Cell activation and deactivation in a wireless network

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 one or more radio resource control (RRC) messages configuring:

a first medium access control (MAC) cell deactivation timer for MAC activating a cell; and

a second deactivation timer associated with monitoring a physical downlink control channel for the cell;

receive a MAC control element (CE) indicating MAC activating the cell;

in response to receiving the MAC CE, MAC activate the cell and start the MAC cell deactivation timer;

receive a first downlink control information (DCI) comprising a field indicating activation to monitor the physical downlink control channel;

based on receiving the first DCI:

start monitoring the physical downlink control channel;

start the MAC cell deactivation timer; and

start the second deactivation timer;

receive a second DCI comprising a field indicating not monitoring the physical downlink control channel; and

based on the second DCI, stop monitoring the physical downlink control channel, wherein the cell is maintained as MAC activated.

2 . The wireless device of claim 1 , wherein the instructions, when executed by the one or more processors, further cause the wireless device, when the first MAC cell deactivation timer expires or the wireless device receives a MAC deactivation command for the cell, to:

stop the second deactivation timer;

stop the first MAC cell deactivation timer;

MAC deactivate the cell; and

stop monitoring the physical downlink control channel.

3 . The wireless device of claim 2 , wherein the instructions, when executed by the one or more processors, further cause the wireless device, when the second deactivation timer expires, to:

stop monitoring the physical downlink control channel;

maintain the cell as MAC activated; and

start monitoring a search space for receiving an indication to monitor the physical downlink control channel.

4 . The wireless device of claim 3 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to monitor the physical downlink control channel when the first MAC cell deactivation timer and the second deactivation timer are running.

5 . The wireless device of claim 3 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to start monitoring a second physical downlink control channel based on the second DCI.

6 . The wireless device of claim 3 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to:

receive a third DCI indicating an uplink grant or downlink assignment for the cell; and

based on the third DCI:

start the first MAC cell deactivation timer;

start the second deactivation timer; and

start monitoring the physical downlink control channel.

7 . The wireless device of claim 1 , wherein the second deactivation timer is associated with PHY activation and PHY deactivation, and wherein:

the PHY activation comprises monitoring the physical downlink control channel; and

the PHY deactivation comprises not monitoring the physical downlink control channel.

8 . The wireless device of claim 7 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to:

receive a third DCI indicating an uplink grant or downlink assignment for the cell; and

based on the third DCI:

start the first MAC cell deactivation timer;

start the second deactivation timer; and

start monitoring the physical downlink control channel.

9 . The wireless device of claim 8 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to, based on the second DCI, switch to monitor another physical downlink control channel.

10 . The wireless device of claim 9 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to stop monitoring the physical downlink control channel, based on the second deactivation timer expiring.

11 . The wireless device of claim 10 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to stop the second deactivation timer in response to receiving the second DCI.

12 . The wireless device of claim 7 , wherein the instructions, when executed by the one or more processors, further cause the wireless device, when the second deactivation timer expires, to:

stop monitoring the physical downlink control channel;

maintain the cell as MAC activated; and

start monitoring a search space for receiving an indication to monitor the physical downlink control channel.

13 . The wireless device of claim 12 , wherein the instructions, when executed by the one or more processors, further cause the wireless device, when the first MAC cell deactivation timer expires or the wireless device receives a MAC deactivation command for the cell, to:

stop the second deactivation timer;

stop the first MAC cell deactivation timer;

MAC deactivate the cell; and

stop monitoring the physical downlink control channel.

14 . A method performed by a wireless device, the method comprising:

receiving one or more radio resource control (RRC) messages configuring:

a first medium access control (MAC) cell deactivation timer for MAC activating a cell; and

a second deactivation timer associated with monitoring a physical downlink control channel for the cell;

receiving a MAC control element (CE) indicating MAC activating the cell;

in response to receiving the MAC CE, MAC activating the cell and starting the MAC cell deactivation timer;

receiving a first downlink control information (DCI) comprising a field indicating activation to monitor the physical downlink control channel;

based on receiving the first DCI:

starting monitoring the physical downlink control channel;

starting the MAC cell deactivation timer; and

starting the second deactivation timer;

receiving a second DCI comprising a field indicating not monitoring the physical downlink control channel; and

based on the second DCI, stopping monitoring the physical downlink control channel, wherein the cell is maintained as MAC activated.

15 . The method of claim 14 , further comprising, when the first MAC cell deactivation timer expires or the wireless device receives a MAC deactivation command for the cell:

stopping the second deactivation timer;

stopping the first MAC cell deactivation timer;

MAC deactivating the cell; and

stopping monitoring the physical downlink control channel.

16 . The method of claim 15 , further comprising, when the second deactivation timer expires:

stopping monitoring the physical downlink control channel;

maintaining the cell as MAC activated; and

starting monitoring a search space for receiving an indication to monitor the physical downlink control channel.

17 . The method of claim 16 , further comprising monitoring the physical downlink control channel when the first MAC cell deactivation timer and the second deactivation timer are running.

18 . The method of claim 16 , further comprising starting monitoring a second physical downlink control channel based on the second DCI.

19 . The method of claim 16 , further comprising:

receiving a third DCI indicating an uplink grant or downlink assignment for the cell; and

based on the third DCI:

starting the first MAC cell deactivation timer;

starting the second deactivation timer; and

starting monitoring the physical downlink control channel.

20 . The method of claim 14 , wherein the second deactivation timer is associated with PHY activation and PHY deactivation, and wherein:

the PHY activation comprises monitoring the physical downlink control channel; and

the PHY deactivation comprises not monitoring the physical downlink control channel.

21 . The method of claim 20 , further comprising:

receiving a third DCI indicating an uplink grant or downlink assignment for the cell; and

based on the third DCI:

starting the first MAC cell deactivation timer;

starting the second deactivation timer; and

starting monitoring the physical downlink control channel.

22 . The method of claim 21 , further comprising, based on the second DCI, switching to monitor another physical downlink control channel.

23 . The method of claim 22 , further comprising stopping monitoring the physical downlink control channel, based on the second deactivation timer expiring.

24 . The method of claim 23 , further comprising stopping the second deactivation timer in response to receiving the second DCI.

25 . The method of claim 20 , further comprising, when the second deactivation timer expires:

stopping monitoring the physical downlink control channel;

maintaining the cell as MAC activated; and

starting monitoring a search space for receiving an indication to monitor the physical downlink control channel.

26 . The method of claim 25 , further comprising, when the first MAC cell deactivation timer expires or the wireless device receives a MAC deactivation command for the cell:

stopping the second deactivation timer;

stopping the first MAC cell deactivation timer;

MAC deactivating the cell; and

stopping monitoring the physical downlink control channel.