The PLMN identity combines a three-digit Mobile Country Code with a two-or-three-digit Mobile Network Code to uniquely identify a mobile operator within a country. Every cell broadcast, AMF instance, and network slice is associated with at least one PLMN ID. In 5G a single cell can broadcast multiple PLMN IDs simultaneously, which is the mechanism that enables Multi-Operator Core Network sharing. This allows two or more operators to share the same radio infrastructure while maintaining logically separate core networks, reducing deployment costs in rural or underserved areas.