Radio link failure detection of an unlicensed cell by a wireless device

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 an unlicensed cell;
• receive, via the unlicensed cell, downlink signals during a time window comprising a plurality of downlink transmission time intervals;
• determine whether the time window is used for radio link failure (RLF) detection of the unlicensed cell;
• increment a counter in response to:
• a radio link quality of the downlink signals being worse than a threshold during the time window;
• and
• the time window being used for the RLF detection of the unlicensed cell;
• detect an RLF based on the counter;
• and
• transmit a first message indicating the RLF.

A system comprising:

• a wireless device comprising:
• one or more first processors;
• and
• a first memory storing instructions that, when executed by the one or more first processors, cause the wireless device to:
• receive configuration parameters of an unlicensed cell;
• receive, via the unlicensed cell, downlink signals during a time window comprising a plurality of downlink transmission time intervals;
• determine whether the time window is used for radio link failure (RLF) detection of the unlicensed cell;
• increment a counter in response to:
• a radio link quality of the downlink signals being worse than a threshold during the time window;
• and
• the time window being used for the RLF detection of the unlicensed cell;
• detect an RLF based on the counter;
• and
• transmit a first message indicating the RL;
• a base station comprising:
• one or more second processors;
• and
• a second memory storing instructions that, when executed by the one or more second processors, cause the base station to:
• transmit the configuration parameters of the unlicensed cell;
• and
• transmit, via the unlicensed cell, the downlink signals during the time window comprising the plurality of downlink transmission time intervals.