Question: What is the primary purpose of the Service Area Identity (SAI) in a cellular network, and how is it typically composed?
Option 1: To uniquely identify a cell tower; Composed of MCC + MNC + LAC + SAC.
Option 2: To authenticate user equipment; Composed of IMSI + IMEI + LAC.
Option 3: To manage Quality of Service (QoS); Composed of QCI + PCI + eNB ID.
Option 4: To bill roaming subscribers; Composed of VPLMN ID + HPLMN ID + MSISDN.
Explanation: The Service Area Identity (SAI) is primarily used to uniquely identify a geographical area consisting of one or more cells within the same location area, aiding in location services for Mobile Stations relative to the Core Network. The composition of SAI as MCC + MNC + LAC + SAC accurately reflects its purpose and structure for identifying service areas.