Question: In E-UTRAN, where is the mobility information stored that determines which eNBs receive paging requests for a specific UE?
Option 1: In the UE's context within each relevant eNB
Option 2: In a centralized database accessible by all eNBs and MMEs
Option 3: Within the UE itself, transmitted to the network as needed
Option 4: In the serving MME, as part of the UE's MM (Mobility Management) context
Explanation: The correct answer is Option 4 because, according to E-UTRAN architecture, the Mobility Management Entity (MME) manages UE mobility. The MME keeps the Mobility Management (MM) context for each UE, including location information (e.g., Tracking Area(s) - TA(s)) and other mobility data, crucial for routing paging requests to correct eNBs when contacting an idle-mode UE. Thus, the serving MME is the logical storage point for this information, ensuring efficient paging operations.