Location updating in communications networks

A cellular telecommunications network, comprising:

• a radio access network comprising a plurality of geographically distributed cells;
• and
• a core network for providing cellular telecommunications network functions to devices registered therewith over a cellular telecommunications network bearer, wherein the devices provide to the radio access network an indicator of the identity of the cell occupied thereby, respective groups of said cells are allocated to respective location regions by the core network, and the core network maintaining a database of the location region occupied by each device,
• wherein the cellular communications network is adapted to provide core network cellular telecommunications network functions to devices registered therewith over a non-cellular telecommunications network bearer via another access network, and wherein, when a device switches from the radio access network to the other access network, the other access network receives the indicator of the identity of the cell occupied by the device and in dependence thereon selects the location region which the device is deemed to occupy by the core network.