A system is disclosed in which a base station initiates a handover of a mobile relay node associated with the base station. The base station obtains information that identifies at least one further base station, and that indicates that the at least one further base station is capable of providing donor services to the mobile relay node. When the base station determines that the mobile relay node requires handover, it selects, from at least one cell of the at least one further base station identified by the obtained information, a target cell for handover of the mobile relay node, and performs handover of the mobile relay node to the selected target cell.