Radio access technology selection in telecommunications system

A telecommunications system operable to provide a facility for mobile communications to a mobile device, the system comprising:

• a core network including a policy control function,
• an access control function, and
• a plurality of radio access networks,
• each radio access network operable to communicate data to and from the mobile device in accordance with one of a plurality of radio access technologies, and in response to an attach request from the mobile device requesting a connection via a chosen radio access technology with the core network, the core network is operable to establish a connection with the mobile device via at least one of the plurality of radio access technologies for communicating data to and from the mobile device, wherein
• the access control function is operable to identify the mobile device requesting the connection with the core network and to communicate with the policy control function;
• and,
• in accordance with one or more access control criteria, to
• generate an attach response indicating whether the mobile device may establish the connection with the chosen radio access technology and
• the core network is operable to communicate an attach response to the mobile device via the radio access network via which the mobile device has requested the connection;
• wherein the access control criteria includes access policy conditions defined by the policy control function.