Providing an IMS voice session via a packet switch network and an emergency voice session via a circuit switch network

摘要

A communication network comprises a packet switched domain associated with a packet switched capable radio access network and supports an Internet Protocol Multimedia Subsystem voice session via the packet switched capable radio access network. The terminal 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. A method is executed by a control node of the packet switched domain and comprises sending instruction information to the terminal. The instruction information instructs the terminal to execute an Internet Protocol Multimedia Subsystem voice session via the packet switched capable radio access network without regard to whether the communication network has indicated support of an emergency session related data transmission via the packet switched capable radio access network and the packet switched domain.