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 one or more bandwidth parts (BWPs) of a cell, a first parameter indicating a first value associated with a listen before talk (LBT) counter for the cell, and a second value of a BWP inactivity timer of the cell;
performing a first LBT procedure for a first uplink transmission via a first BWP;
incrementing the LBT counter for indicating a busy channel based on the first LBT procedure;
switching from the first BWP to a second BWP as an active BWP, in case that the LBT counter reaches the first value; and
switching from the first BWP to a default BWP as the active BWP, in case that the BWP inactivity timer of the cell has expired,
wherein the first value determines a number of consistent uplink LBT failures that triggers an 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. 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 one or more bandwidth parts (BWPs) of a cell, a first parameter indicating a first value associated with a listen before talk (LBT) counter for the cell, and a second value of a BWP inactivity timer of the cell;
perform a first LBT procedure for a first uplink transmission via a first BWP;
increment the LBT counter for indicating busy channel based on the first LBT procedure;
switch from the first BWP to a second BWP as an active BWP, in case that the LBT counter reaches the first value; and
switch from the first BWP to a default BWP as the active BWP, in case that the BWP inactivity timer of the cell has expired,
wherein the first value determines a number of consistent uplink LBT failures that triggers an uplink LBT failure recovery.
9. The wireless device of claim 8 , wherein the instructions further cause the wireless device to transmit one or more uplink signals via the second BWP based on the switch.
10. The wireless device of claim 8 , 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.
11. The wireless device of claim 8 , wherein a value of the LBT counter remains unchanged based on a second LBT procedure for a second uplink transmission indicating a clear channel.
12. The wireless device of claim 8 , 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.
13. The wireless device of claim 8 , wherein the first uplink transmission is transmission of one or more transport blocks.
14. The wireless device of claim 8 , wherein the first uplink transmission is based on a dynamic grant or a configured grant.
15. A system comprising:
a base station comprising: one or more first processors and memory storing instructions that, when executed by the one or more first processors, cause the base station to transmit a radio resource control (RRC) message comprising configuration parameters associated with one or more bandwidth parts (BWPs) of a cell, a first parameter indicating a first value associated with a listen before talk (LBT) counter for the cell, and a second parameter indicating a second value of a BWP inactivity timer of the cell; and
a wireless device comprising one or more second processors and memory storing instructions that, when executed by the one or more second processors, cause the wireless device to:
receive the RRC message;
perform an LBT procedure for an uplink transmission via a first BWP;
increment the LBT counter for indicating busy channel based on the LBT procedure;
switch from the first BWP to a second BWP as an active BWP, in case that the LBT counter reaches the first value; and
switch from the first BWP to a default BWP as the active BWP, in case that the BWP inactivity timer of the cell has expired,
wherein the first value determines a number of consistent uplink LBT failures that triggers an uplink LBT failure recovery.