HANDOVER CONTROL IN A MOBILE NETWORK

摘要

A method of handing over an ongoing real-time call involving a mobile station, from a circuit switched bearer in a current cell of a radio access network to a packet switched bearer in a target cell of the same or a different radio access network, the ongoing call having been established using the services of an IP Multimedia Subsystem. The method comprises sending a handover instruction from the radio access network responsible for the current cell or from the mobile station to the IP Multimedia Subsystem, the instruction identifying the target cell, in response to receipt of said instruction at the IP Multimedia Subsystem, establishing a packet switched bearer in the target cell, and transferring the ongoing call from said circuit switched bearer to said packet switched bearer.