Network discovery and selection based upon a hierarchical policy of network information

A wireless communication unit (UE) 105 is capable of communicating with a plurality of communication networks 110, 150 in a cellular communication system 100, each communication network 110, 150 employing a respective radio access technology (RAT), e.g. UTRAN, GERAN, LTE, Mobile WiMAX. The UE 105 receives a message from a network device, e.g. an Access Network Discovery and Selection Function (ANDSF) 140, in the cellular communication system 100 and determines, from the received message, a hierarchical policy of network information that applies to the RATs, e.g. a global policy of network information associated with the RATs in the geographical area of the cellular communication system 100 or a local policy of network information applied on a routing area (RA) / tracking area (TA) basis. Hence, network discovery and selection may be performed by the UE 105 according to the global and/or local policies of network information provided by the ANDSF network device 140.