Question: What is the composition of a Public Land Mobile Network (PLMN) Identifier (PLMN-Id) used for unique identification across the Iu interface between the Core Network (CN) and Universal Terrestrial Radio Access Network (UTRAN)?
Option 1: PLMN-Id = Location Area Code (LAC) || Cell Identity (CI)
Option 2: PLMN-Id = Mobile Country Code (MCC) only
Option 3: PLMN-Id = Mobile Country Code (MCC) || Mobile Network Code (MNC)
Option 4: PLMN-Id = Service Area Code (SAC) || RNC Identifier
Explanation: The correct composition of a PLMN Identifier (PLMN-Id) for uniquely identifying a Public Land Mobile Network is the concatenation of the Mobile Country Code (MCC) and the Mobile Network Code (MNC). This ensures global uniqueness, with MCC identifying the country and MNC pinpointing the specific mobile network within that country. This identifier is crucial for operations across the Iu interface between the CN and UTRAN, facilitating proper routing and management of mobile communications.