Method and apparatus for uplink control enhancements

Abstract

Methods and apparatus for uplink control enhancements in wireless communications are disclosed. In an example, a method includes receiving information related to a set of downlink SPS configurations, receiving a downlink SPS transmission based on the received information, determining a payload of UCI for transmission on an uplink channel, the payload including a set of HARQ feedback bits based on the received information, determining that at least one triggering condition for partitioning the set of HARQ feedback bits is satisfied, determining at least a portion of the set of HARQ feedback bits based on at least a downlink SPS configuration of the set of downlink SPS configurations, wherein the determined portion of the set of HARQ feedback bits corresponds to a respective subset of the received one or more downlink SPS transmissions, and transmitting at least the determined portion of the set of HARQ feedback bits using the uplink channel.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Application No. 62 / 975,753, filed February 12, 2020, in the U.S. Patent and Trademark Office, and U.S. Provisional Application No. 63 / 091,653, filed October 14, 2020, in the U.S. Patent and Trademark Office, the entire contents of each of which are incorporated herein by reference as if fully set forth below in their entirety for all purposes. SUMMARY

[0003] The embodiments disclosed herein generally relate to wireless and / or wired communication networks. For example, one or more embodiments disclosed herein relate to methods and apparatuses for uplink control enhancements in wireless communications.

[0004] In one embodiment, a method implemented by a wireless transmit / receive unit (WTRU) for wireless communications includes receiving information related to a set of downlink semi-persistent scheduling (SPS) configurations and receiving one or more downlink SPS transmissions based on the received information. The method includes determining a payload of uplink control information (UCI) for transmission on an uplink channel, and the payload includes a set of hybrid automatic repeat request (HARQ) feedback bits based on the received information. The method further includes determining that at least one trigger condition for partitioning the set of HARQ feedback bits is satisfied and determining at least a portion of the set of HARQ feedback bits based on at least a downlink SPS configuration of the set of downlink SPS configurations, wherein the determined portion of the set of HARQ feedback bits corresponds to a respective subset of the received one or more downlink SPS transmissions. The method further includes transmitting the determined portion of the set of HARQ feedback bits using the uplink channel. BRIEF DESCRIPTION OF DRAWINGS

[0005] A more detailed understanding can be had from the following detailed description, given by way of example in conjunction with the accompanying drawings wherein:

[0006] Figure 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments can be implemented;

[0007] Figure 1B is a diagram illustrating an example wireless transmit / receive unit (WTRU) that can be used within the communications system of FIG. 1, according to an embodiment; Figure 1ASystem diagram of an exemplary radio access network (RAN) and exemplary core network (CN) for use within the illustrated communication system;

[0008] Figure 1C is a block diagram illustrating an example of HARQ feedback / HARQ codebook splitting according to one or more embodiments; Figure 1A System diagram of an exemplary radio access network (RAN) and exemplary core network (CN) for use within the illustrated communication system;

[0009] Figure 1D is a block diagram illustrating an example of HARQ feedback / HARQ codebook splitting according to one or more embodiments; Figure 1A System diagram of another exemplary RAN and another exemplary CN for use within the illustrated communication system;

[0010] Figure 2 is a block diagram illustrating an example of HARQ feedback / HARQ codebook splitting according to one or more embodiments;

[0011] Figure 3 is a block diagram illustrating an example of HARQ feedback / HARQ codebook splitting and mapping to different physical uplink control channel (PUCCH) resources according to one or more embodiments;

[0012] Figure 4 is a block diagram illustrating an example of HARQ feedback / HARQ codebook splitting and skip indication using extension bits according to one or more embodiments; and

[0013] Figure 5 is a block diagram illustrating an example of HARQ feedback reduction mechanism for multiple downlink semi-persistent scheduling (SPS) configurations according to one or more embodiments. DETAILED DESCRIPTION

[0014] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the implementations and / or examples disclosed herein. However, it will be understood that such implementations and examples can be practiced without some or all of these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the following description. Also, implementations and examples not specifically described herein can be implemented and / or practiced using the descriptions and / or teachings contained in the present disclosure and associated drawings. Although various implementations are described and / or claimed herein, it will be understood that any implementation described and / or claimed herein can be implemented and / or practiced using any other implementation described and / or claimed herein.

[0015] Communication networks and devices

[0016] The methods, apparatus and systems provided herein are well suited to communications involving both wired networks and wireless networks. Wired networks are well known. In contrast, Figures 1A-1D A variety of types of wireless devices and infrastructure are provided, where various elements of the network can utilize, perform, be arranged in accordance with, and / or be adapted and / or configured for the methods, apparatus and systems provided herein.

[0017] Figure 1A is a schematic diagram illustrating an example communications system 100 in which one or more disclosed implementations can be implemented. The communications system 100 can be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 can enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 can 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-filter OFDM, filter bank multicarrier (FBMC), and / or the like.

[0018] As Figure 1AAs shown, the communication system 100 can include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d can 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 can be referred to as a "station" and / or a "STA") can be configured to transmit and / or receive wireless signals, and can include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain environment), a consumer electronics device, a device operating on a commercial and / or industrial wireless network, and the like. Any of the WTRUs 102a, 102b, 102c, and 102d can be interchangeably referred to as a UE.

[0019] The communication system 100 can also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b can 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 can be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a new radio (NR) Node B, 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 can include any number of interconnected base stations and / or network elements.

[0020] The base stations 114a can be part of the RAN 104 / 113, which can 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 stations 114a and / or the base stations 114b can be configured to transmit and / or receive wireless signals on one or more carrier frequencies (which can be referred to as a cell (not shown)). These frequencies can be in the licensed spectrum, the unlicensed spectrum, or a combination of the licensed and unlicensed spectrums. A cell can provide wireless service to a particular geographic area that can be relatively fixed or can change over time. The cell can further be divided into cell sectors. For example, a cell associated with a base station 114a can be divided into three sectors. Thus, in one embodiment, the base station 114a can include three transceivers, one for each sector of the cell. In an embodiment, the base station 114a can employ Multiple-Input Multiple-Output (MIMO) techniques and can utilize multiple transceivers for each sector of the cell. For example, beamforming can be used to transmit and / or receive signals in desired spatial directions.

[0021] The base stations 114a, 114b can communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over the air interface 116, which can 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 can be established using any suitable radio access technology (RAT).

[0022] More specifically, as noted above, the communications system 100 can be a multiple access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a and the WTRUs 102a, 102b, 102c in the RAN 104 / 113 can implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA can include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA can include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0023] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c can implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-A Pro.

[0024] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c can implement a radio technology such as NR Radio Access, which can establish the air interface 116 using New Radio (NR).

[0025] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c can implement multiple radio access technologies. For example, the base station 114a and WTRUs 102a, 102b, 102c can implement LTE wireless access and NR wireless access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c can 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).

[0026] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c can implement radio technologies such as IEEE 802.11 (e.g., Wireless Fidelity (WiFi), IEEE 802.16 (e.g., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 IX, 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.

[0027] Figure 1AThe base station 114b in the embodiment can be, for example, a wireless router, Home Node B, Home eNode B, or access point, and can utilize any suitable RAT for facilitating wireless connectivity access by the WTRUs 102c, 102d within a local area. In one embodiment, the base station 114b and the WTRUs 102c, 102d can 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 can 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 can 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, the base station 114b can have a direct connection to the Internet 110. Thus, the base station 114b can not be required to access the Internet 110 via the CN 106 / 115. Figure 1A

[0028] The RAN 104 / 113 can be in communication with the CN 106 / 115, which can 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 can 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 can 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 Figure 1A Although not shown in FIG. 10, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 can 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 can employ a NR radio technology, the CN 106 / 115 can also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0029] ​The CN 106 / 115 can 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 can include circuit-switched telephone networks that provide infrastructure for the provision of voice telephony, facsimile, and / or other

[0030] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 can include multi-mode capabilities, e.g., the WTRUs 102a, 102b, 102c, 102d can include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRU 102a, 102b, 102c, 102d can include a transceiver Figure 1A The WTRU 102c shown in Figure 1A can be configured to communicate with the base station 114a using a cellular-based radio technology, and can be configured to communicate with the base station 114b using an IEEE 802 radio technology.

[0031] Figure 1B is a system diagram illustrating an example WTRU 102. As shown in Figure 1B The WTRU 102 can 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 can include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0032] The processor 118 can 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 Array (FPGAs), any other type of integrated circuit (IC), a state machine, and the like. The processor 118 can 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 can be coupled to the transceiver 120, which can be coupled to the transmit / receive element 122. While Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, it is to be understood that the processor 118 and the transceiver 120 can be integrated together in an electronic package or chip.

[0033] The transmit / receive element 122 can 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 can be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 can 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 can be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0034] Although the transmit / receive element 122 is depicted in the WTRU 102 Figure 1B In one embodiment, the WTRU 102 can include two or more transmit / receive elements 122 (e.g., multiple antennas) to enable MIMO technology. Thus, the WTRU 102 can

[0035] The transceiver 120 can be configured to modulate information to be transmitted by the transmit / receive element 122 and to demodulate information received by the transmit / receive element 122. As indicated above, the WTRU 102 can be a multi-mode device. Thus, the transceiver 120 can include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0036] The processor 118 of the WTRU 102 can be coupled to, and can 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 can also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 can 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 can include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 can 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 can 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).

[0037] The processor 118 can receive power from the power source 134, and can be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 can be any suitable device for powering the WTRU 102. For example, the power source 134 can 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.

[0038] The processor 118 can also be coupled to the GPS chipset 136, which can 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 can 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 can acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0039] The processor 118 can further be coupled to other peripherals 138, which can 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 can include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands- free headset, a Bluetooth® The peripheral device 138 can include one or more sensors, which can be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, a compass 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.

[0040] The WTRU 102 can include a full duplex radio for which transmission and reception of some or all signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and the downlink (e.g., for reception) can be concurrent and / or simultaneous. The full duplex radio can include an interference management unit 139 to reduce and or substantially eliminate self-interference and / or to reduce interference from other sources. In one embodiment, the WTRU 102 can include a half duplex radio for which transmission and reception of some or all signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception) can be concurrent but not simultaneous.

[0041] Figure 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As described above, the RAN 104 can be in communication with the WTRUs 102a, 102b, 102c over the air interface 116 and can include eNode-Bs 160a, 160b, 160c, although the RAN 104 can include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c can each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNode-Bs 160a, 160b, 160c can implement MIMO technology. Thus, the eNode-B 160a, for example, can use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0042] The RAN 104 can include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 can include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c can each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNode-Bs 160a, 160b, 160c can implement MIMO technology. Thus, the eNode-B 160a, for example, can use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0043] Each of the eNode-Bs 160a, 160b, 160c can be associated with a particular cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, and the like. As shown, the eNode-Bs 160a, 160b, 160c can communicate with one another over an X2 interface. Figure 1C

[0044] Figure 1C The CN 106 can include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements can be owned and / or operated by an entity other than the CN operator.

[0045] The MME 162 can be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via an SI interface and can serve as a control node. For example, the MME 162 can be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activations / deactivations, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 can 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.

[0046] The SGW 164 can be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the SI interface. The SGW 164 can generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 can 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.

[0047] The SGW 164 can be connected to the PGW 166, which can 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.

[0048] ​The CN 106 can facilitate communications with other networks. For example, the CN 106 can 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 landline communications devices. For example, the CN 106 can include, or can 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 can provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which can include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0049] Although WTRUs are described in Figures 1A-1D as being wireless terminals, it is contemplated that in certain representative embodiments such terminals can (e.g., temporarily or permanently) use wired communication interfaces with the communication network.

[0050] In some representative embodiments, the other networks 112 can be a WLAN.

[0051] A WLAN in Infrastructure Basic Service Set (BSS) mode can have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP can 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 is carried by the WLAN can be transmitted from the AP. Traffic from STAs that is carried by the WLAN can be transmitted to the AP. The AP can transmit traffic to the STA(s) and the STA(s) can transmit traffic to the AP in a manner that is compliant with IEEE 802.11e / DL or IEEE 802.11n, or IEEE 802.11ac, or IEEE 802.11ax, or some other IEEE 802.11 protocol. The AP can also be used to transmit and / or receive traffic to and / or from STAs in a peer-to-peer (P2P) arrangement. Traffic between STAs can be transmitted without passing through the AP. The WLAN can use a WLAN radio frequency spectrum that is unlicensed.

[0052] When using an 802.11 ac infrastructure mode of operation or similar mode of operation, an AP can transmit beacons on a fixed channel, such as a primary channel. The primary channel can be a fixed width (e.g., 20 MHz wide bandwidth) or a width that is dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by STAs to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) can be implemented, for example, in 802.11 systems. For CSMA / CA, a STA (e.g., each STA), including the AP, can listen to the primary channel. If the primary channel is sensed / detected as busy by a particular STA, the particular STA can back off. Only one STA can transmit in a given BSS at any given time.

[0053] High Throughput (HT) STAs can use 40 MHz wide channels to communicate, 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.

[0054] Very High Throughput (VHT) STAs can support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. 40 MHz and / or 80 MHz channels can be formed by combining contiguous 20 MHz channels. A 160 MHz channel can be formed by combining 8 contiguous 20 MHz channels, or by combining two noncontiguous 80 MHz channels, which can be referred to as an 80+80 configuration. For the 80+80 configuration, after channel encoding, the data can be parsed by a segment parser that can divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time domain processing can be done on each stream separately. The streams can be mapped to the two 80 MHz channels, and the data can be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration can be reversed, and the combined data can be sent to the Medium Access Control (MAC).

[0055] 802.11af and 802.11ah support sub-1 GHz modes of operation. Channel operating bandwidth and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11η and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the television 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 representative embodiments, 802.11ah can support meter type control / machine type communications, such as MTC devices in a macro coverage area. MTC devices can have certain capabilities, e.g., limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidth. MTC devices can include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0056] WLAN systems that can support multiple channels and channel bandwidths such as 802.11η, 802.11ac, 802.11af, and 802.11ah include a channel that can be designated as a primary channel. The primary channel can have a bandwidth equal to the largest common operating bandwidth supported by all STAs in a BSS. The bandwidth of the primary channel can be set and / or limited by a STA from all STAs operating in the BSS that supports the smallest bandwidth mode of operation. In the example of 802.11ah, for a STA (e.g., MTC type device) that supports (e.g., only supports) a 1 MHz mode, the primary channel can be 1 MHz wide even though other STAs in the AP and BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth modes of operation. Carrier sensing and / or network allocation vector (NAV) settings can depend on the status of the primary channel. If the primary channel is busy, e.g., due to a STA (only supporting a 1 MHz mode of operation) transmitting to the AP, the entire available frequency band can be considered busy even though most of the frequency band remains idle and can be available.

[0057] In the United States, the available frequency band for 802.11ah use is 902 MHz to 928 MHz. In Korea, the available frequency band is 917.5 MHz to 923.5 MHz. In Japan, the available frequency band is 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah use is 6 MHz to 26 MHz, depending on the country code.

[0058] Figure 1D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 can employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 can also be in communication with the CN 115.

[0059] The RAN 113 can include gNBs 180a, 180b, 180c, although it will be appreciated that the RAN 113 can include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c can each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c can implement MIMO technology. For example, gNBs 180a, 108b can utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, can 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 can implement carrier aggregation technology. For example, the gNB 180a can transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers can be on unlicensed spectrum while the remaining component carriers can be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c can implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a can receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0060] The WTRUs 102a, 102b, 102c can use OFDM symbols of different lengths associated with different numerologies to communicate with the gNBs 180a, 180b, 180c. For example, the OFDM symbol spacing and / or the OFDM subcarrier spacing can vary from different transmissions, from different cells, and / or from different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c can use subframes or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing different numbers of OFDM symbols and / or lasting varying lengths of absolute time) to communicate with gNBs 180a, 180b, 180c.

[0061] The gNBs 180a, 180b, 180c can be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, the WTRUs 102a, 102b, 102c can communicate with one or more of gNBs 180a, 180b, 180c without also accessing other RANs, such as eNode-Bs 160a, 160b, 160c. In the standalone configuration, the WTRUs 102a, 102b, 102c can utilize WTRU 102a, 102b, 102c for mobility, in which case the gNBs 180a, 180b, 180c can function as the WTRUs’ 102a, 102b, 102c mobility anchor points. In the standalone configuration, the WTRUs 102a, 102b, 102c can use signals

[0062] Each of the gNBs 180a, 180b, 180c can be associated with a specific cell (not shown) and can 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 functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, and / or the like. As shown, the gNBs 180a, 180b, 180c can communicate with one another over an Xn interface. Figure 1D As shown, the gNBs 180a, 180b, 180c can be in communication with the core network 180, which can be in communication with additional networks, such as the Internet. As shown, the core network 180 can include a 5G core network, which can include one or more AMFs 182a, 182b, one or more UPFs 184a, 184b, and / or the like. The AMFs 182a, 182b can manage non-access stratum (NAS) functions such as mobility, authentication, and access authorization; inter-core network signaling for mobility between 5G core networks; and / or the like. The UPFs 184a, 184b can provide packet routing, forwarding, packet inspection, quality of service (QoS) handling, and / or the like. The UPFs 184a, 184b can be connected to the 5G core network and can provide an interface for routing traffic between the UEs and the core network.

[0063] Figure 1DThe illustrated CN 115 can 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 can be owned and / or operated by an entity other than the CN operator.

[0064] The AMF 182a, 182b can be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and can serve as a control node. For example, the AMF 182a, 182b can be responsible for authenticating the WTRUs 102a, 102b, 102c, supporting for different PDU sessions with different requirements, selecting a particular SMF 183a, 183b, management of the WTRU 102a, 102b, 102c registration area, termination of NAS signaling, mobility management, and the like. The AMF 182a, 182b can utilize network slicing to customize CN support for the WTRUs 102a, 102b, 102c based on the type of services being utilized, e.g., the difference services to which different PDU sessions have been assigned. For example, different network slices can be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. The AMF 182 can provide control plane functionality for 5G NR access, other radio access technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi. The AMF 182 can also serve as a control plane anchor for the WTRUs 102a, 102b, 102c when they enter an unconnected state, e.g., EMM-Committed or ECM-Inactive.

[0065] The SMF 183a, 183b can be connected to AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b can also be connected to the UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b can select and control the UPF 184a, 184b and configure the routes for traffic through the UPF 184a, 184b. The SMF 183a, 183b can perform other functions, such as managing and allocating IP address

[0066] The UPF 184a, 184b can be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which can provide 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 can perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering of downlink packets, providing mobility anchoring, and the like.

[0067] The CN 115 can facilitate communications with other networks. For example, the CN 115 can include, or can 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. Further, the CN 115 can provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which can include other wired and / or wireless networks that are owned and / or operated by other service providers. In embodiments, the WTRUs 102a, 102b, 102c can be connected to a DN 185a, 185b through the UPF 184a, 184b via the N3 interface between the UPF 184a, 184b and the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0068] In view of Figures 1A-1D And Figures 1A-1D In view of the corresponding descriptions of FIGS. 1 through 18, one or more or all of the functions described with reference to one or more of the WTRUs 102a-102d, base stations 114a-114b, RAN nodes 180a-180b, core network elements 152, 160, 162, 164, 166, 182a- 182b, 183a-183b, 184a-184b, 185a-185b, and / or any other devices taught herein can be performed by one or more emulation devices (not shown). The emulation device can be configured to emulate one or more— or all— of the functions described herein. For example, an emulation device can be used to test other devices and / or to emulate a network and / or WTRU behavior.

[0069] The one or more emulation devices can perform one or more, including all, functions while not implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices can be utilized in testing scenarios 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 can be test equipment. Direct RF coupling and / or wireless communications, via RF circuitry (e.g., which can include one or more antennas), can be used by the emulation devices to transmit and / or receive data.

[0070] The one or more emulation devices can perform one or more, including all, functions while not implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices can be utilized in testing scenarios 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 can be test equipment. Direct RF coupling and / or wireless communications, via RF circuitry (e.g., which can include one or more antennas), can be used by the emulation devices to transmit and / or receive data.

[0071] Embodiments disclosed herein generally relate to wireless and / or wired communication networks. For example, one or more embodiments disclosed herein relate to methods and apparatuses for uplink control enhancements (e.g., overhead reduction) in wireless communications.

[0072] New radio (NR) technology can support and / or provide one or more services to one or more WTRUs. Such services can be of varying and / or different latency and reliability requirements. Examples of services that NR technology can support include URLLC and / or eMBB services. To better support operations with different types of services (such as URLLC and eMBB), mechanisms for enabling low latency reception have been introduced to enable low latency reception and / or high reliability transmission. The reliability, accuracy, and timeliness of feedback reports (e.g., CQI and HARQ-ACK) can be needed to meet the varying and / or different latency and reliability requirements of various services.

[0073] NR supports one or multiple flexible transmission durations within a slot. NR supports semi-static resources for data transmission in uplink (UL) and / or downlink (DL) directions. Configured grant (CG) Type 1 and Configured grant (CG) Type 2 can be used for uplink transmissions. For CG Type 1, the network can semi-statically configure uplink grants and the WTRU can autonomously use the uplink grants without L1 indication / activation. Configured grant (CG) Type 2 is similar to CG Type 1 but requires L1 activation so that the WTRU can use the configured grant to start uplink transmissions. NR supports DL semi-persistent scheduling (SPS) resources (or DL configured grant (CG)), including resources on which the WTRU can receive DL data for active DL CGs without scheduling for each DL transport block (TB).

[0074] NR supports UL and DL services with different QoS requirements within a single WTRU, with different delay and reliability requirements for traffic. NR supports time- sensitive communications and networking, including deterministic and non-deterministic time- sensitive networking (TSN) traffic patterns and flows, and these patterns and flows can be prevalent in factory automation settings using licensed and / or unlicensed spectrum.

[0075] In various embodiments, channel state information (CSI) can include one or more of the following: channel quality index (CQI), rank indicator (RI), precoding matrix index (PMI), layer 1 (L1 or PHY layer) channel measurements (e.g., reference signal received power (RSRP) such as L1-RSRP, or signal to interference plus noise ratio (SINR)), CSI-RS resource indicator (CRI), synchronization signal (SS) / physical broadcast channel (PBCH) block resource indicator (SSBRI), layer indicator (LI), and / or any other measurement quantity measured by a WTRU that configures a CSI-RS and / or SS / PBCH block.

[0076] In various embodiments, UL control information (UCI) can include one or more of the following: CSI, hybrid automatic repeat request (HARQ) feedback for one or more HARQ processes, scheduling request (SR), link recovery request (LRR), CG-UCI, and / or other control information bits that can be transmitted on a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH).

[0077] In various embodiments, the channel condition can be or can include any condition related to the status of a radio or channel, and the channel condition can be determined by the WTRU from one or more of: WTRU (or UE) measurements (e.g., L1 / SINR / RSRP, CQI / modulation and coding scheme (MCS), channel occupancy, received signal strength indicator (RSSI), power headroom, or energy exposure headroom), L3 / mobility-based measurements (e.g., RSRP, reference signal received quality (RSRQ)), radio link monitoring (RLM) status, and / or channel availability of unlicensed spectrum. Channel availability can include determining whether a channel is occupied based on determining a listen-before-talk (LBT) procedure, or whether a channel is deemed to have experienced consistent LBT failures.

[0078] There can be multiple active CG / SPS, multiple time sensitive communication (TSC) traffic patterns, and / or shorter (e.g., symbol level) SPS periods, and there can be a large number of HARQ feedback bits to report simultaneously when the DL part is longer than the UL part, especially in time division duplex (TDD) mode. In some cases, the WTRU can not be able to report all HARQ feedback bits (e.g., one or more pending HARQ feedback bits) in the first possible UL slot or sub-slot. Some of the HARQ processes for which the WTRU needs to report feedback can have lower priority or be bound to less stringent delay requirements services. Therefore, uplink control enhancements, such as feedback overhead reduction, can be desirable.

[0079] Representative procedures for feedback overhead reduction

[0080] In the case of multiple active DL SPS, reporting UCI (e.g., ACK / NACK feedback) for all active configurations would increase the uplink overhead. For TDD operation mode, the amount of resources reserved for uplink transmission can not be able to support the high overhead of HARQ-ACK feedback. For example, an IoT device or WTRU operating in TDD mode can be configured with multiple active DL SPS for which HARQ-ACK feedback should be reported. In various embodiments, feedback overhead reduction procedures / mechanisms can be applied for HARQ-ACK feedback of DL SPS transmissions and / or dynamically scheduled TBs.

[0081] Representative triggering events for feedback overhead reduction mechanisms

[0082] In various embodiments, the WTRU can apply feedback overhead reduction (other terms can be used or interchanged, such as UCI payload reduction, UCI overhead reduction, feedback reduction, feedback overhead reduction, or feedback overhead reduction) mechanisms based on any of the following:

[0083] • Either of a HARQ-ACK codebook and UCI payload that meets a threshold. The WTRU can be (statically, semi-statically, and / or dynamically) configured with a threshold payload N th If the HARQ-ACK codebook meets (e.g., is greater than or equal to) the threshold, the WTRU can apply the feedback overhead reduction mechanism.

[0084] • A number of activated DL SPS or DL SPS configurations is above a preconfigured threshold. For example, once the WTRU is activated with a number of DL SPSs that is above a preconfigured threshold, the WTRU can apply the feedback overhead reduction mechanism.

[0085] • A received TDD configuration. In various embodiments, if the WTRU receives a TDD configuration (e.g., either of a semi-static configuration and a dynamic configuration), and a number of uplink slots within a time window (e.g., within a TDD-DL-UL transmission period) is below a preconfigured threshold, the WTRU can apply the feedback overhead reduction mechanism. In various embodiments, the WTRU can be configured with a set of slot format indications (SFIs) that can trigger one or more feedback overhead reduction mechanisms. Upon the WTRU receiving a group common DCI (i.e., a DCI intended for a group of WTRUs or all WTRUs) indicating one of the preconfigured SFIs in the set, the WTRU can apply one or more of the feedback overhead reduction mechanisms.

[0086] • An allocated resource of a PUCCH for HARQ-ACK codebook or UCI transmission. In various embodiments, a payload of a PUCCH resource indicated for one or more HARQ-ACK transmission can trigger one or more feedback overhead reduction mechanisms. If a payload of an allocated PUCCH resource is below a preconfigured threshold, the WTRU can apply one or more of the feedback overhead reduction mechanisms.

[0087] • An allocated resource of a PUSCH for UCI or HARQ-ACK codebook. In various embodiments, a payload (e.g., a beta factor) of a resource indicated for one or more HARQ-ACK transmission within a PUSCH can trigger one or more feedback overhead reduction mechanisms.

[0088] • One or more explicit indications from the network (e.g., gNB). In various embodiments, the WTRU can receive a DCI indicating and / or activating one or more feedback overhead reduction mechanisms. The received DCI can schedule a DL transmission, provide an UL grant, and / or be used to activate a DL SPS / configured UL grant transmission. In various embodiments, the DCI can include any of an implicit and explicit indication indicating and / or activating one or more of the feedback overhead reduction mechanisms. The explicit indication can be, for example, one or more values specifically set in one or more bit fields of the DCI or encoded onto one or more bit fields of the DCI.

[0089] • Active bandwidth part (BWP). In embodiments, the WTRU can apply one or more feedback overhead reduction mechanisms if a default BWP is activated. The set of BWPs for which the WTRU can apply feedback overhead reduction can be configured using RRC signaling (e.g., as part of the BWP configuration). The set of BWPs can also be configured using broadcast or other signaling. The BWP configuration can enable the network to reduce overhead on small BWPs. In various embodiments, the WTRU can apply one or more feedback overhead reduction mechanisms if the WTRU receives either a BWP switch command or a PDSCH associated with a BWP different from the active BWP.

[0090] • Component carrier (CC) on which the WTRU can report HARQ-ACK feedback. In various embodiments, the WTRU can apply feedback overhead reduction mechanisms on one or more licensed carriers and / or deactivate feedback overhead reduction mechanisms on one or more unlicensed carriers. In various embodiments, the WTRU can apply feedback overhead reduction mechanisms on one or more unlicensed carriers and / or deactivate feedback overhead reduction mechanisms on one or more licensed carriers.

[0091] • Channel conditions or measurements. In embodiments, the WTRU can enable and / or deactivate one or more feedback overhead reduction mechanisms based on any of CSI, BLER, power headroom, exposure headroom, and RSRP measurements. The WTRU can measure channel conditions (e.g., with low SINR) and thus enable feedback overhead reduction mechanisms (e.g., based on the measured channel conditions). In various embodiments, the WTRU can apply one or more feedback overhead reduction mechanisms if channel conditions remain the same (or satisfy a given set of channel conditions) during a time period (e.g., a time window). The time period can be configured statically, semi-statically, and / or dynamically.

[0092] • At least one PDSCH (e.g., one HARQ-ACK bit) satisfies any of the feedback reduction criteria detailed in the next section.

[0093] • For example, when the WTRU is performing L3 measurements, when the feedback reporting occasion overlaps with a measurement gap, or when the WTRU has one or more ongoing beam failure recovery or beam refinement procedures, the WTRU can have an ongoing L2 or L3 procedure.

[0094] UCI payload reduction

[0095] In various embodiments, the WTRU can apply one or more feedback overhead reduction mechanisms to reduce the feedback overhead. The feedback overhead reduction mechanisms can include any one of UCI compression, UCI skipping, UCI splitting, and UCI delaying. In various embodiments, the UCI compression can include HARQ-ACK codebook compression, the UCI skipping can include HARQ-ACK bit feedback skipping, and the UCI delaying can include HARQ-ACK feedback delaying.

[0096] UCI compression / bundling

[0097] In various embodiments, the WTRU can apply HARQ-ACK codebook compression. In various embodiments, the HARQ-ACK codebook compression can be performed using a compression function on a HARQ-ACK codebook having a size of N bits. In various embodiments, the compression function can include a logical AND operation on all or a subset of one or more ACK / NACK bits belonging to the HARQ-ACK codebook. In various embodiments, the WTRU can be configured to perform a logical AND operation on only a subset of ACK / NACK bits of the HARQ-ACK codebook. For example, the WTRU can perform a logical AND operation on the n1 most significant bits (n1 < N) of the HARQ-ACK codebook and can transmit 1 bit (or a number of bits less than n1 bits) instead of n1 bits. This mechanism can be beneficial if only detailed ACK / NACK feedback is needed for the last set of transmitted PDSCHs (e.g., the last PDSCH or PDSCHs transmitted from the network). For example, the channel conditions during the first set of PDSCH transmissions (e.g., the first PDSCH or PDSCHs transmitted from the network) can be similar, and thus only detailed ACK / NACK feedback is needed for the last set of transmitted PDSCHs.

[0098] In various embodiments, the WTRU can compute an AND (logical AND) operation of the n1 last (or lowest) significant bits (n1 < N) of the HARQ-ACK codebook and can transmit 1 bit (or multiple bits less than n1 bits) instead of n1 bits. This mechanism can be beneficial if only detailed ACK / NACK feedback for the first set of transmitted PDSCHs (e.g., the first PDSCH or PDSCHs transmitted from the network) is needed. For example, the channel conditions during the last set of PDSCH transmissions (e.g., the last PDSCH or PDSCHs transmitted from the network) can be similar, thus only detailed ACK / NACK feedback for the first set of transmitted PDSCHs is needed.

[0099] In various embodiments, the WTRU can compute an AND (logical AND) operation of each n1 sequence of N bits. The WTRU can compute bits as the HARQ-ACK codebook report. In various embodiments, the WTRU can report an AND (logical AND) operation of all ACK / NACK bits of the HARQ-ACK codebook. The number n1 can be semi-statically configured from the network or dynamically determined based on the number N of HARQ-ACK codebook to be reduced (e.g., the number of HARQ bits to be reduced). In various embodiments, the number n1 can be a fraction of N (e.g., n1 = a*N) and N can be dynamically changed, thus n1 can also be dynamically changed.

[0100] In various embodiments, the WTRU can bundle the HARQ feedback for multiple TBs, for example, based on any of the associated DL resource group and assignment time. For example, the WTRU can generate a single feedback bit for each PDSCH or TB group / group belonging to the same bundle. The WTRU can generate an ACK if all TBs in the bundle have been successfully decoded or a NACK if at least one TB in the bundle has not been successfully decoded. In various embodiments, the TB group or group or PDSCH bundle can be determined by one or more of the following:

[0101] • Configuration of coupled resources. For example, RRC signaling can be used to configure the WTRU with multiple PDSCH resources (e.g., DL SPS resources) to map to a single PDSCH group.

[0102] • Configuration of coupled HARQ processes. For example, RRC signaling can be used to configure the WTRU with multiple DL HARQ process IDs to map to a single PDSCH group.

[0103] • Assign time. The WTRU can bundle HARQ feedback for all TBs received within the current, past, or last x slots or sub-slots; where x is predefined or preconfigured. The WTRU can bundle HARQ feedback for all TBs that overlap in time domain and / or frequency domain. The WTRU can bundle HARQ feedback for all TBs scheduled simultaneously (e.g., by the same or different DCI in the same instance).

[0104] UCI skipping

[0105] In one embodiment, a WTRU can be configured to apply UCI or HARQ-ACK feedback skipping. In an example, the WTRU can skip (e.g., not report) ACK / NACK bits for some (e.g., one or more) of the scheduled PDSCHs. For example, the WTRU can not transmit a subset of ACK / NACK bits of a HARQ-ACK codebook corresponding to one or more HARQ processes of a low priority transmission or retransmission.

[0106] UCI deferral

[0107] In one embodiment, a WTRU can be configured to apply UCI or HARQ-ACK feedback delay. In an example, the WTRU can postpone transmission of ACK / NACK bits for a scheduled PDSCH. The WTRU can postpone transmission of HARQ-ACK feedback for a subset of HARQ processes and, for example, transmit the HARQ-ACK feedback in a different slot, sub-slot, and / or different PUCCH resource indication (PRI).

[0108] UCI splitting / splitting

[0109] Reference Figure 2 In one embodiment, a WTRU can be configured to split a HARQ-ACK codebook into multiple sub-codebooks, where some sub-codebooks can not be transmitted, or can be delayed or skipped. The WTRU can determine a HARQ-ACK codebook size for a given UCI transmission based on at least one of:

[0110] • The number of available UCI payloads for transmission (or transmission at a certain reliability level) on the PUCCH.

[0111] • The number of HARQ processes for which the WTRU is providing feedback. In an example, the number of HARQ processes can exclude any HARQ processes for which the WTRU applies feedback reduction.

[0112] • The number of bits available for UCI transmission on a given PUSCH resource.

[0113] • Legacy inputs (e.g., downlink assignment index (DAI) counter, PDSCH group index, or number of HARQ processes, etc.).

[0114] Selection of HARQ-ACK bits for feedback overhead reduction

[0115] In various embodiments, the WTRU can be configured to select one or more HARQ-ACK bits for which UCI payload reduction can be applied. In an example, the WTRU can have received N PDSCHs to be reported within the same HARQ-ACK codebook. Based on one or more of the above-mentioned triggering events, the WTRU can enable UCI payload or HARQ feedback reduction. For example, the WTRU can be configured to apply feedback reduction if at least one PDSCH (e.g., one HARQ-ACK bit) meets any one of the following feedback reduction criteria. In an example, the group of PDSCHs for which feedback is skipped, delayed, or split / compressed can be selected based on one or more of the following:

[0116] • Priority associated with the HARQ-ACK or associated PDSCH transmission. The WTRU can select a group of ACK / NACK bits for which feedback overhead reduction can be applied based on the priority of the HARQ-ACK or associated PDSCH transmission and / or codebook index. For example, once the feedback reduction mechanism is enabled, the WTRU can be configured to apply feedback reduction (e.g., skip or delay transmitting ACK / NACK bits) for low priority data. The WTRU can determine the priority of a PDSCH according to the priority level or index associated with the PDSCH (e.g., for resource indication or configuration), PDSCH resources, characteristics of the scheduling DCI (e.g., priority index signaled in the DCI and / or coreset used for scheduling).

[0117] • Applicable HARQ-ACK slot / sub-slot configuration (e.g., when the HARQ-ACK codebook is based on sub-slot).

[0118] • Whether a PDSCH is transmitted for DL SPS. For example, the WTRU can be configured to determine whether a PDSCH transmission for an activated DL SPS configuration is received. If no PDSCH is received, the WTRU can skip transmitting ACK / NACK feedback for that transmission. The WTRU can be configured to determine the presence and / or transmission of SPS PDSCH based on the following:

[0119] i) DMRS detection. For example, DMRS energy is less than a preconfigured threshold; and / or

[0120] ii) Energy detected on the allocated PDSCH symbols is less than a preconfigured threshold.

[0121] • The periodicity of the DL SPS configuration. For example, the WTRU can be configured to delay transmission of ACK / NACK feedback bits corresponding to a DL SPS configuration with a high periodicity. In this case, the WTRU can have an additional opportunity indicated by the network in a subsequent slot.

[0122] • Whether the PDSCH carries a HARQ retransmission. For example, once feedback overhead reduction is enabled, the WTRU can be configured to skip or delay transmission of ACK / NACK feedback bits for retransmission (or new transmission).

[0123] • The HARQ process associated with the PDSCH. For example, the WTRU can be configured by RRC signaling with a subset of HARQ processes for which the WTRU can apply feedback reduction.

[0124] • Whether the PDSCH is scheduled on a newly activated BWP and / or carrier or a previously active BWP / carrier. In an example, the WTRU can be configured to apply feedback reduction for HARQ-ACK bits associated with a newly activated BWP / carrier. In another example, the WTRU can be configured to apply feedback reduction for HARQ-ACK bits associated with the last active BWP.

[0125] • The MCS of the PDSCH. For example, the WTRU can be configured to apply feedback overhead reduction for HARQ processes associated with PDSCHs scheduled with a specific MCS, MCS range, and / or MCS table. The association can be configured by RRC signaling or predetermined. In some examples, each MCS, MCS range, or MCS table can be associated with a respective priority, service type, reliability level, and / or reliability requirement.

[0126] • The transport block size (TBS) of the PDSCH. For example, the WTRU can be configured to apply feedback reduction for HARQ processes associated with PDSCHs if the TBS is greater than (or less than) a preconfigured threshold.

[0127] • Whether the PDSCH is associated with a random access procedure (e.g., the small data transmission part of MsgB).

[0128] • The radio network identifier (RNTI) associated with the PDSCH or used to schedule the PDSCH. For example, the WTRU can be configured to apply feedback reduction for PDSCHs associated with a subset of C-RNTIs or CS-RNTIs.

[0129] • The transmission configuration indicator (TCI) state used for the PDSCH;

[0130] • Antenna port group for PDSCH;

[0131] • Demodulation reference signal (DM-RS or DMRS) mapping type for PDSCH. In an example, a WTRU can be configured to determine and / or use at least one of two or more DM-RS mapping types. The WTRU can select the HARQ ACK / NACK feedback to be delayed / skipped if the respective PDSCH assignment for HARQ feedback has a similar DM-RS mapping type.

[0132] • Whether the PDSCH is related to transmission of a multicast service and / or a multicast channel. For example, for a hybrid mode WTRU, the WTRU can be configured to apply feedback reduction for transport channels and / or PDSCHs associated with multicast or broadcast services, physical channels, and / or resources.

[0133] • PDSCH to HARQ-ACK (K1) value. For example, if the value of K1 satisfies a certain threshold (e.g., greater or less than a certain threshold) or is non-numeric, the WTRU can be configured to apply feedback reduction.

[0134] • Time period since initial transmission or start of self-TB transmission / retransmission (e.g., time since start or end of PDSCH containing initial TB transmission or retransmission). In various embodiments, the WTRU can be configured to apply feedback reduction if the time period (e.g., since initial transmission or start of TB transmission) is below a preconfigured threshold. In various embodiments, the WTRU can be configured to apply feedback reduction for TBs transmitted in the same channel occupancy time (COT) when there are unsent TBs from a previous COT.

[0135] • Whether the PDSCH is transmitted on DL SPS resources associated with UL CGs or on dedicated resources for HARQ feedback. For example, the WTRU can be configured with one or more associations between one or more DL SPS resources and one or more UL CGs. The WTRU can be configured to apply feedback reduction for DL TBs received on such DL SPS resources configured with such associations.

[0136] In various embodiments, a WTRU can be configured to transmit HARQ-ACK feedback corresponding to a set of PDSCHs depending (at least) on whether the WTRU performs a transmission of other UCI or data in the same slot or sub-slot. For example, if a HARQ-ACK corresponding to at least one PDSCH scheduled by DCI is transmitted in the same slot or sub-slot, or if the WTRU transmits a PUSCH, CSI, Sounding Reference Signal (SRS), or Scheduling Request (SR) in the same slot or sub-slot, or if at least one HARQ-ACK has a certain value such as NACK (or ACK), a HARQ-ACK corresponding to a single or set of SPS PDSCHs or PDSCHs without DCI can be transmitted in the slot or sub-slot. Doing so can avoid excessive overhead and interference from PUCCH when the periodicity of SPS is very low and no other transmission is made.

[0137] In various embodiments, a WTRU can be configured to transmit HARQ-ACK on PUCCH in a slot or sub-slot if at least one of the following conditions is met, otherwise it can not transmit in that slot or sub-slot:

[0138] • At least one HARQ-ACK is a certain value, such as ACK (or NACK);

[0139] • The type of HARQ codebook is one of a set of types, such as Type 1 or Type 2;

[0140] • The priority indication associated with the HARQ-ACK is a certain value;

[0141] • The applicable HARQ-ACK slot / sub-slot configuration (e.g. when the HARQ-ACK codebook is based on sub-slot);

[0142] • Whether the UL (or DL) bandwidth part is switched since PDSCH transmission;

[0143] • Within the same HARQ-ACK codebook in the same slot or sub-slot:

[0144] i) At least one HARQ-ACK bit is for PDSCH reception scheduled by DCI;

[0145] ii) At least one HARQ-ACK bit is for SPS PDSCH release; and / or

[0146] iii) At least one HARQ-ACK bit is related to PDSCH with a particular value of a characteristic, where the characteristic can be one listed in the previous paragraph (e.g., MCS, MCS range, MCS table, PRB number, TB size, TCI state, antenna port, RNTI, multicast service, DMRS mapping type, etc.).

[0147] • Within the same slot or sub-slot:

[0148] i) The WTRU transmits (e.g., data or CSI) on PUSCH; and / or

[0149] ii) The WTRU transmits CSI, SRS, or SR (e.g., on PUCCH or PUSCH);

[0150] Determining skipped SPS PDSCH transmissions

[0151] In various embodiments, a WTRU can be configured with one or more SPS PDSCH configurations. The WTRU can receive an SPS PDSCH activation command and can expect a PDSCH transmission in the resources of the SPS PDSCH. In some cases, there can be no PDSCH transmission in the activated SPS PDSCH resources. Thus, it can be beneficial for the WTRU to identify resources in which to skip SPS PDSCH transmission.

[0152] The WTRU can determine whether an SPS PDSCH resource is for transmission. The determination can be performed by at least one of:

[0153] • Reception of an RS. For example, if the WTRU detects or decodes an RS (e.g., DM-RS) that can be associated with a transmission, the WTRU can assume that the SPS PDSCH is transmitted;

[0154] • Reception of a signal or channel. For example, if the WTRU detects a signal to be transmitted in conjunction with the SPS PDSCH transmission, the WTRU can assume that the SPS PDSCH is transmitted. Such a signal can be multiplexed with the SPS PDSCH or can be received in an orthogonal set of resources. In another example, reception of the signal can indicate to the WTRU that there is no SPS PDSCH in the associated SPS PDSCH transmission occasion;

[0155] • Reception of the SPS PDSCH or a portion thereof. For example, the WTRU can determine the presence of the SPS PDSCH based on receiving at least a portion of the SPS PDSCH. In an example, the WTRU can detect some or all of the transmitted code blocks (or code block groups or transport blocks). The WTRU can determine that the SPS PDSCH is transmitted independent of the outcome of a decoding procedure; and / or

[0156] • implementation of a threshold measurement. For example, the WTRU can perform a measurement (e.g., SINR) on a set of resources associated with a SPS PDSCH transmission occasion. If the measurement result is above (or below) a threshold, the WTRU can determine the presence or lack of SPS PDSCH transmission.

[0157] In one embodiment, the WTRU can receive an indication confirming whether a previous SPS PDSCH transmission occasion was used for transmission of SPS PDSCH. The WTRU can receive a DAI-like signal in each SPS PDSCH. The DAI can cycle through values, and based on the value obtained in the SPS PDSCH, the WTRU can determine whether a previous SPS PDSCH transmission was skipped. This can enable the WTRU to distinguish between a skipped SPS PDSCH transmission and an erroneously detected SPS PDSCH transmission. In an example, the WTRU can expect the DAI to only increment for each actually transmitted SPS PDSCH. For any group of received SPS PDSCH transmissions, the WTRU can determine whether one or more SPS PDSCH transmissions were missed based on the order of the received DAI values. In some cases, the DAI can be received as part of the SPS PDSCH transmission, or can be received in another signal in the resources associated with the SPS PDSCH transmission. The WTRU can determine whether to skip a SPS PDSCH transmission or determine the DAI of a SPS PDSCH transmission based on at least one of:

[0158] • an explicit indication in the SPS PDSCH transmission. For example, the DAI can be received in a subset of resources (e.g., configurable subset) for the SPS PDSCH transmission and included in a DCI format (e.g., DCI format with small / less payload);

[0159] • an indication included in the SPS PDSCH TB. For example, the WTRU can receive the DAI (and / or indication) in a set of resources multiplexed with the TB. The DAI can be encoded separately from the rest of the TB;

[0160] • an indication through a cyclic redundancy check (CRC). For example, the DAI value can be used to compute the CRC. The WTRU can attempt to decode the TB using each of the possible DAI values, and determine the appropriate DAI value when the CRC decoding is successful; and / or

[0161] • One or more DM-RS parameters. For example, the parameters of the DM-RS can be determined based on (or as a function of) the DAI value. The parameters can include any of the following: RS sequence, DM-RS resource, orthogonal cover code (OCC), and / or the like.

[0162] In one embodiment, the WTRU can receive an indication (e.g., in a SPS PDSCH) of a number of previously skipped SPS PDSCH transmissions. In some examples, the indication can be configured to use / apply any of the procedures for DAI reception discussed herein.

[0163] In one embodiment, the WTRU can receive an indication or value in the last SPS PDSCH transmission indicating the total number of skipped and / or non-skipped SPS PDSCH transmissions (e.g., SPS PDSCH transmission occasions for transmitting PDSCH) in a group of SPS PDSCH transmission occasions. The group of SPS PDSCH transmission occasions can include all occasions for which the WTRU is expected to report feedback in the same resources. In an example, the indication can be received in the resources of the last non-skipped SPS PDSCH transmission. In another example, the indication can be expected to be received in a predetermined SPS PDSCH transmission occasion. In this case, the WTRU can receive the indication in the predetermined (e.g., last) SPS PDSCH transmission occasion indicating a set of skipped and / or non-skipped SPS PDSCH transmissions (or the total number thereof) in a group of SPS PDSCH transmission occasions. The WTRU can receive the indication in the predetermined SPS PDSCH transmission occasion regardless of whether the SPS PDSCH transmission occasion itself for transmitting the SPS PDSCH is skipped (or non-skipped).

[0164] HARQ-ACK feedback when one or more SPS PDSCH configurations are activated

[0165] In various embodiments, the WTRU can receive activation of one or more SPS PDSCH configurations, but not all SPS PDSCH transmission occasions can be used for transmission of SPS PDSCH (e.g., skipped SPS PDSCH). The WTRU can determine the content of HARQ-ACK feedback associated with such SPS PDSCH depending on whether there are any skipped SPS PDSCH transmissions.

[0166] In one embodiment, the WTRU can determine whether to report HARQ-ACK feedback for one or more (skipped or non-skipped) SPS PDSCH transmission occasions (or HARQ processes) based on (e.g., as a function of) at least one of the following:

[0167] • Priority of the transmission. For example, for high priority SPS PDSCH configurations, the WTRU can always include HARQ-ACK feedback for all SPS PDSCH transmission occasions (e.g., regardless of whether they are skipped or not). In another example, the WTRU can determine whether to report HARQ-ACK for all transmission occasions or not, or only for unskipped transmission occasions, or only for ACK or only for NACK SPS PDSCH TBs depending on the priority level of the SPS PDSCH. In another example, the determination can depend on the priority of the SPS PDSCH transmission and can also depend on the priority of other transmissions for which the WTRU can have to feedback HARQ-ACK in the same feedback resource. For example, if the WTRU is configured to report feedback for SPS PDSCH transmissions and dynamic grant (DG) PDSCHs in a single feedback report, the WTRU can determine whether to report feedback for SPS PDSCH or DG PDSCH depending on the priority of either of the SPS PDSCH and / or DG PDSCH.

[0168] • Reported HARQ status. For example, the WTRU can report HARQ-ACK for SPS PDSCH TBs that meet a certain HARQ status (e.g., ACK, NACK, or skipped). In an example, the WTRU can skip the entire report if all SPS PDSCHs are found to be skipped or NACK or ACK or a combination thereof. In an example, the WTRU can report HARQ-ACK for only SPS PDSCH TBs that are skipped or NACK. In such an example, the WTRU can explicitly indicate the set of SPS PDSCH TBs (or HARQ process IDs) for which the WTRU determines to be skipped or NACK. In another example, the WTRU can distinguish between the set of HARQ processes for which the WTRU determines SPS PDSCH to be skipped and the set of processes for which the WTRU determines to be NACK. In yet another example, the WTRU can report the presence of a minimum number of elements of a group of SPS PDSCH HARQ processes (for skipped SPS PDSCH, for ACK, for NACK, or any combination thereof). For example, if the WTRU determines that there is one skip and four ACKs in a group of five SPS PDSCH occasions, the WTRU can report the HARQ process ID of the skipped SPS PDSCH occasion. In some cases, the WTRU can bundle skipped SPS PDSCH transmissions and / or NACKs in a group.

[0169] • The PDSCH type for which feedback is included in the report. For example, the WTRU can determine whether the report includes feedback for SPS PDSCH, DG PDSCH, or a combination thereof. For example, the WTRU can determine a group of SPS PDSCH HARQ processes for which the WTRU can report HARQ-ACK feedback based on whether a HARQ-ACK report for a DG PDSCH HARQ process is included in the report. For example, if the HARQ-ACK report contains only a report for SPS PDSCH HARQ processes, the WTRU can (e.g., can only) discard the entire HARQ-ACK report. The determination can also depend on whether the reporting resource is configured to report for one or more SPS PDSCH configurations; and / or

[0170] • Based on a counter obtained from the network (e.g., gNB). As described herein, the WTRU can receive an indication (e.g., from the gNB) indicating a total number of SPS PDSCH transmissions in a group of SPS PDSCH transmission occasions that were not skipped. The WTRU can determine a group of HARQ processes for which to provide HARQ-ACK feedback based on the indicated counter value. For example, if the counter value matches the WTRU’s understanding of the total number of SPS PDSCH transmissions that were not skipped, the WTRU can report HARQ-ACK for the SPS PSCH HARQ processes that were not skipped, or can determine whether to transmit or completely discard the HARQ-ACK feedback based on one or more methods / procedures described herein. In another example, if the counter value does not match the WTRU’s understanding of the total number of SPS PDSCH transmissions that were not skipped, the WTRU can report HARQ-ACK feedback for all SPS PDSCH HARQ processes (e.g., using NACK for SPS PDSCH transmissions that were considered skipped). In some cases, the WTRU can receive an indication that all SPS PDSCH transmissions in the group were skipped. In this case, the WTRU can transmit ACK for the indication, or can completely skip the feedback report.

[0171] Indication of HARQ-ACK codebook size

[0172] In various embodiments, the WTRU can report / feedback all HARQ-ACK feedback or a subset of HARQ-ACK feedback for SPS or DG PDSCH transmissions or not report / feedback HARQ-ACK feedback. In some cases, this can result in different HARQ-ACK codebook sizes. To ensure that the WTRU and the network (e.g., gNB) have a common understanding of the HARQ-ACK codebook size, the WTRU can receive an indication of the expected codebook size (e.g., from the gNB) prior to the feedback report.

[0173] In an embodiment, a WTRU can determine a HARQ process group to give feedback (e.g., per the rules described herein). The WTRU can determine the size and content of a HARQ-ACK codebook and can indicate the determined information (e.g., size and / or content) to the gNB. For example, the HARQ-ACK feedback can include a set of bits (e.g., NACK or ACK or skipped PDSCH or SPS PDSCH or DG PDSCH, or any combination thereof) that indicate the size of the codebook or the content of the codebook.

[0174] In an embodiment, a WTRU can determine the number of non-skipped SPS PDSCH transmissions. If the WTRU confirms that its determination of the number of non-skipped SPS PDSCH is correct (e.g., via signaling from the gNB), the WTRU can use a dynamic codebook (e.g., including feedback for all possible SPS PDSCH HARQ process subgroups). If the WTRU confirms that its determination of the number of non-skipped SPS PDSCH transmissions is incorrect, the WTRU can use a semi-static codebook.

[0175] Representative procedures for HARQ-ACK codebook compression

[0176] Selective transmission of codebook segments

[0177] In various embodiments, a WTRU can be configured (or predefined) to divide a determined total unpartitioned codebook size (e.g., by legacy rules for semi-static or dynamic codebooks). The WTRU can be configured with a segment size (e.g., n bits). In an example, the WTRU determines a total unpartitioned codebook size (e.g., size N) and can be based on a semi-static or dynamic codebook (e.g., in case of legacy WTRU behavior).

[0178] Reference Figure 3 In an embodiment, a WTRU can be configured to divide a total HARQ codebook into ceil(N / n) segments. In some examples, the WTRU can be configured (or predefined) with a mapping between one or more segments and one or more PRI. For example, as shown in Figure 3 The WTRU can transmit a codebook segment on the one or more PRI that the segment is mapped to. For example, the WTRU can transmit a total codebook on “n” PRIs. A receiver can implicitly determine which codebook segment (e.g., segment index) is transmitted from the PRI on which the segment is received.

[0179] Reference Figure 4In an embodiment, the WTRU can be configured to transmit a sub-group of codebook segments. For example, the WTRU can decide to skip a sub-group of “n” segments, e.g., determine not to transmit feedback for the skipped sub-group of codebook segments. For example, if the remaining LSB HARQ-ACK bits are all ACK or all NACK, the UE can skip transmitting the remaining segments and / or configure / set the extension bit to 0. In another example, the WTRU can skip transmission of segments that are typically all NACK or all ACK, as the receiver can determine the segment index from the mapped PRI. For each segment, the WTRU can include an extension bit (or concatenation indication bit) that indicates to the receiver whether more segments are expected or will be skipped from this codebook. The extension bit can also be understood as a termination bit for the receiver, e.g., to indicate to the receiver whether the segment is the last transmitted segment.

[0180] In an example, the extension bit can indicate to the receiver that all previous segments are skipped (e.g., not transmitted) as all HARQ feedback bits are, e.g., all ACK or all NACK. In another example, the extension bit can indicate to the receiver to skip all other segments (e.g., because all HARQ feedback bits are all ACK or all NACK).

[0181] In various embodiments, the WTRU can be further configured to bundle or aggregate the HARQ feedback for each segment to generate a single bit for each segment. For example, the WTRU can be configured to generate an ACK bit if all bits in the segment are ACK, or a NACK bit if at least one bit in the segment is NACK. In this example, the codebook size is determined or defined to be “n”.

[0182] Limited HARQ feedback on associated UL resources

[0183] In various embodiments, the WTRU can be configured with an association between one or more DL resources or HARQ processes and a physical channel (e.g., PUCCH or PUSCH) and / or certain uplink resources. The WTRU can be configured with an association between one or more DL SPS resources and one or more UL CGs. In an example, the WTRU can generate HARQ feedback for feedback reporting only on the associated UL resources.

[0184] For example, a WTRU can be configured with a mapping between SPS resources 1 and 2 and CG 1 by RRC signaling. For uplink slots within a TDD frame containing both CG 1 and a PUCCH resource, the WTRU generates HARQ feedback as UCI on PUSCH transmitted on CG 1 for all HARQ processes associated with DL SPS 1 and 2, and generates a HARQ feedback codebook for other processes transmitted on the PUCCH resource (e.g., other SPS resources or other dynamic DL assigned HARQ process IDs (PIDs)).

[0185] Codebook element grouping

[0186] In various embodiments, a WTRU can be configured to indicate a group of HARQ-ACK feedback bits that are transmitted or skipped by including an index (e.g., within a codebook). In an example, an index can be used (e.g., by a WTRU) to point to a group of HARQ-ACK feedback bits (e.g., a group of HARQ processes). In this example, the granularity with which a WTRU can skip a HARQ-ACK feedback bit can depend on the number of elements in each group of HARQ-ACK feedback bits.

[0187] In some examples, a HARQ-ACK group can be configurable. A HARQ-ACK group can be constructed by a WTRU based on a pre-defined rule. The grouping rule can be defined by at least one of:

[0188] • Priority of PDSCH. For example, each group can be composed of feedback bits for PDSCHs of the same or similar priority.

[0189] • Transmission parameters of PDSCH. For example, each group can be composed of feedback bits for PDSCHs using the same beam pair (e.g., quasi co-located or QCLed with the same RS, which means experiencing the same channel variation or similar characteristics of channel variation) or using the same time or frequency resources or using the same MCS or using the same transmission TRP, or using the same DM-RS.

[0190] • Feedback values. For example, a group can be composed of elements reporting the same HARQ-ACK value. A first group can be composed of only HARQ processes reporting NACK, and a second group can be composed of only HARQ processes reporting ACK.

[0191] • Timing for PDSCH transmission. For example, a group can be composed of feedback values for adjacent PDSCH transmissions. Thus, a group can not correspond to PDSCH transmissions that overlap in time.

[0192] • Size. A group can have a maximum size or a minimum size.

[0193] In some cases, the index used by the WTRU to report a group of HARQ-ACK feedback can identify the elements in the group and can be determined from the IDs of the elements in the group. For example, the WTRU can be configured to provide HARQ-ACK reporting only for acknowledged (ACKed) HARQ processes. In this example, the WTRU can construct a group index from the indices of the processes for which ACK is to be reported. The WTRU can need to report such a group index only in the codebook. In another example, the WTRU can be configured to determine two groups, a first group for processes associated with ACK and a second group for processes associated with NACK. The WTRU can report feedback only for the group with fewer or the fewest elements. The WTRU can construct a group index from the elements of the smaller group and can indicate in the codebook whether this group is for ACK or for NACK.

[0194] WTRU behavior when dropping HARQ-ACK feedback

[0195] Based on any of the methods or mechanisms described herein, the WTRU can not report HARQ-ACK feedback for all of its active HARQ processes. Thus, the UE can drop the feedback reporting bits and behave as if it indicated NACK to the network (e.g., gNB).

[0196] In one embodiment, the WTRU can hold the feedback reporting bits and transmit them at a later time. For example, the WTRU can hold a group of unreported feedback bits and can transmit them on a subsequent applicable resource (e.g., a subsequent PUCCH resource).

[0197] In another embodiment, the WTRU can create a group (e.g., a PDSCH group) for all feedback bits that are not (or have not been) transmitted in the expected feedback resource. The WTRU can maintain such a group and can transmit the applicable feedback in a special feedback resource configured for such a group. Alternatively, the WTRU can associate such a group with a preconfigured group ID (e.g., a PDSCH group ID) and can transmit feedback for that group when triggered by the gNB. The WTRU can expect such a triggering event to provide a feedback resource and the triggering event can also include the preconfigured group ID.

[0198] Reference Figure 5 In an example, the WTRU is configured with multiple DL SPS configurations, including a set of DL SPS configurations that are activated (e.g., a subset of the multiple DL SPS configurations). The WTRU can determine that the UCI payload is above a preconfigured threshold and / or the number of activated DL SPS (or set of DL SPS configurations) is above a preconfigured threshold. The WTRU then triggers HARQ codebook segmentation. As Figure 5As shown, for the first sub-codebook, the WTRU can determine to transmit a first subset of HARQ-ACKs, e.g., for HARQ-ACKs for TBs of DL SPS with high priority and / or low periodicity. For the second sub-codebook, the WTRU can determine to delay a second subset of HARQ-ACKs, e.g., for HARQ-ACKs for TBs of DL SPS with low priority and / or high periodicity. For the third sub-codebook, the WTRU can determine to skip / drop a third subset of HARQ-ACKs, e.g., for HARQ-ACKs for TBs of DL SPS that are not transmitted or skipped (e.g., based on a condition of not detecting DM-RS).

[0199] Representative procedures for HARQ feedback overhead reduction

[0200] In various embodiments, methods, apparatuses, and / or systems are disclosed for uplink control enhancements (e.g., feedback overhead reduction) in wireless communications. In one embodiment, a method for wireless communications (e.g., implemented in a WTRU 102) includes determining, by a WTRU (e.g., WTRU 102), that at least one triggering event for performing feedback overhead reduction has been satisfied, and performing, by the WTRU, feedback overhead reduction. In various embodiments, the method can include performing feedback overhead reduction including compressing, skipping, splitting, and / or delaying transmission of uplink control information (UCI) and / or one or more HARQ feedback bits.

[0201] In various embodiments, the triggering events (or triggering conditions) discussed herein can include any of the following: 1) a HARQ codebook, UCI payload, or feedback overhead is above a preconfigured threshold; 2) a number of activated DL SPS transmissions (or activated DL SPS configurations) is above a configured threshold; and / or 3) one or more time division duplexing (TDD) configurations.

[0202] In various embodiments, the triggering events (or triggering conditions) discussed herein can include any of the following: 1) one or more allocated resources for PUCCH transmission of a HARQ codebook or UCI transmission; 2) one or more allocated resources for PUSCH transmission of a HARQ codebook or UCI transmission; and / or 3) receiving an indication / message from a network (e.g., base station 114, eNodeB 160, or gNB 180).

[0203] In various embodiments, the triggering events (or triggering conditions) discussed herein can include any of the following: 1) receiving a bandwidth part (BWP) configuration; 2) receiving a BWP activation message; 3) receiving a BWP switching command; and / or 4) receiving a physical downlink shared channel (PDSCH) associated with a BWP different from a currently active BWP.

[0204] In various embodiments, the triggering event (or triggering condition) discussed herein can include any of the following: 1) determining that the WTRU is reporting HARQ feedback on one or more preconfigured component carriers (CCs); or 2) channel conditions reaching a predetermined level or one or more criteria; or 3) determining that at least one PDSCH or HARQ-ACK bit meets a feedback reduction criteria; or 4) determining that the WTRU has an ongoing L2 or L3 procedure.

[0205] In various embodiments, the method can include compressing the UCI or HARQ feedback, and computing a logical AND operation of all (or a subset) of HARQ feedback bits belonging to a HARQ codebook having a size of N bits. In various embodiments, the method can include skipping one or more HARQ feedback bits for a scheduled PDSCH or DM-RS transmission. In various embodiments, the method can include delaying transmission of HARQ-ACK feedback for a subset of HARQ processes. In various embodiments, when delaying the UCI or HARQ feedback, the method can further include transmitting the HARQ-ACK feedback in a different slot, sub-slot, and / or different PUCCH resource indication (PRI).

[0206] In various embodiments, the method can include performing feedback overhead reduction, including selecting one or more HARQ feedback bits to which to apply the feedback overhead reduction.

[0207] In various embodiments, a method for wireless communication (e.g., implemented in a WTRU 102) can include receiving information related to a set of downlink SPS configurations, receiving one or more downlink SPS transmissions based on the received information. The method can further include determining a payload of UCI for transmission on an uplink channel, and the payload including a set of HARQ feedback bits based on the received information, determining that at least one trigger condition for partitioning the set of HARQ feedback bits is satisfied, determining at least a portion of the set of HARQ feedback bits based on at least a downlink SPS configuration of the set of downlink SPS configurations, and the portion of the set of HARQ feedback bits corresponding to a portion of the received one or more downlink SPS transmissions. The method can further include transmitting at least the portion of the set of HARQ feedback bits using the uplink channel.

[0208] In various embodiments, the received information (e.g., received via DCI or RRC signaling) can include an indication to activate one or more downlink SPS transmissions (and / or downlink SPS configurations) using at least a downlink SPS configuration of the set of downlink SPS configurations.

[0209] In various embodiments, the triggering conditions (or triggering events) discussed herein (e.g., for splitting a set of HARQ feedback bits) can include any of: 1) determining a size of a payload of UCI (e.g., a size of N bits) is greater than or equal to a first preconfigured threshold; 2) determining a number of activated one or more downlink SPS transmissions is greater than or equal to a second preconfigured threshold; 3) receiving a BWP configuration; 4) receiving a BWP activation message; 5) receiving a BWP switching command; or 6) receiving a PDSCH or DM-RS transmission associated with a BWP different from a current active BWP.

[0210] In various embodiments, the downlink SPS configurations discussed herein can indicate a priority or periodicity of at least the activated one or more downlink SPS transmissions.

[0211] In various embodiments, the method can further include determining a first subset and a second subset of the set of HARQ feedback bits, wherein the first subset is associated with a first downlink SPS configuration of the set of downlink SPS configurations, the second subset is associated with a second downlink SPS configuration of the set of downlink SPS configurations, and the portion of the set of HARQ feedback bits includes any of the first subset or the second subset.

[0212] In various embodiments, the method can further include determining a first priority associated with the first downlink SPS configuration, determining a second priority associated with the second downlink SPS configuration, and determining the portion of the set of HARQ feedback bits including any of the first subset or the second subset of the set of HARQ feedback bits based on at least the first priority and the second priority. In various embodiments, the method can further include determining the portion of the set of HARQ feedback bits including the first subset of the set of HARQ feedback bits on a condition that the first priority is higher than the second priority.

[0213] In various embodiments, the method can further include delaying transmission of the second subset of the set of HARQ feedback bits on a condition that the second priority is lower than the first priority.

[0214] In various embodiments, the method can further include determining a first periodicity associated with the first downlink SPS configuration, determining a second periodicity associated with the second downlink SPS configuration, and determining the portion of the set of HARQ feedback bits including any of the first subset or the second subset based on at least the first periodicity and the second periodicity. In various embodiments, the method can further include determining the portion of the set of HARQ feedback bits including the first subset on a condition that the first periodicity is lower than the second periodicity.

[0215] In various embodiments, the method can further include delaying transmission of a second subset of the set of HARQ feedback bits on a condition that the second periodicity is higher than the first periodicity.

[0216] In various embodiments, when delaying transmission of the second subset, the method can further include transmitting the second subset of the set of HARQ feedback bits in a different slot, sub-slot, and / or using a different uplink channel.

[0217] In various embodiments, the method can further include determining a third subset of the set of HARQ feedback bits, and the third subset does not correspond to any of the received one or more downlink SPS transmissions. For example, the third subset of HARQ feedback bits can correspond to undetected DL SPS transmissions, such as PDSCH or DM-RS. The method can further include skipping transmission of the third subset of the set of HARQ feedback bits (e.g., not transmitting using the allocated uplink control channel resources).

[0218] In various embodiments, the uplink channel discussed herein can be a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). In various embodiments, the one or more downlink SPS transmissions discussed herein can include at least a physical downlink shared channel (PDSCH) transmission or a demodulation reference signal (DM-RS) transmission.

[0219] In various embodiments, the method can further include using the transmission of the portion of the set of HARQ feedback bits to indicate that transmission of another portion of the set of HARQ feedback bits is delayed or skipped. In various embodiments, the method can further include using an extension bit transmission to indicate that transmission of another portion of the set of HARQ feedback bits is delayed or skipped.

[0220] In various embodiments, a method (e.g., implemented in a WTRU 102) for wireless communication can include receiving one or more downlink SPS transmissions; determining a respective HARQ process ID for each of the received one or more downlink SPS transmissions; determining, based on the determined HARQ process IDs, a set of HARQ feedback bits to compress, and the set of HARQ feedback bits corresponding to at least a portion of the received one or more downlink SPS transmissions; and compressing the set of HARQ feedback bits into one or more bits.

[0221] In various embodiments, a method for wireless communication (e.g., implemented in a WTRU 102) can include receiving information related to a set of downlink SPS configurations and receiving one or more downlink SPS transmissions based on the received information. The method can further include determining a payload of UCI for transmission on an uplink channel and the payload including a set of HARQ feedback bits based on the received information. The method can further include determining that at least one trigger condition for partitioning the set of HARQ feedback bits is satisfied and determining at least a portion of the set of HARQ feedback bits based on at least a downlink SPS configuration of the set of downlink SPS configurations, where the determined portion of the set of HARQ feedback bits corresponds to a respective subset of the received one or more downlink SPS transmissions. The method can further include transmitting the determined portion of the set of HARQ feedback bits using the uplink channel.

[0222] In various embodiments, the received information includes an indication to activate one or more downlink SPS configurations of the set of downlink SPS configurations and the activated one or more downlink SPS configurations includes at least a downlink SPS configuration of the set of downlink SPS configurations. In one embodiment, each downlink SPS configuration of the activated one or more downlink SPS configurations indicates a respective priority or a respective periodicity associated with at least each respective downlink SPS configuration that is activated.

[0223] In various embodiments, the trigger condition (or trigger event) discussed herein (e.g., for partitioning a set of HARQ feedback bits) can include any of: 1) determining that a size of the payload of UCI is greater than or equal to a first preconfigured threshold; or 2) determining that a number of the activated one or more downlink SPS configurations is greater than or equal to a second preconfigured threshold.

[0224] In various embodiments, the method can further include determining a first subset of HARQ feedback bits and a second subset of HARQ feedback bits of the set of HARQ feedback bits, the first subset being associated with a first downlink SPS configuration, the second subset being associated with a second downlink SPS configuration of the set of downlink SPS configurations, and the determined portion of the set of HARQ feedback bits including any of the first subset of HARQ feedback bits or the second subset of HARQ feedback bits.

[0225] In various embodiments, the method can further include determining a first priority associated with the first downlink SPS configuration; determining a second priority associated with the second downlink SPS configuration; and selecting the first subset of HARQ feedback bits or the second subset of HARQ feedback bits to include in the determined portion of the set of HARQ feedback bits based on either of the first priority or the second priority. In one embodiment, the method can further include selecting the first subset of HARQ feedback bits to include in the determined portion of the set of HARQ feedback bits on a condition that the first priority is higher than the second priority. In another embodiment, the method can further include transmitting the second subset of HARQ feedback bits in a subsequent transmission opportunity or using a different uplink channel on a condition that the second priority is lower than the first priority.

[0226] In various embodiments, the method can further include determining a first periodicity associated with the first downlink SPS configuration; determining a second periodicity associated with the second downlink SPS configuration; and selecting the first subset of HARQ feedback bits or the second subset of HARQ feedback bits to include in the determined portion of the set of HARQ feedback bits based on either of the first periodicity or the second periodicity. In one embodiment, the method can further include selecting the first subset of HARQ feedback bits to include in the determined portion of the set of HARQ feedback bits on a condition that the first periodicity is lower than the second periodicity. In another embodiment, the method can further include transmitting the second subset of HARQ feedback bits in a subsequent transmission opportunity or using a different uplink channel on a condition that the second periodicity is higher than the first periodicity.

[0227] In various embodiments, the method can further include transmitting the first subset of HARQ feedback bits and the second subset of HARQ feedback bits in or using a different uplink channel: different time slots, different sub-slots.

[0228] In various embodiments, the method can further include determining a third subset of HARQ feedback bits of the set of HARQ feedback bits, the third subset of HARQ feedback bits not corresponding to any of the received one or more downlink SPS transmissions; and selecting the third subset of HARQ feedback bits to include in another portion of the set of HARQ feedback bits.

[0229] In various embodiments, the method can further include transmitting information using the determined portion of the set of HARQ feedback bits to indicate that transmission of another portion of the set of HARQ feedback bits is delayed or skipped. In various embodiments, the method can further include transmitting information using an extension bit to indicate that transmission of another portion of the set of HARQ feedback bits is delayed or skipped.

[0230] In various embodiments, a WTRU (e.g., WTRU 102 or UE) for wireless communication can include a receiver (e.g., transceiver 120 or transmit / receive element 122) configured to receive (or determine) information related to a set of downlink SPS configurations and receive one or more downlink SPS transmissions based on the received information. The WTRU can include a processor (e.g., processor 118) configured to determine a UCI payload for transmission on an uplink channel (e.g., PUCCH or PUSCH), the UCI payload including a set of HARQ feedback bits based on the received information, determine that at least one trigger condition for segmenting the set of HARQ feedback bits is satisfied, and determine at least a portion of the set of HARQ feedback bits based on at least a downlink SPS configuration of the set of downlink SPS configurations, the determined portion of the set of HARQ feedback bits corresponding to a respective subset of the received one or more downlink SPS transmissions. The WTRU can further include a transmitter (e.g., transceiver 120 or transmit / receive element 122) configured to transmit at least the determined portion of the set of HARQ feedback bits using the uplink channel.

[0231] In various embodiments, a WTRU (e.g., WTRU 102 or UE) can include a processor (e.g., processor 118), a transceiver (e.g., transceiver 120 or receiver and transmitter or transmit / receive element 122), and memory (e.g., non-removable memory 130 and / or removable memory 132) implementing any of the methods disclosed herein. The WTRU can also include any of the following: speaker / microphone 124, keypad 126, display / touchpad 128, power supply 134, global positioning system (GPS) chipset 136, and / or other peripherals 138, etc.

[0232] While features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein can be implemented in a computer program, software, or firmware incorporated in a computer- readable medium for execution by a computer or processor. Examples of non-transitory computer-readable storage media include a hard disk, a ROM, a RAM, a register, cache memory, semiconductor memory devices, magnetic media such as an internal hard disk and a removable disk, magneto-optical media, and computer-readable storage media such as a CD-ROM and a digital versatile disc (DVD). A processor in association with software can be used to implement a radio frequency transceiver for use in a WTRU 102, UE, terminal, base station, RNC, or any host computer.

[0233] Further, in the embodiments described above, processing platforms, computing systems, controllers, and other devices containing processors are noted. These devices can contain at least one central processing unit ("CPU") and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or instructions can be performed by the various CPUs and memories. Such acts and operations or instructions can be referred to as being "executed," "computer executed" or "CPU executed."

[0234] Those skilled in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. The electrical system representations, data bits, can result in the most

[0235] Data bits can also be maintained on computer-readable media including magnetic disks, optical disks, and any other volatile (e.g., random access memory ("RAM")) or non-volatile (e.g., read-only memory ("ROM")) mass storage system readable by the CPU. The computer-readable medium can include cooperating or interconnected computer-readable media, which exist exclusively in the processing system, or be distributed among multiple interconnected processing systems located in the same or different addresses continents. It is understood that the representative embodiments are not limited to the above-described memory, and that other platforms and memory can support the described methods.

[0236] In illustrative embodiments, any of the operations, processes, etc. described herein can be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions can be executed by a processor of a mobile unit, network element, and / or any other computing device.

[0237] There is little distinction between the use of hardware and software in the aspects of systems. The use of hardware or software is generally (e.g., but not always, since in certain contexts the choice between hardware and software can become significant) a design choice representing cost vs. efficiency tradeoffs. There can be various vehicles by which processes and / or systems and / or other technologies described herein can be effected (e.g., hardware, software, and / or firmware), and the preferred vehicle will vary with the context in which the processes and / or systems and / or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer can opt for a mainly hardware and / or firmware vehicle. If flexibility is paramount, the implementer can opt for a mainly software implementation. Alternatively, the implementer can opt for some combination of hardware, software, and / or firmware.

[0238] The above detailed description has set forth various embodiments of the devices and / or processes via the use of block diagrams, flowcharts, and / or examples. Insofar as such block diagrams, flowcharts, and / or examples contain one or more functions and / or operations, it will be understood by those within the art that each function and / or operation within such block diagrams, flowcharts, or examples can be implemented, individually and / or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Suitable processors include, by way of example, 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), Application Specific Standard Products (ASSPs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), and / or a state machine.

[0239] While features and elements are presented and described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the present disclosure is not limited to the specific embodiments described herein, which are presented as examples of the various aspects. Many modifications and variations are possible in light of the above teachings and can be employed apart from the specific embodiments described and disclosed. Only examples of compositions and methods capable of practicing various aspects of the disclosure are set forth and described in detail. No limitation is intended to the details of construction or arrangement of parts illustrated in the various embodiments. It is contemplated that in this disclosure and claims stemming therefrom, equivalents can be employed, and all such equivalents are intended to be within the scope of the disclosed aspects. Also, it will be understood that the present disclosure is directed to each individual feature, structural, and / or functional, as well as any combination of features, structural, and / or functional. Nothing in the specification should be construed as a limitation on the overall scope of inventive aspects presented by the disclosure. Various embodiments of the disclosure have been described as well as apparent variations thereof. None of the described elements, nor each and every combination thereof, is intended to be limiting. It is intended that only such limitations as appear in the claims shall apply.

[0240] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, when referred to herein, the term "station" and its abbreviation "STA," the term "user equipment" and its abbreviation "UE," can mean: (i) a wireless transmit and / or receive unit (WTRU), such as described below; (ii) any one of several implementations of a WTRU, such as described below; (iii) a device having wireless functionality and / or having wired functionality (e.g., tetherable) configured with some or all of the structure and functionality of a WTRU, in particular, as described below; (iii) a device having wireless functionality and / or having wired functionality configured with less than all of the structure and functionality of a WTRU, as described below; or (iv) the like. The following is with respect to Figures 1A-1D Details of an exemplary WTRU that can be representative of any UE described herein (or can be interchanged therewith) are provided.

[0241] In certain representative embodiments, portions of the subject matter described herein can be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and / or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and / or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein can be distributed as a program product in a variety of forms, and that the exemplary embodiments of the subject matter described herein apply regardless of the particular type of signal bearing media used to actually carry out the distribution. Examples of a signal bearing media include but are not limited to the following: a recordable type medium such as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a computer memory, etc.; and a transmission type medium such as a digital and / or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired

[0242] The subject matter described herein is sometimes illustrated using different components contained within, or in connection with, different other components. It will be appreciated that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermediate components. Likewise, any two components so associated can also be viewed as being "operably connected", or "operably coupled", to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being "operably couplable", to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and / or physically interacting components and / or wirelessly interactable and / or wirelessly interacting components and / or logically interacting and / or logically interactable components.

[0243] With respect to essentially any plural and / or singular terms used herein, a skilled artisan can convert from plural to singular and / or from singular to plural as appropriate according to context and / or application. Various singular / plural permutations are explicitly set forth herein for the sake of clarity.

[0244] Those skilled in the art will understand that, in general, the terminology used herein, particularly in the appended claims (e.g., the body of the appended claims), is typically intended as “open-ended” terms (e.g., the term “comprising” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “including” should be interpreted as “including but not limited to,” etc.). Those skilled in the art will also understand that if it is intended to specify a particular number of introduced claim objects, such intention will be explicitly stated in the claims, and if no such claim objects are present, such intention will not exist. For example, the term “single” or similar language may be used where only one item is anticipated. To aid understanding, the appended claims and / or the description herein may contain the use of the introductory phrases “at least one” and “one or more” to introduce claim objects. However, the use of such phrases should not be construed as implying that any particular claim containing such introduced claim objects is limited to an embodiment containing only one such claim object by using the indefinite articles “a” or “an.” This is true even when the same claim includes the introductory phrase "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and / or "an" should be interpreted as meaning "at least one" or "one or more"). The same applies to the use of definite articles used to introduce the subject matter of a claim. Furthermore, even when a specific number of the introduced subject matter of a claim is explicitly stated, those skilled in the art will recognize that such a statement should be interpreted as meaning at least the stated number (e.g., a bare statement of "two subject matters" without other modifiers means at least two subject matters, or two or more subject matters).

[0245] Additionally, in those instances in which examples similar to the convention of“A, B, and C, etc.” are used, generally the meaning of such a construction will be understood by those of ordinary skill in the art to mean that at least one ofA, B, or C is an applicable example (e.g., a system having at least one ofA, B, or C would include but not be limited to a system having A alone, a system having B alone, a system having C alone, a system having both A and B, a system having both A and C, a system having both B and C, and / or a system having all of A, B, and C etc.). In those instances in which examples similar to the convention of“A, B, or C, etc.” are used, generally the meaning of such a construction will be understood by those of ordinary skill in the art to mean that at least one ofA, B, or C is an applicable example (e.g., a system having at least one ofA, B, or C would include but not be limited to a system having A alone, a system having B alone, a system having C alone, a system having both A and B, a system having both A and C, a system having both B and C, and / or a system having all of A, B, and C etc.). Those of ordinary skill in the art will further appreciate that, in fact, any disjunctive word and / or phrase presenting two or more alternative terms will be construed to possibly include one of the terms, any of the terms, or the possibility of both terms, whether in the description, claims, or drawings of the document. For example, the phrase“A or B” will be construed to possibly include“A,” or“B,” or“A and B.” Additionally, as used herein, the term“any of” followed by a listing of multiple items and / or categories of items, is intended to include any one of the listed items individually, or any combination of the listed items, or any number of items from the listed items, and / or any number of items from the listed items in combination with any number of items from other categories of items. Further, as used herein, the term“set” or“group” is intended to include any number of items, including zero. Additionally, as used herein, the term“number” is intended to include any number, including zero.

[0246] Additionally, where features or aspects of the disclosure are described in terms of Markush groups, a person of ordinary skill in the art will recognize from the disclosure that the disclosure is also described in terms of any individual member or subgroup of members of the Markush group.

[0247] As those skilled in the art will appreciate, all ranges disclosed herein are also contemplated as individual possible subranges and combinations of subranges, for any and all purposes, such as to provide written description for claim purposes. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least two equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be easily broken down into a lower third, middle third, and upper third, etc. As will also be understood by those skilled in the art, all language such as "up to," "at least," "greater than," "less than," and the like includes the number recited and refers to ranges that can be subsequently broken down into subranges as described above. Finally, as will also be understood by those skilled in the art, a range includes each individual number in that range. Thus, for example, a group having 1 to 3 members is a group having 1, 2, or 3 members. Similarly, a group having 1 to 5 members is a group having 1, 2, 3, 4, or 5 members, etc.

[0248] Furthermore, unless otherwise indicated, the claims are not to be constructed as being limited by the ordering of the cases or elements. Also, where a term is used in the singular, "a" or "an" the inventors also contemplate pluralities or multiples thereof, unless otherwise indicated. Furthermore, the terms "comprise", "have", "with", "contain", "hold", "maintain", "carry" and the like can have the meaning ascribed to them in U.S. Patent law and can mean including, in an open, inclusive way, for example, that a composition, an element or other feature can comprise several elements, not necessarily all of which are required. or means plus function claim format, and no claim in this application is intended to be interpreted only under the provisions for means plus function claims under 35 U.S.C. § 112, sixth paragraph.

[0249] The processor in association with software can be used to implement a radio frequency transceiver in a wireless transmit receive unit (WTRU), a user equipment (UE), terminal, base station, mobility management entity (MME) or an evolved packet core (EPC), or any host computer. The WTRU can be used in conjunction with modules, implemented in hardware and / or software including a software defined radio (SDR), and other components such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a near field communication (NFC) module, a liquid crystal display (LCD) display module, an organic light emitting diode (OLED) display module, a digital music player, a media player, a video game player module, an Internet browser, and / or any wireless local area network (WLAN) or Ultra Wide Band (UWB) module.

[0250] While the application has been described in terms of a communication system, it is contemplated that the system can be implemented in software on a microprocessor / general purpose computer (not shown). In certain embodiments, one or more of the functions of the various components can be implemented in software that controls the general purpose computer.

[0251] In addition, although this application is illustrated and described herein with reference to specific embodiments, the application is not intended to be limited to the details shown. Rather, various modifications can be made in the details within the scope and range of equivalents of the claims and without departing from the application.

[0252] Throughout this disclosure, the skilled person will appreciate that certain representative embodiments can be used in alternative forms or in combination with other representative embodiments.

[0253] Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in combination with others dependent upon the circumstances. The methods described herein can be implemented in a computer program, software, or firmware incorporated in a computer- readable medium for execution by a computer or processor. Examples of non-transitory computer-readable storage media include a hard disk, a floppy disk, a magnetic disk, a magnetic tape, a cassette tape, an optical disk such as a compact disk (CD) or digital versatile disk (DVD), a punch card, a paper tape, and a memory such as read-only memory (ROM), random access memory (RAM), a programmable read-only memory (PROM), and erasable programmable read-only memory (EPROM). The processor can be a hardware device, such as a microprocessor, digital signal processor, microcontroller, or other processing circuitry, provided for the user equipment.

[0254] Furthermore, in the embodiments described above, processing platforms, computing systems, controllers, and other devices containing processors are noted. These devices can contain at least one Central Processing Unit ("CPU") and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or instructions can be expressed as utilizing various CPU and memory that are in operative connection, arranged to be in operative connection, and / or other hardware mechanisms configured to perform the calculations, techniques, or processes. Such acts can be referred to as being "executed" by the CPU or other hardware mechanisms.

[0255] One of ordinary skill in the art will appreciate that acts and symbolic representations of operations or instructions include the manipulation of electrical signals representing data bits by the CPU. Such manipulation can include the manipulation of magnetic bits represented by a magnetic storage medium, the manipulation of optical bits represented by a optical storage medium, the manipulation of atomic or sub-atomic particles representing states or conditions, and the like. The acts and symbolically represented operations or instructions manipulate or transform data represented as physical electronic, magnetic, optical, or organic entities.

[0256] Data bits can also be maintained on a computer readable medium including any volatile (e.g., random access memory ("RAM")) or non-volatile (e.g., read-only memory ("ROM")) mass storage system readable by the CPU. The computer readable medium can include cooperating or interconnected computer readable media, which exist exclusively in the processing system, or distributed among multiple interconnected processing systems, which can be local or remote to the processing system. It will be appreciated that representative embodiments are not limited to the above-mentioned memory or storage, and that other platforms and memories can support the described methodology.

[0257] Suitable processors include, by way of illustration and not limitation, general purpose processors, special purpose processors, conventional processors, digital signal processors (DSP), multiple microprocessors, one or more microprocessors in association with a DSP core, controllers, micro-controllers, application specific integrated circuits (ASICs), application specific standard products (ASSPs), field programmable gate array (FPGA) circuits, any other type of integrated circuit (IC), and / or state machines.

[0258] While the application has been described in terms of a communication system, it is contemplated that the system can be implemented in software on a microprocessor / general purpose computer (not shown). In certain embodiments, one or more of the functions of the various components can be implemented in software that controls the general purpose computer.

[0259] In addition, although the present application has been described in reference to specific embodiments, it is not intended to be limited to the details described. Rather, various modifications can be effected without departing from the spirit and scope of the application.

Claims

1. A method for wireless communication implemented by a wireless transmit / receive unit (WTRU), the method comprising: receiving configuration information including an indication to activate one or more downlink semi-persistent scheduling (SPS) configurations of a set of downlink SPS configurations; determining a payload size of uplink control information (UCI) for an uplink transmission, wherein the UCI indicates a set of hybrid automatic repeat request (HARQ) feedback bits associated with one or more downlink transmissions; determining at least a portion of the set of HARQ feedback bits to be transmitted based on at least one of: the payload size of the UCI being greater than or equal to a first threshold, or a number of activated downlink SPS configurations being greater than or equal to a second threshold, wherein the at least a portion of the set of HARQ feedback bits is associated with at least one activated downlink SPS configuration and corresponds to a subset of the one or more downlink transmissions; using the uplink transmission to transmit at least the portion of the set of HARQ feedback bits.

2. The method of claim 1, further comprising activating one or more downlink SPS configurations of the set of downlink SPS configurations.

3. The method of claim 2, wherein the determining at least the portion of the set of HARQ feedback bits to be transmitted comprises: segmenting the set of HARQ feedback bits based on at least one of: the payload size of the UCI being greater than or equal to the first threshold, or the number of activated downlink SPS configurations being greater than or equal to the second threshold.

4. The method of claim 3, wherein the segmenting the set of HARQ feedback bits is further based on any of: receiving a bandwidth part (BWP) configuration; receiving a BWP activation message; receiving a BWP switching command; or receiving a physical downlink shared channel (PDSCH) transmission associated with a BWP different from a currently active BWP.

5. The method of claim 2, wherein each of the activated one or more downlink SPS configurations indicates at least a respective priority or a respective periodicity associated with the activated respective downlink SPS configuration.

6. The method of claim 2, wherein the at least one activated downlink SPS configuration comprises a first activated downlink SPS configuration, and the method further comprises: determining a first subset of HARQ feedback bits and a second subset of HARQ feedback bits of the set of HARQ feedback bits, wherein the first subset is associated with the first activated downlink SPS configuration, the second subset is associated with a second activated downlink SPS configuration of the set of downlink SPS configurations, and wherein the at least a portion of the set of HARQ feedback bits comprises any of the first subset of HARQ feedback bits or the second subset of HARQ feedback bits.

7. The method of claim 6, further comprising: ​ determining a first priority associated with the first activated downlink SPS configuration; determining a second priority associated with the second activated downlink SPS configuration; and selecting between the first subset of HARQ feedback bits and the second subset of HARQ feedback bits to be included in the at least portion of the set of HARQ feedback bits based on either the first priority or the second priority.

8. The method of claim 7, further comprising: selecting the first subset of HARQ feedback bits to be included in the at least portion of the set of HARQ feedback bits based on the first priority being higher than the second priority.

9. The method of claim 7, further comprising: transmitting the second subset of HARQ feedback bits in a subsequent transmission opportunity or using a different uplink channel based on the second priority being lower than the first priority.

10. The method of claim 6, further comprising: determining a first periodicity associated with the first activated downlink SPS configuration; determining a second periodicity associated with the second activated downlink SPS configuration; and selecting between the first subset of HARQ feedback bits and the second subset of HARQ feedback bits to be included in the at least portion of the set of HARQ feedback bits based on either the first periodicity or the second periodicity.

11. The method of claim 10, further comprising: selecting the first subset of HARQ feedback bits to be included in the at least portion of the set of HARQ feedback bits based on the first periodicity being lower than the second periodicity.

12. The method of claim 10, further comprising: transmitting the second subset of HARQ feedback bits in a subsequent transmission opportunity or using a different uplink channel based on the second periodicity being higher than the first periodicity.

13. The method of claim 6, further comprising: transmitting the first subset of HARQ feedback bits and the second subset of HARQ feedback bits in or using a different uplink channel in any of: different slots, different sub-slots.

14. The method of claim 6, further comprising: determining a third subset of HARQ feedback bits of the set of HARQ feedback bits, wherein the third subset of HARQ feedback bits does not correspond to any of the one or more downlink transmissions; and selecting the third subset of HARQ feedback bits to be included in another portion of the set of HARQ feedback bits.

15. The method of claim 1, further comprising: transmitting information using the at least portion of the set of HARQ feedback bits to indicate that transmission of another portion of the set of HARQ feedback bits is delayed or skipped.

16. A wireless transmit / receive unit (WTRU) for wireless communication, the WTRU comprising circuitry, the circuitry comprising a transmitter, a receiver, a processor, and a memory, configured to: receive configuration information comprising an indication to activate one or more downlink semi-persistent scheduling (SPS) configurations of a set of downlink SPS configurations; determine a payload size of uplink control information (UCI) for an uplink transmission, wherein the UCI indicates a set of hybrid automatic repeat request (HARQ) feedback bits associated with one or more downlink transmissions; determine at least a portion of the set of HARQ feedback bits to be transmitted based on at least one of: the payload size of the UCI being greater than or equal to a first threshold, or a number of activated downlink SPS configurations being greater than or equal to a second threshold, wherein the at least a portion of the set of HARQ feedback bits is associated with at least one activated downlink SPS configuration and corresponds to a subset of the one or more downlink transmissions; and transmit at least the portion of the set of HARQ feedback bits using the uplink transmission.

17. The WTRU of claim 16, wherein the WTRU is further configured to split the set of HARQ feedback bits based on any of: 1) the payload size of the UCI being greater than or equal to the first threshold, or 2) the number of activated downlink SPS configurations being greater than or equal to the second threshold.

18. The WTRU of claim 16, wherein the uplink transmission is a physical uplink control channel (PUCCH) transmission or a physical uplink shared channel (PUSCH) transmission, and wherein the one or more downlink transmissions comprise at least a physical downlink shared channel (PDSCH) transmission or a demodulation reference signal (DM-RS) transmission.

19. The WTRU of claim 16, the WTRU further configured to: transmit information using the at least a portion of the set of HARQ feedback bits to indicate that transmission of another portion of the set of HARQ feedback bits is delayed or skipped; or transmit information using extension bits to indicate that transmission of another portion of the set of HARQ feedback bits is delayed or skipped. ​ ​ ​ ​ ​ ​ ​

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