In a heterogeneous network handover situation, a mobile terminal (110) is initially in wireless communication with a source network (130). The mobile terminal transmits, to a target network (170), a target network overhead update request message (315, 325) containing location information of the mobile terminal and receives, from the target network, a target network overhead update response message (317, 327) containing overhead message information for the target network and optionally other information such as handover willingness, network loading, and QoS availability. The update request and update response messages can be tunneled from the mobile terminal through the source network and the core network to the target network, rather than the messages being sent over-the-air from the target network to the mobile terminal.