Method of handling call in handover in wireless communication system and wireless communication device using the same

A method of handling at least a call in handover in a wireless communication system, wherein the wireless communication system comprising at least a wireless communication network and a wireless communication device, the method comprising:

• receiving a message at a wireless communication device from the wireless communication network which transmits the massage to initiate a single radio voice call continuity (SRVCC) handover for switching at least a packet-switched (PS) call to at least a circuit-switched (CS) call;
• and
• setting, at the wireless communication device, a stream identifier of the CS call to an identifier value in response to receiving the message for initiating the SRVCC handover,
• wherein the wireless communication network further sets a stream identifier of the CS call to the identifier value in response to transmitting the message for initiating the SRVCC handover, and the wireless communication device is a user equipment (UE) with multicall capability of supporting simultaneously at least two CS calls, and
• wherein when the wireless communication device initiates another CS call after the SRVCC handover by sending a SETUP message to the wireless communication network, the wireless communication device sets a stream identifier of the another CS call in the SETUP message to a value different from the identifier value.