US Patent 11539683 Operation related to user equipment using secret identifier

A method performed by a network node of a serving public land mobile network, PLMN, associated with a user equipment, UE, comprising: obtaining a secret identifier that uniquely identifies the UE, wherein the secret identifier is a secret that is shared between the UE and at least a home PLMN of the UE and that is shared by the home PLMN with the network node; and performing an operation related to the UE using the secret identifier. Other methods, computer programs, computer program products, network nodes and a serving PLMN are also disclosed.