Methods and apparatuses for selecting, determining, and supporting auxiliary beams based on synchronization signal / physical broadcast channel blocks

Abstract

Auxiliary beams may be determined based on SSBs. A WTRU may determine a first set of L1-RSRP values for each CSI-RS using SSB Rx beams. The WTRU may determine an L1-RSRP difference between L1-RSRPs of an SSB and a CSI-RS which may be QCL-related. If the L1-RSRP difference for a CSI-RS resource of the first set is greater than the first threshold, the WTRU may send a CRI indicating the CSI-RS. The WTRU may measure CSI-RS resources of the second CSI-RS resource set and determine a second best Rx beam and a second L1-RSRP. If the difference between the second L1-RSRP value and L1-RSRP value of the first set of L1-RSRP values is greater than the second threshold, the WTRU may send an indication to the gNB requesting a new CSI report and / or indicating the L1-RSRP difference.

Description

METHODS AND APPARATUSES FOR SELECTING, DETERMINING, AND SUPPORTING AUXILIARY BEAMS BASED ON SYNCHRONIZATION SIGNAL / PHYSICAL BROADCAST CHANNEL BLOCKS CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Number 63 / 517,939, filed August 7, 2023, which is hereby incorporated herein by reference in its entirety. BACKGROUND

[0002] Beam management for wireless telecommunications networks may be complex and utilize extensive resources. Beam management may involve computations in both the time and spatial domains. Beam management may include beam selection. Beam selection may involve beam sweeps for entities within a network infrastructure (e.g., gNB) and entities not part of the network infrastructure (e.g., mobile devices). A network entity may perform Tx (transmit) beam sweeps to select appropriate beams. A mobile entity may perform Rx (receive) beam sweeps to select appropriate beams. Beam selection may be accomplished using reference signals (RSs). To ensure quality beam selection, accurate Tx beam quality measurements are utilized, which involve measuring Tx beam reference signals using appropriate Rx beams. Since Rx beam selection involves Rx beam sweep on the mobile device side, the procedure may create reference signal (RS) resource overhead on the network side and RS measurement overhead on the mobile device side. SUMMARY

[0003] A UE also may be referred to herein as a wireless transmit / receive unit (WTRU). Throughout the Specification and Figures, the terms UE and WTRU may be used interchangeably. Described herein are methods and apparatuses for selecting, determining, and supporting auxiliary Rx (receive) beams. Various examples are described herein. Various examples may utilize artificial intelligence (AI), machine learning (ML), or a combination thereof. One example includes methods and apparatuses for determining, monitoring, and maintaining auxiliary Rx beams based on synchronization signal / physical broadcast channel blocks (SSBs). Another example includes methods and apparatuses for determining, monitoring, and maintaining auxiliary Rx beams based on time. Yet another example includes methods and apparatuses for determining, monitoring, and maintaining auxiliary Rx beams based on positioning.

[0004] Regarding methods and apparatuses for determining, monitoring, and maintaining auxiliary Rx beams based on SSBs, a WTRU may be configured with various parameters and information, which may include an SSB resource set, TCI (transmission configuration indicator) states, a first channel state information – reference signal 1   (CSI-RS) resource set in which each CSI-RS is associated with a TCI state, or any appropriate combination thereof. The TCI state may include an SSB as a new quasi co-location (QCL) type (e.g., wide beam) reference RS. The parameters and information further may include a second CSI-RS resource set (e.g., aperiodic) (e.g., where all CSI- RS resources are configured with repetition), a first threshold for L1-RSRP (layer-1 – reference signal received power) difference, a second threshold for a new CSI reporting, or any appropriate combination thereof.

[0005] The WTRU may receive / detect one or more SSBs of the SSB resource set and may determine a first set of best Rx beams (e.g., through exhaustive beam search) for each SSB of the SSB resource set. The WTRU may measure the CSI-RSs of the first CSI-RS resource set using for each CSI-RS, the Rx beam of the first set of best Rx beams determined for the SSBs configured as a QCL reference for the CSI-RS, and may determine a first set of L1- RSRP values for each CSI-RS in the first CSI-RS resource set.

[0006] The WTRU may determine an L1-RSRP difference based on the measurement. For example, the WTRU may determine the L1-RSRP difference between L1-RSRPs of an SSB (e.g., highest RSRP SSB) and a CSI-RS (e.g., worst) which are QCL-related with the same SSB. The WTRU may determine a L1-RSRP difference between L1-RSRPs of a CSI-RS (e.g., best) associated with an SSB (e.g., highest RSRP SSB) and one or more other CSI- RSs which are QCL-related with the same SSB. The WTRU may determine an L1-RSRP difference based on other conditions and actions, such as, for example, an average L1-RSRP of CSI-RSs QCL-related with an SSB for triggering exhaustive Rx beam, e.g., a condition to turn on or off this procedure.

[0007] The WTRU may report the first set of L1-RSRP values of the first CSI-RS resource set.

[0008] If the determined L1-RSRP difference for a CSI-RS resource of the first set is greater than the first threshold, the WTRU may send a CSI-RS resource indicator (CRI) indicating the CSI-RS resource of the first set whose L1-RSRP is greater than the first threshold and a request to the gNB requesting transmission of at least one CSI-RS in the second CSI-RS resource set (e.g., to determine a second best Rx beam for the indicated CSI-RS resource of the first set).

[0009] The WTRU may measure the at least one CSI-RS resources of the second CSI-RS resource set and may determine a second-best Rx beam and a second L1-RSRP value (e.g., based on the second best Rx beam) for the indicated CSI-RS resource of the first set.

[0010] If the second L1-RSRP value of the indicated CSI-RS resource of the first set satisfies a condition (e.g., a difference between the second L1-RSRP value and L1-RSRP value of the first set of L1-RSRP values (e.g., associated with the same CSI-RS resource) > the second threshold),

[0011] The WTRU may send an indication to the gNB indicating a change (e.g., requesting a new CSI report and / or indicating the L1-RSRP difference). 2

[0012] Based on the L1-RSRP values (e.g., average difference of second L1-RSRP value and L1-RSRP values of the first set of L1-RSRP values), the WTRU may trigger exhaustive search (i.e., send a request to gNB for transmission of all the RSs of the second RS resource set) for determining a second set of best Rx beams of all CSI- RSs related to an SSB.

[0013] Regarding methods and apparatuses for determining, monitoring, and maintaining auxiliary Rx beams based on time, a WTRU may be configured with various parameters and information, which may include TCI-states, a first RS resource set in which each RS is associated with a TCI state, a second RS resource set (e.g., aperiodic) (e.g., where all RS resources are configured with repetition), a time threshold RX_TIMER_MAX, a time offset T_MINUS, a threshold for L1-RSRP difference, or any appropriate combination thereof. The WTRU may maintain an RX_TIMER counting the time (e.g., symbols / slots / ms) from the previous instance of Rx beams exhaustive search- based determination.

[0014] If RX_TIMER < RX_TIMER_MAX, the WTRU may measures RSs of the first RS resource set using the TCI-states (e.g., using a first set of Rx beams determined from the configured TCI-states) and may determine a first set of L1-RSRP values for each RS of the first RS resource set. The WTRU may report to the gNB the measured first set of L1-RSRP values, and may send a CRI (e.g., CRI of the CSI-RS resource with the highest L1-RSRP) and a request to the gNB requesting transmission of at least one RS in the second RS resource set (e.g., to determine a second Rx beam for the RS resource associated with the indicated CRI).

[0015] The WTRU may measure the at least one RS of the second RS resource set and determines a second best Rx beams and a second L1-RSRP value of the RS resource associated with the indicated CRI based on the determined second best Rx beam.

[0016] Based on the first and second L1-RSRP values of the RS resource associated with the indicated CRI (e.g., if the difference between the second L1-RSRP value and the first L1-RSRP value of the RS resource associated with the indicated CRI, is greater than the threshold), the WTRU may reset the RX_TIMER and triggers reset stage. The WTRU may report the second L1-RSRP value and RX_TIMER reset (e.g., as part of next CSI report).

[0017] Based on the first and second L1-RSRP values of the RS resource associated with the indicated CRI (e.g., if the difference between the second L1-RSRP value and the first L1-RSRP value of the RS resource associated with the indicated CRI, is less than or equal to the threshold), the WTRU may subtract the time offset value, T_MINUS, from the RX_TIMER. The WTRU may report second L1-RSRP value and RX_TIMER value (e.g., as part of next CSI report).

[0018] During a reset stage, if RX_TIMER >= RX_TIMER_MAX OR reset is triggered, the WTRU may send a request to the gNB requesting transmission of all RSs of the second RS resource set (e.g., for new round of Rx beam training). (e.g., implicit request via reporting some measurement or parameter through CSI-Report e.g., RX_TIMER 3   reset). The WTRU may measure the transmitted resources of the second RS resource set and determines a second set of best Rx beams (e.g., one for each RS) and a second set of L1-RSRP values of the RSs based on the second set of best Rx beams. The WTRU may report to gNB the measured second set of L1-RSRP values (e.g., via sending a request for a resource for CSI-Report).

[0019] Regarding methods and apparatuses for determining, monitoring, and maintaining auxiliary Rx beams based on positioning, a WTRU may be configured with various parameters and information, which may include TCI- states, a first RS resource set where each RS is associated with a TCI state, a second RS resource set (e.g., aperiodic) (e.g., where all RS resources are configured with repetition), a threshold for position difference, a threshold for orientation difference, a threshold for L1-RSRP difference, the association between the first RS resources of the first RS resource set and the second RS resources of the second RS resource set, or any appropriated combination thereof.

[0020] The WTRU may measure RSs of the first RS resource set using the TCI-states (e.g., using a first set of Rx beams determined from the configured TCI-states) and determines its relative position (from gNB), orientation and a first set of L1-RSRP values. The STRU may determine positioning / movement orientation information through other means e.g., through location services (LC). The WTRU may maintain REF_POSITION and REF_ORIENTATION parameters. If REF_POSITION / ORIENTATION not set, the WTRU may set REF_POSITION / ORIENTATION = current position / orientation.

[0021] The WTRU may report a first set of L1-RSRP values and based on WTRU’s relative position and orientation (e.g., If |WTRU position – REF_POSITION| > threshold OR |WTRU orientation – REF_ORIENTATION| > threshold), the WTRU may send an indication indicating |WTRU position / orientation – REF_POSITION / ORIENTATION| > threshold. The WTRU may send a request to the gNB requesting at least one RS of the second RS resource set (e.g., to determine at least one second best Rx beams) by indicating a beam index (CRI, SSB index) of a WTRU-determined beam from the first RS resource set (e.g., CRI of the RS with highest L1- RSRP) or a beam index of a beam from the second RS resource set configured to be associated with the WTRU- determined beam of the first RS resource set.

[0022] The WTRU may receive a confirmation and indication of the RSs from second RS resource set to be transmitted (e.g., bit map). The WTRU may receive and may measure the at least one second RS resources and determines a second Rx beam (e.g., second best Rx beams) and a second L1-RSRP value based on the second best Rx beam for the WTRU-determined and indicated beam index.

[0023] The WTRU may report the second L1-RSRP value to the gNB (e.g., as part of next CSI-Report). Based on the second L1-RSRP (e.g., if the difference between the second L1-RSRP value and the first L1-RSRP value for the WTRU-determined and indicated beam index is greater than threshold), the WTRU may trigger the reset stage. 4

[0024] Based on the second L1-RSRP value (e.g., if the difference between the second L1-RSRP value and the first L1-RSRP value for the WTRU-determined and indicated beam index is less than or equal to the threshold), the WTRU may update REF_POSITION and REF_ORIENTATION parameters with its current position and orientation, respectively.

[0025] With respect to the reset stage, the WTRU may send a request to the gNB requesting the transmission of all RSs in the second RS resource set (e.g., for new round of Rx beam training). (e.g., implicit request via reporting some measurement or parameter through CSI-Report e.g., WTRU indicating position / orientation change). The WTRU may measure the transmitted resources of the second RS resource set and may determine a second set of best Rx beams (e.g., one for each RS) and second set of L1-RSRP values of the RSs based on the second set of best Rx beams. The WTRU may determine its relative position, orientation and may update its REF_POSITION and REF_ORIENTATION parameters with its current position and orientation, respectively. The WTRU may report to gNB the measured second set of L1-RSRP values (e.g., via sending a request for a resource for CSI-Report).

[0026] As described herein, auxiliary beams may be determined based on SSBs. A WTRU may determine a first set of L1-RSRP values for each CSI-RS using SSB Rx beams. The WTRU may determine an L1-RSRP difference between L1-RSRPs of an SSB and a CSI-RS which may be QCL-related. If the L1-RSRP difference for a CSI-RS resource of the first set is greater than the first threshold, the WTRU may send a CRI indicating the CSI-RS. The WTRU may measure CSI-RS resources of the second CSI-RS resource set and determine a second best Rx beam and a second L1-RSRP. If the difference between the second L1-RSRP value and L1-RSRP value of the first set of L1-RSRP values is greater than the second threshold, the WTRU may send an indication to the gNB requesting a new CSI report and / or indicating the L1-RSRP difference.

[0027] An example WTRU for determining, monitoring, and / or maintaining beams may comprise a transceiver and a processor. The processor may be configured to measure a plurality of channel state information (CSI) reference signals (RSs) of a first CSI-RS resource set using a first receive (Rx) beam to determine a first set of layer- 1 (L1) reference signal received power (RSRP) values for each CSI-RS resource of the first CSI-RS resource set. The processor may be configured to determine a L1-RSRP difference of a first CSI-RS resource of the first CSI-RS resource set based on the L1-RSRP values of the CSI-RS set. The processor may be configured to, based on the determined L1-RSRP difference being greater than a first threshold, send, via the transceiver, a CSI-RS resource indicator (CRI) comprising an indication of the CSI-RS resource of the first CSI-RS resource set having an L1-RSRP value resulting in the L1-RSRP difference being greater than the first threshold; and send a request, via the transceiver, for at least one CSI-RS resource of a second CSI-RS resource set. The processor may be configured to measure a CSI-RS of the at least one CSI-RS resource of the second CSI-RS resource set to determine a second Rx beam and a second L1-RSRP value associated with the first CSI-RS resource of the first CSI-RS resource set. The processor may be configured to, based on the first L1-RSRP value and the second L1-RSRP value, determine the 5   second Rx beam. The processor may be configured to receive, via the transceiver, one or more synchronization signal / physical broadcast channel blocks (SSBs) of an SSB resource set and determine the first Rx beam based on a search of each SSB of the SSB resource set. The second Rx beam may be determined based on CSI-RSs associated with the SSB resource set. The L1-RSRP difference of the first CSI-RS resource may be between an L1- RSRP of an SSB of the SSB resource set and a respective measured L1-RSRP value. The processor may be configured to send a request, via the transceiver, for all CSI-RSs of the second CSI-RS resource set, use a plurality of Rx beams to measure CSI-RSs of the second CSI-RS resource set, and determine the second Rx beam based on measuring the CSI-RSs of the second CSI-RS resource set, wherein the second Rx beam is associated with an Rx beam of the plurality of Rx beams having a highest RSRP value. The processor may be configured to send a request, via the transceiver, for all CSI-RSs of the second CSI-RS resource set based on an average difference of the second L1-RSRP value and L1-RSRP values of the first set of L1-RSRP values being greater than a second threshold. The processor may be configured to, based on a difference between the first L1-RSRP value and the second L1-RSRP value being greater than a second threshold, send a request, via the transceiver, for a CSI report. The processor may be configured to, based on a difference between the first L1-RSRP value and the second L1- RSRP value being greater than a second threshold, send, via the transceiver, an indication of the difference between the first L1-RSRP value and the second L1-RSRP value. The WTRU may be configured to receive, via the transceiver, configuration information comprising at least one of a synchronization signal / physical broadcast channel block (SSB) resource set, a transmission configuration indicator (TCI) state, a first CSI-RS resource set wherein each CSI-RS is associated with a TCI state, a reference RS, a second CSI-RS resource set, the first threshold, or a second threshold. Determining the first set of L1-RSRP values may comprise determining a difference between a highest L1-RSRP value of a CSI-RS resource of the CSI-RS resource set configured as a quasi co-location (QCL) type reference signal RS and a lowest L1-RSRP value of a CSI-RS resource of the CSI-RS resource set configured as a QCL type RS. Determining the first set of L1-RSRP values may comprise determining a difference between a highest L1-RSRP value of a CSI-RS of the CSI-RS resource set configured as a quasi co-location (QCL) type RS and at least one other L1-RSRP value of a CSI-RS of the CSI-RS resource set configured as a QCL type RS.

[0028] An example method for determining, monitoring, and / or maintaining beams may be performed by a WTRU. The method may comprise measuring a plurality of channel state information (CSI) reference signals (RSs) of a first CSI-RS resource set using a first receive (Rx) beam to determine a first set of layer-1 (L1) reference signal received power (RSRP) values for each CSI-RS resource of the first CSI-RS resource set. The method may comprise determining a L1-RSRP difference of a first CSI-RS resource of the first CSI-RS resource set based on the L1-RSRP values of the CSI-RS set. The method may comprise, based on the determined L1-RSRP difference being greater than a first threshold, sending a CSI-RS resource indicator (CRI) comprising an indication of the CSI-RS resource of the first CSI-RS resource set having an L1-RSRP value resulting in the L1-RSRP difference being greater than the first threshold; and sending a request for at least one CSI-RS resource of a second CSI-RS resource 6   set. The method may comprise measuring a CSI-RS of the at least one CSI-RS resource of the second CSI-RS resource set to determine a second Rx beam and a second L1-RSRP value associated with the first CSI-RS resource of the first CSI-RS resource set. The method may comprise, based on the first L1-RSRP value and the second L1-RSRP value, determining the second Rx beam. The method may comprise receiving one or more synchronization signal / physical broadcast channel blocks (SSBs) of an SSB resource set and determine the first Rx beam based on a search of each SSB of the SSB resource set. The second Rx beam may be determined based on CSI-RSs associated with the SSB resource set. The L1-RSRP difference of the first CSI-RS resource may be between an L1-RSRP of an SSB of the SSB resource set and a respective measured L1-RSRP value. The method may comprise sending a request for all CSI-RSs of the second CSI-RS resource set, use a plurality of Rx beams to measure CSI-RSs of the second CSI-RS resource set, and determining the second Rx beam based on measuring the CSI-RSs of the second CSI-RS resource set, wherein the second Rx beam is associated with an Rx beam of the plurality of Rx beams having a highest RSRP value. The method may comprise sending a request for all CSI-RSs of the second CSI-RS resource set based on an average difference of the second L1-RSRP value and L1-RSRP values of the first set of L1-RSRP values being greater than a second threshold. The method may comprise, based on a difference between the first L1-RSRP value and the second L1-RSRP value being greater than a second threshold, sending a request for a CSI report. The method may comprise, based on a difference between the first L1-RSRP value and the second L1-RSRP value being greater than a second threshold, sending an indication of the difference between the first L1-RSRP value and the second L1-RSRP value. The method may comprise receiving configuration information comprising at least one of a synchronization signal / physical broadcast channel block (SSB) resource set, a transmission configuration indicator (TCI) state, a first CSI-RS resource set wherein each CSI-RS is associated with a TCI state, a reference RS, a second CSI-RS resource set, the first threshold, or a second threshold. Determining the first set of L1-RSRP values may comprise determining a difference between a highest L1-RSRP value of a CSI-RS resource of the CSI-RS resource set configured as a quasi co-location (QCL) type reference signal RS and a lowest L1-RSRP value of a CSI-RS resource of the CSI-RS resource set configured as a QCL type RS. Determining the first set of L1-RSRP values may comprise determining a difference between a highest L1-RSRP value of a CSI-RS of the CSI-RS resource set configured as a quasi co-location (QCL) type RS and at least one other L1-RSRP value of a CSI-RS of the CSI-RS resource set configured as a QCL type RS.

[0029] At least one example non-transitory computer-readable storage medium may comprise executable instructions for configuring at least one processor to determine, monitor, and / or maintain beams. The executable instructions may configure at least one processor to measure a plurality of channel state information (CSI) reference signals (RSs) of a first CSI-RS resource set using a first receive (Rx) beam to determine a first set of layer-1 (L1) reference signal received power (RSRP) values for each CSI-RS resource of the first CSI-RS resource set. The executable instructions may configure at least one processor to determine a L1-RSRP difference of a first CSI-RS resource of the first CSI-RS resource set based on the L1-RSRP values of the CSI-RS set. The executable 7   instructions may configure at least one processor to, based on the determined L1-RSRP difference being greater than a first threshold, send a CSI-RS resource indicator (CRI) comprising an indication of the CSI-RS resource of the first CSI-RS resource set having an L1-RSRP value resulting in the L1-RSRP difference being greater than the first threshold; and send a request for at least one CSI-RS resource of a second CSI-RS resource set. The executable instructions may configure at least one processor to measure a CSI-RS of the at least one CSI-RS resource of the second CSI-RS resource set to determine a second Rx beam and a second L1-RSRP value associated with the first CSI-RS resource of the first CSI-RS resource set. The executable instructions may configure at least one processor to, based on the first L1-RSRP value and the second L1-RSRP value, determine the second Rx beam. The executable instructions may configure at least one processor to receive one or more synchronization signal / physical broadcast channel blocks (SSBs) of an SSB resource set and determine the first Rx beam based on a search of each SSB of the SSB resource set. The second Rx beam may be determined based on CSI-RSs associated with the SSB resource set. The L1-RSRP difference of the first CSI-RS resource may be between an L1-RSRP of an SSB of the SSB resource set and a respective measured L1-RSRP value. The executable instructions may configure at least one processor to send a request for all CSI-RSs of the second CSI-RS resource set, use a plurality of Rx beams to measure CSI-RSs of the second CSI-RS resource set, and determine the second Rx beam based on measuring the CSI-RSs of the second CSI-RS resource set, wherein the second Rx beam is associated with an Rx beam of the plurality of Rx beams having a highest RSRP value. The executable instructions may configure at least one processor to send a request for all CSI-RSs of the second CSI-RS resource set based on an average difference of the second L1-RSRP value and L1-RSRP values of the first set of L1-RSRP values being greater than a second threshold. The executable instructions may configure at least one processor to, based on a difference between the first L1-RSRP value and the second L1-RSRP value being greater than a second threshold, send a request for a CSI report. The executable instructions may configure at least one processor to, based on a difference between the first L1-RSRP value and the second L1-RSRP value being greater than a second threshold, send an indication of the difference between the first L1-RSRP value and the second L1-RSRP value. The executable instructions may configure at least one processor to receive configuration information comprising at least one of a synchronization signal / physical broadcast channel block (SSB) resource set, a transmission configuration indicator (TCI) state, a first CSI-RS resource set wherein each CSI-RS is associated with a TCI state, a reference RS, a second CSI-RS resource set, the first threshold, or a second threshold. Determining the first set of L1-RSRP values may comprise determining a difference between a highest L1-RSRP value of a CSI-RS resource of the CSI-RS resource set configured as a quasi co-location (QCL) type reference signal RS and a lowest L1-RSRP value of a CSI-RS resource of the CSI-RS resource set configured as a QCL type RS. Determining the first set of L1-RSRP values may comprise determining a difference between a highest L1-RSRP value of a CSI-RS of the CSI-RS resource set configured as a quasi co-location (QCL) type RS and at least one other L1-RSRP value of a CSI-RS of the CSI-RS resource set configured as a QCL type RS. 8   BRIEF DESCRIPTION OF THE DRAWINGS

[0030] A more detailed understanding may be had from the detailed description below in conjunction with drawings appended hereto.

[0031] FIG.1A is an example system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0032] FIG.1B is an example system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0033] FIG.1C is an example system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0034] FIG.1D is an example system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0035] FIG.2 depicts an example Rx beam of an SSB that is quasi co-location (QCL) related with a channel state information – reference signal (CSI-RS).

[0036] FIG.3 depicts an example Rx beam of a previous beam reference signal (RS) that is QCL related with a newer beam RS. EXAMPLE NETWORKS FOR IMPLEMENTATION OF THE INVENTION

[0037] FIG.1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique- word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0038] As shown in FIG.1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 9   102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or a “STA”, may be configured to transmit and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE. Further, any description herein that is described with reference to a UE may be equally applicable to a WTRU (or vice versa). For example, a WTRU may be configured to perform any of the processes or procedures described herein as being performed by a UE (or vice versa).

[0039] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a next generation Node B (gNB), a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0040] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions. 10

[0041] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0042] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High- Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0043] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0044] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access , which may establish the air interface 116 using New Radio (NR).

[0045] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., a eNB and a gNB).

[0046] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA20001X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0047] The base station 114b in FIG.1A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a 11   wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As shown in FIG.1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0048] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG.1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may be utilizing a NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0049] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0050] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi- mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG.1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0051] FIG.1B is a system diagram illustrating an example WTRU 102. As shown in FIG.1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, among others. It will be appreciated that the 12   WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0052] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG.1B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0053] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0054] Although the transmit / receive element 122 is depicted in FIG.1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0055] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0056] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 13   and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0057] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0058] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0059] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0060] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit 139 to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the 14   WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0061] FIG.1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0062] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0063] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, and the like. As shown in FIG.1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0064] The CN 106 shown in FIG.1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0065] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0066] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like. 15

[0067] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0068] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0069] Although the WTRU is described in FIGS.1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0070] In representative embodiments, the other network 112 may be a WLAN.

[0071] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad-hoc” mode of communication.

[0072] When using the 802.11ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in in 802.11 16   systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0073] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0074] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0075] Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. The channel operating bandwidths, and carriers, are reduced in 802.11af and 802.11ah relative to those used in 802.11n, and 802.11ac. 802.11af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support Meter Type Control / Machine-Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0076] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), 17   transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0077] In the United States, the available frequency bands, which may be used by 802.11ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah is 6 MHz to 26 MHz depending on the country code.

[0078] FIG.1D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0079] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0080] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0081] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode- Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may 18   communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0082] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG.1D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0083] The CN 115 shown in FIG.1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0084] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP (third generation partnership project) access technologies such as WiFi.

[0085] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating WTRU IP address, managing 19   PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0086] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0087] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0088] In view of Figs.1A-1D, and the corresponding description of Figs.1A-1D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0089] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may perform testing using over-the-air wireless communications.

[0090] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation 20   devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0091] Described herein are methods and apparatuses for selecting, determining, and supporting auxiliary Rx (receive) beams. Terminology used herein is described below. Hereinafter, ‘a’ and ‘an’ and similar phrases are to be interpreted as ‘one or more’ and ‘at least one’. Similarly, any term which ends with the suffix ‘(s)’ is to be interpreted as ‘one or more’ and ‘at least one’. The term ‘may’ is to be interpreted as ‘may, for example’.

[0092] Artificial intelligence (AI) may be broadly defined as the behavior exhibited by machines. Such behavior may e.g., mimic cognitive functions to sense, reason, adapt and act. Machine learning (ML) may refer to types of algorithms that solve a problem based on learning through experience (‘data’), without explicitly being programmed (‘configuring set of rules’). Machine learning may be considered as a subset of AI. Different machine learning paradigms may be envisioned based on the nature of data or feedback available to the learning algorithm. For example, a supervised learning approach may involve learning a function that maps input to an output based on labeled training example, wherein each training example may be a pair consisting of input and the corresponding output. For example, unsupervised learning approach may involve detecting patterns in the data with no pre-existing labels. For example, reinforcement learning approach may involve performing sequence of actions in an environment to maximize the cumulative reward. In some solutions, it is possible to apply machine learning algorithms using a combination or interpolation of the above-mentioned approaches. For example, semi-supervised learning approach may use a combination of a small amount of labeled data with a large amount of unlabeled data during training. In this regard semi-supervised learning falls between unsupervised learning (with no labeled training data) and supervised learning (with only labeled training data).

[0093] Deep learning (DL) may refer to classes of machine learning algorithms that employ artificial neural networks (e.g., deep neural nets (DNNs)) which were loosely inspired from biological systems. Deep Neural Networks (DNNs) are a special class of machine learning models inspired by the human brain wherein the input is linearly transformed and pass-through non-linear activation function multiple times. DNNs typically comprise multiple layers where each layer comprises linear transformation and a given non-linear activation functions. DNNs can be trained using the training data via back-propagation algorithm. Recently, DNNs have shown state-of-the-art performance in variety of domains, e.g., speech, vision, natural language etc. and for various machine learning settings supervised, un-supervised, and semi-supervised. The term AIML (AI and / or ML) based methods / processing may refer to realization of behaviors and / or conformance to requirements by learning based on data, without explicit configuration of sequence of steps of actions. Such methods may enable learning complex behaviors which might be difficult to specify and / or implement when using legacy methods. 21

[0094] Regarding the term beam, a WTRU may transmit or receive a physical channel or reference signal according to at least one spatial domain filter. The term “beam” may be used to refer to a spatial domain filter.

[0095] A WTRU may transmit a physical channel or signal using the same spatial domain filter as the spatial domain filter used for receiving a reference signal (RS), such as a channel state information – reference signal (CSI- RS) or a synchronization signal (SS) block. A WTRU transmission may be referred to as “target”, and the received RS or SS block may be referred to as “reference” or “source”. In such case, the WTRU may be said to transmit the target physical channel or signal according to a spatial relation with a reference to such RS or SS block.

[0096] A WTRU may transmit a first physical channel or signal according to the same spatial domain filter as the spatial domain filter used for transmitting a second physical channel or signal. The first and second transmissions may be referred to as “target” and “reference” (or “source”), respectively. In such case, the WTRU may be said to transmit the first (target) physical channel or signal according to a spatial relation with a reference to the second (reference) physical channel or signal.

[0097] A spatial relation may be implicit, configured by radio resource control (RRC), or signaled by a medium access control (MAC) control element (CE) or downlink control information (DCI). For example, a WTRU may implicitly transmit a physical uplink shared control channel (PUSCH) and demodulation reference signal (DM-RS) of a PUSCH according to the same spatial domain filter as a sounding reference signal (SRS) indicated by an SRI (SRS resource indicator) indicated in DCI, or configured by RRC. A spatial relation may be configured by RRC for an SRI or signaled by a MAC-CE for a physical uplink control channel (PUCCH). Such spatial relation may also be referred to as a “beam indication”.

[0098] A WTRU may receive a first (target) downlink channel or signal according to the same spatial domain filter or spatial reception parameter as a second (reference) downlink channel or signal. For example, such association may exist between a physical channel such as physical downlink control channel (PDCCH) or physical downlink shared channel (PDSCH) and its respective demodulation reference signal (DM-RS). When the first and second signals are reference signals, such association may exist when the WTRU is configured with a quasi-colocation (QCL) assumption type D between corresponding antenna ports. Such association may be configured as a transmission configuration indicator (TCI) state. A WTRU may be indicated an association between a CSI-RS or SS block and a DM-RS by an index to a set of TCI states configured by RRC and / or signaled by MAC CE. Such indication may also be referred to as a “beam indication”.

[0099] Hereafter, a TRP (e.g., transmission and reception point) may be interchangeably used with one or more of TP (transmission point), RP (reception point), RRH (radio remote head), DA (distributed antenna), BS (base station), a sector (of a BS), and a cell (e.g., a geographical cell area served by a BS), but still consistent with the 22   herein disclosure. Hereafter, Multi-TRP may be interchangeably used with one or more of MTRP, M-TRP, and multiple TRPs, but still consistent with the herein disclosure.

[0100] A WTRU may report a subset of channel state information (CSI) components, where CSI components may correspond to at least a CSI-RS resource indicator (CRI), a SSB resource indicator (SSBRI), an indication of a panel used for reception at the WTRU (such as a panel identity or group identity), measurements such as L1-RSRP, L1- SINR (signal interference plus noise ratio) taken from SSB or CSI-RS (e.g. cri-RSRP, cri-SINR, ssb-Index-RSRP, ssb-Index-SINR), and other channel state information such as at least rank indicator (RI), channel quality indicator (CQI), precoding matrix indicator (PMI), Layer Index (LI), and / or the like.

[0101] Regarding the term SSB, a WTRU may receive a synchronization signal / physical broadcast channel (SS / PBCH) block. The SS / PBCH block (SSB) may include a primary synchronization signal (PSS), secondary synchronization signal (SSS), and physical broadcast channel (PBCH). The WTRU may monitor, receive, or attempt to decode an SSB during initial access, initial synchronization, radio link monitoring (RLM), cell search, cell switching, and so forth.

[0102] A WTRU may measure and report CSI, wherein the CSI for each connection mode may include or be configured with one or more of following. For example, a CSI Report Configuration may include one or more of a CSI report quantity, e.g., Channel Quality Indicator (CQI), a Rank Indicator (RI), a Precoding Matrix Indicator (PMI), a CSI-RS Resource Indicator (CRI), a Layer Indicator (LI), a CSI report type, e.g., aperiodic, semi persistent, periodic, a CSI report codebook configuration, e.g., Type I, Type II, Type II port selection, etc., a CSI report frequency, or any appropriate combination thereof.

[0103] A CSI-RS Resource Set may include one or more of the following CSI Resource settings. For example, the a CSI-RS Resource Set may include one or more a non-zero power (NZP)-CSI-RS Resource for channel measurement, a NZP-CSI-RS Resource for interference measurement, a CSI-IM Resource for interference measurement, a NZP CSI-RS Resources, or any appropriate combination thereof. The NZP CSI-RS Resources may include one or more of a NZP CSI-RS Resource ID, a Periodicity and offset, QCL Info and TCI-state, Resource mapping, e.g., number of ports, density, code division multiplexing (CDM) type, etc., or any appropriated combination thereof.

[0104] A WTRU may indicate, determine, or be configured with one or more reference signals. The WTRU may monitor, receive, and measure one or more parameters based on the respective reference signals. For example, one or more of the following may apply. The following parameters are non-limiting examples of the parameters that may be included in reference signal(s) measurements. One or more of these parameters may be included. Other parameters may be included. 23

[0105] Parameters may include SS-RSRP. SS reference signal received power (SS-RSRP) may be measured based on the synchronization signals (e.g., demodulation reference signal (DMRS) in PBCH or SSS). It may be defined as the linear average over the power contribution of the resource elements (RE) that carry the respective synchronization signal. In measuring the RSRP, power scaling for the reference signals may be required. In case SS- RSRP is used for L1-RSRP, the measurement may be accomplished based on CSI reference signals in addition to the synchronization signals.

[0106] Parameters may include CSI-RSRP. CSI-RSRP may be measured based on the linear average over the power contribution of the resource elements (RE) that carry the respective CSI-RS. The CSI-RSRP measurement may be configured within measurement resources for the configured CSI-RS occasions.

[0107] Parameters may include SS-SINR. SS signal-to-noise and interference ration (SS-SINR) may be measured based on the synchronization signals (e.g., DMRS in PBCH or SSS). It may be defined as the linear average over the power contribution of the resource elements (RE) that carry the respective synchronization signal divided by the linear average of the noise and interference power contribution. In case SS-SINR is used for L1-SINR, the noise and interference power measurement may be accomplished based on resources configured by higher layers.

[0108] Parameters may include CSI-SINR. CSI-SINR may be measured based on the linear average over the power contribution of the resource elements (RE) that carry the respective CSI-RS divided by the linear average of the noise and interference power contribution. In case CSI-SINR is used for L1-SINR, the noise and interference power measurement may be accomplished based on resources configured by higher layers. Otherwise, the noise and interference power may be measured based on the resources that carry the respective CSI-RS.

[0109] Parameters may include RSSI. Received signal strength indicator (RSSI) may be measured based on the average of the total power contribution in configured OFDM symbols and bandwidth. The power contribution may be received from different resources (e.g., co-channel serving and non-serving cells, adjacent channel interference, thermal noise, and so forth)

[0110] Parameters may include CLI-RSSI. Cross-Layer interference received signal strength indicator (CLI-RSSI) may be measured based on the average of the total power contribution in configured OFDM symbols of the configured time and frequency resources. The power contribution may be received from different resources (e.g., cross-layer interference, co-channel serving and non-serving cells, adjacent channel interference, thermal noise, and so forth)

[0111] Parameters may include SRS-RSRP. Sounding reference signals RSRP (SRS-RSRP) may be measured based on the linear average over the power contribution of the resource elements (RE) that carry the respective SRS. 24

[0112] A CSI report configuration (e.g., CSI-ReportConfigs) may be associated with a single band width part (BWP) (e.g., indicated by BWP-Id – BWP identifier), wherein one or more of the following parameters are configured: CSI-RS resources and / or CSI-RS resource sets for channel and interference measurement, CSI-RS report configuration type including the periodic, semi-persistent, and aperiodic, CSI-RS transmission periodicity for periodic and semi-persistent CSI reports, CSI-RS transmission slot offset for periodic, semi-persistent and aperiodic CSI reports, CSI-RS transmission slot offset list for semi-persistent and aperiodic CSI reports, time restrictions for channel and interference measurements, report frequency band configuration (wideband / subband CQI, PMI (precoding matrix indicator), and so forth), thresholds and modes of calculations for the reporting quantities (CQI, RSRP, SINR, LI, RI, etc.), codebook configuration, group based beam reporting, CQI table, Subband size, Non-PMI port indication, Port Index, or the like, or any appropriate combination thereof.

[0113] A CSI-RS Resource Set (e.g., NZP-CSI-RS-ResourceSet) may include one or more of CSI-RS resources (e.g., NZP-CSI-RS-Resource and CSI-ResourceConfig), wherein a WTRU may be configured with one or more of the following in a CSI-RS Resource: CSI-RS periodicity and slot offset for periodic and semi-persistent CSI-RS Resources, CSI-RS resource mapping to define the number of CSI-RS ports, density, CDM-type, OFDM symbol, and subcarrier occupancy, the bandwidth part to which the configured CSI-RS is allocated, the reference to the TCI-State including the QCL source RS(s) and the corresponding QCL type(s), or any appropriate combination thereof.

[0114] One or more of following configurations may be used for RS resource set. For example, a WTRU may be configured with one or more RS resource sets. The RS resource set configuration may include one or more of an RS resource set ID, one or more RS resources for the RS resource set, repetition (e.g., on or off). aperiodic triggering offset (e.g., one of 0-6 slots), tracking reference signal (TRS) info (e.g., true or not), or any appropriate combination thereof.

[0115] Regarding RS resource configuration, one or more of following configurations may be used for RS resource. A WTRU may be configured with one or more RS resources. The RS resource configuration may include one or more of an RS resource ID, resource mapping (e.g., Res (resource elements) in a PRB (physical resource block)), power control offset (e.g., one value of -8, …, 15), power control offset with SS (e.g., -3 dB, 0 dB, 3 dB, 6 dB), scrambling ID, periodicity and offset, QCL information (e.g., based on a TCI state), or any appropriate combination thereof.

[0116] In the following, a property of a grant or assignment may comprise at least one of the following. For example, a property of a grant or assignment may comprise a frequency allocation, an aspect of time allocation, such as a duration, a priority, a modulation and coding scheme, a transport block size, a number of spatial layers, a number of transports blocks, a TCI state, CRI or SRI, a number of repetitions, whether the repetition scheme is Type A or Type B, whether the grant is a configured grant type 1, type 2 or a dynamic grant, whether the assignment is a dynamic assignment or a semi-persistent scheduling (configured) assignment, a configured grant index or a semi- 25   persistent assignment index, a periodicity of a configured grant or assignment, a channel access priority class (CAPC), any parameter provided in a DCI, by MAC or by RRC for the scheduling the grant or assignment, or any appropriate combination thereof.

[0117] In the following, an indication by DCI may comprise at least one of the following. For example an indication by DCI may comprise an explicit indication by a DCI field or by a radio network temporary identifier (RNTI) used to mask a cyclic redundancy check (CRC) of the PDCCH, an implicit indication by a property such as DCI format, DCI size, Coreset or search space, Aggregation Level, first resource element of the received DCI (e.g., index of first Control Channel Element), where the mapping between the property and the value may be signaled by RRC or MAC, or any appropriate combination thereof.

[0118] Consistent with the herein disclosure, RS may be interchangeably used with one or more of RS resource, RS resource set, RS port and RS port group, but still consistent with the herein disclosure. RS may be interchangeably used with one or more of SSB, CSI-RS, SRS, DM-RS, TRS, PRS, and PTRS, but still consistent with the herein disclosure. A reference signal may be interchangeably used with one or more of following: Sounding reference signal (SRS), Channel state information – reference signal (CSI-RS), Demodulation reference signal (DM- RS), Phase tracking reference signal (PT-RS), or Synchronization signal block (SSB).

[0119] Consistent with the herein disclosure, a channel may be interchangeably used with one or more of PDCCH, PDSCH, Physical uplink control channel (PUCCH), Physical uplink shared channel (PUSCH), Physical random access channel (PRACH), or the like.

[0120] A key performance indicator (KPI) may refer to, but not limited to, one or more of the following. For example, a KPI may refer to signal quality (e.g., L1-RSRP, SINR, CQI, RSSI, RSRQ (reference signal received quality)), prediction performance (e.g., Percentage of the Top-1 genie-aided (i.e., best) beam is one of the Top-K predicted beams), link quality (e.g., throughput, block error rate (BLER)), data distribution (e.g., mean and / or variance of measured and / or predicted beam measurements), or RSRP (e.g., L1-RSRP) difference (i.e., the difference between measured and predicted RSRP of a beam).

[0121] Hereafter, a signal, channel, and message (e.g., as in DL or UL signal, channel, and message) may be used interchangeably, but still consistent with the herein disclosure. Hereafter, an RS resource set may be interchangeably used with an RS resource and a beam group, but still consistent with the herein disclosure. Hereafter, beam reporting may be interchangeably used with CSI measurement, CSI reporting and beam measurement, but still consistent with the herein disclosure. Hereafter, the herein examples for beam resources prediction may be used for beam resources belonging to a single or multiple cells as well as single or multiple TRPs, and still consistent with the herein disclosure. Hereafter, CSI reporting may be interchangeably used with CSI measurement, beam reporting and beam measurement, but still consistent with the herein disclosure. Hereafter, a 26   RS resource set may be interchangeably used with a beam group, but still consistent with the herein disclosure. Hereafter, a Set B may be interchangeably used with a set of - RS resource sets, beams, beam-pairs, beam RS resources, RS resources and a beam pattern. Hereafter, a Set A may be interchangeably used with a set of - RS resource sets, beams, beam-pairs, beam RS resources, RS resources, and a beam pattern.

[0122] FIG.2 is an example depiction of an example Rx beam of an SSB (e.g., wide beam) which is QCL-related with a CSI-RS. FIG.3 is an example depiction of an Rx beam of an old (e.g., previous, received in the past) beam RS (e.g., SSB or CSI-RS) QCL-related (e.g., QCL-TypeD) with a newer (e.g., current) beam RS. An Auxiliary Rx (receive) beam may refer to an Rx beam determined / selected in addition to Rx beams determined / selected / searched through conventional methods (e.g., exhaustive beam search). Examples of auxiliary Rx beams (e.g., 202 in FIG.2, 302 in FIG.3) are illustrated by FIG.2 and FIG.3.

[0123] Determining, monitoring, and maintaining auxiliary Rx beams based on SSBs may be summarized as follows. A WTRU (102) may receive a configuration of a SSB resource set, TCI states, a first CSI-RS resource set where each CSI-RS is associated with a TCI state, wherein the TCI state may include a SSB as a new QCL Type (e.g., wide beam) reference RS, a second CSI-RS resource set (e.g., aperiodic) (e.g., where all CSI-RS resources are configured with repetition), a first threshold for L1-RSRP difference, a second threshold for a new CSI reporting, or any appropriate combination thereof.

[0124] The WTRU may receive / detect one or more SSBs of the SSB resource set and determines a first set of best Rx beams (e.g., through exhaustive beam search) for each SSB of the SSB resource set. The WTRU may measure a plurality of CSI-RSs of a CSI-RS resource set using an Rx beam to determine a first set of layer-1 (L1) reference signal received power (RSRP) values for each CSI-RS resource of the first CSI-RS resource set. The WTRU may measure the CSI-RSs of the first CSI-RS resource set using for each CSI-RS, the Rx beam of the first set of best Rx beams determined for the SSBs configured as QCL reference for the CSI-RS and may determine a first set of L1-RSRP values for each CSI-RS in the first CSI-RS resource set.

[0125] The WTRU may determine an L1-RSRP difference of a first CSI-RS resource of the first CSI-RS resource set based on the L1-RSRP values of the CSI-RS set. The L1-RSRP difference of the first CSI-RS resource may be between an L1-RSRP of an SSB of the SSB resource set and a respective measured L1-RSRP value. The WTRU may determine an L1-RSRP difference based on the measurement, such as, for example, (1) the L1-RSRP difference between L1-RSRPs of an SSB (e.g., highest RSRP SSB) and a CSI-RS (e.g., worst) which are QCL- related with the same SSB, (2) the L1-RSRP difference between L1-RSRPs of a CSI-RS (e.g., best) associated with an SSB (e.g., highest RSRP SSB) and one or more other CSI-RSs which are QCL-related with the same SSB, (3) other conditions and actions e.g., average L1-RSRP of CSI-RSs QCL-related with an SSB for triggering exhaustive Rx beam, e.g., a condition to turn on or off this procedure, or any appropriate combination thereof. 27

[0126] The WTRU may report the first set of L1-RSRP values of the first CSI-RS resource set. Based on the determined L1-RSRP difference being greater than a first threshold, the WTRU may send a CSI-RS resource indicator (CRI) comprising an indication of the CSI-RS resource of the first CSI-RS resource set having an L1-RSRP value resulting in the L1-RSRP difference being greater than the first threshold Based on the determined L1-RSRP difference being greater than the first threshold, the WTRU may send a request for at least one CSI-RS resource of a second CSI-RS resource set. If the determined L1-RSRP difference for a CSI-RS resource of the first set is greater than the first threshold, the WTRU may send a CRI indicating the CSI-RS resource of the first set whose L1-RSRP is greater than the first threshold and a request to the gNB requesting transmission of at least one CSI-RS in the second CSI-RS resource set (e.g., to determine a second best Rx beam for the indicated CSI-RS resource of the first set).

[0127] The WTRU may measure a CSI-RS of the at least one CSI-RS resource of the second CSI-RS resource set to determine a second Rx beam and a second L1-RSRP value associated with the first CSI-RS resource of the first CSI-RS resource set. Based on the first L1-RSRP value and the second L1-RSRP value, the WTRU may determine a second Rx beam. The WTRU may send a request for all CSI-RSs of the second CSI-RS resource set and may determine the second Rx beam based on a search of all the CSI-RSs of the second CSI-RS resource set. The WTRU may use a plurality of Rx beams to measure CSI-RSs of the second CSI-RS resource set. The WTRU may determine the second Rx beam based on measuring the CSI-RSs of the second CSI-RS resource set, wherein the second Rx beam is associated with an Rx beam of the plurality of Rx beams having a highest RSRP value. The WTRU may measure the at least one CSI-RS resource of the second CSI-RS resource set and may determine a second best Rx beam and a second L1-RSRP value (e.g., based on the second best Rx beam) for the indicated CSI- RS resource of the first set. If the second L1-RSRP value of the indicated CSI-RS resource of the first set satisfies a condition (e.g., a difference between the second L1-RSRP value and L1-RSRP value of the first set of L1-RSRP values (e.g., associated with the same CSI-RS resource) > the second threshold), the WTRU may send an indication to the gNB indicating a change (e.g., requesting a new CSI report and / or indicating the L1-RSRP difference). A WTRU may receive one or more SSBs of an SSB resource set and may determine Rx beams based on a search of each SSB of the SSB resource set. The WTRU may send a request for all CSI-RSs of the second CSI-RS resource set based on an average difference of the second L1-RSRP value and L1-RSRP values of the first set of L1-RSRP values being greater than a second threshold. Based on the L1-RSRP values (e.g., average difference of second L1- RSRP value and L1-RSRP values of the first set of L1-RSRP values), the WTRU may trigger exhaustive search (i.e., send a request to gNB for transmission of all the RSs of the second RS resource set) for determining a second set of best Rx beams of all CSI-RSs related to an SSB. 28

[0128] A more detailed description of determining, monitoring, and maintaining auxiliary Rx beams based on SSBs is provided below. Hereafter, quality may be interchangeably used with RSRP, RSRQ, SINR, L1-RSRP, L1- RSRQ, L1-SINR, CQI, hypothetical PDCCH BLER and others, but still consistent with this disclosure.

[0129] A WTRU may receive a configuration of one or more of first RS resource sets (e.g., SSB resource set) with one or more first RS resources, one or more TCI states, a second RS resource set (e.g., CSI-RS resource set) with one or more second RS resources, wherein each second RS may be associated with a TCI state of the one or more TCI states. The TCI state may include a first RS resource as a QCL reference signal for a QCL Type. The QCL Type may be a new QCL Type. The new QCL type may indicate that the first RS resource may use a wide beam which is covering a beam (e.g., narrow beam) used for the second RS resource. The QCL Type may be a QCL Type D. The configuration further may include a third RS resource set (e.g., aperiodic CSI-RS resource set) with one or more third RS resources. The third RS resource set may be configured for RX beam refinement (e.g., the third RS resource set is configured with Tx beam repetition and / or identical Tx beam). The configuration further may include a first threshold for identifying quality difference (e.g., L1-RSRP difference), and a second threshold for WTRU reporting (e.g., CSI reporting).

[0130] The WTRU may measure / detect the one or more first RS resources (e.g., SSBs) of the first RS resource set. Based on the measurement / detection, the WTRU may determine a best Rx beam (i.e., a spatial domain Rx filter) for each first RS resource of the first RS resource set.

[0131] The WTRU may measure the second RS resources of the second RS resource set. The second Rx beam may be based on CSI-RSs associated with the SSB resource set. The measurement may be based on a best Rx beam associated with a first RS resource with each second RS resource (e.g., configured as a QCL reference signal). Based on the measurement, the WTRU may determine one or more qualities (e.g., L1-RSRP) for each second RS resource or the second RS resource set. Based on the one or more qualities, one or more quality difference metrics may be determined. For example, one or more of the following may be used.

[0132] The quality difference (e.g., L1-RSRP difference) between a quality (e.g., L1-RSRPs) of a first RS resource (e.g., best SSB (e.g., with highest RSRP)) and a quality of a second RS resource (e.g., worst CSI-RS (e.g., with lowest RSRP)) which are QCL-related with the first RS resource may be used.

[0133] The quality difference (e.g., L1-RSRP difference) between a quality (e.g., L1-RSRPs) of a second RS resource (e.g., best CSI-RS (e.g., with highest RSRP)) which is QCL-related a first RS resource (e.g., best SSB (e.g., with highest RSRP)) and qualities of other one or more second RS resources (e.g., one or more of neighboring CSI- RS resources, all other CSI-RS resources except the best CSI-RS resource and a worst CSI-RS resource (e.g., with lowest RSRP)) which are QCL-related with the first RS resource may be used. For all other CSI-RS resources, highest / lowest quality difference may be considered. 29

[0134] The quality difference (e.g., L1-RSRP difference) between a quality (e.g., L1-RSRPs) of a second RS resource (e.g., best CSI-RS (e.g., with highest RSRP)) which is QCL-related a first RS resource (e.g., best SSB (e.g., with highest RSRP)) and a quality of all second RS resources which are QCL-related with the first RS resource may be used. The quality of all second RS resources may be determined as a highest / lowest / average of all measured qualities of all second RS resources.

[0135] The quality difference (e.g., L1-RSRP difference) between a quality (e.g., L1-RSRPs) of a first RS resource (e.g., best SSB (e.g., with highest RSRP)) and a quality of another first RS resource (e.g., second best / worst / neighboring SSB (e.g., with lowest RSRP)) may be used.

[0136] The WTRU may determine a mode of operation based on the determined one or more qualities and / or quality difference metrics. For example, if the one or more qualities and / or quality difference metrics are larger than the first threshold, the WTRU may determine a first mode of operation (e.g., additional Rx beam refinement). If the one or more qualities and / or quality difference metrics smaller than (or equal to) the first threshold, the WTRU may determine a second mode of operation (e.g., no additional Rx beam refinement).

[0137] The WTRU may indicate the determined mode of operation. The indication may be based on one or more of the following.

[0138] The indication may be based on an explicit indication. The WTRU may indicate a mode of operation (e.g., 1: the first mode and 0: the second mode). For example, the mode of operation may be used for determining CSI reporting mode.

[0139] The indication may be based on an implicit indication. For example, the WTRU may indicate a mode of operation implicitly. One or more of the following may be used.

[0140] The indication may be based on a quality / quality difference. For example, if the indicated quality / quality difference is larger than the second threshold, the WTRU may indicate the first mode of operation. If the indicated quality / quality difference is less than (or equal to) the second threshold, the WTRU may indicate the second mode of operation. The second threshold may be identical with the first threshold.

[0141] The indication may be based on one or more candidate beams (e.g., for additional Rx beam refinement). For example, the indication may be based on the indicated one or more candidate beams (e.g., via one or more CRIs and / or SSBRIs). For example, if the WTRU indicates the one or more candidate beams, the WTRU may indicate the first mode of operation. If the WTRU does not indicate the one or more beams, the WTRU may indicate the second mode of operation.

[0142] The indication may be based on a request of one or more RS resources (e.g., for additional Rx beam refinement. For example, if the WTRU requests the one or more RS resources, the WTRU may indicate the first 30   mode of operation. If the WTRU does not request the one or more RS resources, the WTRU may indicate the second mode of operation.

[0143] Based on the WTRU indication, the WTRU may receive one or more gNB confirmations. The confirmation may be based on DL channels (e.g., PDCCH, PDSCH and etc.) and / or DL signals (e.g., DMRS, PT-RS, CSI-RS and etc.). For example, the WTRU may monitor candidate resources (e.g., SS / CORESET for PDCCH) after the indication. If the WTRU detects the candidate resources or receives a gNB confirmation, the WTRU may use the indicated mode of operation. If the WTRU does not detect the candidate resources or receives a gNB NACK, the WTRU may not use the indicated mode of operation and / or use the original mode of operation.

[0144] Based on the WTRU indication and / or the gNB confirmation, the WTRU may trigger the procedure for additional Rx beam refinement. For example, the WTRU may receive the third RS resource set. The slot offset and / or periodicity may be defined from the WTRU indication and / or the gNB confirmation. The third RS resource set may be configured with repetition with a same beam (e.g., one or more indicated candidate beams for additional Rx beam refinement). Based on the measurement of third RS resource set, the WTRU may determine a best spatial domain filter (e.g., a best Rx beam). For example, the WTRU may measure a first RS resource of the third RS resource set with a first Rx beam, a second RS resource of the third RS resource set with a second Rx beam and so forth. Based on the measurements, the WTRU may determine a Rx beam with best quality (e.g., RSRP). Based on the determined Rx beam, the WTRU may receive one or more DL channels and signals.

[0145] Determining, monitoring, and maintaining auxiliary Rx beams based on time may be summarized as follows. A WTRU may receive a configuration of TCI-states, a first RS resource set where each RS is associated with a TCI state a second RS resource set (e.g., aperiodic) (e.g., where all RS resources are configured with repetition), a time threshold RX_TIMER_MAX, a time offset T_MINUS, a threshold for L1-RSRP difference, or any appropriate combination thereof.

[0146] The WTRU may maintain an RX_TIMER counting the time (e.g., symbols / slots / ms) from the previous instance of Rx beams exhaustive search-based determination. If RX_TIMER < RX_TIMER_MAX, the WTRU may measure RSs of the first RS resource set using the TCI-states (e.g., using a first set of Rx beams determined from the configured TCI-states) and determines a first set of L1-RSRP values for each RS of the first RS resource set.

[0147] If RX_TIMER < RX_TIMER_MAX, the WTRU may report to the gNB the measured first set of L1-RSRP values, and sends a CRI (e.g., CRI of the CSI-RS resource with the highest L1-RSRP) and a request to the gNB requesting transmission of at least one RS in the second RS resource set (e.g., to determine a second Rx beam for the RS resource associated with the indicated CRI). The WTRU may measure the at least one RS of the second RS resource set and determines a second best Rx beams and a second L1-RSRP value of the RS resource associated with the indicated CRI based on the determined second best Rx beam. Based on the first and second L1-RSRP 31   values of the RS resource associated with the indicated CRI (e.g., if the difference between the second L1-RSRP value and the first L1-RSRP value of the RS resource associated with the indicated CRI, is greater than the threshold), the WTRU may reset the RX_TIMER and may trigger reset stage. The WTRU may report the second L1- RSRP value and RX_TIMER reset (e.g., as part of next CSI report).

[0148] Based on the first and second L1-RSRP values of the RS resource associated with the indicated CRI (e.g., if the difference between the second L1-RSRP value and the first L1-RSRP value of the RS resource associated with the indicated CRI, is less than or equal to the threshold), the WTRU may subtract the time offset value, T_MINUS, from the RX_TIMER. The WTRU may report second L1-RSRP value and RX_TIMER value (e.g., as part of next CSI report).

[0149] Regarding the reset stage, if RX_TIMER >= RX_TIMER_MAX OR reset is triggered, the WTRU may send a request to the gNB requesting transmission of all RSs of the second RS resource set (e.g., for new round of Rx beam training). (E.g., implicit request via reporting some measurement or parameter through CSI-Report e.g., RX_TIMER reset). The WTRU may measures the transmitted resources of the second RS resource set and determines a second set of best Rx beams (e.g., one for each RS) and a second set of L1-RSRP values of the RSs based on the second set of best Rx beams. The WTRU may report to gNB the measured second set of L1-RSRP values (e.g., via sending a request for a resource for CSI-Report).

[0150] A more detailed description of determining, monitoring, and maintaining auxiliary Rx beams based on time is provided below. A WTRU may receive configurations or be configured to receive one or more reference signals (RS). The RS may be one or more SS / PBCH block (SSB), CSI-RS, PT-RS, and so forth. The WTRU may receive one or more CSI report configurations (e.g., CSI-ReportConfig). A CSI report configuration may include a CSI report quantity that may indicate the CSI parameters that may be required to be measured, estimated, derived, and / or reported. In an example, the CSI report quantity could be one or more of the Channel Quality Indicator (CQI), Rank Indicator (RI), Precoding Matrix Indicator (PMI), CSI-RS Resource Indicator (CRI), Layer Indicator (LI), Signal-to- Noise and Interference Ratio (SINR), Reference Signal Received Power (RSRP), and so forth.

[0151] The CSI report configuration may be associated with one or more CSI resource settings (e.g., CSI- ResourceConfig) for channel and / or interference measurement. A resource setting may include a list of CSI Resource Sets, where the list may comprise of references to one or more CSI-RS resource sets and / or SSB sets.

[0152] The WTRU may perform measurements on one or more CSI-RS resources and derive one or more CSI parameters. For example, during the beam selection, the WTRU may measure and derive received power and report (e.g., RSRP) for one or more beam resources (e.g., up to four highest RSRP). In another example, the WTRU may determine a CRI (e.g., based on a priority such as CQI, RSRP, and so forth) from the supported and / or configured set of CRI values and report CRI along with one or more CSI parameters for the determined CRI. As such, the 32   WTRU may measure and derive one or more CSI parameters for the determined CRI, conditioned on the reported CRI.

[0153] The WTRU may receive one or more reference signals and / or channels that may be transmitted (e.g., from a gNB) through different TCI-states, spatial filters and / or directions within a configured time and frequency resources. The WTRU may use and / or adjust its spatial receive filters to match the spatial filters and / or TCI-states to receive signals and / or channels from corresponding transmitters. As such, the WTRU may determine the beam direction for the received signals and / or channels based on the receiving spatial filter and / or TCI-states.

[0154] In an of example of determining, monitoring, and maintaining auxiliary Rx beams based on time, a WTRU may receive configuration information, where the configuration may include one or more of the following. The configuration may include one or more TCI states. For example, the WTRU may receive configuration information on a set of one or more TCI states. The configuration may include a first RS resource set: For example, the WTRU may be configured with a first RS resource set including one or more first RS resources. In an example, the first RS resources may include one or more SSB resources. The WTRU may be configured with SSB indexes that correspond to the configured SSB resources. In another example, at least one of the first RS resources may be associated with a configured TCI state.

[0155] The configuration may include a second RS resource set. For example, the WTRU may be configured with a second RS resource set including one or more second RS resources. In an example, the second RS resource set may include one or more CSI-RS resource sets, where each CSI-RS resource sets may include one or more CSI-RS resources. The WTRU may be configured with second RS resources including at least the reference signals, RS resource indexes (e.g., CRI), time and frequency resources, repetition, report type (e.g., aperiodic), and so forth. The second RS resources may be configured with aperiodic time pattern and number of repetitions that is more than one. The second RS resources may be transmitted (e.g., sweeping) from a transmitter (e.g., a gNB) through different TCI- states, spatial filters and / or directions within a configured time and frequency resources. In an example, the WTRU may use the second RS resources for Rx beam prediction AIML training and / or Rx beam refinement. In an example, the WTRU may use the second RS resources for Rx beam refinement based on exhaustive Rx beam search. The second RS resources may be associated with a TCI state from the one or more configured TCI states, where the configured TCI state may be associated with a first RS resource as the QCL reference signal.

[0156] The configuration may include a timer and / or counter threshold (e.g., RX_TIMER_MAX). For example, the WTRU may be configured with one or more maximum values for a timer and / or a counter, where the WTRU may compare the value of the timer and / or counter with the configured maximum threshold. In an example, the value of the configured timer may be in time units (e.g., ms, us, etc.), or based on number of time instances (e.g., symbols, slots, frames, subframes, etc.). 33

[0157] The configuration may include a time offset (e.g., T_MINUS). For example, the WTRU may be (pre)configured with one or more time offset values, where the WTRU may use the configured time offset values to adjust, update, reconfigure, or change the value of a timer.

[0158] The configuration may include thresholds for difference in measured parameters. For example, the WTRU may be (pre)configured with one or more threshold values for the differential values and / or the difference value for one or more measured parameters (e.g., L1-RSRP difference). For example, the WTRU may calculate and / or determine the difference value for a measured parameter that may be measured in different scenarios. For example, the WTRU may calculate and / or determine the difference value for a measured parameter that may be measured in a first and a second time instances. For example, the WTRU may calculate and / or determine the difference value between a newly measured value for a parameter (e.g., that was measured recently) with an older value for the parameter (e.g., that was measured previously). In another example, the WTRU may determine the difference between a measured parameter with a reference parameter. The WTRU may compare the determined and / or calculated difference value with the configured threshold for the difference in measured parameters.

[0159] A WTRU may initiate and / or reset a timer (e.g., RX_TIMER) at the time when the last exhaustive search- based Rx beam determination was performed. For example, the WTRU may perform the procedure regarding exhaustive search-based Rx beam determination to determine a first (best) Rx beam. Upon completion of the procedure regarding exhaustive search-based Rx beam determination, the WTRU may initiate the timer (e.g., RX_TIMER). In an example, the WTRU may use the timer to measure the time lapse and / or time duration based on the time units (e.g., ms, us, etc.), the number of symbols, slots, subframes, and so forth.

[0160] A WTRU may compare a timer value with one or more timer thresholds, where the WTRU may determine the mode of operation based on the comparison results. In an example, the WTRU may compare the timer value (e.g., RX_TIMER) with a timer threshold (e.g., RX_TIMER_MAX). The WTRU may determine the mode of operation based on whether the timer value is smaller or larger than the timer threshold. The WTRU may determine the mode of operation between a first and a second mode of operation. In an example, the first mode of operation may be based on Rx beam monitoring and maintaining. For example, the WTRU may monitor and maintain auxiliary Rx beams. In another example, the second mode of operation may be based on Rx beam refinement and selection based on exhaustive search-based Rx beam determination.

[0161] A WTRU may select a first mode of operation, if the WTRU determines that a timer value is smaller than a timer threshold. For example, the WTRU may determine that the timer value (e.g., RX_TIMER) is smaller than the configured timer threshold (e.g., RX_TIMER_MAX). Alternatively, the WTRU may select a second mode of operation, if the WTRU determines that the timer value is larger than the timer threshold. For example, the WTRU may determine that the timer value (e.g., RX_TIMER) is larger than the configured timer threshold (e.g., RX_TIMER_MAX). 34

[0162] The first and second modes of operation are described below.

[0163] Regarding monitoring and maintaining an Rx beam in the first mode of operation, a WTRU may receive and measure one or more first RS resources (e.g., SSB resources) from the first configured RS resource set. The WTRU may measure the first RS resources based on the configured TCI-states, where the WTRU may use the Rx beams that are associated with the configured TCI-states for receiving the corresponding first RS resources. The WTRU may measure one or more first parameters (e.g., first L1-RSRP) corresponding to the measured first RS resources.

[0164] The WTRU may report one or more of the first measured parameters (e.g., first L1-RSRP). The WTRU may send a request to the gNB requesting for and / or triggering the transmission of one or more second RS resources from the second RS resource set. The WTRU may report the RS index corresponding to the RS resource with one or more measured first parameters that is highest compared to the other RS resources. For example, the WTRU may report the index (e.g., SSB index, CRI, etc.) of the RS resource with highest measured first L1-RSRP.

[0165] The WTRU may receive one or more second RS resources, where the WTRU may measure one or more second parameters (e.g., second L1-RSRP). The WTRU may determine a second (e.g., new) (best) Rx beam based on the measured second parameters. The WTRU may determine one or more second measured parameters (e.g., second L1-RSRP) based on the determined second (best) Rx beam. In an example, the WTRU may determine the second (best) Rx beam based on the second measured parameter (e.g., second L1-RSRP), where the second measured parameter for the determined second (best) Rx beam has the highest value among other Rx beams.

[0166] A WTRU may determine the difference between a first measured parameter (e.g., first L1-RSRP) and a second measured parameter (e.g., second L1-RSRP). The WTRU may determine the mode of operation based on comparing the determined difference and a configured threshold for difference in measured parameters.

[0167] If the difference between the second measured L1-RSRP and the first measured L1-RSRP is larger than the corresponding threshold, the WTRU may reset the timer (e.g., RX_TIMER) and trigger and / or select a second mode of operation (e.g., reset stage) that may be based on Rx beam refinement and selection based on exhaustive search-based Rx beam determination. As such, the WTRU may report one or more second measured parameters (e.g., second L1-RSRP) and the timer reset event (e.g., RX_TIMER reset). The WTRU may transmit the report as part of a configured and / or scheduled CSI report.

[0168] If the difference between the second measured L1-RSRP and the first measured L1-RSRP is smaller than the corresponding threshold, the WTRU may reconfigure, update, and / or readjust the timer. That is, the WTRU may subtract a configured time offset value (e.g., T_MINUS) from the timer value (e.g., RX_TIMER). The WTRU may report one or more second measured parameters (e.g., second L1-RSRP) and the timer value (e.g., RX_TIMER). The WTRU may transmit the report as part of a configured and / or scheduled CSI report. 35

[0169] Regarding the second mode of operation, in which Rx beam refinement and selection may be based on exhaustive search-based Rx beam determination (e.g., reset stage), a WTRU may send a request (e.g., to a gNB) to receive the second RS resource set. In an example, the WTRU may perform Rx beam training based on the received second RS resource set. In another example, the WTRU may perform exhaustive search-based Rx beam determination based on the received second RS resource set.

[0170] The WTRU may send the request via explicit indication. For example, the WTRU may indicate the request via a flag indication. In an example, the WTRU may send the flag indication as part of the CSI report. Alternatively, the WTRU may send the request via implicit indication. In an example, the WTRU may indicate the request via sending timer reset event indication (e.g., RX_TIMER reset) as part of the reported CSI. In another example, the WTRU may indicate the request implicitly via reporting one or more measured second parameters as part of the reported CSI.

[0171] The WTRU may receive the second RS resource set and measure one or more third parameters based on the received second RS resource set. The WTRU may select and / or determine a third (best) Rx beam for at least one of the second RS resources. The WTRU may determine one or more third measured parameters (e.g., third L1- RSRP) based on the determined third (best) Rx beam. The WTRU may report (e.g., to a gNB) the third measured parameters (e.g., third) as part of CSI report.

[0172] Determining, monitoring, and maintaining auxiliary Rx beams based on positioning may be summarized as follows. A WTRU may receive a configuration of TCI-states, a first RS resource set where each RS is associated with a TCI state, a second RS resource set (e.g., aperiodic) (e.g., where all RS resources are configured with repetition), a threshold for position difference, a threshold for orientation difference, a threshold for L1-RSRP difference, the association between the first RS resources of the first RS resource set and the second RS resources of the second RS resource set, or any appropriate combination thereof.

[0173] The WTRU may measure RSs of the first RS resource set using the TCI-states (i.e., using a first set of Rx beams determined from the configured TCI-states) and determines its relative position (from gNB), orientation and a first set of L1-RSRP values. The WTRU may determine positioning / movement orientation information through other means e.g., through location services (LC).

[0174] The WTRU may maintain REF_POSITION and REF_ORIENTATION parameters. If REF_POSITION / ORIENTATION not set, the WTRU may set REF_POSITION / ORIENTATION = current position / orientation.

[0175] The WTRU may report a first set of L1-RSRP values and based on the WTRU’s relative position and orientation (e.g., If |WTRU position – REF_POSITION| > threshold OR |WTRU orientation – REF_ORIENTATION| > threshold), the WTRU may send an indication indicating |WTRU position / orientation – 36   REF_POSITION / ORIENTATION| > threshold. The WTRU may send a request to the gNB requesting at least one RSs of the second RS resource set (e.g., to determine at least one second best Rx beams) by indicating a beam index (CRI, SSB index) of a WTRU-determined beam from the first RS resource set (e.g., CRI of the RS with highest L1-RSRP) or a beam index of a beam from the second RS resource set configured to be associated with the WTRU- determined beam of the first RS resource set. The WTRU may receive a confirmation and indication of the RSs from second RS resource set to be transmitted (e.g., bit map). The WTRU may receive and may measure the at least one second RS resources and determines a second Rx beam (e.g., second best Rx beams) and a second L1-RSRP value based on the second best Rx beam for the WTRU-determined and indicated beam index. The WTRU may report the second L1-RSRP value to the gNB (e.g., as part of next CSI-Report). Based on the second L1-RSRP (e.g., if the difference between the second L1-RSRP value and the first L1-RSRP value for the WTRU-determined and indicated beam index is greater than threshold), the WTRU may trigger the reset stage. Based on the second L1- RSRP value (e.g., if the difference between the second L1-RSRP value and the first L1-RSRP value for the WTRU- determined and indicated beam index is less than or equal to the threshold), the WTRU updates REF_POSITION and REF_ORIENTATION parameters with its current position and orientation, respectively.

[0176] Regarding the reset stage, the WTRU may send a request to the gNB requesting the transmission of all RSs in the second RS resource set (e.g., for new round of Rx beam training). (e.g., implicit request via reporting some measurement or parameter through CSI-Report e.g., WTRU indicating position / orientation change). The WTRU may measure the transmitted resources of the second RS resource set and determines a second set of best Rx beams (e.g., one for each RS) and second set of L1-RSRP values of the RSs based on the second set of best Rx beams. The WTRU may determine its relative position, orientation and may update its REF_POSITION and REF_ORIENTATION parameters with its current position and orientation, respectively. The WTRU may report to gNB the measured second set of L1-RSRP values (e.g., via sending a request for a resource for CSI-Report).

[0177] For AIML beam inference, accurate beam quality measurements (e.g., RSRP, SINR) may be beneficial. To this end, measuring Tx beams (RS resources) using a suitable Rx beam (e.g., the best available Rx beam) may be warranted. However, as a WTRU changes its position / location (e.g., WTRU is in a vehicle and the vehicle is moving, the WTRU is held by a pedestrian user) and / or orientation (e.g., the WTRU changes its orientation due to moving from one ear to another by the user), Rx beams used for beam measurements also may need to be changed. To this end, a WTRU may determine the need for switching Rx beam based on the change of its position and / or orientation.

[0178] A WTRU may receive configuration information, where the configuration information may include one or more of the following (e.g., via RRC signaling, MAC-CE indication, DCI indication). The configuration information may include one or more TCI states. For example, the WTRU may be configured with a one or more TCI states via RRC signaling, MAC-CE indication or DCI indication. 37

[0179] The configuration information may include a first RS resource set. For example, the WTRU may be configured with a first RS resource set (configured and / or indicated via RS resource set ID and / or indices of RS resources) which includes one or more first RS resources. In an example, the first RS resource set may include SSB resources and / or CSI-RS resources. For example, the WTRU may be configured with SSB indices and / or CSI-RS resource indices corresponding to the SSBs and / or CSI-RSs included in the first RS resource set. Each of the one or more RS resources in the RS resource set may be associated with a TCI state. In an example, the association between RS resources in the RS resource set and the TCI states are configured / indicated via RRC signaling, and / or MAC-CE indication, and / or DCI indication. In another example, the WTRU may determine the association between the RS resources in the first RS resource set and a group of TCI states by a default configuration (e.g., 1 to 1 relationship where first TCI state is associated with the first RS resource, the second TCI sate is associated with the second TCI state and so forth).

[0180] The configuration information may include a second RS resource set. For example, the WTRU may be configured with a second RS resource set which includes one or more second RS resources. In an example, the second RS resource set may include one or more SSB resources and / or one or more CSI-RS resources. The second RS resource set may associate with one or more resource configurations. The configurations may include RS resource type (e.g., aperiodic), number of repetitions (e.g., more than 1), and so forth. The second RS resources may be transmitted (e.g., sweeping) from a transmitter (e.g., a gNB) through different spatial filters and / or in different directions within a configured time and frequency resources. In an example, the WTRU may use the second RS resources for Rx beam determination or refinement (e.g., based on an exhaustive Rx beam search).

[0181] The configuration information may include the association between the RS resources of the first RS resource set and the RS resources of the second RS resource set.

[0182] The configuration information may include a threshold for position difference. For example, a threshold for position difference to determine if the WTRU has changed its position compared to a refence position such that refining Rx beams / determining new Rx beams for a RS resource set (e.g., second RS resource set).

[0183] The configuration information may include a threshold for orientation difference. For example, a threshold for orientation difference to determine if the WTRU has changed its orientation compared to a refence orientation such that it requires to refine Rx beams / determine new Rx beams for a RS resource set (e.g., second RS resource set).

[0184] The configuration information a threshold for difference in beam quality measurement. For example, a threshold for RSRP difference, a threshold for SINR difference, and so forth.

[0185] The WTRU may maintain a reference position measurement / estimation (REF_POSITION) and / or a reference orientation measurement / estimation (REF_ORIENTATION) parameters. For example, if REF_POSITION 38   and / or REF_ORIENTATION not set, the WTRU may set REF_POSITION and / or REF_ORIENTATION based on its current position and orientation. In another example, if REF_POSITION and / or REF_ORIENTATION is not set, the WTRU may set REF_POSITION and / or REF_ORIENTATION based on its last position and orientation measurements / estimates. In another example, the WTRU may determine its positioning and / or orientation based on the information received from the gNB / network (e.g., location services (LC)). The WTRU may set the REF_POSITION and / or REF_ORIENTATION based on the gNB positioning and / or orientation information received from the gNB / the network.

[0186] The WTRU may compare its position and / or orientation with reference position and / or orientation to determine the need for new Rx beam selection. For example, the WTRU may compare its position and / or orientation with REF_POSITION and / or REF_ORIENTATION. To this end, the WTRU may determine its current positions and / or orientation based on its measurements or gNB / network configuration (e.g., LC). Then the WTRU may determine the need for new Rx beam selection by comparing the difference between its position (WTRU position) and the reference position (REF_POSITION) with the threshold for position difference and / or by comparing the difference between its orientation (WTRU orientation) and the refence orientation (REF_ORIENTATION) with the threshold for orientation difference. If the WTRU determines that its position compared to a refence position (|WTRU position – REF_POSITION|) > threshold for position difference or its orientation compared to reference orientation (|UE orientation – REF_ORIENTATION|) > threshold for orientation difference, the WTRU may decide that new Rx beam selection is needed. If the WTRU determines that |WTRU position – REF_POSITION| < threshold for position difference and |WTRU orientation – REF_ORIENTATION| < threshold for orientation difference, the WTRU may decide that new Rx beam selection is not needed.

[0187] Regarding Rx beam refining / selecting / reselecting, or maintaining based on position and / or orientation, the WTRU may receive and may measure RSs configured for measuring / estimating / determining position(location) and / or orientation and measure / estimate / determine its position and / or orientation. For example, the WTRU may use a first RS resource set with the associated TCI-states (i.e., using Rx beams corresponding to the TCI-states associated with each first RS) and determines its position or relative position (e.g., in reference to the position of the gNB), and orientation. The WTRU may also measure / estimate one or more beam quality measurements (e.g., L1-RSRP) associated with one or more first RS resources.

[0188] The WTRU may receive configuration / indication for receiving, measuring and / or reporting beam measurements (e.g., RSRP) associated with the first RS resource set. For example, the WTRU may receive from the gNB (e.g., via RRC signaling, MAC-CE indication or DCI indication) a request for reporting beam measurements associated with a beam report configuration (e.g., CSI report configuration). The WTRU may receive and measure / estimate one or more beam measurements (e.g., RSRP) of one or more first RS resources in the first RS resource set. The WTRU may receive the first RSs based on the associated TCI-states, where the WTRU may use 39   the Rx beams that are associated with the configured TCI-states for receiving the corresponding first RSs. The WTRU may report measured / estimated beam quality measurement to the gNB via configured UL resources (e.g., PUCCH, PUSCH) associate with the beam report configuration (e.g., CSI report configuration).

[0189] The WTRU that receives a request for configuration / indication for receiving, measuring and / or reporting beam measurements associate with one or more RS resources of the first RS resource set may determine its position and / or orientation. Based on the determined WTRUs position and / or orientation compared to the refence position and / or orientation, the WTRU may request / indicate the gNB for transmitting RS resources of the second RS resource set. Based on the beam quality measurement associate with one or more second RS resources and one or more beam quality measurement associates with the first RS resource set, the WTRU may determine the need for Rx beam reselection. For example, the WTRU which determines its position compared to a refence position (|WTRU position – REF_POSITION|) > threshold for position difference or its orientation compared to reference orientation (|WTRU orientation – REF_ORIENTATION|) > threshold for orientation difference, may perform one or more of the following steps to determine the need for Rx beam reselection and to reselect Rx beams.

[0190] The WTRU may indicate the gNB that its position compared to a refence position (|WTRU position – REF_POSITION|) > threshold for position difference and / or its orientation compared to reference orientation (|WTRU orientation – REF_ORIENTATION|) > threshold for orientation difference. For example, the WTRU may indicate that position difference or orientation difference exceeds respective thresholds by transmitting a 1-bit indication via a PUCCH, or MAC-CE or RRC signaling, or via transmitting a preconfigured PRACH resource. In another example, the WTRU may transmit two-bits, where the first and the second bit indicate the statues of position difference and orientation difference compared the respective thresholds (e.g., first bit value = 1 if the position difference > the threshold for position difference, first bit value = 0 if the position difference < the threshold for position difference. The second bit value = 1 if the orientation difference > the threshold for orientation difference. The second bit value = 0 if the orientation difference < the threshold for orientation difference).

[0191] The WTRU may transmit an indication to the gNB (e.g., via PUCCH indication, MAC-CE indication, or RRC signaling, or by transmitting a preconfigured PRACH resource) to transmit / trigger transmitting a first subset (e.g., one or more) of second RS resources from the second RS resource set. To this end, the WTRU may use one or more of the following solutions.

[0192] The WTRU may report beam indices (e.g., CRI, SSB index) and beam quality measurements (e.g., RSRP) associated with one or more of the RS resources belonging to the first RS resource set (e.g., via PUCCH indication, MAC-CE indication, RRC signaling). For example, the WTRU may determine the RS resource belongs to the first RS resource set with the highest beam quality measurement (e.g., RSRP) and reports its RS index (e.g., CRI, SSB index) and the beam quality measurement (e.g., RSRP) to the gNB. The gNB may determine the first subset of second RS resources (e.g., based on the association between the first RS resources and second RS resources). The 40   WTRU may receive configuration / indication from the gNB for the first subset of second RS resources (e.g., via PDCCH indication, MAC-CE indication, RRC signaling). For example, the WTRU may receive a bit map indicating transmitted one or more second RS resources out of all the second RS resources in the second RS resource set. In another example, the WTRU may receive the RS indices (e.g., CRI, SSB index, CSI-RS resource index) of one or more second RS resources.

[0193] The WTRU may determine a second subset of second RS resources it is expected to receive from the gNB for Rx beam determination based on the association between the first RS resources and second RS resources, and beam quality measurements associated with the first RS resource set. For example, the WTRU may select one or more second RS resources associated with the first RS resource with the best beam quality measurement as the second subset of second RS resources. The WTRU may indicate the selected second subset of second RS resources to the gNB (e.g., via PUCCH, MAC-CE, RRC signaling, by transmitting one or more PRACH resources associates with (e.g., each) second RS resources of the second subset). The WTRU may monitor for a confirmation indication from the gNB (e.g., via PDCCH indication, MAC-CE indication, RRC signaling) for the indicated second subset set of second RS resource request. The WTRU may receive a confirmation indication from the gNB or alternatively receive a configuration / indication from the gNB to receive one or more third subset of second RS resources (e.g., second RSs resources different from the selected and indicated second subset of second RSs).

[0194] The WTRU may receive one or more second RSs of the first subset of second RSs or third subset of second RSs with a configured number of repetitions (e.g., the number of repetitions configured as a part of second RS resource set configuration, an indicated number of repetitions by the WTRU via PUCCH indication and / or MAC- CE indication and / or RRC signaling). The WTRU may use the one or more second RS resource (belongs to first subset or third subset of second RS resources) along with the repetitions (e.g., each repetition of a second RS resource is received and measured by a different Rx beam by the WTRU) to measure beam quality measurements and determine a suitable Rx beam (e.g., the best Rx beam; Rx beam corresponds to the highest beam quality measurement) for each of the second RS resources received. For example, the WTRU may receive a second beam configured / indicated via first subset of second RS resources or the third subset of second RS resources and associated repetitions. The WTRU may receive and measure RSRP of each repetition of the second RS resource with a different Rx beam to determine the Rx beam that provides the highest RSRP. The WTRU may report beam quality measurements of one or more second beams (e.g., corresponding to the best Rx beam) to the gNB (e.g., as part of subsequent CSI-Report).

[0195] The WTRU may compare the beam quality measurements of one or more second RS resources (second RSs of the first subset of second RSs or third subset of second RSs) measured with determined Rx beams with the highest beam quality measurement of the first RS resource to determine the need for updating Rx beams (e.g., for future beam quality measurements for beam inference and / or model training). For example, the WTRU may compare 41   the difference between RSRP of a second RS resource measured with the determined Rx beam (e.g., RS and Rx beam corresponds to the highest RSRP) and the highest beam quality measurement out of the first RS resource set against the threshold for difference in beam quality measurement.

[0196] If the WTRU determines that difference in measured beam quality (difference between RSRP of a second RS resource measured with the determined Rx beam and the highest beam quality measurement out of the first RS resource set) > the threshold for difference in beam quality measurement, the WTRU may trigger a reset stage. In the reset stage, Rx beams are reselected for one or more (e.g., each) second RS resource in the second RS resource set.

[0197] For example, if |RSRP of the second RS with the highest RSRP – the highest RSRP of the first RS resource set| < threshold for RSRP difference, the WTRU may trigger the reset stage.

[0198] If the WTRU determines that difference in measured beam quality < the threshold for difference in beam quality measurement, the WTRU may the WTRU updates REF_POSITION and REF_ORIENTATION parameters with its current position and orientation, respectively.

[0199] Regarding Rx beam determination in the reset stage, a WTRU that was triggered to reset stage for Rx beam selection / reselection may follow one or more of the following procedures. The WTRU may send a request to the gNB requesting the second RS resource set (e.g., for a new round of Rx beam training). For example, the WTRU may send an implicit request via reporting one or more configured measurement or parameter through a CSI-Report (e.g., WTRU indicating position / orientation change). In another example, the WTRU may transmit one bit indication.

[0200] The WTRU may receive and measure beam quality measurements (e.g., RSRP) of one or more second RS resources (e.g., each second RS resource) using different (more than one) Rx beams (e.g., using a different Rx beam for each repetition of a second RS resource). Using the measurements, the WTRU may determine a Rx beam (e.g., the Rx beam providing the highest RSRP) for one or more second RS resource (e.g., each second RS resource) and the corresponding beam quality measurements of one or more second RS resources (e.g., RSRP measurement of each second RS resource with the determined best Rx beam).

[0201] The WTRU may request and receive UL resources (e.g., PUCCH resources, or PUSCH resources) for reporting the measured beam quality measurements of second RS resources (e.g., the beam quality measurement with the determined best Rx beams). Using the received UL resources, the WTRU may report the beam quality measurements of one or more RS resources belongs to the second RS resource set measured with the determined Rx beam (e.g., the Rx beams providing the highest RSRP).

[0202] The WTRU may determine its position (e.g., relative position compared to the gNB), orientation and updates its REF_POSITION and REF_ORIENTATION parameters with its current position and orientation, 42   respectively. The WTRU may report to the gNB its REF_POSITION and REF_ORIENTATION parameters (e.g., via PUCCH, PUSCH, RRC signaling). 43

Claims

CLAIMS What is claimed is:

1. A wireless transmit / receive unit (WTRU) comprising: a transceiver; and a processor configured to: measure a plurality of channel state information (CSI) reference signals (RSs) of a first CSI-RS resource set using a first receive (Rx) beam to determine a first set of layer-1 (L1) reference signal received power (RSRP) values for each CSI-RS resource of the first CSI-RS resource set; determine a L1-RSRP difference of a first CSI-RS resource of the first CSI-RS resource set based on the L1-RSRP values of the CSI-RS set; based on the determined L1-RSRP difference being greater than a first threshold: send, via the transceiver, a CSI-RS resource indicator (CRI) comprising an indication of the CSI-RS resource of the first CSI-RS resource set having an L1-RSRP value resulting in the L1-RSRP difference being greater than the first threshold; and send a request, via the transceiver, for at least one CSI-RS resource of a second CSI-RS resource set; measure a CSI-RS of the at least one CSI-RS resource of the second CSI-RS resource set to determine a second Rx beam and a second L1-RSRP value associated with the first CSI-RS resource of the first CSI-RS resource set; and based on the first L1-RSRP value and the second L1-RSRP value, determine the second Rx beam.

2. The WTRU of claim 1, the processor further configured to: receive, via the transceiver, one or more synchronization signal / physical broadcast channel blocks (SSBs) of an SSB resource set; and determine the first Rx beam based on a search of each SSB of the SSB resource set.

3. The WTRU of claim 2, wherein the second Rx beam is determined based on CSI-RSs associated with the SSB resource set. 44   4. The WTRU of claim 2, wherein the L1-RSRP difference of the first CSI-RS resource is between an L1-RSRP of an SSB of the SSB resource set and a respective measured L1-RSRP value.

5. The WTRU of claim 1, wherein the processor is configured to: send a request, via the transceiver, for all CSI-RSs of the second CSI-RS resource set, use a plurality of Rx beams to measure CSI-RSs of the second CSI-RS resource set; and determine the second Rx beam based on measuring the CSI-RSs of the second CSI-RS resource set, wherein the second Rx beam is associated with an Rx beam of the plurality of Rx beams having a highest RSRP value.

6. The WTRU of claim 1, wherein the processor is configured to send a request, via the transceiver, for all CSI-RSs of the second CSI-RS resource set based on an average difference of the second L1-RSRP value and L1-RSRP values of the first set of L1-RSRP values being greater than a second threshold.

7. The WTRU of claim 1, wherein the processor is configured to, based on a difference between the first L1-RSRP value and the second L1-RSRP value being greater than a second threshold, send a request, via the transceiver, for a CSI report.

8. The WTRU of claim 1, wherein the processor is configured to, based on a difference between the first L1-RSRP value and the second L1-RSRP value being greater than a second threshold, send, via the transceiver, an indication of the difference between the first L1-RSRP value and the second L1-RSRP value.

9. The WTRU of claim 1, wherein the WTRU is configured to receive, via the transceiver, configuration information comprising at least one of a synchronization signal / physical broadcast channel block (SSB) resource set, a transmission configuration indicator (TCI) state, a first CSI-RS resource set wherein each CSI-RS is associated with a TCI state, a reference RS, a second CSI-RS resource set, the first threshold, or a second threshold. 45   10. The WTRU of claim 1, wherein to determine the first set of L1-RSRP values comprises to determine a difference between a highest L1-RSRP value of a CSI-RS resource of the CSI-RS resource set configured as a quasi co- location (QCL) type reference signal RS and a lowest L1-RSRP value of a CSI-RS resource of the CSI-RS resource set configured as a QCL type RS.

11. The WTRU of claim 1, wherein to determine the first set of L1-RSRP values comprises to determine a difference between a highest L1-RSRP value of a CSI-RS of the CSI-RS resource set configured as a quasi co-location (QCL) type RS and at least one other L1-RSRP value of a CSI-RS of the CSI-RS resource set configured as a QCL type RS.

12. A method performed by a wireless transmit / receive unit (WTRU), the method comprising: measuring a plurality of channel state information (CSI) reference signals (RSs) of a first CSI-RS resource set using a first receive (Rx) beam to determine a first set of layer-1 (L1) reference signal received power (RSRP) values for each CSI-RS resource of the first CSI-RS resource set; determining a L1-RSRP difference of a first CSI-RS resource of the first CSI-RS resource set based on the L1-RSRP values of the CSI-RS set; based on the determined L1-RSRP difference being greater than a first threshold: sending a CSI-RS resource indicator (CRI) comprising an indication of the CSI-RS resource of the first CSI-RS resource set having an L1-RSRP value resulting in the L1-RSRP difference being greater than the first threshold; and sending a request for at least one CSI-RS resource of a second CSI-RS resource set; measuring a CSI-RS of the at least one CSI-RS resource of the second CSI-RS resource set to determine a second Rx beam and a second L1-RSRP value associated with the first CSI-RS resource of the first CSI-RS resource set; and based on the first L1-RSRP value and the second L1-RSRP value, determining the second Rx beam.

13. The method of claim 12, further comprising: receiving one or more synchronization signal / physical broadcast channel blocks (SSBs) of an SSB resource set; and 46   determining the first Rx beam based on a search of each SSB of the SSB resource set.

14. The method of claim 13, wherein the second Rx beam is determined based on CSI-RSs associated with the SSB resource set.

15. The method of claim 13, wherein the L1-RSRP difference of the first CSI-RS resource is between an L1-RSRP of an SSB of the SSB resource set and a respective measured L1-RSRP value.

16. The method of claim 12, further comprising: sending a request for all CSI-RSs of the second CSI-RS resource set, using a plurality of Rx beams to measure CSI-RSs of the second CSI-RS resource set; and determining the second Rx beam based on measuring the CSI-RSs of the second CSI-RS resource set, wherein the second Rx beam is associated with an Rx beam of the plurality of Rx beams having a highest RSRP value.

17. The method of claim 12, further comprising sending a request for all CSI-RSs of the second CSI-RS resource set based on an average difference of the second L1-RSRP value and L1-RSRP values of the first set of L1-RSRP values being greater than a second threshold.

18. The method of claim 12, wherein, based on a difference between the first L1-RSRP value and the second L1- RSRP value being greater than a second threshold, the method further comprising sending at least one of a request for a CSI report or an indication of the difference between the first L1-RSRP value and the second L1-RSRP value.

19. The method of claim 12, wherein determining the first set of L1-RSRP values comprises to determine a difference between a highest L1-RSRP value of a CSI-RS resource of the CSI-RS resource set configured as a quasi co-location (QCL) type reference signal RS and a lowest L1-RSRP value of a CSI-RS resource of the CSI-RS resource set configured as a QCL type RS. 47   20. The method of claim 12, wherein determining the first set of L1-RSRP values comprises to determine a difference between a highest L1-RSRP value of a CSI-RS of the CSI-RS resource set configured as a quasi co- location (QCL) type RS and at least one other L1-RSRP value of a CSI-RS of the CSI-RS resource set configured as a QCL type RS. 48

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