WO2024173452A1 - One-shot transmission of harq codebook - Google Patents

Abstract

Disclosed herein are systems, methods, and instrumentalities associated with hybrid automatic repeat request (HARQ) feedback overhead reduction. A wireless transmit/receive unit (WTRU) may receive an indication from a network device that the WTRU is to delay HARQ transmissions. The WTRU may receive first and second downlink transmissions, and store respective HARQ feedback for the downlink transmissions based on the indication to delay the HARQ transmissions. The WTRU may then determine that a condition for transmitting the HARQ feedback for the first and second downnlink transmission is met, and may transmit the HARQ feedback via a HARQ codebook based on the determination.

Description

ONE-SHOT TRANSMISSION OF HARQ CODEBOOK

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/445,573, filed February 14, 2023, the contents of which is incorporated by reference herein.

BACKGROUND

[0002] Artificial Intelligence (AI)ZMachine Learning (ML) models may be trained for improving the performance of a wireless communication system. A wireless transmit/receive unit (WTRU) may use these pre-trained AI/ML models for aspects of beam management such as beam prediction, beam selection, etc. The WTRU may also perform conventional measurements on channel conditions, beam and/or environment changes, link-adaptation parameters, etc. Therefore, it may be desirable to utilize the predictions and/or measurements made by the WTRU to further improve the performance of the wireless communication system, for example, with respect to hybrid automatic repeat request (HARQ) feedback.

SUMMARY

[0003] Disclosed herein are systems, methods, and instrumentalities associated with hybrid automatic repeat request (HARQ) feedback overhead reduction. A wireless transmit/receive unit (WTRU) may receive an indication from a network device that the WTRU is to delay hybrid automatic repeat request (HARQ) transmissions. The WTRU may receive a first downlink transmission and store a first HARQ feedback for the first downlink transmission based on the indication to delay the HARQ transmissions. The WTRU may further receive a second downlink transmission and store a second HARQ feedback for the second downlink transmission based on the indication to delay the HARQ transmissions. The WTRU may then determine that a condition for transmitting the first HARQ feedback and the second HARQ feedback is met, and transmit the first HARQ feedback and the second HARQ feedback via a HARQ codebook based on the determination that the condition for transmitting the first HARQ feedback and the second HARQ feedback is met.

[0004] In examples, the WTRU may receive the indication to delay the HARQ transmissions via downlink control information (DCI) from the network device. In examples, the DCI may include an explicit indication that the WTRU is to delay the HARQ transmissions. In examples, the DCI may include a resource indicator or a HARQ time gap indicator that may implicitly indicate that the WTRU is to delay the HARQ transmissions. [0005] In examples, the WTRU being configured to determine that the condition for transmitting the first HARQ feedback and the second HARQ feedback is met may comprise the WTRU being configured to receive downlink control information (DCI) from the network device and determine, based on a HARQ parameter included in the DCI, that the condition for transmitting the first HARQ feedback and the second HARQ feedback is met. Such HARQ parameter may indicate a time gap associated with HARQ feedback, and the DCI may indicate one or more uplink transmission resources that the WTRU may use to transmit the first HARQ feedback and the second HARQ feedback.

[0006] In examples, the WTRU may be further configured to determine that HARQ feedback delay is to be deactivated and transmit a request to the network device to deactivate the HARQ feedback delay. The request may be included in a channel state information (CSI) report or a scheduling request transmitted to the network device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1A 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. 1A according to an embodiment.

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

DETAILED DESCRIPTION

[0011] 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.

[0012] 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 Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 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 (WTRU), 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 WTRU.

[0013] 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 (eNB), a Home Node B, a Home eNode B, a gNode B (base station), 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.

[0014] The base station 114a may be part of the RAN 104/113, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and/or the base station 114b may be configured to transmit and/or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and/or receive signals in desired spatial directions.

[0015] 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).

[0016] 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).

[0017] 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).

[0018] 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).

[0019] 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., an eNB and a gNB).

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] FIG. 1 B 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.

[0026] 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.

[0027] 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. [0028] 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.

[0029] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11 , for example.

[0030] 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).

[0031] 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.

[0032] 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. [0033] 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.

[0034] 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 UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0035] 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.

[0036] 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.

[0037] 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. [0038] 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 is 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] Although the WTRU is described in FIGS. 1 A-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.

[0044] In representative embodiments, the other network 112 may be a WLAN.

[0045] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired/wireless network that carries traffic in to and/or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and/or referred to as peer-to- peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11 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.

[0046] When using the 802.11 ac 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.

[0047] 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.

[0048] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC). [0049] 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

802.11 ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non- TVWS spectrum. According to a representative embodiment, 802.11 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).

[0050] WLAN systems, which may support multiple channels, and channel bandwidths, such as

802.11 n, 802.11 ac, 802.11 af, 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.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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).

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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. [0061] 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.

[0062] 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.

[0063] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and/or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and/or deployed as part of a wired and/or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented/deployed as part of a wired and/or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and/or may perform testing using over-the-air wireless communications.

[0064] 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.

[0065] Artificial intelligence (Al)/machine-learning (ML) may be used to improve an air interface such as beam management related functionalities associated with the air interface. The AI/ML technology may lay a foundation for improving the performance and/or reducing the complexity of multiple aspects of beam management, including beam prediction (e.g., in time and/or spatial domains for overhead and latency reduction), beam selection (e.g., to improve the accuracy of beam selection), and so forth.

[0066] Hybrid automatic repeat request (HARQ) feedback may include the transmission of an acknowledgment (ACK) or a non-acknowledgment (NACK) as a result of a WTRU verifying a correct or faulty reception of DL data, respectively. While the transmission of an NACK may trigger a retransmission of the data that was received with faulty content, the transmission of an ACK may impose overhead and/or latency to the overall communication system. This impact may be severe with a scheduler targeting a 10% block error rate (BLER) in eMBB systems or a much lower BLER (e.g., 10⁵) in URLLC systems. The lower BLER may result in a higher rate of ACK (e.g., 90% in eMBB and 1 -10⁵ in URLLC) that may become a bottleneck for overhead and latency reduction.

[0067] AI/ML models and/or channel measurements (e.g., performed based on long-term observations) may predict channel conditions, beam and/or environment changes, link-adaptation parameters, and so forth for a WTRU on a serving cell and/or with a selected beam. For example, the AI/ML models may predict if there is going to be a change in the conditions at or surrounding the WTRU that may result in more NACKs (e.g., faulty receptions due to degraded channel conditions) or more ACKs (e.g., less faulty receptions due to stable/fixed channel conditions).

[0068] The use of AI/ML models and/or measurements performed by a WTRU may lead to different WTRU behaviors, e.g., with respect to the calculation and/or transmission of ACK/NACK information bits and/or the generation of codebooks. The WTRU may determine the conditions, measurements, and/or reporting occasions for lowering ACK/NACK transmission overhead based on AI/ML models (e.g., including the training, validation, activation, and/or deactivation of the AI/ML models) and/or measurements (e.g., such as channel state information (CSI) measurements). HARQ-ACK/NACK codebook generation and/or beam management (e.g., based on predictions made by AI/ML models or measurements performed by a WTRU) may be implemented.

[0069] When referred to herein, artificial intelligence (Al) may include behaviors learned and/or exhibited by machines (e.g., computing devices). Such behaviors may include, e.g., cognitive functions associated with sensing, reasoning, adapting and/or acting. When referred to herein, machine learning (ML) may include determining ways (e.g., algorithms) for solving a problem based on learning through experience (e.g., data). Machine learning may be considered a subset of Al. Different machine learning paradigms may be employed based on the nature of the data involved or feedback available to the learning. For example, a supervised learning approach may involve learning a function that maps an input to an output based on a labeled training dataset, wherein the training dataset may include paired data comprising an input and a corresponding output. An unsupervised learning approach may involve detecting patterns in the training data with no pre-existing labels. As an example of unsupervised learning, reinforcement learning may involve performing a sequence of actions in an environment to maximize a cumulative reward. In some examples, it may be possible to perform machine learning based on a combination of the above-mentioned approaches (e.g., based on supervised and unsupervised learning). For example, a semi-supervised learning approach may use a combination of labeled data and unlabeled data during the learning (e.g., during the training of an ML model). Such a semi-supervised learning approach may fall between unsupervised learning (e.g., without labeled training data) and supervised learning (e.g., with labeled training data).

[0070] When referred to herein, deep learning (DL) may include a class of machine learning techniques that may employ an artificial neural network (ANN) including a deep neural network (DNN). Such a DNN may receive an input that may be transformed (e.g., linearly transformed) and the DNN may pass the input through an activation function (e.g., a non-linear activation function) one or multiple times. The DNN may include multiple layers, wherein a (e.g., each) layer may include a transformation function (e.g., linear transformation function) and/or an activation function (e.g., a non-linear activation function). The DNN may be trained based on training data and/or back-propagation.

[0071] When referred to herein, AI/ML (or AIML) may include one or more of the learning or neural network training techniques described above.

[0072] A WTRU may transmit or receive a channel (e.g., a physical channel) or a reference signal according to at least one spatial domain filter. The term “beam” may be used interchangeably with the term “spatial domain filter.” 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”, and the received RS or SS block may be referred to as a “reference” or “source.” As such, the WTRU may be said to transmit the target physical channel or signal according to a spatial relation with a reference or source such an RS or SS block.

[0073] The WTRU may perform a first transmission (e.g., a first physical channel or reference signal transmission) according to the same spatial domain filter as the spatial domain filter used for performing a second transmission. The first and second transmissions may be referred to as a “target” and a “reference” (or “source”) transmission, respectively. As such, the WTRU may be said to transmit the first (target) transmission according to a spatial relation with a reference to the second (reference) transmission.

[0074] A spatial relation may be configured (e.g., implicitly configured) via RRC signaling or via a MAC CE or DCI. For example, a WTRU may implicitly transmit a PUSCH and/or a DM-RS associated with the PUSCH according to the same spatial domain filter as a sounding reference signal (SRS) indicated by an SRS resource indicator (SRI) (e.g., received in DCI or configured via RRC signaling). As another example, a spatial relation may be configured via RRC signaling for an SRI or signaled by a MAC CE for a PUCCH. Such a spatial relation may be referred to as a beam indication.

[0075] The WTRU may receive a first (target) downlink channel or reference signal transmission according to the same spatial domain filter or spatial reception parameter(s) as a second (reference) downlink channel or reference signal transmission. An association may exist between a physical channel such as a PDCCH or PDSCH, and a DM-RS associated with the physical channel. In examples (e.g., when the first and second transmissions are both reference signals), such an association may exist when the WTRU is configured with a quasi-colocation (QCL) assumption type D between corresponding antenna ports. Such an association may be configured as a transmission configuration indicator (TCI) state. The WTRU may be indicated an association between a CSI-RS (or an SS block) and a DM-RS by an index to a set of TCI states configured via RRC signaling and/or signaled via a MAC CE. Such an indication may be referred to as a beam indication.

[0076] The term "TRP” (transmission and reception point) may be interchangeably used herein with the term “TP” (transmission point), “RP” (reception point), “RRH” (radio remote head), “DA” (distributed antenna), “BS” (base station), “sector,” and/or “cell” (e.g., a geographical cell area served by a BS). The term “multi-TRP” may be interchangeably used herein with the term “MTRP,” “M-TRP,” and/or “multiple TRPs.”

[0077] A WTRU may report channel state information (CSI), which may include one or more of a CSI-RS resource indicator (CRI), a SSB resource indicator (SSBRI), an indication of a panel used for reception at the WTRU (such as a panel identity or group identity), measurements such as L1-RSRP and/or L1-SINR taken from an SSB or CSI-RS (e.g., cri-RSRP, cri-SINR, ssb-lndex-RSRP, ssb-lndex-SINR, etc.), a rank indicator (Rl), a channel quality indicator (CQI), a precoding matrix indicator (PMI), a Layer Index (LI), and/or the like.

[0078] A WTRU may receive a synchronization signal/physical broadcast channel (SS/PBCH) block. The SS/PBCH block (SSB) may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and/or a physical broadcast channel (PBCH) signal. The WTRU may monitor, receive, and/or attempt to decode an SSB during initial access, initial synchronization, radio link monitoring (RLM), cell search, cell switching, and so forth.

[0079] A WTRU may measure and report channel state information (CSI). A WTRU may receive CSI related configuration information (e.g., for a connection mode), which may include CSI report configuration information, CSI-RS resource set information, and/or NZP CSI-RS resource information. The CSI report configuration information may include one or more of a CSI report quantity (e.g., a Channel Quality Indicator (CQI), a Rank Indicator (Rl), a Precoding Matrix Indicator (PMI), a CSI-RS Resource Indicator (CRI), a Layer Indicator (LI), etc.), a CSI report type (e.g., aperiodic, semi-persistent, or periodic), a CSI report codebook configuration (e.g., Type I, Type II, Type II port selection, etc.), or a CSI report frequency. A CSI-RS resource set may include one or more CSI resource settings such as NZP-CSI-RS resources for channel measurement, NZP-CSI-RS resources for interference measurement, CSI-IM resources for interference measurement, etc. NZP CSI-RS resources may include one or more of an NZP CSI-RS resource ID, a periodicity, an offset, QCL information, a TCI-state, or a resource mapping (e.g., number of ports, density, CDM type, etc.).

[0080] A WTRU may indicate, determine, or be configured with one or more reference signals. The WTRU may monitor, receive, and measure one or more parameters based on respective reference signals. For example, one or more of the following may apply and the parameters listed herein may be non-limiting examples of the parameters that may be included in reference signal measurements. Further, one or more (e.g., not all) of the parameters listed herein may be included in reference signal measurements, while other parameters may also be included in reference signal measurements.

[0081] An SS reference signal received power (SS-RSRP) may be measured based on one or more synchronization signals (e.g., demodulation reference signal (DM-RS) transmitted in a PBCH or SSS). Such a power may be determined as a linear average of the power contributions of multiple resource elements (REs) that may carry respective synchronization signals. In measuring the RSRP, power scaling for the reference signals may be applied. If an SS-RSRP is used for L1-RSRP, the measurement may be accomplished based on CSI reference signals in addition to the synchronization signals.

[0082] A CSI-RSRP may be determined based on a linear average of the power contributions of multiple resource elements (RE) that may carry respective CSI-RSs. The CSI-RSRP determination or measurement may be configured within measurement resources for one or more configured CSI-RS occasions.

[0083] An SS signal-to-noise ratio (SS-SINR) and/or an interference ratio (SS-SINR) may be measured based on one or more synchronization signals (e.g., a DM-RS in PBCH or SSS). One or both of these ratios may be determined as a linear average of the power contributions of multiple resource elements (REs) that may carry respective synchronization signals, divided by a linear average of the noise and interference power contributions by those REs. If an SS-SINR is used for L1 -SI NR, the noise and interference power measurement may be accomplished based on resources configured by higher layers. [0084] A CSI-SINR may be measured based on a linear average of the power contributions of multiple resource elements (REs) that may carry respective CSI-RSs, divided by a linear average of the noise and interference power contributions of those REs. If a CSI-SINR is used for L1 -SI NR, the noise and interference power measurement may be accomplished based on resources configured by higher layers. Otherwise, the noise and interference power may be measured based on resources that may carry the respective CSI-RSs.

[0085] A received signal strength indicator (RSSI) may be measured based on an average of the total power contributions in configured OFDM symbols and/or bandwidth. The power contribution may be received from different resources (e.g., co-channel serving and non-serving cells, adjacent channel interference, thermal noise, and so forth).

[0086] A cross-layer interference received signal strength indicator (CLI-RSSI) may be measured based on an average of the total power contributions in configured OFDM symbols (e.g., of a configured time) and/or frequency resources. The power contribution may be received from different resources (e.g., crosslayer interference, co-channel serving and non-serving cells, adjacent channel interference, thermal noise, and so forth).

[0087] A sounding reference signal RSRP (SRS-RSRP) may be measured based on a linear average of the power contributions of resource elements (REs) that may carry respective SRSes.

[0088] A CSI report configuration (e.g., a CSI-ReportConfig information element) may be associated with a bandwidth part (BWP) (e.g., indicated by a BWP-ld). One or more of the following parameters may be configured: CSI-RS resources and/or CSI-RS resource sets for channel and interference measurement, a CSI-RS report type (e.g., periodic, semi-persistent, and aperiodic), a CSI-RS transmission periodicity for periodic and semi-persistent CSI reports, a CSI-RS transmission slot offset for periodic, semi-persistent and aperiodic CSI reports, a CSI-RS transmission slot offset list for semi-persistent and aperiodic CSI reports, time restrictions for channel and interference measurements, report frequency band configuration information (e.g., wideband/subband CQI, PMI, and so forth), thresholds and modes of calculations for one or more reporting quantities (e.g., CQI, RSRP, SINR, LI, Rl, etc.), codebook configuration information, group based beam reporting configuration information, a CQI table, a subband size, a non-PMI port indication, a port index; etc.

[0089] A CSI-RS resource set (e.g., configured via an NZP-CSI-RS-ResourceSet information element) may include one or more CSI-RS resources (e.g., configured via NZP-CSI-RS-Resource and/or CSI- ResourceConfig). A WTRU may be configured with one or more of the following regarding CSI-RS resources: a CSI-RS periodicity and slot offset for periodic and semi-persistent CSI-RS resources, a CSI- RS resource mapping that may define the number of CSI-RS ports, density, CDM-types, OFDM symbols, and/or subcarrier occupancy, the bandwidth part to which a configured CSI-RS is allocated, a reference to a TCI-State including QCL source RS(s) and/or the corresponding QCL type(s). [0090] One or more of following may be associated with an RS resource set: an RS resource set ID, one or more RS resources for the RS resource set, a repetition indication (e.g., on or off), an aperiodic triggering offset (e.g., one of 0-6 slots), TRS information (e.g., true or false), etc.

[0091] One or more of following may be associated with an RS resource: an RS resource ID, a resource mapping (e.g., REs in a PRB), a power control offset (e.g., a value of -8, . . ., 15), a power control offset with SS (e.g., -3 dB, 0 dB, 3 dB, 6 dB, etc.), a scrambling ID, a periodicity and offset, QCL information (e.g., based on a TCI state), etc.

[0092] A grant or assignment (e.g., transmitted via DCI) may indicate one or more of the following: a frequency allocation, an aspect of time allocation (e.g., such as a duration), a priority, a modulation and coding scheme, a transport block size, a number of spatial layers, a number of transport blocks, a TCI state, a CRI, an SRI, a number of repetitions, whether a repetition scheme is Type A or Type B, whether the grant is a configured grant type 1 , type 2 or a dynamic grant, whether the assignment is a dynamic assignment or a semi-persistent scheduling (configured) assignment, a configured grant index or a semi- persistent assignment index, a periodicity of a configured grant or assignment, a channel access priority class (CAPC), other parameter(s) provided via DCI, by a MAC CE or by RRC signaling for the scheduling grant or assignment, etc.

[0093] A DCI indication may indicate one or more of the following: an explicit indication provided via a DCI field or via an RNTI used to mask the CRC of a PDCCH transmission, or an implicit indication that may be implied by a property such as a DCI format, a DCI size, a coreset or search space, an aggregation level, a first resource element of the received DCI (e.g., an index of a first control channel element), where a mapping between the property and its value may be provided via RRC signaling or a MAC CE.

[0094] When referred to herein, an RS may include one or more of an RS resource, an RS resource set, an RS port, an RS port group, an SSB, a CSI-RS, an SRS, a DM-RS, a TRS, a position reference signal (PRS), or a phase tracking reference signal (PTRS). When referred to herein, a reference signal may include a sounding reference signal (SRS), a channel state information-reference signal (CSI-RS), a demodulation reference signal (DM-RS), a phase tracking reference signal (PTRS), or a synchronization signal block (SSB). When referred to herein, a channel may include a PDCCH, a PDSCH, a Physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a physical random access channel (PRACH), etc. The terms signal, channel, and message (e.g., as in DL or UL signal, channel, or message) may be used interchangeably herein. The term RS resource set may be interchangeably used herein with the term RS resource or beam group. The term beam reporting may be interchangeably used herein with the term CSI measurement, CSI reporting, or beam measurement. When described herein, a beam resource prediction technique may be applied to beam resources that may belong to a single cell or multiple cells, a single or multiple TRPs, etc. The term CSI reporting may be used interchangeably herein with the term CSI measurement, beam reporting, or beam measurement. The term RS resource set may be used interchangeably herein with the term beam group. When used herein, the term HAORAP (HARQ- ACK overhead reduction procedure) may refer to techniques, solutions and/or procedures associated with reducing the overhead associated with HARQ-ACK transmissions in some examples. The techniques described in the examples related to activating, deactivating, and/or applying a HAORP may also be used in other procedures, actions, services, functions, events, etc. The term "HARQ-ACK overhead reduction procedure” or “HAORP” may include procedures, actions, services, functions, events, and/or the like.

[0095] A WTRU may be configured with one or more resource allocations for uplink transmissions (e.g., data channels) in one or more transmission occasions. For example, for a control channel transmission (e.g., PUCCH), a resource allocation or configuration may include one or more settings or parameters, such as a starting PRB, a second hop starting PRB, a number of PRBs, a number of slots, a starting symbol index, a PUCCH format, a cyclic shift, an orthogonal cover code (OCC) configuration, and/or the like that may be indicated based on a PUCCH resource index or indicator (e.g., such as a PUCCH- Resourceld).

[0096] In examples, for a downlink (shared) channel transmission (e.g., PDSCH) configured by semistatic indications (e.g., SPS PDSCH configured by SPS-Config), the WTRU may determine or be configured with an associated PUCCH resource index or indicator that the WTRU may use to send corresponding control information (e.g., HARQ-ACK, CSI report, etc.). For instance, the time resources (e.g., slots) for the transmission of a HARQ-ACK in a respective PUCCH may be defined based on one or more RRC-configured parameters (e.g., a K1 defined via dl-DataToUL-ACK of PUCCH-Config in BWP- UplinkDedicated), or activated via DCI (e.g., format 1_1 or 1_2 with a PDSCH-to-HARQ_feedback timing indicator field).

[0097] In examples, for an uplink shared channel transmission (e.g., PUSCH), a resource allocation or configuration may be indicated based on one or more settings or parameters, such as time resources (e.g., timeDomainAllocation), frequency resources (e.g., frequencyDomainAllocation), a periodicity, a repetition, etc. For example, for a PUSCH transmission corresponding to a first configured grant (e.g., Type 1) or for a PUSCH transmission corresponding to a second configured grant (e.g., Type 2) and activated by DCI, a resource allocation may be provided by one or more parameters (e.g., via ConfiguredGrantConfig in BWP- UplinkDedicated and/or an activating UL grant received via DCI).

[0098] For a PUSCH transmission corresponding to an UL grant (e.g., a dynamic grant), a time domain resource assignment (TDRA) (e.g., received in DCI) may indicate a slot offset (e.g., K2 via a indexed row), a start and length indicator (e.g., SLIV), a start symbol and/or allocation length, a PUSCH mapping type, the number of slots for a transport block size (TBS) determination, and/or the number of repetitions for the PUSCH transmission.

[0099] A WTRU may be configured with one or more PUCCH resource sets, including one or more PUCCH resources. In examples, PUCCH resource configure parameters may include a PUCCH resource index, an index for a first PRB, an index for a first PRB for frequency hopping, a PUCCH format, a starting symbol index, a number of symbols, a number of PRBs, and/or the like.

[0100] A WTRU may be configured with a PUCCH resource indicator (PRI) field (e.g., via DCI). In examples, the PRI may be indicated by one or more bits (e.g., up to three bits), where the PRI may map to a set of PUCCH resource indices corresponding to multiple (e.g., up to eight) PUCCH resources provided by a PUCCH resource set. The WTRU may use the PRI to determine the resource allocation to be used for a PUCCH transmission.

[0101] A WTRU may receive configuration information regarding the time and/or frequency resources for transmitting HARQ ACK/NACK feedback. The HARQ ACK/NACK timing for the reception of a downlink signal and/or channel may be configured, for example, by one or more higher layer parameters (e.g., K1). In examples, a K1 parameter may indicate an index in a table specified by an RRC parameter (e.g., dl- DataToUL-ACK in PUCCH-Config), as shown below in the non-limiting examples of parameters that may be included in PUCCH configuration information. One or more of the shown parameters may be included. The number of bits and/or choices for each parameter are merely examples and other numbers of bits and/or choices may be included.

PUCCH-Config ::= SEQUENCE { resourceToAddModList SEQWTRUNCE (SIZE (1..maxNrofPUCCH-Resources)) OF PUCCH- Resource dl-DataToUL-ACK SEQUENCE (SIZE (1..8)) OF INTEGER (0..15) Optional

} maxNrofPUCCH-Resources INTEGER ::= 128

[0102] A WTRU may receive one or more reference signals and/or channel transmissions (e.g. in the downlink). The WTRU may receive configuration information associated with generating one or more HARQ-ACK information bits and/or HARQ-ACK codebooks. In an example, the WTRU may report HARQ- ACK information for one or more PDSCH receptions, one or more PDCCH (e.g., DCI) receptions, one or more TCI state updates, a PDSCH transmission without a corresponding PDCCH, a PDCCH transmission indicating a SPS PDSCH release, and/or the like. The WTRU may report the HARQ-ACK information bits in a HARQ-ACK codebook (e.g., Type-1, Type-2, Type-3, etc.) that the WTRU may transmit in a slot indicated by a timing indicator (e.g., a PDSCH-to-HARQ feedback timing indicator field in a corresponding DCI format). In an example, the WTRU may determine if the resources for a HARQ-ACK report are mapped to a PUCCH or PUSCH.

[0103] The WTRU may determine 6Q ^CK, O^^CK, ... , O^K-I HARQ-ACK information bits for a total number of O_ACK HARQ-ACK information bits. The WTRU may be configured with one or more HARQ- ACK codebook indices for multiplexing the corresponding HARQ-ACK information bits (e.g., per SPS PDSCH configuration).

[0104] The WTRU may determine the total number of transport blocks (TBs) or code block groups (CBGs) to be received based on one or more configurations and/or one or more DCI (e.g., comprising a grant) indications received by the WTRU. In an example, the WTRU may be indicated or configured to receive one or more PDSCH downlink transmissions. The WTRU may use a total downlink assignment index (DAI) field in a UL grant DCI to determine the total number of TBs or CBGs to be received.

[0105] A HARQ codebook may be transmitted via a one-shot transmission (e.g., delay and/or accumulate HARQ information and transmit the delayed/accumulated HARQ information at once). As described herein, a WTRU may determine to enable, use, or activate an HAORP based on an AI/ML model, a measurement performed by the WTRU, or an indication (e.g., an explicit indication) from a base station. The WTRU may determine to transmit a HARQ codebook (e.g., comprising TB-based HARQ feedback information followed by partial CBG-based HARQ feedback information) associated with DL transmissions in a one-shot transmission (e.g., delay HARQ feedback until the one-shot transmission) over one or more carriers. One or more of these operations may result in power saving and/or avoidance of frequent switching between the DL and UL.

[0106] The WTRU may send a message to the base station (e.g., as part of a CSI report or HARQ-ACK transmission) and may indicate (e.g., via a flag or a bit field) a request for enabling a one-shot transmission of a HARQ codebook and/or a carrier associated with the request. The WTRU may receive a confirmation or an indication from the base station (e.g., via a PDCCH transmission) to enable delayed transmission of HARQ-ACK feedback until the one-shot transmission of the HARQ codebook. The confirmation or indication from the base station may indicate a carrier for which the one-shot HARQ codebook transmission is configured/confirmed. The confirmation or indication from the base station may include a non-numerical (NN) K1 value (e.g., also referred to herein as an invalid K1 value) that may indicate an invalid or empty resource allocation. [0107] The enablement of the one-shot transmission of the HARQ codebook (e.g., delayed HARQ-ACK feedback) may be provided via an explicit indication such as a field in DCI indicating that the base station has accepted the request from the WTRU to enable the one-shot transmission. The enablement may also be provided implicitly, e.g., via a PUCCH resource indicator. For example, a value of 0 in such an indicator may indicate that no PUCCH resources has been allocated for HARQ feedback or that the base station has accepted the one-shot HARQ-ACK transmission. As another example, an invalid K1 value in such an indicator may indicate that the base station has accepted the one-shot HARQ feedback transmission.

[0108] The WTRU may receive a grant or configuration (e.g., via DCI) associated with the reception of a PDCCH, SPS-PDSCH, TCI state update, dynamic grant for PDSCH, etc. The grant or configuration may include corresponding HARQ-ACK/NACK parameters such as a HARQ process ID, a HARQ codebook type, spatial bundling, CBG transmissions, etc. The WTRU may receive scheduled DL transmissions and may determine HARQ feedback bits or codebooks (e.g., based on the codebook generation techniques described herein) corresponding to the DL transmissions. The WTRU may decide not to transmit the HARQ feedback or codebooks and instead to buffer or store TB-based HARQ feedback (e.g., a bitmap as a first part of the codebook) and/or CBG-based HARQ feedback (e.g., as a second part of the codebook). If the WTRU receives a PDCCH transmission (e.g., a grant DCI) with a valid K1 value, the WTRU may stop the buffering of the HARQ feedback (e.g., HARQ codebook) and use the corresponding PUCCH resources to transmit the stored/buffered HARQ feedback (e.g., HARQ codebook). The WTRU may determine and/or indicate to the base station that the buffering of the HARQ codebook may be deactivated or stopped for the one-shot HARQ transmission. The deactivation may be based on one or more of an AI/ML model, a buffer size (e.g., the WTRU may determine that there may not be enough buffer space left), or an RTT (e.g., the WTRU may determine that further delaying of HARQ-ACK/NACK transmission may exceed a configured maximum RTT). With the AI/ML model, the WTRU may predict and/or determine (e.g., based on base station indications) that consecutive ACKs may no longer be possible and/or that the number of NACKs may be increasing. As a result, HARQ feedback should no longer be delayed. The deactivation indication (e.g., to stop the buffering of HARQ-ACK/NACK and perform a one-shot transmission of the HARQ-ACK codebook) may include a flag or bit field (e.g., as part of a CSI report). The indication may serve as a scheduling request for transmission of the HARQ codebook.

[0109] The HAORP described herein may include transmission (e.g., a one-shot transmission) of a HARQ codebook (e.g., the enhanced HARQ-ACK codebook described herein) by a WTRU. Such a HARQ codebook may include two or more parts or components. A first part or component of the codebook may include bundled HARQ feedback. A second part or component of the codebook may include more granular (e.g., more granular than the first part or component of the codebook) HARQ feedback. The granularity of the first or second part of the codebook may be at a CBG level, a TB level, a bundled TB level (e.g., multiple TBs bundled together), or a time period level (e.g., allocations in a set of time periods or slots, bundled together). For example, the WTRU may be configured to report TB-level HARQ feedback in the first part of the codebook and report CBG-level HARQ feedback in a second part of the codebook. As another example, the WTRU may be configured to report bundled TB HARQ feedback (e.g., HARQ feedback for a set of TBs) in the first part of the codebook and report TB-level HARQ feedback in the second part of the codebook.

[0110] One or more elements in the second part or component of the HARQ codebook may be associated with an element in the first part or component of the HARQ codebook. For example, the first part of the HARQ codebook may provide TB-level HARQ feedback, the second part of the HARQ codebook may provide CBG-level HARQ feedback, and a (e.g., each) TB-level HARQ element in the first part or component of the HARQ codebook may be associated with a set of CBG-level HARQ-ACK elements in the second part or component of the HARQ codebook. If an ACK is determined for a TB in the first part or component of the HARQ codebook, an ACK may also be determined for one or more (e.g., all) CBGs associated with the TB in the second part or component of the HARQ codebook. If an NACK is determined for the TB in a first part or component of HARQ codebook, then the second part or component of the HARQ codebook may include an NACK for at least one CBG associated with the TB.

[0111] The WTRU may select or determine a bundling granularity for the first or second part or component of the HARQ codebook. The WTRU may determine the bundling granularity based on (e.g., as a function of) at least one of a feedback overhead reduction requirement, a feedback performance requirement, a channel condition, a HARQ-ACK operating point, a feedback latency, a retransmission latency, or previous performance of the WTRU. With respect to the feedback overhead reduction requirement, the WTRU may select the bundling granularity for the first or second part of the HARQ codebook to minimize the feedback overhead (e.g., by using the largest achievable bundling granularity). With respect to the feedback performance requirement, the WTRU may select a bundling granularity that may reduce unnecessary retransmissions. With respect to the channel condition, the WTRU may select a bundling granularity based on (e.g., as a function of) a measured (e.g., currently measured) or predicted channel condition. For example, the WTRU may determine or predict that a set of subsequent slots may experience similar channel conditions and/or HARQ-ACK performance. As a result, the WTRU may bundle transmissions in that set of slots into a single feedback element. With respect to the HARQ-ACK operating point, the WTRU may select a bundling granularity based on (e.g., as a function of) an expected rate of NACKs. With respect to the feedback latency, the WTRU may select a bundling granularity based on a permissible latency to deliver the feedback. With respect to the retransmission latency, the WTRU may select a bundling granularity based on the timing of a feedback report and/or a retransmission latency provided by the network or an application. With respect to the previous performance of the WTRU, the WTRU may select a bundling granularity based on the feedback performance of a previously selected bundling granularity, wherein the feedback performance may be measured based on a retransmission latency, a feedback latency, a rate or number of unnecessary retransmissions, and/or overhead associated with the feedback.

[0112] A WTRU may determine or be triggered to use or stop using the new or enhanced HARQ codebook described herein. The triggers may include at least one of an indication from a base station, a prediction of future HARQ transmissions by the WTRU, a transmission requirement, or a HARQ reporting requirement. The indication from the base station may be received by the WTRU via RRC signaling, a MAC CE, or DCI. The indication may be implicit (e.g., indicated by the use of multiple resources each associated with a part or component of the codebook, or by the assignment of a non-numeric or invalid feedback resource). The indication may indicate time-frequency or spatial resources, a BWP or carrier with which the indication is associated, etc. With respect to the prediction of future HARQ-ACK transmissions, the WTRU may determine that future HARQ-ACK/NACK performance may be stable and thus the WTRU may use bundling or a specific bundling granularity. With respect to the transmission requirement, the WTRU may determine, based on latency and/or a BLER, whether or not to use the HARQ codebook described herein. For example, the WTRU may determine the type of HARQ codebook to use (e.g., enhanced or legacy) based on (e.g., as a function of) the priority of a transmission. With respect to the HARQ reporting requirement, the WTRU may determine to use the HARQ codebook described herein based on (e.g., as a function of) a HARQ operating point, a latency requirement, and/or the like.

[0113] The WTRU may indicate to a base station one or more parameters associated with the enhanced HARQ codebook described herein. For example, the WTRU may indicate to the base station when the HARQ codebook may be used or when the HARQ codebook may not be used. The WTRU may send a request to the base station to use or stop using the HARQ codebook. The indication or request may be accomplished using dedicated resources, via a CSI report, via a MAC CE, and/or via a previous HARQ feedback report. With respect to the dedicated resources, the WTRU may be configured with resources dedicated to reporting parameters (or an update thereof) associated with the HARQ codebook. For example, the WTRU may be configured with resources dedicated to reporting the use or non-use of the HARQ codebook. With respect to the CSI report, the WTRU may indicate, in the CSI report, a request to use or stop using the HARQ codebook. The WTRU may also indicate the parameters associated with the HARQ codebook in the CSI report. With respect to the previous HARQ feedback report, the WTRU may indicate, in that HARQ feedback report, the parameters associated with the HARQ codebook to be transmitted subsequently or an indication/request to use or stop using the HARQ codebook for a subsequent HARQ feedback report. The indication sent by the WTRU to the base station may indicate time-frequency or spatial resources, carrier(s), or BWP(s) for which the indication may be valid.

[0114] The contents of a part or component of the HARQ codebook described herein may depend on the contents of another part or component of the HARQ codebook. For example, the first part or component of the HARQ codebook may indicate a set of ACKs or NACKs at a first granularity level (e.g., TB-based ACK/NACK), and that granularity level may be used to determine a granularity level for the second part or component of the HARQ codebook (e.g., CBG-based ACK/NACK, wherein the CBGs may be associated with a TB of the first part or component of the HARQ codebook). The WTRU may include, in the second part or component of the HARQ codebook, HARQ feedback for a set of units (e.g., CBGs) that may be associated with a set of units (e.g., a TB) NACKed in the first part or component of the HARQ codebook. For example, the first part or component of the HARQ codebook may include HARQ feedback for a bundle of TBs, and the second part or component of the HARQ codebook may include HARQ feedback for individual TBs. In this example, a first element of the first part or component of the HARQ codebook may represent a HARQ-ACK/NACK for first x bundled TBs and a second element of the first part or component of the HARQ codebook may represent a HARQ-ACK/NACK for second x bundled TBs. If the first element is an ACK and the second element is an NACK, the WTRU may determine that the second part or component of the HARQ codebook may include (e.g., may only include) HARQ-ACK/NACK for TBs that are among the second set of x TBs (e.g., which are NACKed in the first part of the HARQ codebook). As another example, if a WTRU is not triggered to report the first part or component of the HARQ codebook but is triggered to report the second part or component of the HARQ codebook, the WTRU may report HARQ feedback information (e.g., all elements) from the second part or component of the HARQ codebook, regardless of the unreported HARQ feedback (e.g., from the first part or component of the HARQ codebook).

[0115] A WTRU may be configured with resources to report one or multiple parts or components of the HARQ codebook described herein. The WTRU may determine the resources for transmitting a second part or component of the HARQ codebook based on (e.g., as a function of) the contents of a first part or component of the HARQ codebook. The WTRU may be configured with resources to transmit the first part or component of the HARQ codebook (e.g., the first part or component of the HARQ codebook may include one or more elements based on a first bundling granularity). The WTRU may be configured with resources to transmit the second part or component of the HARQ codebook that may be associated with the first part or component of the HARQ codebook. For example, the WTRU may be configured to report n (e.g., consecutive) first component HARQ codebooks and, with a (n+1 )th reporting resource, the WTRU may include a (n+1 )th first component HARQ codebook and a second component HARQ codebook that may be associated with one of the first n component HARQ codebooks or the (n+1 )th first component HARQ codebook. As another method, the WTRU may be configured with a resource for the first part or component of the HARQ codebook (e.g., via a k1 value in a DCI or a first PUCCH feedback resource) and a resource for the second part or component of the codebook (e.g., via a kT value in a DCI or a second PUCCH feedback resource). The resources (e.g., indicated by the k1 or k1 ’ value) may have a nonnumeric or invalid value, in which case the WTRU may store the corresponding part or component of the HARQ codebook until the WTRU is triggered (or polled) to transmit it by the base station. The WTRU may determine an index associated with a part or component of the HARQ codebook and may be triggered to report the part or component of the codebook via an indication (e.g., in DCI) that may include the index.

[0116] If the WTRU is indicated (e.g., triggered) by the base station to report a second part or component of the HARQ codebook whose contents or size may depend on a first part or component of the HARQ codebook, the indication may also include an expected size of the second part or component of the codebook. This may ensure common understanding by the base station and the WTRU with respect to the contents of the second part or component of the codebook. If the indicated size of the second part or component of the codebook is not a value expected by the WTRU, the WTRU may report an error, report the second part or component of the codebook up to the size indicated, or report a complete second part or component of the codebook (e.g., independent of the contents of the first part or component of the codebook).

[0117] The terms “HARQ codebook,” “HARQ-ACK codebook,” “HARQ-ACK/NACK codebook,” “HARQ- ACK codebook type x,” “new HARQ codebook” and “enhanced HARQ codebook” may be used interchangeably herein.

[0118] A WTRU may receive configuration information regarding a one-shot transmission of the HARQ codebook described herein from a base station. The WTRU may assume that the one-shot HARQ codebook transmission is activated by default if the WTRU is configured with the one-shot transmission). In one example approach, the WTRU may start performing the one-shot HARQ codebook transmission upon being configured. In another example approach, the WTRU may wait for a subsequent activation indication from the base station before starting to perform the one-shot HARQ codebook transmission. The subsequent activation indication from the base station may trigger the WTRU to apply the configuration associated with one-shot HARQ codebook transmission.

[0119] The WTRU may be configured to perform one or more of the actions described herein upon applying/activating the configuration associated with the one-shot HARQ codebook transmission. The WTRU may receive a grant or configuration for reception of a PDCCH, an SPS-PDSCH, a TCI state update, etc. The WTRU may receive a dynamic grant for a PDSCH. The grant or configuration may include corresponding HARQ-ACK/NACK parameters, including a HARQ process ID, a HARQ codebook type, a type of spatial bundling, a code block group (CBG) transmission, etc. The WTRU may receive scheduled DL data and may determine corresponding HARQ feedback according to the HARQ codebook described herein. For example, the WTRU may buffer and/or store a TB-based HARQ bitmap (e.g., as a first part of the HARQ codebook) and/or CBG-based HARQ feedback (e.g., as a second part of the HARQ codebook). While performing these actions, the WTRU may not transmit a legacy HARQ codebook and may assume that PUCCH resources for legacy HARQ transmission may be deactivated or unavailable. [0120] Triggers may be configured for deactivating or stopping the use of the HARQ codebook described herein. A WTRU may be configured to determine (e.g., autonomously) one or more behaviors that may be associated with the buffering of the HARQ codebook described herein for a one-shot HARQ codebook transmission. For example, the WTRU may be configured to determine if the buffering of the HARQ codebook for a one-shot HARQ codebook transmission should be deactivated. The WTRU may be configured with conditions to trigger the activation/deactivation of the one-shot HARQ codebook transmission. For example, the WTRU may trigger the deactivation of the one-shot transmission based on (e.g., as a function of) a buffer status of the WTRU. As another example, the WTRU may trigger the deactivation of the one-shot transmission if a remaining buffer (e.g., soft buffer) size of the WTRU is below a preconfigured threshold. As yet another example, the WTRU may trigger the deactivation of the one-shot transmission if the remaining buffer (e.g., soft buffer) of the WTRU is not enough to accommodate data associated with DL transmissions. One or more of these determinations may be made based on (e.g., as a function of) the WTRU’s capabilities.

[0121] In examples, the WTRU may trigger the deactivation of the one-shot HARQ transmission based on (e.g., as a function of) a Round-Trip Time (RTT). The WTRU may be configured with maximum, acceptable, or allowable RTTs, for example, as a function of different service requirements. The WTRU may trigger a deactivation of the one-shot HARQ transmission if the RTT of the oldest buffered HARQ process exceeds a configured RTT threshold. The WTRU may trigger the deactivation if a preconfigured number of HARQ processes have RTTs that exceed a configured RTT threshold. The threshold(s) may be configured such that the WTRU may recover from a condition where the delaying of HARQ transmissions (e.g., for feedback overhead reduction) may lead to an increased RTT that may negatively affect the quality of service.

[0122] The WTRU may be configured to determine one or more behaviors associated with the one-shot transmission of the HARQ codebook described herein based on the output of an AI/ML model. For example, the WTRU may be configured with an AI/ML model to predict the probability of successful decoding at a future time instance. The AI/ML model may predict the probability of a number of consecutive ACKs in a future time interval being below a threshold. The WTRU may determine the probability of a number of NACKs in a future interval being above a threshold. The WTRU may determine the optimal HARQ codebook type (e.g., the codebook described herein or a legacy codebook) to apply based on predicted channel conditions at a future time instance. The WTRU may deactivate the use of the HARQ codebook described herein based on the output of the AI/ML model. For example, the WTRU may infer from a prediction output of the AI/ML model that the HARQ codebook may lead to increased delay and the WTRU may trigger the deactivation accordingly. The inputs to the AI/ML model described herein may be configured. For example, the WTRU may input the current and/or historical channel measurements (e.g., including but not limited to a raw channel matrix, eigenvector(s) of a channel, CSI, RSRP, RSRQ, SI NR, etc.), WTRU speed/doppler, current and/or historical BLER, ACK/NACK, HARQ buffer status, configuration aspects of one-short transmissions of HARQ feedback, the HARK-ACK codebook described herein, etc.

[0123] The term “deactivation indication” and “deactivation request” may be used interchangeably herein. If one or more trigger conditions for deactivation of the HARQ-ACK codebook described herein are satisfied, the WTRU may indicate or send a request to the base station to deactivate or stop the buffering of the HARQ feedback. The WTRU may be configured to transmit the deactivation indication using one or more of the following methods. In a first example, the WTRU may transmit the deactivation indication using one or more preconfigured bits in a CSI report. For example, the WTRU may include a flag in the CSI report to indicate a deactivation request for the HARQ-ACK codebook or the one-shot transmission of the HARQ codebook. The deactivation indication may be carried in any part of the CSI report. The WTRU may be configured with SR-PUCCH resources dedicated for the transmission of the deactivation indication. The WTRU may, based on the satisfaction of one or more trigger conditions described herein, transmit the deactivation indication in the configured SR-PUCCH resources.

[0124] The WTRU may be configured to transmit the deactivation indication in the earliest occurring UL opportunity. For example, the WTRU may transmit the deactivation indication in a PUSCH resource if it occurs earlier than a PUCCH resource, a CSI reporting resource, or an SR resource. The WTRU may transmit the deactivation indication in a MAC CE.

[0125] The WTRU may be configured to deactivate one-shot transmission of the HARQ-ACK codebook described herein based on an indication from the base station. For example, the WTRU may be configured to deactivate the one-shot HARQ transmission upon receiving a PDCCH with a valid value of K1. Upon the deactivation of the one-shot transmission, the WTRU may stop buffering HARQ feedback associated with the HARQ codebook and transmit the stored/buffered HARQ codebook using a PUCCH resource. After the transmission, the WTRU may resume the buffering of HARQ feedback associated with the HARQ-ACK codebook (e.g., the deactivation from the base station may be one-shot). The WTRU may use PUCCH resources for a legacy HARQ codebook or legacy HARQ feedback upon deactivation of the HARQ codebook described herein.

[0126] The WTRU may treat a deactivation indication from the base station as semi-static. For example, in response to receiving deactivation indication, the WTRU may suspend the use of the HARQ codebook described herein and use a legacy HARQ codebook for subsequent HARQ feedback. The WTRU may resume using the HARQ codebook described herein upon receiving an indication (e.g., an explicit indication) from the base station, such as, for example, an invalid/predefined K1 value in DCI and/or a MAC CE.

[0127] The WTRU may receive a grant and/or activation of a UL resource for transmitting the HARQ codebook described herein. Such a grant or activation of the UL resource may be signaled along with a deactivation indication from the base station. Upon receiving such a grant or activation, the WTRU may perform a one-shot transmission of the HARQ codebook generated/buffered thus far (e.g., before the deactivation indication) to the base station using one or more of the methods described herein.

[0128] A WTRU may perform a one-shot transmission of the HARQ codebook described herein (e.g., a new or enhanced HARQ codebook). The WTRU may enable/disable, use/stop using, or activate/deactivate a HAORP (e.g., based on an AI/ML model, a measurement, or an explicit indication from a base station). If the HAORP enablement/disablement decision is made by the WTRU, the WTRU may send an indication to the base station regarding the decision (e.g., via a CSI report or a HARQ- ACK/NACK transmission). The WTRU may, for example, send a flag or indication to the base station requesting enablement of a one-shot transmission of the HARQ codebook. The WTRU may also indicate to the base station the carrier for which the HAORP is requested. If the HAORP decision is made by the base station, the WTRU may receive an indication from the base station to enable (or disable) the HAORP. The indication may indicate a carrier to which the HAORP may be related. The indication may be provided explicitly, e.g., via a reserved field in DCI, to inform the WTRU that the base station has accepted the HAORP request. The indication may be provided implicitly, e.g., via a PUCCH resource indicator or a K1 value. For example, a PUCCH resource indicator of 0 may indicate that no PUCCH resource has been allocated for HARQ and/or that the base station has accepted a one-shot HARQ feedback transmission. An invalid K1 value may also indicate that the base station has accepted the one-shot HARQ feedback transmission.

[0129] The WTRU may receive scheduling information to enable reception of one or more transmissions for which the WTRU may report a HARQ-ACK/NACK. The scheduling information may include one or more K1 values. If the WTRU is scheduled with a single K1 value, the WTRU may determine the resources with which to report the HARQ-ACK/NACK for the scheduled one or more transmissions based on the value of K1 . If the WTRU is scheduled with two K1 values, the WTRU may determine the resources with which to report a first set of HARQ-ACK/NACK bits based on the first K1 value, and determine the resources with which to report a second set of HARQ-ACK/NACK bits based on the second K1 value.

[0130] The WTRU may build a two-part HARQ codebook (e.g., a first set of HARQ bits corresponding to TB-based HARQ of one or more received transmissions, and a second set of HARQ bits corresponding to CBG-based HARQ for at least a subset of the one or more received transmissions). The WTRU may report the first set of HARQ bits using resources determined from a first K1 value. The WTRU may report the second set of HARQ bits using resources determined from the first K1 value (e.g., if the WTRU is scheduled with a single K1 value), or resources determined from a second K1 value (e.g., if the WTRU is scheduled with a second K1 value with a numeric or valid value). The WTRU may keep the second set of HARQ bits in a buffer (e.g., if the WTRU is scheduled with a non-numeric or invalid K1 value). If the WTRU buffers the second set of HARQ bits, the WTRU may determine whether to provide feedback associated with the second set of HARQ bits based on an AI/ML model, a measurement, a buffer size, and/or a roundtrip time (RTT). With the AI/ML model, the WTRU may predict and/or determine (e.g., based on an indication from a base station) that a situation with consecutive ACKs may no longer be possible and/or that the number of NACKs may be increasing. With the buffer size, the WTRU may determine that its buffer space may be limited. With the RTT, the WTRU may determine that a further delay of the HARQ transmission may exceed a configured RTT (e.g., a maximum RTT). The WTRU may transmit a request to report the second set of HARQ bits, for example, via a scheduling request.

[0131] 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. 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.

[0132] 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 is:

1. A wireless transmit/receive unit (WTRU), comprising: a processor configured to: receive an indication from a network device that the WTRU is to delay hybrid automatic repeat request (HARQ) transmissions; receive a first downlink transmission; store a first HARQ feedback for the first downlink transmission based on the indication to delay the HARQ transmissions; receive a second downlink transmission; store a second HARQ feedback for the second downlink transmission based on the indication to delay the HARQ transmissions; determine that a condition for transmitting the first HARQ feedback and the second HARQ feedback is met; and transmit the first HARQ feedback and the second HARQ feedback via a HARQ codebook based on the determination that the condition for transmitting the first HARQ feedback and the second HARQ feedback is met.

2. The WTRU of claim 1, wherein the processor is configured to receive the indication to delay the HARQ transmissions via downlink control information (DCI) from the network device.

3. The WTRU of claim 2, wherein the DCI includes an explicit indication that the WTRU is to delay the HARQ transmissions.

4. The WTRU of claim 2, wherein the DCI includes a resource indicator or a HARQ time gap indicator that implicitly indicates that the WTRU is to delay the HARQ transmissions.

5. The WTRU of claim 1, wherein the processor being configured to determine that the condition for transmitting the first HARQ feedback and the second HARQ feedback is met comprises the processor being configured to receive downlink control information (DCI) from the network device and determine, based on a HARQ parameter included in the DCI, that the condition for transmitting the first HARQ feedback and the second HARQ feedback is met.

6. The WTRU of claim 5, wherein the HARQ parameter indicates a time gap associated with HARQ feedback.

7. The WTRU of claim 5, wherein the DCI indicates one or more uplink transmission resources for the WTRU, and wherein the processor is configured to transmit the first HARQ feedback and the second HARQ feedback using the one or more uplink transmission resources.

8. The WTRU of claim 1, wherein the processor is further configured to determine that HARQ feedback delay is to be deactivated and transmit a request to the network device to deactivate the HARQ feedback delay.

9. The WTRU of claim 8, wherein the request is included in a channel state information (CSI) report or a scheduling request transmitted to the network device.

10. A method implemented by a wireless transmit/receive unit (WTRU), the method comprising: receiving an indication from a network device that the WTRU is to delay hybrid automatic repeat request (HARQ) transmissions; receiving a first downlink transmission; storing a first HARQ feedback for the first downlink transmission based on the indication to delay the HARQ transmissions; receiving a second downlink transmission; storing a second HARQ feedback for the second downlink transmission based on the indication to delay the HARQ transmissions; determining that a condition for transmitting the first HARQ feedback and the second HARQ feedback is met; and transmitting the first HARQ feedback and the second HARQ feedback in a HARQ codebook based on the determination that the condition for transmitting the first HARQ feedback and the second HARQ feedback is met.

11 . The method of claim 10, wherein the indication to delay the HARQ transmissions is received via downlink control information (DCI) from the network device.

12. The method of claim 11 , wherein the DCI includes a data field that explicitly indicates that the WTRU is to delay the HARQ transmissions, or a resource indicator or a HARQ time gap indicator that implicitly indicates that the WTRU is to delay the HARQ transmissions.

13. The method of claim 10, wherein determining that the condition for transmitting the first HARQ feedback and the second HARQ feedback is met comprises receiving downlink control information (DCI) from the network device and determining, based on a HARQ parameter included in the DCI, that the condition for transmitting the first HARQ feedback and the second HARQ feedback is met.

14. The method of claim 13, wherein the DCI indicates one or more uplink transmission resources for the WTRU, and wherein the first HARQ feedback and the second HARQ feedback are transmitted to the network device using the one or more uplink transmission resources.

15. The method of claim 10, wherein further comprising determining that HARQ feedback delay is to be deactivated and transmit a request to the network device to deactivate the HARQ feedback delay.