Question: What is the primary purpose of using a Temporary Mobile Subscriber Identity (TMSI/P-TMSI) in a cellular network?
Option 1: To authenticate users on the core network
Option 2: To identify users on the radio access link within a specific location or routing area
Option 3: To encrypt data transmission between the user equipment and the base station
Option 4: To assign IP addresses to user equipment
Explanation: The TMSI/P-TMSI is used to identify users on the radio access link within a specific location or routing area, allowing for more efficient use of resources and improved security. This is because the TMSI/P-TMSI has local significance only in the area where the user is registered, and must be accompanied by a Location Area Identification (LAI) or Routing Area Identification (RAI) when used outside that area to avoid ambiguities.