Providing an IMS Voice Session via a Packet Switch Network and an Emergency Voice Session via a Circuit Switch Network

摘要

A method of providing an availability of an execution of an Internet Protocol Multimedia Subsystem voice session via a packet switched capable radio access network of an Internet Protocol Multimedia Subsystem based communication network (100) with a terminal (102) is described. The communication network (100) comprises a packet switched domain associated with the packet switched capable radio access network. The communication network (100) supports an Internet Protocol Multimedia Subsystem voice session via the packet switched capable radio access network. The terminal (102) supports an Internet Protocol Multimedia Subsystem voice session via the packet switched capable radio access network and an Internet Protocol Multimedia Subsystem emergency voice session via the packet switched capable radio access network. The method is executed by a control node (112) of the packet switched domain (106). The method comprises sending (264) instruction information to the terminal (102). The instruction information instructs the terminal (102) to execute an Internet Protocol Multimedia Subsystem voice session via the packet switched capable radio access network without regard to whether the communication network (100) having indicated support of an emergency session related data transmission via the packet switched capable radio access network and the packet switched domain (106). The latter enable an improved usage of capabilities of the terminal (102).