Question: Which entity typically initiates the Initial Context Setup function in an E-UTRAN to facilitate a swift Idle-to-Active transition for a User Equipment (UE)?
Option 1: Mobility Management Entity (MME)
Option 2: Evolved Node B (eNB)
Option 3: Serving Gateway (S-GW)
Option 4: Packet Data Network Gateway (P-GW)
Explanation: The correct answer is the Mobility Management Entity (MME) because it plays a crucial role in managing the UE's context and signaling connections. Initiating the Initial Context Setup from the MME ensures seamless coordination with other network elements, like the eNB, for efficient Idle-to-Active transitions, aligning with its responsibility for UE mobility and session management in the E-UTRAN architecture.