Monitoring (E)PLMN changes for connected mode handover and notifying UE for improving management of CSG whitelists

摘要

When a user equipment (UE) 20 hands-off from a serving cell-A 24 to a target cell-B 28 in a connected/dedicated mode/state it may not perform an update operation (eg. location/registration update). In these circumstances it will not receive an updated Closed Subscriber Group (CSG) whitelist/Allowed CSG List (ACL) 102 for the target cell. If the PLMN and equivalent PLMN (EPLMN) on the target list differ from the whitelist 101 of the original cell problems registering with CSGs (eg. cell-C 30) may occur. For example, registering with CSG not allowed in the new PLMN or not considering CSG that are newly allowed. The invention monitors PLMN changes at handover (HO) and signals the UE when changes occur, possibly using HO commands or system information (SI) messages. The UE may then refrain from reporting new cells until a registration/location update has occurred. In alternatives the target cell may trigger an update and thence supply the target whitelist or the serving cell may provide the target whitelist in HO command or SI message.