Method and apparatus for measuring frequency in wireless communication system

Abstract

A method, performed by a user equipment (UE), of performing measurement includes receiving measurement configuration information for measurement in an idle mode or an inactive mode from a base station, starting a timer based on the measurement configuration information, and performing measurement in the idle mode or the inactive mode while the timer running, wherein, when the timer expires in the idle mode or the inactive mode, the measurement configuration information is deleted.

What is claimed is: 
     
         1 . A method, performed by a user equipment (UE), of performing measurement, the method comprising:
 receiving measurement configuration information for measurement in an idle mode or an inactive mode from a base station;   starting a timer based on the measurement configuration information; and   performing measurement in the idle mode or the inactive mode while the timer is running,   wherein, when the timer expires in the idle mode or the inactive mode, the measurement configuration information is deleted.   
     
     
         2 . The method of  claim 1 , further comprising:
 transmitting a radio resource control (RRC) resume request message to the base station;   receiving a response message to the RRC resume request message; and   determining whether to keep performing measurement based on the response message.   
     
     
         3 . The method of  claim 2 , wherein the determining whether to keep performing measurement in the idle mode based on the response message comprises, when the response message is an RRC setup message or an RRC resume message, stopping the timer that is running and deleting the measurement configuration information. 
     
     
         4 . The method of  claim 2 , wherein the determining whether to keep performing measurement in the idle mode based on the response message comprises, when the response message is an RRC reject message, keeping performing measurement in the idle mode or the inactive mode. 
     
     
         5 . The method of  claim 1 , further comprising:
 receiving a UE information request message for requesting a measurement result;   transmitting a UE information response message comprising the measurement result; and   discarding the measurement result.   
     
     
         6 . The method of  claim 3 , further comprising maintaining configuration information of master cell group (MCG) Scell or secondary cell group (SCG),
 wherein the response message comprises information indicating whether to reconstruct the configuration information of the Scell or SCG, and   wherein the configuration information of the Scell or SCG is released or reconstructed based on the information indicating whether to reconstruct the configuration information of the Scell or SCG.   
     
     
         7 . The method of  claim 1 , further comprising:
 performing a cell reselection procedure; and   when a cell selected based on the cell reselection procedure is not a validity area, stopping the timer and discarding the measurement configuration information.   
     
     
         8 . The method of  claim 1 , further comprising:
 performing a cell reselection procedure; and   when a cell selected based on the cell reselection procedure is a cell using another radio access technology (RAT), stopping the timer that is running and discarding the measurement configuration information.   
     
     
         9 . The method of  claim 1 , further comprising, when the UE transitions from the inactive mode to the idle mode, maintaining the timer that is running and maintaining the measurement configuration information. 
     
     
         10 . The method of  claim 1 , further comprising, when the UE fails to find a cell to be camped on or fails to select a cell, not stopping the timer that is running or not deleting the measurement configuration information. 
     
     
         11 . A user equipment (UE) for performing measurement in an idle mode or an inactive mode, the UE comprising:
 a transceiver; and   a processor coupled with the transceiver and configured to receive measurement configuration information for measurement in the idle mode or the inactive mode from a base station, start a timer based on the measurement configuration information, perform measurement in the idle mode or the inactive mode while the timer runs, and remove the measurement configuration information when the timer expires in the idle mode or the inactive mode.   
     
     
         12 . The UE of  claim 11 , wherein the processor is further configured to transmit a radio resource control (RRC) resume request message to the base station, receive a response message to the RRC resume request message, and determine whether to keep performing measurement based on the response message. 
     
     
         13 . The UE of  claim 12 , wherein the processor is further configured to, when the response message is an RRC setup message or an RRC resume message, stop the timer that is running and discard the measurement configuration information. 
     
     
         14 . The UE of  claim 12 , wherein the processor is further configured to, when the response message is an RRC reject message, keep performing measurement in the idle mode or the inactive mode. 
     
     
         15 . The UE of  claim 11 , wherein the processor is further configured to receive a UE information request message for requesting a measurement result, transmit a UE information response message comprising the measurement result, and discard the measurement result. 
     
     
         16 . The UE of  claim 13 , wherein the processor is further configured to maintain master cell group (MCG) Scell or secondary cell group (SCG) configuration information,
 wherein the response message comprises information indicating whether to reconstruct the Scell or SCG configuration information, and   wherein the Scell or SCG configuration information is released or reconstructed based on the information indicating whether to reconstruct the Scell or SCG configuration information.   
     
     
         17 . The UE of  claim 11 , wherein the processor is further configured to:
 perform a cell reselection procedure; and   when a cell selected based on the cell reselection procedure is not a validity area, stop the timer and discard the measurement configuration information.   
     
     
         18 . The UE of  claim 11 , wherein the processor is further configured to:
 perform a cell reselection procedure; and   when a cell selected based on the cell reselection procedure is a cell using another radio access technology (RAT), stop the timer that is running and discard the measurement configuration information.   
     
     
         19 . The UE of  claim 11 , wherein the processor is further configured to, when the UE transitions from the inactive mode to the idle mode, maintain the timer that is running and maintain the measurement configuration information. 
     
     
         20 . The UE of  claim 11 , wherein the processor is further configured to, when the UE fails to find a cell to be camped on or fails to select a cell, not stop the timer that is running or not remove the measurement configuration information.