Some embodiments provide a mobile relay node, RN, (16) with complete and valid neighbor cell information. The RN (16) requests this information from a donor base station (12) upon detecting a defined condition characteristically indicating that movement of the RN (16) has rendered previously obtained neighbor cell information incomplete or invalid. The RN (16) may generate the request to identify cells (18) currently neighboring the mobile cell (20). The donor base station (12) may then provide the RN (16) information that more specifically pertains to the mobile cell's neighbors, rather than generally pertaining to the donor cell's neighbors. Other embodiments compensate for the RN's incomplete or invalid neighbor cell information. These embodiments permit the RN (16) to identify a target cell (18) with a non-unique cell identifier in a handover message sent to the donor base station (12). The donor base station (12) resolves this non-unique identifier and replaces it with the corresponding unique identifier for sending the message towards the target cell (18).