Figure 10.6.2.9.3.1-1 illustrates the procedure to initiate a regroup procedure using a preconfigured MCPTT group, where at least one of the groups to be regrouped is configured in a partner MCPTT system. The primary MCPTT system where the preconfigured group regrouping is initiated does not need to be aware of the list of group members belonging to groups whose group home system is the partner MCPTT system. If the group management server in the primary MCPTT of the regroup group shares the necessary security related parameters together with the group configuration of the MCPTT regroup group with the group management server in the partner MCPTT system and the group management server in the partner MCPTT system distributes this configuration including those security parameters to its served MCPTT users according to the procedures in TS 23.280, subclause 10.2.7, the primary MCPTT system does not need to be aware of the list of group members of the preconfigured regroup group that are receiving service in the partner MCPTT system.
The procedure takes place prior to the establishment of a group call to the regroup group.
In this procedure, any gateway MC servers in the primary or partner MCPTT systems are not shown.
Pre-conditions:
MCPTT client 1 is authorized to initiated a preconfigured regroup procedure, and is receiving MCPTT service in the primary MCPTT system of MCPTT client 1.
MCPTT client 2 is an affiliated member of MCPTT group 1 where MCPTT group 1 is defined in the partner MCPTT system and MCPTT client 2 is receiving service in the partner MCPTT system of MCPTT client 1.
The MCPTT group identity and group configuration for the regroup MCPTT group have been preconfigured in MCPTT client 2, and MCPTT client 2 has received the relevant security related information to allow communication in the regroup MCPTT group.
In order to be aware whether the group is regrouped, the MCPTT server is subscribed to the group configuration in GMS.
The authorized user of MCPTT client 1 initiates the regroup procedure, specifying the list of MCPTT groups to be regrouped including MCPTT group 1, the MCPTT group ID of the regroup group and the MCPTT group ID of the group from which configuration information for the regroup group is to be taken.
The MCPTT server checks that MCPTT client 1 is authorized to initiate a preconfigured regroup procedure, and resolves the group identities of the MCPTT groups requested in step 1. The MCPTT server also checks which group members are affiliated to the requested MCPTT groups that are homed in the primary MCPTT system. The MCPTT server identifies any partner systems which are the group home systems for MCPTT groups identified in the list of groups to be regrouped. The MCPTT server may retrieve the configuration for the regroup group from the GMS if that configuration information is not already known to the MCPTT server.
The partner MCPTT server checks the status of any MCPTT groups hosted by that partner MCPTT server, and identifies affiliated group members of any of the identified MCPTT groups (both MCPTT groups that are hosted in the primary MCPTT system and MCPTT groups that are hosted in the partner MCPTT system) that are receiving MCPTT service in the partner MCPTT system, which include MCPTT client 2.
MCPTT client 2 may send the preconfigured regroup response to the partner MCPTT server to acknowledge the regrouping action. This acknowledgement is not sent in response to a multicast transmission of the preconfigured regroup request.
The primary MCPTT server sends the preconfigured regroup response to MCPTT client 1.
After the group regrouping procedure, the regrouping remains in effect until explicitly cancelled by the procedure in clause 10.6.2.9.3.2.
MCPTT client participation in the ongoing regroup persists until the MCPTT client is no longer affiliated to any of the regrouped groups (group 1 or 2 in this procedure).
MCPTT client affiliation to the regroup group may cease when the UE's MCPTT service ceases, e.g. when the UE is powered down, or by performing a log-off operation.
Figure 10.6.2.9.3.2-1 illustrates the procedure to cancel a regrouping that uses a preconfigured MCPTT group where multiple MCPTT systems were involved in the regrouping.
Pre-conditions:
MCPTT client 2 has been regrouped into an MCPTT regroup group, and is receiving MCPTT service in the partner MCPTT system of the regroup group.
MCPTT client 1 is authorized to cancel a regrouping that uses a preconfigured MCPTT group, and is receiving MCPTT service in the primary MCPTT system of the regroup group.
MCPTT client 2 may send the preconfigured regroup remove response to the partner MCPTT server to acknowledge the cancellation of the regrouping function. This acknowledgement is not sent in response to a multicast transmission of the preconfigured regroup cancel request.
Figure 10.6.2.9.3.3-1 illustrates the case where the procedure to initiate a regroup procedure with multiple MCPTT systems using a preconfigured MCPTT group described in subclause 10.6.2.9.3.1 commences, but where the request for the regroup is rejected by the partner MCPTT server, for example because one of the groups hosted by the partner MCPTT server is already regrouped by other group regrouping procedures.
In this procedure, any gateway MC servers in the primary or partner MCPTT systems are not shown.
Pre-conditions:
MCPTT client 1 is authorized to initiated a preconfigured regroup procedure, and is receiving MCPTT service in the primary MCPTT system of MCPTT client 1.
The authorized user of MCPTT client 1 initiates the regroup procedure, specifying the list of MCPTT groups to be regrouped including MCPTT group 1, the MCPTT group ID of the regroup group and the MCPTT group ID of the group from which configuration information for the regroup group is to be taken.
The MCPTT server checks that MCPTT client 1 is authorized to initiate a preconfigured regroup procedure, and resolves the group identities of the MCPTT groups requested in step 1. The MCPTT server also checks which group members are affiliated to the requested MCPTT groups that are homed in the primary MCPTT system. The MCPTT server identifies any partner systems which are the group home systems for MCPTT groups identified in the list of groups to be regrouped. The MCPTT server may retrieve the configuration for the regroup group from the GMS if that configuration information is not already known to the MCPTT server.
The partner MCPTT server checks the status of any MCPTT groups hosted by that partner MCPTT server, and determines that one or more requested MCPTT groups has already been regrouped by another group regrouping procedure.