For the purposes of the present document, the following terms and definition below apply. Terms and definitions not defined below can be found in TR 21.905
A PLMN consisting of radio access network and core network, by which only one serving operator provides services to its subscriber. Subscribers of other operators may receive services by national or international roaming.
The PLMN-id indicated in the system broadcast information as defined for conventional networks, which non-supporting UEs understand as the serving operator.
Core network operator:
An operator that provides services to subscribers as one of multiple serving operators that share at least a radio access network. Each core network operator may provide services to subscriber of other operators by national or international roaming.
Gateway Core Network:
A network sharing configuration in which parts of the core network (MSCs/SGSNs/MMEs) are also shared.
Multi-Operator Core Network:
A network-sharing configuration in which only the RAN is shared.
A UE that does not support network sharing in the sense that it ignores the additional broadcast system information that is specific for network sharing for 3GPP UTRAN and GERAN. In other specifications, the term "network sharing non-supporting UE" may be used.
A UE that supports network sharing in the sense that it is able to select a core network operator as the serving operator within a shared network. In other specifications, the term "network sharing supporting UE" may be used.
With regard to SRVCC from CS to PS, this Anchor PLMN points to the PS domain operator in which the voice media is anchored in Access Transfer Gateway as part of the SRVCC procedure.