EP4552421A1

EP4552421A1 - Methods for supporting low power extended reality

Info

Publication number: EP4552421A1
Application number: EP23762072.9A
Authority: EP
Inventors: Tejaswinee LUTCHOOMUN; Jaya Rao; Dylan WATTS; Ahmed Mostafa
Original assignee: InterDigital Patent Holdings Inc
Current assignee: InterDigital Patent Holdings Inc
Priority date: 2022-08-08
Filing date: 2023-08-07
Publication date: 2025-05-14
Also published as: CN119866663A; WO2024035632A1

Abstract

A method performed by a wireless transmit/receive unit (WTRU) includes receiving configuration information for a configured grant for small data transfers (CG-SDT) to be performed in the Inactive state, receiving PDU sets having PDU set information for each PDU set, determining that the received CG-SDT cannot accommodate transmission of uplink data of the PDU sets, determining a modified physical downlink control channel (PDCCH) monitoring time duration to be used by the WTRU, and transmitting a request for a second CG-SDT to transmit uplink data in the Inactive state.

Description

METHODS FOR SUPPORTING LOW POWER EXTENDED REALITY

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of US provisional patent application Nos. 63/527,402 filed on 18 July 2023 and 63/395,905 filed on 08 August 2022, each of which is incorporated herein by reference.

FIELD

[0002] This disclosure pertains to methods and apparatus for supporting low power operations of a wireless transmit/receive unit in an extended reality environment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] A more detailed understanding may be had from the detailed description below, given by way of example in conjunction with drawings appended hereto. Figures in such drawings, like the detailed description, are examples. As such, the Figures (FIGs.) and the detailed description are not to be considered limiting, and other equally effective examples are possible and likely. Furthermore, like reference numerals ("ref.") in the FIGs. indicate like elements, and wherein: [0004] FIG. 1 A is a system diagram illustrating an example communications system;

[0005] FIG. IB is a system diagram illustrating an example wireless transmit/receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1 A;

[0006] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A;

[0007] FIG. ID is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A;

[0008] FIG. 2 is an example flow diagram of a method according to a first embodiment of the disclosure;

[0009] FIG. 3 is an example flow diagram of a method according to a second embodiment of the disclosure;

[0010] FIG. 4 is an example flow diagram of a method according to a third embodiment of the disclosure;

[0011] FIG. 5 is an example flow diagram of a method according to a fourth embodiment of the disclosure; [0012] FIG 6 is an example flow diagram of a method according to a fifth embodiment of the disclosure; and

[0013] FIG. 7 is a depiction of a timing diagram according to an embodiment of the disclosure.

DETAILED DESCRIPTION

Introduction

[0014] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments and/or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components and circuits have not been described in detail, so as not to obscure the following description. Further, embodiments and examples not specifically described herein may be practiced in lieu of, or in combination with, the embodiments and other examples described, disclosed or otherwise provided explicitly, implicitly and/or inherently (collectively "provided") herein. Although various embodiments are described and/or claimed herein in which an apparatus, system, device, etc. and/or any element thereof carries out an operation, process, algorithm, function, etc. and/or any portion thereof, it is to be understood that any embodiments described and/or claimed herein assume that any apparatus, system, device, etc. and/or any element thereof is configured to carry out any operation, process, algorithm, function, etc. and/or any portion thereof.

Example Communications System

[0015] The methods, apparatuses and systems provided herein are well-suited for communications involving both wired and wireless networks. An overview of various types of wireless devices and infrastructure is provided with respect to FIGs. 1A-1D, where various elements of the network may utilize, perform, be arranged in accordance with and/or be adapted and/or configured for the methods, apparatuses and systems provided herein.

[0016] FIG. 1A is a system diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), singlecarrier FDMA (SC-FDMA), zero-tail (ZT) unique-word (UW) discreet Fourier transform (DFT) spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block- filtered OFDM, filter bank multicarrier (FBMC), and the like. [0017] As shown in FIG. 1A, the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104/113, a core network (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 may be any type of device configured to operate and/or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station" and/or a "STA", may be configured to transmit and/or receive wireless signals and may include (or be) a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0018] The communications systems 100 may also include a base station 114a and/or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d, e.g., to facilitate access to one or more communication networks, such as the CN 106/115, the Internet 110, and/or the networks 112. By way of example, the base stations 114a, 114b may be any of a base transceiver station (BTS), a Node-B (NB), an eNode-B (eNB), a Home Node-B (HNB), a Home eNode-B (HeNB), a gNode-B (gNB), a NR Node-B (NR NB), a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements.

[0019] The base station 114a may be part of the RAN 104/113, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and/or the base station 114b may be configured to transmit and/or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in an embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each or any sector of the cell. For example, beamforming may be used to transmit and/or receive signals in desired spatial directions.

[0020] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0021] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104/113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

[0022] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A) and/or LTE-Advanced Pro (LTE-A Pro).

[0023] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access, which may establish the air interface 116 using New Radio (NR).

[0024] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and/or transmissions sent to/from multiple types of base stations (e.g., an eNB and a gNB). [0025] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (Wi-Fi), IEEE 802.16 (i.e., 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.

[0026] The base station 114b in FIG. 1 A may be a wireless router, Home Node-B, Home eNode- B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish any of a small cell, picocell or femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106/115.

[0027] The RAN 104/113 may be in communication with the CN 106/115, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106/115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104/113 and/or the CN 106/115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104/113 or a different RAT. For example, in addition to being connected to the RAN 104/113, which may be utilizing an NR radio technology, the CN 106/115 may also be in communication with another RAN (not shown) employing any of a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0028] The CN 106/115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and/or other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and/or the internet protocol (IP) in the TCP/IP internet protocol suite. The networks 112 may include wired and/or wireless communications networks owned and/or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104/114 or a different RAT.

[0029] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1 A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0030] FIG. IB is a system diagram illustrating an example WTRU 102. As shown in FIG. IB, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keypad 126, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and/or other elements/peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0031] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit/receive element 122. While FIG. IB depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together, e.g., in an electronic package or chip.

[0032] The transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in an embodiment, the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals. In an embodiment, the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example. In an embodiment, the transmit/receive element 122 may be configured to transmit and/or receive both RF and light signals. It will be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.

[0033] Although the transmit/receive element 122 is depicted in FIG. IB as a single element, the WTRU 102 may include any number of transmit/receive elements 122. For example, the WTRU 102 may employ MIMO technology. Thus, in an embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0034] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0035] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0036] The processor 118 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like. [0037] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0038] The processor 118 may further be coupled to other elements/peripherals 138, which may include one or more software and/or hardware modules/units that provide additional features, functionality and/or wired or wireless connectivity. For example, the elements/peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (e.g., for photographs and/or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and/or augmented reality (VR/AR) device, an activity tracker, and the like. The elements/peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and/or a humidity sensor.

[0039] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the uplink (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and/or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the uplink (e.g., for transmission) or the downlink (e.g., for reception)).

[0040] FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106. [0041] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0042] Each of the eNode-Bs 160a, 160b, and 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and/or downlink (DL), and the like. As shown in FIG. 1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0043] The CN 106 shown in FIG. 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any one of these elements may be owned and/or operated by an entity other than the CN operator.

[0044] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an SI interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and/or WCDMA.

[0045] The SGW 164 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via the SI interface. The SGW 164 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0046] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0047] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers.

[0048] Although the WTRU is described in FIGs. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network. [0049] In representative embodiments, the other network 112 may be a WLAN.

[0050] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a distribution system (DS) or another type of wired/wireless network that carries traffic into and/or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and/or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802. l ie DLS or an 802.1 Iz tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an "ad-hoc" mode of communication.

[0051] When using the 802.1 lac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier sense multiple access with collision avoidance (CSMA/CA) may be implemented, for example in in 802.11 systems. For CSMA/CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed/detected and/or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0052] High throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadj acent 20 MHz channel to form a 40 MHz wide channel.

[0053] Very high throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz, and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse fast fourier transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above-described operation for the 80+80 configuration may be reversed, and the combined data may be sent to a medium access control (MAC) layer, entity, etc.

[0054] Sub 1 GHz modes of operation are supported by 802.1 laf and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.1 laf and 802.1 lah relative to those used in

802.1 In, and 802.1 lac. 802.1 laf supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV white space (TVWS) spectrum, and 802.1 lah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment,

802.1 lah may support meter type control/machine-type communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and/or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0055] WLAN systems, which may support multiple channels, and channel bandwidths, such as

802.1 In, 802.1 lac, 802.1 laf, and 802.1 lah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and/or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.1 lah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and/or other channel bandwidth operating modes. Carrier sensing and/or network allocation vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0056] In the United States, the available frequency bands, which may be used by 802.1 lah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.1 lah is 6 MHz to 26 MHz depending on the country code.

[0057] FIG. ID is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0058] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and/or receive signals from the WTRUs 102a, 102b, 102c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and/or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and/or gNB 180c).

[0059] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, OFDM symbol spacing and/or OFDM subcarrier spacing may vary for different transmissions, different cells, and/or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., including a varying number of OFDM symbols and/or lasting varying lengths of absolute time). [0060] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and/or a non- standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non- standalone configuration WTRUs 102a, 102b, 102c may communicate with/connect to gNBs 180a, 180b, 180c while also communicating with/connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and/or throughput for servicing WTRUs 102a, 102b, 102c.

[0061] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and/or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, and the like. As shown in FIG. ID, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0062] The CN 115 shown in FIG. ID may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and at least one Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and/or operated by an entity other than the CN operator.

[0063] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b, e.g., to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for MTC access, and/or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP access technologies such as Wi-Fi.

[0064] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183 a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP -based, non-IP based, Ethernet-based, and the like.

[0065] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, e.g., to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multihomed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0066] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers. In an embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0067] In view of FIGs. 1 A-1D, and the corresponding description of FIGs. 1 A-1D, one or more, or all, of the functions described herein with regard to any of: WTRUs 102a-d, base stations 114a- b, eNode-Bs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a- b, SMFs 183a-b, DNs 185a-b, and/or any other element(s)/device(s) described herein, may be performed by one or more emulation elements/devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and/or to simulate network and/or WTRU functions.

[0068] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and/or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and/or deployed as part of a wired and/or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented/deployed as part of a wired and/or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and/or may performing testing using over-the-air wireless communications.

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

[0070] Examples provided herein do not limit applicability of the subj ect matter to other wireless technologies, e.g., using the same or different principles as may be applicable.

[0071] As explained herein, a wireless transmit/receive unit (WTRU) may be an example of a user equipment (UE). Hence the terms UE and WTRU may be used with equal scope herein.

Extended Reality

[0072] The term extended Reality (XR) is an umbrella term for different types of immersive experiences including Virtual Reality (VR), Augmented Reality (AR) and Mixed Reality (MR) and the realities interpolated among them. Virtual Reality (VR) is a rendered version of a delivered visual and audio scene. The rendering is designed to mimic the visual (e.g. stereoscopic 3D) and audio sensory stimuli of the real world as naturally as possible to an observer or user as they move within the limits defined by the application. Augmented Reality (AR) is when a user is provided with additional information or artificially generated items or content overlaid upon their current environment. Mixed Reality (MR) is an advanced form of AR where some virtual elements are inserted into the physical scene with the intent to provide the illusion that these elements are part of the real scene. XR may include to all real-and-virtual combined environments and humanmachine interactions generated by computer technology and wearables.

[0073] The notion of immersion in the context of XR applications/services refers to the sense of being surrounded by the virtual environment as well as providing the feeling of being physically and spatially located in the virtual environment. The levels of virtuality may range from partial sensory inputs to fully immersive multi-sensory inputs leading to a virtual reality practically indiscernible from actual reality.

[0074] XR devices may be typically associated with capabilities that offer various degrees of spatial tracking. XR devices may be equipped with various sensors to enable spatial tracking, for example monocular/stereo/depth cameras, radio beacons, GPS, inertial sensors etc. Possibly such spatial tracking may be performed at different levels, e.g. 3 Degrees of Freedom - DoF (i.e. rotational motion along X, Y and Z axis), 6 DoF (i.e. rotational and/or translational motion along X, Y and Z axis). Possibly such spatial tracking may result in an interaction to experience some form of virtual content. The user may act in and/or interact with the components within extended reality. For example, the actions and/or interactions may involve movements, gestures, eye tracking etc. Spatial tracking is an important enabler for immersive XR experience. For example, some form of head and/or motion tracking may ensure that the simulated visual and audio components from the user perspective are updated to be consistent with user's movements. Imprecise and/or delayed spatial tracking may lead to sensation of discomfort and/or motion sickness for the user.

[0075] In this disclosure, a WTRU may correspond to any XR device/node which may come in variety of form factors. Typical WTRU (e.g. XR WTRU) may include, but not limited to the following: Head Mounted Displays (HMD), optical see-through glasses and camera see-through HMDs for AR and MR, mobile devices with positional tracking and camera, wearables etc. In addition to the above, several different types of XR WTRU may be envisioned based on XR device functions for e.g. as display, camera, sensors, sensor processing, wireless connectivity, XR/Media processing, power supply etc. to be provided by one or more devices, wearables, actuators, controllers and/or accessories. One or more device/nodes/WTRUs may be grouped into a collaborative XR group for supporting any of XR applications/services.

XR Traffic

[0076] XR traffic may have the following characteristics: (a) XR Traffic may include different frames (e.g., I-frames, P-frames, B-frames, etc.), (b) I-frames and P-frames may be mapped to one flow, or they may be mapped to different flows depending on the traffic model (3 GPP TR 38.838) such as being (i) Slice-based: In this encoding scheme, a single video frame is divided into N slices. Out of N, one slice is I slice and remaining N-l slices are P slices, (ii) GOP -based: In this encoding scheme, a single video frame is either I frame or P frame, (c) I-frames may generally be larger in size as compared to P-frames. (d) XR Traffic may include PDU sets where one PDU-set include one or more PDUs. (e) Different PDU-sets may have different PDU-set delay bound (PSDB) and/or different PDU-set error rate requirements (PSER).

XR Definitions

[0077] XR experience: overall experience of the end user, resulting from transmission and/or reception of the correct data to the correct end device in a reliable and timely manner.

[0078] XR action: 'XR action' as used in this disclosure refers to any one or more task(s) performed by the WTRU to enable the XR experience.

[0079] Data unit: Throughout this disclosure, a data unit refers to a frame and/or PDU and/or PDU-set and/or group of PDU-sets.

[0080] Event: an event may, for example, result in a change in the current mode of operation/transmission/reception of data that may require a change in resource allocation, statically, semi -statically or dynamically (e.g., change in resource grant allocation, change in periodicity of configured grant (CG and/or CG-SDT), application of offset to resource grant allocation, etc.). Examples of when an 'event' may be detected may include any of the following: [0081] WTRU may receive an indication from application of an expected delay due to jitter in the UL (e.g., as a result of processing delay from codec in AR glasses/VR headset)

[0082] WTRU may detect presence of jitter exceeding the allowed delay budget based on reception of the previous DL transmission

[0083] Detection of an event may be based on the timing of the arrival of data from the application being outside of the expected window of arrival, based on measurements by the WTRU. This may lead the WTRU to alter/request for a change in the mode of resource grant allocation.

ISSUES ARISING IN EXTENDED REALITY (XR)

[0084] The following may be issues in an XR environment, (a) XR WTRUs typically operate in connected state/mode for extended periods of time for frequent UL and DL data transmissions. This can lead to constraints in the amount of power saving that can be achieved, exacerbated by form factor restrictions for XR WTRUs. (b) XR problems: QoS maintenance, supporting large payload, maximizing power saving, (c) Less monitoring of DCI in Inactive state due to longer DRX off cycle times as compared to RRC Connected state, (d) Latency to transition from RRC Inactive state to RRC Connected state is less than latency to transition from RRC Idle state to RRC Connected state (no need for CN registration), (e) Enabling transmissions in inactive state/mode for XR may present a good compromise solution to meet XR QoS requirements while improving power savings, (f) RAN awareness of application layer parameters (XR traffic characteristics) will be leveraged in XR enhancements, (g) Different types/classes of WTRU being considered for XR to support high downlink/uplink throughputs, low latency and high reliability.

METHODS FOR SUPPORTING LOW POWER XR

[0085] All procedures described in this disclosure may occur in a semi-static or dynamic manner, once or multiple times, at the start and/or throughout the XR session/experience.

Parameters to determine operation in low-power state

[0086] Overview of operation in low-power state

[0087] The following (a)-(c) are descriptions of operations in XR.

[0088] (a). Low power state: Throughout this disclosure, low power state refers to any state other than the RRC Connected state. In an example, it may refer to the RRC Inactive state. In another example, it may refer to RRC Idle state. In another example, it may refer to a state in between the RRC Connected state and the RRC Inactive state where the level of DCI monitoring of the WTRU is between the typical levels for RRC Connected state and RRC Inactive state.

[0089] (b). Different class/type of XR WTRU: Throughout this disclosure, the XR WTRU may be a regular WTRU and/or a reduced-capability WTRU and/or a WTRU designed to support high uplink and high downlink throughputs, low latency and high reliability while maximizing its power saving margins. The WTRU may be a regular smartphone or a wearable pair of AR glasses. In an example, the WTRU may have a lower number of Transmit antennas (e.g. 1 Tx antenna) and/or Receive antennas (e.g., 2 Rx antennas) as compared to a regular WTRU (e.g., 2 Tx and/or 4 Rx antennas) to extend its battery life and improve its thermal management (especially in the case of wearables).

[0090] (c). There may be some requirements/preferences/conditions associated with the XR WTRU belonging to a different class of WTRU. (i) In an example, as a result of being designed to support high uplink/downlink throughputs, low latency and high reliability while achieving good power saving gains, the WTRU may prioritize operation in a low power state and minimize the amount of time (e.g., measured in terms of length of time or number of cycles/slots) it spends in RRC Connected state, (ii) In an example, the network may be made aware of the WTRU class/type through registration or initial capabilities exchange with the WTRU (e.g., in RRC). The network may know that serving this class of WTRU requires scheduling in a way to maximize to sleep/off cycle periods of the WTRU. As a result, the network may also prioritize operation in a low power state for the WTRU. (iii) Transitioning in between states for the WTRU may be WTRU-initiated. In an example, the WTRU may be aware of the predictable nature of the upcoming XR traffic to be sent in the UL (e.g., from indications from the XR applications). As a result, it may send a request to the gNB to be transitioned into a low power state, (iv) Transitioning in between states for the WTRU may be network-initiated. In an example, the network may receive indications from the WTRU about the XR traffic characteristics of the traffic generated in the WTRU such that the network may determine that the WTRU may operate in a low power state and still be able to successfully transmit its UL data. In another example, the network may determine to transition the WTRU to a low power state based on observation of past XR traffic patterns sent in the UL. In another example, the network may determine to transition the WTRU to a low power state based on the upcoming downlink XR traffic. The network may receive statistics from the XR server on the traffic characteristics or it may determine that a low power operating mode may be appropriate based on observation of past XR traffic pattern sent to the WTRU in the DL. In another example, the network may determine to transition the WTRU to a low power state based on joint knowledge of UL and DL traffic.

[0091] RAN awareness of XR traffic characteristics, QoS metrics and application later attributes RAN awareness of the PDUs belonging to the same XR frame (which may include one PDU-set) as well as the interrelation between multiple XR frames (PDU-sets) may result in more efficient handling of XR traffic and scheduling. In order to optimize XR traffic transmission/reception between the WTRU and network, from the RAN perspective, the following (a) - (g) XR traffic characteristics, QoS metrics and application layer attributes may aid handling of RAN awareness: (a). PDU set level QoS metrics (delay budget, packet error rate, priority/importance). (b). PDU set boundary (the first/last packet in a PDU set), (c). PDU set size (e.g., payload sizes of all PDUs in PDU set, number of PDUs in a PDU set), (d). Periodicity, (e). Statistics characteristics of jitter, e.g., jitter range, (f). Intra/inter PDU sets dependency/synchronization. (g). Content of PDU set (e.g., number of frames by type, e.g., number of I-frames/P-frames/B-frames).

[0092] Size of data (e.g., size of frame and/or PDU and/or PDU-set and/or group of PDU-sets). The size of data may include features such as: (a) A PDU-set may include one more PDUs. (b) A PDU-set may include PDUs corresponding to only one type of frame (e.g., I-frame) or PDUs consisting corresponding to different types of frames (I-frames, P-frames, B-frames, etc.), (c) The size of the PDU-set may be variable from one PDU-set to another, (d) The WTRU may receive indications from the application/higher layers about the size of the PDU-set. In one example, the indication may come in the packet header of the first packet/PDU in the PDU-set. (e) The WTRU may receive indications from the application that the WTRU may use to infer the size of the PDU- set. In an example, the WTRU may receive indications about the first and the last packet in the PDU-set, which may be indicated in the headers of the first and the last packet for example, (f) The WTRU may receive size information on a more granular level. In an example, the WTRU may receive indications from the application about the typical size of different frames (e.g., I- frame, P-frame, B-frame). The first/last packet in the PDU-set may contain information indicating its type (e.g., corresponding to an I-frame or P-frame) and that it's the first/last packet of the PDU- set. Based on this information, the WTRU may be able to estimate the size of the PDU-set. (g) In an encoding scheme where different types of frames are encoded into different traffic streams (e.g., GOP -based whereby a single video frame is either an 1-frame or P-frame), the WTRU may receive indication linking the data flow to the frame type only once at the start of the session. In an example, the indication from the application to the WTRU may be bit-type, where "0" may correspond to a data flow with I-frames while " 1 " may corresponding to a data flow with P-frames. (h) The WTRU may receive information about the size of the PDU-set on a PDU-set basis and/or on a per-flow basis (e.g., in the GOP -based encoding scheme). This exchange may happen at the start of the XR session. The WTRU may receive regular updates throughout the XR session periodically or only if there is a change in the information (e.g., change in size of PDU-set). (j) The WTRU may receive information from the application/higher layers on multiple PDU-sets (i.e., granularity of group of PDU-sets). The application may group PDU-sets based on similarities between individual PDU-sets (e.g., same size, type, etc.).

[0093] Latency of data (e.g., latency of frame and/or PDU and/or PDU-set and/or group of PDU- sets): There may be different latency requirements associated with different types of frames. As a result of the possible variance in per-frame Packet Delay Budget (PDB) requirements, the PDU- Set Delay Budget (PSDB) may be different from one PDU-set to another PDU-set and from one group of PDU-sets to another group of PDU-sets.

[0094] There may be implicit or explicit indication of delay budgets per unit of data. In an example, the WTRU may explicitly receive in the header of the first packet of each PDU-set the PSDB of the PDU-set. (i) In an example, the WTRU may receive per-frame delay budget requirements from the application such that on reception of a PDU-set containing only 1-frames, the WTRU can determine the PSDB of the PDU-set. (ii) In another example, the WTRU may receive the PSDB of one PDU-set and assume that the PSDB of the following PDU-sets is the same (unless otherwise indicated).

[0095] The WTRU may receive from the application default values for the latency budget for different units of data (e.g., frame basis and/or PDU basis and/or PDU-set basis and/or group of PDU-set basis) such that in the absence of any (explicit or implicit) indication from the application, the WTRU may use the default values.

[0096] Importance of data (e.g., importance of frame and/or PDU and/or PDU-set and/or group of PDU-sets):

(a) Importance of data may be indicated to the WTRU from the application on different data-unit granularities, i.e., importance on a per-frame basis and/or per-PDU basis and/or per-PDU-set basis and/or per-group of PDU-sets basis, etc. (b) Indication of importance may be indicated for every data unit or it may be indicated for a first data unit and no indication is sent for the following data units until/unless there is a change in the importance, (c) Indication of importance may be as simple as a bit-wise binary indication or a flag indicating if the data is important enough to necessitate a special treatment: In an example, the XR application in the WTRU may flag a group of PDU-sets as important such that the WTRU may determine that transitioning to the RRC Connected state may be required to have better access to resource grants for a fast and reliable (e.g., lower MCS) transmission of the group of PDU-sets. (d) Indication of importance may be indicated through a table mapping different QoS levels in the legacy QoS framework to different important levels. In an example, the four most important QoS levels from the QoS framework may be flagged as important such that the WTRU may determine that any data mapped to radio bearers with the corresponding QoS flows from the four most important QoS levels may need to be sent from the RRC Connected state. Any data mapped to radio bearers with QoS flows from the remaining QoS levels may be sent in low power states, (e) Indication of importance may override QoS levels from the traditional QoS framework in some cases (e.g., if the data in the buffer is about to expire).

Methods for transmitting information to assist with operation in low-power state

[0097] The WTRU may send to network the information, possibly associated with XR actions, based on one or more of the following triggering events (a)-(e) as follows: (a) During connectivity/session establishment and/or (re)configuration. For example, during RRC connection, PDU session, application session establishment and/or (re)configuration. (b) When changing/updating XR actions. For example, when new XR actions and/or releasing XR actions, (c) When receiving higher layer/application information. For example, when receiving an indication (e.g., from application function hosted in WTRU or in network) indicating change in XR actions, forwarding configurations, etc. (d) When detecting change in measurements and movements. For example, when the RSRP, RSRQ, RSSI measurements of the signals, channels, radio links, carriers, etc., possibly associated with the one or more XR actions, are above/below threshold values. For example, when pose/positioning measurements (e.g., location information, pose in degrees of freedom) are above/below pose threshold values, (e) When detecting change in time/timing attributes. For example, WTRU may send information periodically or when a timer associated with sending of assistance information is set and/or expires.

[0098] WTRU sends higher/application-layer information to the network (NW)/gNB as follows: (a) The WTRU may send assistance information on higher/application-layer information to NW/gNB. This information may include any parameters from the application that may assist the NW/gNB in its scheduling task for the WTRU. Examples include: (i) Information about the traffic, (for e.g., information like packet size or expected arrival of PDUs or a group/cluster/burst of PDUs). (ii) expected periodicity of traffic, (iii) average expected jitter of traffic, etc. (iv) e.g., one or multiple threshold(s) associated to the XR experience/XR application that may require the triggering of a different resource grant allocation/configuration WTRU. (b) Any of the parameters above (e.g., jitter, data size, periodicity, etc.) may be transmitted by the WTRU in any of the following granularity: Per-frame basis and/or per-PDU basis and/or per-PDU-set basis and/or per-group of PDU-sets basis, etc.

[0099] WTRU sends other requests/information to NW/gNB:

In one example: (a) Request for UL grant (e.g., Configured Grant - Small Data Transmission (CG- SDT), Random Access Small Data Transmissions (RA-SDT), Dynamic Grant (DG) grant, or CG grant), (i) In an example, a WTRU may use the allocated CG-SDT grant to send some data in the UL. In the event the WTRU may still have some remaining data to send, the WTRU may send a request for an UL grant to the NW to fit in the remaining data, (ii) In another example, the WTRU may send a status report / buffer status report (SR/BSR) to the NW when it has more payload to transmit that can be accommodated with its current configurations (e.g., CG-SDT). [0100] In another example: (b) Request to transition to RRC Connected state which may include: (i) A simple request to transition to RRC Connected state or (ii) A request to transition to RRC Connected state accompanied by additional information (e.g., duration to remain in RRC Connected state) based on knowledge of XR traffic from the application.

[0101] In another example: (c) Request to remain in RRC Connected state which may include: (i) A simple request to remain in RRC Connected state or (ii) A request to remain in RRC Connected state accompanied by additional information (e.g., duration to remain in RRC Connected state) based on knowledge of XR traffic from the application.

[0102] In another example: (d) Request to transition to a low power state (e.g., RRC Inactive state) which may include: (i) A simple request to transition to a low power state (e.g., RRC Inactive state) or (ii) A request to transition to a low power state accompanied by additional information (e.g., duration to remain in low power state) based on knowledge of XR traffic from the application.

[0103] In another example: (e) Request to remain in a low power state (e.g., RRC Inactive state) (i) A simple request to remain in a low power state (e.g., RRC Inactive state) or (ii) A request to remain in a low power state accompanied by additional information (e.g., duration to remain in low power state) based on knowledge of XR traffic from the application.

[0104] In another example: (f) Indications to network on the assessment result from determination of the data that may be sent in a low power state, (i) In an example, instead of sending a request to transition/remain in an RRC state, the WTRU may send the results from its assessment based on traffic information from the XR application, leaving it to the NW to determine whether the WTRU should be transitioned to an RRC state different to its current RRC state, (ii) In this solution, the WTRU may have shared its capabilities information in an initial exchange with the NW. In the event the WTRU may be a different class/type WTRU, the NW may already be aware that operation in a low-power state needs to be prioritized for this class/type of WTRU. (iii) In one solution, the WTRU may send an indication (e.g., UCI, BSR, other MAC CE, other new signaling) to the NW on the result of the assessment whereby the WTRU may indicate information about the traffic in its buffer (e.g., number of frames, frame type, frame size, number of transmission cycles/slots/occasions that the WTRU anticipates it will take to transmit the payload in the UL, etc.)

[0105] In another example: (g) Indications from XR application, (i) In an example, instead of sending the assessment results, the WTRU may simply send the raw information on the traffic characteristics sent by the application, leaving it to the NW to assess whether/when an RRC state transition is required/warranted/preferred.

[0106] In another example: (h) Confirmation of receipt of grant. In response to any grant from the NW (e.g., CG-SDT or DG), the WTRU may send a confirmation of receipt of the grant to the NW.

[0107] In another example: (j) Data to the NW. In an example, the WTRU may send the data stream with the P-frames in a low power state (e.g., RRC Inactive state). Methods for receiving information to assist with operation in low-power state

[0108] In one family of solutions, there may be periodic allocations of resources and/or any configurations information to the WTRU. In another family of solutions, there may be dynamic allocations of resources and/or any configuration information to the WTRU. To enable these solutions, the WTRU may receive any of the following.

[0109] The WTRU may receive higher/application-layer information about the XR experience. In one example, (a)The WTRU may receive higher/application-layer information about the XR traffic characteristics, application-layer parameters, QoS metrics and/or any information that may be relevant/beneficial for the XR action. Some examples include: (i) Information about the XR traffic characteristics, (for e.g., size of PDU-set, expected arrival time of PDUs or a group/cluster/burst of PDUs, etc.), (ii) expected periodicity of traffic, (iii) average expected jitter of traffic, etc. (iv) e.g., one or multiple threshold(s) associated with the XR experience/XR application that may require the triggering of a different resource grant allocation/configuration. (v) Information about any traffic parameters (e.g., periodicity, size of data, jitter, etc., may be received by the WTRU in any of the following granularity: Per-frame basis and/or per-PDU basis and/or per-PDU-set basis and/or per-group of PDU-sets basis, etc.

[0110] The WTRU may receive assistance information from NW to enable/facilitate the XR experience, information in a low-power state which may include any of the following (a)-(f) below.

[OHl] Assistance information from NW: (a) Configuration (e.g., in RRC) information, (i). WTRU may receive configuration information (e.g., CG-SDT information in RRC Release with Suspend message) from the NW/gNB for operating in a low-power state (e.g., in RRC inactive state or any state other than Connected state). In an example, the configuration information may include information on the CG-SDT config (e.g., periodicity, offset, validity timer to make use of grant within CG-SDT cycle), (ii). The configuration information may include one or more thresholds with regards to operating in a low power state. In an example, the WTRU may receive a threshold corresponding to the maximum size of the payload that can be accommodated in the CG-SDT grant.

[0112] Assistance information from NW: b. Release message, (i) In an example, the WTRU may receive an RRC Release message from NW to transition into RRC Connected state, (ii) In another example, the WTRU may receive an RRC Release with Suspend message from the NW for operating and/or continue to operate in a low power state (e.g., RRC Inactive state).

[0113] Assistance information from NW: (c) UL grant: (i) In an example, the WTRU may receive UL grants (e.g., RA-SDT, CG-SDT, DG, etc.) from the network that the WTRU may use to transmit data in a low-power state, (ii) In a solution, the WTRU may fit the maximum amount of its payload into the CG-SDT grant. In the event the WTRU has more data that can be accommodated in the CG-SDT grant, the WTRU may receive an UL grant (which may be the result of a B SR that the WTRU sent to the NW) to send in the remaining payload.

[0114] Assistance information from NW : (d) One or more pre-configured set of resource grants (e.g., multiple CG-SDT grants with different periodicities and/or offsets and/or resource grant size) out of which one may be activated. The sets of pre-configured resource grants may have been approved/pre-approved by NW following input from the WTRU (e.g., on the expected traffic for the WTRU). The initial selection of an activated resource grant may be based on the following: (i) In an exemplary solution, the WTRU may receive resource grant activated by gNB in the beginning of the XR session based on the knowledge of the type/class of WTRU and/or type or traffic (e.g., volume, periodicity), (ii) In another exemplary solution, the WTRU may receive resource grant activated by gNB in the beginning of the XR session based on the historical knowledge of the resource grants activated in previous time periods for the same type of XR experience, (iii) In another exemplary solution, the WTRU may receive resource grant activated by gNB in the beginning of the XR session based on indications from the WTRU on traffic information (e.g., the traffic periodicity, volume, etc.).

[0115] Assistance information from NW: (e) Thresholds that may trigger a change in the resource grant allocation. There may be one or more thresholds, associated with each parameter described in the paragraphs above addressing Parameters to Determine Operation in Low-Power State. E.g., threshold corresponding to variable-size payloads for SDT, delay budget thresholds associated with different CG-SDT resources, etc.

[0116] Assistance information from NW: (f) Configuration for operating in the Inactive state (e.g., in RRCReleasewithSuspend message) for operating in the Inactive state, e.g., CG-SDT configurations, different thresholds corresponding to payload size, remaining time, PDU Set Importance (PSI).

[0117] In an exemplary solution, the WTRU may receive indication of an event from application and more details about the 'event' (e.g., duration of event), (a) An 'event' may, for e.g., result in a change in the current mode of operation (e.g., change in resource grant allocation, change in periodicity of configured grant, application of offset to resource grant allocation, etc.), (b) Example of an 'event' may include an upcoming increase in the ratio of I-frames:P-frames as a result of a fast change in scenery. As a result of I-frames being generally larger in size compared to P-frames, this may necessitate a change in resource grant allocation. Definition of 'event' and examples of when an 'event' may be detected have been listed in the XR Definitions subsection. [0118] In an exemplary solution, the WTRU may receive a resource grant activation from gNB, e.g., following a request to gNB to change resource allocation configuration. Change in resource allocation configuration could either mean selection of a different resource allocation configuration (e.g., different CG-SDT configuration) or application of an offset to an ongoing active one.

[0119] In one solution, the WTRU may receive a resource grant confirmation, e.g., at the start of an XR session and/or throughout the XR session and/or following any request for a change in the resource grant configuration (e.g., following a request for a change in CG-SDT configuration sent to the network).

[0120] In one solution, the WTRU may receive a message/indication from gNB that its request for a change in resource grant allocation (e.g., change from one CG-SDT configuration to another CG-SDT configuration) may not have been granted, (a) The WTRU may receive a message from the gNB indicating that the change in resource grant allocation (e.g., change in CG-SDT) may not be possible in the next few cycles but may be possible a few cycles in the future, (b) Alternatively, the WTRU may instead receive a request from the gNB to transition to the RRC Connected state to send its UL data.

[0121] In an exemplary solution, the WTRU may receive an explicit indication from gNB to revert to its default/originally activated mode of resource grant allocation (e.g., in the case the WTRU is configured with multiple CG-SDT configurations out of which one configuration is the designated default configuration). The gNB may send this indication to the WTRU based on observation of a return to normal of traffic conditions/requirements based on, for e.g., restoration of QoE as indicated by XR application service.

[0122] WTRU may receive data from application, (a) The WTRU may receive one or more PDU-sets, which may include I-frames, P-frames, B-frames, etc. (b) Time of arrival of data at WTRU from application may be measured by WTRU and arrival outside of an expected time window may trigger an 'event', which may lead to a request to alter resource allocation configuration.

[0123] In one solution, the WTRU may receive information regarding which set of time and/or frequency resources the WTRU may transmit in. The WTRU may receive the time domain resource information via DCI. This may provide information regarding delay from DCI to PUSCH slot and length of consecutive symbols allocated for PUSCH. The WTRU may be provided with an offset in time and/or frequency resources. Different CG-SDT resources may be associated with different offsets. [0124] In one solution, the issued uplink grants (configured grant-type periodic grant allocation and/or dynamic grant allocation) may have an associated timer to specify a validity period over which the grant is eligible. E.g., the WTRU may have a time window within each CG-SDT slot where it may be expected to send the UL payload. If the WTRU has missed the window, the CG- SDT grant may no longer be valid. As such, the WTRU may have the following options:

(a) WTRU may need to wait for the next CG-SDT transmission slot to transmit the uplink payload.

(b) WTRU may need to transition to RRC connected state or another low-power state where monitoring of DCI may be more frequent (as compared to inactive state).

Methods for enabling operation in low-power state

[0125] WTRU determines the data that may be sent in low-power state

[0126] The WTRU may determine the total volume and timing of data that can be sent in Inactive state based on application layer information such as: (a) Number of I-frame v/s P-frame, (b) Associated per-frame delay budget, (c) Importance of data unit, etc. and (d) Configuration information from the NW/gNB.

[0127] In an exemplary solution, the WTRU may have received configuration info from the NW/gNB including data volume thresholds such that the WTRU has been indicated by the NW that it may be possible to transmit UL payload volume lower than that data volume threshold while remaining in a low-power state (e.g., transmission in RRC Inactive state using CG-SDT resources). While in a low power state (e.g., RRC inactive state), when the WTRU receives data in its buffer (from the application), the WTRU assesses the volume of the data received from the application (e.g., number/types of frames, frame size, etc.) against the data volume threshold from the NW. The data volume threshold from the gNB may correspond to the UL payload volume within one or multiple CG-SDT slots/transmission cycles. Examples (l)-(d) may be as follows: (a) In one solution, the WTRU may use the CG-SDT grants to send the UL data while remaining in Inactive state if the volume of data in its buffer is less than the data volume threshold, (b) In one solution, the WTRU may determine that the volume of data of the smaller frames (e.g., P- frames) is below the data volume threshold from the gNB such that the WTRU may be able to only send the smaller frames (P-frames) while in a low power state (e.g., Inactive state), (c) In one solution, the WTRU may determine that segmenting/splitting the UL data in its buffer into multiple CG-SDT slots/transmissions cycles satisfies the threshold requirement for low-power state transmission. The WTRU may split its data according to the one or multiple data volume thresholds and send it across one or multiple CG-SDT slots/transmission cycles, (d) In one solution, the WTRU may send an indication to the NW of a higher incoming volume of data for the next x number of cycles/transmission slots. In response, the NW may increase the size of the UL grant in the x number of CG-SDT cycle(s)/transmission slot(s) and/or the NW may increase the number of UL grant in the x number of CG-SDT cycle(s)/transmission slot(s) (e.g., from one UL grant in one cycle/transmission slot to two UL grants in one cycle/transmission slot). In the latter scenario, the two UL grants within one cycle/transmission slot may be consecutive or spaced out from each other (with slots in between).

[0128] The data volume threshold received from the gNB may be on a per-radio bearer basis, or it may be a total data volume threshold based on the aggregation of the data in all the radio bearers at the WTRU and/or the total data volume threshold based on the aggregation of the data in all the radio bearers where a low-power state resource configuration (e.g., CG-SDT) is enabled.

[0129] In an exemplary solution, the WTRU may have received configuration info from the NW/gNB including delay budget thresholds such that the WTRU has been indicated by the NW that it may be possible to transmit UL payload data whose delay budget is within the threshold bounds while remaining in a low-power state (e.g., transmission in RRC Inactive state using CG- SDT resources). While in a low power state (e.g., RRC inactive state), when the WTRU receives data in its buffer (from the application), the WTRU assesses the delay budget of the data received from the application (e.g., PDB, PSDB etc.) against the delay budget threshold from the NW. Examples solutions include: (a) In one solution, the WTRU may have received (e.g., from the application) the PSDB of the PDU-sets in its buffer such that the WTRU may assess whether it may be able to transmit the PDU-sets within their PSDB requirements while remaining and/or transitioning to a low power state (e.g., RRC Inactive state) or it needs to remain/transition to the RRC Connected state to successfully transmit the PDU-sets in its buffer within their PSDB requirements, (b) In one solution, the WTRU may be aware that in the absence of any other indication (explicit or implicit), I-frames may be more important than P-frames. As such, the WTRU may remain in the RRC connected state or transition to the RRC connected state to send the 1-frames since the WTRU may determine that it may have access to larger and/or more frequent UL grants while in the RRC Connected state to meet the PSDB requirements for the 1-frames. The WTRU may subsequently transition to a low power state (e.g., RRC Inactive state) to transmit the remaining P-frames.

[0130] In an exemplary solution, the WTRU may have received configuration info from the NW/gNB including quality/priority metrics/thresholds such that the WTRU has been indicated by the NW that it may be possible to transmit UL payload data whose data importance exceeds the quality/priority metrics/thresholds while remaining in a low-power state (e.g., transmission in RRC Inactive state using CG-SDT resources). While in a low power state (e.g., RRC inactive state), when the WTRU receives data in its buffer (from the application), the WTRU assesses the importance/priority level of the data received from the application (e.g., flag indicating important data or priority level corresponding to importance of data) against the quality/priority metrics/threshold from the NW. (a) In one solution, each data unit (e.g., PDU-set) may be sent to the WTRU from the application with an importance/priority level. The WTRU may assess the importance/priority level of the PDU-set in its buffer against the threshold from the NW such that if the importance/priority level of the PDU-set in its buffer exceeds the threshold, the WTRU may be able to transmit the PDU-set while remaining in a low power state (e.g., RRC Inactive state), (b) In one solution, each data unit (e.g., group of PDU-sets) may be sent to the WTRU from the application with an importance/priority level. The WTRU may assess the importance/priority level of the group of PDU-sets in its buffer against the threshold from the NW such that if the importance/priority level of the group of PDU-sets in its buffer exceeds the threshold, the WTRU may determine that transitioning to the RRC Connected state may provide it with more resources (e.g., larger and more frequent grants) to successfully transmit the group of PDU-sets.

Restricting XR traffic transmission via SDT

[0131] In some solutions, a WTRU may be restricted to transmitting data (e.g. XR PDUs, PDU- sets) via small data transmission (i.e. data transmission prior to transmission to RRC Connected state e.g. via transmission of an RRCResumeComplete message) only under certain circumstances.

[0132] Restriction of XR traffic with certain data/WTRU/transmission characteristics

[0133] In one solution, a WTRU transmitting XR traffic (e.g. a PDU-set), may be restricted to transmitting (via SDT) data with one or more of the following characteristics: (a) Whether the data is associated with XR traffic or an ongoing XR session, (b) The data type and/or content of the PDU: For example, whether the PDU contains an I-frame, P-frame, or pose information, (c) The PDU set size: (i) For example, the WTRU may only transmit via SDT one or more PDUs belonging to a set if the overall number of PDUs belonging to a set is less than a threshold, (ii) In another example, the WTRU may only transmit via SDT one or more PDUs belonging to a set if the total data volume of a set is below a threshold, (d) The location of the PDU within the PDU set: (i) For example, the WTRU may only transit the final N PDUs via small data transmission, (ii) In another example, the WTRU may only transmit the first K PDUs via small data transmission, (e) The remaining duration of the PDU set validity: (i) For example, the WTRU may only transmit XR traffic via SDT if the remaining validity of one or more PDUs within a PDU set is about to expire (e.g. the time of expiry is within a threshold), (f) QoS characteristics: (i) For example, the WTRU may only transmit data via SDT if the data possesses certain QoS characteristics (e.g., latency, reliability, or 5QI profile), (g) Whether the transmission is a retransmission or initial transmission; (h)The radio bearer of the UL traffic, (j) Whether the PDU requires segmentation: (i) For example, a WTRU may only transmit an XR packet via SDT if the packet does not require segmentation (i.e., transmission over multiple small data occasions), (ii) In another example, a WTRU may only transmit an XR packet via SDT if it requires less than X segmentations.

[0134] In another solution, the WTRU may be restricted to transmit XR traffic via SDT based on the transmission type and/or transmission characteristics used for small data transmission. For example, the XR device may only transmit traffic subject to one or more of the following: (a). The method of transmission: For example, whether the data is transmitted via Random Access Channel (RACH) messaging (e.g. MsgA, Msg3, or Msg5) or configured grant, (b). A configured grant characteristic(s): For example, if the periodicity of the configured grant is not suitable for XR traffic (e.g. the time between successive transmission opportunities is too large) then the WTRU may not use SDT. (c) The grant size, (d) The allowed QoS profile of the grant, (e) The time until transmission opportunity: (i) For example, upon arrival of a PDU for UL transmission, the WTRU may only use SDT if the next small data transmission opportunity is less than X resources away, (ii) In another example, upon arrival of a PDU for UL transmission, the WTRU may only use SDT if the next small data transmission opportunity is less than X resources (e.g., symbols, subframes, frames, milliseconds, microseconds, frequency bands) away from the next RACH opportunity (e.g., RACH occasion), (iii) In another example, upon arrival of a PDU for UL transmission, the WTRU may only use SDT if the next small data transmission opportunity is less than X resources (e.g., symbols, subframes, frames, milliseconds, microseconds, frequency bands) away from the next RACH opportunity (e.g., RACH occasion) plus some additional time Y (e.g., which may represent the time until a successful connection establishment).

[0135] In another solution, the WTRU may be restricted to transmit XR traffic based on the WTRU characteristics, for example, one or more of: (a) The RSRP of the current camped cell; For example, the WTRU may only transmit XR traffic if the RSRP of the current camped cell is above a threshold. This threshold may be the same or different from a RSRP threshold necessary to perform SDT. This threshold may be the same or different from an RSRP threshold used to determine whether CG may be used for SDT transmission, (b) Measurement variation. For example, based on the RSRP variation. As an example, measurement criterion for WTRU with low mobility may be fulfilled when: (SrxlevRef - Srxlev) < SSearchDeltaP, Where: Srxlev = current Srxlev value of the serving cell (dB), and SrxlevRef = reference Srxlev value of the serving cell (dB). The conditions for setting the Sexlevref may be based on time criteria, for example if the low mobility criteria has not been met for TSearchDeltaP. (c) Relaxed monitoring status. For example, the WTRU may determine it is in a low-mobility state based on activation of relaxed monitoring. For example, a combination of the above criteria for low mobility, plus another criteria based on WTRU not being at cell edge. Measurement criterion for WTRU not at cell edge may be fulfilled when: Srxlev > SSearchThresholdP, and, Squal > SSearchThresholdQ, if SSearchThresholdQ is configured, (d) WTRU positioning information and/or WTRU position within a cell: (i) For example, the WTRU may only transmit XR traffic if the WTRU is at "cell center". Alternatively, the WTRU may only transmit XR PDUs if the WTRU is within a distance threshold Z from the gNB.

[0136] In another solution, the WTRU may be restricted to transmit XR traffic based on a time period, for example, one or more of the following: (a) Time since last connection: For example, the WTRU may only transmit XR traffic if it has been less that X time units (e.g. frames, milliseconds, seconds, minutes, hours) since the WTRU was last in a connected state, (b) Time since last small data transmission carrying XR traffic: For example, the WTRU may only transmit XR traffic if it has been less that X time units (e.g. frames, milliseconds, seconds, minutes, hours) since the WTRU last sent an XR PDU via small data transmission.

[0137] In another solution, the WTRU may be restricted to transmit XR traffic based on WTRU mobility and/or cell (re)selection characteristics. For example, one or more of the following: (a) Whether the gNB receiving the small data PDU is the same as the one which released the WTRU: For example, the WTRU may be restricted to transmit XR via SDT only if the WTRU is transmitting the data to the same gNB that it was released from (e.g., the same gNB that the WTRU received the RRCReleasewithSuspend message). In another solution, the WTRU may only transmit XR via SDT if the WTRU is transmitting to a gNB within the same RNA as the gNB it received the RRCReleasewithSuspend message, (b) Number of cell (re)selections: For example, the WTRU may only transmit XR traffic based on one or more of: (1) If the WTRU has not performed a cell (re)selection since it has received an RRCReleasewithSuspend message; (2) If the WTRU has performed less than X cell reselections since it has received an RRCReleasewithSuspend message, (c) Mobility-state estimation status: For example, the WTRU may only transmit XR traffic if the WTRU is not classified as 'high-mobility', (d) Mobility history record.

[0138] In another solution the WTRU may only transmit XR traffic via SDT if it is classified as 'prioritized'. An XR PDU/PDU-set may be classified as prioritized, for example, if it fulfills one or more conditions such as those listed herein, or based on a higher-layer designation (e.g. from the application itself). A PDU may be distinguished as prioritized, for example, by a flag bit (e.g. within the message header), a 5QI profile, or if it is allocated to one or more radio bearers.

[0139] Configuration of Restrictions for XR transmission via SDT

[0140] In one solution, the WTRU may apply one or more restrictions based on configuration (e.g., via RRC configuration). One or more methods may be used to configure a restriction based on, for example, potential data/WTRU/transmission characteristics listed within this section. For example, the restrictions may be configured via one or more of the following methods (a)-(e): [0141] (a) An LCP mapping restriction: For example, RRC may configure a new mapping restriction such as allowedXR-SDT which sets whether small data transmission may be used for XR PDU transmission. When a new small data transmission is performed, the MAC entity may only select a logical channel configured with allowedXR-SDT.

[0142] (b) Explicit configuration: For example, the WTRU may receive an explicit configuration which enables/disables XR transmission based on the configuration. For example, the WTRU may receive a configuration parameter Ifirame with configurations 'enabled' or 'disabled'. If the Iframe parameter is configured as enabled, the the WTRU may transmit via SDT all PDUs containing Iframe data. Alternatively, if the parameter is listed as 'disabled' then the WTRU may not transmit via SDT a PDU containing Iframe data.

[0143] (c) Thresholds: For example, the WTRU may be configured with one or more thresholds, for example, XR-SDT-RSRP. Upon arrival of an XR packet for small data transmission, the WTRU may evaluate whether the threshold (e.g. whether the value has met, exceeded or fallen below the threshold), and if the threshold is satisfied the WTRU may perform XR transmission via SDT.

[0144] (d) Timers: For example, whether SDT may be used for XR traffic may depend on whether a timer with a configured duration is running. (1) For example, upon reception of an RRCReleasewithSuspend message or transmission of small data, the WTRU may start a timer. (2) While the timer is running, the WTRU may perform SDT. (3) Upon timer expiry, the WTRU may not perform SDT. (4) The WTRU may stop/restart the timer upon transition to connected state/mode (e.g. upon transmission of an RRCResumeComplete message).

[0145] (e) Counters: For example, whether SDT may be used for XR traffic may depend on whether a counter (e.g. allowedNumberofCellReselections) has exceeded a configured value. (1) For example, upon reception of of an RRCReleasewithSuspend message or transmission of small data, the WTRU may start maintaining a counter. (2) While the counter is less than the configured maximum, the WTRU may perform SDT. (3) One the counter value has met and/or exceeded the maximum value, the WTRU may not perform SDT. (4) The WTRU may reset the counter upon transition to connected state/mode (e.g., upon transmission of an RRCResumeComplete message). [0146] In one solution, the WTRU may receive one or more restriction configuration(s), for example, via one or more of the following methods (a)-(d). (a) Upon WTRU release to RRC INACTIVE state. For example, the WTRU may receive a restriction configuration within an RRCReleasewithSuspend message, (b) While in connected state/mode: For example, the WTRU may be configured with XR transmission restriction for small data while in RRC CONNECTED state. Upon release the WTRU may maintain this configuration for small data transmission, (c) via system information, (d) via paging. For example, the paging message may include an indication to enable/disable XR transmission via SDT. In another paging example, the paging message may enable/disable one or more restrictions. For example, the paging message may contain an index (pointing to a specific restriction) and an enable/disable bit.

[0147] In one example, the WTRU may be configured with an IE XR-SDT transmission, wherein the WTRU will be configured with one or more restrictions (e.g., timer/counter duration, thresholds, and explicit enable/disable configurations) associated with one or more WTRU/data/transmission characteristics. Upon arrival of XR PDU for UL transmission via SDT, the WTRU will evaluate whether the PDU satisfies the relevant restrictions. If the restrictions are satisfied the WTRU may send the XR PDU via small data transmission. If the restrictions are not satisfied, the WTRU may transition to connected state/mode e.g., via random access.

[0148] The WTRU may receive a delta configuration for the restriction configuration, wherein the WTRU will apply the values received within a configuration to an existing (or previously received) configuration, or a default set of values. The WTRU may determine the new configuration is a delta configuration based on an explicit indication (e.g., a flag bit present within the configuration).

[0149] Upon state transition (e.g., upon reception of an RRCResume, RRCSetup, RRCRelease message), wherein the WTRU will no longer be able to perform SDT, the WTRU may maintain (or alternatively delete) the restriction configuration.

[0150] If configured, the WTRU may apply an XR/SDT restriction semi-statically, or unless otherwise indicated. In another solution, the application of a restriction configuration may be conditional. For example, the WTRU may apply the restriction subject to a pre-configured duration, or based on an enable/disable indication.

[0151] WTRU assistance information to aid in configuration of a restriction

[0152] In one solution, the WTRU may provide assistance information to the network to configure restrictions, thresholds, timers/counters or other restrictions described herein. Transmission of assistance information may occur, for example, upon release to inactive state, periodically, or based on network request (e.g. upon reception of paging). The WTRU may include one or more of the following information fields in the WTRU assistance information: (a) Whether the WTRU is an XR device, (b) The traffic profile of the device or characteristics of UL data transmission (e.g., time/frequency/expected data volume), (c) Currently applied restrictions, (d) The power and/or battery status of the device, (e) The device location (e.g., measurements associated with PRS, or the WTRU GNSS location), (f) Measurements (e.g., the measurements to the current camped cell), (g) Cell (re)selection information (e.g., the number of cell (re)selections since connection release, or since the last small data transmission), (h) Status of all currently running timers/counters relevant to XR restrictions.

[0153] The WTRU may report assistance information, for example, via RRC signaling or MAC CE. A report may be sent, for example: during the Random Access procedure (via msgA, msg3, or msg5); via dedicated resources (e.g. stored grants, configured grant occasions, or periodically reserved resources for WTRU reporting) or using previously provided resources (e.g., provided in a RRCRelease or RRCReleasewithSuspend).

Methods for Determining that a Currently Allocated Grant is Not Sufficient

[0154] In one solution, the WTRU may determine that a currently allocated grant is not sufficient to meet a QoS/QoE based on a set of criteria associated to XR data traffic characteristics, and then transmit an indication to the network.

[0155] The currently allocated grant, e.g., Y, may be the result of any one or more of the following: (a) One or more CG-SDT configuration(s). In one example, the size of the CG-SDT grant may include the size of one CG-SDT grant from one CG-SDT configuration. In another example, the size of the CG-SDT grant may include the sum of the size of more than one CG-SDT grants from the one CG-SDT configuration. In another example, the WTRU may be configured with multiple CG-SDT configurations that may be concurrently activated. The size of the CG- SDT grant may include the sum of the size of more than one CG-SDT grant(s) from the multiple CG-SDT configurations, (b) One or more CG configuration(s). In one example, the size of the CG grant may consist of the size of one CG grant from one CG configuration. In another example, the size of the CG grant may include the sum of the size of more than one CG grants from the one CG configuration. In another example, the WTRU may be configured with multiple CG configurations that may be concurrently activated. The size of the CG grant may include the sum of the size of more than one CG grant(s) from the multiple CG configurations, (c) One or more DG grants. In one example, the currently allocated grant may be one or more DG grants, received as a result of one or more BSR (buffer status report) sent by the WTRU to the network. The size of the allocated grant may be the size of one DG grant or the sum of the size of multiple allocated DG grants, (d) Any one or more of the above, such as a combination of CG and/or DG grants and/or CG-SDT grants. In one example, the currently allocated grant may be the sum of a CG grant from one activated CG configuration and a DG grant. value of X.

[0156] The process of determining that a currently allocated CG is not sufficient may include the WTRU doing the data volume calculation to determine the amount of data in its buffer(s), e.g., MAC buffer and/or PDCP buffer and/or RLC buffer, etc. denoted as X in this example, and comparing the size of the allocated grant against the amount of data. In another example, the WTRU may have knowledge of the upcoming data (e.g., within a time window) which the WTRU may include in the value of X. In one example, the WTRU may have knowledge of the upcoming data from the XR application. In another example, the WTRU may have knowledge of the upcoming data based on PDU set knowledge. In this example, the WTRU may receive a PDU set including one or more PDUs. The first one or more PDUs of the PDU set may carry information on the size of the PDU set. Such marking may have been added by the higher/application layers for example. Following reception of the first PDU of the PDU set, the WTRU may have knowledge of the upcoming PDUs of that PDU set (e.g., of the upcoming number of PDUs of the PDU set and/or the size of the entire PDU set, etc.).

[0157] In another example, the WTRU may determine that the currently allocated grant is not sufficient in one of more of the following scenarios. For example, if X > Y. For example, if X - Y > a threshold received by the WTRU from the network (e.g., as part of an initial configuration). [0158] Following the above determination, the WTRU may send a message/indication to the network (e.g., via UCI, MAC CE, BSR or any other messaging) to indicate any one or more of the following: That a currently allocate grant is not sufficient. That the sum of more than one currently allocated grant is not sufficient. The differential amount by which the one or more grant is not sufficient (e.g., the amount represented by X - Y). A request for additional grants (e.g., CG and/or CG-SDT and/or DG grants).

Methods for Determining that a Change in Resource Allocation is Needed

[0159] In one example, the WTRU may determine that a change in the amount of resources it has been allocated is not sufficient for a SDT and as a result, may request for a change in the configuration by sending a request to the network. In one example, the WTRU may request for a change in the CG-SDT configuration (e.g., larger sized CG-SDT grants, more frequent CG-SDT grants, etc.). In another example, the WTRU may request to be configured with more than one CG-SDT configuration that the WTRU may activate concurrently. In one example of this, the WTRU may only activate one CG-SDT configuration at a time. Only when determining that X > Y and/or X - Y > a threshold received by the WTRU from the network (e.g., as part of an initial configuration), the WTRU may activate the second CG-SDT configuration.

[0160] In another example of a needed resource allocation change, the WTRU may request for a change in the CG configuration (e.g., larger sized CG grants, more frequent CG grants, etc.) In another example, the WTRU may request to be configured with more than one CG configurations that the WTRU may activate concurrently. In one example of this, the WTRU may only activate one CG configuration at a time. Only when determining that X > Y and/or X - Y > a threshold received by the WTRU from the network (e.g., as part of an initial configuration), the WTRU may activate the second CG configuration.

[0161] If a change in resource allocation is determined to be needed, the WTRU may send a request to network following one or more of the following (a)-(d): (a) X > Y. (b) X - Y > a threshold, (c) The importance of data in WTRU buffer and/or upcoming data is larger than a threshold received by the WTRU from the network (e.g., as part of an initial configuration). E.g., if PDU Set Importance (PSI) > a threshold, (d) If remaining time < threshold received by the WTRU from the network (e.g., as part of an initial configuration). In one example of this, the remaining time = PSDB (PDU Set Delay Budget). In another example, the remaining time = PSDB - total amount of time data spent in WTRU buffer (e.g., any one or more of MAC and/or PDCP and/or RLC buffer and/or SDAP buffer) In another example, the remaining time is a function of the PSDB (PDU Set Delay Budget). In another example, the remaining time is a function of the PSDB - total amount of time data spent in WTRU buffer (e.g., any one or more of MAC and/or PDCP and/or RLC buffer and/or SDAP buffer)

[0162] If a change in resource allocation is determined to be needed, the Indication/request sent by WTRU to the network may carry any one or more of the following: (a) Change to one or more CG and/or CG-SDT configuration. In one example of this, the WTRU may request for larger CG- SDT grants within the one configured CG-SDT configuration. In another example, the WTRU may request for increased periodicity of the CG-SDT grants within the one configured CG-SDT configuration. In another example, the WTRU may request for an additional CG-SDT configuration that it may activate concurrently if/when required. In another example, the WTRU may request for larger CG grants within the one configured CG configuration. In another example, the WTRU may request for increased periodicity of the CG grants within the one configured CG configuration. In another example, the WTRU may request for an additional CG configuration that it may activate concurrently if/when required, (b) Whether the requested change is for a time period or indefinite (until further notice). In one example of this, the change may be for a time period, in which case, the WTRU may sent the time period for which it expects the change to last. For example, there may be an increase in the amount of data to be transmitted at a given time which may not be expected at a later time. As such, the WTRU may determine the time window for which the change in the CG and/or CG-SDT configuration may be needed as a result of the additional volume of data the WTRU expects to transmit at that time. In another example, the request for a change may not be accompanied with any time period/window information, in which case, the network may assume that the change in the CG-SDT and/or CG configuration is indefinite (or until a future indication from the WTRU is received).

Methods for PDCCH Monitoring in Low Power State

[0163] In one method for monitoring, the WTRU may receive configuration from the network, e.g., as part of initial configuration and/or following a request for a change in resource allocate (e.g., request for a change in CG-SDT and/or CG configuration(s)). In one example, each CG- SDT configuration and/or change thereof (e.g., change in grant size or grant periodicity) received from the network may be accompanied by the corresponding time/window for the WTRU to monitor PDCCH following the activation of the new and/or modified CG-SDT configuration. In another example, a CG-SDT configuration with a high grant periodicity (e.g., a grant every 10ms) may require the WTRU to monitor PDCCH in Inactive state at high periodicity (e.g., periodicity at least matching the grant periodicity).

[0164] In another method for monitoring, the WTRU may determine the time duration/window and/or monitoring frequency/instances to monitor for PDCCH (e.g., in Inactive state) based on any one or more of the following (a)-(d): (a) Configuration from network as described above, (b) Size of grant; e.g., size of CG-SDT grant in the one or more activated CG-SDT configuration(s). e.g., size of CG-SDT grant in the one or more CG-SDT configuration(s) that has/have been updated more recently, e.g., size of CG grant in the one or more activated CG configuration(s). e.g., size of CG grant in the one or more CG configuration(s) that has/have been updated more recently, (c) Periodicity of grant; e.g., periodicity of CG-SDT grant in the one or more activated CG-SDT configuration(s). e.g., periodicity of CG-SDT grant in the one or more CG-SDT configuration(s) that has/have been updated more recently, e.g., periodicity of CG grant in the one or more activated CG configuration(s). e.g., periodicity of CG grant in the one or more CG configuration(s) that has/have been updated more recently (d) Time Information; (1) E.g., delay budget, e.g., PSDB of PDU set in WTRU buffer. (2) E.g., remaining time = PSDB - total amount of time data spent in WTRU buffer (e.g., any one or more of MAC and/or PDCP and/or RLC buffer and/or SDAP buffer). (3) E.g., on a time element which may be a function of the delay budget and/or remaining time.

[0165] In another method for monitoring, the WTRU may send an indication to the network of its modified PDCCH monitoring behavior (e.g., modified time duration/window to monitor PDCCH in inactive state, modified frequency/instances for monitoring PDCCH in inactive state). [0166] In another method for monitoring, the WTRU may send a request to the network to be transitioned to the connected state.

[0167] In another method for monitoring, the WTRU may send one or more B SR to the network to request for DG grants.

[0168] In another method for monitoring, the WTRU may receive an indication from the network (e.g., in the new time window that the WTRU is monitoring PDCCH). Indication may include any one or more of the following Updated resource grant configuration; (1) E.g., if the WTRU receives an updated resource grant from the network (e.g., updated CG-SDT configuration with larger grants and/or DG resources) in the new monitoring time window from the network, the WTRU may use the grants to transmit data in inactive state. (2) If the WTRU receives a release message from the network to transition to RRC Connected state, the WTRU may transition to RRC Connected state to transmit the data/upcoming data in its buffer.

Example Realizations

[0169] Example Embodiment #1

[0170] In a first embodiment, an uplink solution may be used under the conditions of a variable PDU-set size and a deterministic small data transmission (SDT) when the WTRU in the RRC Inactive state. FIG. 2 depicts an example WTRU method 200 using the first embodiment conditions.

[0171] At step 205, the WTRU receives configuration information (e.g., in a RRCReleasewithSuspend message) for operating in the Inactive state. For example, the configuration info may include different thresholds corresponding to variable-size payloads to send data in the uplink in the Inactive state. At 210, the WTRU receives one or more PDU-sets to send in the uplink, which may include n I-frames and m P-frames. At 215, the WTRU determines the total volume and timing of data that can be sent in inactive state based on application layer information (e.g., number of I-frame v/s P-frame + associated per-frame PDB) and configuration info from step 205. [0172] At 220, the WTRU sends the smaller P-frames in the Inactive state as small data transmissions (SDT)s. At 225, the WTRU sends indication (e.g., BSR, new signaling) to network on information determined in step 215. Indication information may include: (a) Number of I- frames, frame-size, (b) Number of cycles/occasions WTRU expects UL payload to last.

[0173] At 230, if the WTRU receives a release message from the network to transition into the RRC Connected state, then the WTRU sends the larger frames (e.g., I-frames) in the RRC Connected state. At 235, if the WTRU receives an uplink grant, (e.g., RACH SDT, DG) from network, the WTRU sends 1-frames using the UL grant.

[0174] Example Embodiment #2

[0175] In a second embodiment, an uplink solution may be used under the conditions of a variable PDU-set size and a deterministic SDT when the WTRU in the RRC Connected state. FIG.

3 depicts an example WTRU method 300 using the second embodiment conditions.

[0176] At 305, A WTRU receives one or more PDU-set(s) to send in the uplink, which incudes n 1-frames and m P-frames. At 310, the WTRU determines the total volume and timing of data that can be sent in Inactive state based on application layer information (e.g., number of I-frame v/s P-frame + associated per-frame PDB). At 315 the WTRU sends the larger frames (e.g., I- frames) while the WTRU is in the RRC Connected state.

[0177] At 320 the WTRU sends a release request to the NW (such as a gNB base station (BS)) to transition to the RRC Inactive state accompanied by indication(s), such as parameters, to NW on remaining data frames that are unsent (volume, timing, duration to send remaining frames (e.g., P-frames). At 325, the WTRU receives configuration information (e.g., in RRCReleasewithSuspend msg) related to expectations for operating in inactive state (e.g., CG- SDT resources and duration to operate in the RRC Inactive state). At 330, the WTRU transitions to inactive state and sends the smaller frames (e.g., P-frames) in the RRC Inactive state.

[0178] Example Embodiment #3

[0179] In a third embodiment, an uplink solution may be used under the conditions of a variable based on variable latency per PDU-set when the WTRU is in the RRC Inactive state. FIG. 4 depicts an example WTRU method 400 using the third embodiment conditions.

[0180] At 405, the WTRU receives configuration information related to expectations for operating in RRC Inactive state (e.g., different CG-SDT resources and associated PDB thresholds to send data in the uplink in the Inactive state). At 410 the WTRU receives one or more PDU- set(s) to send in the uplink and an indication of PDU Set Delay Bound (PSDB). At 415, the WTRU determines whether any CG-SDT resource and associated PDB thresholds match PSDB of the PDU-set(s).

[0181] At 420, the WTRU tests if the CG-SDT resource and associated PDB threshold is suitable for all of the payload. If yes, at 425, the WTRU selects among stored/configured/approved CG- SDT configurations for a configuration that can accommodate the UL payload. At 430, the WTRU sends frames in RRC Inactive state using the selected CG-SDT configuration. Such frames may be smaller frames (e.g., P-frames).

[0182] Returning to 420, if the CG-SDT configuration(s) and associated PDB threshold(s) are not suitable, the WTRU at 435 sends an indication to the NW, for example an SR, to request for an UL grant. The WTRU at 440 receives the uplink grant from the NW. At 445, the grant is tested to determine if the UL grant is suitable for only part of the available payload. If the UL grant can accommodate all of the payload, then at 465 the WTRU sends the UL data using the CG-SDT grant.

[0183] Returning to 445, if the CG-SDT configuration(s) and associated PDB threshold(s) are suitable for only part of the payload, then at 450 the WTRU selects CG-SDT grant for the partial payload transmission. At 455 the WTRU sends an indication to NW for the remaining payload (e.g., SR to request for UL grant). At 460, the WTRU receives the resource grant (e.g., CG-SDT or DG) for the remaining payload. At 465, the WTRU sends the remaining UL payload to the NW while staying in the RRC Inactive state. Alternatively, instead of receiving an UL grant from the NW for either the payload (at 440) or the remaining payload (at 460), the WTRU may receive a release message from the NW to transition to the RRC Connected State to send the payload/remaining payload.

[0184] Example Embodiment #4

[0185] In a fourth embodiment, an uplink solution may be based on XR frame importance when the WTRU is in the RRC Inactive state. FIG. 5 depicts an example WTRU method 500 starting with the WTRU being in the RRC Inactive state.

[0186] At 505, the WTRU receives configuration information (e.g., in RRCReleasewithSuspend message) related to expectations for operating in inactive state (e.g., CG-SDT resources, XR frame importance threshold). At 510, the WTRU receives one or more PDU-set(s) to send in the uplink, along with frame importance/priority level/flag from the XR application (e.g., in PDU header or header of first PDU in PDU-set). At 515, the WTRU determines the volume and timing of data that can be sent in an RRC Inactive state based on XR application layer information (e.g., frame importance) and configuration information from step 505. [0187] At 520, the WTRU tests if the PDU-set frame importance < Threshold (or if packet priority flag = 0). If yes, then at 525, the WTRU sends data/payload frames in the RRC Inactive state using CG-SDT resources. If at 520, the PDU-set frame importance > Threshold (or if packet priority flag = 1), then the WTRU may either move to 530 and send a Resume request to transition to RRC Connected state to transmit payload or move to 535 and send an indication to the NW to request for an UL grant while remaining in the RRC Inactive state. In either event, at 540, the WTRU receives the requested grant and send the payload data in the RRC Connected state.

[0188] Example Embodiment #5

[0189] In a fifth embodiment, the WTRU receives a configuration for operating in the Inactive state. The WTRU determines the volume and timing of data that can be sent in Inactive state based on application layer information (e.g., PDU set size, remaining time, PSI) and the configuration received from the network. The WTRU determines a time duration to monitor PDCCH in Inactive state based on application layer info. The WTRU sends an indication to the NW which may include a request to modify the CG-SDT configuration or time duration to monitor PDCCH in the Inactive state. FIG. 6 depicts an example WTRU method 600 starting with the WTRU being in the RRC Inactive state.

[0190] In FIG. 6 at 605, the WTRU receives configuration information (e.g., in RRCReleasewithSuspend message) for operating in inactive state (e.g., CG-SDT config, different thresholds corresponding to payload size, remaining time, PSI.) After receiving an RRCReleasewithSuspend message with the CG-SDT configuration information, the WTRU enters the Inactive state from an RRC Connected state.

[0191] At 610, the WTRU receives one or more PDU-sets (e.g., from XR application in the WTRU) to send in an uplink transmission, (e.g., the number of I-frames/P-frames)

[0192] at 615, the WTRU determines if a change is needed to the current CG-SDT configuration (e.g., CG-SDT resources and/or CG grant periodicity) based on data in WTRU buffer and/or upcoming data, remaining time and PSI. Examples of a need for a modified CG- SDT include; (a) if the PSI > threshold and/or remaining time < a threshold (Th), (b) if the total data volume in WTRU buffer > Th, and/or (c) if upcoming data volume > Threshold.

[0193] Upcoming data may be described as data that is not yet in the WTRU buffer, but the WTRU has knowledge that it will be coming into its buffer in a near future (e.g., based on application signaling or the first PDU of a PDU set may carry information of the total number of PDUs of that PDU set). The remaining PDUs of that PDU set may not have come yet into the WTRU buffer, but the WTRU is expecting them based on the header information, for example. [0194] In one example, the WTRU may receive knowledge of the upcoming data (volume/type), for e.g., from the XR application. In another example, the WTRU may receive and/or derive knowledge of the upcoming data based on the traffic characteristics (e.g., data rates, periodicity of traffic). In another example, the header of a PDU set (e.g., first one or more PDUs of a PDU set) may carry information on the size of the entire PDU set and/or the total number of PDUs of the PDU set. In another example, one PDU set may provide the WTRU indications on the size/type/number of PDUs of an upcoming PDU set.

[0195] At 620, assuming that the WTRU determines that a change in CG-SDT is needed, then the WTRU determines a time duration/window and monitoring frequency/instances to monitor for PDCCH in Inactive state based on the data volume in its buffer and/or upcoming data and/or remaining time (e.g., based on PSDB).

[0196] At 625, the WTRU transmits an indication to NW, such as an RRC message, including information to (a) a request to modify the CG-SDT configuration (CG resources and/or CG periods), and/or (b) the determined time duration/window to monitor PDCCH in the Inactive state, and/or a Resume request to transition to CONNECTED state. Optionally, the WTRU may transmit a MAC CE/Buffer Status Report (BSR) to indicate to the NW the amount/volume of data in the WTRU buffer for example. The transmission of the request may be separate from the information of the duration/window of a modified PDCCH for the WTRU to monitor.

[0197] At 630, the WTRU receives an indication from the NW in response to the request for CG-SDT modification and PDCCH information in step 625. After receiving the NW response/indication at 630, the WTRU may take one of two actions. If the WTRU receives an updated CG-SDT configuration at 635 with larger grants or DG resources in the monitoring time duration from NW, then at 640, the WTRU in the Inactive state, uses the grant(s) to transmit all or a portion of the data received at 610. If the WTRU does not receive a new SDT grant, then the WTRU may receive a release message from NW at 645 to transition into RRC Connected state. Then, the WTRU transitions to RRC Connected state at 650 to transmit the data received at 610.

[0198] FIG. 7 depicts an example timing diagram 700 of the activity expressed in the example embodiment #5. In FIG. 7, at 710, a DL PDCCH Monitoring activity timeline is shown. At 720, an UL Transmission CG timeline is shown. At 730, an indication of a WTRU Buffer representing received PDU sets is shown with relation to 710 and 720. Initially, the WTRU receives a PDU set w/PSI=l (e.g., from XR application in UE) labeled 731. The WTRU is able to UL transmit the received PDU set labeled 731 using the UL TX CG in the timeline 720 as shown by the first uplink transmission 721 shown in the 720 timeline. At event 1, a PDU Set labeled 732 w/PSI=l is received in the WTRU buffer along with a second PDU set labeled 733 (PDU Set w/PSI=2). This can result in a trigger indication to the WTRU that the total data received (both PDU sets 732 and 733) is to be transmitted. However, the WTRU detects that the existing CG (e.g., CG-SDT grant size/periodicity) is not sufficient (e.g., CG-SDT grant size is too small, and/or CG-SDT grant periodicity is too low) to transmit the received PDU sets using SDT while in the Inactive state. Other exemplary factors in the determination that the existing CG is not sufficient are that the remaining time (e.g., remaining time before PSDB expires) < a threshold and/or that the PSI of data in WTRU buffer > a threshold (e.g., PSI=2 > a threshold).

[0199] After a determination at event 1 is made that the existing CG is not sufficient to transmit the received PDU data sets 732 and 733, then event 2 may occur. At event 2, the WTRU determines new PDCCH monitoring parameters (e.g., PDCCH monitoring occasions/slots/time, PDCCH monitoring duration, etc.) which may be based, for example, on the amount of data in the WTRU buffer. In the example of FIG. 7, the WTRU data buffer has PDU data sets 732 and 733. For example, in determining new PDCCH monitoring parameters, the higher the volume of data in the WTRU buffer, the longer the PDCCH monitoring duration may need to be. In another example, the higher the PSI of the data in the WTRU buffer, the more frequent the PDCCH monitoring occasions may need to be. The new PDCCH monitoring parameters are those that allow the WTRU to monitor the DL channel to the WTRU such that any new dynamic grants or any new/updated (re)configured CG and/or CG-SDT that is transmitted to the WTRU may be received in time by the WTRU and used to transmit the UL data.

[0200] At event 3, the WTRU provides an indication 722 to the network of a request for a change in CG (e.g., updated and/or new CG-SDT configuration, e.g., with larger CG-SDT grants or higher CG-SDT grant periodicity), new monitoring parameters for the PDCCH (e.g., more frequency monitoring occasions, longer monitoring duration), and/or buffer information (e.g., volume of data and/or upcoming data in WTRU buffer). The indication 722 (request for a change) may be a MAC CE/BSR or other message sent by the WTRU to the network. The request for a change in CG and/or change in PDCCH monitoring parameters may be granted by the network. At event 4, the WTRU monitors the PDCCH using the new PDCCH parameters depicted at 711. If the network approves the request of the indication at 722, the WTRU may receive a dynamic grant (DG) and/or a CG reconfiguration from the network. In one example shown in FIG. 7, the WTRU may receive from the network a dynamic grant which may be used for at least some of the received PDU set data 732 and 733. An example UL transmission using a one-time dynamic grant is shown at 723. An example result of a new CG Reconfiguration received from the NW is shown as the transmission at 724 of the PDU data sets in the WTRU buffer at 734. One or both of these grant accommodations may allow the WTRU to UL transmit the two received PDU sets (732 and 733). The grant accommodations from the network may include a reconfigured/modified/changed CG (e.g., CG-SDT configuration) and/or any additional grant (such as a dynamic grant) that may be provided to the WTRU in response to the WTRU indication 722 (e.g., via MAC CE/BSR) provided to the network. Thereafter, the WTRU may be able to accommodate the transmission of received PDU data sets using SDT while in the Inactive state. For example, if a new/updated/more frequent CG-SDT grant is provided to the WTRU, then the PDU sets received at the WTRU buffer at 736 may be transmitted using the new CG-SDT grant at 725.

Conclusion

[0201] Although features and elements are provided 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. The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations may be made without departing from its spirit and scope, as will be apparent to those skilled in the art. No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly provided as such. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods or systems.

[0202] The foregoing embodiments are discussed, for simplicity, with regard to the terminology and structure of infrared capable devices, i.e., infrared emitters and receivers. However, the embodiments discussed are not limited to these systems but may be applied to other systems that use other forms of electromagnetic waves or non-electromagnetic waves such as acoustic waves. [0203] 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, the term "video" or the term "imagery" may mean any of a snapshot, single image and/or multiple images displayed over a time basis. As another example, when referred to herein, the terms "user equipment" and its abbreviation "UE", the term "remote" and/or the terms "head mounted display" or its abbreviation "HMD" may mean or include (i) a wireless transmit and/or receive unit (WTRU); (ii) any of a number of embodiments of a WTRU; (iii) a wireless-capable and/or wired-capable (e.g., tetherable) device configured with, inter alia, some or all structures and functionality of a WTRU; (iii) a wireless-capable and/or wired-capable device configured with less than all structures and functionality of a WTRU; or (iv) the like. Details of an example WTRU, which may be representative of any WTRU recited herein, are provided herein with respect to FIGs. 1 A-1D. As another example, various disclosed embodiments herein supra and infra are described as utilizing a head mounted display. Those skilled in the art will recognize that a device other than the head mounted display may be utilized and some or all of the disclosure and various disclosed embodiments can be modified accordingly without undue experimentation. Examples of such other device may include a drone or other device configured to stream information for providing the adapted reality experience.

[0204] In addition, the methods provided herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0205] Variations of the method, apparatus and system provided above are possible without departing from the scope of the invention. In view of the wide variety of embodiments that can be applied, it should be understood that the illustrated embodiments are examples only, and should not be taken as limiting the scope of the following claims. For instance, the embodiments provided herein include handheld devices, which may include or be utilized with any appropriate voltage source, such as a battery and the like, providing any appropriate voltage.

[0206] Moreover, in the embodiments provided above, processing platforms, computing systems, controllers, and other devices that include processors are noted. These devices may include 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 may be performed by the various CPUs and memories. Such acts and operations or instructions may be referred to as being "executed," "computer executed" or "CPU executed."

[0207] One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU's operation, as well as other processing of signals. The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits. It should be understood that the embodiments are not limited to the above-mentioned platforms or CPUs and that other platforms and CPUs may support the provided methods. [0208] The data bits may also be maintained on a computer readable medium 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 may include cooperating or interconnected computer readable medium, which exist exclusively on the processing system or are distributed among multiple interconnected processing systems that may be local or remote to the processing system. It should be understood that the embodiments are not limited to the above-mentioned memories and that other platforms and memories may support the provided methods.

[0209] In an illustrative embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and/or any other computing device.

[0210] There is little distinction left between hardware and software implementations of aspects of systems. The use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software may become significant) a design choice representing cost versus efficiency tradeoffs. There may be various vehicles by which processes and/or systems and/or other technologies described herein may be effected (e.g., hardware, software, and/or firmware), and the preferred vehicle may 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 may opt for a mainly hardware and/or firmware vehicle. If flexibility is paramount, the implementer may opt for a mainly software implementation. Alternatively, the implementer may opt for some combination of hardware, software, and/or firmware.

[0211] The foregoing 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 include 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 may be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In an embodiment, several portions of the subject matter described herein may 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, may 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 may be distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium 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 communications link, a wireless communication link, etc.).

[0212] Those skilled in the art will recognize that it is common within the art to describe devices and/or processes in the fashion set forth herein, and thereafter use engineering practices to integrate such described devices and/or processes into data processing systems. That is, at least a portion of the devices and/or processes described herein may be integrated into a data processing system via a reasonable amount of experimentation. Those having skill in the art will recognize that a typical data processing system may generally include one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices, such as a touch pad or screen, and/or control systems including feedback loops and control motors (e.g., feedback for sensing position and/or velocity, control motors for moving and/or adjusting components and/or quantities). A typical data processing system may be implemented utilizing any suitable commercially available components, such as those typically found in data computing/communication and/or network computing/communication systems.

[0213] The herein described subject matter sometimes illustrates different components included within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures may 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 may be achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated may 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 may 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.

[0214] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

[0215] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, where only one item is intended, the term "single" or similar language may be used. As an aid to understanding, the following appended claims and/or the descriptions herein may include usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim including such introduced claim recitation to embodiments including only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should be interpreted to mean "at least one" or "one or more"). The same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A orB" will be understood to include the possibilities of "A" or "B" or "A and B." Further, the terms "any of' followed by a listing of a plurality of items and/or a plurality of categories of items, as used herein, are intended to include "any of," "any combination of," "any multiple of," and/or "any combination of multiples of the items and/or the categories of items, individually or in conjunction with other items and/or other categories of items. Moreover, as used herein, the term "set" 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. And the term "multiple", as used herein, is intended to be synonymous with "a plurality".

[0216] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0217] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein may be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one 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 which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth. [0218] Moreover, the claims should not be read as limited to the provided order or elements unless stated to that effect. In addition, use of the terms "means for" in any claim is intended to invoke 35 U.S.C. §112, 6 or means-plus-function claim format, and any claim without the terms "means for" is not so intended.

Claims

CLAIMS What is claimed is:

1. A WTRU comprising circuitry configured to: receive configuration information indicating parameters associated with (i) first configured grant resources for small data transmission (CG-SDT), and (ii) threshold values associated with transmission time according to a delay budget for a protocol data unit (PDU) set (PSDB) and importance information for a PDU set (PSI); receive one or more PDU sets having PDU set information comprising PSI and PSDB information for each PDU set; determine that the first CG-SDT cannot accommodate transmission of uplink data of the one or more PDU sets received by the WTRU, the determination based on one or more of the PDU set information, and an amount of data of the PDU sets in an uplink buffer of the WTRU; determine a physical downlink control channel (PDCCH) monitoring time duration to be used by the WTRU; and transmit an indication to a network to request a second CG-SDT.

2. The WTRU of claim 1, further configured to transmit an indication of the determined PDCCH monitoring time duration.

3. The WTRU of claim 1, further configured to: receive from the network the second CG-SDT; and transmit, in accordance with the second CG-SDT while in a radio resource control Inactive state, the one or more PDU sets received by the WTRU.

4. The WTRU of claim 1, further configured to: receive from the network an indication to enter a radio resource control (RRC) Connected state; and transmit the one or more PDU sets in the RRC Connected state.

5. The WTRU of claim 1, wherein the WTRU receives the configuration information while in either a radio resource control (RRC) Connected state or an RRC Inactive state.

6. The WTRU of claim 1, wherein the WTRU receives the one or more PDU sets, from an application layer, while in a radio resource control Inactive state.

7. The WTRU of claim 1, wherein the WTRU transmits the request for the second CG-SDT during an uplink transmission time of the first configured grant resource.

8. The WTRU of claim 1, wherein the WTRU determines both the PDCCH monitoring time duration and frequency of PDCCH monitoring occasions.

9. A method performed by a wireless transmit/receive unit (WTRU), the method comprising: receiving configuration information indicating parameters associated with (i) first configured grant resources for small data transmission (CG-SDT), and (ii) threshold values associated with transmission time according to a delay budget for a protocol data unit (PDU) set (PSDB) and importance information for a PDU set (PSI); receiving one or more PDU sets having PDU set information comprising PSI and PSDB information for each PDU set; determining that the first CG-SDT cannot accommodate transmission of uplink data of the one or more PDU sets received by the WTRU, the determination based on one or more of the PDU set information, and an amount of data of the PDU sets in an uplink buffer of the WTRU; determining a physical downlink control channel (PDCCH) monitoring time duration to be used by the WTRU; and transmitting an indication to a network to request a second CG-SDT.

10. The method of claim 9 further comprising: transmitting an indication of the determined PDCCH monitoring time duration.

11. The method of claim 10, wherein the determined PDCCH monitoring time duration comprises a monitoring time to receive the second CG-SDT.

12. The WTRU of claim 1, further comprising: receiving from the network the second CG-SDT; and transmitting, in accordance with the second CG-SDT while in a radio resource control Inactive state, the one or more PDU sets received by the WTRU.

13. The method of claim 9, further comprising: receiving an indication to enter a radio resource control (RRC) Connected state; and transmitting the one or more PDU sets in RRC Connected state.

14. The method of claim 9, wherein receiving the configuration information occurs while in either a radio resource control (RRC) Connected state or a RRC Inactive state.

15. The method of claim 9, wherein receiving the one or more PDU sets from an application layer occurs while in a radio resource control Inactive state.

16. The method of claim 9, wherein transmitting the indication to the network to request the second CG-SDT occurs during an uplink transmission time of the first configured grant resource.

17. The method of claim 9, wherein determining the PDCCH monitoring time duration further comprises determining a frequency of PDCCH monitoring occasions.

18. A non-transient computer-readable media having instructions thereon, which when executed by a wireless transmit/receive unit (WTRU), perform the method of any of claims 9- 17.