Carrier selection in a multi-carrier wireless network
A wireless device receives a downlink control information (DCI) on a primary cell. The DCI may comprise a field instructing a wireless device to activate a secondary cell. The wireless device activates the secondary cell in response to receiving the DCI.
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, from a base station, one or more messages comprising configuration parameters of a cell, wherein the configuration parameters comprise:
a first value for a first timer; and
a second value for a second timer, wherein the second timer is associated with monitoring a downlink control channel;
receive a medium-access control (MAC) control element (CE) indicating an activation of the cell;
based on the MAC CE:
activate the cell; and
start the first timer;
receive first downlink control information (DCI) indicating monitoring of the downlink control channel;
based on the first DCI:
start the second timer; and
monitor the downlink control channel; and
receive, while the first timer and the second timer are both running, second DCI comprising one or more of a downlink assignment or an uplink grant.
2. The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to restart, based on the receiving the second DCI, the second timer.
3. The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to:
stop the second timer; and
stop monitoring of the downlink control channel;
wherein stopping the second timer and stopping the monitoring of the downlink control channel are based on one or more of:
the first timer expiring; or
receiving a second MAC CE, wherein the second MAC CE indicates a deactivation of the cell.
4. The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to stop, based on the second timer expiring and while an activation status of the cell is maintained, monitoring of the downlink control channel.
5. The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to, based on the cell being active, perform at least one of:
measure one or more reference signals; or
monitor a second downlink control channel for receiving the first DCI.
6. The wireless device of claim 5 , wherein one of the one or more reference signals is a channel state information reference signal.
7. The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, cause the wireless device to measure one or more reference signals after activating the cell.
8. The wireless device of claim 1 , wherein the first timer is associated with physical layer deactivation.
9. The wireless device of claim 1 , wherein the second timer is associated with secondary cell deactivation.
10. 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, one or more messages comprising configuration parameters of a cell, wherein the configuration parameters comprise:
a first value for a first timer; and
a second value for a second timer, wherein the second timer is associated with the wireless device monitoring a downlink control channel;
transmit a medium-access control (MAC) control element (CE) indicating an activation of the cell;
based on the MAC CE:
activate the cell for the wireless device; and
start the first timer;
transmit first downlink control information (DCI) indicating monitoring of the downlink control channel;
based on the first DCI, start the second timer associated with the wireless device monitoring the downlink control channel; and
transmit, while the first timer and the second timer are both running, second DCI comprising one or more of a downlink assignment or an uplink grant.
11. The base station of claim 10 , wherein the instructions, when executed by the one or more processors, further cause the base station to, based on the second DCI, restart the second timer.
12. The base station of claim 10 , wherein the instructions, when executed by the one or more processors, further cause the base station to stop the second timer based on one or more of:
the first timer expiring; or
transmitting a second MAC CE indicating deactivation of the cell.
13. The base station of claim 10 , wherein the first timer is associated with physical layer deactivation.
14. The base station of claim 10 , wherein the second timer is associated with secondary cell deactivation.
15. A non-transitory computer-readable medium storing instructions that, when executed, configure a wireless device to:
receive, from a base station, one or more messages comprising configuration parameters of a cell, wherein the configuration parameters comprise:
a first value for a first timer; and
a second value for a second timer, wherein the second timer is associated with monitoring a downlink control channel;
receive a medium-access control (MAC) control element (CE) indicating an activation of the cell;
based on the MAC CE:
activate the cell; and
start the first timer;
receive first downlink control information (DCI) indicating monitoring of the downlink control channel;
based on the first DCI:
start the second timer; and
monitor the downlink control channel; and
receive, while the first timer and the second timer are both running, second DCI comprising one or more of a downlink assignment or an uplink grant.
16. The non-transitory computer-readable medium of claim 15 , wherein the instructions, when executed, configure the wireless device to restart, based on the receiving the second DCI, the second timer.
17. The non-transitory computer-readable medium of claim 15 , wherein the instructions, when executed, configure the wireless device to:
stop the second timer; and
stop monitoring of the downlink control channel;
wherein stopping the second timer and stopping monitoring of the downlink control channel are based on one or more of:
the first timer expiring; or
receiving a second MAC CE, wherein the second MAC CE indicates a deactivation of the cell.
18. The non-transitory computer-readable medium of claim 15 , wherein the instructions, when executed, configure the wireless device to stop, based on the second timer expiring and while an activation status of the cell is maintained, monitoring of the downlink control channel.
19. The non-transitory computer-readable medium of claim 15 , wherein the instructions, when executed, configure the wireless device to, based on the cell being active, perform at least one of:
measure one or more reference signals; or
monitor a second downlink control channel for receiving the first DCI.
20. The non-transitory computer-readable medium of claim 19 , wherein one of the one or more reference signals is a channel state information reference signal.
21. The non-transitory computer-readable medium of claim 15 , wherein the instructions, when executed, configure the wireless device to measure one or more reference signals after activating the cell.
22. The non-transitory computer-readable medium of claim 15 , wherein the first timer is associated with physical layer deactivation.
23. The non-transitory computer-readable medium of claim 15 , wherein the second timer is associated with secondary cell deactivation.
24. A non-transitory computer-readable medium storing instructions that, when executed, configure a base station to:
transmit, to a wireless device, one or more messages comprising configuration parameters of a cell, wherein the configuration parameters comprise:
a first value for a first timer; and
a second value for a second timer, wherein the second timer is associated with the wireless device monitoring a downlink control channel;
transmit a medium-access control (MAC) control element (CE) indicating an activation of the cell;
based on the MAC CE:
activate the cell for the wireless device; and
start the first timer;
transmit first downlink control information (DCI) indicating monitoring of the downlink control channel;
based on the first DCI, start the second timer associated with the wireless device monitoring the downlink control channel; and
transmit, while the first timer and the second timer are both running, second DCI comprising one or more of a downlink assignment or an uplink grant.
25. The non-transitory computer-readable medium of claim 24 , wherein the instructions, when executed, configure the base station to, based on the second DCI, restart the second timer.
26. The non-transitory computer-readable medium of claim 24 , wherein the instructions, when executed, configure the base station to stop the second timer based on one or more of:
the first timer expiring; or
transmitting a second MAC CE indicating deactivation of the cell.
27. The non-transitory computer-readable medium of claim 24 , wherein the first timer is associated with physical layer deactivation.
28. The non-transitory computer-readable medium of claim 24 , wherein the second timer is associated with secondary cell deactivation.
29. A system comprising:
a base station configured to:
send one or more messages comprising configuration parameters of a cell, wherein the configuration parameters comprise:
a first value for a first timer; and
a second value for a second timer, wherein the second timer is associated with monitoring a downlink control channel; and
a wireless device configured to:
receive, from the base station, the one or more messages comprising the configuration parameters;
receive a medium-access control (MAC) control element (CE) indicating an activation of the cell;
based on the MAC CE:
activate the cell; and
start the first timer;
receive first downlink control information (DCI) indicating monitoring of the downlink control channel
based on the first DCI:
start the second timer; and
monitor the downlink control channel; and
receive, while the first timer and the second timer are both running, second DCI comprising one or more of a downlink assignment or an uplink grant.
30. The system of claim 29 , wherein the wireless device is further configured to restart, based on the receiving the second DCI, the second timer.
31. The system of claim 29 , wherein the wireless device is further configured to:
stop the second timer; and
stop monitoring of the downlink control channel;
wherein stopping the second timer and stopping the monitoring of the downlink control channel are based on one or more of:
the first timer expiring; or
receiving a second MAC CE, wherein the second MAC CE indicates a deactivation of the cell.
32. The system of claim 29 , wherein the wireless device is further configured to stop, based on the second timer expiring and while an activation status of the cell is maintained, monitoring of the downlink control channel.
33. The system of claim 29 , wherein the wireless device is further configured to, based on the cell being active, perform at least one of:
measure one or more reference signals; or
monitor a second downlink control channel for receiving the first DCI.
34. The system of claim 33 , wherein one of the one or more reference signals is a channel state information reference signal.
35. The system of claim 29 , wherein the wireless device is further configured to measure one or more reference signals after activating the cell.
36. The system of claim 29 , wherein the first timer is associated with physical layer deactivation.
37. The system of claim 29 , wherein the second timer is associated with secondary cell deactivation.