A method of performing, by a user equipment, UE, a Minimization Drive Test, MDT, in a wireless communication system, the method comprising: receiving a logged measurement configuration; performing MDT measurement and logging a measurement result based on the logged measurement configuration, wherein the logged measurement configuration comprises logging start time information indicative of a start time when performing the MDT measurement and logging the measurement result are allowed, wherein the logged measurement configuration comprises logging end time information indicating that the MDT measurement and the measurement result logging are ended, wherein the MDT measurement and logging the measurement result are performed when the start time indicated by the logging start time information is reached and until the end time indicated by the logging end time information, wherein the logged measurement configuration comprises logging interval information, the logging interval information indicates a specific time interval, and wherein the step of performing the MDT measurement and logging the measurement result are periodically performed in accordance with the specific time interval, wherein the specific time interval is set by a network; discarding the logged measurement configuration and initiating a conservation timer when the end time indicated by the logging end time information elapses; and discarding the logged measurement when the conservation timer expires, wherein the conservation timer is expired at 48 hours after discarding the logged measurement configuration, characterized in that the logged measurement configuration comprises log report start time information, the log report start time information indicating a start time when the report is allowed, and that the logged measurement configuration further comprises log report end time information, the log report end time information indicating an end time when the report is ended, wherein the report is performed when the start time indicated by the log report start time is reached and until the end time indicated by the log report end time, wherein the method further comprises discarding remaining logged measurement result if the end time indicated by the log report end time information elapses. receiving a logged measurement configuration; performing MDT measurement and logging a measurement result based on the logged measurement configuration, wherein the logged measurement configuration comprises logging start time information indicative of a start time when performing the MDT measurement and logging the measurement result are allowed, wherein the logged measurement configuration comprises logging end time information indicating that the MDT measurement and the measurement result logging are ended, wherein the MDT measurement and logging the measurement result are performed when the start time indicated by the logging start time information is reached and until the end time indicated by the logging end time information, wherein the logged measurement configuration comprises logging interval information, the logging interval information indicates a specific time interval, and wherein the step of performing the MDT measurement and logging the measurement result are periodically performed in accordance with the specific time interval, wherein the specific time interval is set by a network; discarding the logged measurement configuration and initiating a conservation timer when the end time indicated by the logging end time information elapses; and discarding the logged measurement when the conservation timer expires, wherein the conservation timer is expired at 48 hours after discarding the logged measurement configuration, characterized in that the logged measurement configuration comprises log report start time information, the log report start time information indicating a start time when the report is allowed, and that the logged measurement configuration further comprises log report end time information, the log report end time information indicating an end time when the report is ended, wherein the report is performed when the start time indicated by the log report start time is reached and until the end time indicated by the log report end time, wherein the method further comprises discarding remaining logged measurement result if the end time indicated by the log report end time information elapses.