Question: In an MBMS (Multimedia Broadcast/Multicast Service) architecture, how is data protection typically applied for MBMS user services between the BM-SC (Broadcast Multicast Service Centre) and the UE (User Equipment)?
Option 1: Using asymmetric keys shared between the BM-SC and each individual UE.
Option 2: Based on symmetric keys shared between the BM-SC and the UEs accessing the service.
Option 3: Through a forward error correction code alone, without encryption.
Option 4: By utilizing only header compression for security.
Explanation: The correct answer is Option 2 because, according to the telecom standards for MBMS, data protection (integrity and/or confidentiality) is applied between the BM-SC and the UE using symmetric keys. This method ensures that all authorized UEs can decrypt the protected content without the need for individual key exchanges, which would be required with asymmetric keys. Forward error correction codes are used to protect against packet loss but do not provide encryption-based security. Header compression is a technique to reduce overhead and does not serve as a security measure.