Time window for radio link failure detection of an unlicensed cell
A base station transmits, to a wireless device and via an unlicensed cell, downlink signals during a time window. The base station receives, from the wireless device, an RRC message indicating a radio link failure (RLF) of the unlicensed cell based on a counter, wherein the counter is incremented in response to a radio link quality of the downlink signals being worse than a threshold during the time window.
1. A method comprising:
transmitting, by a base station to a wireless device and via an unlicensed cell, downlink signals during a time window; and
receiving, from the wireless device, an RRC message indicating a radio link failure (RLF) of the unlicensed cell based on a counter, wherein the counter is incremented in response to a radio link quality of the downlink signals being worse than a threshold during the time window.
2. The method of claim 1 , further comprising performing a plurality of listen-before-talk (LBT) procedures during downlink transmission time intervals of the unlicensed cell.
3. The method of claim 2 , wherein the time window comprises the downlink transmission time intervals.
4. The method of claim 1 , wherein the time window is used for monitoring for an RLF of the unlicensed cell.
5. The method of claim 1 , further comprising transmitting one or more configuration parameters indicating:
a first number for the counter; and
a timer started in response to the counter reaching the first number.
6. The method of claim 1 , wherein the unlicensed cell is a primary secondary cell.
7. The method of claim 1 , wherein the RRC message is received via an RRC connection reestablishment request message.
8. 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 and via an unlicensed cell, downlink signals during a time window; and
receive, from the wireless device, an RRC message indicating a radio link failure (RLF) of the unlicensed cell based on a counter, wherein the counter is incremented in response to a radio link quality of the downlink signals being worse than a threshold during the time window.
9. The base station of claim 8 , wherein the instructions further cause the base station to perform a plurality of listen-before-talk (LBT) procedures during downlink transmission time intervals of the unlicensed cell.
10. The base station of claim 9 , wherein the time window comprises the downlink transmission time intervals.
11. The base station of claim 8 , wherein the time window is used for monitoring for an RLF of the unlicensed cell.
12. The base station of claim 8 , wherein the instructions further cause the base station to transmit one or more configuration parameters indicating:
a first number for the counter; and
a timer started in response to the counter reaching the first number.
13. The base station of claim 8 , wherein the unlicensed cell is a primary secondary cell.
14. The base station of claim 8 , wherein the RRC message is received via an RRC connection reestablishment request message.
15. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of a base station, cause the base station to:
transmit, to a wireless device and via an unlicensed cell, downlink signals during a time window; and
receive, from the wireless device, an RRC message indicating a radio link failure (RLF) of the unlicensed cell based on a counter, wherein the counter is incremented in response to a radio link quality of the downlink signals being worse than a threshold during the time window.
16. The non-transitory computer-readable medium of claim 15 , wherein the instructions further cause the base station to perform a plurality of listen-before-talk (LBT) procedures during downlink transmission time intervals of the unlicensed cell.
17. The non-transitory computer-readable medium of claim 16 , wherein the time window comprises the downlink transmission time intervals.
18. The non-transitory computer-readable medium of claim 15 , wherein the time window is used for monitoring for an RLF of the unlicensed cell.
19. The non-transitory computer-readable medium of claim 15 , wherein the instructions further cause the base station to transmit one or more configuration parameters indicating:
a first number for the counter; and
a timer started in response to the counter reaching the first number.
20. The non-transitory computer-readable medium of claim 15 , wherein the RRC message is received via an RRC connection reestablishment request message.