Cell timing in a wireless device and base station
Methods, apparatuses, and systems are described for wireless communications. A transmission timing difference between a first cell group and a second cell group may be determined. If the transmission timing difference exceeds a threshold, one or more devices may stop transmitting uplink signals via one or more secondary cells and/or may not apply the timing adjustment for a cell group.
1. A method comprising:
performing, by a wireless device and using a first timing advance, a first uplink transmission via one or more secondary cells associated with a first cell group;
based on a transmission timing difference between the first cell group and a second cell group exceeding a threshold, stopping at least one uplink transmission for the one or more secondary cells; and
after the stopping the at least one uplink transmission for the one or more secondary cells, performing, using a second timing advance, a second uplink transmission via the one or more secondary cells.
2. The method of claim 1 , further comprising determining that the one or more secondary cells are out-of-sync, wherein the performing the second uplink transmission comprises performing the second uplink transmission during a time that the one or more secondary cells are out-of-sync.
3. The method of claim 1 , further comprising:
based on the transmission timing difference exceeding the threshold, determining that a time alignment timer is expired,
wherein the performing the second uplink transmission comprises performing the second uplink transmission during a time that the time alignment timer is not running.
4. The method of claim 1 , wherein the transmission timing difference comprises a difference between:
uplink transmission timing associated with the first cell group; and
uplink transmission timing associated with the second cell group.
5. The method of claim 1 , wherein the transmission timing difference comprises a difference between:
a timing of a first synchronization signal; and
a timing of a second synchronization signal.
6. The method of claim 1 , wherein the first timing advance is a non-zero timing advance and the second timing advance is a zero timing advance.
7. The method of claim 1 , further comprising:
receiving a first timing advance command, wherein the first timing advance is based on the first timing advance command;
receiving a second timing advance command; and
determining, based on the second timing advance command, the transmission timing difference.
8. The method of claim 1 , wherein the second uplink transmission comprises a random access preamble.
9. A wireless device comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause a wireless device to:
perform, using a first timing advance, a first uplink transmission via one or more secondary cells associated with a first cell group;
based on a transmission timing difference between the first cell group and a second cell group exceeding a threshold, stop at least one uplink transmission for the one or more secondary cells; and
after stopping the at least one uplink transmission for the one or more secondary cells, perform, using a second timing advance, a second uplink transmission via the one or more secondary cells.
10. The wireless device of claim 9 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to determine that the one or more secondary cells are out-of-sync, and to perform the second uplink transmission during a time that the one or more secondary cells are out-of-sync.
11. The wireless device of claim 9 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to:
based on the transmission timing difference exceeding the threshold, determine that a time alignment timer is expired; and
perform the second uplink transmission during a time that the time alignment timer is not running.
12. The wireless device of claim 9 , wherein the transmission timing difference comprises a difference between:
uplink transmission timing associated with the first cell group; and
uplink transmission timing associated with the second cell group.
13. The wireless device of claim 9 , wherein the transmission timing difference comprises a difference between:
a timing of a first synchronization signal; and
a timing of a second synchronization signal.
14. The wireless device of claim 9 , wherein the first timing advance is a non-zero timing advance and the second timing advance is a zero timing advance.
15. The wireless device of claim 9 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to:
receive a first timing advance command, wherein the first timing advance is based on the first timing advance command;
receive a second timing advance command; and
determine, based on the second timing advance command, the transmission timing difference.
16. The wireless device of claim 9 , wherein the second uplink transmission comprises a random access preamble.
17. A non-transitory computer-readable medium storing instructions that, when executed, configure a wireless device to:
perform, using a first timing advance, a first uplink transmission via one or more secondary cells associated with a first cell group;
based on a transmission timing difference between the first cell group and a second cell group exceeding a threshold, stop at least one uplink transmission for the one or more secondary cells; and
after stopping the at least one uplink transmission for the one or more secondary cells, perform, using a second timing advance, a second uplink transmission via the one or more secondary cells.
18. The non-transitory computer-readable medium of claim 17 , wherein the instructions, when executed, further configure the wireless device to determine that the one or more secondary cells are out-of-sync, and to perform the second uplink transmission during a time that the one or more secondary cells are out-of-sync.
19. The non-transitory computer-readable medium of claim 17 , wherein the instructions, when executed, further configure the wireless device to:
based on the transmission timing difference exceeding the threshold, determine that a time alignment timer is expired; and
perform the second uplink transmission during a time that the time alignment timer is not running.
20. The non-transitory computer-readable medium of claim 17 , wherein the transmission timing difference comprises a difference between:
uplink transmission timing associated with the first cell group; and
uplink transmission timing associated with the second cell group.
21. The non-transitory computer-readable medium of claim 17 , wherein the transmission timing difference comprises a difference between:
a timing of a first synchronization signal; and
a timing of a second synchronization signal.
22. The non-transitory computer-readable medium of claim 17 , wherein the first timing advance is a non-zero timing advance and the second timing advance is a zero timing advance.
23. The non-transitory computer-readable medium of claim 17 , wherein the instructions, when executed, further configure the wireless device to:
receive a first timing advance command, wherein the first timing advance is based on the first timing advance command;
receive a second timing advance command; and
determine, based on the second timing advance command, the transmission timing difference.
24. The non-transitory computer-readable medium of claim 17 , wherein the second uplink transmission comprises a random access preamble.
25. A system comprising:
a base station; and
a wireless device,
wherein the base station is configured to transmit a first timing advance command, and
wherein the wireless device is configured to:
perform, using a first timing advance based on the first timing advance command, a first uplink transmission via one or more secondary cells associated with a first cell group;
based on a transmission timing difference between the first cell group and a second cell group exceeding a threshold, stop at least one uplink transmission for the one or more secondary cells; and
after stopping the at least one uplink transmission for the one or more secondary cells, perform, using a second timing advance, a second uplink transmission via the one or more secondary cells.
26. The system of claim 25 , wherein the wireless device is further configured to determine that the one or more secondary cells are out-of-sync, and to perform the second uplink transmission during a time that the one or more secondary cells are out-of-sync.
27. The system of claim 25 , wherein the wireless device is further configured to:
based on the transmission timing difference exceeding the threshold, determine that a time alignment timer is expired; and
perform the second uplink transmission during a time that the time alignment timer is not running.
28. The system of claim 25 , wherein the transmission timing difference comprises a difference between:
uplink transmission timing associated with the first cell group; and
uplink transmission timing associated with the second cell group.
29. The system of claim 25 , wherein the transmission timing difference comprises a difference between:
a timing of a first synchronization signal; and
a timing of a second synchronization signal.
30. The system of claim 25 , wherein the first timing advance is a non-zero timing advance and the second timing advance is a zero timing advance.
31. The system of claim 25 , wherein the wireless device is further configured to:
receive a second timing advance command; and
determine, based on the second timing advance command, the transmission timing difference.
32. The system of claim 25 , wherein the second uplink transmission comprises a random access preamble.