Releasing Information to Improve Cell Selection in Different Resource Control States

Abstract

This document describes techniques and apparatuses for releasing information to improve cell selection in different resource control states. To improve communication performance, a user equipment (UE) 110 releases dedicated cell-selection information 306, which may not be appropriate as the UE 110 moves to different geographical locations and transitions to different resource control states 218. Different situations cause the UE 110 to release the dedicated cell-selection information 306, including performing a cell-selection procedure in an inactive state that selects another cell that does not support the inactive state, processing a paging message 308, or transitioning from the inactive state to an idle state. By releasing the dedicated cell-selection information 306, the UE 110 performs a future cell-selection procedure without relying on the dedicated cell-selection information. As a result, the UE 110 can select an optimal cell for achieving a target communication performance in different resource control states 218.

What is claimed is: 
     
         1 . A method performed by a user equipment, the method comprising:
 receiving, from a base station, IdleModeMobilityControlInfo for the user equipment to use for cell reselection;   storing the IdleModeMobilityControlInfo;   operating in an inactive state to suspend a connection to a current cell;   performing a cell-reselection procedure in the inactive state that selects another cell, the other cell associated with a core network that does not support the inactive state;   transitioning from the inactive state to an idle state to release the connection to the current cell; and   responsive to transitioning to the idle state, releasing the IdleModeMobilityControlInfo.   
     
     
         2 . The method of  claim 1 , wherein:
 the current cell comprises:
 a next-generation Node B cell; 
 a next-generation evolved Node B, ng-eNB, cell connected with a Fifth-Generation core network; or 
 an Evolved Universal Terrestrial Radio Access Node B cell connected with the Fifth-Generation core network; and 
   the other cell comprises:
 a Node B cell; 
 an evolved Node B cell connected with evolved packet core; 
 another ng-eNB cell connected with evolved packet core; 
 a Global System for Mobile Communication cell; or 
 a code-division multiple-access cell. 
   
     
     
         3 . The method of  claim 1 , wherein the receiving comprises receiving a request message that includes the IdleModeMobilityControlInfo. 
     
     
         4 . The method of  claim 3 , wherein:
 the request message further includes other IdleModeMobilityControlInfo; and   the method further comprises performing another cell-reselection procedure in the idle state using the other IdleModeMobilityControlInfo.   
     
     
         5 . The method of  claim 1 , further comprising:
 receiving a system information message that includes common cell-reselection information; and   performing another cell-reselection procedure in the idle state using the common cell-reselection information.   
     
     
         6 . The method of  claim 1 , wherein the receiving comprises receiving an RRCRelease message that includes the IdleModeMobilityControlInfo. 
     
     
         7 . The method of  claim 1 , wherein the IdleModeMobilityControlInfo comprises at least one of:
 priority information; or   a timer duration that specifies a time for releasing the IdleModeMobilityControlInfo.   
     
     
         8 . The method of  claim 7 , wherein:
 the IdleModeMobilityControlInfo comprises the timer duration; and   the releasing the IdleModeMobilityControlInfo comprises releasing the IdleModeMobilityControlInfo prior to or at the time specified by the timer duration.   
     
     
         9 . A user equipment comprising:
 a radio-frequency transceiver configured to:
 receive, from a base station, IdleModeMobilityControlInfo for the user equipment to use for cell reselection; and 
 perform a cell-reselection procedure in the inactive state that selects another cell, the other cell associated with a core network that does not support the inactive state; and 
   at least one processor configured to:
 store the IdleModeMobilityControlInfo; 
 operate in an inactive state to suspend a connection to a current cell; 
 responsive to the cell-reselection procedure, transition from the inactive state to an idle state to release the connection to the current cell; and 
 responsive to transitioning to the idle state, release the IdleModeMobilityControlInfo. 
   
     
     
         10 . The user equipment of  claim 9 , wherein the radio-frequency transceiver is further configured to receive a request message that includes the IdleModeMobilityControlInfo. 
     
     
         11 . The user equipment of  claim 9 , wherein the radio-frequency transceiver is further configured to receive an RRCRelease message that includes the IdleModeMobilityControlInfo. 
     
     
         12 . The user equipment of  claim 9 , wherein the IdleModeMobilityControlInfo comprises at least one of:
 priority information; or   a timer duration that specifies a time for releasing the IdleModeMobilityControlInfo.   
     
     
         13 . The user equipment of  claim 12 , wherein:
 the IdleModeMobilityControlInfo comprises the timer duration; and   the release of the IdleModeMobilityControlInfo occurs prior to or at the time specified by the timer duration.   
     
     
         14 . The user equipment of  claim 9 , wherein the radio-frequency transceiver is further configured to perform another cell-reselection procedure using other IdleModeMobilityControlInfo or common cell-reselection information. 
     
     
         15 . A method performed by a user equipment, the method comprising:
 receiving, from a base station, IdleModeMobilityControlInfo for the user equipment to use for cell reselection;   storing the IdleModeMobilityControlInfo;   operating in an inactive state to suspend a connection to a current cell;   performing a cell-reselection procedure in the inactive state that selects another cell, the other cell associated with a core network that does not support the inactive state;   responsive to the cell-reselection procedure, releasing the IdleModeMobilityControlInfo; and   transitioning from the inactive state to an idle state to release the connection to the current cell.   
     
     
         16 . The method of  claim 15 , further comprising performing an other cell-reselection procedure using other IdleModeMobilityControlInfo or common cell-reselection information. 
     
     
         17 . The method of  claim 16 , further comprising receiving a request message comprising the other IdleModeMobilityControlInfo, wherein the performing the other cell-reselection procedure comprises performing the cell-reselection procedure using the other IdleModeMobilityControlInfo. 
     
     
         18 . The method of  claim 16 , further comprising receiving an RRCRelease message comprising the other IdleModeMobilityControlInfo, wherein the performing the other cell-reselection procedure comprises performing the cell-reselection procedure using the other IdleModeMobilityControlInfo. 
     
     
         19 . The method of  claim 16 , further comprising receiving a system information message comprising the common cell-reselection information, wherein the performing the cell-reselection procedure comprises performing the cell-reselection procedure using the common cell-reselection information. 
     
     
         20 . The method of  claim 15 , wherein:
 the current cell comprises:
 a next-generation Node B cell; 
 a next-generation evolved Node B, ng-eNB, cell connected with a Fifth-Generation core network; or 
 an Evolved Universal Terrestrial Radio Access Node B cell connected with the Fifth-Generation core network; and 
   the other cell comprises:
 a Node B cell; 
 an evolved Node B cell connected with evolved packet core; 
 another ng-eNB cell connected with evolved packet core; 
 a Global System for Mobile Communication cell; or 
 a code-division multiple-access cell.