Method and apparatus for performing reconfiguration for cell level mobility in mobile wireless communication system

A terminal in a wireless communication system, the terminal comprising:

• a transceiver configured to transmit and receive a signal, and
• a controller configured to control the transceiver to:
• receive a first Radio Resource Control (RRC) reconfiguration message, wherein the first RRC reconfiguration message comprises information for a conditional reconfiguration to a first cell, wherein the information for the conditional reconfiguration to the first cell comprises a second RRC reconfiguration message;
• determine that execution condition of the conditional reconfiguration to the first cell is fulfilled;
• execute the conditional reconfiguration to the first cell based on the second RRC reconfiguration message;
• determine an uplink between a first uplink and a second uplink;
• and
• transmit based on the determination a RRC reconfiguration complete message in the first uplink or in the second uplink,
• wherein the uplink is determined based on a physical layer control information of the first cell in case that the second RRC reconfiguration message comprises a first set of parameters, and
• wherein the uplink is determined based on reception power of downlink pathloss reference of the first cell in case that the second RRC reconfiguration message does not comprise the first set of parameters.