Gateway emulating presence of mobile phone

Text message calls, addressed to a predetermined cellular telecommunications directory number, are routed over a cellular telecommunications network to a service application 15. Routing data associated with the directory number is stored by the network in order to emulate the presence of a cellular communications device, such that calls addressed to the directory number are correctly routed to the service application. A "virtual" location register 66 contains virtual mobile device data and virtual network infrastructure data, to enable a standard interface 61 to request and respond to requests for this data as if a real cellular device were present. A virtual mobile gateway 27 provides the required virtual network and virtual mobile device data to populate the virtual location register 66, and to route the signalling and data traffic over an interface 68 to a gateway application 64 serving the required application 15.