Handover apparatus and method in a heterogeneous wireless communication system

A call manager for providing a handover of a session between a User Equipment (UE) in a Long Term Evolution (LTE) network and another UE to a session between the UE in a Circuit Switching (CS) network and the another UE in a wireless communication system, the call manager comprising:

• a first interface for receiving, from an Enhanced Node B (ENB) of the LTE network, a handover required message for a Packet Switching (PS) to CS handover from the LTE network to the CS network, when the PS to CS handover is decided based on measurement reports of the UE;
• a second interface for sending, to a Mobile Switching Center (MSC) of the CS network, a PS to CS handover request message including an International Mobile Subscriber Identity (IMSI) for identifying the UE and a target identifier (ID) for a target cell of the CS network, and receiving a PS to CS handover response message from the MSC;
• and
• a controller for sending, to the UE via the ENB, a handover command message by controlling the first interface,
• wherein the call manager communicates with the LTE network and the CS network.