10.2 Group management (on-network)

23.2803GPPCommon functional architecture to support mission critical servicesRelease 18Stage 2TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

10.2.1 General

Group management procedures apply to on-network MC service only.

Group creation provides a dedicated MC service group to individual MC service users to enable the required communication for one or multiple MC services. This includes the normal group creation by administrators as well as user regrouping by authorized user/dispatcher.

For an MC service, group regrouping enables dispatchers or authorized users to temporarily combine several MC service groups.

NOTE 1: If an authorized MC service user wants to participate in a new group created by the authorized MC service user, then the authorized MC service user needs to have been included in the new group as a member and have affiliated to the new group.

NOTE 2: If an authorized MC service user wants to participate in a temporary group created by a group regroup operation performed by this authorized MC service user, then the authorized MC service user needs to have been an existing member of and affiliated to at least one of the constituent groups that was part of the associated group regroup operation and have affiliated to the new temporary group.

10.2.2 Information flows for group management

10.2.2.1 Group creation request

Table 10.2.2.1-1 describes the information flow group creation request from the group management client to the group management server.

Table 10.2.2.1-1: Group creation request

Information element	Status	Description
MC service ID list	M	List of MC service IDs that are part of the group to be created corresponding to the list of the configured services (see NOTE 1)
MC service list (see NOTE 2)	O	List of MC services whose service communications are to be enabled on the group.
Proposed MC service group ID	O	MC service group ID proposed for the requested group
MC service group configuration data	O	Configuration data for the requested group (see NOTE 3)
NOTE 1: The MC service ID list can be an empty list. NOTE 2: This information element shall be included in the message for creating a group configured for multiple MC services. NOTE 3: If the MC service group configuration data is not present it can be provided later using the "Store group configuration request" (see subclause 10.1.2.1).

10.2.2.2 Group creation response

Table 10.2.2.2-1 describes the information flow group creation response from the group management server to the group management client.

Table 10.2.2.2-1: Group creation response

Information element	Status	Description
MC service group ID	M (see NOTE)	MC service group ID of the group
Result	M	Indicates success or reason for failure
NOTE: If the Result information element indicates failure then the value of MC service group ID information element has no meaning.

10.2.2.3 Group regroup request (group management client – group management server)

Table 10.2.2.3-1 describes the information flow for the group regroup request from the group management client to the group management server.

Table 10.2.2.3-1: Group regroup request

Information element	Status	Description
MC service group ID list	M	List of MC service group IDs to be combined
Security level (see NOTE 1)	O	Required security level for the temporary group
Priority level	O	Required priority level for the temporary group
MC service list (see NOTE 2)	O	A subset of the common MC service(s) to be applied for the regrouped group
Broadcast regroup	O	Indicates that only an authorized MC service user can transmit on this temporary group.
NOTE 1: Security level refers to the configuration of media and floor control protection parameters as listed in Annex A.4, table A.4-1 NOTE 2: If this information element is not present, all the MC service(s) that are common to the groups being regrouped will be applicable for the regrouped group.

10.2.2.4 Group regroup response (group management server – group management client)

Table 10.2.2.4-1 describes the information flow for the group regroup response from the group management server to the group management client.

Table 10.2.2.4-1: Group regroup response

Information element	Status	Description
MC service group ID	O (see NOTE)	MC service group ID of the temporary group
MC service list	O	List of MC services whose service communications are to be enabled on this temporary group
Result	M	Indicates the success or failure of group regroup
NOTE: Shall be present if the Result information element indicates that the group regroup operation is successful. Otherwise MC service group ID shall not be present.

10.2.2.5 Group regroup teardown request

Table 10.2.2.5-1 describes the information flow group regroup teardown request from the group management client to the group management server.

Table 10.2.2.5-1: Group regroup teardown request

Information element	Status	Description
MC service group ID	M	MC service group ID of the temporary group which is requested to be torn down

10.2.2.6 Group regroup teardown response

Table 10.2.2.6-1 describes the information flow group regroup teardown response from the group management server to the group management client.

Table 10.2.2.6-1: Group regroup teardown response

Information element	Status	Description
MC service group ID	M	MC service group ID of the temporary group
Result	M	Indicates the success or failure of group regroup teardown

10.2.2.7 Group creation notify

Table 10.2.2.7-1 describes the information flow group creation notify from the group management server to the MC service server(s).

NOTE: When group is configured for multiple MC services, the group creation notify message is sent from the group management server to the MC service servers configured for the group.

Table 10.2.2.7-1: Group creation notify

Information element	Status	Description
MC service group ID	M	MC service group ID that was created based on the MC service ID list and the MC services enabled on them
MC service ID list	M	List of MC service IDs that are part of the created group

10.2.2.8 Group regroup notify

Table 10.2.2.8-1 describes the information flow group regroup notify from the group management server to the MC service server.

Table 10.2.2.8-1: Group regroup notify

Information element	Status	Description
MC service group ID list	M	List of constituent MC service group IDs
MC service group ID	M	MC service group ID of the temporary group
MC service list	O	List of MC services whose service communications are to be enabled on this temporary group.
Broadcast regroup	O	Indicates that only an authorized MC service user can transmit on this temporary group.

10.2.2.9 Group regroup teardown notify

Table 10.2.2.9-1 describes the information flow group regroup teardown notify from the group management server to the MC service server.

Table 10.2.2.9-1: Group regroup teardown notify

Information element	Status	Description
MC service group ID	M	MC service group ID of the temporary group which is being torn down

10.2.2.10 Group regroup teardown notification

Table 10.2.2.10-1 describes the information flow group regroup teardown notification between group management servers and from the group management server to the group management client.

Table 10.2.2.10-1: Group regroup teardown notification

Information element	Status	Description
MC service group ID	M	MC service group ID of the temporary group which is torn down

10.2.2.11 Group regroup teardown notification response

Table 10.2.2.11-1 describes the information flow group regroup teardown notification response between group management servers and from the group management client to the group management server.

Table 10.2.2.11-1: Group regroup teardown notification response

Information element	Status	Description
MC service group ID	M	MC service group ID of the temporary group which was torn down
Result	M	Indicates the success or failure

10.2.2.12 Group regroup request (group management server – group management server)

Table 10.2.2.12-1 describes the information flow group regroup request between group management servers.

Table 10.2.2.12-1: Group regroup request

Information element	Status	Description
MC service group ID list	M	List of constituent MC service group IDs belonging to the target group management server

10.2.2.13 Group regroup response (group management server – group management server)

Table 10.2.2.13-1 describes the information flow group regroup response between group management servers.

Table 10.2.2.13-1: Group regroup response

Information element	Status	Description
Result	M	Indicates whether the group regroup was accepted or rejected by the group management server in the partner system
MC service group ID list	M	List of constituent MC service group IDs from group management server of the partner system

10.2.2.14 Group regroup notification

Table 10.2.2.14-1 describes the information flow group regroup notification between group management servers and from the group management server to the group management client.

Table 10.2.2.14-1: Group regroup notification

Information element	Status	Description
MC service group ID list	M	List of constituent MC service group IDs
MC service group ID	M	MC service group ID of the temporary group
Priority level	O	Required priority level for the temporary group
Security level (see NOTE)	O	Required security level for the temporary group
Broadcast regroup	O	Indicates that only an authorized MC service user can transmit on this temporary group.
NOTE: Security level refers to the configuration of media and floor control protection parameters as listed in Annex A.4, table A.4-1

10.2.2.15 Group regroup notification response

Table 10.2.2.15-1 describes the information flow group regroup notification response between group management servers and from the group management client to the group management server.

Table 10.2.2.15-1: Group regroup notification response

Information element	Status	Description
MC service group ID list	M	List of constituent MC service group IDs
MC service group ID	M	MC service group ID of the temporary group
Priority level	M	Required priority level for the temporary group
Security level	M	Required security level for the temporary group
Broadcast regroup	O	Indicates that only an authorized MC service user can transmit on this temporary group.

10.2.2.16 Group information query request

Table 10.2.2.16-1 describes the information group information query request from group management client to group management server.

Table 10.2.2.16-1: Group information query request

Information element	Status	Description
MC service ID	M	The identity of the MC service user who performs the query.
MC service group ID	M	The identity of the MC service group to be queried.
Query type	M	It indicates the query type, i.e., membership or affiliated group members.

10.2.2.17 Group information query response

Table 10.2.2.17-1 describes the information flow group information query response from group management server to group management client.

Table 10.2.2.17-1: Group information query response

Information element	Status	Description
MC service ID	M	The identity of the MC service user who performs the query.
MC service group ID	M	The identity of the MC service group to be queried.
Query type	M	It indicates the query type, e.g., membership or affiliated group members.
Query result	M	The group information retrieved from the group management server based on the query type, i.e., a list of group members or a list of affiliated group member.

10.2.2.18 Group membership update request

Table 10.2.2.18-1 describes the information flow group membership update request from the group management client to the group management server.

Table 10.2.2.18-1: Group membership update request

Information element	Status	Description
MC service group ID	M	Identity of the MC service group
MC service ID list	M	List of identities of the MC service users that are affected by this operation
Operations	M	Add to or delete from the group

10.2.2.19 Group membership update response

Table 10.2.2.19-1 describes the information flow group membership update response from the group management server to the group management client.

Table 10.2.2.19-1: Group membership update response

Information element	Status	Description
MC service group ID	M	Identity of the MC service group
Result	M	Indicates the success or failure for the operation

10.2.2.20 Group membership notification

Table 10.2.2.20-1 describes the information flow group membership notification from the group management server to the MC service server.

Table 10.2.2.20-1: Group membership notification

Information element	Status	Description
MC service group ID	M	Identity of the MC service group
MC service ID list	M	List of identities of the MC service users that are affected by this operation
Operations	M	Add to or delete from the group

Table 10.2.2.20-2 describes the information flow group membership notification from the group management server to the group management client.

Table 10.2.2.20-2: Group membership notification

Information element	Status	Description
MC service group ID	M	Identity of the MC service group
Operations	M	Add to or delete from the group

10.2.2.21 Group deletion request

Table 10.2.2.21-1 describes the information flow group deletion request from the group management client to the group management server.

Table 10.2.2.21-1: Group deletion request

Information element	Status	Description
MC service group ID	M	MC service group ID of the group to delete

10.2.2.22 Group deletion response

Table 10.2.2.22-1 describes the information flow group deletion response from the group management server to the group management client.

Table 10.2.2.22-1: Group deletion response

Information element	Status	Description
MC service group ID	M	Identity of the MC service group requested deleted
Result	M	Indicates success (group no longer exists), or failure (group deletion did not occur, eg. authorization failure).

10.2.2.23 Group deletion notification

Table 10.2.2.23-1 describes the information flow group deletion notification from the group management server to the MC service server, and from the group management server to the group management clients for MC service users which are members of the group.

Table 10.2.2.23-1: Group deletion notification

Information element	Status	Description
MC service group ID	M	MC service group ID has been deleted.

10.2.2.24 Group information provision request

Table 10.2.2.24-1 describes the information flow group information provision request from the group management server in the primary MC system of the MC service group to the group management server in the partner MC system of the MC service group.

Table 10.2.2.24-1: Group information provision request

Information element	Status	Description
MC service group ID	M	MC service group ID of the group
MC service group configuration information	M	Configuration information for the MC service group

10.2.2.25 Group information provision response

Table 10.2.2.25-1 describes the information flow group information provision response from the group management server in the partner MC system of the MC service group to the group management server in the primary MC system of the MC service group.

Table 10.2.2.25-1: Group information provision response

Information element	Status	Description
MC service group ID	M	MC service group ID of the group
Result	M	Indicates success or failure of reception, modification and storage of MC service group configuration information

10.2.2.26 Group information request

Table 10.2.2.26-1 describes the information flow group information request from the group management server in the partner MC system of the MC service group to the group management server in the primary MC system of the MC service group.

Table 10.2.2.26-1: Group information request

Information element	Status	Description
MC service group ID	M	MC service group ID of the group

10.2.2.27 Group information response

Table 10.2.2.27-1 describes the information flow group information response from the group management server in the primary MC system of the MC service group to the group management server in the partner MC system of the MC service group.

Table 10.2.2.27-1: Group information response

Information element	Status	Description
MC service group ID	M	MC service group ID of the group
MC service group configuration information	O (see NOTE 1)	Configuration information for the MC service group
Failure reason	O (see NOTE 2)	Indicates reason for failure to provide MC service group configuration information
NOTE 1: Shall be present if the request can be fulfilled by the group management server in the primary MC system of the MC service group. NOTE 2: Shall be present if the request cannot be fulfilled by the group management server in the primary MC system of the MC service group.

10.2.2.28 Group information subscribe request

Table 10.2.2.28-1 describes the information flow group information subscribe request from the group management server in the partner MC system of the MC service group to the group management server in the primary MC system of the MC service group.

Table 10.2.2.28-1: Group information subscribe request

Information element	Status	Description
MC service group ID	M	MC service group ID of the group

10.2.2.29 Group information subscribe response

Table 10.2.2.29-1 describes the information flow group information subscribe response from the group management server in the primary MC system of the MC service group to the group management server in the partner MC system of the MC service group.

Table 10.2.2.29-1: Group information subscribe response

Information element	Status	Description
MC service group ID	M	MC service group ID of the group
Result	M	Inidicates success or failure of the subscribe request

10.2.2.30 Group information notify request

Table 10.2.2.30-1 describes the information flow group information notify request from the group management server in the primary MC system of the MC service group to the group management server in the partner MC system of the MC service group.

Table 10.2.2.30-1: Group information notify request

Information element	Status	Description
MC service group ID	M	MC service group ID of the group
MC service group configuration information	M	Configuration information for the MC service group

10.2.2.31 Group information notify response

Table 10.2.2.31-1 describes the information flow group information notify response from the group management server in the partner MC system of the MC service group to the group management server in the primary MC system of the MC service group.

Table 10.2.2.31-1: Group information notify response

Information element	Status	Description
MC service group ID	M	MC service group ID of the group
Result	M	Indicates success or failure of the notification request

10.2.3 Group creation

Figure 10.2.3-1 below illustrates the group creation operations by authorized MC service user/ MC service administrator to create a group. It applies to the scenario of normal group creation by an MC service administrator and user regrouping operations by authorized user/dispatcher.

Pre-conditions:

1. The group management client, group management server, MC service server and the MC service group members belong to the same MC system.

2. The administrator/authorized user/dispatcher is aware of the users’ identities which will be combined to form the MC service group.

Figure 10.2.3-1: Group creation

1. The group management client of the administrator/dispatcher/authorized MC service user requests group create operation to the group management server. The identities of the users being combined and the information of the MC services that are enabled on the group shall be included in this message.

NOTE 1: The administrator/dispatcher/authorized MC service user can include a proposed MC service group ID in the group creation request. The proposed MC service group ID can be derived from a set of rules previously agreed between the administrator/dispatcher/authorized MC service user and the group management server. The method by which the the administrator/dispatcher/authorized MC service user obtains the set of rules is outside the scope of the present document.

NOTE 2: The administrator/dispatcher/authorized MC service user can include include configuration data for the requested group. The method by which the administrator/dispatcher/authorized MC service user prepares the configuration data for the requested group is outside the scope of the present document, but it could, for example, be derived from pre-prepared templates available to the administrator/dispatcher/authorized MC service user.

2a. If the proposed MC service group ID information element is not present in the group creation request, the group management server generates the MC service group ID. If the proposed MC service group ID information element is present and acceptable to the group management server, the group management server uses the proposed MC service group ID for the new group. If the proposed MC service group ID information element is present but not acceptable to the group management server, the group management server modifies proposed MC service group ID or generates the MC service group ID or rejects the group creation request.

2b. During the group creation, the group management server stores or creates and stores the information of the group as group configuration data as described in subclause 10.1.5.4. The group management server performs the check on the maximum limit of the total number (Nc6) of MC service group members for the MC service group(s).

3. The group management server may conditionally notify the MC service server regarding the group creation with the information of the group members (if any). During user regroup, the group management server notifies the MC service server regarding the group creation with the information of the temporary group members. The MC service users of the temporary group may be automatically affiliated, if configured on the MC service server.

4. The MC service group members (if any) of the MC service group are notified about the newly created MC service group configuration data.

5. The group management server provides a group creation response to the group management client of the administrator/dispatcher/authorized MC service user. The result information element indicates:

– success (using proposed MC service group ID); or

– success (MC service group ID provided by the group management server); or

– failure (proposed MC service group ID not acceptable); or

– failure for other reason.

10.2.4 Group regrouping

10.2.4.1 Temporary group formation – group regrouping within an MC system

Figure 10.2.4.1-1 below illustrates the group regroup operations to create a temporary group within an MC system. For simplicity, only the case of two MC service groups being combined is represented, but the procedure is the same if more than two groups are combined.

The temporary group formation is applicable only for groups configured with at least one common MC service. The temporary group formation shall be rejected if any of the requested MC services are not common to all MC service groups in the list.

The temporary group created can be a broadcast group or a non-broadcast group. The broadcast regroup is used for one-way communication where only an authorized MCX user is allowed to transmit and all other regroup members are only allowed to receive the communication (e.g. a call from a dispatcher to all regroup members). The non-broadcast regroup is used for two-way communication where all regroup members can transmit and receive (i.e, the regroup group call behaves like a normal non-broadcast group call). The broadcast regroup satisfies the temporary group-broadcast group requirements defined in 3GPP TS 22.180 [2] and is an alternative to the "Temporary group – broadcast group call" procedure (10.6.2.5.3) defined in 3GPP TS 23.379 [16].

Pre-conditions:

1. The group management client, group management server, MC service server and the MC service group members belong to the same MC system.

2. The group management client has retrieved the group configurations of the groups to be regrouped.

Figure 10.2.4.1-1: Group regroup for the groups within the same MC system

1. The group management client of the MC service user requests group regroup operation to the group management server, which is the group management server of one of the groups to be regrouped. The identities of the groups being combined shall be included in this message. The group management client may indicate the security level required for the temporary group. The group management client may indicate the priority level required for the temporary group. The group management client indicates whether the temporary group is a broadcast regroup.

2. The group management server checks whether group regroup operation is performed by an authorized MC service user, based on group policy. The group management server checks whether group1 or group2 is a temporary group. If group 1 or group2 is a temporary group, then the group regrouping will be rejected, otherwise the group regrouping can proceed.

3. The group management server creates and stores the information of the temporary group, including the temporary MC service group ID, the MC service group ID of the groups being combined, the priority level of the temporary group, the security level of the temporary group, and whether the temporary group is a broadcast regroup. If the authorized MC service user does not specify the security level and the priority level, the group management server shall set the lowest security level and the highest priority of the constituent groups. If MC service types of the groups being combined are not identical, group management server determines the overlapping part and stores the MC service list for the temporary group.

4. The group management server notifies the MC service server regarding the temporary group creation with the information of the constituent groups, i.e. temporary MC service group ID, group1’s MC service group ID and group2’s MC service group ID. If MC service list is included, MC service server stores it and provides MC service types accordingly.

5. The group management server notifies the affiliated MC service group members of the constituent MC service groups by sending group regroup notification messages.

6. The affiliated MC service group members of the constituent MC service groups send individual group regroup notification response messages.

7. The group management server provides a group regroup response to the group management client of the authorized MC service user. If MC service list is included, group management client stores it and initiates MC service types accordingly.

8. The affiliated MC service group members of the constituent MC service groups individually request group configuration data from the group management server for the temporary group, as described in clause 10.1.5.2. The group configuration data includes security, priority, and other parameters.

10.2.4.2 Temporary group formation involving multiple MC systems

Figure 10.2.4.2-1 below illustrates the group regroup operations to create a temporary group involving multiple MC systems. For simplicity, only the case of two MC service groups being combined is represented, but the procedure is the same if more than two groups are combined.

NOTE: The temporary group formation is applicable only for groups configured with the same MC service(s).

Pre-conditions:

1. The security aspects of sharing the user information between primary and partner MC systems shall be governed as per the service provider agreement between them. In this case, we consider the partner MC system does not share their users’ information to the primary MC system.

2. The primary MC system consists of the group management server 1 and MC service server (primary). The partner MC system consists of the group management server 2 and MC service server (partner).

3. The group management client of the authorized MC service user belongs to the primary MC system.

4. The group management client has retrieved the group configurations of the groups to be regrouped.

Figure 10.2.4.2-1: Temporary group formation – group regrouping involving multiple MC systems

1. The group management client of the MC service user (e.g. dispatcher) requests group regroup operation to the group management server 1 (which is the group management server of one of the groups to be regrouped). The identities of the groups being combined shall be included in this message. The group management client may indicate the security level required for the temporary group. The group management client may indicate the priority level required for the temporary group. The group management client indicates whether the temporary group is a broadcast regroup.

2. The group management server checks whether group regroup operation is performed by an authorized MC service user, based on group policy. The group management server 1 checks whether group1 is a temporary group. If group1 is a temporary group, then the group regrouping will be rejected, otherwise the group regrouping can proceed.

3. The group management server 1 forwards the group regroup request to the target group management server 2 with the information of the group management server 2 MC service groups.

4. The group management server 2 checks whether group2 is a temporary group. If group2 is a temporary group, then the group regrouping will be rejected, otherwise the group regrouping can proceed.

5. The group management server 2 provides a group regroup response. Due to security aspects concerning sharing information among different MC systems, the group management server 2 does not share the users’ information of the groups under its management to the group management server 1. Any regroup action that violates the rules specified in subclause 10.2.4.4 shall cause a negative response and the current procedure to proceed to step 15.

NOTE: If there is a trust relationship between the primary MC service provider and the partner MC service provider, the partner MC system can share their users’ information to the primary MC system at this step. If there is a change in partner MC system’s constituent group membership, the synchronization procedure with the primary MC system for temporary group is out of scope of this specification

6. The group management server 1 creates and stores the information of the temporary group, including the temporary MC service group ID, off-network information, and the MC service IDs of the groups being combined, the priority level of the temporary group, the security level of the temporary group, and whether the temporary group is a broadcast regroup. If the authorized MC service user does not specify the security level and the priority level, the group management server shall set the lower security level and the higher priority of the constituent groups.

7. The group management server 1 notifies the group management server 2 about its group regroup operation.

8. The group management server 2 acknowledges the group management server 1 and the group management server 2 also stores the information about the temporary group including the temporary MC service group ID, the MC service group IDs of the groups being combined, the priority level of the temporary group and the security level of the temporary group.

9. The group management server 2 notifies the partner MC service server regarding the temporary group creation with the information of the constituent groups i.e. temporary MC service group ID, group1’s MC service group ID and group2’s MC service group ID.

10. Partner MC service server acknowledges the notification from the group management server 2.

11. The group management server 2 notifies the affiliated MC service group members of the constituent MC service groups of the group management server 2, possibly with an indication of a lower security level.

12. The affiliated MC service group members of the constituent MC service groups of the group management server 2 send individual group regroup notification responses to the group management server 2.

13. The group management server 1 notifies the MC service server of the primary system regarding the temporary group creation with the information of the constituent groups, i.e. temporary MC service group ID, group1’s MC service group ID and group2’s MC service group ID. If there are active calls to be merged, then the group management server 1 includes an indication to merge active calls.

14. Primary MC service server acknowledges the notification from the group management server 1.

15. The group management server 1 notifies the affiliated MC service group members of the constituent MC service groups of the group management server 1 by sending group regroup notification messages.

16. The affiliated MC service group members of the constituent MC service groups of group management server 1 send individual group regroup notification responses to the group management server 1.

17. The group management server 1 provides a group regroup response to the group management client of the authorized MC service user (e.g. dispatcher).

18. The affiliated MC service group members of the constituent MC service groups of the group management servers individually request group configuration data from the group management servers for the temporary group, as described in clause 10.1.5.2. The group configuration data includes security, priority, and other parameters.

10.2.4.2a Temporary group tear down within an MC system

Figure 10.2.4.2a-1 below illustrates the tearing down procedure of temporary group created through the group regroup operation. The procedure can be used when, e.g., the specific task for which the temporary group was created has been completed or a busier period occurs. For simplicity, only the teardown case for a temporary group with two MC service groups is represented. The procedure is applicable for more than two groups combined in this temporary group.

Pre-condition:

– The temporary group to be torn down is comprised of multiple MC service groups, and is created through the group regrouping procedure as described in subclause 10.2.4.1.

Figure 10.2.4.2a-1: Temporary group tear down within an MC system

1. The group management client of the MC service user requests group regroup teardown operation to the group management server (which is the group management server where the temporary group is created and stored). The identity of the temporary group (MC service group ID) being torn down shall be included in this message. This message may route through some other signalling nodes.

2. The group management server checks whether group regroup operation is performed by an authorized MC service user, based on group policy. The group management server checks whether the MC service group ID is a temporary group. If MC service group ID is not a temporary group, then the group regroup teardown request will be rejected, otherwise the group regroup teardown can proceed.

3. The group management server tears down the temporary group, i.e., remove the temporary group related information.

4. The group management server notifies the MC service server regarding the temporary group teardown.

5. Any active group call for the temporary group is preserved until it is completed.

6. The group management server notifies the affiliated MC service group members regarding the temporary group teardown by sending the group regroup teardown notification (6a) and receives a group regroup teardown notification response (6b) messages.

7. The group management server provides a group regroup teardown confirmation response to the group management client of the authorized MC service user.

10.2.4.3 Temporary group tear down involving multiple group host servers

Figure 10.2.4.3-1 below illustrates the tearing down procedure of temporary group created through the group regroup operation. The procedure can be used when, e.g., the specific task for which the temporary group was created has been completed or a busier period occurs. For simplicity, only the teardown case for a temporary group with two MC service groups is represented. The procedure is applicable for more than two groups combined in this temporary group.

Pre-conditions:

1. The security aspects of sharing the user information between primary and partner MC systems shall be governed as per the service provider agreement between them. In this case, it considers the partner MC system does not share their users’ information to the primary MC system.

2. The primary MC system consists of the group management server 1 and MC service server (primary). The partner MC system consists of the group management server 2 and MC service server (partner).

3. The group management client of the authorized MC service user belongs to the primary MC system.

4. The temporary group to be torn down is comprised of multiple MC service groups, and is created through the group regrouping procedure as described in subclause 10.2.4.2.

Figure 10.2.4.3-1: Temporary group tear down

1. The group management client of the MC service user requests group regroup teardown operation to the group management server 1 (which is the group management server where the temporary group is created and stored). The identity of the temporary group (MC service group ID) being torn down shall be included in this message. This message may route through some other signalling nodes.

2. The group management server checks whether group regroup operation is performed by an authorized MC service user, based on group policy. The group management server 1 checks whether the MC service group ID is a temporary group. If MC service group ID is not a temporary group, then the group regroup teardown request will be rejected, otherwise the group regroup teardown can proceed.

3. The group management server 1 tears down the temporary group, i.e., remove the temporary group related information.

4. The group management server 1 notifies the primary MC service server regarding the temporary group teardown.

5. Any active group call for the temporary group is preserved until it is completed.

6. The group management server 1 notifies the affiliated MC service group members regarding the temporary group teardown by sending the group regroup teardown notification (6a) and receives a group regroup teardown notification response (6b) messages.

7. The group management server 1 sends a group regroup teardown notification (7a) and receives a group regroup teardown notification response (7b) messages with the group management server 2 – group management server in another MC system regarding the temporary group teardown.

8. The group management server 2 notifies the partner MC service server.

9. The group management server 2 notifies the affiliated MC service group members regarding the temporary group teardown by sending the group regroup teardown notification (9a) and receives a group regroup teardown notification response (9b) messages. Any active group call for the temporary group is preserved until it is completed.

10. The group management server 1 provides a group regroup teardown confirmation response to the group management client of the authorized MC service user.

10.2.4.4 Group regroup rules

To prevent routing issues and complexity related to group regrouping, the following rules shall be applied:

– Group regroup in either single MC system or multiple MC systems can take place if:

– None of the groups to be regrouped are temporary groups; and

– The groups to be regrouped are not already regrouped into another temporary group; and

– If the policy of the MC system does not allow a temporary group to include groups that are currently in emergency state, then regrouping of groups can take place if none of the groups to be regrouped are in emergency state.

– If the policy of the MC system allows a temporary group to include groups from other MC systems, group regrouping containing groups with multiple MC systems can take place if:

– the MC service server (controlling role) for the regrouped group is the MC service server (controlling role) for all MC service groups involved in the regrouping; or

– the MC service server (controlling role) for the regrouped group is an MC service server (controlling role) for at least one of the MC service groups involved in the regrouping; or

– the MC service server (controlling role) for the regrouped group is an MC service server homed by at least one of the MC service groups and the MC system of any involved MC service group allows floor control for the set of regrouped groups to be deferred to the MC service server (controlling role) of the temporary group.

– If the policy of the MC system does not allow a temporary group to include groups from other MC systems, regrouping of groups with members spanning multiple MC systems can take place if:

– the MC service server (controlling role) for the regrouped group is the MC service server (controlling role) for all MC service groups involved in the regrouping; or

– the MC service server (controlling role) for the regrouped group is an MC service server (controlling role) for at least one of the MC service groups involved in the regrouping, and the MC service servers with the controlling roles for all of the groups that are regrouped are within the same MC system.

10.2.5 Membership and affiliation list query

10.2.5.1 General

An MC service user can request the membership or affiliation list on an MC service group regardless the user’s group membership or affiliation.

10.2.5.2 Procedure

Figure 10.2.5.2-1 below illustrates the membership or affiliation list query on an MC service group.

Figure 10.2.5.2-1: membership or affiliation list query

1. The group management client of the MC servicer user requests the membership or affiliation list on the MC service group from the group management server by sending a group information query request. The query type is included.

2. The group management server checks whether the MC servicer user is authorized to perform the query. If authorized, then the group management server retrieve the requested group information based on the query type.

3. The group management server sends a group information query response including the retrieved group information to the group management client.

10.2.6 Group membership

10.2.6.1 Group membership notification

Figure 10.2.6.1-1 illustrates the group membership notification operations to the MC service server(s) and group management clients upon the group membership change at group management server.

Pre-conditions:

1. The group management server and MC service server serve the same MC system.

Figure 10.2.6.1-1: group membership notification

1. The membership of a specific MC service group is changed at group management server.

2. The group management server notifies the MC service server(s) regarding the group membership change with the information of the updated group members.

3. The group management server updates the group management clients of the MC service users who have been added to or removed from the group.

4. The group management client requests to retrieve the relevant group configurations from group management server by procedure defined in subclause 10.1.5.2, if the user is added to the group. If the user is deleted from the group, the locally stored group configurations in the MC service UE may be removed.

10.2.6.2 Group membership update by authorized user

Figure 10.2.6.2-1 below illustrates the group membership update operations by an authorized user/administrator/dispatcher to change the membership a MC service group (e.g. to add or delete group members).

Pre-conditions:

1. The group management server and MC service server serve the same MC system;

2. The initiator of this operation is aware of the current group membership of the MC service group;

3. The Administrator/dispatcher/authorized user is aware of the users’ identities which will be added to or deleted from the MC service group.

Figure 10.2.6.2-1: Group membership update by authorized user

1. The group management client of the administrator/dispatcher/authorized user requests group membership update operation to the group management server.

2. The group management server updates the group membership information. The group management server may perform the check on the maximum limit of the total number (Nc6) of MC service group members.

3. The group management server notifies the MC service server(s) regarding the group membership change with the information of the updated group members.

4. The group members that are added to or deleted from the group by this operation are notified about the group membership change. This step may be followed by retrieving group configurations defined in subclause 10.1.5.2

5. The group management server provides a group membership response to the group management client of the administrator/dispatcher/authorized user.

10.2.7 Group configuration for interconnection

10.2.7.1 Overview

The procedures in the following subclauses describe the process for sharing group configuration from a primary MC system of the MC service group to an interconnected partner MC system of the MC service group where MC service clients receiving MC service in the partner MC system of the MC service group need to make use of the MC service group.

The group management server in the primary MC system of the MC service group provides group configuration information to the group management server in the partner MC system of the MC service group. The group management server in the primary MC system of the MC service group may modify the configuration before providing it to that partner MC system in accordance with policies and requirements within the primary MC system (for example the list of members of the group within the primary MC system or within other partner MC systems might not be exposed to that partner system). The means by which the group management server in the primary system determines which configuration parameters are changed is outside the scope of the present document.

The group management server in the partner MC system of the MC service group may modify the configuration before storing it in accordance with policies and requirements within that MC system (for example the priority of the group within that partner MC system, or permitted locations for service within that partner MC system). The group management server in the partner MC system of the MC service group will be the source of group configuration information to the group management clients of any MC service user who is receiving MC service in the partner MC system of the MC service group and who is defined as a member of the MC service group. The list of groups in the user profile for those group members in the partner MC system of the MC service group will contain the address of this group management server in the partner MC system of the MC service group as the address of the server from which to obtain the MC service group configuration for this MC service group.

The procedures in the following subclauses describe the cases where the provision of configuration information is initiated by the group management server in the primary MC system of the MC service group, and where the configuration is requested by the group management server in the partner MC system of the MC service group. There may be additional proxy servers in between the two group management servers on the edges of one or both MC systems so that each group management server is not aware of the network topology of the other MC system. These additional proxy servers are not shown in these procedures.

10.2.7.2 Primary MC system provides group configuration to the partner MC system

Figure 10.2.7.2-1 below illustrates the case where the primary MC system of the MC service group provides the group configuration to the partner MC system of the MC service group, e.g. due to an action by an administrator or because the primary MC system of some of the MC service group members is the partner MC system of the MC service group.

Preconditions

– The MC service group is defined in its primary MC system.

– One or more MC service group members are defined in the partner MC system.

– The primary MC system of the MC service group has been configured with addressing information for the group management server in the partner MC system of the MC service group.

– The primary MC system of the MC service group is authorized to provide group configuration information to the partner MC system of the MC service group.

NOTE 1: The primary MC system of the MC service group could be configured with an address of the group management server within the partner MC system of the MC service group which is a proxy address, and routing within the partner MC system of the MC service group determines which actual group management server is the correct server to receive the configuration information.

NOTE 2: The group management server within the partner MC system of the MC service group is responsible for providing MC service group configuration information to MC service group members for whom the partner MC system of the MC service group is their serving MC system.

Figure 10.2.7.2-1: Primary MC system provides group configuration to partner MC system

1. The group management server in the primary MC system of the MC service group provides the configuration information related to the MC service group to the group management server in the partner MC system of the MC service group.

NOTE 3: The group management server in the primary MC system can modify the group configuration information in accordance with local policies and local requirements before it is provided to the partner MC system. Such modification is outside the scope of the present document.

2. The group management server in the partner MC system of the MC service group modifies the group configuration information received from the primary MC system of the MC service group according to the partner MC system’s policies and local configuration information.

3. The group management server in the partner MC system of the MC service group stores the modified group configuration.

4. The group management server in the partner MC system may notify the MC service server(s) in the partner MC system of the MC service group of the MC service group configuration.

5. The group management server of the partner MC system of the MC service group responds to the group management server of the primary MC system of the MC service group that the configuration has been received and stored correctly.

10.2.7.3 Partner MC system requests group configuration from the primary MC system

Figure 10.2.7.3-1 below illustrates the case where the partner MC system of the MC service group requests the group configuration from the primary MC system of the MC service group, for example because an MC service user receiving service in the partner MC system of the MC service group has the group configured in the user profile.

Preconditions

– The MC service group is defined in its primary MC system.

– The MC service group is configured in the MC service user profiles of one or more MC service users in the partner MC system of the MC service group.

– At least one of the MC service users in the partner MC system of the MC service group that is listed as an MC service group member of the MC service group has become MC service authorized with the MC service server in the partner MC system of the MC service group.

– The group management server in the partner MC system of the MC service group does not have the configuration for the MC service group stored.

– The partner MC system of the MC service group has been configured with addressing information for the group management server in the primary MC system of the MC service group.

– The partner MC system of the MC service group is authorized to request group configuration information from the primary MC system of the group.

NOTE 1: The partner MC system of the MC service group could be configured with an address of the group management server within the primary MC system of the MC service group which is a proxy address, and routing within the primary MC system of the MC service group determines which actual group management server is the correct server to provide the configuration information.

NOTE 2: The group management server within the partner MC system of the MC service group is responsible for providing group configuration information to MC service group members for whom the partner MC system of the MC service group is their serving MC system.

Figure 10.2.7.3-1: Partner MC system requests group configuration from primary MC system

1. The MC service server in the partner MC system of the MC service group requests the group configuration information from the group management server in the partner MC system of the MC service group.

2. The group management server in the partner MC system of the MC service group requests the group configuration from the group management server in the primary MC system of the MC service group.

3. The group management server in the primary MC system of the MC service group provides the requested group configuration information.

4. The group management server in the partner MC system of the MC service group modifies the group configuration information received from the primary MC system of the MC service group according to the partner MC system’s policies and local configuration information.

5. The group management server in the partner MC system of the MC service group stores the modified group configuration.

6. The group management server in the partner MC system notifies the MC service server(s) in the partner MC system of the MC service group of the MC service group configuration.

10.2.7.4 Partner MC system subscribes to group configuration

The procedure for subscription from the group management server in the partner system for group configuration information to the group management server in the primary MC system of the MC service group is shown in figure 10.2.7.4-1.

Pre-conditions:

– The MC service group is defined in its primary MC system.

– One or more MC service group members are defined in the partner MC system.

– The GMS in the partner MC system of the MC service group has received group configuration information from the GMS in the primary MC system of the MC service group.

Figure 10.2.7.4-1: Subscription from partner MC system to primary MC system for MC service group configuration

1. The group management server in the partner MC system of the MC service group subscribes to the group configuration information stored in the group management server in the primary MC system of the MC service group.

2. The group management server in the primary MC system of the MC service group provides a group information subscribe response to the group management server in the partner MC system of the MC service group indicating success or failure of the request.

10.2.7.5 Primary MC system notifies group configuration

The procedure for notification of group configuration information from the group management server in the primary MC system of the MC service group to the group management server in the partner MC system of the MC service group is shown in figure 10.2.7.5-1.

Pre-conditions:

– The group management server in the partner MC system of the MC service group has subscribed to the group configuration information for the MC service group in the group management server in the primary MC system of the MC service group.

– The group management server in the primary MC system of the MC service group has received and stored new group configuration information for the MC service group, or the group management server in the primary MC system of the MC service group has generated and stored new key material, or both of these have occurred.

Figure 10.2.7.5-1: Notification of group configuration information to partner MC system of MC service group

1. The group management server in the primary MC system of the MC service group provides the notification to the group management server in the partner MC system of the MC service group, Optionally, the notify group configuration request may contain group related key material for the group management client.

2. The group management server in the partner MC system of the MC service group provides a notify group information notify response to the group management server in the primary MC system of the MC service group indicating the success or failure of the notification.

Following completion of the notification procedure, the group management server in the partner MC system of the MC service group stores the group configuration information and any key material provided.

10.2.8 Group deletion

Figure 10.2.8-1 below illustrates the group deletion procedure by an authorized MC service user/ MC service administrator to delete a group in the primary MC system. Any actions taken by the group management clients on the UE after receiving the group deletion notification are outside the scope of this procedure.

Pre-conditions:

1. The group management clients, the group management server, and the MC service server belong to the same MC system.

2. The group management client (originator) is for an authorized user with authorization to perform the group deletion.

Figure 10.2.8-1: Group deletion

1. The group management client (originator) of an authorized MC service user sends a group deletion request to the group management server.2. The group management server checks whether the MC service user is authorized to perform the group deletion operation. For an authorized MC service user, the group management server will proceed to delete the group and move to step 3. If the MC service user is not authorized, then the group management server will not delete the group and move to step 5 sending a group deletion response failure.

3. The group management server sends a group deletion notification to the MC service server of the group as well as any MC service servers subscribed to the group. When a group is configured for multiple MC services, the group deletion notification is sent from the group management server to all MC service servers subscribed to the group. Affiliations to the deleted group will be removed.

NOTE 1: Any actions taken by the MC service server upon receiving the group deletion notification are not shown in this procedure. Whether ongoing calls associated with the group deletion are impacted is left to implementation.

4. The group management server sends the group deletion notification to group management clients for all group members of the deleted group. MC service client affiliations to the deleted group are removed.

NOTE 2: It is assumed in this flow that the group management client (originator) is not a member of the group, so it does not receive a group deletion notification.

5. The group management server sends a group deletion response to the group management client (originator).