Method and apparatus for mobility management in wireless communication system

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

• a memory;
• a transceiver;
• and
• at least one processor operatively coupled to the memory and the transceiver, wherein the memory stores instructions that, based on being executed by the at least one processor, perform operations comprising:
• receiving, from a network, a configuration for conditional mobility, wherein the configuration for conditional mobility comprises a corresponding mobility condition for each of multiple candidate cells;
• evaluating mobility conditions for the multiple candidate cells based on the evaluation of a mobility condition for a target cell among the multiple candidate cells, starting a timer for a mobility attempt to the target cell;
• performing the mobility attempt to the target cell while the timer is running;
• and
• transmitting, to the network, report information based on a failure of the mobility attempt to the target cell, the failure of the mobility attempt to the target cell being related to an expiry of the timer,
• wherein the report information is transmitted based on an instruction received from the network,
• wherein the report information comprises candidate cell information for all of the multiple candidate cells based on the instruction, and
• wherein the report information comprises:
• a cell identity of the target cell that has failed the mobility attempt;
• a cell identity of at least one neighbor cell among the multiple candidate cells;
• and
• information informing that a mobility condition for the at least one neighbor cell has been fulfilled at a moment of the failure of the mobility attempt.

A non-transitory computer-readable medium having recorded thereon a program for performing each step of a method on a computer, the method comprising:

• receiving, from a network, a configuration for conditional mobility, wherein the configuration for conditional mobility comprises a corresponding mobility condition for each of multiple candidate cells;
• evaluating mobility conditions for the multiple candidate cells;
• based on the evaluation of a mobility condition for a target cell among the multiple candidate cells, starting a timer for a mobility attempt to the target cell;
• performing the mobility attempt to the target cell while the timer is running;
• and
• transmitting, to the network, report information based on a failure of the mobility attempt to the target cell, the failure of the mobility attempt to the target cell being related to an expiry of the timer,
• wherein the report information is transmitted based on an instruction received from the network,
• wherein the report information comprises candidate cell information for all of the multiple candidate cells based on the instruction, and
• wherein the report information comprises:
• a cell identity of the target cell that has failed the mobility attempt;
• a cell identity of at least one neighbor cell among the multiple candidate cells;
• and
• information informing that a mobility condition for the at least one neighbor cell has been fulfilled at a moment of the failure of the mobility attempt.