Content for  TS 23.280  Word version:  19.3.1

Figure 10.15.3.3.1-1 illustrates the procedure to initiate a group regroup procedure using a preconfigured MC service group, where at least one of the groups to be regrouped is configured in a partner MC system. The primary MC 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 MC system. If the group management server in the primary MC system of the MC service regroup group shares the necessary security related parameters together with the group configuration of the preconfigured MC service group with the group management server in the partner MC system and the group management server in the partner MC system distributes this configuration including those security parameters to its served MC service users according to the procedures in subclause 10.2.7, the primary MC system does not need to be aware of the list of group members of the MC service regroup group that are receiving service in the partner MC system. The procedure takes place prior to the establishment of a group call to the MC service regroup group. In this procedure, any gateway MC servers in the primary or partner MC systems are not shown. Pre-conditions:

• MC service client 1 is authorized to initiated a preconfigured regroup procedure, and is receiving MC service in the primary MC system of MC service client 1.
• MC service client 2 is an affiliated member of MC service group 1 where MC service group 1 is defined in the partner MC system and MC service client 2 is receiving service in the partner MC system of MC service client 1.
• The preconfigured MC service group have been preconfigured in MC service client 2, and MC service client 2 has received the relevant security related information to allow communication in the MC service regroup group.
• In order to be aware whether the group is regrouped, the MC service server is subscribed to the group configuration in the GMS.
• The GMS has subscribed to group dynamic data from the MC service server within the same MC system using the procedures defined in subclause 10.1.5.6

After the group regrouping procedure, the regrouping remains in effect until explicitly cancelled by the procedure in clause 10.15.3.3.3. MC service client participation in the ongoing regroup persists until the MC service client is no longer affiliated to any of the regrouped groups (group 1 or 2 in this procedure). MC service client affiliation to the regroup group may cease when the UE's MC service ceases, e.g. when the UE is powered down, or by performing a log-off operation.

Figure 10.15.3.3.2-1 illustrates the procedure to initiate a user regroup procedure using a preconfigured MC service group, where at least one of the MC service users to be regrouped is homed in a partner MC system. It is assumed that the group management server in the primary MC system of the MC service regroup group shares the necessary security related parameters together with the group configuration of the preconfigured MC service group with the group management server in the partner MC system and the group management server in the partner MC system distributes this configuration including those security parameters to its served MC service users according to the procedures in subclause 10.2.7. The procedure takes place prior to the establishment of a group call to the MC service regroup group. In this procedure, any gateway MC servers in the primary or partner MC systems are not shown. Pre-conditions:

• MC service client 1 is homed in the primary MC system and is receiving service in the primary MC system.
• MC service client 2 is homed in the partner MC system and is receiving service in the partner MC service system of MC client 1.
• The MC service group identity and group configuration for the preconfigured MC service group have been preconfigured in MC service client 2, and MC service client 2 has received the relevant security related information to allow communication in the MC service regroup group.
• MC service client 1 is authorized to initiate a preconfigured user regroup procedure.
• MC service client 1 is aware of a suitable preconfigured group whose configuration has been preconfigured in the MC service UEs of the MC service users who will be regrouped.

Figure 10.15.3.3.3-1 illustrates the procedure to cancel a group or user regroup that uses a preconfigured MC service group where multiple MC systems were involved in the regrouping. Pre-conditions:

• MC service client 2 has been regrouped into the MC service regroup group, and is receiving service in the partner MC system of the regroup group.
• MC service client 1 is authorized to cancel a regrouping that uses a preconfigured MC service group, and is receiving service in the primary MC system of the regroup group.
• The GMS has subscribed to group dynamic data from the MC service server within the same MC system using the procedures defined in subclause 10.1.5.6.

Figure 10.15.3.3.4-1 illustrates the case where the procedure to initiate a group regroup with multiple MC systems using a preconfigured MC service group described in subclauses 10.15.3.3.1 commences, but where the request for the regroup is rejected by the partner MC service server. The rejection can occur, for example because one of the groups hosted by the partner MC service server is already regrouped by other group regrouping procedures. In this procedure, any gateway MC servers in the primary or partner MC systems are not shown. Pre-conditions:

• MC service client 1 is authorized to initiated a preconfigured regroup procedure, and is receiving MC service in the primary MC system of MC service client 1.
• In order to be aware whether the group is regrouped, the MC service server within the same MC system is subscribed to the group configuration in the GMS.