This is a way to share the network resources among multiple operators. The same network infrastructure is used to transmit/receive for different operators.
The MIB contains a list of multiple PLMN Identities. The UE reads the MIB and selects a PLMN to register to, based on its subscription.
MIB Contents:
.........
Common PLMN
..........
mibPLMN-Identity BOOLEAN,
multiplePLMNs SEQUENCE (SIZE(1..5))
- PLMN1
- PLMN2
PLMN1, PLMN2, etc are the multiple PLMNs in the cell. If mibPLMN-Identity is st to TRUE, the supporting UE can include the common PLMN identity also in the list of PLMNs to choose from. If it is FALSE, the supporting UE does not attempt to register on the common PLMN.
The terms associated with MOCN and their definitions are:
Conventional network: 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.
Common PLMN: 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
(MSC/SGSNs) are also shared.
Multi-Operator Core Network: A network-sharing configuration in which only the RAN is shared.
Non-supporting UE: 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. In other specifications, the term "network sharing non-supporting
UE" may be used.
Supporting UE: 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.
Further Reading: 23.251