Abstract: A mobile cellular telephone network is arranged such that calls are routed to a selected member of a group of handsets associated with a single number. The handset to which the call is routed is selected according to the current locations of the handsets, preference being given to handsets currently located within a predetermined cell or group of cells. This allows calls to be automatically routed to whichever handset is currently located in a cell where call tariffs are most favorable. Diversion arrangements can be made to allow calls to be re-routed when none of the handsets is detected within the specified group of cells.