Cell and bandwidth part operations in unlicensed bands
A wireless device receives one or more messages comprising a parameter indicating a first value of a listen before talk (LBT) counter. The LBT counter is incremented based on an LBT procedure indicating an LBT failure for an uplink transmission via a first bandwidth part. Based on the LBT counter reaching the first value, a switch is made from the first bandwidth part to a second bandwidth part as an active bandwidth part.
1. A method comprising:
receiving, by a wireless device, a radio resource control (RRC) message comprising configuration parameters associated with a first bandwidth part (BWP) of a cell and a second BWP of the cell, and a first parameter indicating a first value associated with a listen before talk (LBT) counter for the cell;
performing a first LBT procedure for a first uplink transmission via the first BWP;
incrementing the LBT counter based on determination that the first LBT procedure fails; and
switching from the first BWP to a second BWP as an active BWP, based on determination that the LBT counter reaches the first value,
wherein the first value is used to determine after how many consistent uplink LBT failure events the wireless device triggers uplink LBT failure recovery.
2. The method of claim 1 , further comprising transmitting one or more uplink signals via the second BWP based on the switching.
3. The method of claim 1 , further comprising resetting the LBT counter based on a second LBT procedure for a second uplink transmission indicating a clear channel.
4. The method of claim 1 , wherein a value of the LBT counter remains unchanged based on a second LBT procedure for a second uplink transmission indicating a clear channel.
5. The method of claim 1 , wherein the first uplink transmission comprises one or more of:
a sounding reference signal,
a demodulation reference signal,
a phase tracking reference signal,
a physical random access channel signal,
a physical uplink shared channel signal, or
a physical uplink control channel signal.
6. The method of claim 1 , wherein the first uplink transmission is transmission of one or more transport blocks.
7. The method of claim 1 , wherein the first uplink transmission is based on a dynamic grant or a configured grant.
8. The method of claim 1 ,
wherein, the RRC message further comprises a BWP inactivity timer of the cell, and
wherein, the first BWP is switched to a default BWP, based on determination that the BWP inactivity timer of the cell has expired.
9. 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 a radio resource control (RRC) message comprising configuration parameters associated with a first bandwidth part (BWP) of a cell and a second BWP of the cell, and a first parameter indicating a first value associated with a listen before talk (LBT) counter for the cell,
perform a first LBT procedure for a first uplink transmission via the first BWP,
increment the LBT counter based on determination that the first LBT procedure fails, and
switch from the first BWP to a second BWP as an active BWP, based on determination that the LBT counter reaches the first value,
wherein the first value is used to determine after how many consistent uplink LBT failure events the wireless device triggers uplink LBT failure recovery.
10. The wireless device of claim 9 , wherein the instructions further cause the wireless device to transmit one or more uplink signals via the second BWP based on the switch.
11. The wireless device of claim 9 , wherein the instructions further cause the wireless device to reset the LBT counter based on a second LBT procedure for a second uplink transmission indicating a clear channel.
12. The wireless device of claim 9 , wherein a value of the LBT counter remains unchanged based on a second LBT procedure for a second uplink transmission indicating a clear channel.
13. The wireless device of claim 9 , wherein the first uplink transmission comprises one or more of:
a sounding reference signal,
a demodulation reference signal,
a phase tracking reference signal,
a physical random access channel signal,
a physical uplink shared channel signal, or
a physical uplink control channel signal.
14. The wireless device of claim 9 , wherein the first uplink transmission is transmission of one or more transport blocks.
15. The wireless device of claim 9 , wherein the first uplink transmission is based on a dynamic grant or a configured grant.
16. The wireless device of claim 9 ,
wherein, the RRC message further comprises a BWP inactivity timer of the cell, and
wherein, the first BWP is switched to a default BWP, based on determination that the BWP inactivity timer of the cell has expired.