Radio link monitoring and radio resource management measurement procedures for NR-U

1 . A wireless transmit receive unit (WTRU) comprising a processor and memory, the processor and memory configured to:

determine one or more sets of radio link failure reference signals in an active bandwidth part of a carrier associated with unlicensed spectrum;

receive downlink control information (DCI), the DCI comprising information indicating whether or not resources corresponding to the one or more sets of radio link failure reference signals have been acquired;

estimate a link quality based on of the one or more sets of radio link failure reference signals that occurred during at least a first period of time where the resources corresponding to the one or more sets of radio link failure reference signals were acquired;

determine that the resources corresponding to the one or more sets of radio link failure reference signals were not acquired for at least one transmission opportunity associated with the one or more sets of radio link failure reference signals;

determine not to generate an in-sync indication corresponding to at least a second period of time associated with the at least one transmission opportunity where the resources corresponding to the one or more sets of radio link failure reference signals were not acquired; and

evaluate for radio link failure based on at least the link quality estimated based on the one or more sets of radio link failure reference signals that occurred during at least the first period of time where the resources corresponding to the one or more sets of radio link failure reference signals were successfully acquired.

2 . The WTRU of claim 1 , wherein the processor and memory being configured to declare radio link failure comprises the processor and memory being configured to:

determine that a number of consecutive out-of-sync indications has been detected based on the measurements of the one or more sets of radio link failure reference signals that occurred during at least the first period of time where the resources corresponding to the one or more sets of radio link failure reference signals was successfully acquired;

start a timer based on determining that the number of consecutive out-of-sync indications has been detected; and

declare radio link failure based on expiration of the timer.

3 . The WTRU of claim 2 , wherein the processor and memory determine not to generate the in-sync indication corresponding to at least the second period of time associated with the at least one transmission opportunity where the resources corresponding to the one or more sets of radio link failure reference signals were not acquired between detecting at least two of the consecutive out-of-sync indications.

4 . The WTRU of claim 1 , wherein the processor and memory are configured to switch from the active bandwidth part to another bandwidth part based on declaring radio link failure.

5 . The WTRU of claim 1 , wherein the DCI indicates that the resources corresponding to the one or more sets of radio link failure reference signals have been acquired for a duration of a channel occupancy time.

6 . The WTRU of claim 1 , wherein the DCI is associated with a common or group radio network temporary identifier.

7 . The WTRU of claim 1 , wherein the DCI indicates that a first subband was successfully acquired and that a second subband was not successfully acquired.

8 . The WTRU of claim 1 , wherein the one or more sets of radio link failure reference signals to be used for radio link failure detection comprises a synchronization signal/physical broadcast channel (SS/PBCH) block (SSB).

9 . The WTRU of claim 1 , wherein the processor and memory are configured to determine not to generate the in-sync indication corresponding to at least the second period of time associated with the at least one transmission opportunity where the resources corresponding to the one or more sets of radio link failure reference signals were not acquired based on being configured to determine that one or more synchronization signal/physical broadcast channel (SS/PBCH) block (SSB) transmissions were not successfully performed.

10 . The WTRU of claim 1 , wherein the processor and memory are configured to, subsequent to the declaration of radio link failure based on at least the measurements of the one or more sets of radio link failure reference signals that occurred during at least the first period of time where the resources corresponding to the one or more sets of radio link failure reference signals was successfully acquired:

select a resource of the resources corresponding to the one or more sets of radio link failure reference signals that have been acquired; and

initiate a radio resource control reestablishment procedure with the selected resource.

11 . A method implemented by a wireless transmit receive unit (WTRU), the method comprising:

determining one or more sets of radio link failure reference signals in an active bandwidth part of a carrier associated with unlicensed spectrum;

receiving downlink control information (DCI), the DCI indicating that resources corresponding to the one or more sets of radio link failure reference signals have been acquired during a first period of time;

perform one or more measurements of the one or more sets of radio link failure reference signals that occurred during at least the first period of time;

determining that the resources corresponding to the one or more sets of radio link failure reference signals were not acquired for at least one transmission opportunity associated with the one or more sets of radio link failure reference signals;

determining not to generate an in-sync or out-of-sync indication corresponding to at least a second period of time associated with the at least one transmission opportunity where the resources corresponding to the one or more sets of radio link failure reference signals were not acquired; and

declaring radio link failure based on at least the measurements of the one or more sets of radio link failure reference signals that occurred during at least the first period of time where the resources corresponding to the one or more sets of reference signals were successfully acquired.

12 . The method of claim 11 , further comprising:

determining that a number of consecutive out-of-sync indications has been detected based on the measurements of the one or more sets of radio link failure reference signals that occurred during at least the first period of time where the resources corresponding to the one or more sets of at least the first period reference signals was successfully acquired;

starting a timer based on determining that the number of consecutive out-of-sync indications has been detected; and

declaring radio link failure based on expiration of the timer.

13 . The method of claim 12 , wherein the WTRU determines not to generate the in-sync or out-of-sync indication corresponding to at least the second period of time associated with the at least one transmission opportunity where the resources corresponding to the one or more sets of radio link failure reference signals were not acquired between detecting at least two of the consecutive out-of-sync indications.

14 . The method of claim 11 , wherein the DCI indicates that the resources corresponding to the one or more sets of radio link failure reference signals have been acquired for a duration of a channel occupancy time.

15 . The method of claim 11 , wherein the DCI is associated with a common or group radio network temporary identifier.

16 . The method of claim 11 , wherein the DCI indicates that a first subband was successfully acquired and that a second subband was not successfully acquired.

17 . The method of claim 11 , wherein the one or more sets of radio link failure reference signals to be used for radio link failure detection comprises a synchronization signal/physical broadcast channel (SS/PBCH) block (SSB).

18 . The method of claim 11 , wherein determining not to generate the in-sync or out-of-sync indication corresponding to at least the second period of time associated with the at least one transmission opportunity where the resources corresponding to the one or more sets of radio link failure reference signals were not acquired is based on determining that one or more synchronization signal/physical broadcast channel (SS/PBCH) block (SSB) transmissions were not successfully performed.

19 . The method of claim 12 , further comprising, subsequent to the declaration of radio link failure based on at least the measurements of the one or more sets of radio link failure reference signals that occurred during at least the first period of time where the resources corresponding to the one or more sets of radio link failure reference signals was successfully acquired:

selecting a resource of the resources corresponding to the one or more sets of radio link failure reference signals that have been acquired; and

initiating a radio resource control reestablishment procedure with the selected resource.

20 . A wireless transmit receive unit (WTRU) comprising a processor and memory, the processor and memory configured to:

determine one or more sets of radio link failure reference signals in an active bandwidth part of a carrier associated with unlicensed spectrum;

receive downlink control information (DCI), the DCI indicating that resources corresponding to the one or more sets of radio link failure reference signals have been acquired during a first period of time;

perform one or more measurements of the one or more sets of radio link failure reference signals that occurred during at least the first period of time;

determine that the resources corresponding to the one or more sets of radio link failure reference signals were not acquired for at least one transmission opportunity associated with the one or more sets of radio link failure reference signals;

wherein an in-sync or out-of-sync indication for radio link failure detection for a period of time associated with the at least one transmission opportunity is not generated based on the one or more sets of reference signals not being acquired; and

declare radio link failure based on at least the measurements of the one or more sets of radio link failure reference signals that occurred during at least the first period of time where the resources corresponding to the one or more sets of radio link failure reference signals was successfully acquired.