Random Access Backoff Indicator

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:

• transmit, for a random access procedure, a first preamble via a cell comprising a first sub-band and a second sub-band;
• receive a random access response indicating:
• a first backoff indicator indicating a first backoff time interval of the first sub-band;
• and
• a second backoff indicator indicating a second backoff time interval of the second sub-band;
• determine a preamble retransmission for the random access procedure;
• select, as a backoff time interval, a shorter one of the first backoff time interval and the second backoff time interval;
• and
• perform, at a time based on the backoff time interval, a listen-before-talk procedure.

A base station and a wireless device, wherein:

• the base station comprises one or more processors of the base station and memory storing instructions of the base station that, when executed by the one or more processors of the base station, cause the base station to:
• receive, for a random access procedure, a first preamble via a cell comprising a first sub-band and a second sub-band;
• transmit a random access response indicating:
• a first backoff indicator indicating a first backoff time interval of the first sub-band;
• and
• a second backoff indicator indicating a second backoff time interval of the second sub-band;
• and
• the wireless device comprises one or more processors of the wireless device and memory storing instructions of the wireless device that, when executed by the one or more processors of the wireless device, cause the wireless device to:
• transmit the first preamble;
• receive the random access response;
• determine a preamble retransmission for the random access procedure;
• select, as a backoff time interval, a shorter one of the first backoff time interval and the second backoff time interval;
• and
• perform, at a time based on the backoff time interval, a listen-before-talk procedure.