An apparatus is provided that includes a controller configured to detect at least one predefined event and, in response to the detection of the predefined event, to trigger a handover of the communication device from a first access system to a second access system on the basis of the power efficiency of the second access system. The predefined event may be in communications between a communication device and a communication system and/or may be in relation to power consumption. Corresponding communication systems, methods and controllers are also provided.