Methods, apparatus and systems for radio link monitoring (rlm) in new radio (nr)

Abstract

Methods, apparatuses, and systems for radio link monitoring (RLM) implemented by a wireless transmit/receive unit (WTRU) are provided. A representative method for RLM includes mapping, by the WTRU, one or more RLM-RS resources to at least one BLER threshold of a plurality of BLER thresholds. The representative method also includes, for each respective RLM resource that is mapped, determining, by the WTRU, a BLER of the respective RLM-RS resource, and comparing the determined BLER of the respective RLM-RS resource with the at least one mapped BLER threshold associated with the respective RLM-RS resource. The representative method further includes generating, based on one or more of the comparisons, a set of in-sync indications and/or a set of out-of-sync indications, and indicating, by the WTRU, one or more attributes associated with the set of in-sync indications and/or the set of out-of-sync indications.

1 . A method implemented by a wireless transmit/receive unit (WTRU) configured for radio link monitoring (RLM), comprising:
 mapping, by the WTRU, one or more RLM reference signal (RLM-RS) resources to at least one Block Error Ratio (BLER) threshold of a plurality of BLER thresholds;   for each respective RLM resource that is mapped:
 determining, by the WTRU, a BLER of the respective RLM-RS resource, and 
 comparing the determined BLER of the respective RLM-RS resource with the at least one mapped BLER threshold associated with the respective RLM-RS resource; 
   generating, based on one or more of the comparisons, a set of in-sync indications and/or a set of out-of-sync indications; and   indicating, by the WTRU, one or more attributes associated with the set of in-sync indications and/or the set of out-of-sync indications.   
     
     
         2 . The method of  claim 1 , wherein a respective BLER threshold of the plurality of BLER threshold is associated with a service type. 
     
     
         3 . The method of  claim 2 , wherein the service type is any of: ultra-reliable low latency (URLLC), enhanced massive mobile broadband (eMBB), or enhanced machine-type communication (eMTC). 
     
     
         4 . The method of  claim 1 , wherein the one or more attributes indicate any of:
 a respective RLM-RS resource, an RLM-RS resource group, or an RLM-RS type associated with the set of in-sync indications and/or the set of out-of-sync indications;   a CORESET or a CORESET group associated with the set of in-sync indications and/or the set of out-of-sync indications;   a beam group associated with the set of in-sync indications and/or the set of out-of-sync indications; and   a respective BLER threshold associated with the set of in-sync indications and/or the set of out-of-sync indications.   
     
     
         5 . The method of  claim 1 , further comprising:
 obtaining, by the WTRU, a type of service associated with a communication; and   selecting, by the WTRU, the at least one BLER threshold in accordance with the obtained type of service.   
     
     
         6 . The method of  claim 1 , wherein:
 the mapping of the one or more RLM-RS resources includes mapping of each respective RLM-RS resource to one BLER threshold of the plurality of BLER thresholds; and   the comparing of the determined BLER of the respective RLM-RS resource with the at least one mapped BLER threshold includes comparing of the determined BLER of each respective RLM-RS resource to the at least one mapped BLER threshold.   
     
     
         7 . The method of  claim 1 , further comprising:
 grouping two or more of the RLM-RS resources that are associated with any of: one CORESET, a group of CORESETs, and a beam group;   determining a composite BLER specific to the grouped RLM-RS resources based on the determined BLER; and   comparing the composite BLER specific to the grouped RLM-RS resources with one of the at least one mapped BLER threshold.   
     
     
         8 . The method of  claim 1 , wherein the generating of the set of in-sync indications and/or the set of out-of-sync indications includes generating the set of one or more in-sync indications and/or the set of one or more out-of-sync indications for: (1) each comparison of the determined BLER of the respective RLM-RS resource with the at least one mapped BLER threshold associated with the respective RLM-RS resource, or (2) a set of comparisons associated with the grouped RLM-RS resources. 
     
     
         9 . The method of  claim 1 , wherein the generating of the set of in-sync indications and/or the set of out-of-sync indications includes generating the set of one or more in-sync indications and/or the set of one or more out-of-sync indications associated with: (1) the at least one mapped BLER threshold; (2) a subset of the at least one mapped BLER threshold; or (3) for each of the at least one mapped BLER threshold. 
     
     
         10 . The method of  claim 1 , wherein:
 the mapping of the one or more RLM-RS resources includes mapping each RLM-RS resource to two or more BLER thresholds of the plurality of BLER thresholds; and   the comparing of the determined BLER of the respective RLM-RS resource with the at least one mapped BLER threshold includes comparing of the determined BLER associated with each respective RLM-RS resource or a group of RLM-RS resources to the two or more mapped BLER thresholds.   
     
     
         11 . The method of  claim 1 , wherein the generating of the set of in-sync indications and/or the set of out-of-sync indications includes generating a composite set of in-sync indications and/or out-of-sync indications for each of the at least one mapped BLER thresholds or N composite sets of in-sync indications and/or out-of-sync indications for M BLER thresholds, where N and M are positive integer values, and N is less than or equal to M. 
     
     
         12 . The method of  claim 1 , further comprising:
 determining, prior to the mapping, a first set of BLER thresholds of the plurality of BLER thresholds to be mapped with the one or more RLM-RS resources.   
     
     
         13 . The method of  claim 12 , further comprising:
 determining, after the mapping, that a second set of BLER thresholds of the plurality of BLER thresholds is be mapped with the one or more RLM-RS resources and/or other RLM-RS resources; and   modifying from a mapping of the one or more RLM-RS resources with the first set of BLER thresholds to a different mapping of the one or more RLM-RS resources and/or the other RLM-RS resources with the second set of BLER thresholds or remapping the one or more RLM-RS resources and/or the other RLM-RS resources with the second set of BLER thresholds,   wherein the comparing of the determined BLER with the at least one mapped BLER threshold includes comparing the determined BLER of the respective RLM-RS resources with the second set of modified or remapped BLER thresholds.   
     
     
         14 - 15 . (canceled) 
     
     
         16 . The method of  claim 1 , further comprising:
 reconfiguring at least one BLER threshold of the plurality of BLER thresholds from a first BLER threshold to a second BLER threshold.   
     
     
         17 . The method of  claim 16 , wherein after the reconfiguring, the one or more attributes associated with the set of in-sync indications and/or the set of out-of-sync indications are based on a configuration of an RLM process prior to and after the reconfiguration. 
     
     
         18 - 25 . (canceled) 
     
     
         26 . A method, implemented by a wireless transmit/receive unit (WTRU), to transition from a first Radio Resource Control (RRC) configuration to a second RRC configuration, as an RCC reconfiguration, the method comprising:
 receiving, by the WTRU, the second RRC configuration indicating a first set of Block Error Ratio (BLER) thresholds that is different from one or more BLER thresholds indicated in the first RRC configuration;   generating, based on the first set of BLER thresholds after reception of the second RRC configuration, one or more in-sync indications and/or one or more out-of-sync indications; and   indicating, by the WTRU, one or more attributes associated with the one or more in-sync indications and/or the one or more out-of-sync indications.   
     
     
         27 . The method of  claim 26 , wherein indicating of the one or more attributes associated with the one or more in-sync indications and/or the one or more out-of-sync indications includes compensating, by the WTRU based on at least an existing RLM status, for a difference between the first RRC configuration and the second RRC configuration as part of the transition from the first RRC configuration to the second RRC configuration. 
     
     
         28 . The method of  claim 27 , wherein compensating for the difference between the first RRC configuration and the second RRC configuration includes any of: (1) applying a penalty to counters and/or timers to account for differences in an ongoing RLM process; (2) applying fairness to avoid a premature radio link failure (RLF); (3) updating an expiry of a timer to avoid an RLF until after expiry of the updated timer; or (4) continuing an RLM process or resetting an RLM process selectively based on one or more rules to avoid the premature RLF or a delayed RLF. 
     
     
         29 - 44 . (canceled) 
     
     
         45 . A method, implemented by a wireless transmit/receive unit (WTRU), to transition from a first Radio Resource Control (RRC) configuration having first BLER thresholds to a second RRC configuration having second BLER thresholds, the method comprising:
 receiving the second RRC configuration;   determining a compensation for a new RRC configuration process associated with the second RRC configuration during a transition to the second RRC configuration based on an existing RLM status;   determining whether a Radio Link Failure (RLF) has occurred based on the second BLER thresholds associated with the second RRC configuration and the determined compensation; and   sending, by the WTRU, a message, on condition that the RLF occurred.   
     
     
         46 . A wireless transmit/receive unit (WTRU) comprising a processor, a receiver, a transmitter, and memory configured to perform the method of any one of the preceding claims.