Beam failure recovery in unlicensed cells
A wireless device receives configuration parameters indicating a first value of a beam failure instance counter and a radio resource of a downlink signal. The wireless device determines the downlink signal is transmitted via the radio resource. The wireless device determines a beam failure instance based on: the determining the downlink signal is transmitted; and a received power of the downlink signal being less than a threshold value. The wireless device increments the beam failure instance counter based on the determining the beam failure instance.
1. A method comprising:
receiving, by a wireless device, configuration parameters indicating:
a first value of a beam failure instance counter; and
a radio resource of a downlink signal;
determining the downlink signal is transmitted via the radio resource based on one or more downlink listen before talk procedures for transmission of the downlink signal being successful in response to a received power of the downlink signal exceeding a first threshold value;
determining a beam failure instance based on:
the determining the downlink signal is transmitted; and
the received power of the downlink signal being less than a threshold value;
incrementing the beam failure instance counter based on the determining the beam failure instance; and
transmitting a beam failure recovery signal based on the beam failure instance counter reaching the first value.
2. The method of claim 1 , wherein the determining that the downlink signal is transmitted is due to the one or more downlink listen before talk procedures indicating a clear channel.
3. The method of claim 1 , wherein the downlink signal comprises a synchronization signal block.
4. The method of claim 1 , wherein the downlink signal comprises a channel state information reference signal.
5. The method of claim 1 , wherein the determining that the downlink signal is transmitted is based on one or more second threshold values.
6. The method of claim 1 , wherein the determining that the downlink signal is transmitted is based on the downlink signal being present in the radio resource.
7. The method of claim 1 , further comprising starting a beam failure recovery timer, with a second value, based on the beam failure instance counter having the first value.
8. The method of claim 7 , wherein the configuration parameters indicate the second value.
9. The method of claim 1 , further comprising starting a beam failure detection timer, with a third value, based on the determining the beam failure instance.
10. The method of claim 1 , wherein the beam failure recovery signal is a random access preamble.
11. 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 configuration parameters indicating:
a first value of a beam failure instance counter;
and a radio resource of a downlink signal;
determine the downlink signal is transmitted via the radio resource based on one or more downlink listen before talk procedures for transmission of the downlink signal being successful in response to a received power of the downlink signal exceeding a first threshold value;
determine a beam failure instance based on:
determining the downlink signal is transmitted; and the received power of the downlink signal being less than a threshold value;
increment the beam failure instance counter based on determining the beam failure instance; and
transmit a beam failure recovery signal based on the beam failure instance counter reaching the first value.
12. The wireless device of claim 11 , wherein the determining that the downlink signal is transmitted is due to one or more downlink listen before talk procedures indicating a clear channel.
13. The wireless device of claim 11 , wherein the downlink signal comprises a synchronization signal block.
14. The wireless device of claim 11 , wherein the downlink signal comprises a channel state information reference signal.
15. The wireless device of claim 11 , wherein the determining that the downlink signal is transmitted is based on one or more second threshold values.
16. The wireless device of claim 11 , wherein the determining that the downlink signal is transmitted is based on the downlink signal being present in the radio resource.
17. The wireless device of claim 11 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to start a beam failure recovery timer, with a second value, based on the beam failure instance counter having the first value.
18. The wireless device of claim 17 , wherein the configuration parameters indicate the second value.
19. The wireless device of claim 11 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to start a beam failure detection timer, with a third value, based on the determining the beam failure instance.
20. A system comprising: a base station; and
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 the base station, configuration parameters indicating:
a first value of a beam failure instance counter; and
a radio resource of a downlink signal;
determine the downlink signal is transmitted via the radio resource based on one or more downlink listen before talk procedures for transmission of the downlink signal being successful in response to a received power of the downlink signal exceeding a first threshold value;
determine a beam failure instance based on:
determining the downlink signal is transmitted; and the received power of the downlink signal being less than a threshold value;
increment the beam failure instance counter based on determining the beam failure instance; and
transmit a beam failure recovery signal based on the beam failure instance counter reaching the first value.