10.8 Simultaneous session for MCPTT calls (on-network)

23.3793GPPFunctional architecture and information flows to support Mission Critical Push To Talk (MCPTT)Release 18Stage 2TS

10.8.1 General

An MCPTT client and MCPTT server may use a simultaneous session as defined in 3GPP TS 23.280 [16] for MCPTT calls. The MCPTT client becomes involved in a simultaneous session for MCPTT calls by inviting, joining or accepting more than one MCPTT call, or affiliating to a group.

NOTE: An MCPTT client affiliating to multiple MCPTT groups with active calls will result in the MCPTT client being invited simultaneously to multiple MCPTT calls.

The MCPTT client can also still handle multiple MCPTT calls in parallel at the same time i.e. using multiple dialogs.

The simultaneous session is established during either an originating on-demand call establishment or during pre-established session establishment or a modification of an already established pre-established session or on-demand call.

It is possible to change the prioritisation while the MCPTT client is engaged in multiple MCPTT calls. The setting of the priority can be made at MCPTT call setup or by performing a modification after the MCPTT call is established. This may result in more than one media bearer.