Method and apparatus for improving a mobility in a telecommunication network

A method performed by a base station in a wireless communication system, the method comprising:

• transmitting, to a user equipment (UE), a radio resource control (RRC) reconfiguration message including layer 1/layer 2 (L1/L2) triggered mobility (LTM) configuration information,
• receiving, from the UE, a first RRC reconfiguration complete message, as a response to the RRC reconfiguration message;
• and
• transmitting, to the UE, a medium access control (MAC) control element (CE) to trigger an LTM cell switch procedure to a target cell,
• wherein the LTM cell switch procedure is performed based on the MAC CE, and
• wherein the LTM cell switch procedure is completed, based on a second RRC reconfiguration complete message transmitted from the UE to the target cell.

A user equipment (UE) in a wireless communication system, the UE comprising:

• a transceiver;
• and
• a controller configured to:
• control the transceiver to receive, from a base station, a radio resource control (RRC) reconfiguration message including layer 1/layer 2 (L1/L2) triggered mobility (LTM) configuration information,
• control the transceiver to transmit, to the base station, a first RRC reconfiguration complete message, as a response to the RRC reconfiguration message,
• control the transceiver to receive, from the base station, a medium access control (MAC) control element (CE) to trigger an LTM cell switch procedure to a target cell,
• perform the LTM cell switch procedure based on the MAC CE, and
• control the transceiver to transmit, to the target cell, a second RRC reconfiguration complete message for a completion of the LTM cell switch procedure.

A base station in a wireless communication system, the base station comprising:

• a transceiver;
• and
• a controller configured to:
• control the transceiver to transmit, to a user equipment (UE), a radio resource control (RRC) reconfiguration message including layer 1/layer 2 (L1/L2) triggered mobility (LTM) configuration information,
• control the transceiver to receive, from the UE, a first RRC reconfiguration complete message, as a response to the RRC reconfiguration message, and
• control the transceiver to transmit, to the UE, a medium access control (MAC) control element (CE) to trigger an LTM cell switch procedure to a target cell,
• wherein the LTM cell switch procedure is performed based on the MAC CE, and
• wherein the LTM cell switch procedure is completed, based on a second RRC reconfiguration complete message transmitted from the UE to the target cell.