Positioning in wireless system

Abstract

To disclose a system, a method, and means relating to positioning in a wireless system.SOLUTION: Features may be implemented, for example, in wireless transmit / receive unit (WTRU) behavior for measurement reporting during multi-beam channel scanning, in WTRU behavior during measurement reporting in the presence of a multipath, and / or in WTRU behavior during reporting to obtain correction information from a network. The WTRU can receive PRS transmissions via multiple paths. The WTRU can report the reception of the PRS transmissions via the multiple paths and Rx-Tx time difference associated with each SRSp transmission associated with each path.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 091,005, filed October 13, 2020, U.S. Provisional Patent Application No. 63 / 136,436, filed January 12, 2021, U.S. Provisional Patent Application No. 63 / 185,729, filed May 7, 2021, and U.S. Provisional Patent Application No. 63 / 228,945, filed August 3, 2021, the disclosures of which are incorporated herein by reference in their entireties. [Background technology]

[0002] Mobile communications using wireless communications continue to evolve. The fifth generation of mobile communications radio access technology (RAT) may be referred to as 5G new radio (NR). A previous (traditional) generation of mobile communications RAT may be, for example, fourth generation (4G) long term evolution (LTE). Wireless communication devices may establish communications with other devices and data networks through an access network, such as, for example, a radio access network (RAN). Summary of the Invention

[0003] Disclosed herein are systems, methods, and means related to positioning in wireless systems. Features may be implemented, for example, in wireless transmit / receive unit (WTRU) behavior for measurement reporting during multi-beam channel scanning, in WTRU behavior during measurement reporting in the presence of multipath, and / or in WTRU behavior during reporting to obtain correction information from the network.

[0004] The WTRU may receive positioning reference signal (PRS) transmissions via multiple paths. The WTRU may report the reception of the PRS transmissions via the multiple paths and the Rx-Tx time difference associated with each SRSp transmission associated with each path. This may assist in determining the RTT.

[0005] The WTRU may receive information indicating resources associated with PRS transmissions, where the PRS transmissions may have an identifier. The information may include instructions for associating a respective PRS path ID with a respective SRSp resource. The WTRU may receive information indicating resources associated with sounding reference signal for positioning (SRSp) transmissions, where the SRSp transmissions may have an identifier. The information may include a respective spatial relationship for each SRSp. The spatial relationship may include a downlink (DL) reference signal (RS) associated with a receive (Rx) direction / beam.

[0006] A WTRU may receive positioning reference signal (PRS) transmissions via multiple paths. When the WTRU receives PRS transmissions via multiple paths, a respective path ID may be assigned to each path by the WTRU. For example, a first path may be assigned Path ID 1, and a second path may be assigned Path ID 2. The WTRU may associate the first path (e.g., assigned Path ID 1) with a first SRSp (e.g., associated with SRSp identifier 2). The first path may be associated with the first SRSp based on the first path direction and a first SRSp spatial relationship associated with the first path direction. The first SRSp spatial relationship may be received from a network entity. The WTRU may associate the second path (e.g., assigned Path ID 2) with a second SRSp (e.g., associated with SRSp identifier 1). The second path may be associated with a second SRSp based on the second path direction and a second SRSp spatial relationship associated with the second path direction. The second SRSp spatial relationship may be received from a network entity.

[0007] The WTRU may send an association indication to a network entity (e.g., an LMF or a gNB). The WTRU may transmit a first SRSp over a first SRSp resource (e.g., associated with SRSp identifier 1 associated with a second path assigned Path ID 2) and may transmit a second SRSp over a second SRSp resource (e.g., associated with SRSp identifier 2 associated with the first path assigned Path ID 1). The WTRU may determine a first receive-transmit (Rx-Tx) time difference associated with the first path. The first Rx-Tx time difference may be the time difference from the time the PRS is received over the first path to the time the first SRSp (e.g., associated with SRSp identifier 2) is transmitted. A second Rx-Tx time difference associated with the second path may be determined. The second Rx-Tx time difference may be the time difference from the time the PRS was received over the second path to the time the second SRSp (e.g., associated with SRSp identifier 1) was transmitted. An indication of the first and second Rx-Tx time differences may be sent to a network entity (e.g., the LMF or the gNB). [Brief explanation of the drawings]

[0008] [Figure 1A] FIG. 1 is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] 1B is a system diagram illustrating an exemplary wireless transmit / receive unit (WTRU) that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 1C] 1B is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 1D] 1B is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 2]An example of multipath during positioning is illustrated. [Figure 3] 1 illustrates an example for receiving standalone assistance information for a DL positioning method. [Figure 4] 1 illustrates an example of receiving standalone assistance information for DL ​​and UL positioning methods. [Figure 5] 10 illustrates exemplary values ​​for WTRU receive-transmit (Rx-Tx) time difference. [Figure 6] 1 illustrates an example of a spatial relationship configuration in which a PRS may be associated with an SRSp. [Figure 7] An example of determining the Rx-Tx difference will be illustrated. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1A is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. Communication system 100 may be a multiple-access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. Communication system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), etc.

[0010] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RANs 104 / 113, CNs 106 / 115, public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or “STA,” may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular 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), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain contexts), consumer electronics devices, devices operating in commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be referred to interchangeably as a UE.

[0011] The communications system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communications networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a Base Transceiver Station (BTS), a Node B, an Encoder B, a Home Node B, a Home eNodeB, a gNB, an NR Node B, a site controller, an Access Point (AP), a wireless router, etc. Although the base stations 114a, 114b are each shown as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0012] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. The base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage for a particular geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell, for example, using beamforming to transmit and / or receive signals in desired spatial directions.

[0013] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0014] More specifically, as noted above, the communications system 100 may be a multiple-access system and may use one or more channel access schemes, such as, for example, CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114 a and the WTRUs 102 a, 102 b, 102 c in the RAN 104 / 113 may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communications 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 Packet Access (HSUPA).

[0015] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-Advanced, LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0016] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using New Radio (NR).

[0017] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may jointly implement LTE radio access and NR radio access, e.g., using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0018] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity, WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access, WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), or the like.

[0019] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point and may utilize any suitable RAT to facilitate wireless connectivity in a local area such as a location such as a business, a home, a vehicle, a campus, an industrial facility, an air 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 radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may establish a picocell or a femtocell using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). 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 need to access the Internet 110 through the CN 106 / 115.

[0020] The RAN 104 / 113 may communicate with the CN 106 / 115, which may be any type of network configured to provide voice, data, application, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1A , it will be understood that the RAN 104 / 113 and / or the CN 106 / 115 may communicate directly or indirectly with other RANs employing the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also communicate with another RAN (not shown) employing GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0021] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a public switched telephone network providing plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP), and / or the internet protocol (IP) of the TCP / IP Internet protocol suite. The network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0022] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links.) For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a that may use a cellular-based wireless technology and a base station 114b that may use an IEEE 802 wireless technology.

[0023] 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 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 source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0024] The processor 118 may be a general-purpose processor, a special-purpose 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) circuit, 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 functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0025] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0026] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may use MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0027] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0028] The processor 118 of the WTRU 102 may be coupled to and may receive user-entered data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. Additionally, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, etc. In other embodiments, the processor 118 may access information from and store data in memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0029] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components within the WTRU 102. The power source 134 may be any suitable device for providing power to the WTRU 102. For example, the power source 134 may include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0030] 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) regarding the current location of the WTRU 102. In addition to or instead of information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by any suitable location-determination method while remaining consistent with an embodiment.

[0031] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an 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 modulated (FM) radio unit, a digital music player, a media player, a video game player module, an internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, etc. The peripheral device 138 may include one or more sensors, which may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0032] The WTRU 102 may include a full-duplex radio where transmission and reception of some or all of the signals (e.g., associated with a particular subframe for both the UL (e.g., for transmission) and downlink (e.g., for reception)) may be parallel and / or simultaneous. The full-duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference through hardware (e.g., chokes) or processor-based signal processing (e.g., via a separate processor (not shown) or processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for transmission and reception of either some or all of the signals (e.g., associated with a particular subframe for either the UL (e.g., for transmission) or downlink (e.g., for reception)).

[0033] 1C is a system diagram illustrating the RAN 104 and the CN 106 according to one embodiment. As mentioned above, the RAN 104 may communicate with the WTRUs 102a, 102b, 102c over the air interface 116 using E-UTRA radio technology. The RAN 104 may also communicate with the CN 106.

[0034] The RAN 104 may include eNodeBs 160a, 160b, and 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 160a, 160b, and 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In an embodiment, the eNodeBs 160a, 160b, and 160c may implement MIMO technology. Thus, the eNodeB 160a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0035] Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, user scheduling, etc. in the UL and / or DL. As shown in FIG. 1C, the eNodeBs 160a, 160b, 160c may communicate with each other via an X2 interface.

[0036] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. Although each of the foregoing elements is illustrated as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0037] The MME 162 may be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via an S1 interface and may function as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies such as GSM and / or WCDMA.

[0038] The SGW 164 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-eNode-B handovers, triggering paging when DL data is available to the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0039] The SGW 164 may be connected to a PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0040] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional landline communications devices. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0041] Although the WTRU is depicted in FIGS. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments, such a terminal may use a wired communication interface (e.g., temporarily or permanently) with the communication network.

[0042] In a representative embodiment, the other network 112 may be a WLAN.

[0043] A WLAN in infrastructure Basic Service Set (BSS) mode may have an access point (AP) of the BSS and one or more stations (STAs) associated with the AP. The AP may have access or interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic originating from outside the BSS to a STA may arrive through the AP and be delivered to the STA. Traffic originating from a STA to a destination outside the BSS may be sent to the AP and transmitted to the respective destination. Traffic between STAs within the BSS may be transmitted, for example, through the AP; the source STA may send traffic to the AP, which may deliver the traffic to the destination STA. Traffic between STAs within the BSS may be viewed and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be transmitted between a source STA and a destination STA (e.g., directly between them) in a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (e.g., all of the STAs) may communicate directly with each other. The IBSS mode of communication may be referred to herein as an "ad hoc" communication mode.

[0044] When using the 802.11ac infrastructure mode of operation or a similar mode of operation, an AP may transmit beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width that is dynamically set via signaling. The primary channel may be the operating channel of the BSS and may be used by STAs to establish a connection with the AP. In certain representative embodiments, for example, in an 802.11 system, Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) with collision avoidance may be implemented. With CSMA / CA, STAs (e.g., all STAs), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0045] High Throughput (HT) STAs may use 40 MHz wide channels for communication, which may be formed, for example, through a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels.

[0046] A Very High Throughput (VHT) STA may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz and / or 80 MHz wide channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining eight contiguous 20 MHz channels or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, after channel encoding, the data may pass through a segment parser that may split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing 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 the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration may be reversed, and the combined data may be transmitted to the Medium Access Control (MAC).

[0047] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidths and carriers 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 bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah may support meter-type control / machine-type communications, such as MTC devices within macro coverage areas. MTC devices may have specific capabilities, including, for example, support for (e.g., only for) specific and / or limited bandwidths. MTC devices may include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0048] 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 a primary channel. The primary channel can have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be configured and / or limited by the STAs among all STAs operating in the BSS that support the minimum bandwidth operating mode. In an 802.11ah example, the primary channel can be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only) the 1 MHz mode, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) configuration can depend on the condition of the primary channel. For example, if the primary channel is busy due to STAs (that only support 1 MHz operating mode) transmitting to the AP, the entire available frequency band may be considered busy, even though most of the frequency band may remain idle and be available for use.

[0049] In the United States, the available frequency band that can be used by 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz depending on the country code.

[0050] 1D is a system diagram illustrating the RAN 113 and the CN 115 according to one embodiment. As mentioned above, the RAN 113 may communicate with the WTRUs 102a, 102b, 102c over the air interface 116 using NR radio technology. The RAN 113 may also communicate with the CN 115.

[0051] The RAN 113 may include gNBs 180a, 180b, and 180c, although it will be understood that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, and 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to transmit and / or receive signals to the gNBs 180a, 180b, and 180c. Thus, the gNB 180a may, for example, transmit wireless signals to and / or receive wireless signals from the WTRU 102a using multiple antennas. In one embodiment, the gNBs 180a, 180b, and 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, and the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, and 180c may implement Coordinated Multi-Point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or 180c).

[0052] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of different or scalable lengths (e.g., including different numbers of OFDM symbols and / or lasting different lengths of absolute time).

[0053] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without accessing another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c may utilize one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate with and connect to gNBs 180a, 180b, 180c while also communicating with and connecting to another RAN, such as eNodeBs 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeBs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, while the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0054] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data to User Plane Functions (UPFs) 184a, 184b, routing of control plane information to Access and Mobility Management Functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D , the gNBs 180a, 180b, 180c may communicate with each other via an Xn interface.

[0055] 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements is shown as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0056] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may function as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. Network slicing may be used by the AMF 182a, 182b to customize the CN support of the WTRUs 102a, 102b, 102c based on the type of service utilizing the WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0057] The SMFs 183a and 183b may be connected to the AMFs 182a and 182b in the CN 115 via an N11 interface. The SMFs 183a and 183b may also be connected to the UPFs 184a and 184b in the CN 115 via an N4 interface. The SMFs 183a and 183b may select and control the UPFs 184a and 184b and configure the routing of traffic through the UPFs 184a and 184b. The SMFs 183a and 183b may perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0058] The UPFs 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks such as the Internet 110 to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0059] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0060] 1A-1D and the corresponding descriptions thereof, one or more or all of the functions described herein with respect to one or more of the WTRUs 102a-d, base stations 114a-b, eNodeBs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or any other devices described herein may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation devices may be used to test other devices and / or simulate network and / or WTRU functions.

[0061] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or an operator network environment. For example, one or more emulation devices may perform one or more or all functions while fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in the communication network. One or more emulation devices may perform one or more or all functions while temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation devices may be directly coupled to another device for testing purposes and / or may perform testing using terrestrial wireless communication.

[0062] One or more emulation devices may perform one or more functions, inclusive, while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in test scenarios in a test lab and / or in an undeployed (e.g., test) wired and / or wireless communication network to implement 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 (which may include, e.g., one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0063] The presence of non-line of sight (NLOS) paths in multipath (e.g., reception of signals via multiple paths) may prevent the network from obtaining an accurate location of the WTRU, for example, due to multiple versions of the received positioning reference signal (PRS) that may arrive from different angles and / or at different time units (e.g., absolute time, symbol number, slot number, frame / subframe number, time offset relative to a reference time, etc.). Accurate information about line of sight (LOS), NLOS, and / or other channel characteristics may support accurate positioning (e.g., positioning correction) decisions by the WTRU, a server, etc. Beam refinement (e.g., in the WTRU or network) based on the accurate information may generate assistance information to correct positioning results for improved positioning accuracy in the presence of multipath (e.g., at low latency). Beam refinement may be driven by reports sent from the WTRU or actions taken by the WTRU. For example, LOS identification using uplink (UL) or downlink (DL) multi-beams may be supported for accurate positioning.

[0064] Behavior of a WTRU during a gNB (e.g., network, base station, etc.) scan of channels may be provided. The WTRU may be configured (e.g., by higher layers, e.g., higher layer signaling) to report LOS. The WTRU may report (e.g., to a server) timing information of a configured downlink reference signal (DL RS) for positioning, which may correspond to, for example, the highest reference signal received power (RSRP) among multiple configured reference beams. The network may perform beam sweeping to find LOS and / or NLOS. The action may correspond to, for example, reporting LOS only if multiple beams are configured. In an example, the WTRU may be configured by the network (e.g., LMF or gNB) to report an LOS indicator associated with one or more of a configured PRS resource, a TRP ID, or a cell ID. A value of 1 for the LOS indicator associated with a PRS resource may indicate that the PRS on the PRS resource is likely to be received by the WTRU in the LOS path. If the value of the LOS indicator associated with a PRS resource is 0.8, it may indicate that the PRS on the PRS resource is likely to be received by the WTRU in the LOS path, but less likely than, for example, if the LOS indicator is 1. If the value of the LOS indicator associated with a PRS resource is 0, it may indicate that the PRS on the PRS resource is unlikely to be received by the WTRU in the LOS path. If the value of the NLOS indicator associated with a PRS resource is 1, it may indicate that the PRS on the PRS resource is unlikely to be received by the WTRU in the NLOS path. In an example, it may be assumed that the WTRU is configured to report the LOS indicator associated with the PRS resource to the network.The LOS indicator may be a value determined by the WTRU from a set of discrete values ​​(e.g., [0,0.5,1], [0,0.33,0.66,1], [0,1], or [0.25,0.5,0.75,1]). The LOS indicator may include a set of bits, and a set (e.g., each set) may correspond to one of the discrete values ​​(e.g., “00” for LOS indicator 0, “01” for LOS indicator 0.33, “10” for LOS indicator 0.66, and / or “11” for LOS indicator 1).

[0065] The WTRU may determine an LOS indicator based on measurements made from the PRS on the PRS resource (e.g., arrival time, arrival angle, RSRP, RSTD, and / or WTRU Rx-Tx) and report the indicator to the network. The WTRU may determine not to report an indicator, for example, if the WTRU is unable to determine the likelihood of a path as LOS (e.g., the LOS indicator is 0.5 or the WTRU is unable to determine or calculate an indicator based on measurements made for the received PRS on the PRS resource). In an example, the WTRU may determine to report an error value of the LOS indicator if the WTRU is unable to determine the value of the indicator. For example, if a preconfigured set of discrete values ​​for the LOS indicator is [0,1], the WTRU may not return an LOS indicator associated with the PRS resource to indicate to the network that the WTRU is unsure about the likelihood of LOS associated with the received PRS on the PRS resource. If the pre-configured set of discrete values ​​for the LOS indicator is [0, 0.5, 1] ​​and the associated set of bits for each discrete value is such that “00”, “01”, “10”, and “11” are associated with LOS indicators 0, 0.5, 1, and “error event or unavailable”, respectively, the WTRU may determine to report “11” to the network if the WTRU is unable to determine the discrete value of the LOS indicator based on measurements made on a received PRS on a PRS resource.

[0066] The WTRU may recommend an association between paths in a multipath channel (e.g., a received path, a radio signal reaching the WTRU by more than one path, an LOS or NLOS path, etc.) and beam information. In the case of multipath, the channel referred to herein may refer to the multipath channel. The WTRU may send a measurement report to the network. The report may include, for example, an association of a path ID (e.g., additional path IDs for additional detected paths) in the measured multipath with a channel state information reference signal (CSI-RS), PRS, and / or sounding reference signal (SRS) beam (e.g., an SRS resource ID or SRS beam ID). The associated reference signal (RS) beam may be different from the RS beam received by the WTRU that led to the discovery of the multipath. WTRU-based recommendation of multipath mitigation may consider different beam widths and / or different granularity of transmission period / offset for UL and DL RS. The network may use a broad beam to scan the channel. The WTRU may transmit the information. The WTRU may construct a report based on, for example, the spatial direction of the NLOS / LOS paths and / or the relative delay of the LOS / NLOS paths.

[0067] The WTRU may modify or stop reporting. The WTRU may measure multiple paths. The WTRU may stop measuring at least one of the configured PRS beams that may be associated with the PRS resource, for example, if the measured RSRP corresponding to the PRS beam falls below a threshold and / or the RSRP variance is above a threshold. A variance measurement period (e.g., a period that may be tracked by a timer) may be configured to collect a certain amount of information (e.g., sufficient information). Advice (e.g., implicit advice) may be provided to the network, for example, to discard measurements and / or reduce the size of the measurement report, which may result in a faster decision-making process.

[0068] There may be coordination between DL positioning and UL positioning. The characteristics of DL and UL positioning are illustrated by the example of FIG. 3. The WTRU may transmit multiple configured SRS beams for positioning. The WTRU may expect and / or receive (e.g., may be configured to) dynamically configure the SRS spatial relationship for the positioning SRS (SRSp) and PRS, and / or an indication of in which direction the transmitted SRS was used (e.g., DL-UL coordination, no reporting, and / or beam sweeping).

[0069] The standalone assistance information for positioning corrections may be generated, for example, in a function that may be outside the Location Management Function (LMF). The assistance information (e.g., additional assistance information) for positioning corrections may include, for example, information described herein and / or other information related to the channel, such as LOS / NLOS indications and / or measurement reports. The assistance information may be used, for example, to correct positioning results from a positioning method (e.g., that may be identified and / or defined herein). The assistance information may be distributed (e.g., distributed separately). Generation of the standalone assistance information may be independent of positioning (e.g., LOS / NLOS detection). The assistance information may be generated in a function outside the LMF (e.g., in the RAN or within the WTRU for short latency). The WTRU may obtain the standalone assistance information, for example, on an on-demand basis, and / or the WTRU may be configured (e.g., by a server) to receive the standalone assistance information. The standalone assistance information for the corrections may be distributed to the function by the WTRU, or may be distributed from the function to the WTRU for WTRU-based positioning. In an example, the standalone assistance information may include, for example, multipath channel parameters (eg, relative power offsets, delay profiles, etc.).

[0070] The positioning methods may include, for example, downlink, uplink, and downlink and uplink positioning methods. One or more transmission-reception points (TRPs) (e.g., multiple TRPs) may transmit one or more PRSs (e.g., multiple PRSs) to the WTRU, for example, in a downlink positioning method. The WTRU may observe multiple reference signals. The WTRU may measure the time difference of arrival between pairs of PRSs. The WTRU may report the measured reference signal time difference (RSTD) to the network (e.g., an LMF, which may be used as an example herein). The WTRU may return a measured reference signal received power (RSRP) for the PRSs (e.g., each PRS). The LMF may, for example, determine (e.g., perform) positioning of the WTRU based on the returned measurements. The WTRU may report the RSRP for one or more DL angle-based positioning methods.

[0071] The WTRU may transmit a positioning SRS to one or more reception points (RPs), for example, in an uplink positioning method. The SRS may be configured by radio resource control (RRC). The TRP may measure the relative time of arrival (RTOA) for the received SRS, for example, in the case of a timing-based method. The TRP may report the measurement to the LMF. The WTRU may report the RSRP for the SRS. The RP may measure the angle of arrival (AoA), for example, in the case of an angle-based uplink positioning method, and report the measured AoA to the LMF.

[0072] The WTRU may measure the receiver-transmitter (Rx-Tx) time difference between the received PRS and the transmitted SRS, for example, in uplink and downlink positioning methods. The WTRU may report the Rx-Tx time difference to the LMF. The WTRU may report the measured RSRP for the PRS. The TRP may calculate the Rx-Tx difference between the received SRS and the transmitted PRS.

[0073] Timing information may be a component in positioning. Timing issues (e.g., and positioning issues) may arise. For example, a DL and / or uplink UL reference signal (RS) for positioning that passes through multipath may generate multiple copies at the receiver side, which may, for example, create multiple timing and / or angle measurements at the receiver. The multipath may be a combination of LOS and NLOS paths. Identifying LOS and NLOS paths in the multipath may be useful, for example, to determine accurate timing and positioning.

[0074] FIG. 2 illustrates an example of multipath during positioning.

[0075] The WTRU may report information related to paths (eg, additional paths) that the WTRU may observe, for example, when the WTRU receives a PRS from a TRP.

[0076] Positioning accuracy may be degraded without a mechanism for identifying paths (e.g., as LOS or NLOS). The WTRU may measure multipath information. Positioning accuracy may be supported, for example, by allowing / enabling the WTRU to associate path information with DL RS and / or UL RS.

[0077] For example, multiple beams and reporting configurations may be provided (e.g., and / or utilized) for positioning. "Positioning SRS" may refer to an SRS signal / transmission used for positioning. Resources for positioning SRS may be defined / configured (e.g., signaled) by, for example, RRC. A "positioning SRS" or "SRS" may include, for example, at least one of an SRS configured under SRS-PosResourceSet-r16 and SRS-PosResource-r16, an SRS configured under SRS-ResourceSet and SRS-Resource, an SRS not configured under SRS-PosResourceSet-r16 and SRS-PosResource-r16, an SRS not configured under SRS-ResourceSet and SRS-Resource, an SRS not associated with SRS-PosResourceSet-r16, SRS-PosResource-r16, SRS-ResourceSet, or SRS-Resource, an uplink reference signal associated with positioning, a demodulation reference signal (DM-RS) for the uplink, or a phase tracking reference signal (PTRS) for the uplink.

[0078] The positioning SRS may be denoted as "SRSp." The PRS and SRS may not be limited to RSs used for positioning. The examples described herein may apply to or be used with DL reference signals (e.g., any DL reference signal) and UL reference signals (e.g., any UL reference signal).

[0079] The examples described herein may be applicable to one or more of the following positioning methods: “DL positioning method,” “UL positioning method,” or “DL and UL positioning method.” The methods may be implemented in a device, such as a WTRU, a network-side device, etc.

[0080] A "DL positioning method" may refer to a positioning method that utilizes a downlink reference signal (e.g., PRS). The WTRU may receive multiple reference signals from the TP. The WTRU may measure DL RSTD and / or RSRP. DL positioning methods may include, for example, downlink angle of departure (DL-AoD) positioning, downlink time difference of arrival (DL-TDOA) positioning, etc.

[0081] A "UL positioning method" may refer to a positioning method that utilizes an uplink reference signal (e.g., SRS) for positioning or SRS measurement. The WTRU may transmit the SRS to multiple RPs (e.g., network devices that receive the SRS from the WTRU). The RPs may measure the UL RTOA and / or RSRP. UL positioning methods may include, for example, UL-TDOA positioning, UL-AoA positioning, etc.

[0082] RP, TP, and TRP may refer to network devices. In examples, RP, TP, and TRP may refer to whether a "point" transmits (e.g., only transmits) (e.g., it may be referred to as a TP), receives (e.g., only receives) (e.g., it may be referred to as an RP), or transmits and receives (e.g., both transmits and receives) (e.g., it may be referred to as a TRP). For UL positioning methods (e.g., UL TDOA or UL-AoA), the network side device may be referred to as the RP (e.g., the network only receives the SRS from the WTRU). For DL ​​positioning methods, the network device may be referred to as a TRP or TP (e.g., the network either only transmits the PRS or transmits the PRS and receives measurements). For DL ​​and UL positioning methods (e.g., multi-RTT), the network device may be referred to as a TRP (e.g., the network transmits the PRS and receives the SRS).

[0083] A "DL and UL positioning method" may refer to a positioning method that utilizes uplink and downlink reference signals for positioning. In an example, a WTRU may transmit an SRS to multiple TRPs, and the network (e.g., a base station or gNB) may measure the Rx-Tx time difference. The network may measure the RSRP for the received SRS. The WTRU may measure the Rx-Tx time difference for PRSs transmitted from multiple TRPs. The WTRU may measure the RSRP for the received PRS. The measured Rx-Tx difference and / or RSRP at the WTRU and / or the network may be used to calculate the round trip time (RTT). The WTRU Rx and Tx difference may refer to the difference between the arrival time of a reference signal transmitted by a TRP and the transmission time of a reference signal transmitted from / by the WTRU. The network (e.g., gNB) Rx and Tx difference may refer to the difference between the arrival time of a reference signal transmitted by the WTRU and the transmission time of a reference signal transmitted from / by the network (e.g., a gNB or TRP). Multi-RTT positioning may be an example of DL and UL positioning.

[0084] The network may include, for example, one or more of an Access and Mobility Management Function (AMF), an LMF, a next generation RAN (NG-RAN), and the like.

[0085] The LMF may be an example of a node or entity (e.g., a network node or entity) that may be used for or to support positioning. Other types of nodes or entities may be used in place of the LMF and may be applicable with the present disclosure.

[0086] "Location information" and "location estimate" may be used interchangeably herein. "Transmitting PRS resources" and "transmitting a PRS on PRS resources" may be used interchangeably herein. "Receiving PRS resources" and "receiving a PRS on PRS resources" may be used interchangeably herein. "Transmitting SRS resources" and "transmitting an SRS on SRS resources" may be used interchangeably herein. "Receiving SRS resources" and "receiving an SRS on SRS resources" may be used interchangeably herein. "Transmitting SRSp resources" and "transmitting an SRS on SRS resources" may be used interchangeably herein. "Receiving SRS resources" and "receiving an SRS on SRS resources" may be used interchangeably herein.

[0087] Multi-beam-based positioning may be provided (e.g., configured and / or utilized). Multi-beam diversity may be provided for positioning measurements. Positioning measurement reference signals (PMRS) may be transmitted or received in one or more beams. A beam may include (e.g., may be referred to as) quasi-co-location (QCL) Type D, spatial relationship information, beam reference signals, channel state information reference signal (CSI-RS) indices, and / or synchronization signal block (SSB) indices, for example. PMRS may be used interchangeably with PRS, SRSp, global navigation satellite signal (GNSS) signals, positioning beam reference signals, CSI-RS, and / or SSB, for example.

[0088] One or more beams may be used for PMRS transmission. The one or more beams may be transmitted, for example, from a TRP or cell (e.g., the same TRP or cell). The one or more beams may be transmitted, for example, using spatial division multiplexing (SDM), time division multiplexing (TDM), and / or frequency division multiplexing (FDM). A set of beams used for PMRS transmission (e.g., from the same TRP or cell) may be referred to as a positioning beam group (PBG).

[0089] The WTRU may be configured with a PBG for positioning measurement reporting. The WTRU may perform positioning measurements from the PBG, for example, based on at least one of the following:

[0090] The WTRU may report positioning measurements for beams (e.g., all beams) in the PBG that have one or more multipaths (e.g., the first N paths) for a beam (e.g., each beam) in the PBG. The value of N may be determined, for example, based on the number of beams in the PBG. The value of N may be equal to 3, for example, if the number of beams (e.g., M) in the PBG is less than a threshold (e.g., M<2), and N may be equal to 1, for example, if not (e.g., M≧2). The value of N may be configured or determined per beam (e.g., beam index).

[0091] The WTRU may report positioning measurements for a subset of beams in a PBG that have one or more multipaths for the subset of beams (e.g., the first N paths). The subset of beams may be determined based on, for example, at least one of: a beam with an LoS path, a beam with the strongest RSRP for the first path, a beam with the fewest number of paths, or a beam with the highest measurement accuracy and / or quality. The subset of beams may include one or more beams (e.g., a single beam or multiple beams).

[0092] The WTRU may, for example, report positioning measurements of one or more beams if the one or more beams meet (e.g., satisfy) one or more conditions (e.g., predefined conditions). The conditions may include, for example, at least one of whether an LoS path exists for the beam, whether the positioning measurement quality (e.g., RSRP or Level 1 (L1)-RSRP) is higher than a threshold, or whether the number of paths in the multipath channel is less than a threshold.

[0093] One or more of the operation modes may be used (e.g., single beam mode or multi-beam mode). The first operation mode may be single beam operation for positioning (SBP), and the second operation mode may be multi-beam operation for positioning (MBP). For example, SBP may be based on a PBG having a single beam. A PBG including a single beam for positioning measurements may be referred to as an SBP. For example, MBP may be based on a PBG having two or more beams. A PBG including two or more beams for positioning measurements may be referred to as an MBP.

[0094] The WTRU may determine the operating mode (eg, SBP or MBP) for the positioning measurements based on, for example, one or more of the following:

[0095] The operating mode may be configured, for example, for one or more sources (e.g., all sources or each source). A source may be, for example, a TRP, a cell, etc.

[0096] The operating mode may be indicated, for example, based on aperiodic positioning measurements (e.g., the mode may be indicated if an aperiodic positioning measurement report is triggered). For example, triggering downlink control information (DCI) may indicate the operating mode. The operating mode may be determined (e.g., implicitly determined) based on the number of beams in the PBG, which may be indicated, for example, in the triggering DCI.

[0097] The operating mode may be determined based on, for example, channel conditions. For example, a WTRU may be configured with an SBP and an MBP. The WTRU (e.g., configured with an SBP and an MBP) may determine, for example, a first operating mode (e.g., MBP) if one or more of the conditions are met (e.g., satisfied), and may otherwise determine, for example, a second operating mode (e.g., SBP). The WTRU may determine, for example, the first operating mode (e.g., MBP) if one or more of the following conditions are met (e.g., and the WTRU may determine the second operating mode, such as SBP, if the following conditions are not met): the measurement quality (e.g., and / or beam quality) of one or more beams (e.g., all beams and / or the strongest beam) at the MBP is lower than a threshold, the RSRP gap between the strongest beam and the second strongest beam is greater than a threshold at the PBG, an LoS path exists for positioning measurements at the SBP, or the measurement quality (e.g., and / or beam quality) of the beam at the SBP is higher than a threshold.

[0098] The operating mode may be indicated, for example, in a DCI that triggers aperiodic positioning measurement reporting.

[0099] Features related to reporting behavior may also be provided. Reporting may stop, for example, if the RSRP or RSRP variance of the measurements falls below a threshold. The WTRU may perform periodic reporting of positioning measurements. The WTRU may be configured with one or more sets (e.g., multiple sets) of reporting resources to perform positioning measurement reporting. The set (e.g., each set) of reporting resources may include, for example, at least one of the time and frequency of resources for reporting, a time offset of the resources, or a periodicity of the resources.

[0100] A WTRU may be configured with which beam and / or which path of a beam (e.g., each beam) to report (e.g., for each set of reporting resources). In an example, a WTRU may be configured with multiple sets (e.g., two) of reporting resources. The WTRU may be configured with a first set of reporting resources that may be used to report the first path and / or strongest path of a beam (e.g., all beams). The WTRU may be configured with a second set of reporting resources that may be used to report the second path and / or second strongest path of a beam (e.g., all beams). The first set of reporting resources may have a shorter periodicity than the second set of reporting resources; for example, this may enable / allow the WTRU to report the second path and / or second strongest path of each beam less frequently (e.g., occasionally) (e.g., compared to more frequent reporting of the first path and / or strongest path). In an example, a WTRU may be configured with multiple sets of reporting resources, and a set of reporting resources (eg, each set) may be associated with measurements on a beam (eg, one beam).

[0101] The WTRU may, for example, determine which beam / path to report when performing a positioning measurement report. The WTRU may determine which beam / path to report on in a positioning measurement report. The WTRU may, for example, be configured with one or more of the following parameters (e.g., to determine whether to report a beam, path, and / or RSTD for a positioning measurement): minimum RSRP and / or received signal strength indicator (RSSI) of a beam, minimum RTT gap between the considered beam and minimum RTT, minimum RSRP / RSSI of the path to report, minimum and / or maximum time gap (e.g., delay spread) between two paths, minimum and / or maximum RSTD difference between the considered beam and minimum RSTD of one or more other TRP pairs, or minimum dispersion of RSRP of a beam.

[0102] The WTRU may determine whether to report a beam, path, and / or RSTD for positioning measurements based on, for example, the minimum RSRP / RSSI of the beam. The WTRU may report positioning measurements for a beam if, for example, the RSRP / RSSI of the beam is greater than a configured minimum.

[0103] The WTRU may determine whether to report a beam, path, and / or RSTD for positioning measurements based on, for example, a minimum RTT gap between the considered beam and the minimum RTT. For example, the WTRU may be configured to report positioning measurements for multiple beams (e.g., two beams). The WTRU may not report (e.g., may be configured not to report) positioning measurements for one of the beams if, for example, the time gap difference between the multiple RTTs (e.g., two RTTs) is greater than a configured value.

[0104] The WTRU may determine whether to report a beam, path, and / or RSTD for positioning measurements based on, for example, the minimum RSRP / RSSI of the path to be reported. The WTRU may report positioning measurements for a path if, for example, the RSRP / RSSI of the path is greater than a configured minimum value.

[0105] The WTRU may determine whether to report a beam, path, and / or RSTD for positioning measurements based on, for example, the minimum and / or maximum time gap (eg, delay spread) between two paths.

[0106] The WTRU may determine whether to report a beam, path, and / or RSTD for positioning measurements based, for example, on the minimum and / or maximum RSTD difference between the considered beam and the minimum RSTD of one or more TRP pairs (e.g., other TRP pairs).

[0107] The WTRU may determine whether to report a beam, path, and / or RSTD for positioning measurements based on, for example, the minimum variance of the RSRP of the beam. The presence of LOS may be indicated, for example, by a low variance of RSRP. The presence of NLOS may be indicated, for example, by a high variance of RSRP. The WTRU may determine, for example, not to perform measurements on paths that exhibit an RSRP variance below a threshold.

[0108] The WTRU may determine whether to report positioning measurements for a beam / path based on, for example, a change compared to a report (e.g., a previous report). The WTRU may determine whether to report positioning measurements for a beam / path (e.g., one beam / path) based on, for example, the variance of the positioning measurements compared to a previously reported positioning measurement (e.g., the last reported positioning measurement). The WTRU may not perform positioning measurement reporting for one or more of the beams / paths, RSTD, etc., if, for example, the variance of the measurements compared to the previously reported measurement is less than (e.g., below) a threshold. In an example, the WTRU may be configured with, for example, an RSRP variance threshold to determine whether to perform reporting for a beam. The WTRU may report positioning measurements for a beam if, for example, the RSRP difference between the current measurement and the last reported measurement is greater than a threshold. The WTRU may not perform reporting of positioning measurements for a beam if, for example, the RSRP difference between the current measurement and the last reported measurement is less than or equal to a threshold.

[0109] For example, by applying multi-beam based positioning and / or reporting behavior (e.g., as described herein), the size of reports may be reduced, the frequency of reports may be reduced, and / or the system may achieve accurate positioning with low latency.

[0110] The path information may be associated with the reference signal. For example, the WTRU may identify multipath paths and make a respective association (e.g., connection) between each path and a respective reference ID, e.g., a respective reference ID number. The reference ID may be one or more of the following: a PRS resource ID number, a positioning SRS resource ID number, an SRS resource ID number, a PRS resource set ID number, a positioning SRS resource set ID number, or an SRS resource set ID number.

[0111] The WTRU may detect multiple paths, for example, by receiving multiple copies of the transmitted PRS from the TP (e.g., in the presence of a multipath channel). For the received PRS, different RSRPs, ToAs, and / or RSTDs may be observed. For example, if the WTRU reports timing-related information and the RSRP, the size of the report may increase and / or the quality of the report may degrade. Positioning / location information may be associated with short latency. Reporting may consume time for preparation, which may increase latency (e.g., lead to high latency). Bandwidth-efficient reporting may be achieved without high latency, for example, if the WTRU is capable (e.g., configured) of associating one or more (e.g., pre-configured) beams with the detected paths and reporting the association to the network.

[0112] The WTRU may report associations between detected paths and reference signals to the network, for example, to assist the network in identifying NLOS and LOS paths. In an example, the WTRU may be configured with PRS resources. Resources (e.g., each resource) may be associated with a beam transmitted from the TP. The WTRU may receive a PRS (e.g., a PRS transmission) from the TP and may detect multiple paths. The WTRU may determine whether to assign an identification number to a detected path if at least one of the following criteria is met: the measured RSRP for the detected path exceeds a threshold (e.g., a predefined threshold) or the difference in ToA compared to one or more other detected paths exceeds a threshold (e.g., a predefined threshold).

[0113] The WTRU may assign (e.g., determine to assign) an identification number to the detected path if, for example, the above criteria and / or conditions are not met. The identification number assigned to the detected path may be referred to as a "path ID."

[0114] The WTRU may report the detected paths and / or the respective path IDs associated with each respective detected path to the network, for example, when the WTRU receives a request from the network to send an assignment (e.g., assignment of path identifiers (IDs) to the detected paths). In an example, the WTRU may detect four paths in a multipath channel, and the WTRU may assign path IDs #1, #2, #3, and #4 to each detected path and may report the assignments to the network. In an example, the order of assignments may be based on RSRP (e.g., the path with the highest RSRP may receive ID #1 and the path with the lowest RSRP may receive the last ID number) or based on arrival time (e.g., the first path with the earliest arrival time may receive ID #1 and the path with the latest arrival time may receive the last ID number). The WTRU may assign ID #1 to the LOS path and the remaining ID numbers to the NLOS paths based on criteria using RSRP or arrival time. The WTRU may send the assignment using a protocol (e.g., LTE positioning protocol (LPP) or RRC signaling). The WTRU may send the assignment, for example, by uplink control information (UCI) or a MAC control element (MAC-CE) if configured by the network. The WTRU may send the report, for example, using RRC signaling, MAC-CE, or UCI. The WTRU may include the report in a physical uplink control channel (PUCCH) transmission or a physical uplink shared channel (PUSCH) transmission.

[0115] The WTRU may associate a path (e.g., a first path or a second path, which may include a first path ID or a second path ID, respectively) with one or more configured reference signals (e.g., a first configured reference signal or a second configured reference signal). The reference signal may be associated with an identification number assigned to the detected path. The reference signal may include, for example, at least one of a CSI-RS, a PRS, a DM-RS, a tracking reference signal (TRS), a DL PTRS, an UL PTRS, an SRSp, or an SRS.

[0116] The WTRU may associate a path ID with a reference signal, for example, by using a resource ID or other ID (e.g., a unique ID), such as an ID that may be used to generate the reference signal. The WTRU may associate the path ID with a resource set ID, for example, if available, that may be assigned to the reference signal.

[0117] In an example, e.g., referring to the example described with respect to FIG. 2, a WTRU may report to a network (e.g., a network entity such as an LMF or gNB) that, for example, a path (e.g., ID#1) corresponding to the NLOS path of FIG. 2 is associated with SRS resource #2 belonging to SRS resource set #1. As described herein, different resource numbers may correspond to transmit beams directed in different directions. The WTRU may inform the network about the direction corresponding to where the path was detected, e.g., by associating a path ID with a resource ID. The network may have knowledge of the direction from which the PRS was transmitted and the direction of the SRS transmit beam corresponding to SRS resource #2. The association of a resource with a path ID may assist the network in the direction from which the WTRU may have received the PRS, which may support (e.g., lead to) identification of the NLOS path.

[0118] The WTRU may report the association between the path ID and the RS to the network, for example, if requested by the network. The WTRU may include (e.g., in the report) timing-related information, RSRP, and / or association information, for example. The WTRU may send the report using, for example, RRC, MAC-CE, or UCI. The WTRU may include the report in, for example, a PDCCH or PDSCH transmission.

[0119] The WTRU may receive spatial information from the network (e.g., from the LMF or gNB) associating DL RSs, UL RSs, and / or path IDs transmitted from the TRP. For example, the WTRU may receive PRS resource #1 associated with a path (e.g., path ID #0) and SRS resource ID #2 (e.g., based on spatial information such as path direction and spatial relationship). The WTRU may receive spatial information from the network associating multiple DL RSs with the same path ID; e.g., the spatial information may indicate that multiple DL RSs may be transmitted from the TRP and may reach the WTRU along the same path indicated by the path ID. The WTRU may receive information (e.g., configuration information) associating multiple UL reference signals with the same path ID; e.g., the information may indicate that multiple UL reference signals may reach the TRP along the same path indicated by the path ID.

[0120] In an example, LOS and NLOS path detection may be implemented (eg, as described herein) without large bandwidths for transmitting measurement reports (eg, detailed measurement reports).

[0121] There may be coordination between the downlink and uplink. In an example DL and UL positioning method, a TRP (e.g., each TRP) may transmit a PRS to a WTRU, and the WTRU may transmit an SRSp (e.g., in reply) to the TRP (e.g., each TRP). The Rx-Tx time difference may be calculated in the TRP (e.g., each TRP) and the WTRU. The WTRU may receive the transmitted PRS from the TRP. The WTRU may receive multiple copies of the PRS, for example, due to the presence of multipath. A bandwidth-efficient reporting method may assist the network in detecting LOS and / or NLOS paths.

[0122] The WTRU can determine the direction of the LOS and / or NLOS paths from the dynamic association between the DL and UL reference signals generated by the network.

[0123] The WTRU may, for example, use the SRSp to perform beam sweeping. The beam sweeping may be configured, for example, by setting the periodicity of the SRSp transmission. The WTRU may, for example, transmit a different beam at each transmission opportunity (e.g., switch beams at each transmission opportunity). The WTRU may repeat transmission of a beam (e.g., the same beam at a predefined number of repetitions) during the periodic transmission of the SRSp.

[0124] A beam (e.g., each beam) transmitted from the WTRU may be assigned a corresponding SRSp resource identification number. The SRSp can be used to perform beam sweeping. The WTRU may receive an association report from the network, for example, the association report may associate an SRSp (e.g., each SRSp) with a DL reference signal by an identification number. The identification number (e.g., resource ID or resource set ID) may be aligned with the Rx beam used by the TRP to receive the transmitted SRSp. The association report may be a reconstruction of the spatial relationship between the SRSp and the DL reference signal. The network may associate a received SRSp with another SRSp by a different identification number, which may occur, for example, if the received SRSp passes through a line-of-sight path. Different SRSp beams may have passed through the same line-of-sight path.

[0125] The WTRU may receive an association between the SRSp and a DL or UL reference signal, e.g., via DCI, MAC-CE, or RRC. For example, the WTRU may determine a change in spatial relationship information for the SRSp via the DCI. The DL reference signal may include, e.g., one or more of the CSI-RS, DMRS, PRS, TRS, or PTRS. The WTRU may receive a configuration associating the transmitted SRSp with an SSB.

[0126] The WTRU may use a beam associated with a DL RS, for example, if the WTRU receives an update to the spatial relationship information. The WTRU may perform another beam sweep focusing, for example, to a beam that may be in the same direction as the beam associated with the DL RS in the updated spatial information, for example, if the WTRU receives an update to the spatial relationship information. In an example, the WTRU may receive spatial information associating SRSp resources #1-#4 with PRS resource #1. In the updated spatial information, the WTRU may receive spatial information associating SRSp resources #3-#6 with PRS resource #1. In this case, based on the updated spatial information, the WTRU may perform beam sweeping using SRSp resources #3-#6 that are related to PRS resource #1.

[0127] LOS and NLOS path detection can be implemented (e.g., as described herein) without large bandwidths for transmitting measurement reports (e.g., detailed measurement reports), thereby enabling the system to perform positioning (e.g., accurate positioning).

[0128] A WTRU may determine and / or report its orientation. The WTRU may report information related to its orientation angle to the network. The network may configure PRS transmission parameters in the presence of multipath, for example, based on the orientation angle of the WTRU. For example, the likelihood that LOS may exist may depend on the orientation of the WTRU, and that information may be used by the network to configure the PRS (e.g., so that positioning accuracy may be improved). "WTRU orientation," "WTRU orientation angle," "orientation angle," and "orientation information" may be used interchangeably herein.

[0129] The WTRU may, for example, explicitly report its absolute or relative orientation. The WTRU may report its orientation to the network, for example, to assist the network in reconfiguring network and / or WTRU parameters. The WTRU may indicate (e.g., explicitly indicate) its orientation information to the network, for example, in a measurement report. In an example, the orientation of the WTRU may be defined as the direction in which a reference point of the WTRU is pointing. The reference point may be implementation dependent. For example, the reference point may be the screen of a smartphone. Information related to the orientation angle of the WTRU may include at least one of an azimuth angle (the angle may be measured counterclockwise from geographic north and / or counterclockwise from the x-axis of a local coordinate system (LCS)), an elevation angle, which may be measured relative to the zenith and pointing toward the horizon, or an elevation angle, which may be measured relative to the z-axis of the LCS.

[0130] The WTRU may report a rotation angle relative to a reported orientation value (e.g., a previously reported orientation value). For example, the WTRU may report an angle measured counterclockwise from the previously reported orientation of the WTRU. The occasion for reporting the WTRU's rotation angle may include a measurement reporting occasion. For example, the WTRU may report the rotation angle relative to the WTRU's orientation at the last measurement reporting occasion.

[0131] The WTRU may be (pre)configured to report its orientation angle based on the RSRP of the PRS received from the TRP falling below a preconfigured threshold and / or based on the RSRP of the PRS received from the TRP remaining below a preconfigured threshold, for example, for a preconfigured duration.

[0132] The WTRU may include information related to its orientation in a request for configuration or reconfiguration of PRS-related parameters (e.g., in the LPP request assistance data). The request for configuration or reconfiguration of PRS-related parameters may include one or more of the number of symbols for the PRS, the transmit power of the PRS, the number of PRS resources included in the PRS resource set, the muting pattern of the PRS (e.g., the muting pattern may be represented by a bitmap), the periodicity of the PRS, the type of PRS or SRS (e.g., periodic, semi-persistent, or aperiodic), the slot offset of the periodic transmission of the PRS, the vertical shift of the PRS in the frequency domain, the time gap during repetition of the PRS, the repetition factor of the PRS, the RE offset of the PRS, the combination pattern of the PRS, the spatial relationship, the sequence ID used to generate the PRS or PRS ID, the TRP ID, etc.

[0133] The WTRU orientation information may be sent, for example, to the LMF or RAN via an LPP message or an RRC message. The WTRU may send information related to the orientation of the WTRU, for example, when the WTRU sends capability information about the WTRU to the network. The request for reconfiguration may include at least one of a request to transmit a PRS from a different TRP, or a request for a new PRS resource, PRS resource ID, or PRS resource set.

[0134] The WTRU may report its orientation information, for example, implicitly. The WTRU may transmit information that can be used to infer the WTRU's orientation. For example, the WTRU may report the panel ID, receive beam group index, or receive beam set index to which the DL-PRS receive beam index belongs (e.g., along with the DL-PRS receive beam index). The WTRU may report the panel ID from which the positioning SRS may be transmitted. The panel ID may correspond to the panel used to receive the DL-PRS and / or transmit the positioning SRS. The WTRU may report a panel ID that is different from the panel ID configured by the RAN or LMF to transmit the positioning SRS (e.g., the WTRU may implicitly report its orientation using features described herein).

[0135] The WTRU may have an Rx antenna gain for the panel (e.g., different Rx antenna gains for each panel). The WTRU may transmit (e.g., indicate) the gain characteristics of the Rx beam or Rx panel, for example, as part of the WTRU capability information. The capability information may assist the network in inferring the orientation of the WTRU, for example, based on the reported RSRP characteristics. The gain characteristics of the Rx beam may be represented by the relative difference in gain between the Rx beams. The panel information associated with the different gains may assist the network in calculating the orientation angle of the WTRU.

[0136] The information described herein may be used by the network to determine the orientation of the WTRU, for example, if knowledge of the location of the associated panel is available to the network.

[0137] The WTRU may request a reconfiguration of PRS-related parameters, for example, if one or more characteristics of the Rx beam change beyond a preconfigured threshold. The change may include, for example, a change in the Rx beam index over a preconfigured duration and / or a change in the Rx panel or resource set index over a preconfigured duration.

[0138] The index associated with the highest RSRP measurement may be indicated. The index reported by the WTRU may be (pre-)configured. For example, the WTRU may indicate to the network, for example, the beam index, panel index, beam group index, and / or beam set index at which the highest RSRP was measured for a PRS resource (e.g., a given PRS resource) within a resource set. The measured RSRP may be the highest among the RSRPs measured using one or more Rx beam indices (e.g., all Rx beam indices) for the PRS resource (e.g., a given PRS resource), or the WTRU may report the highest RSRP along with a group or set of one or more PRS beam indices, resource indices, and / or resource set indices. For example, the WTRU may report, for a given PRS resource set, the PRS resource ID that may result in the highest RSRP along with the measured RSRP. The WTRU may report the PRS resource set that may result in the highest RSRP among the configured PRS resource sets. The WTRU may report the Rx beam index, Rx panel ID, and / or PRS resource ID pair that may correspond to the highest RSRP (e.g., for a given PRS resource set). The WTRU may include an indicator in the report to indicate that the reported index or indices correspond to the PRS resource / resource set index, Rx beam index / panel ID, or Rx beam index and / or PRS resource ID pair that may result in the highest RSRP.

[0139] The indication may be included in an LPP message, an RRC message, a DCI, or a MAC-CE. The index from which the highest RSRP is obtained may be used to infer the direction the WTRU may be facing (e.g., this may assist the network in determining the orientation angle of the WTRU). The WTRU may include an indication (e.g., in the same message) that the measured RSRP is highest.

[0140] The WTRU may, for example, report or include in its report an indication of the PRS resource ID on which the highest RSRP is measured among one or more PRS resources (e.g., all PRS resources) that the WTRU is configured to measure. The indication may assist the network in determining the orientation angle of the WTRU.

[0141] The WTRU may do one or more of the following to request a reconfiguration of PRS-related parameters: The WTRU may detect a decrease in the RSRP of the measured PRS. The WTRU may perform an RX beam sweep and / or turn on an RX panel facing a different direction. On the condition that the RSRP does not improve after the RX beam sweep, the WTRU may decide to request a reconfiguration of PRS-related parameters. The WTRU may send a request for a reconfiguration of PRS parameters. The request for a reconfiguration may include one or more of the following (e.g., to assist the LMF in selecting optimal parameters): The request may include a desired angle relative to a predefined direction (e.g., geographic north), and the WTRU may receive the PRS from different TRPs. The request may include the measured RSRP for one or more Rx panels, beam sets, and / or beam indices (e.g., all Rx panels, beam sets, and / or beam indices). The request may include the Rx beam set / group, panel ID, and / or beam index where the maximum RSRP is observed (e.g., this information may be useful for the network to determine the orientation angle of the WTRU). The request may include the AoA along with the RSRP.

[0142] Corrective information may be provided / supported. Reports (e.g., additional reports) may be provided for low latency.

[0143] The WTRU may send a measurement report to the network, including, for example, RSRP and / or timing-related information that may pertain to a path (e.g., an additional path). The network may process the measurement report. The network may inform the WTRU about the results of the LOS and / or NLOS path classification. The network may perform positioning with low latency, for example, if the measurement report does not spend a significant amount of time reaching a network component (e.g., an LMF). Low-latency positioning may be achieved, for example, if the WTRU performs the LOS and NLOS path classification. The classification may utilize processing (e.g., additional processing) that may consume battery power in the WTRU. In an example, the WTRU may not have the capability to perform calculations for LOS and NLOS path classification.

[0144] The WTRU may send network measurement reports (e.g., additional measurement reports) for LOS or NLOS classification (e.g., which may be separate from the measurement reports) and may be as described herein. For example, the WTRU may send additional information that may include RSRP and / or timing-related information related to detected additional paths to the network (e.g., gNB).

[0145] 3 illustrates an example of receiving standalone assistance information for a DL positioning method. As shown by the example of FIG. 3, the WTRU may transmit information (e.g., additional information) to the gNB, for example, based on a request for a measurement report (e.g., additional measurement report) received from the gNB. In the example, the one or more triggers for transmitting the additional measurement report to the gNB may be based, for example, on one or more of the following conditions (e.g., detected at the WTRU): detection of one or more changes in the WTRU's environment, interference measurements, or higher layer signaling / application indication.

[0146] The trigger for transmitting additional measurement reports to the gNB can be based, for example, on the detection of one or more changes in the WTRU's environment. The WTRU can transmit additional measurements, for example, if the WTRU detects the presence and / or persistence of an obstruction condition on a measured path. The WTRU can transmit additional information (e.g., related to timing and / or angle) based, for example, on a change (e.g., an expected change) in one or more paths from LOS to NLOS and vice versa.

[0147] The trigger for sending additional measurement reports to the gNB can be based on, for example, interference measurements. The WTRU can transmit additional measurements, for example, when it measures interference on one or more paths, e.g., when the measured interference power exceeds a threshold (e.g., a predefined threshold) on a path.

[0148] The trigger for sending additional measurement reports to the gNB can be based, for example, on higher layer signaling / application indication. For example, the WTRU can indicate information related to the integrity and / or reliability on the path. The integrity and / or reliability values ​​can be determined, for example, as a function of RSRP measurements of one or more paths over a duration (e.g., a configured duration).

[0149] The additional measurement information transmitted by the WTRU may be identified, for example, by an ID that can be correlated with the ID of another measurement report (e.g., original / first measurement report). The measurement report may be transmitted, for example, per path. The identifier used for the path in the additional measurement information may, for example, be an extension of the ID used for the path in another measurement report (e.g., original / first measurement report). For example, when transmitting additional measurement information, the WTRU may transmit timing information (e.g., timestamp) for each path or for each multipath, for example, to indicate the relevance / freshness of the additional measurement information.

[0150] A function within the gNB can use the additional information, for example, to classify paths (e.g., additional paths) into NLOS paths and LOS paths. The WTRU can receive path correction information from the gNB, which may include, for example, one or more of multipath channel related information (e.g., delay spread, average delay, number of taps in the multipath fading channel, relative delay between each tap, and / or relative power offset between each tap), phase offset, timing offset, power offset, or LOS and / or NLOS path classification results.

[0151] The WTRU may use the path correction information to correct the position derived from measurements obtained from the PRS.

[0152] The correction information may be transmitted, for example, periodically. The WTRU may receive (e.g., periodically receive) correction information regarding the timing offset from the network. The correction information regarding the timing offset may be used to compensate for an unknown timing offset in the Tx or Rx transmission or in the receive filter. The network may estimate the timing offset and report (e.g., transmit) it to the WTRU (e.g., via the correction information). The WTRU may apply the timing offset (e.g., provided by the network) to timing-related measurements such as the arrival time or the time difference associated with the arrival. The timing offset may occur (e.g., arise) periodically (e.g., with unexpected offsets in a multipath channel). The correction information regarding the timing offset may be transmitted (e.g., from the network) to the WTRU periodically.

[0153] The correction information described herein may be transmitted to the WTRU via one or more of the following: The correction information may be transmitted via periodic transmission. The WTRU may receive a configuration regarding the periodicity with which the correction information may be transmitted. The correction information may be transmitted via semi-persistent transmission. The WTRU may receive a configuration regarding the periodicity with which the correction information is transmitted. The transmission may end with the MAC-CE or after a duration (e.g., a timer) expires (e.g., the duration and / or timer value may be configured). The correction information may be transmitted via aperiodic transmission. The WTRU may receive the correction information on an on-demand basis. For example, the WTRU may transmit a request for correction information and receive the correction information in response. The WTRU may receive the correction information after receiving an indication from the network that the correction information should be transmitted (e.g., based on a preconfigured timing or transmission schedule).

[0154] The methods described herein may be applicable to DL and DL and UL methods using PRS (eg, as described with respect to FIG. 4).

[0155] 4 illustrates an example for receiving standalone assistance information for DL ​​and UL positioning methods. For example, the WTRU may transmit an SRS to the gNB. The gNB may perform measurements. The standalone assistance information may be generated, for example, based on the SRS measurement results and a channel measurement report (e.g., an additional channel measurement report). The WTRU may, for example, use the standalone assistance information to make corrections to its position. The WTRU may transmit the SRS, for example, based on an additional measurement report request sent from the gNB.

[0156] LOS and NLOS classification can be achieved with low latency (e.g., without WTRU processing), for example, by enabling / utilizing capabilities within the gNB to process additional information.

[0157] The WTRU may have one or more of the following behaviors associated with multiple path detection and / or WTRU-assisted timing-based positioning.

[0158] With regard to multipath detection and related WTRU behavior (e.g., for timing-based positioning methods such as DL-TDOA or multi-RTT), angle information and / or RSPR reporting with finer granularity may not be available at the WTRU or network (e.g., gNB), for example, when there are multiple paths associated with a channel. This may reduce the accuracy of WTRU positioning.

[0159] The WTRU may indicate the presence of a multipath channel to the network (e.g., to the LMF) by reporting RSRP at a preconfigured granularity, which may be finer than that used for other RSRP measurements and / or reports (e.g., finer than the default RSRP measurement / reporting granularity). The network may be able to determine the WTRU's location information and / or optimize its PRS configuration based on the measured and / or reported RSRP at the finer granularity (e.g., to improve positioning accuracy). The default RSRP granularity described herein may include, for example, having no specified or configured granularity, which may indicate that the WTRU averages RSRP over resource elements (e.g., all resource elements) within the bandwidth allocated to the WTRU.

[0160] The WTRU may determine to use a default granularity for RSRP measurement and / or reporting. In an example, the granularity of RSRP measurement may be defined by resource element (e.g., RSRP per resource element), resource block (e.g., RSRP per resource block), and / or bandwidth (e.g., RSRP per bandwidth). In an example, the default granularity may include not having a configured granularity for RSRP. For example, if no granularity is specified, the WTRU may calculate a linear average of the received power of one or more resource elements over the bandwidth occupied by the PRS within the received PRS symbol.

[0161] The WTRU may determine and / or return an RSRP report with finer granularity to the network (e.g., to the LMF) under at least one of the following conditions: The WTRU may report RSRP with finer granularity than the preconfigured granularity if the WTRU detects multiple paths associated with the measurement (e.g., if the WTRU receives multiple copies of a PRS symbol at different times). The WTRU may report RSRP with finer granularity than the preconfigured granularity if the WTRU detects variation in RSRP across resource elements within a PRS symbol and / or variation (e.g., standard deviation or variance of RSRP) that is greater than or equal to a threshold configured by the network (e.g., by the LMF or gNB). In an example, if the WTRU is preconfigured to report RSRP averaged over the bandwidth occupied by the PRS, and the WTRU detects variation in RSRP across resource elements, the WTRU may report RSRP averaged over each resource block in the bandwidth occupied by the PRS. The WTRU may report the RSRP with finer granularity if the difference between the arrival times of multiple paths (e.g., the difference between the first and last path) is within the CP length of the OFDM symbol containing the PRS.

[0162] The granularity of the RSRP reports may be configured for multipath detection, for example.

[0163] The WTRU may receive configuration information from the network (e.g., from the LMF or gNB) regarding the granularity of RSRP measurements and / or reporting. The granularity of RSRP measurements and / or reporting may be defined in at least one of the following formats: The granularity may be defined such that the RSRP per symbol and the power of the received signal are averaged over resource elements within a PRS symbol (e.g., one PRS symbol). The granularity may be defined as RSRP every X RBs over at least one of the following time ranges: all received OFDM symbols containing the PRS, a preconfigured set of OFDM symbols containing the PRS, recurring occasions in the PRS resource containing the PRS, or a time range determined by the WTRU based on Doppler shift or spread, or the number of paths the WTRU detects in a multipath channel. "X" may be an integer configured by the network (e.g., the LMF). The WTRU may be given a set of values ​​for "X" and may determine which value of "X" to use depending on at least one of the number of paths the WTRU detects in the channel, the capabilities of the WTRU (e.g., whether the WTRU has the ability to report RSRP with fine resolution), or configuration received by the WTRU from the network (e.g., from the gNB or LMF) regarding which value of "X" to use.

[0164] The WTRU may be configured to have one or more of the following behaviors with respect to multipath detection (e.g., after RSRP reporting): The WTRU may decide to continue reporting RSRP with finer granularity, and may revert to default granularity (e.g., no granularity) under at least one of the following conditions: The WTRU may revert to reporting RSRP with default granularity if the number of paths is below a threshold configured by the network (e.g., by the gNB or LMF). The WTRU may revert to reporting RSRP with default granularity if the variation in RSRP across REs is below a threshold configured by the network (e.g., by the gNB or LMF).

[0165] The WTRU may be configured to have one or more of the following behaviors in connection with multipath detection (e.g., in SRSp transmission for multi-RTT): The WTRU may determine to transmit multiple SRSp resources (e.g., when using an UL and DL positioning method such as one based on multi-RTT) and may include multiple WTRU Rx-Tx time differences in the report. The WTRU may send a report to the network (e.g., to the LMF or gNB), for example, based on a condition configured by the network (e.g., based on discovering multiple paths in the channel). The WTRU may discover multiple paths in the channel based on one or more of the following conditions: The WTRU may discover multiple paths in the channel in response to detecting multiple paths in measurements (e.g., the WTRU may receive multiple copies of a PRS symbol at different times). The WTRU may discover multiple paths in the channel in response to detecting a variation in RSRP across resource elements in a PRS symbol and / or the variation (e.g., standard deviation or variance of the RSRP) being equal to or greater than a threshold configured by the network (e.g., by the LMF or gNB). The WTRU may discover multiple paths in the channel in response to detecting that there are multiple paths in the measurements and / or that the delay time between the multiple paths reported by the WTRU is equal to or greater than a threshold configured by the network. The delay time may be between the first and last path, between the first and second path, between the first path and a path associated with a path ID that may be indicated by the network (e.g., via DCI, MAC-CE, RRC signaling, or LPP messages), etc.

[0166] The multiple WTRU Rx-Tx time differences may be determined as follows: A first WTRU Rx-Tx time difference may be determined by the WTRU by at least calculating the time difference between the arrival time of a first instance of a PRS resource (e.g., PRS resource ID #1) and the transmission time of a first SRSp resource (e.g., SRSp resource ID #1), where the first SRSp resource may be a reference SRSp resource and the PRS resource may be a target PRS resource. A second WTRU Rx-Tx time difference may be determined by the WTRU by at least calculating the time difference between the arrival time of a second instance of a PRS resource (e.g., PRS resource ID #1) and the transmission time of a second SRSp resource (e.g., SRSp resource ID #2). The third WTRU Rx-Tx time difference may be determined by the WTRU by calculating at least the time difference between the arrival time of the third instance of the PRS resource (e.g., PRS resource ID #1) and the transmission time of the third SRSp resource (e.g., SRSp resource ID #3).

[0167] Resource and beam may be used interchangeably herein. In the example described herein, PRS resource ID#1 may be transmitted three or more times from the TRP, and a different SRSp resource may be transmitted each time. The different SRSp resources may correspond to different directions of the SRSp beam. In an example, the WTRU may perform beam sweeping based on the discovery of multiple paths in the channel. When multiple paths exist in the channel, the NLOS path may be from a different angle than the LOS path (e.g., as described with respect to FIG. 2). Transmitting the SRSp at a different angle may provide measurements (e.g., additional measurements) to the LMF, for example, which may improve positioning accuracy.

[0168] FIG. 5 illustrates an example in which the first, second, and third WTRU Rx-Tx time differences described herein are shown as “WTRU Rx-Tx Difference 1,” “WTRU Rx-Tx Difference 2,” and “WTRU Rx-Tx Difference 3,” respectively.

[0169] For example, upon discovery of multiple paths in the channel, the WTRU may determine / transmit multiple SRSp via respective SRSp resources (e.g., N SRSp resources, where N is an integer configured by the network, such as LMF or gND). One or more of the following may be performed: The WTRU may transmit the SRSp on the N-1 SRSp resources, which may correspond to adjacent beams of the reference SRSp resource. The WTRU may choose (e.g., select) the SRSp based on spatial direction information (e.g., azimuth angle, elevation angle, etc.) associated with the DL-PRS resource and spatial relationship information associating the SRSp resource with the DL RS.

[0170] The WTRU may receive spatial information from the network associating the target PRS resource with the N SRSp resources, including the reference SRSp resource. The WTRU may receive angle information from the network, which may include one or more of the following: The angle information may include a predicted AoD and / or an indication of the AoD (e.g., a range of AoD, with the center of the range indicating the predicted AoD) of the reference SRSp resource. The angle information may include a predicted AoA and / or an indication of the AoA (e.g., a range of AoA, with the center of the range indicating the predicted AoA) of the target PRS resource.

[0171] The number N of SRSp resources that the WTRU can use for transmission may be explicitly configured by the network (e.g., by the LMF or gNB) or may be implicitly configured (e.g., by spatial information). The WTRU may include (e.g., in a measurement report) an SRSp resource ID and / or an SRSp resource set ID associated with multiple Rx-Tx values ​​(e.g., each of multiple Rx-Tx values). For example, "WTRU Rx-Tx Difference 2" as described with respect to FIG. 5 may be associated with SRSp resource #2.

[0172] The WTRU may report (e.g., based on detection of multiple paths in the channel) a WTRU Rx-Tx difference of the receive time (e.g., with respect to slot #, subframe #, frame #, symbol #) of one or more PRS resources (e.g., each PRS resource) with respect to the transmit time (e.g., with respect to slot #, subframe #, frame #, symbol #, absolute time, time relative to a reference time) of different PRS resources. For example, the WTRU may report (e.g., send an indication) (e.g., to a network entity) the WTRU Rx-Tx difference of the receive time of PRS resource #1 with respect to the transmit time of SRSp resource #2, the WTRU Rx-Tx difference of the receive time of PRS resource #2 with respect to the transmit time of SRSp resource #2, the WTRU Rx-Tx difference of the receive time of PRS resource #3 with respect to the transmit time of SRSp resource #2, etc.

[0173] The WTRU may be configured to receive one or more of the following from the network (e.g., from the LMF or gNB): The WTRU may be configured to receive an instruction to associate a set of PRS resources and / or a path (e.g., a path ID such as a LOS path ID and / or a NLOS path ID) with an SRSp (e.g., a respective SRSp resource). The WTRU may be configured to transmit one or more SRSp resources having respective IDs. The WTRU may be configured to receive spatial relationship configuration information from the network, which may indicate a DL PRS associated with the SRSp, an SRSp transmission direction, and / or a receiving beam and / or direction. In an example, the spatial relationship may be an association of an SRSp resource ID with a DL PRS resource ID, indicating that the PRS on the PRS resource and the SRSp on the SRSp resource are transmitted and / or received in the same direction. The WTRU may be configured to receive one or more PRS resources, and the WTRU may detect multiple paths (e.g., based on measurements made on the received PRS on the PRS resource, such as time of arrival or angle of arrival). The WTRU may be configured to assign path IDs to paths (e.g., assign respective path IDs to respective paths) and / or associate path IDs (e.g., respective path IDs) with SRSp IDs (e.g., respective SRSp IDs), e.g., based on matching path direction and / or SRSp spatial relationship information received by the WTRU. The WTRU may be configured to transmit the association of path IDs to SRSp IDs to the network. The WTRU may be configured, e.g., for a path ID (e.g., each path ID) and / or based on the association of path IDs to SRSp IDs, to transmit an SRSp in an SRSp resource having an associated SRSp ID. The WTRU may determine an Rx-Tx time difference from reception of the PRS to transmission of the SRSp, which may be associated with the path / path ID (e.g., a respective SRSp may be transmitted for each of a first path and a second path, and each path may include a respective path ID).The WTRU may report (eg, to the network) each Rx-Tx time difference (for each path / path ID).

[0174] 6 illustrates an example of a spatial relationship configuration associating a PRS with an SRSp. In the example, three SRSp resources (e.g., SRSp1, SRSp2, and SRSp3) may be associated with a PRS resource (e.g., PRS1). The WTRU may receive configuration information from the network (e.g., gNB, LMF, etc.) that may associate the PRS resource (e.g., PRS1) with one or more of the SRSp resources (e.g., all of the SRSp resources, such as SRSp1, SRSp2, and / or SRSp3). The WTRU may report Rx-Tx differences for one or more paths (e.g., path-dependent Rx-Tx reporting). For example, the WTRU may report an Rx-Tx difference based on the arrival time or reception time of a PRS received from the direction of path 2 (e.g., as shown in FIG. 6) (received based on PRS resource PRS1) relative to the transmission time of an SRSp associated with path 2 (e.g., SRSp is transmitted based on SRSp resource SRSp1 toward the direction of path 2). The WTRU may use an Rx beam steered toward SRSp resource SRSp1 and, for example, may use the Rx beam to measure the arrival time of the received PRS. The WTRU may report an Rx-Tx difference based on the arrival time of a PRS along path 1 (e.g., as shown in FIG. 6) (received using PRS resource PRS1) relative to the transmission time of an SRSp associated with path 1 (e.g., SRSp may be transmitted using SRSp resource SRSp2). The WTRU may use an Rx beam steered towards SRSp resource SRSp2 and may use the Rx beam to measure the arrival time of the received PRS.In an example, the WTRU may report (e.g., send an indication thereof) (e.g., to a network entity) the WTRU Rx-Tx difference of the reception time of the PRS on PRS resource PRS1 received along path 1 relative to the transmission time of the SRSp on SRSp resource SRSp2 transmitted along path 1, and the WTRU Rx-Tx difference of the reception time of the PRS on PRS resource PRS1 received along path 1 relative to the transmission time of the SRSp on SRSp resource SRSp1 transmitted along path 2, etc.

[0175] FIG. 7 illustrates how a WTRU can determine an Rx-Tx difference. The WTRU can determine the presence of multiple paths (e.g., multiple transmit / receive paths), for example, if a PRS is received via multiple paths (e.g., using PRS resources) within a time window (e.g., a preconfigured time window). The WTRU can receive configuration information regarding the time window from the network (e.g., from a base station or gNB, from an LMF, etc.). In an example, the configuration information may indicate that the duration of the time window is 2 milliseconds (ms). The WTRU can assign a path ID to the detected paths (e.g., each detected path), for example, if the WTRU makes measurements on multiple copies of the PRS (e.g., PRS resources used to transmit the PRS) within the time window. In an example, the WTRU can be configured to not include PRS resources with arrival times outside the time window in determining the multiple paths.

[0176] The WTRU may be configured with one or more of the following behaviors with respect to terminating actions performed in connection with multipath detection (e.g., after performing RSRP reporting as described herein): The WTRU may report the WTRU Rx-Tx difference for a reference SRSp resource (e.g., a single reference SRSp resource), and for example, the WTRU may switch back to the default reporting behavior if one or more of the following conditions are met: the number of paths falls below a threshold configured by the network (e.g., by the gNB or LMF), the RSRP variation across the REs is equal to or less than a threshold configured by the network (e.g., by the gNB or LMF), or the WTRU receives an instruction from the network (e.g., via DCI, MAC-CE, RRC signaling, or LPP message) to report the WTRU Rx-Tx difference for the reference SRSp resource.

[0177] As described herein, the WTRU may use a first positioning method (e.g., based on multi-RTT with a single SRSp resource for reporting Rx-Tx time differences). The WTRU may switch (e.g., autonomously switch) to a second positioning method based on a condition being met (e.g., detection of multiple paths in the channel). The second positioning method may, for example, be based on multi-RTT with N SRSp resources (e.g., including a reference SRSp resource) for reporting Rx-Tx time differences. The WTRU may switch back to the first positioning method based, for example, on an exit condition being met (e.g., the WTRU no longer observes multiple paths in the channel).

[0178] The WTRU may be configured to perform WTRU-based positioning in the presence of multiple paths. WTRU-based DL positioning (e.g., based on TDOA or AoD) may include the WTRU calculating its position based on measurements made on received PRSs and reporting the WTRU's location information to the network (e.g., LMF). The WTRU may not need to send measurement reports to the network (e.g., LMF). In examples (e.g., when there are multiple paths observed by the WTRU in one or more PRSs, such as one or more PRS beams and / or PRS resources received by the WTRU), the WTRU may not be able to indicate to the network (e.g., LMF) the existence of multiple paths in the channel, which may result in reduced positioning accuracy for the WTRU. The PRSs (e.g., PRS beams and / or PRS resources) may belong to different PRS resource sets and / or be associated with different TRPs, absolute radio-frequency channel numbers (ARFCNs), PRS-IDs, cell IDs, and / or CellGlobalIDs.

[0179] The WTRU may receive one or more criteria and / or conditions from the network for using a single-path-based location estimate. The WTRU may determine / use to use measurements corresponding to a path to derive a location estimate, for example, if a minimum number of measurements are available (e.g., measurements related to RSRP and time of arrival are available for the path) or if a condition is met (e.g., the RSRP of the path exceeds a threshold, the relative difference between the RSRP of the path and the RSRP of other detected paths exceeds a threshold, etc.). The WTRU may report the location estimate to the network (e.g., LMF) and may indicate to the network (e.g., LMF) that single-path measurements are used to derive the location estimate. The WTRU may switch to multi-path-based derivation of a location estimate, for example, if one or more of the criteria or conditions are not met.

[0180] The WTRU may receive one or more criteria from the network for multipath-based location estimation. The WTRU may derive a location estimate based on the criteria and may report the location estimate to the network (e.g., to the LMF). In an example, the WTRU may detect multiple paths in a channel. The WTRU may report the number of detected paths along with location information to the network. The WTRU may transmit the location information and / or multipath information via a message, such as an LPP message (e.g., a "Provide LPP Location Information" message).

[0181] The WTRU may determine to report multiple location information, for example, if the WTRU detects multiple paths in a channel for at least one of the PRSs that the WTRU receives and on which the WTRU makes measurements. The WTRU may determine criteria used to derive the location information and may report the location information to the network (e.g., to the LMF). The WTRU may determine to include single location information, for example, if the WTRU does not detect multiple paths in a channel. The WTRU may receive instructions from the network (e.g., from the LMF) to report single and / or multiple location information (e.g., via DCI, MAC-CE, RRC signaling, LPP messages, etc.).

[0182] The WTRU may report multiple location information (e.g., based on detecting multiple paths) and / or may associate the location information with criteria used by the WTRU to derive the location information. In an example (e.g., when using methods such as TDOA or AoD), the WTRU may make measurements on multiple PRSs and observe multiple paths on one or more of the PRSs. The WTRU may report multiple location information and / or its association with paths to the network (e.g., to the LMF) based on detecting multiple paths in the channel or based on instructions from the network (e.g., from the LMF) to report multiple location information and its association with multiple paths.

[0183] In an example, the WTRU may detect Ni paths in the channel of PRS resource #i (e.g., which may be associated with PRS beam #i). The WTRU may derive location information using one or more of the following and may indicate to the network (e.g., LMF) that the location information provided to the network (e.g., LMF) is derived using one or more of the following:

[0184] The WTRU may derive location information based on one or more paths (e.g., all paths) that the WTRU observes in measurements associated with one or more PRS resources (e.g., all PRS resources). In an example, the WTRU may derive location information based on Ni paths (e.g., all Ni paths) of PRS resource i for values ​​of / (e.g., all values ​​of i) on which the WTRU makes measurements, where i may be an index of the PRS resource configured by the network (e.g., LMF) and / or detected by the WTRU.

[0185] The WTRU may derive location information based on paths determined based on one or more of the following criteria: The criteria may be applicable to one or more PRS resources (e.g., all PRS resources) on which the WTRU makes measurements. The criteria may be configured by the network (e.g., by the LMF). The WTRU may determine location information based on the path with the highest RSRP among the Ni paths that the WTRU detects for PRS resource index / (e.g., PRS resource index i). The WTRU may determine location information based on the path with the earliest arrival time (e.g., the first path) among the Ni paths that the WTRU detects for PRS resource index i (e.g., each PRS resource index i). The WTRU may determine location information based on paths with an indicated arrival order. In an example, the WTRU may determine location information based on the path with the second earliest arrival time and may indicate to the network that this path is to be used to derive location information. The WTRU may determine location information based on measurements associated with one or more paths (e.g., one or more observed paths for each PRS resource index i). In an example, if the relative delay of one or more paths compared to the path with the earliest ToA is less than or equal to a preconfigured threshold, which may be configured by the network, e.g., the LMF or gNB, the WTRU may determine location information using measurements associated with the one or more paths. In an example, if the relative RSRP difference of one or more paths compared to the path with the strongest RSRP is less than or equal to a preconfigured threshold (which may be configured by the network, e.g., the LMF or gNB), the WTRU may determine location information using measurements associated with the one or more paths.

[0186] The WTRU may derive location information based on one or more selected paths, and the WTRU may report measurements associated with the selected paths (e.g., RSRP, relative time difference to the arrival time of a reference path, etc.).

[0187] The conditions and / or criteria described herein may be configured by the network (e.g., by the LMF). The WTRU may receive the configuration, for example, before receiving the PRS. The WTRU may receive the configuration, for example, if the WTRU reports the presence of multiple paths in the channel. The WTRU may receive an indication from the network (e.g., the LMF) regarding which one or more criteria to use. The indication may be received, for example, via DCI, MAC-CE, RRC signaling, LPP messages, etc.

[0188] In an example, a WTRU may be configured by the network (e.g., by the LMF) to receive a first PRS resource (e.g., PRS resource #1), a second PRS resource (e.g., PRS resource #2), and / or a third PRS resource (e.g., PRS resource #3), which may be transmitted by different TRPs located at different locations. From the WTRU's perspective, each PRS beam corresponding to a PRS resource may be transmitted from a different direction. The WTRU may observe one, three, and two paths based on measurements made for PRS resource #1, PRS resource #2, and PRS resource #3, respectively. Based on the maximum RSRP criterion described herein, the WTRU may select the path from which the maximum RSRP is obtained among the three and two paths detected in the measurements for PRS resource #2 and PRS resource #3, respectively, and may derive location information using measurements (e.g., RSRP, time of arrival, angle of arrival, etc.) from the selected path. Since one path (eg, only one path) is observed in the measurements taken from PRS resource #1, the WTRU may use the measurements for that path to derive location information.

[0189] The WTRU may indicate to the network (e.g., to the LMF) path information (e.g., PRS resource IDs over which the WTRU observes multiple paths) used to derive location information. The WTRU may receive instructions from the network (e.g., from the LMF and / or via an LPP message) for the WTRU to report multiple location information corresponding to different criteria. The WTRU may report multiple location information based on one or more of the criteria or conditions described herein. In an example, the WTRU may report one location information obtained using the maximum RSRP criterion and another location information obtained using the earliest arrival time criterion.

[0190] The WTRU may include one or more of the following in its report to the network (e.g., to the LMF): The WTRU may include expected location information and / or an indication of location information (e.g., lower and upper location bounds for the expected location information) in its report to the network. The WTRU may include one or more PRS resource IDs over which the WTRU detects multiple paths (e.g., based on measurements performed by the WTRU) in its report to the network.

[0191] For WTRU-based AoD-based positioning, the WTRU may report expected location information and an indication associated with the location information (e.g., lower and upper bounds of the location information, standard deviation or variance of the location information, etc.) to indicate to the network (e.g., to the LMF) measurement uncertainty due to multiple paths observed in measurements performed on PRS resources received by the WTRU. The WTRU may receive configuration information from the network to report expected location information and / or location information uncertainty.

[0192] The WTRU may be configured to determine an RSRP associated with a transmit / receive path (e.g., a first path). The WTRU may receive a request from the network to report the RSRP. In an example (e.g., when the WTRU is configured to apply a WTRU-assisted positioning technique such as DL-AoD, DL-TDOA, etc.), the WTRU may receive an instruction from the network to report a first path RSRP associated with one or more PRS resources on which the WTRU is configured to measure (e.g., multiple paths may be detected for one or more PRS resources). In an example (e.g., when the WTRU is configured to apply a WTRU-based positioning technique such as DL-AoD, DL-TDOA, etc.), the WTRU may receive an instruction from the network to use the first path RSRP to determine a location estimate (e.g., the first path RSRP may be associated with one or more PRS resources for which multiple paths are detected). The WTRU may receive the instruction described herein via an LPP message, via RRC signaling, in a MAC-CE or DCI, etc.

[0193] If the WTRU is able to detect multiple paths, the WTRU may send a message (e.g., an acknowledgement message in response to receiving an instruction to report the first path RSRP) to the network, e.g., via LPP, RRC signaling, MAC-CE, or UCI. If the WTRU is unable to detect multiple paths, the WTRU may send a response (e.g., a NACK message) to the network (e.g., via LPP, RRC signaling, MAC-CE, or UCI) indicating a lack of capability. The WTRU may send capability information associated with detecting multiple paths (e.g., including the ability to measure the first path RSRP) to the network, e.g., before receiving an instruction from the network to report and / or use the first path RSRP for location estimation.

[0194] The WTRU may select a path (e.g., a first path) with an earliest arrival time from multiple paths (e.g., Ni paths) that the WTRU may detect for a PRS resource (e.g., each PRS resource, such as the PRS resource associated with PRS resource index i). The WTRU may use the selected path for location estimation, e.g., if the WTRU is configured to apply a WTRU-based positioning technique for location estimation. The WTRU may use the selected path for RSRP reporting (e.g., RSRP measured for the PRS associated with the path), e.g., if the WTRU is configured to apply a WTRU-assisted positioning technique, such as DL-AoD, DL-TDoA, etc.

[0195] If the WTRU receives an instruction from the network to report a first path RSRP and the WTRU does not detect multiple paths for one or more PRS resources, the WTRU may report the RSRP for the one or more PRS resources. The WTRU may be configured, for example, to not include an indication that the reported RSRP corresponds to the first path (e.g., or to indicate that the reported RSRP is not associated with the first path) if the WTRU does not detect multiple paths for the one or more PRS resources.

[0196] When generating (e.g., measuring and / or reporting) the RSRP of the first path, the WTRU may be configured to do one or more of the following: The WTRU may report the cumulative or average received power (e.g., RSRP) for the first path over a time window or several time units (e.g., symbols, PRS resources, slots, frames, or other time units), and consistent measurements may be reported and / or used by the WTRU for location estimation. The duration of the time window or the number of time units may be pre-configured, for example, by the network. When the WTRU reports the RSRP of the first path to the network, the WTRU may include a PRS resource ID associated with the measured RSRP of the first path. The WTRU may indicate in the report that the reported RSRP corresponds to the first path of the PRS resource ID.

[0197] The WTRU may be configured (e.g., by the network) to make measurements on multiple paths during a time window (e.g., a preconfigured time window). The duration of the time window may be based on channel characteristics such as delay spread. In an example, the WTRU may be configured with two time windows and may receive configuration for the time windows (e.g., duration, start time, end time, periodicity, etc.). The WTRU may use a first time window (e.g., of the two configured time windows), the duration of which may be determined based on the delay spread of the channel, to determine, for example, the number of paths the WTRU may measure. For example, the WTRU may be preconfigured with a lookup table that associates the duration of the window with the delay spread of the channel. Based on the measured spread value, the WTRU may consult the lookup table and determine the duration of the window. The WTRU may be configured to not consider replicas (e.g., any replicas) of the PRS received by the WTRU beyond the duration of the first time window as part of multiple paths. The PRS may be transmitted by the network (e.g., by a base station or gNB, by a TRP, etc.) periodically or semi-persistently, with or without repetition.

[0198] The WTRU may use the second time window (e.g., of two configured time windows described herein) to accumulate the received power of PRS (e.g., transmitted periodically or semi-persistently from the network and received by the WTRU) to detect paths and / or report RSRP (e.g., per path) to the network. The WTRU may include the duration of the first and / or second time windows if the WTRU reports accumulated RSRP (e.g., or averages RSRP per path). The WTRU may assign a path ID to paths (e.g., each path) detected during the first time window and associate the path (e.g., path ID) with the average / accumulated RSRP measured for the path.

[0199] In an example, the WTRU may accumulate RSRP for paths (e.g., each path) that the WTRU detects in the first time window during a second time window described herein. In an example, the WTRU may not accumulate RSRP, for example, if the RSRP is below a preconfigured threshold. The WTRU may be configured with a second time window for each path in the multipath channel. For example, if the WTRU detects three paths in the channel, the WTRU may receive a window configuration from the network that may be applicable to each of the three paths detected by the WTRU. The WTRU may associate the detected paths with a relative delay relative to the first path and may report the number of paths, the RSRP, and the relative delay to the network (e.g., the LMF or gNB). For example, with respect to the first path (e.g., the path along which the earliest arrival time of the PRS is measured), the WTRU may determine to associate the second path with a delay T1 that indicates that the WTRU will receive the PRS T1 later than the time the PRS was received along the first path. The WTRU may determine to associate the third path with a delay T2, indicating that the WTRU receives the PRS along the third path T2 after the time the PRS was received along the first path, where the units of delay may be expressed in terms of seconds, number of symbols, slots, frames, or subframes.

[0200] The WTRU may, for example, declare a path to be part of multiple channels if the RSRP (e.g., accumulated or averaged over the second time window) exceeds a preconfigured threshold. The WTRU may, for example, not declare a path to be part of multiple channels if the RSRP (e.g., accumulated or averaged over the second time window) exceeds a preconfigured threshold.

[0201] In an example (e.g., based on the expiration of the second time window), the WTRU may determine the first path based on the earliest arrival time during the first time window. In an example, if the accumulated / averaged RSRP corresponding to the earliest path within the time window is below a preconfigured threshold, the WTRU may determine that the next earliest path within the time window having an accumulated / averaged RSRP above the preconfigured threshold is the first path.

[0202] The WTRU may use the first and / or second time windows described herein to accumulate or average RSRPs, for example, even if the WTRU does not detect multiple paths associated with a PRS. For example, the WTRU may accumulate or average RSRPs for observed PRSs.

[0203] The WTRU may repeat the operations described herein for multiple PRS resources (eg, all PRS resources) in the PRS resource set configured for the WTRU.

[0204] A WTRU-assisted or WTRU-based positioning technique may be based on the first path.

[0205] In an example (e.g., in the case of WTRU-based positioning), the WTRU may indicate to the network that a location estimate is obtained based on one or more of the following: The WTRU may indicate that a location estimate is obtained using a first path RSRP (e.g., only the first path RSRP). The WTRU may indicate that a location estimate is obtained using a combination of the first path RSRP and the RSRP of PRS resources for which multiple paths were not detected. The WTRU may indicate that none of the RSRPs used to derive the location estimate are first paths.

[0206] In an example (e.g., in the case of WTRU-assisted positioning), the WTRU may indicate (e.g., to the network) the associated PRS resource ID, PRS resource set ID, TRP ID, and / or frequency layer ID from which the first path RSRP is obtained.

[0207] The WTRU may be configured to measure multiple PRS resources in a PRS resource set. The PRS resources (e.g., each PRS resource) may be transmitted using a respective Tx beam (e.g., a different Tx beam), which may be aimed in a different direction from the transmitter side. The beam associated with the PRS resource may be pointed along the LOS direction (e.g., as described with respect to FIG. 2). The WTRU may determine to report and / or use the first path RSRP for location estimation for WTRU-assisted or WTRU-based positioning, respectively. The WTRU may determine the first path RSRP to report / use for location estimation based on one or more of the following criteria:

[0208] The WTRU may report and / or use the RSRP of the first path corresponding to (e.g., each) PRS resource (e.g., the WTRU may measure the arrival time for the PRS resource and / or, if the WTRU detects multiple paths for the PRS resource, measure the RSRP of the PRS resource with the earliest arrival time). In an example, if the WTRU does not detect multiple paths, the WTRU may, for example, report the RSRP of the PRS without associating the RSRP with a path.

[0209] The WTRU may measure a first path RSRP for a PRS resource for which the WTRU detects multiple paths. The WTRU may measure the RSRP for a PRS, for example, if the WTRU detects a path (e.g., a single path) for the PRS. The WTRU may determine the highest RSRP among the first path RSRP and the RSRP for the PRS resource. The WTRU may report the highest RSRP to the network (e.g., for WTRU-assisted positioning) or use the highest RSRP for location estimation (e.g., for WTRU-based positioning).

[0210] The WTRU may select a first path RSRP from a PRS resource for which multiple paths are detected, and may report and / or use the highest first path RSRP among the first path RSRPs described herein obtained for the PRS resource.

[0211] The WTRU may measure the arrival time and / or RSRP for a PRS resource (e.g., each PRS resource). The WTRU may measure multiple arrival times for a PRS resource, for example, if multiple paths are detected for the PRS. The WTRU may determine the PRS resource with the earliest arrival time over the measured arrival times for multiple PRS resources (e.g., all PRS resources) in a PRS resource set, and report / use the RSRP along with the associated PRS ID and / or PRS resource set ID.

[0212] In the examples described herein, "RSRP" may be replaced by "averaged RSRP" or "accumulated RSRP." The WTRU may determine the first path, averaged RSRP, or accumulated RSRP using the first and / or second time windows described herein. The WTRU may determine the presence of multiple paths using the first and / or second time windows described herein. The WTRU may repeat the operations described herein for one or more PRS resource sets (e.g., for each PRS resource set) and / or one or more TRPs (e.g., for each TRP) from which the PRS is transmitted, such that the WTRU may determine a first path ID for the PRS resource set and / or TRP. The WTRU may report the first path RSRP for one or more PRS resource sets (e.g., for each PRS resource set) and / or one or more TRPs (e.g., for each TRP), e.g., for WTRU-assisted positioning. The WTRU may include an arrival time corresponding to the first path for the PRS, where, for example, the arrival time may be expressed in terms of a system frame number, a slot number, an absolute radio frequency channel number, a cell global ID, a physical cell ID, a subframe number, and / or a symbol number.

[0213] The WTRU may be configured with multiple sets of PRS resources, and the WTRU may receive a request from the network to report a first path RSRP and / or use the first path RSRP for location estimation. The WTRU may measure the arrival time and / or RSRP for PRS resources (e.g., each PRS resource) within a resource set (e.g., each resource set). The WTRU may measure multiple arrival times for PRS resources, for example, if multiple paths are detected for a PRS. The WTRU may determine the PRS resource with the earliest arrival time over the arrival times measured for multiple PRS resources (e.g., all PRS resources) within the multiple resource sets (e.g., all resource sets). The WTRU may report / use the RSRP associated with the PRS resource along with the associated PRS ID and / or PRS resource set ID.

[0214] The WTRU may be configured to perform single-path-based location estimation. In an example, the WTRU may determine to use measurements from one or more PRS resources from which the WTRU does not observe multiple paths. The WTRU may be configured by the network (e.g., by an LMF) to receive, for example, a first PRS resource (e.g., PRS resource #1), a second PRS resource (e.g., PRS resource #2), a third PRS resource (e.g., PRS resource #3), and / or a fourth PRS resource (e.g., PRS resource #4), which may be transmitted from different TRPs located at different locations. From the WTRU's perspective, the PRS beams corresponding to each PRS resource may be transmitted from different directions. The WTRU may observe one path, three paths, one path, and one path from measurements made on PRS resource #1, PRS resource #2, PRS resource #3, and PRS resource #4, respectively. The WTRU may, for example, in such a case, decide to use PRS resources #1, #2, and #4 to determine a location estimate and may reject measurements from PRS resource #3, for example, due to the presence of multiple paths in the measurement. The WTRU may indicate to the network (e.g., to the LMF) that a received PRS from which only a single path is measured is to be used to derive a location estimate.

[0215] The WTRU may determine to perform single-path-based location derivation or multi-path-based location derivation as described herein based on one or more conditions. The WTRU may use single-path-based location derivation, for example, if one or more of the following conditions are satisfied: The WTRU may use single-path-based location derivation if the number of PRS resources from which a single path is observed is greater than or equal to a preconfigured threshold (e.g., configured by the network, such as the LMF or gNB). In an example, a minimum number of measurements may be available for the WTRU to derive a location estimate. The WTRU may use single-path-based location derivation if the minimum or average RSRP of the received PRS resources from which a single path is observed is greater than or equal to a preconfigured threshold (e.g., configured by the network, such as the LMF or gNB). In an example, the received signal power may be large enough for the WTRU to derive a location estimate. The WTRU may use single-path-based location derivation if, for one or more PRS resources (e.g., all PRS resources) from which two or more paths are observed, the relative time difference between the first path (e.g., having the earliest arrival time) and the last path (e.g., having the latest arrival time) is less than or equal to a preconfigured threshold (e.g., configured by the network, such as the LMF or gNB). In an example, multiple paths arriving close enough in time to each other may be considered a single path. The WTRU may use single-path-based location derivation if one of the paths is indicated as line-of-sight from the network. The WTRU may determine to perform (e.g., switch to performing) the multiple-path-based location derivation described herein if, for example, none of the conditions are met.

[0216] If single-path based measurements are used, the WTRU may indicate to the network (e.g., LMF) that single-path based derivation of a location estimate is to be used, and the WTRU may indicate which one or more criteria are to be used to determine which method is to be used to derive a location estimate.

[0217] If multipath-based measurements are used, the WTRU may indicate to the network (e.g., the LMF) that multipath-based derivation of a location estimate will be used, and the WTRU may indicate which one or more criteria are used to determine which method is used to derive a location estimate. The WTRU may receive an indication (e.g., an explicit indication) from the network (e.g., from the LMF) regarding whether the WTRU should use single-path or multipath-based measurements to derive location information. The indication may be received, for example, via DCI, MAC-CE, RRC signaling, LPP messages, etc.

[0218] Conditions or criteria related to multi-path-based location estimate derivation may be configured separately from conditions or criteria related to single-path-based location estimate derivation. For example, if the WTRU determines that single-path-based location estimate derivation cannot be used by the WTRU, the WTRU may request that the network (e.g., the LMF) send configuration information related to the conditions or criteria to the WTRU.

[0219] The WTRU may be configured with one or more of the following behaviors in connection with detecting multipath and / or angle-based positioning: In the case of angle-based positioning (e.g., AoD), timing information of the multipath channel may not be available, and the network may not be able to obtain direction information for one or more paths (e.g., for each of the one or more paths).

[0220] The WTRU may observe multiple paths in the channel (e.g., through RSRP at finer resolution). The presence of multiple paths in the channel may correspond to frequency selectivity in the channel. For example, if the RSRP of the PRS is averaged over the bandwidth occupied by the PRS, the WTRU may not observe frequency selectivity of the channel. The WTRU may observe frequency selectivity, for example, if the RSRP is averaged per resource block within the bandwidth occupied by the PRS. The WTRU may determine the number of Rx beams that the WTRU may use for Rx beam sweeping. The WTRU may, for example, perform Rx sweeping using the determined number of Rx beams and / or report RSRP per Rx beam for the PRS resource (e.g., at finer granularity). The WTRU may indicate to the network that beam sweeping is occurring and that the WTRU's orientation has not changed.

[0221] In an example, the WTRU may detect multiple paths and determine the number of Rx beams to be used for Rx beam sweeping. The number of Rx beams may be determined by one or more of the following: a distribution of RSRPs across the frequency domain, an uncertainty range configured by the network, a predicted AoD of the DL-PRS from the network (e.g., from the LMF), or a value configured by the network. In an example, the uncertainty range may include the predicted AoD and / or uncertain AoD (e.g., a range of AoDs, with the center of the range indicating the predicted AoD) associated with the reference SRSp resource. In an example, the uncertainty range may include the predicted AoA and / or uncertain AoA (e.g., a range of AoAs, with the center of the range indicating the predicted AoA) of the target PRS resource.

[0222] The WTRU may be configured to report RSRP and / or other quantities (e.g., phase difference relative to a reference Rx for each Rx beam) (e.g., at a finer granularity compared to a pre-configured granularity for reporting RSRP). The WTRU may indicate (e.g., explicitly indicate) that it did not rotate. The WTRU may report a relative AoA (e.g., relative to a reference point such as Rx beam 1) for additional measurements or additional paths (e.g., for each additional measurement or additional path).

[0223] The WTRU may not be expected to rotate during an Rx beam sweep, and the WTRU may indicate to the network that its orientation has not changed.

[0224] The WTRU may be configured to perform TEG measurements and / or reporting. As referred to herein, a TEG may include transmit and / or receive parameters (e.g., beams, panels, ports, etc.) used by a WTRU associated with the TEG.

[0225] The WTRU may be configured to group different timing errors into a TEG based on, for example, the QoS requirements of the positioning service. The QoS requirements may include, for example, a positioning accuracy requirement. In an example, the WTRU may group one or more UL transmissions or DL ​​receptions into a TEG if the timing error between any UL transmission and DL reception in the group is below a threshold. The threshold may be determined based on one or more QoS requirements of the positioning service (e.g., a positioning accuracy requirement). In an example, the WTRU may be associated with multiple antenna panels for UL-PRS transmissions for positioning use. For low positioning accuracy requirements, the WTRU may group UL-PRS transmissions of different antenna panels into a TEG. For high positioning accuracy requirements, the WTRU may group UL-PRS transmissions of the same antenna panel into a TEG. For more stringent positioning accuracy requirements, the WTRU may group UL-PRS transmissions of one antenna port into a TEG. An antenna port (e.g., each antenna port) may be associated with (e.g., one) TEG (e.g., a respective TEG).

[0226] The WTRU may be configured to determine an association between a TEG and UL-PRS and / or DL-PRS resources. In an example, the WTRU may be indicated (e.g., via network configuration) an association between a TEG and a set of resources (e.g., DL-PRS reception resources or UL-PRS transmission resources). The WTRU may use the same set of transmission and / or reception parameters (e.g., corresponding to the same TEG) for the set of resources for transmission and / or reception (e.g., based on the indicated association). In an example, the WTRU may use an Rx beam to represent the TEG. In an example, the WTRU may be indicated (e.g., configured) to use the same TEG for reception of a set of DL-PRS resources, and the WTRU may use the same Rx beam for DL-PRS reception on the indicated set of resources. In an example, the WTRU may be indicated (e.g., configured) to use the same TEG for a set of UL-PRS transmissions. The WTRU may associate an antenna panel with the TEG, and the WTRU may use the antenna panel (eg, one antenna panel) for UL-PRS transmissions on the indicated set of UL-PRS resources.

[0227] A WTRU may be configured (via RRC signaling) or indicated (e.g., via DCI) to use the same TEG for a set of DL-PRS and / or UL-PRS resources. In an example, the WTRU may be configured to use TEG transmission / reception for the set of resources. In an example, the WTRU may determine to use a beam or panel for reception of a set of DL-PRS resources. This may help the network to offset one or more TEGs associated with the same source (e.g., the same beam reception).

[0228] A WTRU may be configured (e.g., via RRC signaling) or indicated (e.g., via DCI) to use multiple TEGs for DL-PRS reception and / or UL-PRS transmission. In an example, the WTRU may determine to use multiple TEGs for DL-PRS reception and / or UL-PRS transmission on a set of resources. In an example, the WTRU may be configured to perform beam-sweeping reception for DL-PRS reception on the set of resources and / or beam-sweeping transmission for UL-PRS transmission on the set of resources. This may help the WTRU average out timing errors from the WTRU side.

[0229] The WTRU may be configured to report TEG information to the network. The WTRU may perform one or more of the following TEG information reporting: The WTRU may perform periodic TEG reporting. In an example, the WTRU may be configured to transmit TEG information periodically, where the periodicity may be configured based on a positioning service. The WTRU may be configured to perform trigger-based reporting and may report TEG information based on one or more of the following events (e.g., triggering events): detection of a delta difference from a previous TEG report, or use of a different set of TEGs to perform DL-PRS reception and / or UL-PRS transmission (e.g., the WTRU may perform TEG reporting when using different ports, beams, or antenna panels to transmit UL-PRS and / or receive DL-PRS).

[0230] The WTRU may be configured to request TEG information of a base station (e.g., a gNB). The WTRU can request that the TEG information of the base station (e.g., a gNB) be used, for example, in a WTRU-based positioning method. The WTRU may be configured with one or more triggering events to send the TEG information request. The triggering events may include one or more of a positioning error being greater than a threshold or a variation in a location measurement being greater than a threshold.

[0231] The WTRU may be configured to receive TEG information from the network. The WTRU may receive TEG information from the network (e.g., for gNB Tx and / or Rx TEG) for use in WTRU-based positioning methods. The TEG information may be provided to the WTRU by, for example, the LMF and / or in an assistance information exchange technique. The WTRU may receive a flag indicating that the TEG is not configured. The WTRU may not receive a TEG configuration at the start of operation, in which case the WTRU may assume a default time error or no time error.

[0232] The WTRU may be configured to determine which resources to use to perform positioning measurement reporting. In an example, the WTRU may be configured to perform TEG-based positioning measurement reporting and may use multiple TEGs (e.g., multiple beams, panels, or antenna ports) to measure DL-PRS. The WTRU may determine to perform positioning measurement reporting (e.g., RSTD, RSRP, etc.) for resources associated with a TEG (e.g., only one TEG). This may help the network (e.g., LMF) to offset one or more TEGs, as the TEGs associated with one or more resources (e.g., each resource) may be similar.

[0233] The WTRU may be configured to determine the validity of the TEG information. In an example, the WTRU may be provided with the TEG information by the network. The WTRU may receive an indication (e.g., from the network) regarding the validity of the TEG information. The WTRU may perform one or more of the following, for example, based on expiration of the validity of the TEG information: The WTRU may request new TEG information. The WTRU may discard old TEG information from positioning calculations and / or reporting.

[0234] The WTRU may indicate the validity of the TEG information to the network. An indication may be provided in the TEG report. The WTRU may trigger a TEG report, for example, based on the expiration of a previous TEG report.

[0235] The WTRU may be configured to determine whether to include TEG information in a positioning measurement report. The WTRU may determine whether to include TEG information in a positioning measurement report based on one or more of the following: The WTRU may determine whether to include TEG information in a positioning measurement report based on the number of TEGs the WTRU uses for DL_PRS reception and / or UL-PRS transmission. For example, if the WTRU uses at least two TEGs for DL-PRS transmission and / or UL-PRS transmission, the WTRU may report TEG information in the positioning measurement report. The WTRU may determine whether to include TEG information in a positioning measurement report based on the TEGs the WTRU uses in a previous reporting operation. For example, if the WTRU uses the same TEG as in the previous reporting operation, the WTRU may not provide TEG information in the positioning measurement report. For example, the WTRU may provide TEG information in the positioning measurement report if the WTRU does not use the same TEG as in the previous reporting operation.

[0236] The WTRU may be configured to provide TEG information to the network. For example, in a WTRU-based positioning method, the WTRU may provide location information and / or information regarding the association of TEGs with PRS resource IDs. The WTRU may provide the TEG information based on one or more of the following triggers: an error variation associated with the WTRU position is greater than a threshold (e.g., configurable by the network, such as the LMF), or the variation of positioning measurements is greater than a threshold (e.g., configurable by the network, such as the LMF). This may allow the WTRU to indicate to the network (e.g., the LMF) that received data may contain timing errors at the WTRU side. The WTRU may indicate information regarding the association between the Rx TEG and PRS resource IDs to the network (e.g., the LMF).

[0237] The WTRU may be configured to report TEG information applicable to multiple positioning methods. The WTRU may determine whether a TEG is applicable to multiple positioning methods and may indicate to the network whether the TEG is applicable to one or more other TEGs used in different positioning methods. The WTRU may report an Rx TEG associated with PRS resources used in two or more positioning methods. In an example, the Rx TEG may be associated with measurements (e.g., RSTD, Rx-Tx time difference, etc.) used with the PRS resources, and the WTRU may indicate to the network that the same Rx TEG can be used for TDOA or multi-RTT, which require RSTD or Rx-Tx time difference, respectively. For example, in the case of a Tx TEG used for UL TDOA and multi-RTT, e.g., that may be used for UL-PRS transmission, the WTRU may indicate to the network that the same Tx TEG can be applied to both multi-RTT and UL TDOA.

[0238] The WTRU may report TEG information to the network (e.g., to the LMF), for example, in a measurement report. The WTRU may report information in association with one or more positioning methods (e.g., DL-based positioning methods). The WTRU may report one or more of the TEGs associated with PRS resources (e.g., each PRS resource, such as a DL-PRS resource, an UL-PRS resource, etc.) or a combined TEG of resources involved in measuring the positioning parameters. In an example (e.g., for a DL-based positioning method), the WTRU may report TEG information in association with an RSTD report. In an example, the WTRU may measure RSTD using at least two DL-PRS resources. In an example, if the WTRU uses multiple TEGs to receive DL-PRS resources involved in RSTD measurement, the WTRU may report which TEG is used for DL-PRS reception (e.g., each DL-PRS reception). In an example (eg, where a WTRU uses one TEG to receive two DL-PRS), the WTRU may report the TEG associated with both DL-PRS resources.

[0239] The WTRU may determine, for example, to use the same TEG for reception if the TEG is used to measure one positioning parameter (e.g., RSTD) for reporting. In an example, the WTRU may be indicated (e.g., by the network) to use the same TEG for DL-PRS reception and / or UL-PRS transmission. In an example, the WTRU may use the same TEG for DL-PRS reception in two or more DL-PRS resources for RSTD measurement. In an example, the WTRU may use the same beam, antenna port, and / or panel for DL-PRS reception for the DL-PRS resources involved in the RSTD measurement. The WTRU may report the TEG associated with the two or more DL-PRS resources to the network.

[0240] The WTRU may provide TEG information associated with measurements used in UL and DL-based positioning methods (e.g., WTRU Rx-Tx time difference measurements). The WTRU may provide a combined TEG (e.g., Rx-Tx TEG) associated with a pair of DL-PRS reception and UL-PRS transmission. The combined TEG (e.g., Rx-Tx TEG) may be determined as a function of the Tx TEG and / or the Rx TEG. The WTRU may include an SRSp resource ID (e.g., an SRSp resource ID used to determine the Tx timing of the WTRU Rx-Tx time difference measurement) when the WTRU reports the WTRU Rx-Tx time difference measurement to the network. The WTRU may indicate the Tx TEG ID associated with the SRSp resource used to determine the Tx timing of the WTRU Rx-Tx time difference measurement in the measurement report (e.g., or in a separate indication or report sent to the network, such as the LMF or gNB).

[0241] The WTRU may determine which TEG information to provide based on the capabilities of the WTRU. For example, the WTRU may have one or more of the following capabilities: (1) the ability to associate DL PRS resources or Rx receive timing with the Rx TEG; (2) the ability to associate UL positioning reference signal (e.g., SRSp) resources or Tx transmit timing with the Tx TEG; the ability to associate DL PRS resources or Rx receive timing with the Rx TEG and to associate UL positioning reference signal resources or Tx transmit timing with the Tx TEG; or (4) the ability to associate UL positioning reference signal resources and / or DL ​​PRS resources with the Rx / Tx TEG, or to associate Tx transmit timing and / or Rx receive timing with the Rx / Tx TEG. The WTRU may be configured (e.g., pre-configured) to report TEG information associated with the Rx-Tx timing difference. The WTRU may be configured (e.g., pre-configured) with an order for reporting TEG information based on the capabilities of the WTRU. For example, the WTRU may be configured (e.g., pre-configured) to report the information described under (4), (3), (2), or (1) above in a particular order based on the WTRU's capabilities. For example, the WTRU may determine that if the WTRU is capable of reporting the information described under (4), it will report it. Otherwise (e.g., if the WTRU is not capable of reporting (4)), the WTRU may report the information described under (3). If the WTRU is not capable of reporting (3) or (4), the WTRU may report the information described under (1) or (2) if it is capable of doing so. If the WTRU is not capable of reporting any of the TEG information described herein, the WTRU may indicate (e.g., to the network) that it is unable to report TEG information associated with the Rx-Tx timing difference.

[0242] The WTRU may determine to report multiple TEG information associated with the Rx-Tx timing difference. In an example, the WTRU may report the information described under (4) and (3) above. The WTRU may report the information described under (4) and (1) (or (4) and (2)) above. The WTRU may determine which TEG information to report based on the QoS requirements of the positioning service. The QoS requirements may include, for example, positioning accuracy requirements, periodicity of measurement reports, and / or latency of positioning measurements requirements.

[0243] Positioning in a wireless system may be implemented, for example, in the behavior of a WTRU during a base station (e.g., gNB) scan of a channel. The WTRU may be configured (e.g., by higher layers, e.g., higher layer signaling) to report line of sight (LOS). The WTRU may report timing information of a configured downlink (DL) reference signal (RS) for positioning to the network, which may correspond to the highest reference signal received power (RSRP) among multiple configured positioning reference signal (PRS) beams. LOS reporting may be performed, for example, when multiple beams are configured. The network may perform (e.g., implement) beam sweeping, for example, to find LOS and NLOS.

[0244] The WTRU can make recommendations to associate paths with channel and / or beam information. The WTRU can send measurement reports to the network. The measurement reports may include association of additional path identifiers (IDs) for the measured multipaths (e.g., measured multipath transmissions) with at least one of a Channel State Information Reference Signal (CSI-RS), PRS, or Sounding Reference Signal (SRS) beam. The associated RS beam may be different from the RS beam received by the WTRU that led to the discovery of the multipath, for example. The WTRU-based recommendation of multipath mitigation may consider different beamwidths and / or different granularity of transmission periods / offsets for the UL and DL RS.

[0245] There may be DL and UL cooperation. The DL and UL positioning methods may be configured by the network. The WTRU may transmit multiple configured SRS beams for positioning. The WTRU may anticipate and receive (e.g., be configured to) dynamic configuration of SRS spatial relationships for the positioning SRS (SRSp) and PRS, and / or receive an indication of in which direction the transmitted SRS was used (e.g., DL-UL cooperation, no reporting, and / or beam sweeping).

[0246] The assistance information for the positioning corrections may be generated (e.g., outside the LMF, e.g., in a function). The WTRU may obtain the assistance information, e.g., on an on-demand basis, and / or the WTRU may be configured (e.g., by a server) to receive standalone assistance information. The assistance information for the corrections may be delivered to the function by the WTRU or delivered from the function to the WTRU (e.g., for WTRU-based positioning). In an example, the assistance information may include multipath channel parameters (e.g., relative power offsets, delay profiles, etc.).

[0247] The WTRU may transmit the panel ID to the network, for example, to assist the network in determining the orientation angle of the WTRU. The WTRU may receive (e.g., periodically) assistance information including a timing offset that the WTRU may apply to timing-related measurements.

[0248] The WTRU may use a first positioning method (e.g., based on multiple round-trip times (multi-RTT) with a single SRSp resource for reporting receive-transmit (Rx-Tx) time differences). The WTRU may switch (e.g., autonomously switch) to a second positioning method (e.g., based on multi-RTT with N SRSp resources, including a reference SRSp resource, for reporting Rx-Tx time differences), for example, based on a condition (e.g., detection of multiple paths in a fading channel). The WTRU may switch back to the first positioning method, for example, based on an exit condition being met (e.g., the WTRU no longer observes multiple paths in the channel).

[0249] The WTRU may receive one or more criteria from the network to use a single-path-based location estimate. The WTRU may determine to use measurements corresponding to a single path to derive a location estimate, for example, if a minimum number of measurements are available. The WTRU may report the location estimate to the network and may indicate (e.g., to the LMF) that single-path measurements will be used to derive the location estimate. The WTRU may switch to a multi-path-based derivation of the location estimate, for example, if a condition is not satisfied. The WTRU may receive one or more criteria related to a multi-path-based location estimate from the network. The WTRU may determine to calculate a location estimate based on the one or more criteria and may report the location estimate to the network (e.g., to the LMF).

[0250] The WTRU may observe multiple paths, e.g., through RSRP measurements at a resolution and / or granularity that may be finer than the default resolution and / or granularity used by the WTRU for RSRP measurements and / or reporting. The default resolution and / or granularity for RSRP may be, e.g., no granularity, which may indicate that the WTRU averages the RSRP over resource elements (e.g., all resource elements) within the bandwidth allocated to the WTRU. The WTRU may determine the number of Rx beams to be used for Rx beam sweeping. The WTRU may perform Rx beam sweeping using the determined number of Rx beams and may report RSRP for each Rx beam for the PRS resource (e.g., at a resolution and / or granularity that may be finer than that typically used for RSRP reporting). The WTRU may indicate to the network that beam sweeping has been performed (e.g., implemented) and that the WTRU's orientation has not changed.

[0251] The WTRU may indicate to the network whether a timing error group (TEG) is applicable to multiple TEGs used in different positioning methods. The WTRU may determine the first path RSRP based on the arrival times of reference signals observed during a first time window and / or the accumulated or averaged RSRP determined over a second time window.

[0252] Although the above-described features and elements are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments, or may be used in various combinations with or without the other features and elements.

[0253] While implementations described herein may consider 3GPP-specific protocols, it is understood that the implementations described herein are not limited to this scenario and may be applicable to other wireless systems. For example, while the solutions described herein consider LTE, LTE-A, new radio (NR), or 5G-specific protocols, it is understood that the solutions described herein are not limited to this scenario and are also applicable to other wireless systems. For example, while systems have been described with reference to 3GPP, 5G, and / or NR network layers, contemplated embodiments extend beyond implementations using specific network layer technologies. Similarly, potential implementations extend to all types of service layer architectures, systems, and embodiments. The techniques described herein may be applied independently and / or used in combination with other resource configuration techniques.

[0254] The processes described herein may be implemented in a computer program, software, and / or firmware embodied in a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted via wired and / 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, but not limited to, internal hard disks and removable disks, magneto-optical media, and / or optical media such as compact disc (CD)-ROM disks and / or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, terminal, base station, RNC, and / or any host computer.

[0255] It is understood that the entities performing the processes described herein may be logical entities that may be implemented in the form of software (e.g., computer-executable instructions) stored in the memory of a mobile device, network node, or computer system and executed on a processor thereof. That is, the processes may be implemented in the form of software (e.g., computer-executable instructions) stored in the memory of a mobile device and / or network node, such as a node or computer system, which computer-executable instructions, when executed by a processor of the node, perform the discussed process. It is also understood that any transmit and receive processes shown in the figures may be performed by the node's communication circuitry under control of the node's processor and the computer-executable instructions (e.g., software) it executes.

[0256] The various techniques described herein may be implemented in connection with hardware or software, or a combination of both, where appropriate. Accordingly, implementations and apparatuses of the subject matter described herein, or certain aspects or portions thereof, may take the form of program code (e.g., instructions) embodied in tangible media, including any other machine-readable storage medium, which, when loaded and executed by a machine, such as a computer, causes the machine to become an apparatus for practicing the subject matter described herein. When program code is stored on a medium, the program code may be stored on one or more media that collectively perform the actions; i.e., one or more media together include code for performing the actions; however, when two or more single media are present, specific portions of code need not be stored on a specific medium. In the case of program code execution on a programmable device, the computing device generally includes a processor, a storage medium readable by the processor (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device. One or more programs may implement or utilize the processes described in connection with the subject matter described herein, for example, through the use of APIs, reusable controls, etc. Such programs are preferably implemented in a high level procedural or object-oriented programming language to communicate with a computer system, although the programs can be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language, and combined with hardware implementations.

[0257] Although example embodiments may refer to utilizing aspects of the subject matter described herein in the context of one or more standalone computing systems, the subject matter described herein is not so limited and may rather be implemented in connection with any computing environment, such as a network or distributed computing environment. Furthermore, aspects of the subject matter described herein may be implemented within or across multiple processing chips or devices, and storage may be affected similarly across multiple devices. Such devices may include personal computers, network servers, handheld devices, supercomputers, or computers integrated into other systems such as automobiles or airplanes.

[0258] In describing preferred embodiments of the subject matter of the present disclosure, as illustrated in the Figures, specific terminology is used for clarity, however, it is understood that the claimed subject matter is not intended to be limited to the specific terminology so selected, and that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.

Claims

1. 1. A wireless transmit / receive unit (WTRU), comprising: a processor, the processor comprising: receiving a positioning reference signal (PRS) transmission over a plurality of paths; associating a first path with a first positioning sounding reference signal (SRSp), wherein the first path is associated with the first SRSp based on one or more of a first path direction or first SRSp spatial relationship information associated with the first path direction, and the first SRSp spatial relationship information is received from a network entity; associating a second path with a second SRSp, wherein the second path is associated with the second SRSp based on one or more of a second path direction or second SRSp spatial relationship information associated with the second path direction, and the second SRSp spatial relationship information is received from the network entity; transmitting information indicative of the association to the network entity; transmitting a first SRSp over a first SRSp resource and a second SRSp over a second SRSp resource; determining a first receive-transmit (Rx-Tx) time difference associated with the first path, the first Rx-Tx time difference being a time difference from when the PRS transmission was received over the first path to when the first SRSp was transmitted; determining a second Rx-Tx time difference associated with the second path, the second Rx-Tx time difference being a time difference from when the PRS transmission was received over the second path to when the second SRSp was transmitted; and transmitting information indicative of the first and second Rx-Tx time differences to the network entity.

2. The processor: receiving the first SRSp spatial relationship information and the second SRSp spatial relationship information from the network entity; assigning a first path identifier (ID) to the first path and a second path ID to the second path; associating the first path ID with a first SRSp ID, wherein the first path ID is associated with the first SRSp ID based on the first path direction and the first SRSp spatial relationship information associated with the first path direction; 2. The WTRU of claim 1, further configured to: associate the second path ID with a second SRSp ID, wherein the second path ID is associated with the second SRSp ID based on the second path direction and the second SRSp spatial relationship information associated with the second path direction.

3. 3. The WTRU of claim 2, wherein the information indicating the first and second Rx-Tx time differences further includes the first path ID associated with the first SRSp ID and the second path ID associated with the second SRSp ID.

4. 2. The WTRU of claim 1, wherein the network entity is a location management function (LMF) or a base station (gNB).

5. the processor: The WTRU of claim 1 , further configured to receive, from the network entity, information indicating association of respective paths with respective SRSps.

6. 2. The WTRU of claim 1, wherein the first path is associated with the first SRSp based on the first path direction being consistent with the first SRSp spatial relationship information associated with the first path direction, and the second path is associated with the second SRSp based on the second path direction being consistent with the second SRSp spatial relationship information associated with the second path direction.

7. 1. A method comprising: receiving a positioning reference signal (PRS) transmission over a plurality of paths; associating a first path with a first positioning sounding reference signal (SRSp), wherein the first path is associated with the first SRSp based on one or more of a first path direction or first SRSp spatial relationship information associated with the first path direction, and the first SRSp spatial relationship information is received from a network entity; associating a second path with a second SRSp, wherein the second path is associated with the second SRSp based on one or more of a second path direction or second SRSp spatial relationship information associated with the second path direction, and the second SRSp spatial relationship information is received from the network entity; transmitting information indicative of the association to the network entity; transmitting a first SRSp over a first SRSp resource and a second SRSp over a second SRSp resource; determining a first receive-transmit (Rx-Tx) time difference associated with the first path, the first Rx-Tx time difference being a time difference from when the PRS transmission was received over the first path to when the first SRSp was transmitted; determining a second Rx-Tx time difference associated with the second path, the second Rx-Tx time difference being a time difference from when the PRS transmission was received over the second path to when the second SRSp was transmitted; transmitting information indicative of the first and second Rx-Tx time differences to the network entity.

8. receiving the first SRSp spatial relationship information and the second SRSp spatial relationship information from the network entity; assigning a first path identifier (ID) to the first path and a second path ID to the second path; associating the first path ID with a first SRSp ID, wherein the first path ID is associated with the first SRSp ID based on the first path direction and the first SRSp spatial relationship information associated with the first path direction; associating the second path ID with a second SRSp ID, wherein the second path ID is associated with the second SRSp ID based on the second path direction and the second SRSp spatial relationship information associated with the second path direction; The method of claim 7 further comprising:

9. 9. The method of claim 8, wherein the information indicating the first and second Rx-Tx time differences further includes the first path ID associated with the first SRSp ID and the second path ID associated with the second SRSp ID.

10. The method of claim 7, wherein the network entity is a location management function (LMF) or a base station (gNB).

11. receiving information from the network entity indicating association of each path with a respective SRSp; The method of claim 7 further comprising:

12. 8. The method of claim 7, wherein the first path is associated with the first SRSp based on the first path direction being consistent with the first SRSp spatial relationship information associated with the first path direction, and the second path is associated with the second SRSp based on the second path direction being consistent with the second SRSp spatial relationship information associated with the second path direction.

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