Patent ID: 8219117

Claim:
In a wireless network which comprises a plurality of base stations that includes at least a first subnet and a second subnet of base stations and a plurality of access network gateways, a method for tracking and/or paging a mobile terminal, wherein the method comprises the steps of: providing a mobile terminal located within the first subnet of said wireless network and wherein said mobile terminal is in an active mode and communicating with a first base station in the first subnet of base stations; selecting a first access network gateway out of said plurality of access network gateways to be an anchor gateway for location and/or paging control associated with said mobile terminal; providing said mobile terminal with information that allows identifying said anchor gateway; following a period during which said mobile terminal has been in an idle mode, receiving a message at a second base station from said mobile terminal, said message being for carrying out a location update for said mobile terminal and comprising an indication that allows identifying said anchor gateway, said second base station being located in the second subnet; informing said anchor gateway by said second base station that a request to perform said location update has been made; and upon receiving, at said anchor gateway the request for a location update of said mobile terminal, said anchor gateway provides said second base station with information required for verifying the identity of said mobile terminal and/or for retaining the security integrity of said second base station while carrying out location update of said mobile terminal.