Question: What triggers the counting of successful outgoing inter-frequency handovers without using measurement gaps in E-UTRAN?
Option 1: Receipt of a RRC message RRCConnectionReconfigurationComplete sent from the UE to the target eNB/RN.
Option 2: Receipt of a S1AP message HandoverRequest at the source eNB.
Option 3: Receipt of a X2AP message Load Information at the target eNB.
Option 4: Receipt of a NAS message Attach Accept at the MME.
Explanation: According to the 3GPP specification, the counting of successful outgoing inter-frequency handovers without using measurement gaps in E-UTRAN is triggered by the receipt of a RRC message RRCConnectionReconfigurationComplete sent from the UE to the target eNB/RN. This indicates that the handover has been successfully completed and the UE has reconfigured its connection with the new cell.