Question: In E-UTRAN, how does a target eNB typically retrieve UE radio capabilities when the RACS Indication is set?
Option 1: Directly from the UE through dedicated signaling
Option 2: Based on information received from the target MME, as part of the S1AP protocol
Option 3: By querying a centralized database within the EPC (Evolved Packet Core)
Option 4: Through broadcast messages sent by neighboring eNBs
Explanation: The correct answer is Option 2 because, according to the specified behavior for RACS Indication in E-UTRAN, when this indication is set, it signifies that the target eNodeB (eNB) can obtain the User Equipment’s (UE) radio capabilities from information provided by the target Mobility Management Entity (MME). This process leverages existing signaling pathways within the S1 Application Protocol (S1AP), ensuring efficient use of network resources and streamlined communication between E-UTRAN elements.