Question: In a scenario where a UE is connected via a WLAN link, which network element terminates the PDCP for both control plane and user plane to facilitate a periodic local authentication procedure with the UE?
Option 1: eNB (Evolved Node B)
Option 2: MME (Mobility Management Entity)
Option 3: S-GW (Serving and Packet Data Network Gateway)
Option 4: P-GW (Packet Data Network Gateway)
Explanation: The correct answer is the eNB because it terminates the PDCP for both control and user planes, enabling direct communication between the UE and the eNB for security procedures like periodic local authentication, even when the UE is connected via a WLAN link. Unlike other options, the eNB handles radio interface protocols, making it suitable for this function in this context.