Methods for verifying channel status

Abstract

Line-of-Sight (LOS) indicator verification is performed by a Wireless Transmitter / Receiver Unit (WTRU) to a Target Transmit / Receiver Point (TRP) that transmits a Positioning Reference Signal (PRS). The WTRU receives a request to verify the LOS indicator and an SRS resource ID, and receives the PRS from the Target Transmit / Receiver Point (TRP). The WTRU measures the characteristics of the PRS, determines the associated LOS indicator, and compares the determined LOS indicator to a configured threshold. When the determined LOS indicator is below the configured threshold, the WTRU transmits a Sounding Reference Signal (SRSp) associated with the SRS resource ID within a configured time window from the reception of the PRS. Additional embodiments are disclosed.

Description

Technical Field

[0001] This disclosure relates to a method for verifying channel status.

Background Art

[0002] Cross - reference to Related Applications This application claims the benefit of U.S. Patent Provisional Application No. 63 / 457,002, filed on April 4, 2023, the content of which is incorporated herein by reference.

[0003] Wireless-based positioning may employ data-driven methods, such as machine learning algorithms, where a training dataset containing positioned measurements is used to train a model that translates measurements into location. To achieve good positioning performance under both line-of-sight (LOS) and non-line-of-sight (NLOS) conditions, the data should be separated into LOS and NLOS data before training the machine learning algorithm. Current wireless networks may use LOS indicators in positioning methods. For example, LOS indicators may be used in the downlink to client devices such as wireless transceiver units (WTRUs) to assist downlink-based positioning methods, either per transmit / receive point (TRP) or per positioning reference signal (PRS) resource. In the uplink, WTRUs may also display LOS indicators to the network (e.g., point management functions (LMFs), gNBs, etc.) per TRP or per positioning reference signal (PRS) resource. Artificial intelligence machine learning (AIML) models may be trained to generate LOS indicators as labels or estimates based on input (e.g., measurements). LOS indicators can be generated by WTRUs or networks, but currently the quality of LOS indicators is not validated by the WTRU or network. Therefore, when a network or WTRU trains an AIML model by setting the LOS indicator generated by the WTRU or network as the desired target, and the LOS indicator is not validated, the output of the AIML model (e.g., inference) (e.g., the inferred LOS indicator) may be unreliable. Thus, the reliability of LOS indicators needs to be improved, and AIML models using LOS indicators should be further refined. [Overview of the project]

[0004] Aspects of the embodiments may relate to AIML positioning and measurement procedures for wireless networks. A WTRU receives configuration information for line-of-sight (LOS) indicator verification, including thresholds, associated time windows, and one or more sounding reference signals (SRSp) for positioning. In one example of an uplink (UL) transmission procedure, the WTRU determines a line-of-sight (LOS) indicator for a target transmit / receive point (TRP), such as a gNB or point management function (LMF), based on measurements made on the received positioning reference signal (PRS). In one embodiment, the WTRU decides to transmit a configured sounding reference signal (SRSp) for positioning to the network if at least one condition for initiating the LOS verification procedure is met (e.g., the determined LOS indicator is below a configured threshold). Thus, the LOS indicator can be verified for use in AIML modeling. Additional embodiments are disclosed.

[0005] A more detailed understanding can be obtained from the following explanation, which is provided as an example along with the attached drawings, and similar reference numbers in the drawings refer to the same elements. [Brief explanation of the drawing]

[0006] [Figure 1A] This is a system diagram showing an exemplary communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] This is a system diagram showing an exemplary wireless transmit / receive unit (WTRU) that may be used in the communication system shown in Figure 1A, according to one embodiment. [Figure 1C] This is a system diagram showing an exemplary radio access network (RAN) and an exemplary core network (CN) that may be used in the communication system shown in Figure 1A according to one embodiment. [Figure 1D] This is a system diagram showing further exemplary RAN and further exemplary CN that may be used in the communication system shown in Figure 1A according to one embodiment. [Figure 2] This is a diagram illustrating an exemplary three-layer neural network. [Figure 3] This is a functional diagram showing examples of line-of-sight (LOS) indicators associated with transmit / receive points (TRPs) and LOS indicators associated with positioning reference signals (PRS). [Figure 4] This figure shows exemplary scenarios for the PRS transmission direction and SRS transmission direction. [Figure 5] This is a positional diagram showing the transmission angle from the TRP's perspective and the transmission angle from the WTRU's perspective. [Figure 6] This is a functional diagram showing the different transmit (Tx) and receive (Rx) angles that can occur in PRS transmission between TRP and WTRU. [Figure 7] This is a directional diagram showing spatially adjacent SRS transmissions from WTRU. [Figure 8] This is a functional diagram illustrating three examples of receiving positioning reference signals (PRS) and transmitting sounding reference signals (SRSp) for positioning. [Figure 9] This is a functional diagram showing an example of SRS transmission after PRS reception. [Figure 10] This is a spatial diagram showing the relationship between SRS and Channel Status Information (CSI) reference signal (RS) in one example. [Figure 11] This is a functional diagram showing examples of multiple SRSs spatially related to PRS transmission. [Figure 12] This timing diagram illustrates an exemplary time limit for sending an SRS after receiving a PRS. [Figure 13] This is a flowchart illustrating one method for verifying an LOS indicator according to a certain embodiment. [Figure 14] This is a flowchart of another method for verifying an LOS indicator according to a certain embodiment. [Modes for carrying out the invention]

[0007] Figure 1A shows an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, and broadcast to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communication system 100 may utilize one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique-word OFDM (UW-OFDM), resource-block filtered OFDM, and filtered-bank multi-carrier (FBMC).

[0008] As shown in Figure 1A, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the internet 110, and other networks 112, but it will be understood that the disclosed embodiments intend any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, and 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, WTRU102a, 102b, 102c, and 102d, any of which may be called base stations (STAs), may be configured to transmit and / or receive wireless signals and may include user equipment (UEs), mobile stations, fixed or mobile subscriber units, contract-based units, pagers, mobile phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), automobiles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronic devices, and devices operating on commercial and / or industrial wireless networks. Any of WTRU102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0009] The communication system 100 may also include base stations 114a and / or base stations 114b. Each of the base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks such as CN 106, the Internet 110, and / or other networks 112. As an example, base stations 114a and 114b may be a base transceiver base station (BTS), a next-generation NodeB such as a NodeB, eNode B (eNB), a Home Node B, a Home eNode B, a gNode B (gNB), a new radio (NR) NodeB, a site controller, an access point (AP), a wireless router, and the like. Although base stations 114a and 114b are each illustrated as single elements, it will be understood that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[0010] Base station 114a may be part of RAN 104, 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), and relay nodes. Base stations 114a and / or base stations 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, sometimes referred to as cells (not shown). These frequencies may be in the licensed spectrum, the unlicensed spectrum, or a combination of the licensed and unlicensed spectrum. A cell may provide coverage for a wireless service in a particular geographic area that may be relatively constant or change over time. A cell may be further divided into cell sectors. For example, a cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, base station 114a may utilize multiple input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming can be used to transmit and / or receive signals in a desired spatial direction.

[0011] Base stations 114a, 114b may communicate with one or more WTRUs 102a, 102b, 102c, 102d via an air interface 116, the air interface 116 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).

[0012] More specifically, as described above, the communication system 100 may be a multiple access system and may utilize one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA. For example, base stations 114a and WTRUs 102a, 102b, and 102c in RAN 104 may implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA) that can establish an air interface 116 using broadband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High-Speed ​​Uplink (UL) Packet Access (HSUPA).

[0013] In one embodiment, base stations 114a and WTRUs 102a, 102b, 102c may implement radio technologies such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can establish an air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0014] In one embodiment, base stations 114a and WTRUs 102a, 102b, and 102c may implement radio technologies such as NR radio access, which can establish an air interface 116 using NR.

[0015] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for example, using the principle of dual connectivity (DC). Accordingly, the air interfaces 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., eNBs and gNBs).

[0016] In other embodiments, base station 114a and WTRUs 102a, 102b, 102c may implement wireless technologies such as IEEE802.11 (i.e., Wireless Fidelity (WiFi)), IEEE802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0017] The base station 114b in FIG. 1A may be a wireless router, a Home Node B, a Home eNode B, or an access point, and may utilize any suitable RAT for facilitating wireless connections in a local area, such as an office, a residence, a vehicle, a campus, industrial facilities, an aerial corridor (e.g., for use by drones), a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a wireless technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In certain embodiments, the base station 114b and the WTRUs 102c, 102d may implement a wireless technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a pico cell or a femto cell. 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.

[0018] RAN104 may communicate with CN106, 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 WTRU102a, 102b, 102c, and 102d. The data may have various Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, fault tolerance requirements, reliability requirements, data throughput requirements, and mobility requirements. CN106 may provide call control, billing services, mobile location-based services, prepaid calls, internet connectivity, video distribution, and / or implement high-level security features such as user authentication. Although not shown in Figure 1A, it will be understood that RAN104 and / or CN106 may communicate directly or indirectly with other RANs that utilize the same RAT as RAN104 or different RATs. For example, in addition to connecting to RAN104 which may utilize NR radio technology, CN106 may also communicate with another RAN (not shown) which utilizes GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0019] CN106 may also serve as a gateway for WTRU102a, 102b, 102c, and 102d to access PSTN108, the Internet 110, and / or other networks 112. PSTN108 may include a circuit-switched telephone network providing basic telephone services (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using common communication protocols such as the Transmit Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) of the TCP / IP Internet Protocol suite. Network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, network 112 may include another CN connected to one or more RANs, which may utilize the same RAT as RAN104 or a different RAT.

[0020] Some or all of the WTRUs 102a, 102b, 102c, and 102d in the communication system 100 may include multimode capability (for example, WTRUs 102a, 102b, 102c, and 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). For example, WTRU 102c, shown in Figure 1A, may be configured to communicate with base station 114a that can utilize cellular-based radio technology and with base station 114b that can utilize IEEE 802 radio technology.

[0021] Figure 1B is a system diagram showing an exemplary WTRU 102. As shown in Figure 1B, the WTRU 102 may include, among other things, 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 supply 134, a Global Positioning System (GPS) chipset 136, and / or other peripherals 138. It will be understood that the WTRU 102 may include any partial combination of the elements described above, while remaining consistent with the embodiment.

[0022] The processor 118 could be a general-purpose processor, a dedicated processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functions that enable the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to a transceiver 120 which can be coupled to a transmit / receive element 122. Although Figure 1B illustrates the processor 118 and transceiver 120 as separate components, it will be understood that the processor 118 and transceiver 120 can be integrated together in an electronic package or chip.

[0023] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF signals and optical signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0024] Although the transmit / receive element 122 is illustrated as a single element in Figure 1B, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may utilize MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via the air interface 116.

[0025] The transceiver 120 may be configured to modulate the signal to be transmitted by the transmit / receive element 122 and to demodulate the signal to be received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multimode capability. Therefore, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate through multiple RATs, such as NR and IEEE 802.11.

[0026] The processor 118 of the WTRU102 may be coupled to a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (for example, a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit) and may receive user input data from there. 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 any type of suitable memory, such as non-removable memory 130 and / or removable memory 132, and may store data therein. 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. Removable memory 132 may include a subscriber identification 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 memory not physically located in the WTRU 102, such as a server or home computer (not shown), and may store data therein.

[0027] The processor 118 may receive power from the power supply 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 can be any suitable device for supplying power to the WTRU 102. For example, the power supply 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.), a solar cell, a fuel cell, etc.

[0028] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) about the current location of the WTRU 102. In addition to, or instead of, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be understood that the WTRU 102 may acquire location information by any suitable location determination method while remaining consistent with one embodiment.

[0029] The processor 118 may also be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functions, and / or wired or wireless connectivity. For example, peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a Universal Serial Bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulation (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. Peripherals 138 may include one or more sensors. The sensors may be one or more of the following: a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, a compass sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a barometer, a gesture sensor, a biometric sensor, a humidity sensor, and the like.

[0030] WTRU102 may include a full-duplex radio that is associated with specific subframes for both the transmission and reception of some or all of the signals (e.g., UL (e.g., for transmission) and DL (e.g., for reception)), but which may be simultaneous and / or concurrent. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference, either through hardware (e.g., chokes) or through signal processing via a processor (e.g., via a separate processor (not shown) or processor 118). In one embodiment, WTRU102 may include a half-duplex radio that is the transmission and reception of some or all of the signals (e.g., associated with specific subframes for either UL (e.g., for transmission) or DL ​​(e.g., for reception)).

[0031] Figure 1C is a system diagram showing RAN104 and CN106 according to one embodiment. As described above, RAN104 may utilize E-UTRA radio technology to communicate with WTRU102a, 102b, and 102c via air interface 116. RAN104 may also communicate with CN106.

[0032] RAN104 may include eNode-B160a, 160b, and 160c, but it will be understood that RAN104 may include any number of eNode-B while remaining consistent with a particular embodiment. Each of eNode-B160a, 160b, and 160c may include one or more transceivers for communicating with WTRU102a, 102b, and 102c via the air interface 116. In one embodiment, eNode-B160a, 160b, and 160c may implement MIMO technology. Thus, eNode-B160a may use multiple antennas, for example, to transmit a wireless signal to and / or receive a wireless signal from WTRU102a.

[0033] Each of the eNode-B160a, 160b, and 160c may be associated with a specific cell (not shown) and may be configured to handle wireless resource management decisions, handover decisions, user scheduling in UL and / or DL, etc. As shown in Figure 1C, the eNode-B160a, 160b, and 160c can communicate with each other via the X2 interface.

[0034] The CN106 shown in Figure 1C may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (PGW) 166. Although the elements described above are illustrated as part of CN106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0035] MME162 may be connected to each of the eNode-B162a, 162b, and 162c in RAN104 via the S1 interface and may also function as a control node. For example, MME162 may be responsible for authenticating users of WTRU102a, 102b, and 102c, activating / deactivating bearers, and selecting a specific serving gateway during the initial connection of WTRU102a, 102b, and 102c. MME162 may provide control plane functionality for switching between RAN104 and other RANs (not shown) utilizing other radio technologies such as GSM and / or WCDMA.

[0036] The SGW164 can be connected to each of the eNode B160a, 160b, and 160c in RAN104 via the S1 interface. The SGW164 can generally route and forward user data packets to and from WTRU102a, 102b, and 102c. The SGW164 can perform other functions such as fixing the user plane during handovers between eNode B, triggering paging when DL data is available for WTRU102a, 102b, and 102c, and managing and remembering the context of WTRU102a, 102b, and 102c.

[0037] SGW164 may be connected to PGW166, which may provide WTRU102a, 102b, and 102c with access to a packet-switched network such as the Internet 110 to facilitate communication between WTRU102a, 102b, and 102c and an IP-enabled device.

[0038] CN106 can facilitate communication with other networks. For example, CN106 may provide WTRU102a, 102b, and 102c with access to a circuit-switched network such as PSTN108 to facilitate communication between WTRU102a, 102b, and 102c and conventional fixed telephone line communication devices. For example, CN106 may include, or communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) acting as an interface between CN106 and PSTN108. In addition, CN106 may provide WTRU102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0039] Although WTRUs are described as wireless terminals in Figures 1A to 1D, in some representative embodiments, such terminals are intended to use wired communication interfaces (e.g., temporary or permanent) with a communication network.

[0040] In a typical embodiment, the other network 112 may be a WLAN.

[0041] In Infrastructure Basic Service Set (BSS) mode, a WLAN may have access points (APs) for the BSS and one or more stations (STAs) associated with the APs. APs may have access to or interfaces with a distribution system (DS) or another type of wired / wireless network that carries traffic to and from the BSS. Traffic originating outside the BSS and destined for an STA may arrive through an AP and be delivered to the STA. Traffic originating from an STA and destined for a destination outside the BSS may be sent to an AP to be delivered to its respective destination. Traffic between STAs within a BSS may be transmitted through an AP; for example, a source STA may send traffic to an AP, and the AP may deliver the traffic to a destination STA. Traffic between STAs within a BSS is considered and / or may be referred to as peer-to-peer traffic. Peer-to-peer traffic may be transmitted between a source STA and a destination STA (for example, directly between them) using a Direct Link Setup (DLS). In some representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using Independent BSS (IBSS) mode may not have APs, and STAs within or using IBSS (e.g., all STAs) can communicate directly with one another. The IBSS communication mode is sometimes referred to herein as the “ad hoc” communication mode.

[0042] When using the 802.11ac infrastructure operating mode or a similar operating mode, an AP may transmit beacons on a fixed channel, such as a primary channel. The primary channel may have a fixed width (e.g., a 20 MHz bandwidth) or a dynamically set width. The primary channel may also be the operating channel of the BSS and may be used by an STA to establish a connection with the AP. In some typical embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. In CSMA / CA, an STA, including the AP (e.g., any STA), may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, that particular STA may make concessions. A single STA (e.g., only one station) may transmit at any given time within a given BSS.

[0043] A high-throughput (HT) STA may use a 40MHz wide channel for communication via a combination of a primary 20MHz channel and adjacent or non-adjacent 20MHz channels to form a 40MHz wide channel, for example.

[0044] Ultra-high throughput (VHT) STAs may support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. 40 MHz and / or 80 MHz channels may be formed by combining consecutive 20 MHz channels. 160 MHz channels may be formed by combining eight consecutive 20 MHz channels, or by combining two non-consecutive 80 MHz channels, which may be called an 80+80 configuration. In an 80+80 configuration, the data after channel coding may pass through a segment parser that can split the data into two streams. Inverse fast Fourier transform (IFFT) and time-domain processing may be performed separately on each stream. The streams may be mapped to two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of a receiving STA, the operation described above for the 80+80 configuration may be reversed, and the combined data may be transmitted to a medium access control (MAC).

[0045] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz using the non-TVWS spectrum. According to one typical embodiment, 802.11ah may support metric-type control / MTC, such as machine-type communications (MTC) devices in a macro coverage area. An MTC device may have limited capabilities, including support for some and / or limited bandwidths (e.g., only that support). An MTC device may include a battery with a battery life exceeding a certain threshold (e.g., to maintain a very long battery life).

[0046] WLAN systems that can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that can be designated as the primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by one of the STAs among all STAs operating in the BSS that supports the minimum bandwidth operating mode. In the 802.11ah example, the primary channel may be 1 MHz wide for an STA (e.g., an MTC type device) that supports (e.g., only) 1 MHz mode, even if other STAs in the AP and BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier detection and / or network allocation vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, because an STA (which only supports 1MHz operating mode) is transmitting to the AP, then all available frequency bands may be considered busy, even if the majority of the available frequency bands remain idle.

[0047] In the United States, the available frequency band that can be used by 802.11ah is from 902 MHz to 928 MHz. In South Korea, the available frequency band is from 917.5 MHz to 923.5 MHz. In Japan, the available frequency band is from 916.5 MHz to 927.5 MHz. The total available bandwidth for 802.11ah is from 6 MHz to 26 MHz, depending on the country code.

[0048] Figure 1D is a system diagram showing RAN104 and CN106 according to one embodiment. As described above, RAN104 may utilize NR radio technology to communicate with WTRU102a, 102b, and 102c via the air interface 116. RAN104 may also communicate with CN106.

[0049] RAN104 may include gNB180a, 180b, and 180c, but it will be understood that RAN104 may include any number of gNBs while remaining consistent with a particular embodiment. Each of gNB180a, 180b, and 180c may include one or more transceivers for communicating with WTRU102a, 102b, and 102c via the air interface 116. In one embodiment, gNB180a, 180b, and 180c may implement MIMO technology. For example, gNB180a and 180b may utilize beamforming to transmit signals to and / or receive signals from gNB180a, 180b, and 180c. Thus, gNB180a may, for example, use multiple antennas to transmit and / or receive wireless signals from WTRU102a. In a particular embodiment, gNB180a, 180b, and 180c may implement carrier aggregation technology. For example, gNB180a may transmit multiple component carriers to WTRU102a (not shown). A subset of these component carriers may be on the unlicensed spectrum, while the remaining component carriers may be on the licensed spectrum. In one embodiment, gNB180a, 180b, and 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU102a may receive coordinated transmissions from gNB180a and gNB180b (and / or gNB180c).

[0050] WTRU102a, 102b, and 102c may communicate with gNB180a, 180b, and 180c using transmissions associated with scalable numerology. For example, OFDM symbol intervals and / or OFDM subcarrier intervals may differ for different transmissions, different cells, and / or different parts of the wireless transmission spectrum. WTRU102a, 102b, and 102c may communicate with gNB180a, 180b, and 180c using subframes or transmit time intervals (TTIs) of varying or scalable lengths (e.g., including a variable number of OFDM symbols and / or a variable-length absolute time that continues).

[0051] gNB180a, 180b, and 180c can be configured to communicate with WTRU102a, 102b, and 102c in standalone and / or non-standalone configurations. In a standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c without accessing other RANs (e.g., eNode-B160a, 160b, and 160c). In a standalone configuration, WTRU102a, 102b, and 102c can utilize one or more gNB180a, 180b, and 180c as mobility anchor points. In a standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c using signals in unlicensed band. In a non-standalone configuration, WTRU102a, 102b, and 102c can communicate with / connect to gNB180a, 180b, and 180c while also communicating with / connecting to other RANs such as eNode-B160a, 160b, and 160c. For example, WTRU102a, 102b, and 102c can implement DC principles to communicate substantially simultaneously with one or more gNB180a, 180b, and 180c and one or more eNode-B160a, 160b, and 160c. In a non-standalone configuration, eNode-B160a, 160b, and 160c may act as mobility anchors for WTRU102a, 102b, and 102c, and gNB180a, 180b, and 180c may provide additional coverage and / or throughput to service WTRU102a, 102b, and 102c.

[0052] Each of the gNB180a, 180b, and 180c may be associated with a specific cell (not shown) and may be configured to handle wireless resource management decisions, handover decisions, user scheduling in UL and / or DL, support for network slicing, interconnection between DC, NR and E-UTRA, routing of user plane data to user plane functions (UPF) 184a and 184b, and routing of control plane information to access and mobility management functions (AMF) 182a and 182b. As shown in Figure 1D, the gNB180a, 180b, and 180c can communicate with each other over the Xn interface.

[0053] The CN106 shown in Figure 1D may include at least one AMF182a, 182b, at least one UPF184a, 184b, at least one Session Management Function (SMF)183a, 183b, and optionally a Data Network (DN)185a, 185b. Although the elements described above are illustrated as part of CN106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0054] AMF182a and 182b may be connected to one or more gNB180a, 180b, and 180c in RAN104 via the N2 interface and may act as control nodes. For example, AMF182a and 182b may be responsible for authenticating users of WTRU102a, 102b, and 102c, supporting network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selecting specific SMF183a and 183b, managing registration areas, terminating non-accessible layer (NAS) signaling, and mobility management. Network slicing may be used by AMF182a and 182b to customize CN support for WTRU102a, 102b, and 102c based on the type of services utilized by WTRU102a, 102b, and 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-high reliability low latency (URLLC) access, services relying on extended large-scale mobile broadband (eMBB) access, and services for MTC access. The AMF182a and 182b may provide control plane functionality for switching between RAN104 and other RANs (not shown) that utilize other radio technologies such as LTE, LE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0055] SMF183a and 183b can be connected to AMF182a and 182b in CN106 via the N11 interface. SMF183a and 183b can also be connected to UPF184a and 184b in CN106 via the N4 interface. SMF183a and 183b can select and control UPF184a and 184b and configure traffic routing through UPF184a and 184b. SMF183a and 183b can perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy management and QoS, and providing DL data notifications. PDU session types can be IP-based, non-IP-based, Ethernet-based, etc.

[0056] UPF184a, 184b may be connected via the N3 interface to one or more gNB180a, 180b, 180c in RAN104, and RAN104 may provide WTRU102a, 102b, 102c with access to a packet-switched network such as the Internet 110 to facilitate communication between WTRU102a, 102b, 102c and IP-enabled devices. UPF184a, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering DL packets, and providing mobility anchoring.

[0057] CN106 can facilitate communication with other networks. For example, CN106 may include, or communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN106 and PSTN108. In addition, CN106 can provide WTRU102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRU102a, 102b, 102c may be connected to local DN185a, 185b through UPF184a, 184b via an N3 interface to UPF184a, 184b and an N6 interface between UPF184a, 184b and DN185a, 185b.

[0058] In view of Figures 1A–1D and their corresponding descriptions, one or more, or all, of the functions described herein with respect to one or more of the WTRU102a–d, base stations 114a–b, eNode-B160a–c, MME162, SGW164, PGW166, gNB180a–c, AMF182a–b, UPF184a–b, SMF183a–b, DN185a–b, and / or any other devices described herein may be implemented by one or more emulation devices (not shown). An emulation device may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, an emulation device may be used to test other devices and / or to simulate network and / or WTRU functions.

[0059] Emulation devices may be designed to perform one or more tests on other devices in a laboratory environment and / or a carrier network environment. For example, one or more emulation devices may perform one or more or all of the functions of a wired and / or wireless communication network, fully or partially implemented and / or deployed as part of a wired and / or wireless communication network, in order to test other devices in a communication network. One or more emulation devices may perform one or more or all of the functions of a wired and / or wireless communication network, while being temporarily implemented / deployed as part of a wired and / or wireless communication network. Emulation devices may be directly coupled to another device for the purpose of testing and / or performing tests using over-the-air wireless communication.

[0060] One or more emulation devices may perform one or more functions, including all functions, without being implemented / deployed as part of a wired and / or wireless communication network. For example, emulation devices may be used in a test laboratory and / or in test scenarios in undeployed (e.g., experimental) wired and / or wireless communication networks to perform testing of one or more components. One or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (e.g., which may include one or more antennas) may be used by emulation devices to transmit and / or receive data.

[0061] The following is a description of examples of mobile positioning methods. Rel.16 uses downlink positioning methods, uplink positioning methods, and downlink and uplink positioning methods.

[0062] "DL positioning method" can refer to any positioning method that uses a downlink reference signal, such as a positioning reference signal (PRS). The WTRU receives multiple reference signals from the transmit point (TP) and measures the downlink received signal time difference (DL RSTD) and / or reference signal received power (RSRP). Examples of DL positioning methods are downlink launch angle (DL-AoD) or downlink arrival time difference (DL-TDOA) positioning.

[0063] "UL positioning method" may refer to any positioning method that uses an uplink reference signal, such as a sounding reference signal (SRS) for positioning, referred to herein as SRSp. The WTRU transmits the SRS to several receiving points (RPs), and the RPs measure the uplink relative time of arrival (UL RTOA) and / or RSRP. Examples of UL positioning methods are uplink time of arrival difference (UL-TDOA) or angle of arrival (UL-AoA) positioning.

[0064] The term "DL and UL positioning method" can refer to any positioning method that uses both uplink and downlink reference signals for positioning. In one example, a WTRU transmits an SRS to multiple transmit / receive points (TRPs), and a gNB measures the Rx-Tx time difference calculated based on the arrival time of the DL RS (e.g., PRS). The gNB can measure the RSRP for the received SRS. The WTRU measures the Rx-Tx time difference for the PRS transmitted from the multiple TRPs. The WTRU can measure the RSRP for the received PRS. The Rx-Tx difference, and possibly the RSRP measured by the WTRU and gNB, is used to calculate the round-trip time. Here, "WTRU Rx-Tx time difference" refers to the difference between the arrival time of the reference signal transmitted by the TRPs and the transmission time of the reference signal transmitted from the WTRU. An example of a DL and UL positioning method is multi-cell round-trip time (multi-RTT positioning).

[0065] Artificial intelligence (AI) can be broadly defined as machine-driven behavior that simulates cognitive functions for detecting, reasoning, adapting, and acting, and provides the ability to discriminate patterns. Machine learning (ML) can refer to a type of algorithm that solves problems based on learning through experience ("data") without being explicitly programmed ("composing a set of rules"). Since machine learning can be considered a subset of AI, the term AIML is used to imply such systems. Different machine learning paradigms can be conceived based on the nature of the data or feedback available to the learning algorithm. For example, a supervised learning approach may involve learning a function that maps inputs to outputs based on labeled training examples, where each training example may be a pair consisting of an input and a corresponding output. For example, an unsupervised learning approach may involve detecting patterns in existing unlabeled data. For example, a reinforcement learning approach may involve performing a set of actions in an environment to maximize cumulative rewards. In some policies, it is possible to apply machine learning algorithms using combinations or interpolations of the approaches mentioned above. For example, a semi-supervised learning approach may use a combination of small amounts of labeled data and large amounts of unlabeled data during training. In this respect, semi-supervised learning lies between unsupervised learning (which does not have labeled training data) and supervised learning (which only has labeled training data).

[0066] Referring to Figure 2, one example of neural network 200 is shown. The goal of training is to adjust the weights by applying inputs, represented as w and x in network 200 (these may be called neuron weights or link weights), so that the output from the neural network approaches a desired target value associated with the input value. In the example in Figure 2, neural network 200 consists of three layers. During training, for a given input, the difference between the output and the desired value is calculated and used to update the weights w and / or x in neural network 200. A large difference observed between the output and the desired value is expected to result in a large change in weights, while a small difference leads to a small change in weights w and / or x.

[0067] For example, in positioning, the input may be a reference signal parameter, and the output may be an estimated position. The desired value may be point information obtained with high accuracy by a Global Navigation Satellite System (GNSS). Once the neural network 200 has completed its training (for example, the difference between the output and the desired value is below a specified threshold), the neural network 200 can be applied for positioning by supplying an input and using the output as the expected result for the associated input. The output may be the estimated position or point of the WTRU. Therefore, in order to train the neural network, it is important to identify the inputs to the neural network, the expected output associated with the input, and the actual output from the neural network to which the target value is compared. As an example, a neural network model may be characterized by the number of weights, the number of layers in the neural network, and the number of neurons per layer.

[0068] Deep learning refers to a classification of machine learning algorithms that utilize artificial neural networks (specifically deep neural networks (DNNs)) that are broadly inspired by biological systems and include at least one hidden layer. DNNs are a special classification of machine learning models inspired by the human brain, where the input is linearly transformed and passed through a nonlinear activation function multiple times. DNNs typically consist of multiple layers, each consisting of a linear transformation and a given nonlinear activation function. DNNs can be trained using training data via backpropagation algorithms. Recently, DNNs have demonstrated state-of-the-art performance in various domains, such as conversation, video, and natural language, and in various machine learning settings, including supervised, unsupervised, and semi-supervised. The terms “event” and “opportunity” may be used interchangeably in this disclosure.

[0069] As previously mentioned, the current network (e.g., a point management function (LMF) or gNB) can provide a hard or soft LOS indicator to the WTRU for each TRP resource or PRS resource. Furthermore, the WTRU can provide a hard or soft line-of-sight (LOS) indicator to the network (e.g., LMF, gNB) for each TRP resource or PRS resource. An AIML model can be trained to generate LOS indicators as labels or estimates based on inputs (e.g., measurements). LOS indicators may be generated by the WTRU or the network, and conventionally, the quality of the generated LOS indicators is not validated by the WTRU or the network. Therefore, when the network or WTRU trains an AIML model by setting an LOS indicator generated by either the WTRU or the network as a desired target, and the LOS indicator is not validated, the output of the AIML model (e.g., inference) (e.g., the inferred LOS indicator) may be unreliable. The following embodiments include aspects for improving the reliability of the LOS indicator.

[0070] In one manner, the transmission of a sounding reference signal (SRSp) for positioning may be used to verify the determined LOS indicator. For example, a WTRU is configured by the LMF with a downlink positioning reference signal (PRS) and sounding reference signal (SRS) configuration, a target transmit / receive point (TRP) and LOS indicator threshold, and a time threshold (e.g., N slots). Furthermore, the WTRU is configured by the LMF with PRS and SRS resources. In one exemplary operation, the WTRU receives a request to verify the LOS indicator for a configured target TRP, and the WTRU sends a message to the network accepting the request. The WTRU receives an SRS resource ID. The WTRU performs measurements on the received PRS and determines the LOS indicator for the target TRP. The determined LOS indicator is compared to a configured LOS indicator threshold, and if the LOS indicator is below the threshold, it transmits an SRSp associated with the indicated SRS resource ID.

[0071] In some cases, the LOS indicator may fall below the threshold, but since the WTRU has received a PRS, the WTRU cannot transmit a positioning SRS within the configured time threshold. In this case, the WTRU may report to the LMF / gNB that the verification procedure could not be completed. The WTRU reports to the network the measured values ​​(e.g., Reference Signal Received Power (RSRP)), the WTRU location, and the determined LOS indicator (based on the received PRS) associated with the target TRP.

[0072] In various embodiments, a WTRU may send a request to the network for configuration (e.g., PRS configuration, SRSp configuration) on a physical uplink sharing channel (PUSCH), a physical uplink control channel (PUCCH) as uplink control information (UCI), via the Medium Access Control Layer Control Element (MAC-CE) and / or Radio Resource Control (RRC), or as an LTE Positioning Protocol (LPP) message. The request from the WTRU may include a requested configuration of a measurement gap, a PRS processing time frame, or a time frame for transmitting SRS for positioning (SRSp).

[0073] The WTRU may transmit an acknowledgment message in PUSCH or PUCCH for a grant received from the network. The timeframes used herein may be configured by the network. The WTRU may receive multiple configurations of timeframes (e.g., time lengths), and the WTRU may determine which timeframe to activate based on activation commands associated with timeframes received from the network.

[0074] In various embodiments, multiple conditions / criteria may be used in combination. A WTRU may be configured with multiple conditions and associated WTRU behaviors, and the WTRU may decide which behavior to use based on the applicable conditions. In some examples, a WTRU may measure DL-PRS inside or outside an active bandwidth portion (BWP) and / or transmit SRSp inside or outside an active BWP. A WTRU may be pre-configured with parameters (e.g., measurement gap, RPS processing time frame, PRS configuration, SRSp configuration) via quasi-static messages (e.g., LPP, RRC). A WTRU may be configured with and according to actions / rules provided by the network, and the WTRU may decide to take associated actions.

[0075] In addition to the measurements performed on the PRS, the WTRU may include at least one of the following cell-related measurements: the synchronous signal reference signal received power (SS-RSRP) from the serving cell with the corresponding cell ID, the SS-RSRP from the neighboring cell with the corresponding cell ID, the RSRP of the CSI-RS with the channel state information reference signal (CSI-RS) resource ID, and / or the RSRP of the demodulation reference signal (DM-RS).

[0076] In this specification, the following terms have the following meanings: “Network” may include Access and Mobility Management Functions (AMF), Location Management Functions (LMF), Next Generation NodeBs (gNBs), and / or Next Generation Radio Access Networks (NG-RANs), as well as their equivalents or future related nodes / functions. “Pre-configured” and “configured” may be used interchangeably. “Non-serving gNB” and “neighboring gNB” may be used interchangeably. “gNB” and “TRP” may be used interchangeably. “PRS,” “SRS,” “SRS for positioning (SRSp),” or “SRS for positioning purposes” may be used interchangeably. “PRS” or “PRS resource” may be used interchangeably. “PRS(pl)” or “PRS resource(pl)” may be used interchangeably, and “PRS(pl)” or “PRS resource(pl)” may belong to different sets of PRS resources. “PRS” or “DL-PRS” or “DL PRS” may be used interchangeably. The "measurement gap" or "measurement gap pattern" may be used interchangeably, and the "measurement gap pattern" may include parameters such as the measurement gap time length, measurement gap repetition period, or measurement gap period. The "ID" may be used interchangeably with the "index".

[0077] A positioning reference unit (PRU) may be a WTRU or TRP whose location (e.g., altitude, latitude, geographic coordinates, or local coordinates) is known by a network (e.g., gNB, LMF). The capabilities of a PRU may be the same as those of a WTRU or TRP, for example, being able to receive PRS, transmit SRS or SRS for positioning (SRSp), return measurements, or transmit PRS. A WTRU acting as a PRU may be used by a network for calibration purposes (e.g., to correct unknown timing offsets, to correct unknown angular offsets).

[0078] LMF is an example, not limited to, of a node or entity (e.g., a network node or entity) that may be used for or to assist in positioning. Any other node or entity may be used instead of LMF, and this may not be inconsistent with the disclosure. In various embodiments, WTRU may receive pre-configured thresholds from the network (e.g., LMF, gNB).

[0079] The LOS indicator may be a hard indicator (e.g., =1, or =0) or a soft indicator (e.g., =0,0.1,0.2...,1) and indicates the probability of the existence of an LOS path between the TRP and the WTRU or along the PRS path. The LOS indicator may be associated with a TRP or PRS resource ID (e.g., an index). The WTRU may receive a LOS indicator from the network for each TRP or resource ID. Alternatively, the WTRU may determine the LOS indicator for each TRP or resource ID based on measurements. The LOS indicator is used to quantify the probability of a line of sight between the WTRU and the TRU and / or the PRS / SRSp Tx direction. The NLOS indicator is used to quantify the probability of a non-line of sight between the WTRU and the TRP and / or the PRS / SRSp Tx direction. The LOS and NLOS indicators may be used interchangeably regardless of the decision; for example, the LOS indicator may indicate an NLOS path, or vice versa. That is, indicators related to line of sight are not specific to any decision. Finally, in this specification, a WTRU location may be represented, for example, by altitude, latitude, geographic coordinates, or local coordinates.

[0080] In some embodiments, the configuration of the reference signal (RS) for positioning may include a configuration for the positioning reference signal (PRS). For example, the PRS configuration includes the following parameters: number of symbols, transmit power, number of PRS resources included in the PRS resource set, PRS muting pattern (e.g., the muting pattern can be represented via a bitmap), periodicity, type of PRS (e.g., periodic, semi-permanent, or aperiodic), slot offset for periodic transmission of the PRS, vertical shift of the PRS pattern in the frequency domain, time gap between iterations, iteration coefficient, resource element (RE) offset, comb pattern, comb size, spatial relationships, pseudo-collocation (QCL) information for the PRS (e.g., QCL target, QCL source), number of positioning reference signals (PRUs), number of TRPs, absolute radio frequency channel number (ARFCN), subcarrier spacing, expected reference signal timing difference (RSTD), uncertainty of expected RSTD, starting physical resource block (PRB), bandwidth, BWP ID, number of frequency layers, start / end times for PRS transmission, on / off indicator for PRS, TRP ID, PRS ID, cell ID, global cell ID, PRU It may include an ID and at least one of the applicable time frames. The WTRU may apply the PRS configuration on the condition that the current time falls within the applicable time frame.

[0081] In various embodiments, the RS configuration for positioning may include an SRS configuration for positioning, also known as SRSp. In one example, the SRS(SRSp) or SRS configuration for positioning may include a resource ID, a comb offset value, a cyclic shift value, a starting position in the frequency domain, a number of SRSp symbols, a shift in the frequency domain for the SRSp, a frequency hopping pattern, a type of SRSp (e.g., aperiodic, semi-persistent, or periodic), a sequence ID used to generate the SRSp, or another ID used to generate the SRSp sequence, spatial relation information indicating which reference signal (e.g., DL RS, UL RS, CSI-RS, SRS, DM-RS) or synchronization signal / SSB (e.g., SSB ID, SSB cell ID), however, SRSp and DL RS may include at least one of the following spatial information: pseudo-collocation (QCL) information (e.g., QCL relationships between SRSp and other reference or synchronization signal blocks (SSBs)), QCL types (e.g., QCL type A, QCL type B, QCL type D), resource set ID, a list of SRSp resources in the resource set, transmit power-related information, path loss reference information which may include indices for SSB, CSI-RS, or PRS, the period of the SRSp transmission, and / or spatial orientation information for the SRSp transmission (e.g., beam information, transmission angle, e.g., angle of arrival (AoD)), and spatial orientation information for DL ​​RS reception (e.g., beam ID, angle of arrival used to receive DL RS). "ID" may be used interchangeably with "index".

[0082] According to the disclosed embodiments, various measurements are used to determine positioning information. In one example, RSTD may be defined as the difference in arrival times between a PRS transmitted from a reference TRP and a PRS transmitted from a target TRP. WTRU may be constructed using a reference TRP index and a target TRP index. WTRU may also be constructed using a PRS resource index to perform the measurement, and WTRU may determine the arrival time from a TRP (reference or target) based on one or more PRS resources associated with the TRP. In another example, RSTD may be defined as the difference in arrival times between a reference PRS transmitted from a TRP and a target PRS transmitted from a TRP.

[0083] In one example, "WTRU Rx-Tx time difference" refers to the difference between the arrival time of the reference signal transmitted by the TRP and the transmission time of the reference signal transmitted from the WTRU. The WTRU Rx-Tx time difference may be associated with the PRS resource ID and / or SRSp resource ID. In another example, the WTRU may measure the RSRP or reference signal received path power (RSRPP) if there are multiple paths observed on the PRS. In yet another example, the WTRU may perform phase measurements on the PRS or on a path-by-path basis. In yet another example, the WTRU may determine the channel impulse response (CIR) or power delay profile of a channel based on measurements performed on the PRS resource transmitted from the TRP.

[0084] Aspects and benefits of the disclosed embodiments include the ability to train an AIML model using a validated LOS indicator (or validated ground truth) with a WTRU or network, thereby improving the reliability of the inferences produced by the trained AIML model.

[0085] Methods for verifying LOS indicators in various embodiments are described here. In one example, the WTRU may be configured by a network (e.g., LMF, gNB) using PRS and SRSp configurations. In addition, the WTRU may be configured by a network using PRS and SRSp resources.

[0086] As described herein, there may be two types of LOS indicators in this embodiment. One type of indicator is associated with a TRP. For example, the LOS indicator is used to indicate whether there is a line-of-sight path between the WTRU and the TRP, or the probability of such a path. The other type of LOS indicator is associated with a PRS resource. In the latter case, the LOS indicator is used to indicate whether there is a line-of-sight path along the direction in which the PRS is transmitted, or the probability of such a path. Examples are shown in Figures 3 and 4, where the left subfigure in each shows the case where the LOS indicator is associated with a TRP, and the right subfigure shows the case where the LOS indicator is associated with a PRS resource.

[0087] Referring to network diagram 300 in Figure 3, an exemplary illustration of an LOS associated with a TRP is shown in 310 (left) versus an exemplary illustration of an LOS associated with a PRS in 320 (right). In one exemplary manner, a WTRU may receive a request from the network to verify an LOS indicator or to perform a verification procedure. The LOS indicator may be generated by the WTRU based on measurements performed on the received PRS. Alternatively, the network may request the WTRU to verify an LOS indicator associated with a PRS. The WTRU may send a response to the LOS verification request. For example, the WTRU may send "yes" to the request (e.g., accept the request from the network) if the WTRU is able to perform the verification or if it receives both the PRS and SRSp configurations required for verification. The WTRU may send "no" to the request if one of the above conditions is not met.

[0088] In one embodiment, an LOS verification request may include a request to verify an LOS indicator associated with a indicated TRP, such as shown in Figure 310, or an LOS indicator associated with a indicated PRS resource, such as shown in Figure 320; a time limit for the verification procedure (e.g., the verification procedure must be completed within N hours / slots / frames / subframes / symbols from the time the WTRU receives or accepts the request from the network); and / or one or more completion conditions for the verification procedure (e.g., verification is completed when the WTRU reports measurements and LOS indicators for the requested PRS resource or TRP and transmits one or more configured SRSp). When the completion conditions are met, the WTRU determines that the verification procedure is complete. In one example, the time limit for the verification procedure may be configured by the network.

[0089] In some embodiments, the method for a WTRU may include the WTRU communicating its capability / availability for LOS indicator verification. For example, the WTRU may be configured to indicate whether it will assist in LOS indicator verification as part of a WTRU capability report. For example, the WTRU may include additional information about the WTRU's LOS indicator verification capability, including, but not limited to, the requirements described above (e.g., granularity of LOS verification, per TRP and / or per PRS), the latency of such indication (e.g., the time delay between PRS reception at the WTRU and SRSp transmission at the WTRU—potentially including the latency of LOS determination at the WTRU), time limits for verification, termination conditions, etc. In some embodiments, the timing of the WTRU capability transmission may implicitly indicate that the WTRU is ready for the LOS indicator verification procedure. Alternatively, the WTRU may transmit an indication of availability for the LOS indicator verification procedure based on one or more conditions. For example, a WTRU may be configured to send availability indications based on PRS reception status (e.g., RSRPP is above a threshold), LOS reliability is above a threshold, location and / or time, WTRU RRC status (e.g., connected), or similar factors.

[0090] According to some embodiments, the validated LOS indicator may include validation quality. In one example, the WTRU may receive an indication from the network associated with the LOS indicator, indicating that the LOS indicator is being validated. The WTRU may be configured to use the validated LOS indicator to train an AIML model by using the validated LOS indicator as the desired output of the AIML model during training. In some embodiments, validation for the LOS indicator may have validity conditions (e.g., time validity, area validity). For example, the WTRU may be configured with a time length (e.g., N days, M slots) for which validation of the LOS indicator is valid. The WTRU may be configured with start and / or end times for the validated LOS indicator. In one example, the WTRU may decide that validation is invalid after a timer for the validation procedure has expired or after the time length of the validation procedure has exceeded a limit.

[0091] In some embodiments, the quality of validation for the LOS indicator may be indicated by a hard indicator (e.g., 1 = validated, 0 = not validated). In other embodiments, validation may be indicated by a soft indicator (e.g., 1 = strongly validated, 0.5 = mildly validated, 0 = weakly validated). In some embodiments, validation may be indicated only when the LOS indicator is validated, and / or not when the TRP or PRS resource is not validated. In one example, WTRU may decide to use a validated LOS indicator for training if the validation indicator exceeds a configured threshold.

[0092] In various embodiments, the WTRU may decide to use the measurements associated with the validated LOS indicator if the validated LOS indicator is associated with a PRS resource. In another example, if the quality of validation for the LOS indicator exceeds a configured threshold, the WTRU may decide to use the measurements associated with the LOS indicator to train the AIML model. For example, if the WTRU makes measurements on a PRS resource (e.g., RSRSP, RSRPP, CIR) associated with a validated LOS indicator, the WTRU may use the measurements to train the AIML model and set the validated LOS indicator as the desired target.

[0093] In other exemplary embodiments, if a validated LOS indicator is associated with a TRP, the WTRU may decide to use the validated LOS indicator as the target output and use the measurements made for PRS transmitted from the TRP to train the AIML model. In another example, the RSTD measurement is defined based on the difference between the time of arrival (ToA) of a PRS resource transmitted from a target TRP and the ToA of a PRS resource transmitted from a reference TRP. The WTRU may use the reference signal timing difference (RSTD) as input to train the AIML model only if the LOS indicators for PRS resources associated with the target TRP and the reference TRP are validated.

[0094] Referring to Figure 4, Figure 400 shows an example of transmitting SRS along the Tx direction 410 or the Rx direction 420. In one example, the WTRU may be configured to determine an LOS indicator for a PRS resource, such that the PRS resource may be indicated by the network (e.g., LMF, gNB). In another example, the WTRU may be configured to determine an LOS indicator for a TRP indicated by the network (e.g., TRP ID or PRS ID).

[0095] In some embodiments, the WTRU may be configured to determine an LOS indicator for an SRSp resource. For example, the network may provide an SRSp resource ID, and the WTRU determines the LOS indicator associated with the SRSp resource ID. The WTRU may report the LOS indicator associated with the SRSp resource ID to the network.

[0096] In some embodiments, the WTRU may determine the LOS indicator associated with an SRSp resource ID when it receives a PRS resource that is spatially aligned or correlated with the SRSp resource ID. For example, the WTRU may receive a configuration from the network indicating that PRS resource #1 and SRSp resource #3 are spatially related, aligned, or correlated. The WTRU may perform measurements on PRS#1 resource, determine the LOS indicator for SRSp resource #3, and report it to the network.

[0097] Referring to Figure 5, in another exemplary Figure 500, the WTRU may determine the LOS indicator for an angle indicated by the network. The angle may be defined as the angle with respect to the reference TRP. As shown in Figure 5, if the WTRU is required to indicate the LOS indicator for an angle indicated by the network (Angle_d), the angle is defined with respect to geographical north (for example, in the Earth coordinate system). In Figure 5, the angle indicated from the viewpoint of the TRP (Angle_d) is different from the viewpoint of the WTRU (Angle_a).

[0098] In one example, a WTRU may determine an LOS indicator for an angle (e.g., from the viewpoint of the WTRU or TRP) or multiple LOS indicators for multiple angles. The WTRU may report the determined LOS indicators for an angle to the network. In one example, a WTRU may be configured with a range of angles for making measurements against a configured DL-RS (e.g., a PRS). In another example, the network may request the WTRU to report LOS indicators within that range of angles (e.g., up to N angles, each associated with an LOS indicator). In yet another example, the WTRU may be configured with multiple PRS resources to make and report measurements on the LOS indicators associated with angles. The WTRU may decide to associate an LOS indicator with an angle if the indicator is below or above a configured threshold.

[0099] The WTRU may be configured to show LOS indicators for angles within a configured range, and may be configured with the maximum number of angles to be associated with the LOS indicator, for example, N angles. The WTRU may be configured to report up to N angles within the configured range. In some examples, the WTRU may be configured with the granularity of the angles for the associated LOS indicators, where examples of granularity may be 10 degrees, 1 degree, 0.1 degrees, and 0.01 degrees.

[0100] For example, a WTRU may report LOS indicators for each configured angular range (e.g., [30 to 60 degrees] from the WTRU's viewpoint with respect to geographical north). A WTRU may be configured by the network using an angular range, and may receive a request from the network to report LOS indicators for the configured angular range. The angles may be defined according to the viewpoint of the TRP or the WTRU, as in the example shown in Figure 5. Based on measurements of the configured PRS resources, the WTRU may decide to report LOS indicators for each configured angular range.

[0101] Exemplary SRSp transmission conditions are described here. In one embodiment, a WTRU may decide to verify an LOS indicator associated with a PRS or TRP by transmitting a configured SRSp when at least one or a combination of the following exemplary conditions are met.

[0102] (1) The determined LOS indicator may be below the threshold (for example, the LOS indicator is 0.4 and the threshold is 0.7).

[0103] (2) The WTRU receives an LOS indicator from the network that is associated with a PRS resource or TRP. When the LOS indicator is above a threshold, the WTRU measures multiple paths in the measurement (for example, multiple ToA, AoA for the PRS resource that the WTRU is measuring).

[0104] (3) The RSRP or RSRPP of the first route to the indicated PRS resource is below the threshold.

[0105] (4) If the uncertainty, variance, standard deviation, or higher-order moment (e.g., skewness, kurtosis) in the measured value (e.g., RSTD, RSRP, RSRPP, ToA, AoA, CIR) is above a threshold, the WTRU is constructed using the time frame or duration of the measurement for which the WTRU determines the uncertainty.

[0106] (5) The uncertainty, variance, or standard deviation in the determined LOS indicator (e.g., a hard or soft LOS indicator) is above a threshold, and the WTRU is constructed using the time frame or duration of the measurement for which the WTRU determines the uncertainty.

[0107] (6) The difference between the Rx direction (e.g., in degrees) and the Tx direction (e.g., in degrees) of the PRS exceeds the configured threshold. The WTRU may receive information about the AoD (angle of departure) for each PRS from the network. The AoD may be associated with the PRS resource ID. The WTRU may determine the AoA (angle of arrival) for each PRS and calculate the difference between the AoD and the AoA. The WTRU may transform the AoA using a configured function (e.g., AoA - 180 degrees) such that the difference between the AoD and the transformed AoA is calculated based on the same criterion. Referring to FIG. 6, an example 600 where the Tx angle and the Rx angle are different is shown. In the example 600 shown, the PRS transmitted from the TRP is reflected by an object 610 and received by the WTRU 620.

[0108] (7) Within the range of angles configured by the network, the WTRU determines the LOS indicator for at least one of the angles.

[0109] (8) For a given LOS indicator value, whether the measurements performed on the PRS exceed or fall below a threshold (e.g., the number of paths). For example, if the LOS indicator is 0.9 and the number of paths observed in the measurement (e.g., ToA) exceeds the threshold (e.g., 4), the WTRU determines to verify the LOS indicator (e.g., by transmitting a configured SRSp). In one example, the WTRU may be configured using an association table, where, for example, the range of LOS indicator values is associated with a threshold for the channel characteristic (e.g., the number of paths). In one example, the configured range may be 0.2 < LOS indicator ≤ 0.4 (where "≤" indicates "less than or equal to"), the threshold for the number of paths is 4, and the WTRU transmits an SRSp when the number of paths is less than the threshold and the LOS indicator is within the range.

[0110] (9) The WTRU determines the LOS indicator for the angle requested by the network.

[0111] Any of the above conditions may also be applicable to the WTRU's decision on whether a verification procedure should be initiated. For example, if at least one of the above conditions is met, the WTRU may decide to initiate a LOS verification procedure.

[0112] Embodiments for positioning using a verified LOS indicator may be subject to hard or soft indicators. In one example, the WTRU may be configured by the network to determine hard indicators. In another example, the WTRU may be configured by the network to determine soft indicators. In one embodiment, for example, the WTRU may be configured to indicate hard or soft indicators (e.g., =1 or =0, LOS or NLOS) and soft indicators (e.g., =0, 0.1, ..., 0.9, 1). Based on measurements made for a received PRS, the WTRU may decide to report hard indicators associated with an indicated PRS resource or indicated TRP. The WTRU may decide to associate a hard indicator with a configured PRS or TRP if at least one of the configured PRS resources for measurement is below a threshold, or if the number of paths measured for a PRS resource is below a threshold.

[0113] Alternatively, the WTRU may decide to associate a soft indicator with a configured PRS or TRP if at least one of the following conditions is met: (i) the number of configured PRS resources for measurement is above a threshold, (ii) the number of routes measured for a PRS resource is above a threshold, or (iii) the number of routes measured for a PRS resource is below a threshold. If the WTRU determines that the hard indicator associated with a PRS or TRP is 0 (e.g., NLOS), the WTRU may decide to transmit a configured SRSp.

[0114] In some embodiments, an SRSp transmission may be an implicit indication of an LOS indicator based on SRSp resource selection. For example, a WTRU may be configured to determine one or more parameters of an SRSp transmission depending on the LOS status of the received PRS. In one example, the WTRU may be configured with a first SRSp resource / configuration and a second SRSp resource / configuration, the first SRSp configuration may be associated with a first SRS sequence ID, and the second SRSp configuration may be associated with a second sequence ID. In another example, the first SRSp configuration may be associated with a first freqDomainPosition and / or freqDomainShift and / or cyclic shift and / or resource mapping and / or comb offset or similar configuration, and the second SRSp configuration may be associated with a second freqDomainPosition and / or freqDomainShift and / or cyclic shift and / or resource mapping and / or comb offset or similar configuration. In one example, a WTRU may be configured using associations between first and second SRSp resources / configurations and PRS resources / configurations. The WTRU may be configured to receive PRSs and determine the LOS status / indicator associated with the PRS. If the LOS indicator is above a threshold, the WTRU may transmit using the first SRSp resource / configuration. If the LOS indicator is below a pre-configured threshold, the WTRU may transmit an SRS using the second SRSp resource / configuration.

[0115] In another example, if the hard LOS indicator is = 1, the WTRU may transmit using the first SRSp resource / configuration. If the hard LOS indicator is = 0, the WTRU may transmit the SRS using the second SRSp resource / configuration.

[0116] According to some embodiments, timeframes may be used to track changes in the LOS indicator. In one example, a WTRU may be configured by the network using timeframes to verify the LOS indicator associated with a PRS or TRP. While the timeframe is active (e.g., enabled by a MAC-CE command), the WTRU may receive periodic PRSs. Based on measurements made on the received PRSs, the WTRU may determine the LOS indicator for each PRS. The WTRU may transmit configured SRSp for verification during the configured timeframe. The WTRU may report the determined LOS indicator and transmit configured SRSp until the timeframe is closed or disabled. In one example, the timeframe may be characterized by a start time (e.g., expressed as absolute time, or relative time with respect to an indicated or configured reference time), an end time, and / or a duration (e.g., expressed as seconds, number of slots, number of frames, number of subframes, or number of symbols).

[0117] The behavior of SRSp transmissions in several exemplary embodiments is described here. In one example, the WTRU may receive a configuration associating PRSs with SRSs. The WTRU may receive a table associating one PRS resource ID with multiple SRSp resource IDs. In another example, the WTRU may receive a table associating multiple PRS resource IDs with one SRSp resource ID. The WTRU may decide to transmit the SRSp associated with the PRS if it decides to verify the LOS indicator associated with the received PRS. If there are multiple SRSps associated with the PRS, the WTRU may be configured to determine the order of transmissions according to configured rules (for example, transmitting from the SRSp with the lowest SRSp resource ID).

[0118] In another example, a WTRU might receive a configuration associating a TRP with an SRS. The WTRU might receive a table associating a TRP ID (e.g., a PRS ID) with multiple SRSp resource IDs. If the WTRU decides to verify the LOS indicator associated with the TRP, it might decide to send the SRSp associated with the TRP.

[0119] In the examples described herein, the WTRU may receive an indication showing a PRS resource ID for referencing the PRS. The WTRU may also receive configurations (e.g., iteration coefficients) for the configured PRS and SRSp.

[0120] In one embodiment, the WTRU may decide to transmit an SRSp based on an SRSp resource ID indicated in a quasi-static message (e.g., LPP, RRC) received from the network. In another example, the WTRU may be configured with a Tx direction that specifies the direction in which the indicated SRSp should be transmitted. The Tx direction may be indicated by referring to another UL RS (e.g., SRS, DMRS, Phase-Tracking Reference Signal (PTRS), DL RS (e.g., CSI-RS, PTRS, TRS, DMRS, PRS) or an angle (e.g., the angle is defined with respect to geographical north)).

[0121] In one example, a WTRU may be given a time frame or time limit during which it is expected to send an SRSp associated with an SRSp resource ID indicated in a quasi-static message (e.g., LPP, RRC). The time frame may begin when the WTRU receives a PRS associated with the time frame, and the length of the time frame may be expressed in terms of a number of symbols, slots, frames, subframes, etc.

[0122] Referring to Figure 7, an exemplary Figure 700 is shown in which a WTRU may be configured to transmit N SRSp that are spatially adjacent to the reference RS (e.g., SRSp, PRS) in the direction and / or the reference RS. For example, a WTRU may be configured with a reference RS such as SRSp resource #3. The WTRU may be configured to transmit N=2 SRSp that are spatially adjacent to SRS#3. Figure 7 shows that the WTRU is configured with reference SRS#3 (center), and the SRS adjacent to the reference SRS are SRS#2 and SRS#4. The WTRU may receive SRS resource IDs associated with SRS#2, SRS#3, and SRS#4.

[0123] In one embodiment, the WTRU may decide to transmit an SRSp in the Rx direction from which the WTRU received a PRS. In this case, before transmitting the SRSp, the WTRU may report the expected range of the Rx direction relative to the TRP from the viewpoint of the TRP. In another example, the WTRU may be configured to transmit an SRS associated with a PRS after the reception of a PRS. In one example, the WTRU may decide to transmit an SRS after the reception of a PRS, where the resource ID of the SRS is associated with the resource ID of the received PRS. The WTRU may be configured with a set of PRS reception and SRSp transmission configurations, such that each set includes a PRS configuration and an SRSp configuration (e.g., PRS resource ID, SRSp resource ID).

[0124] A WTRU may be configured to transmit an SRSp after it has received a PRS in a set. A WTRU may be configured with multiple sets of PRS receiving and SRS transmitting configurations. Referring to Figure 8, an exemplary Figure 800 is shown in which a WTRU is configured with three sets of PRS receiving and SRSp transmitting configurations. In the first set, the WTRU is configured to receive PRS#1 and transmit SRS#1, where the WTRU receives PRS#1 and the network resource ID associated with SRS#1. In the second set, the WTRU is configured to receive PRS#2 and transmit SRS#2. In the third set, the WTRU is configured to receive PRS#3 and transmit SRS#3. In Example 800, it is assumed that each SRS or PRS corresponds to a different Tx direction.

[0125] In one example, a WTRU may be configured with a set of PRS receive and SRSp transmit, where the PRS and SRSp resources are associated in the configuration. In Example 800 of Figure 8, the WTRU may receive a configuration or indication in which PRS#1 and SRS#1 are associated (for example, PRS resource #1 and SRS resource #1 are associated), PRS#2 and SRS#2 are associated, and PRS#3 and SRS#3 are associated.

[0126] In one embodiment, the WTRU may be configured with multiple sets of PRS reception and SRSp transmission, where different SRSp resource IDs are configured with the same PRS resource ID. In Example 800 of Figure 8, in the first set, the WTRU is configured to receive PRS#1 and transmit SRS#1. In the second set, the WTRU is configured to receive PRS#2 and transmit SRS#2. Finally, in the third set, the WTRU is configured to receive PRS#3 and transmit SRS#3. In a different example, in the first set, the WTRU is configured to receive PRS#1 and transmit SRS#1. In the second set, the WTRU is configured to receive PRS#2 and transmit SRS#1. Finally, in the third set, the WTRU is configured to receive PRS#3 and transmit SRS#1.

[0127] Referring to Figure 9, an exemplary network diagram 900 is shown for an embodiment of SRS transmission after receiving a set of PRSs during a time frame. In one example, a WTRU may be configured to transmit a set of SRSs after receiving a set of PRSs from the network. In the example shown in Figure 9, the WTRU is configured to receive PRS#1, PRS#2, and PRS#3 and to make measurements for each PRS. After the WTRU receives the configured PRSs, the WTRU is configured to transmit SRS#1, SRS#2, and SRS#3. After the WTRU transmits the SRSs, the WTRU returns the measurements to determine the LOS indicator.

[0128] In the example above, at each transmission opportunity (for example, when WTRU transmits SRS#1), WTRU may be configured with an iteration factor (N), where WTRU is expected to transmit SRS N times. For example, if one SRSp transmission consists of 12 symbols in a slot, and WTRU is configured with an iteration factor N=4, WTRU may transmit 12-symbol SRSs in 4 slots, each slot containing 12-symbol SRSs.

[0129] In one example, a WTRU may be configured or requested by the network to transmit SRSp configured within a range of transmit or receive angles (e.g., from the WTRU's perspective or the TRP's perspective, as shown in Figure 5 and discussed previously). In another example, a WTRU may transmit configured SRSp at angles requested or configured by the network. A WTRU may decide which SRSp to transmit based on the spatial relationship of the SRSp with DL-RS (e.g., CSI-RS or PRS) or UL-RS (e.g., SRS, SRSp, PTRS, DMRS). Based on the spatial relationship, a WTRU may determine whether the transmit angle of an SRSp is within the configured angle range. If there are multiple SRSp to transmit, a WTRU may determine the order of SRSp transmissions according to the SRSp resource ID associated with the SRSp (e.g., transmitting each SRSp from the lowest ID up to the highest ID). A WTRU may be configured with the maximum number of SRSp to transmit (e.g., N). The WTRU may decide to prioritize SRSp transmissions along an angle, where the angle is associated with the top N LOS indicators.

[0130] In some embodiments, if the WTRU is configured to report an LOS indicator within a range of angles or a specific angle, the WTRU may decide to transmit an SRSp along the angle in which the WTRU determined the LOS indicator. The WTRU may decide to transmit an SRSp along the angle if the difference between the transmission angle and the angle associated with the LOS indicator is within a threshold.

[0131] Figure 10 shows an example of the spatial relationship between SRS and CSI-RS. In the illustrative Figure 1000, SRS#1 and CSI-RS#1 are spatially related because their transmission directions are spatially aligned. However, SRS#1 and CSI-RS#2 are not spatially related because their transmission directions are spatially misaligned.

[0132] In some embodiments, the RS may have spatial relation information, for example, multiple SRSp may be spatially related to a single PRS. This may be due to different beamwidths of DL or UL transmissions. If multiple SRSp may be spatially related to a PRS, and the WTRU decides to transmit an SRSp to verify the LOS indicator associated with the PRS (for example, if the LOS indicator generated by the WTRU or network is below a configured threshold), the WTRU may decide to transmit the SRSp in a configured order (for example, starting with the transmission of the SRSp with the lowest resource index or ID).

[0133] Referring to Figure 11, a spatial diagram 1100 is shown with two examples 1110 and 1120 of spatially related RSs. In the left subdivision 1110, PRS#2 is spatially related to SRS#1 and SRS#2, both of which have relatively wide beamwidths compared to the beamwidth of PRS#2. In the right subdivision 1120 of Figure 11, PRS#2 is spatially related to SRS#1 and SRS#2, both of which have relatively narrow beamwidths compared to the beamwidth of PRS#2. If the WTRU decides to validate the LOS indicator it has generated for PRS#2, the WTRU may decide to transmit SRSp in order from the lowest SRSp resource index to the highest SRSp resource index, for example, the WTRU transmits SRS#1 first and then SRS#2 second.

[0134] Examples of verification procedure failures are described here. In one example, after the WTRU accepts a request to verify an LOS indicator transmitted from the network, it may not be able to receive the PRS and / or process the measurement due to the lower priority of receiving the PRS (for example, the WTRU decides to receive it on a PDSCH, which is associated with a higher priority than receiving / measuring the PRS). In another example, after the WTRU accepts a request to verify an LOS indicator, it may not be able to transmit an SRSp due to the lower priority of LOS indicator verification using an SRSp (for example, the WTRU decides to transmit it on a Physical Uplink Control Channel (PUCCH), which is associated with a higher priority than transmitting the SRSp).

[0135] Referring to Figure 12, network diagram 1200 shows one exemplary embodiment of a possible LOS indicator verification failure. As shown in Figure 1200, the WTRU is configured to transmit an SRSp 1205 within a specific time frame 1210. For example, if the WTRU may not be able to transmit an SRSp 1205 within a specified / configured time limit 1210, e.g., within a certain time threshold from when the WTRU receives a PRS, an LOS indicator verification failure may occur. The inability to transmit an SRSp 1205 within a given time frame 1210 could be due to a variety of reasons, including that transmitting an SRSp has a lower priority than other actions. For example, the WTRU may decide to transmit on a PUCCH during the time frame, which has a higher priority than transmitting an SRSp. An example of a time limit or time frame 1210 for sending a given SRSp is shown in Figure 12, where the WTRU is configured with a time threshold (T) (e.g., T seconds, T symbols, T subframes, T slots) within which the verification SRSp 1205 should be sent. Figure 12 shows the actual transmission of the SRSp 1205 within the time frame (T) 1210, but if the WTRU is unable to send the SRSp 1205 within the time limit T1210, the WTRU declares failure in the verification procedure.

[0136] In various cases, a WTRU may determine that the duration of an LOS indicator verification procedure exceeds a threshold time or time frame due to a delay in receiving a PRS or a delay in transmitting an SRS. In another case, a WTRU may be unable to transmit an SRSp within the time limit or time frame from receiving a PRS because it failed to acquire UL resources for transmitting an SRSp. If a WTRU is unable to complete one or more LOS indicator verification procedures, it may report to the LMF (or other relevant function or node) that it was unable to complete the LOS indicator verification procedures. In some embodiments, an LOS indicator verification procedure may be repeated if it has previously failed, been terminated, or canceled.

[0137] Reporting content for various embodiments is described here. According to some embodiments, the WTRU decides to report to the network a measurement (e.g., RSTD) associated with the determined LOS indicator. The WTRU may perform measurements for each configured PRS to determine the LOS indicator. For example, the WTRU may perform measurements for each configured PRS to determine the LOS indicator for a target TRP. According to one embodiment, if the WTRU is configured with multiple sets of PRS receiving and SRSp transmission configurations and the WTRU is configured or required to report the LOS indicator for each PRS, the WTRU may decide to report to the network the measurement (e.g., RSTD, RSRP, RSRPP) associated with the received PRS and the LOS indicator after or before the WTRU transmits an SRSp for each set for LOS indicator verification. In one example, the WTRU may include a timestamp in the report, where the timestamp may be expressed in terms of absolute time, relative time with respect to an indicated or configured reference time, SFN, frame index, symbol index, slot index, and / or subframe index.

[0138] In another example, if a WTRU is configured with multiple sets of PRS reception and SRSp transmission configurations, and the WTRU is configured or required to report an LOS indicator for an indicated TRP, the WTRU may report a measured value and / or determined LOS indicator associated with the indicated TRP after the last configured set of PRS reception and SRSp transmission (for example, in the example of Figure 8 discussed earlier, the WTRU reports a measured value and / or LOS indicator for the target TRP only after the WTRU has received PRS#3 and transmitted SRS#3).

[0139] In some embodiments, the WTRU may implicitly indicate the LOS verification status (e.g., a hard or soft indicator). For example, the WTRU may be configured with SRS parameters (e.g., an SRS sequence or SRS sequence ID) or configurations that the WTRU should use for the LOS or NLOS indicator.

[0140] Referring to Figure 13, a method 1300 for verifying a LOS indicator for positioning information is shown according to one exemplary embodiment. Method 1300 may generally begin with configuring a WTRU (1305), i.e., the WTRU receives configuration information with PRS and SRS configuration by an LMF (or other similar function or node). The WTRU is also configured by the LMF with PRS and SRS resources (1305). The WTRU receives a PRS transmitted by a TRP (1310), and the angle of departure (AoD) of the transmitted PRS is indicated to the WTRU. The PRS is received by the WTRU at the angle of arrival (AoA) (1310). For example, when the WTRU receives a request to verify a LOS indicator for a configured target TRP (1315), the WTRU receives a transmit (Tx) direction with AoD for transmitting a subsequent SRSp using the resources indicated from the network (1320). The WTRU performs measurements on the received PRS, including AoA (1325), to determine the LOS indicator relative to the target TRP. If the difference between the indicated AoD of the PRS and the measured AoA of the PRS is greater than a threshold (1330), the WTRU transmits an SRSp at the indicated AoD (1335). If the difference is less than a threshold (1330), the WTRU may or may not transmit an SRSp at the measured angle of arrival of the PRS (1345). This decision may help reduce errors due to PRS reflections. In various embodiments, the WTRU may report the measured values ​​(e.g., RSRP), the WTRU location, and the determined LOS indicator (based on the received PRS) to the network (1350).

[0141] Referring to Figure 14, according to another method 1400, the WTRU may be configured by the LMF or other network node / function using a PRS and SRS configuration similar to the previous embodiment (1405). In this embodiment, the configuration information may include a target TRP, an LOS indicator threshold, and a time threshold (e.g., N slots). The WTRU is also configured by the LMF / network node using PRS and SRS resources (1405).

[0142] The WTRU receives a request to verify the LOS indicator for the configured target TRP (1405). In some embodiments, the WTRU may send a message to the network accepting the request or acknowledging the LOS indicator verification request (1415). The WTRU receives the SRS resource ID and, upon receiving the PRS, performs measurements on the PRS (1420) to determine the LOS indicator for the target TRP. In this embodiment, if the determined LOS indicator is below a configured threshold (1425) and the WTRU can send an SRSp within a configured time after receiving the PRS (1430), the WTRU sends an SRSp associated with the indicated SRS resource ID (1435).

[0143] If the LOS indicator is below a threshold (1425), but the WTRU is unable to transmit an SRSp within a time threshold (1430), the WTRU may report to the LMF that the verification procedure cannot be completed (1440). In some embodiments, if the WTRU determines or measures that the LOS indicator is above a threshold (1425), transmission of an SRSp may not be required or desired. In various embodiments, the WTRU may report to the network the measured value (e.g., RSRP), the WTRU location, and / or the determined LOS indicator (based on the received PRS) associated with the target TRP (1450). Embodiments disclosed herein are intended to combine steps or features of other embodiments, to perform steps in any order, or to omit features or steps.

[0144] While features and elements have been described above in specific combinations, those skilled in the art will understand that each feature or element may be used alone or in any combination with other features and elements. In addition, the methods described herein may be implemented in computer programs, software, or firmware embedded on computer-readable media 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, read-only memory (ROM), random access memory (RAM), registers, 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 multi-purpose disks (DVDs). A processor may be used in conjunction with software to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A method for a wireless transmit / receive unit (WTRU), Receiving configuration information from the network for line-of-sight (LOS) indicator verification, including positioning reference signal (PRS) and sounding reference signal (SRSp) configurations, thresholds, and associated time windows, Receiving a request to verify the LOS indicator and the SRS resource ID associated with the SRSp configuration from the network, The PRS associated with the aforementioned SRSp configuration is received from the target transmit / receive point (TRP), Measuring one or more characteristics of the PRS and determining the associated LOS indicator, The determined LOS indicator is compared with the configured threshold, When the determined LOS indicator is below the configured threshold, a sounding reference signal (SRSp) associated with the SRS resource ID is transmitted within the configured associated time window from the reception of the PRS. Methods that include...

2. The method according to claim 1, further comprising reporting the measured one or more characteristics and the determined LOS indicator to the network.

3. The method according to claim 1, further comprising reporting to the network that the LOS verification procedure cannot be completed when the SRSp cannot be transmitted within the configured associated time window.

4. The method according to claim 1, wherein if the difference between the indicated launch angle (AoD) of the PRS and the measured arrival angle (AoA) of the PRS is greater than a configured angle threshold, the SRSp is transmitted in the direction of AoA as indicated in the request to verify the LOS indicator.

5. The method according to claim 1, wherein if the difference between the indicated launch angle (AoD) of the PRS and the measured arrival angle (AoA) of the PRS is below a configured angle threshold, the SRSp is transmitted to the PRS in the direction of the measured AoA.

6. The method according to claim 2, wherein the reported LOS indicator includes a hard or soft indicator.

7. The method according to claim 2, wherein the reporting includes the received PRS measurement, WTRU position, and the determined LOS indicator.

8. The method according to claim 1, further comprising training an artificial intelligence machine learning (AIML) model using one or more validated LOS indicators.

9. A wireless transmit / receive unit (WTRU) comprising a transceiver and a processor communicatively coupled to the transceiver, wherein the transceiver and the processor are Configuration information for line-of-sight (LOS) indicator verification, including positioning reference signal (PRS) and sounding reference signal (SRSp) configurations, thresholds, and associated time windows, is received from the network. The system receives a request to verify the LOS indicator and the SRS resource ID associated with the SRSp configuration from the network. The PRS associated with the aforementioned SRSp configuration is received from the target transmit / receive point (TRP). Measure one or more characteristics of the PRS and determine the associated LOS indicator. The determined LOS indicator is compared with the configured threshold, When the determined LOS indicator falls below the configured threshold, a sounding reference signal (SRSp) associated with the SRS resource ID is transmitted within the configured associated time window from the reception of the PRS. WTRU is configured in this way.

10. The transceiver and processor are, The WTRU according to claim 9, further configured to report the measured one or more characteristics and the determined LOS indicator to the network.

11. The transceiver and processor are, The WTRU according to claim 9, further configured to report to the network that the LOS verification procedure cannot be completed when the SRSp cannot be transmitted within the configured associated time window.

12. The WTRU according to claim 9, wherein if the difference between the indicated launch angle (AoD) of the PRS and the measured arrival angle (AoA) of the PRS is greater than a configured angle threshold, the SRSp is transmitted in the direction of AoA as indicated in the request to verify the LOS indicator.

13. The WTRU according to claim 9, wherein if the difference between the indicated launch angle (AoD) of the PRS and the measured arrival angle (AoA) of the PRS is below a configured angle threshold, the SRSp is transmitted to the PRS in the direction of the measured AoA.

14. The WTRU according to claim 10, wherein the reported LOS indicator includes a hard or soft indicator.

15. The WTRU according to claim 10, wherein the reporting includes the received PRS measurement, the WTRU position, and the determined LOS indicator.

16. The WTRU according to claim 9, further comprising training an artificial intelligence machine learning (AIML) model using one or more validated LOS indicators.

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