Method and apparatus for terminal in RRC_inactive to perform extended DRX operation in mobile wireless communication system

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

• a transceiver configured to transmit and receive signals;
• and
• a controller configured to control the transceiver to:
• receive, from an Access and Mobility Management Function (AMF), a first message including a first discontinuous reception cycle and a second discontinuous reception cycle;
• receive, from a base station, a second message including a third discontinuous reception cycle;
• receive a system information in a first cell;
• determine a reference paging cycle;
• determine a paging frame based on the reference paging cycle;
• monitor a paging occasion in the paging frame;
• receive a paging message based on the paging occasion in the paging frame;
• and
• discard the third discontinuous reception cycle in case that the paging message comprises a specific identity of the terminal,
• wherein the reference paging cycle is determined based on the second discontinuous reception cycle and a fourth discontinuous reception cycle in case that:
• a first information related to extended discontinuous reception is included in the system information;
• and
• the second message includes the third discontinuous reception cycle and the fourth discontinuous reception cycle, and
• wherein the reference paging cycle is determined based on the second discontinuous reception cycle and the third discontinuous reception cycle in case that:
• the first information related to extended discontinuous reception is included in the system information;
• and
• the second message does not include the fourth discontinuous reception cycle.