Question: What indicates a successful outgoing intra-eNB handover when Discontinuous Reception (DRX) is used in an Evolved Universal Terrestrial Radio Access Network (E-UTRAN)?
Option 1: Receipt of a RRC message RRCConnectionReconfiguration sent from the eNB to the UE.
Option 2: Receipt of a RRC message RRCConnectionReconfigurationComplete sent from the UE to the target (=source) eNB, or receipt at the source eNB of UE CONTEXT RELEASE over the X2 from the target eNB following a successful handover when DRX is used.
Option 3: Receipt of UE CONTEXT RELEASE COMMAND at the target eNB following a successful handover when DRX is not used.
Option 4: Receipt of RRC message RRCConnectionReconfigurationComplete sent from the eNB to the UE, and then receipt of UE CONTEXT RELEASE over the X2 from the source eNB.
Explanation: The correct answer is Option 2 because it accurately describes the indicators for a successful outgoing intra-eNB handover when DRX is used in an E-UTRAN. These indicators include the receipt of a RRC message RRCConnectionReconfigurationComplete sent from the UE to the target (=source) eNB, or the receipt at the source eNB of UE CONTEXT RELEASE over the X2 from the target eNB following a successful handover when DRX is used.