Method for selecting a core network

摘要

A method ( 200 ) for selecting a core network for a communication device includes the steps of: receiving ( 220 ) at least one core network identifier; selecting ( 230 ) a core network identifier; setting ( 215 ) an indicator to indicate whether a substitute core network is allowed; determining ( 240 ) whether the selected core network identifier corresponds to a shared network; forming a registration request message containing the selected core network identifier; including ( 243 ) the indicator in the registration request message; and transmitting the registration request message.