Method for NR Radio Link Monitoring (RLM) and Evaluation Period Determination

Abstract

Methods are proposed to define UE behavior for performing synchronization signal block (SSB) based radio link monitoring (RLM) and channel state information reference signal (CSI-RS) based RLM. In a first novel aspect, if CSI-RS based RLM-RS is not QCLed to any CORESET, then UE determines that CSI-RS RLM configuration is error and does not perform RLM accordingly. In a second novel aspect, SSB for RLM and RLM CSI-RS resources are configured with different numerologies. UE perform SSB based RLM and CSI-RS based RLM based on whether the SSB and CSI-RS resources are TDMed configured by the network. In a third novel aspect, when multiple SMTC configurations are configured to UE, UE determines an SMTC period and whether SMTC and RLM-RS are overlapped for the purpose of RLM evaluation period determination.

What is claimed is: 
     
         1 . A method, comprising:
 receiving synchronization signal block (SSB) configuration for radio link monitoring (RLM) by a user equipment (UE) in a new radio (NR) network, wherein the SSB occupies a first OFDM symbol having a first numerology;   receiving channel state information reference signal (CSI-RS) configuration for RLM by the UE, wherein the configured CSI-RS resource is allocated over a second OFDM symbol having a second numerology;   determining whether the SSB and the configured CSI-RS resource are Time Division Multiplexed (TDMed) responsive to the first numerology and the second numerology being different; and   performing SSB based RLM and CSI-RS based RLM using the SSB and CSI-RS configuration for RLM based on whether the SSB and the configured CSI-RS resource are TDMed.   
     
     
         2 . The method of  claim 1 , wherein the first numerology and the second numerology being different includes the first numerology and the second numerology having different subcarrier spacing (SCS) values. 
     
     
         3 . The method of  claim 1 , wherein the first numerology and the second numerology being different includes the first numerology and the second numerology having different cyclic-shift prefix (CP) lengths. 
     
     
         4 . The method of  claim 1 , wherein the performing SSB based RLM and CSI-RS based RLM based on whether the SSB and the configured CSI-RS resource are TDMed includes performing SSB based RLM and CSI-RS based RLM only when the SSB and the configured CSI-RS resource are TDMed. 
     
     
         5 . The method of  claim 1 , wherein the performing SSB based RLM and CSI-RS based RLM is further based on whether the UE supports simultaneous reception over different numerologies. 
     
     
         6 . The method of  claim 5 , wherein the performing SSB based RLM and CSI-RS based RLM based on whether the UE supports simultaneous reception over different numerologies includes performing SSB based RLM and CSI-RS based RLM only when the UE does NOT support simultaneous reception over different numerologies. 
     
     
         7 . The method of  claim 1 , further comprising:
 receiving SSB measurement timing configuration (SMTC) configuration for RLM by the UE; and   determining an RLM evaluation period for RLM according to the SMTC configuration for RLM based at least on an SMTC periodicity.   
     
     
         8 . The method of  claim 7 , wherein the SMTC configuration comprises an SMTC periodicity, an SMTC window duration, and a timing offset. 
     
     
         9 . The method of  claim 7 , wherein a first smtc1 and a second smtc2 are configured by the network, and wherein the RLM evaluation period is determined based on the shortest SMTC periodicity. 
     
     
         10 . The method of  claim 7 , wherein the determining the RLM evaluation period is further based on an RLM evaluation scaling factor for channel state information reference signal (CSI-RS) based RLM, and the RLM evaluation scaling factor is associated with whether CSI-RS resources and SMTC window durations are overlapped. 
     
     
         11 . A User Equipment (UE), comprising:
 a synchronization signal block (SSB) based radio link monitoring (RLM) configuration circuit that obtains SSB configuration for RLM in a new radio (NR) network, wherein the SSB occupies a first OFDM symbol having a first numerology;   a channel state information reference signal (CSI-RS) based RLM configuration circuit that obtains CSI-RS configuration for RLM, wherein configured CSI-RS resource is allocated over a second OFDM symbol having a second numerology;   an RLM control circuit that determines whether the SSB and the configured CSI-RS resource are Time Division Multiplexed (TDMed) responsive to the first numerology and the second numerology being different; and   an RLM handling circuit that performs SSB based RLM and CSI-RS based RLM using the SSB and CSI-RS configuration for RLM based on whether the SSB and the configured CSI-RS resource are TDMed.   
     
     
         12 . The UE of  claim 11 , wherein the first numerology and the second numerology being different includes the first numerology and the second numerology having different subcarrier spacing (SCS) values. 
     
     
         13 . The UE of  claim 11 , wherein the first numerology and the second numerology being different includes the first numerology and the second numerology having different cyclic-shift prefix (CP) lengths. 
     
     
         14 . The UE of  claim 11 , wherein the performing SSB based RLM and CSI-RS based RLM based on whether the SSB and the configured CSI-RS resource are TDMed includes performing SSB based RLM and CSI-RS based RLM only when the SSB and the configured CSI-RS resource are TDMed. 
     
     
         15 . The UE of  claim 11 , wherein the performing SSB based RLM and CSI-RS based RLM is further based on whether the UE supports simultaneous reception over different numerologies. 
     
     
         16 . The UE of  claim 15 , wherein the performing SSB based RLM and CSI-RS based RLM based on whether the UE supports simultaneous reception over different numerologies includes performing SSB based RLM and CSI-RS based RLM only when the UE does NOT support simultaneous reception over different numerologies. 
     
     
         17 . The UE of  claim 11 , further comprising:
 a receiver that receives SSB measurement timing configuration (SMTC) configuration for RLM, wherein the UE determines an RLM evaluation period for RLM according to the SMTC configuration for RLM based at least on an SMTC periodicity.   
     
     
         18 . The UE of  claim 17 , wherein the SMTC configuration comprises an SMTC periodicity, an SMTC window duration, and a timing offset. 
     
     
         19 . The UE of  claim 17 , wherein a first smtc1 and a second smtc2 are configured by the network, and wherein the RLM evaluation period is determined based on the shortest SMTC periodicity. 
     
     
         20 . The UE of  claim 17 , wherein the determining the RLM evaluation period is further based on an RLM evaluation scaling factor for channel state information reference signal (CSI-RS) based RLM, and the RLM evaluation scaling factor is associated with whether CSI-RS resources and SMTC window durations are overlapped.