Question: What is the primary purpose of allocating a Temporary Mobile Subscriber Identity (TMSI) to a visiting mobile subscriber in a GSM/UMTS/EPS system?
Option 1: To provide a permanent, globally unique identifier for each mobile subscriber.
Option 2: To enable direct communication between the Mobile Station (MS) and the Home Location Register (HLR).
Option 3: To facilitate handover procedures between different Mobile Network Operators.
Option 4: To support the subscriber identity confidentiality service by concealing the International Mobile Subscription Identity (IMSI).
Explanation: The allocation of a TMSI is primarily aimed at supporting the subscriber identity confidentiality service. By using a TMSI, the permanent and globally unique IMSI can be kept confidential over the radio interface, enhancing user privacy. This is crucial in wireless communications to protect subscribers' identities from potential eavesdropping or tracking attempts.