Group administrator: Group content: Group member:

IP IMS

This clause has an informative description of the IMS group management and its role in a few service examples. Furthermore, example characteristics of the group will be described to give an overview of a group and its management. Group as a concept means a group of persons in this context. Groups can be used by group related services such as conference calls, presence service (c.f. TS 22.141) and messaging (c.f. TS 22.340). This description does not cover requirements for group services themselves but only management of the groups that can be utilized by the group related services. The driver for specifying generic group management is twofold: the same group created by user (or service provider) can be used in many services and same group management functions can be utilised independently of the service being used. In conference call, the control machinery in network would use a group to setup a conference call and distribution of group media. In messaging area, group management could be utilized in chat sessions (Figure 1) and distribution lists (Figure 2). A chat session could be created by joining a group. The message distribution would be handled by the messaging server. The user would send messages to a group and the server would distribute the messages. In the context of presence service, the user could create groups of watchers with the group management features and different presence information would be provided to each of the groups. These are only few examples of possible use of IMS group management and they intend to clarify the scope of group management.

How the group is used within a service is outside the scope of this document and outside the scope of group management. For example, taking part in a chat session, making a conference call and give access to certain attributes of the presence information are all group service specific issues and therefore outside the scope of group management. However, all of them could use groups managed by generic IMS group management. The IMS group management is a common set of actions that can be taken by the group administrator of a group or the group members. Typically, the group consists of members who may have varying rights for configuring or seeing the group properties.

The IMS group management shall provide the ability for users to create groups that can be utilized in context of different services. The following roles are identified for IMS Group Management:

1. group administrator;
   Group administrator shall always have the full set of rights for viewing and managing the group and member properties. Each group shall have at least one group administrator at all times. The group administrator is not a group member by default. The entity creating a group becomes a group administrator.
2. group member; and
   Group member rights shall be assigned by the one who has rights to do that. Group member can be another group.
3. others.
   These are services and entities that are external to the group (i.e. not group administrators or members). They may or may not be able to use or access group content depending on the group specific information.

The groups controlled by the IMS group management shall be associated with

1. a group identifier;
   Each group shall have a globally unique, addressable group identifier, which may be suggested by the group administrator when creating the group. The IMS service provider allocates group identifier. The group identifier is used to refer to a specific group (for example when sending a message, when updating the list of group members…).
2. group specific information; and
   Group specific information is divided into two parts
   1. group information; and
      The group information contains informative text. This could be used for example to describe the type and usage of the group.
   2. group properties.
      Group properties are:
      1. group visibility; and
         Group visibility defines who are able to see the group identifier when performing a search. The following classes exist:
         • only the group administrators; and
         • the group administrators and the group members.
      2. group duration.
         Once created, a group will exist until either:
         • its expiration time; or
         • administratively removed.
3. service specific group information.
   The service specific group information may give additional information on how the group should be used in the context of a specific service. For example, it may indicate that the group shall be used as an access list in the context of the presence service. Detailed description of the service specific group information is not within the scope of this TS. Possible values can be defined by the terminal manufacturer, operator, service provider, or by other specifications. The service specific group information is transparent to the group management.

Requirements for the members are

1. Member identification; and
   It shall be possible to identify the members of the group based on the
   1. member identifier;
      Each single entityshall have a globally unique, addressable identifier(s).
   2. group identifier; or
      Member can be a another group(s) which is referred with a group identifier(s).
   3. commonly known group of entities.
      Member can be any entity that has defined characteristics in the identifier field.
2. group member properties.
   It shall be possible to associate properties for each group member. Such properties are
   1. member rights;
      Each member shall be associated with rights. They define which actions the member is allowed to perform.
   2. anonymity; and
      It shall be possible to hide the member identifier.
   3. service specific member information.
      The service specific member information may give additional information on member in the context of a specific service. For example, it may indicate the screen name of the member in context of chat service. Detailed description of the service specific member information is not within the scope of this TS. Possible values can be defined by the terminal manufacturer, operator, service provider, or by other specifications. The service specific member information is transparent to the group management.

The IMS group management shall provide following capabilities to manage groups. The rights associated to the members control the capabilities they are able to perform. These capabilities are:

1. create a group;
   The entity creating a group becomes a group administrator. The administrator shall not become group member by default when creating a group. Further, when creating a group it shall be possible to
   1. define the members of the group;
   2. define group specific information;
   3. define service specific group information; and
   4. define member properties.
2. delete a group;
   It shall be possible to delete a group.
3. add members to a group;
   It shall be possible to add members to a group.
4. get member list of a group;
   It shall be possible to get the list of all members of a group. In case of nested group only the group identifier of the nested group will be provided.
5. remove members from a group;
   It shall be possible to remove members from a group.
6. get group member identification and group member properties;
   It shall be possible to get member identification and group member properties.
7. modify group member properties;
   It shall be possible to modify group member properties within their rights.
8. get group specific information and service specific group information;
   It shall be possible to get group specific information and service specific group information.
9. modify the group specific information and service specific group information;
   It shall be possible to modify all group specific information and service specific group information.
10. simultaneous access from multiple terminals; and
    It shall be possible to manage groups simultaneously from multiple terminals (e.g. via mobile phone and PC).
11. Search.
    It shall be possible for a user to retrieve the group identifiers of all the groups for which he has the group administrator role within his operator's network.
    It shall be possible for a user to retrieve the group identifiers of all the groups for which he has the group member role within his operator's network. If a group is not visible for its group members, then the group identifier will not be revealed to the user.
    In both cases the search criteria shall be a text string. It shall be possible to use wild cards as part of the text string.

It shall be possible for authorised users and applications to use the group content. Some parts of the group content may not be revealed (e.g. group properties…).

The rights associated with the group members and administrator(s) may grant them access to some notification features described below. It shall be possible for the group members, administrator(s) and authorised users and applications to subscribe to different events concerning the group. When an event occurs the entities interested in that event shall be notified. The notification categories are:

1. change in group specific information;
2. change in service specific group information;
3. change in group members; and
   This includes also the changes in the number of anonymous members.
4. change in group member properties.