Listen before talk procedure and bandwidth part switching

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 of a first bandwidth part (BWP) and a second BWP of an unlicensed cell;
• determine, with the first BWP being an active BWP, a first number of consecutive listen before talk (LBT) procedures, for a first channel of the active BWP, performed based on a contention window being a maximum contention window of a plurality of contention windows corresponding to the first channel;
• and
• based on switching from the first BWP to the second BWP as the active BWP, determine a second number of consecutive LBT procedures, for a second channel of the active BWP, performed based on the contention window being the maximum contention window of a plurality of contention windows corresponding to the second channel.

A system comprising:

• a base station comprising one or more first processors and first memory storing first instructions that, when executed by the one or more first processors, cause the base station to:
• transmit configuration parameters of a first bandwidth part (BWP) and a second BWP of an unlicensed cell;
• and
• a wireless device comprising one or more second processors and second memory storing second instructions that, when executed by the one or more second processors, cause the wireless device to:
• receive the configuration parameters of the first BWP and the second BWP of the unlicensed cell;
• determine, with the first BWP being an active BWP, a first number of consecutive listen before talk (LBT) procedures, for a first channel of the active BWP, performed based on a contention window being a maximum contention window of a plurality of contention windows corresponding to the first channel;
• and
• based on switching from the first BWP to the second BWP as the active BWP, determine a second number of consecutive LBT procedures, for a second channel of the active BWP, performed based on the contention window being the maximum contention window of a plurality of contention windows corresponding to the second channel.