EP4662797A1

EP4662797A1 - Reducing the overhead of beam reporting by exploiting the correlation between beams

Info

Publication number: EP4662797A1
Application number: EP24713056.0A
Authority: EP
Inventors: Prasanna Herath; Young Woo KWAK; Patrick J. Tooher; Moon-Il Lee; Yugeswar Deenoo NARAYANAN THANGARAJ; Ahmed Mostafa; Nazli KHAN BEIGI; Tejaswinee LUTCHOOMUN; Haseeb UR REHMAN
Original assignee: InterDigital Patent Holdings Inc
Current assignee: InterDigital Patent Holdings Inc
Priority date: 2023-02-07
Filing date: 2024-02-07
Publication date: 2025-12-17
Also published as: WO2024168059A9; WO2024168059A1; CN120937262A; KR20250143322A

Abstract

Systems, methods, devices, and instrumentalities are described herein related to spatial and temporal domain compression associated with reducing beam reporting overhead. A wireless transmit/receive unit (WTRU) may determine assistance information and report the assistance information to a network node. Based on reporting (e.g., after reporting) the assistance information to the network node, configuration information may be received. The configuration information may indicate a set of reference signal (RS) resources. Measurements of the set of RS resources may be performed. The WTRU may determine that sparse reporting is activated based on the measurements of the set of the RS resources. Based on the sparse reporting being activated, a subset of RS resources may be selected for measurement reporting from the set of RS resources. The selected subset of RS resources and measurements associated with the subset of RS resources may be reported.

Description

REDUCING THE OVERHEAD OF BEAM REPORTING BY EXPLOITING THE CORRELATION BETWEEN BEAMS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Provisional U.S. Patent Application No. 63/443,902, filed February 7, 2023, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] Mobile communications using wireless communication continue to evolve. A fifth generation of mobile communication radio access technology (RAT) may be referred to as 5G new radio (NR). A previous (legacy) generation of mobile communication RAT may be, for example, fourth generation (4G) long term evolution (LTE).

SUMMARY

[0003] Systems, methods, devices, and instrumentalities are described herein related to reducing the overhead of beam reporting by exploiting the correlation between beams.

[0004] A wireless transmit/receive unit (WTRU) may determine assistance information and report the assistance information to a network node. Based on reporting (e.g., after reporting) the assistance information to the network node, configuration information may be received. The configuration information may indicate a set of reference signal (RS) resources. Measurements of the set of RS resources may be performed. In examples, the measurements of the set of RS resources may be reported at a number of reporting instances (e.g., an initial number of reporting instances). The WTRU may determine that sparse reporting is activated. In examples, the WTRU may determine that sparse reporting is activated based on the measurements of the set of the RS resources. In examples, the WTRU may determine that the sparse reporting is activated is based on time-domain differential measurements of a number of beams in the set of RS resources being less than a sparse reporting activation threshold. [0005] Based on the sparse reporting being activated, a subset of RS resources may be selected for measurement reporting from the set of RS resources. In examples, the subset of RS resources may be selected from a set of subsets of RS resources. In examples, the selection of the subset of RS resources may be based on a magnitude of time-domain differential measurements exceeding a sparse reporting beam selection threshold. In examples, the selection of the subset of RS resources may be based on a magnitude of RS resource differential measurements exceeding a sparse reporting beam selection threshold. In examples, the selection of the subset of RS resources may be based on a preconfigured pattern.

[0006] The selected subset of RS resources and measurements associated with the subset of RS resources may be reported. In examples, the measurements of the subset of RS resources may be reported at a sparse reporting instance based on the sparse reporting being activated. In examples, the reporting of the subset of RS resources at the sparse reporting instance may occur after the measurements of the set of RS resources that are reported at the number of reporting instances (e.g., the initial number of reporting instances). In examples, the subset of RS resources may be reported within a bitmap (e.g., if the selection of the subset of RS resources is based on a magnitude of time-domain differential measurements or a magnitude of RS resource differential measurements exceeding the sparse reporting beam selection threshold). In examples, the subset of RS resources may be reporting via a pattern ID (e.g., if the selection of the subset of RS resources is based on a preconfigured pattern).

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0008] FIG. 1 B is a system diagram illustrating an example wireless transmit/receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment.

[0009] FIG. 1 C is a 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. 1 A according to an embodiment.

[0010] FIG. 1 D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A according to an embodiment.

[0011] FIG. 2 illustrates an example variation of an L1 -RSRP with elevation and azimuth angles.

[0012] FIG. 3 illustrates an example variation of L1-RSRP of beams with time. [0013] FIG. 4 illustrates an example variation of L1 -RSRP across different sectors/panels.

[0014] FIG. 5 illustrates an example of differential L1 -RSRP using a maximum L1-RSRP beam as the reference beam.

[0015] FIG. 6 illustrates an example of differential L1 -RSRP using the adjacent beam as the reference beam.

[0016] FIG. 7 illustrates an example of differential L1 -RSRP with two reference beams

[0017] FIG. 8 illustrates an example of beam reporting over consecutive measurement instances with sparse reporting.

[0018] FIG. 9 illustrates an example of beam measurement reporting with sparse reporting.

DETAILED DESCRIPTION

[0019] 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.

[0020] 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 ON 106/115, a public switched telephone network (PSTN) 108, the I nternet 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, 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 “ST A”, 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 (loT) 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.

[0021] 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 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.

[0022] 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 overtime. 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.

[0023] 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). [0024] 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).

[0025] 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).

[0026] 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).

[0027] 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).

[0028] 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, CDMA2000 1X, 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.

[0029] The base station 114b in FIG. 1 A 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 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. 1 A, 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.

[0030] 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.

[0031 ] 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.

[0032] 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.

[0033] FIG. 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, 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 WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0034] 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. 1 B 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.

[0035] 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.

[0036] Although the transmit/receive element 122 is depicted in FIG. 1 B 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.

[0037] 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 I EEE 802.11 , for example.

[0038] 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 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).

[0039] 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.

[0040] 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 locationdetermination method while remaining consistent with an embodiment. [0041] 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.

[0042] 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 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 WRTU 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 uplink (UL) (e.g., for transmission) or the downlink (e.g., for reception)).

[0043] FIG. 1 C 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.

[0044] 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.

[0045] 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. 1 C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0046] The CN 106 shown in FIG. 1 C 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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. [0051] Although the WTRU is described in FIGS. 1A-1 D 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.

[0052] In representative embodiments, the other network 112 may be a WLAN.

[0053] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (ST As) 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 802.11 z 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.

[0054] 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 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.

[0055] 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. [0056] Very High Throughput (VHT) ST As 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 ST A, 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).

[0057] Sub 1 GHz modes of operation are supported by 802.11 af and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.11 af and 802.11 ah relative to those used in 802.11 n, and 802.11ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11 ah 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).

[0058] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11n, 802.11 ac, 802.11af, and 802.11 ah, 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 802.11 ah, 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), 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. [0059] In the United States, the available frequency bands, which may be used by 802.11 ah, 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 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0060] FIG. 1 D 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.

[0061] 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, 108b 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).

[0062] 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).

[0063] 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 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.

[0064] 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. 1 D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0065] The CN 115 shown in FIG. 1 D 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.

[0066] 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 access technologies such as WiFi.

[0067] 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 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.

[0068] 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.

[0069] 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.

[0070] In view of Figures 1A-1 D, and the corresponding description of Figures 1A-1 D, 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. [0071] 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 performing testing using over-the-air wireless communications.

[0072] 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 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.

[0073] Reference to a timer herein may refer to determination of a time or determination of a period of time. Reference to a timer expiration herein may refer to determining that the time has occurred or that the period of time has expired. Reference to a timer herein may refer to a time, a time period, tracking the time, tracking the period of time, etc.

[0074] Systems, methods, devices, and instrumentalities are described herein related to reducing the overhead of beam reporting by exploiting the correlation between beams.

[0075] A wireless transmit/receive unit (WTRU) may determine assistance information and report the assistance information to a network node. Based on reporting (e.g., after reporting) the assistance information to the network node, configuration information may be received. The configuration information may indicate a set of reference signal (RS) resources. Measurements of the set of RS resources may be performed. In examples, the measurements of the set of RS resources may be reported at a number of reporting instances (e.g., an initial number of reporting instances). The WTRU may determine that sparse reporting is activated. In examples, the WTRU may determine that sparse reporting is activated based on the measurements of the set of the RS resources. In examples, the WTRU may determine that the sparse reporting is activated is based on time-domain differential measurements of a number of beams in the set of RS resources being less than a sparse reporting activation threshold. [0076] Based on the sparse reporting being activated, a subset of RS resources may be selected for measurement reporting from the set of RS resources. In examples, the subset of RS resources may be selected from a set of subsets of RS resources. In examples, the selection of the subset of RS resources may be based on a magnitude of time-domain differential measurements exceeding a sparse reporting beam selection threshold. In examples, the selection of the subset of RS resources may be based on a magnitude of RS resource differential measurements exceeding a sparse reporting beam selection threshold. In examples, the selection of the subset of RS resources may be based on a preconfigured pattern.

[0077] The selected subset of RS resources and measurements associated with the subset of RS resources may be reported. In examples, the measurements of the subset of RS resources may be reported at a sparse reporting instance based on the sparse reporting being activated. In examples, the reporting of the subset of RS resources at the sparse reporting instance may occur after the measurements of the set of RS resources that are reported at the number of reporting instances (e.g., the initial number of reporting instances). In examples, the subset of RS resources may be reported within a bitmap (e.g., if the selection of the subset of RS resources is based on a magnitude of time-domain differential measurements or a magnitude of RS resource differential measurements exceeding the sparse reporting beam selection threshold). In examples, the subset of RS resources may be reporting via a pattern ID (e.g., if the selection of the subset of RS resources is based on a preconfigured pattern).

[0078] A WTRU may determine a number of reference beams based on beam measurements and/or a network (e.g., network node or gNB) configuration (e.g., configuration information). The WTRU may select reference beams based on a gNB configuration and/or beam measurements. The WTRU may group beams into subsets. The subsets may associate groups to reference beams (e.g., each group to a reference beam). The WTRU may report beam measurements of reference beams and beam IDs. For groups of beams (e.g., for each group of beams), the WTRU may compute and report differential beam measurements based on associated reference beams.

[0079] The WTRU may report assistant information for the network node (e.g., gNB) to determine the need for beam measurements (e.g., updated beam measurements) for beam inference or model training.

[0080] In examples, for a configured beam resource set, the WTRU may report beam measurements corresponding to multiple time instances by measuring and reporting beam measurements of beams (e.g., all beams) in the resource set that may correspond to a number of k measurement instances (e.g., an initial number of k measurement instances). In examples, for a configured beam resource set, the WTRU may report beam measurements corresponding to multiple time instances by measuring and reporting beam measurements of a subset of selected beams in the resource set (e.g., sparse reporting) for the measurement instances after the kth instance. The WTRU may report beams selected at measurement instances (e.g., each measurement instance) to the gNB.

[0081] The WTRU may report beam measurements of a selected measurement instance (e.g., a representative measurement instance) out of configured number of measurement instances (e.g., L measurement instances). The WTRU may report (e.g., additional) measurement and/or computed parameters based on measurements to the gNB (e.g., a maximum measurement of a beam in L measurement instances and the corresponding time instance).

[0082] The WTRU may measure beams corresponding to a number of resource sets (e.g, M > 1). The WTRU may determine the selected and non-selected beam resource sets for measurement reporting based on a criteria (e.g, criteria X) configured by the gNB. The WTRU may report beam measurements determined by a configured reporting quantity assignment procedure (e.g, procedure Y) for selected and non-selected resource sets (e.g, based on criteria X). In examples, for a selected resource set (e.g, based on criteria X), a WTRU may report measurement(s) (e.g, L1-RSRP) of (e.g, all) the beams based on configured reporting quantity assignment procedure Y. For a non-selected resource set (e.g, based on criteria X), a WTRU may report an average beam measurement (e.g, an average L1 -RSRP over all the beams in the resource set) based on configured reporting quantity assignment procedure Y.

[0083] The WTRU may select reporting parameters (e.g, a maximum and minimum value of beam measurements, quantization step size, etc.) based on a configuration (e.g, configuration information) or beam measurements. The WTRU may determine and switch value reporting parameters based on a trigger condition and/or a stop condition for accurate reporting. The WTRU may determine a set (e.g, an updated set) of reporting parameters based on a configured fallback procedure (e.g, reduce step-size by one step etc.). The WTRU may determine values of reporting parameters based on required accuracy and/or beam measurements.

[0084] Beam measurements and reporting may be essential (e.g, for the proper operation of wireless communications in higher frequencies (e.g, FR2-1 , FR2-2)). An NR beam measurement and reporting mechanism may be a high-power consuming and delay causing operation. These mechanisms may (e.g, may further) require high signaling overhead (e.g, for transmitting reference signals and reporting beam measurements). Improvements for beam measurement and reporting may be highly beneficial for wireless systems operating in higher frequencies. AI/ML based examples for improving beam management are provided herein.

[0085] An AI/ML model implementation may locate the AI/ML capabilities at a network (e.g., network node or gNB) side. With this setup (e.g., for the model inference and model training), beam measurements may be performed by WTRUs and reported to the gNB side. This process may involve measuring, reporting beams (e.g., many beams which may be more than the number of beams required to be measured), and/or reporting beams at a time according to beam management examples. AI/ML based beam predictions may reduce the overall demand for beam measurements and reporting for at least the following reasons: if beam measurements for the model inference are provided to a trained AI/ML model, the model may predict beam measurements for a long duration of time before requiring new beam measurements; if an AI/ML model is trained, the trained model may be used to predict beams for many WTRUs including WTRUs that have not provided beam measurements for model training; and some of the beam measurements required for model training may not be time critical (e.g., these beam measurements may be reported if the NR air interface is underused or via other means (e.g., beam reports are sent via WLAN)).

[0086] During the model inference stage, beam selection with AI/ML models may be based on predictions. This may be faster compared to the existing NR beam selection process that depends on beam measurements reported by the WTRU.

[0087] If not properly designed, the need for measuring and reporting large number of beams for beam inference and model training may significantly undermine the advantages of using AI/ML models for beam management. This is particularly crucial if the AI/ML model is located at the gNB side in which the WTRU- gNB air interface may have to be used for beam reporting.

[0088] A WTRU may report a CSI-RS resource indicator (CRI) and L1 -RSRP of a beam with the highest L1-RSRP of a beam resource set (e.g., in the NR beam reporting framework). The WTRU may report (e.g., additionally report) L1-RSRP measurements of maximum up to three (e.g., additional) beams (as differential L1 -RSRPs) and their CRIs. In examples, reporting measurements of a few beams (e.g., L1 - RSRP of four beams) may be insufficient for providing beam measurements for model inference and model training if the AI/ML model is located at a network node (e.g., gNB). The number of beams and type of beam measurements to be reported (e.g., in the current CSI framework) may not be dynamically determined based on beam measurements experienced by the WTRU. The type of measurements associated with beams or beam resource sets to be reported may not (e.g., may also not) be dynamically determined based on beam measurements experienced by the WTRU. Supporting such dynamic behaviors may reduce the signaling overhead associated with beam reporting while the AI/ML model receives sufficient beam measurements for model inference and training.

[0089] Examples herein may allow a WTRU to report beam measurements of many beams potentially over several time instances with limited signaling overhead. Examples herein may allow beam reporting to be performed with limited signaling overhead while reducing quantization errors in the reported beam measurements. Examples herein may allow a WTRU to dynamically determine beams or beam resource sets for which beam measurements are to be reported. Examples herein allow a WTRU to determine measurement type (e.g., L1 -RSRP of each beam, average L1 -RSRP of all the beams) associated with a beam resource set or beams to be reported.

[0090] 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.

[0091] The WTRU may transmit a physical channel or signal using the same spatial domain filter as the spatial domain filter used for receiving an RS (e.g., such as CSI-RS) or a synchronization signal (SS) block. The WTRU transmission may be referred to as a “target”. The received RS or SS block may be referred to as a “reference” or a “source”. The WTRU may (e.g., in such cases) transmit the target physical channel or signal according to a spatial relation with a reference to such an RS or an SS block.

[0092] The 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 a “target” and a “reference” (or “source”), respectively. The WTRU may be said (e.g., in such cases) to transmit the first (e.g., target) physical channel or signal according to a spatial relation with a reference to the second (e.g., reference) physical channel or signal.

[0093] A spatial relation may be implicit, configured by RRC, or signaled by an MAC CE or a DCI. In examples, a WTRU may implicitly transmit a PUSCH and a DM-RS of a PUSCH according to the same spatial domain filter as an SRS indicated by an SRI indicated in a DCI or configured by an RRC. In examples, a spatial relation may be configured by an RRC for an SRS resource indicator (SRI) or signaled by an MAC CE for a PUCCH. Such spatial relation may (e.g., may also) be referred to as a “beam indication”.

[0094] The WTRU may receive a first (e.g., target) downlink channel or signal according to the same spatial domain filter or spatial reception parameter as a second (e.g., reference) downlink channel or signal. In examples, an association may exist between a physical channel such as a PDCCH or a PDSCH and its respective DM-RS. In examples, an association may exist if the WTRU is configured with a quasicolocation (QCL) assumption type D between corresponding antenna ports (e.g. , at least if the first and second signals are reference signals). Such association(s) may be configured as a transmission configuration indictor (TCI) state. A WTRU may be indicated as an association between a CSI-RS or SS block and a DM-RS by an index to a set of TCI states configured by an RRC and/or signaled by an MAC CE. Such an indication may (e.g., may also) be referred to as a “beam indication”.

[0095] Examples of beam measurement, beam quality measurement, and/or beam quality are provided herein. Beam measurement, beam quality measurement, and/or beam quality may refer to one or more of the following parameters measured, estimated, and/or derived based on measurements performed for a beam or set of beams: a reference signal received power (RSRP); a reference signal received quality (RSRQ); a received signal strength indicator (RSSI), a signal-to-interference-plus-noise ratio (SI NR); a channel quality indicator (CQI); a rank indicator (Rl); a layer indicator (LI); a precoding matrix indicator (PMI); a CRI; an angle of arrival (AoA); an angle of departure (AoD); a doppler spread; a doppler shift; an average doppler; a delay spread; an average delay; or a channel occupancy.

[0096] Differential beam measurement or spatial-domain differential beam measurement of two beams may be the difference between the two beam measurements. In examples, spatial-domain differential L1 - RSRP of two beams may be the difference between L1-RSRPs of the two beams.

[0097] Time-domain differential beam measurement of a beam may be the difference between beam measurements of the same beam at two time instances. In examples, the time-domain differential L1 - RSRP of a beam may be the difference between L1-RSRPs of the beam at two time instances.

[0098] FIG. 2 illustrates an example variation of an L1-RSRP with elevation and azimuth angles. Simulated L1-RSRPs results of different downlink beams (corresponding to different azimuth and elevation angles) experienced by a typical WTRU are shown in FIG. 2. The relationship between the beam indices and azimuth angles are given in Table 1 below. Table 1 : Relationship between beam indices and azimuth and elevation angles

[0099] Two beam measurements (e.g. , L1-RSRP) of beams with similar azimuth and elevation angles originated from the same panel or sector antennas may be correlated.

[0100] FIG. 3 illustrates an example variation of L-RSRP of beams with time. The variation of L1 -RSRPs of different downlink beams (corresponding to different azimuth and elevation angles) with time is shown in FIG. 3. The relationship between the beam indices and azimuth angles are given above in Table 1 .

[0101] Beam measurements (e.g., L1-RSRP) of a beam at two adjacent time instances may be correlated.

[0102] FIG. 4 illustrates an example variation of L1 -RSRP across different sectors/panels. Three possible scenarios the WTRUs served by a gNB with three antenna panels (or sectors) may experience are shown in FIG. 4. These include a WTRU that receives better quality beams (e.g., beams corresponding to higher L1 -RSRP) from, one out of three panels at the gNB, two out of three panels at the gNB, and all three panels at the gNB. The relationship between the beam indices and azimuth angles are given in Table 1. The same WTRU may (e.g., may also) experience all three scenarios at different times.

[0103] The number of antenna panels (or sectors) at the gNB that provide better beams (e.g., beams with higher L1-RSRP) may change from one WTRU to another. The number of antenna panels (or sectors) at the gNB that provide better beams (e.g., beams with higher L1-RSRP) for a WTRU may dynamically be changed.

[0104] Examples of configurations for reporting beam measurements are provided herein. A WTRU may receive one or more configurations and/or indications. The WTRU may determine to measure and report one or more beam resources. A beam resource may include one or more of: a TCI state, an SSB, a CSI- RS, a PT-RS, or a TRS for downlink. The beam resource may include one or more of: an SRS resource, or TCI state for uplink.

[0105] In examples, the WTRU may receive a SS/PBCH block (SSB). The SSB may include a PSS, SSS, and a PBCH. The WTRU may monitor, receive, or attempt to decode an SSB during initial access, initial synchronization, RLM, cell search, cell switching, etc.

[0106] In examples, the WTRU may measure and report the CSI. The CSI may include or be configured with one or more of following: a CSI report configuration; a CSI-RS resource set, or NZP CSI-RS resources. The CSI report configuration may include one or more of the following: a CSI report quantity, (e.g., L1-RSRP, SNR, CQI, Rl, PMI, CRI, LI, etc.); 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.) or a CSI report frequency. The CSI-RS resource set may include one or more of the following CSI resource settings: an NZP-CSI-RS resource for channel measurement; an NZP-CSI-RS resource for interference measurement; or a CSI-IM resource for interference measurement. The NZP CSI-RS resources may include one or more of the following: an NZP CSI-RS resource ID; a periodicity and offset; QCL info and TCI-state; or resource mapping (e.g., number of ports, density, CDM type, etc.).

[0107] In examples, a 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 examples, CSI report quantity may be one or more of the L1-RSRP, CQI, Rl, PMI, CRI, LI, or SINR.

[0108] The CSI report configuration may be associated with one or more CSI resource settings (e.g., CSI-ResourceConfig) for channel or interference measurement. A resource setting may include a list of CSI resource sets. The list of CSI resource sets may include references to one or more CSI-RS resource sets or SSB sets.

[0109] Examples of using the correlation between beams to reduce reporting overhead are provided herein. A WTRU may receive configuration information (e.g., from a network node or gNB) of the number of reference beams (e.g., CSI-RS resources) to be considered given the size of CSI-RS resource set (e.g., number of CSI-RS resources) and the beam measurements (e.g., measured L1 -RSRP values). The configuration information may include default settings for the beam reporting process (e.g., L1-RSRP reporting process), such as a default number of reference beams and/or enabling flag for beam measurement reporting. If reporting beam measurements (e.g., L1 -RSRP value), beam resources in a resource set may be ordered such that adjacent beams are correlated and/or have similar beam measurements (e.g., similar L1-RSRP values).

[0110] Examples of determining a number of reference beams for beam reporting are provided herein. The WTRU may determine or select the number of reference beams (e.g., beam reference signal including SS/PBCH blocks and CSI-RS resources) for which the WTRU may (e.g., may need to) report beam measurements (e.g., L1 -RSRP values) to the gNB. The aforementioned selection may be decided via one or more of the following examples.

[0111] The WTRU may consider a fixed number of reference beams (e.g., reference CSI-RS resources, a subset of CSI-RS resources) according to the size of the CSI-RS resource set. For example, the WTRU may consider reporting a single L1 -RSRP value for a single reference beam (CSI-RS resource) for every X CSI-RS resources. If the CSI-RS resource set includes NX CSI-RS resources, the WTRU may select (N or floor(N) or ceil(N) or round(N)) reference beams (reference CSI-RS resources). Such static configuration may be indicated by the gNB to the WTRU in the L1-RSRP reporting configuration information.

[0112] The WTRU may determine, select, or decide the number of reference beams based on the values of beam measurements (e.g, L1 -RSRP measurements). The WTRU may decide to use one reference beam (e.g., reference CSI-RS resource) if the maximum difference between the highest beam measurement (e.g., L1-RSRP) value and all the other beam measurement values (e.g., L1 -RSRP values) are less than a certain threshold (e.g., a threshold configured by the gNB via RRC signaling or MAC-CE indication). If the aforementioned difference exceeds the threshold, (where the number of reference beams > 1 ) reference beams (e.g, reference CSI-RS resources) may be selected.

[0113] The WTRU may determine, select, or decide the number of reference beams based on the use case of beam measurement reporting. For example, the WTRU may determine a first number of reference beams if the beam reporting is used for a first use case and the WTRU may determine a second number of reference beams if the beam reporting is used for a second use case, and so forth. The use case may be at least one of following: AI/ML model use cases (e.g, online/offline training, inference, fine-tuning, etc.); life cycle management use cases (e.g, model performance monitoring, model switching, model activation/deactivation, etc.); or AI/ML functionalities (e.g, beam prediction in time domain, beam prediction in spatial domain).

[0114] Examples of beam measurement reporting with a single reference beam are provided herein. The WTRU may report the single beam measurement value (e.g, L1 -RSRP value) of a single reference beam, which may have an associated beam index ID. This beam may be associated with a beam resource (e.g, CSI-RS resource) in the beam resource set (e.g, CSI-RS resource set) that may be (e.g, may be required to be) reported.

[0115] The reference beam or reference signal (e.g, CSI-RS resource, CSI-RS identity, SSB identity, etc.) may be selected or determined based on the beam measurement value (e.g, L1 -RSRP value) (e.g, highest, median, lowest) associated with the beam reference signal. Hereafter, beam reference signal, CSI- RS, SS/PBCH block, SSB, and beam may be interchangeably used. [0116] In examples, the reference beam (e.g., CSI -RS resource) may be selected as the beam (e.g., CSI-RS resource) with the maximum beam measurement (e.g., maximum measured L1 -RSRP value) in the CSI-RS resource set.

[0117] In examples, the reference beam (CSI-RS resource) may be the beam (CSI-RS resource) with the median beam measurement (e.g., median L1-RSRP value) within the CSI-RS resource set.

[0118] In examples, the WTRU may consider a reference beam (CSI-RS resource) based on an explicit indication from the gNB. The aforementioned indication may (e.g., may also) be implicit (e.g., a beam corresponding to the lowest or highest CRI).

[0119] FIG. 5 illustrates an example of differential L1 -RSRP using a maximum L1-RSRP beam as the reference beam. FIG. 6 illustrates an example of differential L1 -RSRP using the adjacent beam as the reference beam. In order to calculate the differential beam measurements (e.g., differential L1 -RSRP values) of the remaining beams (e.g., CSI-RS resources) in the beam resource set (e.g., CSI-RS resource set), the WTRU may receive configuration information (e.g., from a gNB, to confirm the reference for calculating differential beam measurements (e.g., differential L1 -RSRP values)). The WTRU may be indicated by the gNB (e.g., or may select) to calculate differential beam measurement (e.g., differential L1 - RSRP values) of the remaining beams (e.g., CSI-RS resources) by comparing all their beam measurements (e.g., L1 -RSRP values) to the beam measurement (e.g., L1 -RSRP value) of the reference beam (e.g., reference CSI-RS resource) (e.g., as shown in FIG .5). The differential beam measurements (e.g., differential L1-RSRP values) of the remaining beams (e.g., CSI-RS resources) may be obtained by comparing each remaining beam (e.g., CSI-RS resource) to the adjacent beam (e.g., CSI-RS resource) iteratively starting from the beam (e.g., CSI-RS resource) adjacent to the reference beam (e.g., reference CSI-RS resource) (e.g., as shown in FIG. 6).

[0120] If obtaining (e.g., after obtaining) a differential beam measurement (e.g., differential L1 -RSRP values) calculation configuration, the WTRU may calculate the differential beam measurements (e.g., differential L1 -RSRP values) of the remaining beams (e.g., CSI-RS resources) in the beam resource set (e.g., CSI-RS resource set) (e.g., of all the beams in the beam resource set except the reference beam). The WTRU may report the differential beam measurements (e.g., differential L1 -RSRP values) to the gNB. [0121] Examples of beam measurement reporting with more than one reference beam are provided herein. The WTRU may be configured with CSI-RS resources and/or SS/PBCH block resources for the purpose of beam measurement (e.g., L1 -RSRP measurement) and reporting. For example, the WTRU may be configured with CSI-RS resource setting up to X CSI-RS resource sets having up to Y resources within sets (e.g., each set). The total number of different CSI-RS resources over resource sets (e.g., all resource sets) may be configured to be less than Z. In examples, the values of X, Y and Z may be pre-defined or preconfigured to be 16, 64 and 128 respectively. In examples, the values of X, Y and Z may be configured to be greater than 16, 64 and 128 respectively.

[0122] WTRU behaviors may be defined or configured such that the overhead of beam measurement (e.g., L1-RSRP) reporting associated with CSI-RS resources within a CSI-RS resource set is minimized. The WTRU may be configured with a beam measurement reporting with a number of reference beams (e.g., the value N). The value of N may be predefined or preconfigured. In examples, the value of N may be greater than 1. In examples, the value of N may be configured by the network. In examples, the value of N may be determined by the WTRU.

[0123] For example, the WTRU may be configured to determine the value of N within a range configured by the network. The WTRU may be configured to determine the value of N such that one or more preconfigured conditions are satisfied. For example, the criteria may be associated with minimizing the overhead associated with L1-RSRP reporting. For example, the criteria may be associated with minimizing the quantization loss if differential L1-RSRP reporting is applied. For example, the criteria may be defined such that the WTRU minimizes the quantization loss (e.g., given the payload size of the PUCCH and/or a PUSCH that carries the L1-RSRP reporting). For example, the WTRU may determine the value of N implicitly based on the number of CSI-RS resources within CSI-RS resource set. For example, the WTRU may determine the value of N based on the number of beams above a preconfigured L1 -RSRP threshold. The WTRU may determine the value of N based on a range of L1-RSRP measurement values. For example, if the range of L1 -RSRP measurement values is narrower than a threshold (e.g., a threshold configured by the gNB via RRC signaling or MAC-CE indication), a first N value may be used or determined. For example, if the range of L1 -RSRP measurement values is equal to or wider than the threshold, a second N value may be used or determined.

[0124] The number of reference beams may be determined based on the number of beam reporting groups. For example, the CSI-RS resources within a CSI-RS resource set may be grouped into a number of subsets. The number of subsets (e.g., each subset) may include one or more CSI-RS resources which is not overlapped with one or more CSI-RS resources in another subset. The WTRU may determine a reference beam in the subsets (e.g., each subset (or beam group)). [0125] The beam group information may be configured by a gNB (e.g., number of beam groups, information of CSI-RS resources for each beam group, etc.). The WTRU may report preferred beam grouping information.

[0126] The notion of a reference beam may be used for differential beam measurement reporting (e.g., differential L1 -RSRP reporting). The WTRU may be configured with rules to select a reference beam within a CSI-RS resource subset. For example, the rules may include one or more of the following: the beam with highest beam measurement (e.g., highest L1-RSRP) within the CSI-RS resource subset; the beam with median beam measurement (e.g., median L1-RSRP) within the CSI-RS resource subset; the beam if chosen as the reference beam that results in the lowest quantization loss; or the beam if chosen as reference beam that results in the least overhead. The reference beam may be associated with the beam index explicitly indicated by the gNB. The beam index may be associated with the beam position within the CSI-RS resource set configuration (e.g., highest, middle or lowest beam index). The differential beam measurement (e.g., differential L1-RSRP) of a non-reference beam may be derived based on the difference between the beam measurement (e.g., L1-RSRP) of the reference beam and the beam measurement of non-reference beam. The differential beam measurement of non-reference beam may be derived based on the difference between the beam measurement of non-reference beam and the beam measurement of immediately adjacent beam.

[0127] The WTRU may indicate the reference beam explicitly by including an explicit identity associated with the reference beam. For example, the WTRU may include in the L1-RSRP report, the CRI or SSBRI (e.g., depending on whether the indicated reference beam is associated with CSI-RS or SSB) associated with reference beam. The WTRU may apply a first type of reporting format for the reference beam and a second type of reporting format for the non-reference beam (e.g., beams other than reference beam). For example, the first type of reporting may correspond to reporting an m-bit value mapped to a first L1 -RSRP value range with a first configured step size. For example, the WTRU may report a L1-RSRP value of reference beam defined by 7-bit value in the range [-140, -44] dBm with 1 dB step size. A second type of reporting may correspond to reporting a differential L1 -RSRP with respect to the L1-RSRP of a reference beam. The reporting may correspond to n-bit value within a second L1 -RSRP range with a second configured step size. For example, the WTRU may report differential L1-RSRP value of non-reference beam defined by 4-bit value in the range [-140, -44] dBm with 2 dB step size.

[0128] The WTRU may be configured with beam measurement reporting such that the beam measurement reporting (e.g., L1 -RSRP reporting) is based on partitioning of CSI-RS resource sets (e.g., each CSI -RS resource set) into a number of CSI-RS subsets. The WTRU may be configured to partition the subsets such that at least one reference beam may be present in the subsets (e.g, in each subset). In examples, the number of CSI-RS subsets may be predefined or preconfigured. In examples, the number of CSI-RS subsets may be greater than 1 . In examples, the number of CSI-RS subsets may be configured by the network. In examples, the number of CSI-RS subsets may be determined by the WTRU.

[0129] For example, the WTRU may be configured to determine the a number of CSI-RS subsets within a range configured by the network. The WTRU may be configured to determine the number of CSI-RS subsets such that one or more preconfigured conditions are satisfied. For example, the criteria may be associated with minimizing the overhead associated with L1 -RSRP reporting. For example, the criteria may be associated with minimizing the quantization loss if differential L1-RSRP reporting is applied. For example, the criteria may be defined such that the WTRU minimizes the quantization loss given the payload size of the PUCCH and/or PUSCH that carries the L1 -RSRP reporting. For example, the WTRU may determine the number of CSI-RS subsets implicitly based on the number of CSI-RS resources within CSI-RS resource set. For example, the WTRU may determine the number of CSI-RS subsets based on the number of beams above a preconfigured L1 -RSRP threshold.

[0130] In examples, a WTRU may partition beam resources of a resource set based on beam ID (e.g., CRI) into a configured number (Z) of partitions. If a number of beams in the CSI-RS resource set (P) is divisible by Z, the partitions (e.g., each partition) may have P/Z beams. The first partition may include beams with first P beam indices (e.g., 0, 1 , ..., P-1). The second partition may include beams (P, P+1, ..., 2P-1) and so forth. If P is not divisible by N, one of the partitions (e.g., first, or Nth partition) may have floor(Z/P)- iodulo(Z, P) beams. The remaining Z-1 partitions may have floor(PZZ) beams. Here floor(.) is the floor function and modulo(.,.) is the modulo operation. One of the partitions (e.g., the first or Nth partition) may have P-ceiling(P/Z)*(Z-1) beams. Here, ceiling(.) is the ceiling function. The remaining N-1 partitions may have ceiling (P/Z) beams.

[0131] In examples, the size of the CSI-RS resource subset may be fixed for the CSI-RS resource sets (e.g, all CSI-RS resource sets). In examples, the size of the CSI-RS resource subset may be specific to CSI-RS resource set. For example, all the CSI-RS resource subsets within a CSI-RS resource set may be of same size. For example, the size of the CSI-RS resource subset may be different or the same across CSI-RS resource sets. The WTRU may be configured to determine the size of the CSI-RS resource subset to satisfy a preconfigured criterion. Such a criteria may be similar to the criteria configured for the determination of number of CSI-RS resource subsets. In examples, the size of the CSI-RS resource subset may be based on the difference between a max L1-RSRP and a min-L1-RSRP of beams within the subset. The difference between the max and min L1 -RSRP in a CSI-RS resource subset may be below a certain preconfigured threshold. In examples, the size of the CSI-RS resource subset may depend on the relative L1-RSRP of other reference beams within the CSI-RS resource set.

[0132] In examples, a WTRU may first determine the number of reference beams and may (e.g., may then) determine the size of the CSI-RS resource subset associated with reference beams (e.g., each reference beam). The WTRU (e.g., as a result) may derive the number of CSI-RS resource subsets within the CSI-RS resource set. In examples, the WTRU may first determine the number of CSI-RS resource subsets as a result of the number of CSI-RS subsets within a CSI-RS resource set. The WTRU may be configured with a one-to-one relation between a CSI-RS resource subset and a reference beam. In examples, the WTRU may be configured to determine one reference beam per CSI-RS resource subset. In examples, the WTRU may be configured to jointly determine the reference beam(s), CSI-RS resource subset size, and the number of CSI-RS resource subsets such that one or more preconfigured criteria (e.g., as described herein) are met.

[0133] FIG. 7 illustrates an example of differential L1 -RSRP with two reference beams. Examples of a realization of differential L1-RSRP reporting with multiple reference beams and/or CSI-RS resource subsets are provided herein (e.g., as shown in FIG. 7). FIG. 7 shows L1-RSRP of 16 beams indexed by 1-16 (e.g., possibly associated with 16 CSI-RS resources in a CSI-RS resource set). The WTRU may be configured (e.g., as described herein) to partition the CSI-RS resources within the resource set into two CSI-RS resource subsets - the blue CSI-RS resource subset and red CSI-RS resource subset, each including 8 LI-RSRPs. For the purposes of L1-RSRP reporting, the WTRU may determine a reference beam within the CSI-RS resource subsets (e.g., each CSI-RS resource subset). The WTRU may select the reference beam corresponding to the highest L1-RSRP within the CSI-RS resource subset. In the blue CSI-RS resource subset, the reference beam is the beam index 4, thus the WTRU includes L1-RSRP and the CRI associated with beam index 4 in the CSI report. The WTRU may (e.g., may also) include differential L1 - RSRP of other beams within the blue CSI-RS resource subset. The differential L1-RSRP may be calculated using the difference between the L1-RSRP of reference beam and the L1-RSRP of non-reference beam. In the red CSI-RS subset, the reference beam is the beam index 12, thus the WTRU includes L1-RSRP and CRI associated with beam index 12. The WTRU may (e.g., may also) include differential L1-RSRP of other beams within the red CSI-RS resource subset. The differential L1-RSRP may be calculated using the difference between the L1-RSRP of reference beam and the L1-RSRP of non-reference beam. Within the CSI report, the WTRU may indicate the identity of non-reference beam using implicit identity based on order of L1-RSRP within the CSI-report. For example, the WTRU may include the L1 -RSRP of beams in the order of CSI-RS resources within the CSI-RS resource subset.

[0134] A WTRU may select a set of reference beams (e.g., which may be identified by a set of reference signal (RS) resources associated with the set of reference beams) for reporting beam measurements (e.g., L1-RSRP). The WTRU may select (e.g., may also select) a set of associated adjacent beams (e.g., a set of RS resources with adjacent indices) for performing and reporting relative measurements (e.g., differential L1-RSRP with respect to the reference beams (e.g., RS resources)). The associated adjacent beams (e.g., RS resources with adjacent indices) may be selected using the reference beam (e.g., RS resource) and a configured or default order of beam indices (e.g., RS indices). This order may be determined based on an assumption or observation that beams with similar elevation and azimuth angles are correlated. The correlation between beams may be used to reduce reporting overhead.

[0135] A WTRU may be configured (e.g., may receive confirmation information) with differential (e.g., differential L1 -RSRP) RS resource measurement reporting. The configuration information may include at least one: an RS resource set, a preconfigured threshold (e.g., a measurement range threshold (e.g., the difference between the maximum and minimum measurement values)), or a window size. The RS resource set may include RS resources.

[0136] The WTRU may receive an indication or configuration information that RS resources in the configured RS resource set are ordered (e.g., such that RS resources (e.g., to use for beam measurements) within the RS resource set (e.g., with adjacent indices) are correlated). The indication or configuration information may be received in a message (e.g., via RRC signaling, or the WTRU may determine such information based on a default configuration).

[0137] The WTRU may perform beam measurements (e.g., L1 -RSRP) on RS resources of a configured RS resource set.

[0138] In examples, the WTRU may determine a number (N) and identity of reference beam(s), for example based on the beam measurements and/or gNB configuration (e.g., based on comparing the beam measurements to the preconfigured threshold (e.g., the measurement range threshold), a number of RS resources in a configured RS resource set, or a number of RS resources in a window size).

[0139] The WTRU may report RS resource measurements on RS resources with a number of reference beams (e.g., with one reference beam or more than one reference beam). The WTRU may determine the RS resources within the RS resource set are in a number of RS resource subsets (e.g., which is equal to the number of reference beams).

[0140] If N > 1 (e.g., the number of the reference beams is greater than one), the WTRU may partition the RS resources in the configured RS resource set to a number of RS resource subsets.

[0141] If N = 1 (e.g., the number of the reference beams is one), the WTRU may consider the RS resources in the configured RS resource set to be in a single (e.g., first) subset.

[0142] The WTRU may select one RS resource (e.g., one RS resource from each subset) (denoted by6_fc£, i e {1, 2. }).

[0143] The WTRU may select the RS resource b_ki based on measurements (e.g., the RS resource with the highest measurement in the subset of RS resources, or the RS resource with a median measurement in the subset of RS resources).

[0144] In examples, the WTRU may determine differential RS resource measurements as a measurement of b_ki as the reference for differential measurement computation of other RS resources in the subset. In examples, the WTRU may determine differential RS resource measurements as a measurement of b_ki as the reference for differential measurement computation of a first subset of up to two RS resources with adjacent indices (e.g., based on CRI); a measurement of the first set of up to two RS resources as the reference for differential measurement computation of a second set of up to two RS resources with adjacent indices, and so on until differential measurements are computed for all nonreference RS resources in the subset.

[0145] For the subsets (e.g., for each subset) of RS resources, the WTRU may report measurement(s) (e.g., L1-RSRP) of the reference RS resource(s) and its index (e.g., CRI) along with differential measurement(s) (e.g., differential L1 -RSRP) of the remaining RS resource(s) in subsets (e.g., in each subset).

[0146] Examples of reducing beam reporting overhead via spatial and temporal-domain compression are provided herein. Examples of sparse beam reporting are provided herein. Examples of initiating beam measurements for model inference or model training are provided herein.

[0147] A WTRU may receive configuration or indication to report beam measurements (e.g., L1 -RSRP) associated with one or more beam resource sets over one or more measurement instances. [0148] The WTRU may receive a trigger (e.g., via a DCI) activating a semi-persistent CSI report. The triggered CSI report configuration may be associated with a CSI resource configuration with a resource type semi-persistent or periodic, and report quantities CRI and L1 -RSRP.

[0149] The WTRU may indicate the gNB the potential need of beam measurements (e.g., new beam measurements) for model inference or model training. The WTRU may determine the potential need for beam measurements (e.g., updated beam measurements) based on the detection of one or more of the following events. If one or more of the events is detected, the WTRU may report the detection of one or more events as assistance information for the gNB to determine the updated beam measurements.

[0150] The events that initiate the transmission of assistance information may include one or more of following: a change in the direction of movement; a change in the speed (e.g, exceeding the speed of the WTRU beyond a preconfigured threshold, or changing the speed is beyond a preconfigured threshold); a switching antenna panel; a change in level of interference beyond a preconfigured threshold (e.g, the threshold may be configured via one or more of an RRC signaling, an MAC-CE indication, or a DCI indication); a change in an LoS condition (e.g, LoS to non-LoS or non-LoS to LoS); or a detection of restriction based on an EIRP condition (e.g, detection of a local object that restrict the EIRP below a preconfigured threshold by the gNB).

[0151] A WTRU may report assistance information to the gNB based on one or combination of the following examples.

[0152] A WTRU may be configured with a preamble. If of one or more events within a preconfigured time duration (e.g, configured time duration via RRC signaling) is detected, the WTRU may transmit the preamble.

[0153] A WTRU may be configured with two preambles. The WTRU may transmit the first preamble (e.g, if one event is detected within a preconfigured time duration by the gNB (e.g, configured time duration via RRC signaling)). The WTRU may transmit the second preamble (e.g, if more than one event is detected within the preconfigured time duration).

[0154] A WTRU may be configured with a set of preambles. Preamble resources (e.g, each preamble resource) may be associated with one or more events. If one or more events within a preconfigured time duration (e.g, time duration preconfigured via RRC signaling) are detected, the WTRU may transmit a preamble associated with the one or more events. [0155] A WTRU may transmit a one bit indication to a gNB (e.g., via PUCCH or MAC-CE) if one or more events within a preconfigured time duration are detected (e.g., time duration configured via RRC signaling). [0156] A WTRU may transmit a set of bits to the gNB (e.g., via PUCCH or MAC-CE) if one or more events within a preconfigured time duration are detected (e.g., time duration configured via RRC signaling). The bits (e.g., each bit in the set of bits) may be associated with an event. Bit value ‘1’ may indicate the occurrence of the associated event while bit value set to ‘0’ may indicate nonoccurrence of the associated event.

[0157] The WTRU may receive a request for reporting a beam measurement associated with one or more beam resource sets from the gNB (e.g., based on the reported supporting information).

[0158] The WTRU may receive an indication of UL resources (e.g., via scheduling PUSCH and/or PUCCH) to transmit supporting information (e.g., additional supporting information) to evaluate the need for beam measurements (e.g., new beam measurements). In examples, if one or more events within a preconfigured time duration are detected, the WTRU may transmit a preconfigured preamble. In response to the transmitted preamble, the WTRU may receive a UL grant for scheduling one or more PUSCHs in which the WTRU may transmit a MAC-CE indicating the occurrence of event(s) (e.g., each event) within a preconfigured time duration (e.g., as a bit map). The WTRU may (e.g., may also) indicate the number of occurrences for event(s) (e.g., each event) within the time interval.

[0159] Examples of beam measurement reporting based on time-domain differential beam measurements are provided herein. A WTRU may receive a configuration (e.g., configuration information) and/or an indication to report beam measurements (e.g., L1 -RSRP) associated with one or more beam resource sets over more than one measurement instance. The WTRU may report beam measurement of the first measurement instance by using at least one of the examples described herein. Beam measurements (e.g., L1 -RSRP) of one or more reference beams and their beam IDs (e.g., CRIs) may be reported along with differential beam measurements (e.g., differential L1-RSRP) of the rest of the beams in the beam resource set.

[0160] In response to a request for beam report associated with a beam resource set, for the first measurement reporting instance, a WTRU may report the L1 -RSRP of the beam with highest L1 -RSRP and differential L1 -RSRP of the remaining beams in the resource set using the highest L1-RSRP beam as a reference. The WTRU may (e.g., may also) report the beam ID (e.g., CRI) of the beam corresponding to the highest L1-RSRP. [0161] For the subsequent reporting instances, for beam(s) (e.g., each beam) in the beam resource set, the WTRU may report time-domain differential L1-RSRP. The time domain differential L1-RSRP may be the difference between the L1 -RSRP of a beam at a measurement instance and a reference time instance. A WTRU may be configured with and/or indicated by at least one of the following as the reference resource measurement instance: a first reporting instance as the refence measurement instance; the immediate past measurement instance as the reference measurement instance; or any indicated measurement instance by the gNB as the reference measurement instance.

[0162] The WTRU may select a reference measurement instance and may indicate its selection to the gNB via a PUCCH or MAC-CE signaling. The WTRU may determine the maximum time-domain differential L1-RSRPs of the beams (e.g., all the beams) in the beam resources set. The WTRU may (e.g., may then) select the first reporting instance as the reference if such selection may result the maximum time-domain differential L1 -RSRP below a preconfigured threshold by the gNB. If the maximum time-domain differential L1-RSRP exceeds the threshold, the WTRU may choose the immediate past reporting instance as the reference measurement instance.

[0163] Examples of beam measurement reporting based on sparse reporting are provided herein. Examples of activation or deactivation of sparse reporting are provided herein. A WTRU may receive configuration information or an indication from the gNB for activation or deactivation of sparse reporting. [0164] FIG. 8 illustrates an example of beam reporting over consecutive measurement instances with sparse reporting. If sparse reporting is activated, a WTRU may report beam measurements of a subset of beams out of the beams (e.g., all the beams) associated with a beam resource set (e.g., as shown in FIG. 8).

[0165] The WTRU may explicitly indicate to activate sparse beam reporting via a DCI indication or an MAC-CE signaling (e.g., 1 bit indication, bit value ‘1’ for activation, and bit value ‘0’ for deactivation).

[0166] The WTRU may be configured with sparse beam reporting. The activation of sparse beam reporting may be subject to WTRU determination based on beam measurements (e.g., L1 -RSRP) over k (e.g., k = 2) number of measurement instances (e.g., k initial beam measurement instances), k may be configured via an RRC signaling, by an MAC-CE indication, or a DCI indication.

[0167] In example configurations, if the magnitude of the maximum and/or average of the magnitude of time-domain differential L1-RSRPs of beams associated with a resource set over k measurement instances is below a preconfigured sparse reporting activation threshold by the gNB (e.g., via RRC signaling or MAC- CE indication), the WTRU may determine to activate sparse beam reporting for the resource set.

[0168] If k >3, for beam(s) (e.g., each beam), the WTRU may consider one or multiple time-domain differential L1 -RSRP measurements based on one of the following. The WTRU may consider multiple or single time-domain differential L1-RSRP measurement for beam(s) (e.g., each beam) based on the selected option (e.g., determined via one or more of DCI, MAC CE and RRC configuration).

[0169] For a beam, multiple time-domain differential L1 -RSRP measurements over k > 3 measurement instances may be computed as, L1-RSRP at 2nd measurement instance - L1-RSRP at 1st measurement instance, L1 -RSRP at 3rd measurement instance - L1-RSRP at 2nd measurement instance, ..., L1-RSRP at nth measurement instance - L1-RSRP at (k-1 )th measurement instance.

[0170] For a beam, a single time-domain differential L1 -RSRP measurements over k > 3 measurement instances may be computed as, L1-RSRP at nth measurement instance - L1-RSRP at 1st measurement instance.

[0171] The WTRU may indicate the activation of sparse reporting to the gNB (e.g., as 1 bit indication via a PUCCH or an MAC-CE).

[0172] In example configurations, if the magnitude of (e.g., all the) time-domain differential measurements (e.g., L1-RSRPs) of a number of beams associated with an RS resource set (e.g., over N measurement instances) are below a preconfigured sparse reporting activation threshold (e.g., configured by the gNB), the WTRU may determine to activate sparse beam reporting for the resource set. The WTRU may indicate the activation of sparse reporting to the gNB (e.g., as 1 bit indication via PUCCH or MAC-CE).

[0173] In example configurations, if the number of beams in a beam resource set with a magnitude of time-domain differential L1-RSRP below a preconfigured sparse reporting activation threshold over N measurement instances is larger than a preconfigured number (e.g., configured by the gNB), the WTRU may activate sparse beam reporting. The WTRU may indicate the activation of sparse reporting to the gNB (e.g., as 1 bit indication via a PUCCH or an MAC-CE).

[0174] Activation or deactivation of sparse reporting may be determined by the beam measurement estimated (e.g., L1-RSRP) by the WTRU for a UL beam associated with a PUSCH or PUCCH resources a CSI report is sent on. If the estimated beam measurement is lower (higher) than a preconfigured threshold by the gNB, the WTRU may deactivate (activate) sparse reporting to avoid a loss of CSI reports due to lower UL channel quality. The WTRU may use DL beam reciprocity to estimate the beam measurements of UL beams associated with a PUSCH or a PUCCH based on DL beam measurements.

[0175] The WTRU may receive an indication for activation of sparse reporting implicitly based on the index of the report configuration indication. For example, the WTRU may be RRC configured with a list of beam measurement report configurations (e.g, CSI-ReportConfig) associated with sparse reporting. If receiving a request for a CSI report associated with a sparse reporting configured CSI report configuration, the WTRU may activate sparse reporting.

[0176] The WTRU may determine full reporting (e.g., reporting L1 -RSRPs of all CSI-RS resources in a CSI-RS resource set) or sparse reporting (e.g., reporting L1 -RSRP of a subset of CSI-RS resources in a CSI-RS resource set) based on one or more of following: AI/ML model performance (e.g, CSI prediction accuracy); an AI/ML model use case (e.g, online, or offline training, inference, monitoring, etc.); a time resource (e.g, slot number, frame number, etc.); a size of the reporting resource (e.g, number of bits for the reporting resource configured or determined); or one or more system parameters (e.g, waveform, subcarrier spacing, bandwidth, cell-ID, CP length, bandwidth part identity, etc.).

[0177] Sparse reporting may be interchangeably used with beam group reporting, beam subset reporting, multi-beam reporting, and reduced overhead beam reporting.

[0178] Examples of determining a subset of beams for sparse reporting in measurement instances (e.g, each measurement instance) are provided herein. If sparse reporting is activated, a WTRU may determine a subset of beams to report beam measurements at sparse reporting instances (e.g, each sparse reporting instance) based on one or more of the following.

[0179] The WTRU may be configured with a beam subset selection pattern by the gNB via RRC signaling. For example, at first sparse reporting instance, beam measurements of beams with odd resource IDs (e.g, CRI) may be reported. Beam measurements of beams with even resource IDs (e.g, CRI) may be reported (e.g, in the subsequent reporting instance). This pattern may continue until (e.g, all the) sparse beam reporting instances are completed.

[0180] The WTRU may be configured (e.g, via RRC signaling) with more than one beam subset selection patterns. For example, the WTRU may receive an indication for selecting one pattern out of configured set of patterns for a CSI report configuration by the gNB (e.g, via DCI indication or MAC-CE signaling). [0181] The WTRU may be implicitly indicated a pattern to be used with sparse beam reporting based on CSI report configuration. For example, beam subset selection for sparse reporting may be configured as a parameter in CSI report configuration. Based on the associated CSI report configuration in the for CSI report, the WTRU may determine the beam selection pattern for sparse reporting. For example, beam selection for sparse reporting may be configured as a parameter in a beam resource set (e.g., CSI - ResourceConfig) associated with a CSI report configuration. Based on the beam resource set associated with the CSI report configuration for CSI report, the WTRU may determine the beam selection pattern for sparse reporting.

[0182] The WTRU may determine a subset of beams to be reported at sparse reporting instances (e.g., each sparse reporting instance) based on a variation of beam measurements with time. The WTRU may report the selected subset of beams to the network node (e.g., gNB) along with the beam measurements. [0183] The WTRU may estimate the time-domain differential L1 -RSRP based on beam measurements and select beams with the magnitude of time-domain differential L1-RSRP exceeding a sparse reporting beam selection threshold preconfigured by gNB (e.g., via RRC signaling or MAC-CE indication). The WTRU may indicate the selected beam subset for measurement instances (e.g., each measurement instance) associated with sparse reporting to the gNB (e.g., by reporting beam subset selection as a bitmap in the beam report).

[0184] The WTRU may determine a subset of beams to be reported based on a time index associated with beam measurement and/or beam reporting. The time index may be at least one of a slot index, a radio frame index, or a symbol index.

[0185] FIG. 9 illustrates an example of beam measurement reporting with sparse reporting. Examples of WTRUs reporting beam measurements with sparse reporting are provided herein. If a WTRU is configured, indicated, or determined to perform beam measurement reporting with sparse reporting for a beam resource set, the WTRU may report beam measurements using at least one or combination of the following.

[0186] For the initial k (e.g., k = 1) measurement instances configured by the gNB (e.g., via RRC signaling), a WTRU may report beam measurements of the beams (e.g., all the beams) in the resource set (e.g., L1 -RSRP) by using one or more of the examples provided herein. For example, a WTRU may report L1-RSRP measurements of a beam resource set for the first measurement instance (e.g., k = 1) by reporting the beam ID (e.g., CRI) of the beam with the highest L1-RSRP and differential L1 -RSRP of rest of the beams.

[0187] For the measurement instances after kth instance, the WTRU may select a subset of beams to be reported based on one or more of the examples provided herein. For example, in the first sparse reporting measurement instance, the WTRU may report L1-RSRP of beams with odd beam IDs (e.g., odd CRIs). The WTRU may report beam measurements of beams with even beam IDs (e.g., CRIs) (e.g., in the subsequence measurement instance). This beam subset selection procedure for sparse reporting may be continued until all the measurement instances corresponding to sparse reporting are completed.

[0188] For the measurement instances after the kth instance, the WTRU may report beam measurements of a subset of selected beams in the resource set for measurement instances (e.g., each measurement instance) by reporting beam measurements by using one or more examples provided herein. For example, a WTRU may report a beam measurement of a selected subset of beams by reporting the beam ID (e.g., CRI) of the beam corresponding to the highest L1 -RSRP in the selected subset and differential L1 -RSRP of rest of the beams in the selected subset.

[0189] For the measurement instances after the kth instance, the WTRU may report beam measurements of a subset of selected beams in the resource set for measurement instances (e.g., each measurement instance) by reporting time-domain differential beam measurements. If time-domain differential beam measurements (e.g., time-domain differential L1-RSRP) are computed for a selected subset of beams, one or more of the following may be used to determine the reference beam measurement for beam(s) (e.g., each beam) (e.g., as shown in FIG. 9): the most recent beam measurement reported for the same beam resource; or a beam measurement reported for the same beam at any initial k measurement instance where beam measurements of the beams (e.g., all the beams) are reported (e.g., the beam measurement reported for the same beam at kth initial measurement instance).

[0190] Examples for selecting representative beams and time instances for beam reporting are provided herein. Examples for selecting a subset of beam for beam measurement and reporting are provided herein. The WTRU may perform measurements on one or more beam resources (e.g., CSI-RS resources) and derive one or more CSI parameters. In examples, during the beam selection, the WTRU may measure and derive received power and report (e.g., CRI-RSRP/L1-RSRP) for one or more beam resources (e.g., up to N CRI-RSRP/L1 -RSRP with highest RSRP). In examples, the WTRU may determine a CRI (e.g., based on a priority such as CQI, RSRP, and so forth) from the supported or configured set of CRI values and report the CRI along with one or more CSI parameters for the determined CRI. The WTRU may measure and derive one or more CSI parameters for the determined CRI (e.g., conditioned on the reported CRI).

[0191] A WTRU may determine, receive, and/or be provided with one or more of a configuration, indication, and/or activation trigger (e.g., from a gNB) to dynamically (e.g., adaptive) determine, select, and/or identify a subset of beam resources. The WTRU may use the indication and/or configuration to determine the beam resources to be reported as part of the determined and/or selected subset of the beams. The configuration (e.g., configuration information) and/or indication may include one or more of the following: a number of measurement instances (e.g., the WTRU may receive and/or determine the number of measurement instances that the WTRU may perform for beam subset selection); or beam selection criteria (e.g., the WTRU may receive one or more parameters to determine if a beam resource should be considered in a respective beam subset selection). One or more of the following may apply: a maximum differential beam measurement (e.g., differential L1-RSRP) (e.g., the WTRU may determine to include a beam resource in a beam subset selection, if the measured and/or determined received power (e.g., L1 - RSRP) compared to a reference maximum received power (e.g., for a selected adjacent beam) is within a first threshold); or an average differential beam measurement (e.g., average differential L1 -RSRP) (e.g., the WTRU may determine to include a beam resource in a beam subset selection, if the measured and/or determined received power (e.g., L1 -RSRP) compared to a reference average power (e.g., for a selected adjacent beam) is within a second threshold).

[0192] The WTRU may be configured or determined to report the beam resources that the WTRU has selected for the beam subset. In examples, the WTRU may report the indexes (e.g., CRI) corresponding to the selected beam resources. In examples, the WTRU may report the selected beam indexes based on a bitmap, where a first value (e.g., one (1)) may indicate that the corresponding beam was selected, and a second value in the bitmap (e.g., zero (1)) may indicate that the corresponding beam was not selected.

[0193] The WTRU may report the measured parameters for one or more of the selected beam resources in the selected subset of the beams. In examples, the WTRU may report the received power (e.g., L1- RSRP, L1-SINR, RSSI, and so forth) for the selected subset of the beams. In examples, the WTRU may report the absolute value for a first beam (e.g., as a reference beam) (e.g., beam with the highest L1 - RSRP). The WTRU may report differential values (e.g., differential L1-RSRP) for the other beam resources and based on the reported reference beam.

[0194] Examples of selecting representative beams and time instances for beam reporting are provided herein. The WTRU may select one beam to represent beam measurements of a few adjacent beams (e.g., based on CRI) if all beams have similar beam measurements. The WTRU may report beam measurements of a selected set of beams and may indicate the selected set of beams to the gNB. The WTRU may report beam measurements at selected measurement instances if the variation of beam measurement(s) over time (e.g., time-domain differential L1 -RSRP) is low.

[0195] The WTRU may receive an indication to measure and report beam measurements of one or more beam resource sets by the gNB. The WTRU may receive an indication from the gNB to activate an adaptive selection of a subset of beams for reporting beam measurements. The WTRU may select a subset of beams based on a preconfigured selection rule (e.g., if a differential L1-RSRP based on adjacent beam with lower CRI as reference < threshold, this beam is dropped from the beam report. A dropped beam may be not considered as a reference. This process may continue until a beam may be found that satisfies the condition differential L1-RSRP with lower CRI as reference > threshold. The reference beam may be switched to newly found beam. The process may be continued until all the beams in a beam resource set are completed.)

[0196] The WTRU may report selected set of beams to the gNB (e.g., in a bitmap). The WTRU may report beam measurements of a selected subset of beams to the gNB (e.g., the WTRU may report an absolute L1 -RSRP of the highest L1-RSRP beam and a differential L1-RSRP of each beam considering the subset of beams selected.)

[0197] Examples of reporting a subset of beams are provided herein. The WTRU may maintain and report measurements for subsets of beams. The measurement types reported for a subset of beams may include at least one of: RSRP, RSRQ, RSSI, SINR, CQI, Rl, PMI, AoA, AoD, Doppler spread, Doppler shift, delay spread, average delay, or channel occupancy. A WTRU may determine the members (e.g., beams) of a subset of beams to be measured and/or reported by at least one of: an ID of the subset of beams; measurement values; or a configuration from a network node (e.g., gNB).

[0198] For the ID of the subset of beams, a WTRU may be configured with, or determine an ID associated with, a subset of beams. The beams associated with a subset may be determined as a function of the ID of the subset or a beam index or a measurement resource index associated with a beam.

[0199] For measurement values, a WTRU may determine a subset of beams as the beams (e.g., all the beams) of which a measurement is within a threshold value. In examples, a WTRU may determine a subset of beams as N beams of which the measurement is closest (e.g., where N may be configurable). The measurement used may include at least one of: RSRP, RSRQ, RSSI, SINR, CQI, Rl, PMI, AoA, AoD, Doppler spread, Doppler shift, delay spread, average delay, or channel occupancy.

[0200] For configuration from the network node (e.g., gNB), the WTRU may be configured with subsets of beams in an RRC configuration or a DCI indication or an MAC CE indication.

[0201] A WTRU may report an identity of beams (e.g., all beams) in a subset of beams (e.g., if the WTRU determines (or dynamically determines) the beams that include a subset of beams).

[0202] Examples of measurement report for a subset of beams are provided herein. The WTRU may determine a measurement associated with a subset of beams. The reported measurement may include one or more measurement types listed herein, for one or more beams in the subset of beams. The reported measurement may be determined from one or more beams in the subset of beams. For example, the reported measurement may be at least one of: maximum measurement (e.g., a maximum value among measurements) associated with a beam in the subset of beam; a minimum measurement (e.g., a minimum value among measurements) associated with a beam in the subset of beams; an average measurement (e.g., mean, median, mode) of many or all beams in the subset of beams; a change in value from a previous measurement report; a differential value from another measurement in the report (e.g., a WTRU may report a measurement (e.g., highest measurement) associated with a first beam in the subset and may report a differential measurement (e.g., differential compared to that of the first beam) for a second beam in the subset); or measurements for one or more beams with a greatest change since a previous report (e.g., the WTRU may report measurements for N beams with the greatest change since a previous report (e.g., where N may be configurable) or the WTRU may report measurements for any beam with a change greater than a threshold (e.g., configurable threshold)).

[0203] A WTRU may be configured with multiple measurement resources or time instances prior to a measurement report associated with a subset of beams. The WTRU (e.g., in such a case) may perform more than one measurement for at least one beam. The WTRU may determine a measurement report for at least one beam or for a subset of beams as a function of measurements obtained in the multiple measurement resources or time instances. The reported measurements may include beam measurements (e.g., all measurements for all beams obtained at all measurement or time instances). The reported measurement may be determined by at least one of: a maximum measurement associated with a beam at a specific measurement or time instance; a minimum measurement associated with a beam at a specific measurement or time instance; an average measurement (e.g., mean, median, mode) associated with a beam over all measurement or time instance; or a measurement spread (e.g., highest measurement minus lowest measurement) associated with a beam over all measurements or time instances.

[0204] A WTRU may indicate (e.g., additionally indicate) the measurement or time resource from which a reported measurement is obtained. A WTRU may (e.g., may also) indicate an index (e.g., CRI) of the one or more beams for which a reported measurement is applicable.

[0205] A WTRU may determine a measurement or time instance where a beam measurement is the highest. The WTRU may report the measurement and the index of the associated beam. The WTRU may report the measurement or time instance associated with the measurement. The WTRU may report differential measurements for beams (e.g., all other beams) in the subset of beams. The differential measurements may be for the same measurement or time instance. The differential measurements may be for each beam’s maximum value over (e.g., all the) possible measurements or time instances.

[0206] The WTRU may determine a measurement (e.g., maximum, minimum, or average) over multiple or all measurements or time instances for beams (e.g., each beam) in a subset of beams. The WTRU may report the highest or lowest (e.g., maximum, minimum, or average) value along with the beam index of the beam with the (e.g., maximum, minimum, or average) value. The WTRU may report differential values for beams (e.g., all other beams) in the subset, where the differential value may be obtained as the differences between the (e.g., maximum, minimum, or average) value of the beam with the highest (e.g., maximum, minimum, or average) value and the (e.g., maximum, minimum, or average) value of the other beam.

[0207] Examples of selections of subsets to report are provided herein. The WTRU may be configured to report at least one measurement for one or more subsets of beams. The configuration may indicate the specific subsets of beams to report. The configuration may indicate the specific resources or time instances to use to report the at least one subset of beams. The configuration may indicate the one or more specific time instances or resources on which to perform a measurement associated with a subset of beams. The configuration may indicate a set of specific time instances or resources on which to report a measurement associated with a subset of beams. The configuration may include the measurement type(s) to report.

[0208] A WTRU may determine the subset of beams to report at a specific time instance or in a specific reporting resource as a function of at least one of: the beam subset ID, a beam index of a beam in the subset of beams, the feedback resource ID, the timing of the report instance (e.g., slot number, radio frame number, symbol index, etc.), the timing of measurement resources (e.g., time location of the measurement resources), the payload of the measurement, the payload granted for the measurement reporting, or the measurement type.

[0209] A WTRU may select a subset of beams for which it may report measurements in a report resource as a function of at least one of: a timing of the report resource; a timing of a last report for a subset of beams; a change in measurement since the last measurement report for the subset of beams; a number of measurements of time stances since a last measurement report; a measurement value to report; or a request for a network node (e.g., gNB).

[0210] For the timing of the report resource, subsets of beams (e.g., each subset of beams) may be configured or associated with periodic report resources.

[0211] For the timing of a last report for a subset of beams, the WTRU may select a subset of beams to report as a function of the time elapsed since a last report for that subset of beams.

[0212] For the change in measurement since the last measurement report for the subset of beams, the WTRU may report measurements for a subset of beams for which the measurement has changed the most since a last measurement report for that subset of beams.

[0213] For the number of measurement or time instances since a last measurement report, a WTRU may be triggered to report measurements for a subset of beams as a function of the number of measurement or time instances that have occurred since a last measurement report for that subset of beams.

[0214] For a measurement value to report, a WTRU may select to report a measurement for a subset of beams if the measurement goes above or below a threshold value.

[0215] For a request from the network node (e.g., the gNB), a WTRU may receive an aperiodic request from the gNB (e.g., via DCI or MAC CE) indicated by one or more subsets of beams for which to report measurements. An aperiodic request may explicitly or implicitly indicate the index of the subset of beams for which the WTRU may report measurements. An aperiodic request may indicate a condition for a WTRU to report measurements for a subset of beams. For example, a WTRU may detect a periodic request requiring the reporting of a subset of beams with a highest measurement value, or with a measurement value with the greatest change since a previous report.

[0216] Examples of a WTRU reporting beam measurements at determined representative measurement instances are provided herein. A WTRU may report beam measurements at determined representative measurement instances considering beam measurements over L(>1) measurement instances. The WTRU may configure with L (> 1) measurement instances prior to a measurement associated with one or more beam resource sets reported. The WTRU may receive the parameter L via RRC signaling or may dynamically indicate via an MAC-CE indication or DCI an indication.

[0217] The WTRU may receive a configuration for reporting measurements corresponding to beams (e.g., each beam) over L measurement instances via an RRC signaling, an MAC-CE indication, or a DCI indication. At least one of the following measurements may be configured for reporting: the maximum measurement of a beam in L measurement instances; the minimum measurement of a beam in L measurement instances; or the average (e.g., mean, median, mode) associated with a beam over all the L measurement instances.

[0218] The WTRU may measure beams in a resource set over L measurement instances. The WTRU may report the configured one or more measurements. The WTRU may (e.g., may additionally) indicate the measurement instance from which a reported measurement is obtained.

[0219] A WTRU may report beam (e.g., RS resource) measurements associated with a subset of beams (e.g., RS resources) (e.g., via sparse reporting) for selected or configured measurement instances (e.g., if the WTRU is configured or indicated to report beam (e.g., RS resource) measurements of more than one measurement instance (e.g., semi-persistent beam reporting). The WTRU may activate or deactivate sparse reporting based on a variation of beam (e.g., RS resource) measurements between consecutive measurement instances. The WTRU may determine a subset of beams (e.g., RS resources) to report beam (e.g., RS resource) measurements on in measurement instances (e.g., each measurement instance) with sparse reporting (e.g., based on a gNB configuration or beam (e.g., RS resource) measurements). Beam reporting overhead may be reduced via spatial and temporal domain compression.

[0220] The WTRU may determine and report assistance information (e.g., a change in direction of movement, rotation, antenna panel switch). This may help a network node (e.g., a gNB) to determine whether to use (e.g., updated) RS resource measurements for beam inference or mode training.

[0221] The WTRU may (e.g., after reporting the assistance information to the network node) be configured with (e.g., receive configuration information) one or more of: RS resource set(s), a number k of measurement instances (e.g., initial measurement instances), a reference time instance, a number N of RS resource measurements, a sparse reporting activation threshold, or a sparse reporting threshold. [0222] The WTRU may receive configuration information (e.g. , via an RRC) or an indication from the network node (e.g., gNB) (e.g., via a DCI) to measure and report RS resource measurements of the one or more RS resources sets over multiple measurement instances.

[0223] The WTRU may receive an indication or configuration information from the gNB to enable sparse reporting (e.g., via an RRC or an MAC-CE). Sparse reporting may be defined as a WTRU reporting measurements for a (e.g., selected or determined or indicated) subset of RS resources at a reporting instance (e.g., a sparse reporting instance).

[0224] The WTRU may determine a sparse reporting activation or deactivation based on RS resource measurements performed in an RS resource set. (e.g., over a number of measurement instances N (e.g., N = 2) measurement instances). For example, if time-domain differential measurements of more than a number of beams in an RS resource set is less than a configured sparse reporting activation threshold, sparse reporting may be activated.

[0225] If sparse reporting is activated, the WTRU may select a subset of RS resources for which to report measurements at sparse reporting instances (e.g., each sparse reporting instance) based on at least one of: gNB configuration information or an indication (e.g., a preconfigured pattern by the gNB); WTRU measurements (e.g., time-domain differential measurements (e.g., the WTRU selects RS resources with magnitude of time-domain differential measurement exceeding a sparse reporting beam selection threshold); or RS-resource differential measurements exceeding a sparse reporting beam selection threshold). The number sparse reporting instances may be the difference between the total number of measurement instances (N) and the number of initial measurement instances (k) (e.g., N - k).

[0226] The WTRU may report the set of RS resources selected in a bitmap if the selection is based on measurements (e.g., if the WTRU selects the subset of RS resources for which to report measurements). The WTRU may report the set of RS resources selection in a pattern ID if the selection is based on a pattern (e.g., the preconfigured pattern).

[0227] The WTRU may report RS resource measurements with sparse reporting (e.g., at the sparse reporting instance(s)).

[0228] In examples, for the first k measurement instances (e.g., the initial measurement instances), the WTRU may report RS resource measurements for (e.g., all the) RS resources in an RS resource set. In subsequent sparse reporting instance(s) (e.g., N - k instance(s)) (e.g., based on sparse reporting being activated), measurements of the selected subset of beams may be reported (e.g, time-domain differential measurements or RS-resource differential measurements).

[0229] Examples of beam reporting with multiple beam resource sets are provided herein.

[0230] A WTRU may receive configuration information for multiple beam resource sets (e.g., M resource sets) for monitoring beams and potentially reporting them. Configurations may correspond to spatial domain beam predictions whereby a WTRU may report beam measurements (e.g., L1 -RSRP measurements) of a large number of beams and indicate their best beam. Configurations may correspond to temporal domain beam prediction where a WTRU may report beam measurements over multiple time instances (e.g., consecutive time instances or alternative time instances or every T number of time instances (T > 1), etc.) and reporting time instances (e.g, each reporting time instance) the WTRU may (e.g, may also) report the best beam. Configurations received by the WTRU may include beam resource sets for both or one of spatial and/or temporal beam prediction. In either temporal or spatial beam prediction, the WTRU may report more than one best beam (e.g, a beam with highest L1-RSRP, a beam with second highest L1 -RSRP, etc.). The WTRU may report the probability of being the best beam out of a configured set of beams.

[0231] For the one or more best beams at reporting instances (e.g, each reporting instance), if the reported best beam index is not associated with a measurement reference signal (e.g, the best beam index derived from measurements of reference signals associated with other beams), the WTRU may report a value of confidence level. The confidence level may range from 0 to 1 to indicate the confidence level. The confidence level value toward ‘0’ may imply that the prediction accuracy is unreliable while the confidence level value toward T may imply that the prediction accuracy is reliable. If the reported best beam index is associated with a measurement reference signal, a WTRU may indicate the confidence level ‘T.

[0232] A WTRU may be configured with multiple CSI-RS resource sets for beam reporting. For example, the nzp-CSI-RS-SSB of a CSI-ResourceConfig may be configured with multiple nzp-CSI-RS- ResourceSetLists. The resource sets may be configured in a way to reduce reporting overhead and enable the WTRU to report a smaller subset of beams.

[0233] The CSI-RS-ResourceSets may be configured by the network to ensure that beams within the resource set are ordered such that adjacent beams are correlated. For example, beams (e.g, all beams) in a CSI-RS-ResourceSet associated with the same sector and azimuth angle may be indexed based on an azimuth angle.

[0234] The CSI-RS-ResourceSets may be configured by the network such that beams within the resource set have similar beam measurements (e.g., L1 -RSRP values). For example, resource sets (e.g., each resource set) may be configured with beam resources corresponding to a particular sector, panel, and/or elevation angle such that the beams are likely to have similar L1 -RSRP values. Supporting beam indexing or beam ordering based on orientation or angles in this way may reduce the CSI reporting overhead.

[0235] A WTRU may report beam measurements for a subset of beam resource sets out of (e.g., all the) beam resource sets received from the network. WTRU selection of the beam resource sets may rely on one or more of the following: a beam measurement (e.g., L1 -RSRP) based on a beam resource set determination; a differential beam measurement (e.g., differential L1 -RSRP) based beam resource set determination; a variance based beat set determination; or a PUCCH/PUSCH based beam resource set determination.

[0236] For the beam measurement (e.g., L1-RSRP) based beam resource set determination, the WTRU may report beam measurements of the resource set where the beam with the highest beam measurement (e.g., L1 -RSRP) was measured and/or the WTRU may simply report the beam with the highest beam measurement (e.g., beam index or beam ID).

[0237] For example, the WTRU may report beam measurements of resource sets (e.g., each resource set) with a maximum beam measurement (e.g., L1 -RSRP) and/or an average beam measurement (e.g., average L1 -RSRP) above a threshold preconfigured by a gNB. The WTRU may (e.g., may also) report the one or more beam with the highest or average beam measurement (e.g., highest or average L1 -RSRP) above the preconfigured threshold (e.g., beam index or beam ID).

[0238] For example, the WTRU may report the highest beam measurement (e.g., highest L1-RSRP) per sector. The sectors may have been predefined or preconfigured by the gNB in the WTRU. In examples, sector 1 may correspond to beam indices 0-15, sector 2 to beam indices 16-31 , and so forth. The sectors may (e.g., may also) be defined in terms of the azimuth angles. A change in the position of the WTRU beyond a preconfigured threshold may trigger reconfiguration of the sectors (e.g., via RRC (re)configuration). [0239] For example, the WTRU may report beam measurements of the resource set where the beam with the lowest beam measurement (e.g., lowest L1 -RSRP) was measured and/or the WTRU may simply report the beam corresponding to the lowest beam measurement (e.g., lowest L1 -RSRP) (e.g., beam index or beam ID). This may be a one-shot reporting that may assist the network to discount or deprioritize that beam if configuring beam resources for future time instances. The WTRU may be configured to do a one- shot reporting of the sector, the elevation angle, and/or panel with the beam with the lowest beam measurement to assist the network to deprioritize that particular sector, elevation angle, and/or panel in future time instances if configuring beam resources for the WTRU. The network may (e.g., may also) use this information to deprioritize adjacent beams (e.g., to the beam with the lowest L1-RSRP).

[0240] For example, the WTRU may report average beam measurements per sector, elevation angle, and/or panel to the gNB to assist the gNB in configuring beam resources for future time instances. In examples, the gNB may not configure beam resources for the sector, elevation angle, and/or panel with the lowest reported beam measurement (e.g., lowest L1 -RSRP measurements).

[0241] For the differential beam measurement (e.g., differential L1-RSRP) based beam resource set determination, the WTRU may report beam measurements for a subset of beam resource sets based on the differential beam measurement (e.g., L1 -RSRP) from the previous measurement. For example, if the differential L1 -RSRP from the previous measurement (e.g., measurement in the previous time instant) is above a preconfigured threshold, the WTRU may report the most recent beam measurements. In the case of spatial beam prediction, if the differential L1-RSRP between two adjacent beams out of the subset of beam resources that were previously reported exceeds a preconfigured threshold, the WTRU may report the most recent beam measurements. For example, the WTRU may report the absolute L1-RSRP of one beam (e.g., beam with the highest L1 -RSRP) and differential L1-RSRP of up to a maximum of N additional beams (e.g., N = 3) for the beam with the second highest L1 -RSRP, third highest L1 -RSRP measurements, and so forth.

[0242] For the variance based beam set determination, the WTRU may report beam measurements of the beam resource set including the beam with the maximum beam measurement (e.g., maximum L1 - RSRP) and the resource set with a maximum beam measurement variance (e.g., maximum L1 -RSRP variance) (e.g., if it is different from the resource set with the maximum beam measurement).

[0243] For the PUCCH/PUSCH based beam resource set determination, the WTRU may report beam measurements of a beam resource set based on the availability of PUCCH or PUSCH resources. For example, the WTRU may report L1 -RSRP of the best one beam if a limited amount of PUCCH or PUSCH resources is available, or a L1-RSRP for the best N beams (N > 1) if more PUCCH or PUSCH resources are available. For example, the WTRU may report L1-RSRP for the best beam per sector if additional PUCCH or PUSCH resources are available. For example, the WTRU may report beam measurements of the resource set with the maximum L1 -RSRP at time instances (e.g., additional time instances) (e.g., increased reporting frequency) based on the availability of PUCCH or PUSCH resources.

[0244] The WTRU may be dynamically and/or semi statically indicated or configured by the network to report beam measurements of a subset of beam resources. For example, the WTRU may be configured to report beam measurements of a subset of beam resources at specific or predefined time intervals configured by the network. The WTRU may be indicated or configured with specific periodicities for reporting, explicit timings for reporting, and/or timing intervals from previous measurements when the WTRU would have to report (e.g., updated) measurements.

[0245] For example, the WTRU may be configured to report beam measurements of a subset of beam resources every time the WTRU performs measurements.

[0246] For example, the WTRU may be configured with thresholds corresponding to the L1 -RSRP measurements such that a change in measurement with respect to the last measurement report for the subset of beams beyond a preconfigured threshold may trigger the WTRU to report beam measurements of the subset of beam resources.

[0247] For example, the WTRU may be configured to report L1 -RSRP measurements for a subset of beam resources if there is a change in the beam with the highest L1 -RSRP measurement. The WTRU (e.g., in that case) may be configured to report the beam (e.g., updated beam) with the highest L1 -RSRP measurement (e.g., beam index, beam ID) and/or the L1 -RSRP measurement.

[0248] For example, the WTRU may report beam measurements of a subset of beam resources on reception of an ad-hoc request to do so from the network.

[0249] A WTRU may be configured to report beam measurements of a subset of beam resources if AI/ML model performance goes below a threshold. The AI/ML model performance may be at least one of beam prediction accuracy, a number of consecutive NACKs, beam failure instance occurring N times, or a number of OoS (Out-of-Sync) from RLM measurement.

[0250] The WTRU may report multiple beam measurements of selected beam resource sets. For example, the WTRU may report L1-RSRP of the best beam (e.g., the beam with highest L1-RSRP measurement) and its CRI along with differential L1 -RSRP of the rest of the beams the beam resource sets selection (e.g., for each of the beam resource sets selected).

[0251] The WTRU may report beam measurements of a subset of beam resource sets and report partial beam measurements or parameters associated with beam measurements of the remaining resource sets. For example, for the remaining resource sets, the WTRU may (e.g., may only) report L1-RSRP if above a preconfigured threshold, or the WTRU may report an average or median L1 -RSRP of the beams (e.g., all the beams) in the resource set. For example, the WTRU may report beam measurements of resource set(s) associated with the sector, panel, and/or elevation angle currently serving the WTRU with higher reporting frequency. For the remaining resource sets (e.g., corresponding to remaining sectors or panels or elevation angles), the WTRU may report the CRI and L1-RSRP of the best beams with a lower reporting frequency. For example, partial L1 -RSRP measurements may include one or more of the following: a CRI of beam with highest L1 -RSRP measurement and the L1 -RSRP; a number of beam resources with L1 - RSRP above a threshold; or a median or average L1 -RSRP of the beams in the beams resource set.

[0252] If a WTRU determines to report beam measurements of a subset of beam resources sets (e.g., as one or more triggering conditions are met), a WTRU may request an uplink resource to report the beam measurements of the subset of beam resource sets.

[0253] A WTRU may be configured (e.g., receive configuration information) or indicated to report beam (e.g., RS resource) measurements of a first number of resource sets (e.g., M > 1) beam resources (e.g., RS resource) sets. The WTRU may report a configured first set of measurements for a selected second number of RS resource set(s) (e.g., S < M) beam resource (e.g., RS resource) set(s)). The WTRU may determine the S beam resource (e.g., RS resource) sets based on beam (e.g., RS resource) measurements (e.g., a beam resource (e.g., RS resource) set may be selected for reporting beam (e.g., RS resource) measurements if the beam (e.g., RS resource) measurement (e.g., L1 -RSRP) of at least one beam (e.g., RS resource) in the RS resource set > a threshold configured by the gNB). For a third number of RS resource sets (e.g., the remaining RS resource sets or unselected number of the first number of RS resource sets), the WTRU may report a second set of measurements. The WTRU may not report any beam (e.g., RS resource) measurement of beams (e.g., RS resources) associated with RS resource sets not selected.

[0254] A WTRU may be configured (e.g., receive configuration information) to report RS resource measurements. The configuration information may include a first number of RS resource sets (e.g., M RS resource sets) and an RS resource set selection criterion. [0255] The WTRU may receive configuration information or an indication for selecting a second number of RS resource set from the first number of RS resource sets (e.g., selecting S (< M) RS resource sets out of M RS resource sets) based on the RS resource set selection criterion (e.g., select the S RS resource set(s) that includes the RS resource(s) with a maximum measurement value (e.g., L1-RSRP), or select the S RS resource set(s) with an average measurement value exceeding a preconfigured threshold).

[0256] The WTRU may perform RS resource measurements (e.g., L1 -RSRP) for the first number of RS resource sets (e.g., M RS resource sets). The WTRU may determine the second number of RS resource sets (e.g., value of S, and the S selected RS resource sets) for measurement reporting based on the configured RS resource set selection criteria.

[0257] The WTRU may report a first measurement type (e.g., per-RS resource L1-RSRP) for the second number of RS resource sets (e.g., S selected RS resource sets) and may report a second measurement type (e.g., per-RS-resource-set average L1-RSRP) for the third number of RS resource sets (e.g., (M-S)) (e.g, the unselected RS resource sets).

[0258] Examples of adapting reporting parameters to increase the accuracy of reported measurements are provided herein. A WTRU may be indicated, configured, and/or determined to report beam measurements (e.g, L1 -RSRP, SINR) with a selected value (e.g, one out of a set of possible options configured by gNB) for one or more parameters, hereafter referred to as reporting parameters or a reporting parameter set. Reporting parameters include one or more of the following: a reporting range (e.g, the maximum and minimum L1-RSRP values, maximum and minimum differential L1 -RSRP values); stepsize to quantized measurements (e.g, step size to quantize L1 -RSRP, step size to quantize differential L1- RSRPs); a number of quantization levels (or the number of reporting bits) for beam measurements and/or number of quantization levels (e.g, number of reporting bits) for differential beam measurements.; or a number of bits to be used for beam measurements reporting (e.g, number of bits to report L1 -RSRP and/or differential L1 -RSRP).

[0259] To select values of one or more reporting parameters, at least one or a combination of the following examples may be applied. A WTRU may use one or more of these examples to select the values for reporting parameters corresponding to one or more beam resource sets, all beam resource sets associated with a report request (e.g, beam resource sets indicated by CSI -ResourceConfig associate with CSI-ReportConfig), or beam reports (e.g, all beam reports) associated with a report requested for a preconfigured duration (e.g, a number of CSI report, a number of slots, or x milliseconds, or until a set of values (e.g., an updated set of values) for reporting parameters are indicated, configured, and/or determined).

[0260] The WTRU may be indicated or configured with one or more possible configurations or options for one or more reporting parameters by the gNB (e.g., via a DCI, an MAC-CE and or an RRC). In the case more than one configuration is indicated or configured for one or more reporting parameters, the WTRU may determine a configuration by one or more examples.

[0261] The WTRU may be configured with more than one value for one or more reporting parameters by the gNB (e.g., via an RRC signaling). The WTRU may select one value out of the configured values (e.g., all the configured values) for each reporting parameter based on one or more of the following parameters: a frequency range and/or an SCS; a number of beam resources in a resource set; a number of beam resource sets associated with a reporting request; a waveform; beam type; UL resources the WTRU is configured to indicated to beam measurements on; a type of resources WTRU is configured to report measurements on; a report configuration type; a reporting measurement; an indication, configured, or determined value or option of one reporting parameter; a configuration associated with the beam selection mechanism for reporting; one or more configurations associated with the measurement reporting configured or indicated by the gNB; a CORESET pool index; or a WTRU selected value or option for one or more reporting parameters based on the beam resource set ID.

[0262] For the frequency range and/or SCS (e.g., with FR2-1), the WTRU may select the first value for reporting parameters (e.g., each reporting parameter). The WTRU (e.g., with FR2-1) may select the second value for reporting parameters (e.g., each reporting parameter).

[0263] For the number of beam resources in a resource set, if the number of resources exceeds a preconfigured threshold, the WTRU may use the first step-size for L1-RSRP reporting. If the number of resources does not exceed the threshold, the WTRU may use the second step-size for L1-RSRP reporting. [0264] For the number of beam resource sets associated with a reporting request, if the number of beam resource sets associated with a CSI-ReportConfig exceeds a preconfigured value, the WTRU may select the first step-size for L1-RSRP reporting. If the number of resource sets do not exceed the threshold, WTRU may select the second step-size for L1-RSRP reporting.

[0265] For the waveform, the WTRU may select a first value for a reporting parameter for CP-OFDM and a second value for DFT-s-OFDM.

[0266] For the beam type, the beam may be a CSI-RS or an SSB. [0267] For UL resources the WTRU is configured or indicated to report beam measurements on, the WTRU may be configured to report beam measurements on a PUCCH. The WTRU may use a first stepsize option for L1-RSRP reporting. If the WTRU is configured to report beam measurements on a PUSCH, the WTRU may use the second step-size option for L1 -RSRP reporting.

[0268] For the type of resources the WTRU is configured to report beam measurements on, the WTRU may use the first step-size for L1-RSRP reporting if a PUCCH resources beam report configured or indicated to be sent is of short PUCCH type. The WTRU may use the second step-size for L1-RSRP reporting if the PUCCH resources of long PUCCH type.

[0269] For the report configuration type, the configuration type may be ‘reportConfigType’ in CSI- ReportConfig, semiPersistent, aperiodic, or periodic.

[0270] For the reporting measurement, the reporting measurement may include L1-RSRPs of beams in a resource set or an average L1-RSRP of all the beams in a resource set.

[0271] For the indicated, configured, or determined value or option of one reporting parameter, the WTRU may receive the association between quantization step-sizes and the range options from the gNB (e.g., via an RRC signaling). The WTRU may receive a quantization step-size from the gNB via dynamic signaling (e.g., a DCI or an MAC-CE signaling). The WTRU may select a range option based on indicated quantization step-size.

[0272] For the configuration associated with the beam selection mechanism for reporting, with sparse reporting or without sparse reporting, the WTRU may be configured with two step-size values and/or range options. The WTRU may use the first step-size option and/or the first range option with sparse reporting. The WTRU may use the second step-size option and/or the second range option if beam reporting is done without sparse reporting. For the configuration associated with the beam selection mechanism for reporting, the WTRU may perform beam selection with or without representation beam selection across different measurement instances. For the configuration associated with the beam selection mechanism for report, the WTRU may perform beam selection with or without representative beam selection if reporting beam measurements belongs to the same measurement instance (e.g., if a representation beam selection is enabled, the WTRU may select the first step-size for L1-RSRP reporting and if a representative beam selection is disabled, the WTRU may select the second step size for L1-RSRP reporting).

[0273] For one or more configurations associated with the measurement reporting examples configured or indicated by the gNB, the configurations may include one or more of the following: reference beam selection examples (e.g., the WTRU may select the first quantization step-size for differential L1-RSRP reporting if the beam with the highest L1-RSRP is configured, indicated, or determined to be used as the reference beam or the WTRU may select the second step-size if the L1-RSRP of the adjacent beam is indicated, determined or, configured to be selected as the reference); a type of reference beam (e.g., a beam with highest L1-RSRP as the reference beam or the beam with the median L1 -RSRP as the reference beam for L1-RSRP reporting); or a reference beam selection option for a time-domain differential beam measurement in sparse reporting.

[0274] For the CORESET pool index (e.g., for CORESET pool index = ‘O’, the WTRU may select the first value for a reporting parameter; for CORESET pool index = ‘1’, the WTRU may select the second value for a reporting parameter).

[0275] For the WTRU selecting a value or option for one or more reporting parameters based on the beam resource set ID, the WTRU may receive a configuration from the gNB associating each beam resource set ID with a step-size and/or a range option via an RRC/MAC-CE. The WTRU may determine a step-size option and/or a range option for each beam resource set associated with a measurement report (e.g., CSI-ReportConfig) based on the configured association.

[0276] A WTRU may determine one or more reporting parameters based on beam quality measurements. The WTRU may indicate or report the determined reporting parameters to the gNB (e.g., via a PUCCH or an MAC-CE). For example, a WTRU may be configured with multiple range options for differential L1 -RSRP measurement reporting (e.g., range-option 1 , range-option 2 where range option 2 has a higher range than range option 1 , and range option 3 which has higher range than both range option 1 & 2). The WTRU may determine range-option 1 for reporting differential L1 -RSRP for a beam resource set (e.g., if all the differential L1 -RSRPs are withing range-option 1). The WTRU may select range-option 2 for reporting differential L1-RSRP measurements of the beam resource set (e.g., if all the differential L1- RSRPs are withing range-option 2 but at least one differential L1 -RSRP measurement is outside of rangeoption 1 ).

[0277] The WTRU may use a set of reporting parameters preconfigured (e.g., via an RRC signaling) until an implicit or explicit indication is received by the gNB. Each time the implicit indication (e.g., the UL transmit power increases or decreases command by the gNB) or the explicit indication (e.g., 1 bit indication by the gNB via an MAC-CE or a DCI) is received by the WTRU, the WTRU may determine a different set of parameters based on a preconfigured rule. For example, a WTRU may determine the range for L1-RSRP reporting by the default configuration (e.g., the range corresponding to the lowest index in a configured table). Each time the WTRU receives an indication to decrease the transmit power from the gNB, the WTRU may decrease the range by a preconfigured value by the gNB (e.g. , via an RRC signaling).

[0278] The WTRU may determine values of one or more reporting parameters based on a trigger condition (e.g., toggling the CORESET pool index, a change in the TCI state for PDCCH or PDSCH reception, or a preconfigured number of measurement or reporting instances). Until the trigger condition is met, the WTRU may use a preconfigured one or more reporting parameters (e.g., via a default configuration). For example, a WTRU may select a preconfigured first set of values for reporting parameters (e.g., a lowest step-size for reporting L1 -RSRP) for the first k (e.g., k = 1) number of measurement instances configured by the gNB. The WTRU may select to report beam measurements (e.g., after k number of beam measurement instances) with a second set of reporting parameter values (e.g, highest step-size for reporting L1-RSRP). For example, a WTRU may use a configured set of values for reporting parameters until a change of one or more conditions are determined. These conditions may include at least one of: the WTRU’s speed increases or decreases beyond a threshold; a change in the WTRU’s direction of movement; the WTRU changes in the antenna panels; a level of interference increased or decreased beyond a preconfigured threshold; a remaining transit power that drops below a preconfigured threshold; a change in the CORESET pool index; a change in the TCI state associates with PDCCH or PDSCH; or a change of LoS condition. If one or more conditions are met, the WTRU may determine values (e.g, updated values) for one or more reporting parameters and indicate the values to the gNB (e.g, via a PUCCH or an MAC-CE). The WTRU may monitor for a confirmation from the gNB within a monitoring window (e.g, via a DCI or MAC-CE within N slots after request for changing reporting parameters is sent). If the WTRU does not receive a confirmation within the monitoring window, the WTRU may continue with the same reporting parameters. If the WTRU receives a confirmation from the gNB, the WTRU may switch to the determined set (e.g, updated set) of reporting parameters.

[0279] A WTRU may use a preconfigured set of values for one or more reporting parameters until a counter or timer expires. If the counter or timer expires, the WTRU may select second set of preconfigured values for one or more reporting parameters by the gNB. For example, the WTRU may report beam measurements with a highest step-size for L1 -RSRP reporting until a counter (e.g, counter that counts the number of beam measurement instances or counter that counts the number of times a MSE error estimation exceeds a preconfigured threshold) or a timer expires (e.g, number of slots from the first measurement instance). If the counter or timer expires, the WTRU may select the lowest step-size for L 1 - RSRP reporting. [0280] A WTRU may determine a set of values for reporting parameters based on required accuracy or granularity out of a set of preconfigured possible different accuracy or granularity levels (e.g., high, medium, low).

[0281] A WTRU may determine that the MSE associated with one or more reporting parameters (e.g., step-size for differential L1 -RSRP reporting) exceeds preconfigured thresholds by the gNB. The WTRU may request to switch the accuracy or granularity level to a different level out of a configured set of levels (e.g., low, medium, high). The WTRU may monitor for a confirmation from the gNB (e.g., via a DCI or MAC- CE). If a confirmation is received, the WTRU may switch reporting parameters to the determined accuracy or granularity level. The WTRU may not (e.g., otherwise) change the reporting parameters.

[0282] A WTRU may report with a configured, determined, or indicated set of reporting parameters corresponding to enhanced accuracy or granularity until one or more stop conditions are met. If the stop condition is met, the WTRU may report beam measurements with the reporting parameters used before enhanced reporting parameters are used. The stop conditions for enhanced reporting may include one or more of the following: one shot reporting with enhanced reporting parameters successfully received by the gNB (e.g., confirmed via a UL ACK procedure); expiration of a counter; or expiration of a timer.

[0283] For the expiration of a counter, a counter may count the number of measurement instances or reporting instances with enhanced values for reporting parameters. If the counter exceeds a preconfigured threshold by the gNB (e.g., via RRC signaling), the WTRU may fall back to using the reporting parameters used before the enhanced reporting parameters are used.

[0284] For the expiration of a timer, a timer may start if a determined, indicated, or configured set of enhanced values for reporting parameters are stated to use (e.g., in terms of number of slots, milliseconds). If the timer expires, the WTRU may fall back to using the reporting parameters used before the enhanced reporting parameters are used.

[0285] A WTRU may be indicated, configured, or determined to fall back to a second set of values for reporting parameters (e.g., after the expiration of a counter or a timer). Before the fall back takes place, the WTRU may use a first set of values for reporting parameters. The WTRU may choose at least one of the following procedures to determine second set of values for reporting parameters: the WTRU may select first set of values for reporting parameters after falling back takes place; the WTRU may select the values of reporting parameters corresponding to the lowest accuracy (e.g., highest step-size for L1-RSRP reporting); or the WTRU may increase or decrease the value of reporting parameters or values of multiple reporting parameters by k number of granularity levels (e.g., k =1) preconfigured by the gNB (e.g., via RRC signaling).

[0286] A WTRU may be indicated, configured, or determined to report compressed information of the beam measurements of one or more beams over one or more time instances. For example, a WTRU may perform beam measurements (e.g., L1-RSRP) of X beams over Y time instances and the WTRU may report compressed information. The compressed information may include one or more of the following: beam measurement distribution in statistical distribution form (e.g., uniform distribution, normal distribution, log-normal distribution, etc.) and its associated parameters (e.g., mean, standards deviation, etc.); one or more best beam indexes and its associated L1 -RSRP values; a range of beam measurement values; or a preferred AI/ML model (e.g., prediction model). The preferred AI/ML model may be reported or indicated based on AI/ML model identity.

[0287] A WTRU may select reporting parameters (e.g., maximum and minimum beam (e.g., RS resource) measurement values reported, quantization step-size for one or more measurements, a number of quantization levels or number of bits used for beam (e.g., RS resource) measurement reporting) to increase the accuracy of beam measurements reported.

[0288] The WTRU may select a configuration or value associated with one or more reporting parameters (e.g., maximum and minimum L1-RSRP, quantization step size for L1 -RSRP or differential L1-RSRP, number of quantization steps) adaptively.

[0289] A WTRU may be configured with (e.g., may receive) multiple measurement reporting configurations. The measurement reporting configurations may include at least one of the following parameters: a range of measurements (e.g., L1 -RSRP) values, a maximum/minimum value, a quantization step-size, a number of quantization levels, or a number of bits used reporting (e.g., for the report).

[0290] The WTRU may be configured with (e.g., receive configuration information of) an RS resource set on which to perform measurements. The WTRU may perform measurements on the RS resources of the configured RS resource set.

[0291] The WTRU may select (e.g., adapt) the measurement reporting configuration or a parameter of a measurement reporting configuration based on at least one of: RS resource measurement values; an RS resource set configuration (e.g., FR, SCS, waveform, RS resource type); feedback resource parameters (e.g., feedback resource type, payload, resource); a reception of an indication (e.g., a DCI or an MAC CE indication, a UL transmit power change, toggling of a CORESET pool index); timing of a measurement or measurement report; or requirements of a feedback report or an associated transmission (e.g., feedback accuracy requirements).

[0292] The WTRU may apply a selected measurement reporting configuration (e.g., or a selected parameter of a measurement reporting configuration) to RS resource set measurements to obtain RS resource set measurement report values.

[0293] The WTRU may report the selected measurement reporting configuration (e.g., or selected parameter of a measurement reporting configuration) and may report the RS resource set measurement report values.

[0294] Although features and elements described above are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments, or in various combinations with or without other features and elements.

[0295] Although the implementations described herein may consider 3GPP specific protocols, it is understood that the implementations described herein are not restricted to this scenario and may be applicable to other wireless systems. For example, although the solutions described herein consider LTE, LTE-A, New Radio (NR) or 5G specific protocols, it is understood that the solutions described herein are not restricted to this scenario and are applicable to other wireless systems as well.

[0296] The processes described above may be implemented in a computer program, software, and/or firmware incorporated in a computer-readable medium for execution by a computer and/or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted over wired and/or wireless connections) and/or computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as, but not limited to, internal hard disks and removable disks, magneto-optical media, and/or optical media such as compact disc (CD)-ROM disks, and/or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, terminal, base station, RNC, and/or any host computer.

Claims

CLAIMS What is Claimed:

1 . A wireless transmit/receive unit (WTRU), the WTRU comprising: a processor configured to: determine assistance information and report the assistance information to a network node; after reporting the assistance information to the network node, receive configuration information, wherein the configuration information indicates a set of reference signal (RS) resources; perform measurements of the set of RS resources; determine that sparse reporting is activated based on time-domain measurements of a number of beams in the set of RS resources being less than a sparse reporting activation threshold; based on the sparse reporting being activated, select a subset of RS resources for measurement reporting from the set of RS resources; and report the selected subset of RS resources and measurements associated with the subset of RS resources.

2. The WTRU of claim 1 , wherein the processor is further configured to: report the measurements of the set of RS resources at a number of reporting instances; and based on the sparse reporting being activated, report the measurements of the subset of RS resources at a sparse reporting instance, wherein the sparse reporting instance occurs after the number of reporting instances.

3. The WTRU of claim 1 , wherein the processor is further configured to: based on the sparse reporting being activated, select the subset of RS resources for measurement reporting from a set of subsets of RS resources.

4. The WTRU of claim 1 , wherein the sparse reporting activation threshold is preconfigured by the network node.

5. The WTRU of claim 1 , wherein: the selection of the subset of RS resources is based on a magnitude of time-domain differential measurements exceeding a sparse reporting beam selection threshold; and the subset of RS resources is reported within a bitmap.

6. The WTRU of claim 1 , wherein: the selection of the subset of RS resources is based on a magnitude of RS resource differential measurements exceeding a sparse reporting beam selection threshold; and the subset of RS resources is reported within a bitmap.

7. The WTRU of claim 1 , wherein: the selection of the subset of RS resources is based on a preconfigured pattern; and the subset of RS resources is reported via a pattern ID.

8. The WTRU of claim 1 , wherein the assistance information is at least one of: a change in direction of movement, a rotation, or an antenna panel switch.

9. A method associated with wireless transmit/receive unit (WTRU), the method comprising: determining assistance information and report the assistance information to a network node; after reporting the assistance information to the network node, receiving configuration information, wherein the configuration information indicates a set of reference signal (RS) resources; performing measurements of the set of RS resources; determining that sparse reporting is activated based on time-domain measurements of a number of beams in the set of RS resources being less than a sparse reporting activation threshold; based on the sparse reporting being activated, selecting a subset of RS resources for measurement reporting from the set of RS resources; and reporting the selected subset of RS resources and measurements associated with the subset of RS resources.

10. The method of claim 9, further comprising: reporting the measurements of the set of RS resources at a number of reporting instances; and based on the sparse reporting being activated, reporting the measurements of the subset of RS resources at a sparse reporting instance, wherein the sparse reporting instance occurs after the number of reporting instances.

11 . The method of claim 9, further comprising: based on the sparse reporting being activated, selecting the subset of RS resources for measurement reporting from a set of subsets of RS resources.

12. The method of claim 9, wherein the sparse reporting activation threshold is preconfigured by the network node.

13. The method of claim 9, wherein: the selection of the subset of RS resources is based on a magnitude of time-domain differential measurements exceeding a sparse reporting beam selection threshold; and the subset of RS resources is reported within a bitmap.

14. The method of claim 9, wherein: the selection of the subset of RS resources is based on a magnitude of RS resource differential measurements exceeding a sparse reporting beam selection threshold; and the subset of RS resources is reported within a bitmap.

15. The method of claim 9, wherein: the selection of the subset of RS resources is based on a preconfigured pattern; and the subset of RS resources is reported via a pattern ID.