HANDOVER OF PRIORITY CALLS FROM A CIRCUIT SWITCHED ACCESS NETWORK WITH SINGLE RADIO VOICE CALL CONTINUITY

摘要

A method is provided of handing over a priority call with Single Radio Voice Call Continuity, SRVCC. The priority call is handed over from a User Equipment, UE, accessing an IP Multimedia Subsystem, IMS, network via a Circuit Switched, CS, access network to a target Packet Switched, PS, access network thereby establishing a priority IMS session. The priority call has a specified CS priority level. The method includes sending a hand over request from the CS access network towards the PS access network and the IMS network to transfer the priority call. A PS priority level for the session in the PS network is determined based on the specified CS priority level. Bearer resources for the IMS session are allocated. The bearer resources are based, at least in part, on the PS priority level. The call is transferred to the IMS session over the PS access network.