PLMN
A Public Land Mobile Network (PLMN) is a network established and operated by an Administration or RPOA for the specific purpose of providing land mobile communication services to the public. It provides communication possibilities for mobile users.
For communications between mobile and fixed users, interworking with a fixed network is necessary.
A PLMN may provide service in one, or a combination, of frequency bands. As a rule, the borders of a country limit a PLMN. Depending on national regulations there may be more than one PLMN per country. A relationship exists between each subscriber and his home PLMN (HPLMN). If communications are handled over another PLMN, this PLMN is referred to as the visited PLMN (VPLMN).
A PLMN is identified by the Mobile Country Code (MCC) and the Mobile Network Code (MNC). Each operator providing mobile services has its own PLMN. PLMNs interconnect with other PLMNs and Public switched telephone networks (PSTN) for telephone communications or with internet service providers for data and internet access of which links are defined as interconnect links between providers.
PLMN Area
The PLMN area is the geographical area in which a PLMN provides communication services according to the specifications to mobile users. In the PLMN area, the mobile user can set up calls to a user of a terminating network. The terminating network may be a fixed network, the same PLMN, another PLMN or other types of PLMN.
Terminating network users can also set up calls to the PLMN.
The PLMN area is allocated to a PLMN. In general the PLMN area is restricted to one country. It can also be determined differently, depending on the different telecommunication services, or type of MS.
If there are several PLMNs in one country, their PLMN areas may overlap. In border areas, the PLMN areas of different countries may overlap. Administrations will have to take precautions to ensure that cross border coverage is minimized in adjacent countries unless otherwise agreed.