in the network associates the identifier of each group with the MSISDN numbers of all subscribers that are part of this group.  
         [0007]     U.S. Pat. No. 6,289,223 describes a similar solution for addressing group messages in SMS. Receiver groups are defined and a unique identifier is assigned to each group. In  FIG. 2  this group identifier is an MSISDN number.  
         [0008]     GB 2 327 571 describes an addressing method for sending SMS messages to a group of receivers. A set of group identifiers is assigned to each subscriber. To send an SMS message to a group of subscribers the address is composed of two parts: a first identifier signifying that the message is intended for a group and an identifier of the group.  
         [0009]     All of these solutions involve a unique number identifying each group. As a result the total number of groups will be limited by the number plan. To enable a sufficient number of groups the group identifiers will have to be very long. This solution is also expensive, since keeping a number globally accessible involves a cost and is normally subject to a subscription fee. For example the MSISDN numbers used for SMS are limited in numbers.  
       OBJECT OF THE INVENTION  
       [0010]     It is an object of the present invention to achieve a method and an apparatus for group messaging which enables an unlimited number of group identifiers both in messaging and communication sessions.  
       SUMMARY OF THE INVENTION  
       [0011]     This object is achieved according to the invention by a method of initiating communication in a communications network from a first user in the network to a first group of users in the network, said first user being identified by a unique user identifier and each group being associated with a unique identifier and a user-specific identifier for each user associated with the group, said method comprising the following steps: 
        initiating, by a first user, communication with a first predefined group of users by transmitting a first user-specific group identifier for the first predefined group to the network;     determining, in the network, the unique identifier of the first group based on the first user-specific identifier and the unique user identifier,     initiating communication with at least one member of the first group.        
 
         [0015]     The object is also achieved by a memory means for use in a communications network in which at least one group of users has been defined, said memory means comprising 
        a unique group identifier for the group     a user-specific group identifier for each user belonging to the group     a user identity for each user,     said unique group identifier, said user-specific group identifier and said user identity being associated in such a way that the unique group identity can be determined on the basis of the user identity and the user-specific group identifier.        
 
         [0020]     The object is also achieved according to the invention by a group management unit for achieving group communication in a communications network in which at least one group of users has been defined, said node comprising or being connectable to a memory means as defined above, said node comprising 
        receiving means for receiving a communication request for communication with a first predefined group of users, said request comprising a user-specific group identifier for the first group from a sending user,     identity means for determining the user identity of the sending user     group identification means for determining the unique group identification based on the user-specific group identifier and the user identity     transmitting means for initiating communication with at least one member of said group.        
 
         [0025]     This solution enables globally unique identification of each group without the need for allocating a unique identifier for each group in the global number plan. The method according to the invention functions globally and is not limited to one operator. The number of group identifiers can be limited to essentially the maximum number of groups to which one user belongs. Therefore, an operator, service provider or similar can provide groups at a lower cost for each group, thereby eliminating the need for a subscription fee for each group. Because of this, groups can be established easily by each user without the need for a separate subscription for each group.  
         [0026]     From a user perspective this means that the user has one address for each group, which is used to address the whole group. Each member of the group has an address for the group, but not necessarily the same address. The address is specific to each user. Since only a very limited number of group identifiers are needed the group identifiers can be kept short and simple.  
         [0027]     A group association means, such as a database, holds the associations between users and their group addresses. Each group has its internal identity that is not seen outside the group association means but only used to keep the associations. The group association means keeps the group associations, the different addresses to the members of the groups and their personal group addresses in a table of group associations.  
         [0028]     Preferably, the communication with the first predefined group of users is initiated by the first user sending a message intended for the first predefined group of users, said message being addressed to the first user-specific group identifier. Said message may comprise any type of information, for example a prompt to the recipient to connect to a conference call.  
         [0029]     Alternatively, the communication with the first predefined group of users may be initiated by the first user making a call to the first user-specific group identifier. The call to the first user-specific group identifier may be branched in the network to a conference call involving at least three users associated with the group.  
         [0030]     In the group management unit the receiving means is preferably arranged to receive a message addressed to the user-specific group identifier and the transmitting means is arranged to transmit said message to at least one member of the first group. The transmitting means may be arranged to return the message to the mobile exchange for forwarding to the at least one member of said group.  
         [0031]     Alternatively, the receiving means may be arranged to receive call set-up request to the user-specific group identifier and the transmitting means is arranged to arrange a call to at least one member of the first group.  
         [0032]     In another embodiment the receiving means is arranged to receive call set-up request to the user-specific group identifier and the transmitting means is arranged to prompt at least one member of the first group to participate in the group communication.  
         [0033]     The solution according to the invention can be used with SMS and MMS messages but also to establish telephone conferences within a group.  
         [0034]     Further, the algorithm for selecting the numbers can be enhanced so that the numbers used are better spread over the range of allocated group numbers.  
         [0035]     The method and apparatus according to the invention makes it possible to have an SMS group chat service for millions of groups by using a small number of group identities. They also enable the establishment of group conferences by using the inventive address translation feature. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0036]     The present invention will be described in more detail in the following, with reference to the appended drawings, in which:  
         [0037]      FIG. 1  shows an example involving six groups of subscribers  
         [0038]      FIG. 2  is a flow chart of how a group may be created according to the invention  
         [0039]      FIG. 3  shows a telecommunications network in which the invention may be implemented  
         [0040]      FIG. 4  is a flow chart of how to send messages to a group according to the invention  
         [0041]      FIG. 5  shows the steps carried out when a user establishes a group connection to a group defined in the network, according to a first embodiment  
         [0042]      FIG. 6  shows the steps carried out when a user establishes a group connection to a group defined in the network, according to a first embodiment 
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       [0043]      FIG. 1  shows an example of a telecommunications system involving  17  subscribers A-Q. Each subscriber belongs to one or more of six groups G1-G6. Subscribers A and B only belong to group G1. Subscriber F only belongs to group G2. Subscribers G and H only belong to group G3. Subscriber C belongs to groups G1 and G2, subscriber E belongs to groups G1 and G3 and subscriber D belongs to groups G1, G2 and G3.  
         [0044]     Subscribers I and J belong to group G4, subscribers L and M belong to group G  5  and subscriber K belongs to both G4 and G5. Subscribers N, O, P and Q only belong to group G6. G1-G6 are popular names used by the members to identify the groups. These names are optional, and may be selected to describe the group, for example, “project group X” or “members of club Y”. Each subscriber A-Q is identified by a unique address A-Q. The actual format of the address might vary depending on the type of system. In the case of SMS these addresses would be unique E.164 (telephone numbers).  
         [0045]     According to the invention, for each member of a group a number is associated with the group. This user-specific group identifier is used together with the number identifying the user (A number) to obtain a unique identifier for the group. The message can then be sent to the group identified by the unique identifier.  
         [0046]     Table 1 is an example of how the associations for all users and groups shown in  FIG. 1  might be stored in a table. The group identification is a unique identifier for the group, used only in the database. The popular name is an optional name used to help the users select the right group. In this simplified example, the popular name is G1-G6. The A number is the sender&#39;s address and the B number is the group address valid for the particular sender.  
                                   TABLE 1                                   Group                       identification   Popular name   A-number   B-number                           1   G1   A   1           1   G1   B   1           1   G1   C   1           1   G1   D   1           1   G1   E   1           2   G2   C   2           2   G2   D   2           2   G2   F   1           3   G3   D   3           3   G3   E   2           3   G3   G   1           3   G3   H   1           4   G4   I   1           4   G4   J   1           4   G4   K   1           5   G5   K   2           5   G5   L   1           5   G5   M   1           6   G6   N   1           6   G6   O   1           6   G6   P   1           6   G6   Q   1                      
 
         [0047]     The users&#39; addresses (A-numbers) would typically be telephone numbers such as E.164 addresses. The group numbers (B-numbers) would typically be selected from a small range of E.164 addresses allocated for group identification.  
         [0048]     Translating the A-numbers A-Q and the B-numbers used in table 1, into E.164 addresses, the result would be as shown in table 2. The addresses A to Q are assumed to translate as +33 6 75 07 00 01−+33 6 75 07 00 17 and the the numbers +33 1 10 00 00 01−33 1 10 00 00 03 are used as group numbers.  
                           TABLE 2                       Group   Popular               identification   name   A-number   B-number                   1   G1   +33 6 75 07 00 01   +33 1 10 00 01       1   G1   +33 6 75 07 00 02   +33 1 10 00 01       1   G1   +33 6 75 07 00 03   +33 1 10 00 01       1   G1   +33 6 75 07 00 04   +33 1 10 00 01       1   G1   +33 6 75 07 00 05   +33 1 10 00 01       2   G2   +33 6 75 07 00 03   +33 1 10 00 02       2   G2   +33 6 75 07 00 04   +33 1 10 00 02       2   G2   +33 6 75 07 00 06   +33 1 10 00 01       3   G3   +33 6 75 07 00 04   +33 1 10 00 03       3   G3   +33 6 75 07 00 05   +33 1 10 00 02       3   G3   +33 6 75 07 00 07   +33 1 10 00 01       3   G3   +33 6 75 07 00 08   +33 1 10 00 01       4   G4   +33 6 75 07 00 09   +33 1 10 00 01       4   G4   +33 6 75 07 00 10   +33 1 10 00 01       4   G4   +33 6 75 07 00 11   +33 1 10 00 01       5   G5   +33 6 75 07 00 11   +33 1 10 00 02       5   G5   +33 6 75 07 00 12   +33 1 10 00 01       5   G5   +33 6 75 07 00 13   +33 1 10 00 01       6   G6   +33 6 75 07 00 14   +33 1 10 00 01       6   G6   +33 6 75 07 00 15   +33 1 10 00 01       6   G6   +33 6 75 07 00 16   +33 1 10 00 01       6   G6   +33 6 75 07 00 17   +33 1 10 00 01                  
 
         [0049]     As can be seen, only three different numbers are needed to address six different groups. Even with millions of users, and millions of groups, the number of group addresses needed would never exceed the number of groups one person could belong to. Therefore, only a few numbers would be needed to identify the groups.  
         [0050]     In tables 1 and 2 it would be possible to other columns comprising other information. For example, an additional column could be used to indicate that a user is passively associated with a group. The user could then have a user-specific group identifier for this group, but not receive messages or invitations to participate in group communication intended for this group.  
         [0051]     According to one embodiment of the invention, a group may be established according to the following procedure, illustrated in  FIG. 2 : 
    Step S 1 : A user requests the establishment of a group, specifying the group members. This may be initiated in a number of different ways. For example, the user can send an SMS or an e-mail specifying the group members to a group server responsible for setting up the group. The group server extracts the information from the SMS or e-mail and confirms to the the user that the group has been established. Alternatively, the user may be allowed to set up the group himself, for example in a web application. The user may also be allowed to specify a popular name for the group, for example, Project1 or Family.     Step S 2 : The group server assigns a unique group identification to the group.     Step S 3 : The group server checks the members and assigns a group number for each member. Members who are not previously members of any group get the first number of the ones allocated as group numbers as a group identifier for this group. If some members are already members of other groups the operator assigns different B-numbers to different group members in dependence of the number of groups they belong to already.     Step S 4 : When the group server has assigned B-numbers for all group members, it sends information to each group member about the B-number assigned to the group for this particular group member. Each group member should also be invited at this stage to accept or reject membership. This can be implemented as an opt-in or opt-out procedure. The information can be sent to each member in such a way as to facilitate the entering of the information in his/her address book.    
 
         [0056]     The users can then start to use the group number (B-number) for calling the other members for a conference call or for sending SMS or MMS to the other members of the group. The procedure of contacting the other members is similar to making a regular call or sending an SMS to only one person and will be discussed in connection with  FIG. 4 .  
         [0057]     In step S 1 , a user may also be allowed to establish a group by calling an operator and specifying the group members orally, although this is of course more expensive than the automated solution. A method enabling the group server or operator to ascertain the user&#39;s identity is preferable. Therefore, the method of sending an SMS is preferred to the method of sending an e-mail, since it is normally not possible to determine the true originator of an e-mail.  
         [0058]      FIG. 3  illustrates a mobile telecommunications network in which the invention has been implemented. The network is simplified. In a real network other units than the ones shown will also be present. As an example, assume a first user C, identical to user C in  FIG. 1 , who wishes to send an SMS to group G2, that is, to users D and F. This user C belongs to group G1 and G2. According to the invention, as seen from table 2, the user C therefore sends an SMS to G2 by sending the SMS to the address+33 1 10 00 00 02. The SMS is received in a first base station  3  and transmitted to a mobile exchange  5 . In the mobile exchange  5  an analysis is performed to see to whom the message should be sent. If the message is identified as a group message, the mobile exchange  5  forwards the message to a group management unit  7 , which is responsible for determining to which group the message should be sent. The group management unit  7  requests information from a database  9 , which includes information as discussed in connection with table 2. The group management unit  7  determines, based on the number of subscriber C, i.e. +33 6 75 07 00 03 and the number entered in the address field, i.e. +33 1 10 00 00 02, that the message is to be transmitted to the group G2. The message is then returned to the mobile exchange  5  and transmitted, through the first base station  3  and/or other base stations  11 , present in the network, to the other members of group G2, that is, to users D and F in  FIG. 1 .  
         [0059]     To perform the functions according to the invention the group management unit  7  comprises the following units:  
         [0060]     Receiving means  13  for receiving the message that is to be sent to a group. Identity means  15  for determining the user identity of the sending user (A number). This can be done by A-number analysis, which is a well known method. Group identification means  17  for determining the unique group identification based on the user-specific group identifier and the user identity. The group identification means obtains this information from the memory means  9 . The group identification means also comprises transmitting means  19  for transmitting the message to the members of the group. The message can be forwarded directly to the members from the group management unit or may be returned to the mobile exchange  5 , which will forward it to the members.  
         [0061]     As indicated in  FIG. 3  there may be more than one group management unit  7 , for example, one for messaging and one for voice sessions. Several group management units for different types of service can share the database  9 , the identity means  15  and the group identification means  17 .  
         [0062]     Instead of having a separate group management unit, its functions could be implemented in the mobile exchange  5 . The database, or list, could be implemented in a separate unit  9 , as in  FIG. 3 , or included in the unit performing the analysis.  
         [0063]      FIG. 4  shows the steps carried out when a user sends a message to a group defined in the network: 
    Step S 11 : A sending user sends a message to a number in the network. The message is addressed to the user-specific group identifier.     Step S 12 : The message is directed to and received by a node in the network that is responsible for handling group messages. This node can be the exchange  5  or another node  7  in the network, as discussed in connection with  FIG. 3 .     Step S 13 : The node retrieves the user-specific group identifier from the address field of the message and determines the A-number of the sending user.     Step S 14 : The node uses the A-number and the user-specific group identifier to determine the unique group identity, based on information found in a database or other memory means  9  comprising a table like the one shown in table 2.     Step S 15 : The node transmits the message to all members of the group.      
         [0069]      FIG. 5  shows the steps carried out when a user establishes a group connection to a group defined in the network, according to a first embodiment: 
    Step S 21 : A calling user makes a call to a number in the network. The number used is the user-specific group identifier of the desired group.     Step S 22 : The message is directed to and received by a node in the network that is responsible for handling group communication. This node can be the exchange  5  or another node  7  in the network, as discussed in connection with  FIG. 3 .     Step S 23 : The node determines the user-specific group identifier and the A-number of the sending user.     Step S 24 : The node uses the A-number and the user-specific group identifier to determine the unique group identity, based on information found in a database or other memory means  9  comprising a table like the one shown in table 2.     Step S 25 : The node calls all members of the group except the calling user to establish a conference call. All group members who answer the call will be included in the conference call.      
         [0075]     One disadvantage of the method shown in  FIG. 5  is that the sending user may have to pay for all the connections, which may become expensive. It is technically possible to distribute the cost, but this would mean that answering a call would lead to costs.  
         [0076]      FIG. 6  shows the steps carried out when a user establishes a group connection to a group defined in the network, according to a second embodiment: 
    Step S 31 : A calling user makes a call to a number in the network. The number used is the user-specific group identifier of the desired group.     Step S 32 : The message is directed to and received by a node in the network that is responsible for handling group communication. This node can be the exchange  5  or another node  7  in the network, as discussed in connection with  FIG. 3 .     Step S 33 : The node determines the user-specific group identifier and the A-number of the calling user.     Step S 34 : The node uses the A-number and the user-specific group identifier to determine the unique group identity, based on information found in a database or other memory means  9  comprising a table like the one shown in table 2.     Step S 35 : The node prompts all members of the group to connect to the conference bridge used for the conference. The sending user may be connected automatically or may connect actively. The prompt may be sent immediately or the calling user can specify a time, in step S 31 , at which the conference should be set up. The prompt may be in the form of an SMS message telling the users to connect. Alternatively, the prompt may be a call that is ended after only one ringing signal, which may serve as a reminder to the users.      
         [0082]     In this way, since each user actively calls the conference bridge, each user can also be made to pay for his/her own connection.  
         [0083]     The procedures of  FIGS. 5 and 6  may be used for voice and video conferences and for any other type of conference session.  
         [0084]     As discussed above, the memory function and logic functions of units  13 ,  15 ,  17  and  19  in  FIG. 3  can be implemented in other existing nodes in the network, or in dedicated nodes introduced in the network for this purpose. The table can be implemented in several different ways, the simplest solution being a common relational database. Of course, the database may be distributed on several databases.