Authorising a user device comprising a subscriber identity module to access wireless networks other than a cellular network

Authorising a user device comprising a subscriber identity module (SIM) to access wireless networks other than a cellular network, in order to reduce the data traffic on the cellular networks due to the proliferation of smart phones and the provision of mobile broadband for laptop and tablet computer devices. Data-related traffic on the cellular networks may be offloaded to nearby wireless networks (WLAN, WMAN, etc).