Patent ID: 8509785

Claim:
A method in a network node of a core network of a cellular network comprising at least one femtocell and at least one macrocell, wherein an area covered by the cellular network is divided into a plurality of macro tracking areas, TAs, wherein the network node is configured to be aware of one or more pre-determined home base stations serving one or more pre-determined femtocells which a UE connected to the cellular network is allowed to access, the method comprising: obtaining an association of each of the pre-determined femtocells with a specific femto layer TA, retrieving information to obtain an association between the femto layer TA(s) and its (their) neighboring or covering macro layer TAs, creating a list per UE, including macro layer TAs and/or femto layer TAs in which the UE can move without performing a tracking area update, based on the association of each of the pre-determined femtocells with a femto layer TA used in the pre-determined femtocell and the obtained association between the femto layer TAs and their neighboring or covering macro layer TAs, and sending the created list.