Method and apparatus for handling radio link failure in wireless communication system

A User Equipment (UE) configured to handle a radio link failure (RLF) in a wireless communication system comprising a master cell group (MCG) and a secondary cell group (SCG) the UE comprising:

• a transceiver;
• and
• a processor coupled with the transceiver and configured to:
• receive a radio resource control (RRC) reconfiguration message including measurement configuration information for the SCG, via a signaling radio bearer 3 (SRB 3);
• identify that a measurement report type is set to event-triggered and a measurement report event for the SCG is triggered, based on report configuration information for the SCG including information indicating use of a T312 timer;
• in case that the information indicating the use of the T312 timer is included in the report configuration information for the SCG and a T310 timer is running, start the T312 timer based on the measurement configuration information for the SCG, including a value of the T312 timer;
• based on an expiry of the T312 timer on a primary SCG cell (PSCell), declare a RLF of the SCG;
• and
• transmit, via a signaling radio bearer 1 (SRB 1), a SCG failure message including a cause value corresponding to a failure type as the expiry of the T312 timer.