Power Saving for Downlink Control Channel Monitoring of Secondary Cells

Abstract

A wireless device receives a medium access control control element (MAC CE) indicating activation of one or more secondary cells (SCells) of a plurality of SCells. A first downlink control channel of a first SCell of the one or more SCells is monitored. A downlink control information including a bitmap for power saving indication is received. Each bit of the bitmap corresponds to an SCell, of the plurality of SCells, in an ascending order of SCell indexes. A value of each bit indicates whether to monitor a downlink control channel on the corresponding SCell. Monitoring of the first downlink control channel is stopped, with the first SCell maintained as activated, in response to a bit, of the bitmap, corresponding to the first SCell and indicating not to monitor the first downlink control channel.

What is claimed is: 
     
         1 . A wireless device comprising:
 one or more processors; and   memory storing instructions that, when executed by the one or more processors, cause the wireless device to:
 receive a medium access control control element (MAC CE) indicating activation of one or more secondary cells (SCells) of a plurality of SCells; 
 monitor a first downlink control channel of a first SCell of the one or more SCells; 
 receive a downlink control information (DCI) comprising a bitmap for power saving indication, wherein:
 each bit of the bitmap corresponds to an SCell, of the plurality of SCells, in an ascending order of SCell indexes; and 
 a value of each bit indicates whether to monitor a downlink control channel on the corresponding SCell; and 
 
 stop monitoring the first downlink control channel, with the first SCell maintained as activated, in response to a bit, of the bitmap, corresponding to the first SCell and indicating not to monitor the first downlink control channel. 
   
     
     
         2 . The wireless device of  claim 1 , wherein to monitor the first downlink control channel, the instructions further cause the wireless device to monitor the first downlink control channel on a first downlink bandwidth part of the first SCell. 
     
     
         3 . The wireless device of  claim 1 , wherein the bit indicates whether to monitor the downlink control channel of a downlink bandwidth part of the corresponding SCell. 
     
     
         4 . The wireless device of  claim 1 , wherein the monitoring of the first downlink control channel is stopped on a downlink bandwidth part of the first SCell. 
     
     
         5 . The wireless device of  claim 1 , wherein the instructions further cause the wireless device to activate a bandwidth part of each of the one or more SCells before the receiving the first DCI. 
     
     
         6 . The wireless device of  claim 1 , wherein the plurality of SCells comprise a plurality of deactivated SCells. 
     
     
         7 . The wireless device of  claim 1 , wherein the first downlink control channel is monitored discontinuously in response to a discontinuous reception operation being configured on the first SCell. 
     
     
         8 . The wireless device of  claim 1 , wherein the first SCell maintained as activated comprises performing channel state information measurement on a first downlink bandwidth part of the first SCell. 
     
     
         9 . The wireless device of  claim 1 , wherein the first SCell maintained as activated comprises keeping running a SCell deactivation timer associated with the first SCell. 
     
     
         10 . The wireless device of  claim 1 , wherein the first DCI is received via a primary cell. 
     
     
         11 . A base station comprising:
 one or more processors; and   memory storing instructions that, when executed by the one or more processors, cause the base station to:
 transmit, to a wireless device, a medium access control control element (MAC CE) indicating activation of one or more secondary cells (SCells) of a plurality of SCells; 
 transmitting, to the wireless device, a first downlink control channel of a first SCell of the one or more activated SCells; 
 transmit, to the wireless device, a downlink control information (DCI) comprising a bitmap for power saving indication, wherein:
 each bit of the bitmap corresponds to an SCell, of the plurality of SCells, in an ascending order of SCell indexes; and 
 a value of each bit indicates whether the wireless device monitors a downlink control channel on the corresponding SCell; and 
 
 stop transmitting, to the wireless device, the first downlink control channel of the first SCell, with the first SCell maintained as activated, for the wireless device in response to a bit, of the bitmap, corresponding to the first SCell and indicating not to monitor the first downlink control channel. 
   
     
     
         12 . The base station of  claim 11 , wherein to transmit the first downlink control channel, the instructions further cause the base station to transmit the first downlink control channel on a first downlink bandwidth part of the first SCell. 
     
     
         13 . The base station of  claim 11 , wherein the bit indicates whether the wireless device monitors the downlink control channel of a downlink bandwidth part of the corresponding SCell. 
     
     
         14 . The base station of  claim 11 , wherein the transmission of the first downlink control channel is stopped on a downlink bandwidth part of the first SCell. 
     
     
         15 . The base station of  claim 11 , wherein the instructions further cause the base station to activate, for the wireless device, a bandwidth part of each of the one or more SCells before the transmitting the first DCI. 
     
     
         16 . The base station of  claim 11 , wherein the plurality of SCells comprise a plurality of deactivated SCells. 
     
     
         17 . The base station of  claim 11 , wherein the first downlink control channel is transmitted discontinuously in response to a discontinuous reception operation being configured on the first SCell. 
     
     
         18 . The base station of  claim 11 , wherein the first SCell maintained as activated comprises receiving channel state information measurement on a first downlink bandwidth part of the first SCell. 
     
     
         19 . The base station of  claim 11 , wherein the first SCell maintained as activated comprises keeping running, for the wireless device, a SCell deactivation timer associated with the first SCell. 
     
     
         20 . A system comprising:
 a base station comprising one or more first processors and first memory storing first instructions that, when executed by the one or more first processors, cause the base station to:
 transmit a medium access control control element (MAC CE) indicating activation of one or more secondary cells (SCells) of a plurality of SCells; and 
 transmit a downlink control information (DCI) comprising a bitmap for power saving indication, wherein:
 each bit of the bitmap corresponds to an SCell, of the plurality of SCells, in an ascending order of SCell indexes; and 
 a value of each bit indicates whether to monitor a downlink control channel on the corresponding SCell; and 
 
   a wireless device comprising one or more second processors and second memory storing second instructions that, when executed by the one or more second processors, cause the wireless device to:
 receive the MAC CE indicating the activation of the one or more SCells; 
 monitor a first downlink control channel of a first SCell of the one or more SCells; 
 receive the DCI comprising the bitmap for power saving indication; and 
 stop monitoring the first downlink control channel, with the first SCell maintained as activated, in response to a bit, of the bitmap, corresponding to the first SCell and indicating not to monitor the first downlink control channel.