Scheduling wireless communications

1. A method comprising:

monitoring, by a wireless device, for first downlink control information (DCI) indicating resources of a primary cell, a common search space of the primary cell;

monitoring, for second DCI indicating resources of the primary cell, a first wireless device-specific search space of the primary cell; and

based on cross-carrier scheduling of the primary cell:

continuing monitoring, for the first DCI, the common search space of the primary cell;

stopping monitoring, for the second DCI, the first wireless device-specific search space of the primary cell; and

starting monitoring, for third DCI indicating resources of the primary cell, a second wireless device-specific search space of a secondary cell.

2. The method of claim 1 , further comprising, receiving one or more messages comprising configuration parameters for the primary cell, wherein the configuration parameters indicate:

the common search space of the primary cell;

the first wireless device-specific search space of the primary cell; and

the second wireless device-specific search space, of the secondary cell, for cross-carrier scheduling of the primary cell.

3. The method of claim 1 , further comprising:

receiving, via the second wireless device-specific search space of the secondary cell, DCI indicating first resources of the primary cell; and

communicating, based on the receiving the DCI indicating first resources of the primary cell, via the first resources of the primary cell.

4. The method of claim 1 , further comprising:

receiving, via the common search space of the primary cell, DCI indicating first resources of the primary cell; and

communicating, based on the receiving the DCI indicating first resources of the primary cell, via the first resources of the primary cell.

5. The method of claim 1 , wherein:

the first DCI is based on one or more first DCI formats;

the second DCI is based on one or more second DCI formats; and

the third DCI is based on the one or more second DCI formats.

6. The method of claim 1 , further comprising receiving one or more radio resource control (RRC) messages indicating a cell indicator of the secondary cell.

7. The method of claim 1 , further comprising enabling cross-carrier scheduling of the primary cell based on receiving at least one of:

a radio resource control (RRC) message;

a medium access control control element (MAC CE); or

DCI.

8. The method of claim 1 , wherein the starting monitoring the second wireless device-specific search space of the secondary cell comprises starting monitoring the second wireless device-specific search space of the secondary cell based on enabling cross-carrier scheduling of the primary cell.

9. The method of claim 1 , wherein:

the first DCI comprises cyclic redundancy check (CRC) bits scrambled with one of one or more first radio network temporary identifier (RNTIs);

the second DCI comprises CRC bits scrambled with one of one or more second RNTIs; and

the third DCI comprises CRC bits scrambled with the one of one or more second RNTIs.

10. A method comprising:

receiving, by a wireless device, one or more first message comprising configuration parameters for a primary cell, wherein the configuration parameters indicate:

a common search space of the primary cell; and

a first wireless device-specific search space of the primary cell;

based on the receiving the one or more first messages:

monitoring, for first downlink control information (DCI) indicating resources of the primary cell, the common search space of the primary cell; and

monitoring, for second DCI indicating resources of the primary cell, the first wireless device-specific search space of the primary cell;

receiving one or more second messages indicating a second wireless device-specific search space, of a secondary cell, for cross-carrier scheduling of the primary cell; and

based on the receiving the one or more second messages:

continuing monitoring, for the first DCI, the common search space of the primary cell; and

starting monitoring, for third DCI indicating resources of the primary cell, the second wireless device-specific search space of the secondary cell.

11. The method of claim 10 , further comprising, based on receiving the one or more second messages, stopping monitoring, for the second DCI, the first wireless device-specific search space of the primary cell.

12. The method of claim 10 , further comprising:

receiving, via the second wireless device-specific search space of the secondary cell, DCI indicating first resources of the primary cell; and

communicating, based on the receiving the DCI indicating first resources of the primary cell, via the first resources of the primary cell.

13. The method of claim 10 , further comprising:

receiving, via the common search space of the primary cell, DCI indicating first resources of the primary cell; and

communicating, based on the receiving the DCI indicating first resources of the primary cell, via the first resources of the primary cell.

14. The method of claim 10 , further comprising enabling cross-carrier scheduling of the primary cell based on receiving at least one of:

the one or more second messages;

a radio resource control (RRC) message;

a medium access control control element (MAC CE); or

DCI.

15. The method of claim 10 , wherein the one or more second messages indicate a cell indicator of the secondary cell.

16. A method comprising:

receiving, by a wireless device, one or more messages comprising configuration parameters for a primary cell, wherein the configuration parameters indicate:

a common search space of the primary cell; and

a wireless device-specific search space, of a secondary cell, for cross-carrier scheduling of the primary cell; and

based on the receiving the one or more messages:

monitoring, based on a first DCI format and for first downlink control information (DCI) indicating resources of the primary cell, the common search space of the primary cell; and

monitoring, based on a second DCI format and for second DCI indicating resources of the primary cell, the wireless device-specific search space of the secondary cell, wherein the second DCI format is different from the first DCI format.

17. The method of claim 16 , wherein the configuration parameters further indicate a second wireless device-specific search space of the primary cell, and wherein the method further comprises:

receiving a command indicating deactivation of cross-carrier scheduling of the primary cell; and

based on the receiving the command:

stopping monitoring, for the second DCI, the wireless device-specific search space of the secondary cell; and

starting monitoring, for third DCI based on the second DCI format, the second wireless device-specific search space of the primary cell.

18. The method of claim 16 , further comprising:

receiving, via the wireless device-specific search space of the secondary cell, DCI indicating first resources of the primary cell; and

communicating, based on the receiving the DCI indicating the first resources of the primary cell, via the first resources of the primary cell.

19. The method of claim 16 , further comprising:

receiving, via the common search space of the primary cell, DCI indicating first resources of the primary cell; and

communicating, based on the receiving the DCI indicating first resources of the primary cell, via the first resources of the primary cell.

20. The method of claim 16 , further comprising enabling cross-carrier scheduling of the primary cell based on the receiving the one or more messages, wherein the monitoring the wireless device-specific search space of the secondary cell comprises monitoring the wireless device-specific search space of the secondary cell based on the enabling cross-carrier scheduling of the primary cell.