Cellular communication system and method of operation therefor

摘要

A cellular communication system comprises a core network, a first access network not supporting circuit switched services and a second access network supporting circuit switched services. A user equipment detects that an application using circuit switched communication is initiated and accordingly initiates a reselection from the first to the second access network. The user equipment transmits a location update message to a circuit switch mobile switching center of the core network which in response notifies a mobility management entity for the first access network that the access network reselection has been initiated. In response to the notification the mobility management entity initiates a change of a routing association from being with the first access network to being with the second access network. The invention may e.g. allow improved circuit switched fallback for a 3rd Generation Partnership Project cellular communication system comprising an access network supporting only packet switched services.