Support for low-power high-accuracy positioning

Abstract

Systems, methods, and instrumentalities are described herein for supporting low power high accuracy positioning (LPHAP). A wireless transmit / receive unit (WTRU) may receive configuration information from a first cell (e.g., in a radio resource control (RRC) reconfiguration message). The configuration information may indicate a first sounding reference (SRSp) configuration for positioning and a second SRSp configuration. The first SRSp configuration may be associated with a first positioning area, and the second SRSp configuration may be associated with a second positioning area. The first positioning area may include a first set of cell IDs, and the second positioning area may include a second set of cell IDs. The first SRSp configuration may be activated and the second SRSp configuration may be deactivated.

Description

[0001] This application is a divisional application of the Chinese invention patent application with application date of February 9, 2023 and application number 202380025388.8.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 410,967 filed on September 28, 2022, U.S. Provisional Patent Application No. 63 / 395,233 filed on August 4, 2022, U.S. Provisional Patent Application No. 63 / 335,341 filed on April 27, 2022, and U.S. Provisional Patent Application No. 63 / 308,405 filed on February 9, 2022, the disclosures of which are incorporated herein by reference in their entirety. Background Art

[0004] 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). Previous generation (legacy) mobile communications RAT may be, for example, fourth generation (4G) Long Term Evolution (LTE). Summary of the invention

[0005] Systems, methods, and instrumentalities that may be associated with supporting low power high accuracy positioning (LPHAP) are described herein.

[0006] A wireless transmit / receive unit (WTRU) may receive configuration information (e.g., in a radio resource control (RRC) reconfiguration message) from a first cell. The configuration information may indicate a first sounding reference for positioning (SRSp) configuration and a second SRSp configuration. The first SRSp configuration may be associated with a first positioning area, and the second SRSp configuration may be associated with a second positioning area. The first positioning area may include a first set of cell IDs, and the second positioning area may include a second set of cell IDs. The first SRSp configuration may be activated, and the second SRSp configuration may be deactivated.

[0007] The WTRU may send a first SRSp using the first SRSp configuration. In an example, the WTRU may send the first SRSp based on detecting a cell ID in the first cell ID set. The first SRSp may be sent during low power operation (e.g., INACTIVE operation / state or idle operation / state) (e.g., based on receiving a RRCRelease message). The WTRU may select (e.g., detect) a second cell. In an example, the WTRU may select (e.g., detect) the second cell based on the WTRU detecting a cell ID of the second cell.

[0008] The WTRU may determine that the second cell is in the second positioning area. In an example, the WTRU may determine that the second cell is located in the second positioning area based on the detected second cell ID being in the second cell ID set associated with the second positioning area. Based on the determination that the second cell is in the second positioning area, the WTRU sends a request to the second cell to activate the second SRSp configuration.

[0009] The WTRU may receive (e.g., from a second cell) an indication regarding activation of a requested second SRSp configuration or an indication regarding activation of a third SRSp configuration. The indication regarding activation may be received in a message from the second cell (e.g., in an RRC Resume message, an RRC Reconfiguration message, or a MAC Control Element (MAC CE)). The WTRU may send an indication regarding deactivation of the first SRSp configuration (e.g., when sending the request to activate the second SRSp configuration or in another indication request). The WTRU may send a second SRSp using the SRSp configuration indicated by the second cell (e.g., the requested second SRSp configuration or the third SRSp configuration). BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented.

[0011] Figure 1B is an example of a method that can be used according to one embodiment. Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within the illustrated communication system.

[0012] Figure 1C is an example of a method that can be used according to one embodiment. Figure 1A System diagram of an example Radio Access Network (RAN) and an example Core Network (CN) for use within the illustrated communication system.

[0013] Figure 1D is an example of a method that can be used according to one embodiment. Figure 1A System diagram of yet another example RAN and yet another example CN for use within the illustrated communication system.

[0014] Figure 2 It is illustrated that a WTRU in the INACTIVE state selects a location area specific SRSp configuration for performing SRSp transmission. DETAILED DESCRIPTION

[0015] Figure 1A1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The 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 multi-carrier (FBMC), etc.

[0016] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110 and other networks 112, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to send and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0017] The communication 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 that is configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0018] 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 the base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies (which may be referred to as cells (not shown)). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of licensed and unlicensed spectrums. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, a cell associated with the base station 114a may be divided into three sectors. Therefore, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to send and / or receive signals in a desired spatial direction.

[0019] 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).

[0020] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 115 / 116 / 117. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​UL Packet Access (HSUPA).

[0021] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-APro).

[0022] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using New Radio (NR).

[0023] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may together implement LTE radio access and NR radio access, for example using the dual connectivity (DC) principle. Thus, the air interface used 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).

[0024] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0025] Figure 1A The base station 114b in the 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 business location, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.11) to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.15) to establish a wireless personal area network (WPAN). In another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a micro-micro cell base station or a femto cell base station. As Figure 1A As shown, base station 114b may have a direct connection to Internet 110. Therefore, base station 114b may not need to access Internet 110 via CN 106 / 115.

[0026] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different 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 described in detail in the text and video, the CN 106 / 115 may be configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different 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. Figure 1AAlthough not shown in the figure, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0027] 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 circuit-switched telephone network that provides 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), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0028] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication 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 via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0029] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, 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 appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0030] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors 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 decoding, 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. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0031] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from the base station via an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, an IR, UV or visible light signal. In another embodiment, the send / receive element 122 may be configured to send and / or receive both an RF signal and an optical signal. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0032] Although the transmit / receive element 122 Figure 1B 1 as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0033] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0034] The processor 118 of the WTRU 102 may be coupled to 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) and may receive user input data therefrom. The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0035] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0036] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information 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 received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0037] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules 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 video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, etc. The peripheral device 138 may include one or more sensors, which may be one or more of the following: 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.

[0038] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via hardware (e.g., a choke) or via signal processing performed by a processor (e.g., a separate processor (not shown) or via the processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for uplink (UL) (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0039] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0040] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0041] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, etc. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0042] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements is depicted as being part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0043] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, 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.

[0044] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-evolved Node-B handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0045] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0046] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts 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 networks and / or wireless networks owned and / or operated by other service providers.

[0047] Although the WTRU Figures 1A to 1D Although described as wireless terminals, it is contemplated that in certain representative embodiments, such terminals may (eg, temporarily or permanently) use a wired communications interface with a communications network.

[0048] In a representative embodiment, the other network 112 may be a WLAN.

[0049] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STA) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or carries traffic away from the BSS. Traffic originating from outside the BSS and leading to the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA and leading to a destination outside the BSS may be transmitted to the AP to be delivered to the corresponding destination. Traffic between STAs within the BSS may be transmitted by the AP, for example, wherein the source STA may send traffic to the AP, and the AP may deliver traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Direct link establishment (DLS) may be utilized to transmit point-to-point traffic between the source STA and the destination STA (e.g., directly between them). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad-hoc" communication mode.

[0050] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may send 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 dynamically set via signaling. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may listen to the primary channel. When the primary channel is listened / 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.

[0051] High throughput (HT) STAs may communicate using a 40 MHz wide channel, for example, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0052] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and data can be sent by sending STA. At the receiver of the receiving STA, the above-mentioned operation for 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0053] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support instrument type control / machine type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0054] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (supporting only a 1MHz operating mode) is sending to the AP, the entire available frequency band may be considered busy even if most of the frequency bands remain idle and may be available.

[0055] In the United States, the available frequency band for 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. Depending on the country code, the total bandwidth available for 802.11ah is 6MHz to 26MHz.

[0056] Figure 1D 1 is a system diagram illustrating the RAN 113 and the CN 115 in accordance with an embodiment. As noted above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0057] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 108b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, gNB 180a may transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In an embodiment, gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0058] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with parameter sets that may be scalable. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmit time intervals (TTIs) of varying or scalable lengths (e.g., containing varying numbers of OFDM symbols and / or varying absolute time lengths over time).

[0059] 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 while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use 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 an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle 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 eNodeB 160a, 160b, 160c may act as a mobility anchor for the WTRUs 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0060] 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 UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b, routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0061] Figure 1DThe illustrated CN 115 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although each of the foregoing elements is depicted as part of the CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0062] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different PDU sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of NAS signaling, mobility management, etc. The AMF 182a, 182b may use network slicing to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 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 mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. 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.

[0063] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 115 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating WTRU 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.

[0064] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0065] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that 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 networks 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 via the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and the N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0066] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following may be performed by one or more simulation devices (not shown): WTRU102a-102d, base station 114a-114b, evolved Node B 160a-160c, MME 162, SGW 164, PGW 166, gNB 180a-180c, AMF 182a-182b, UPF 184a-184b, SMF 183a-183b, DN 185a-185b and / or any other device described herein. The simulation device may be one or more devices configured to mimic one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0067] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for testing purposes and / or may use over-the-air wireless communications to perform testing.

[0068] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via an RF circuit system (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0069] References to timers herein may refer to determination of a time or determination of a time period. References to expiration of a timer herein may refer to determination that a time has occurred or a time period has expired. References to timers herein may refer to a time, a time period, tracking a time, tracking a time period, etc. References to expiration of a timer herein may refer to determination that a time has occurred or a time period has expired.

[0070] Systems, methods, and instrumentalities that may be associated with supporting low power high accuracy positioning (LPHAP) are described herein.

[0071] The WTRU may receive configuration information from a first cell (e.g., in a radio resource control (RRC) reconfiguration message). The configuration information may indicate a first sounding reference signal for positioning (SRSp) configuration and a second SRSp configuration. The first SRSp configuration may be associated with a first positioning area, and the second SRSp configuration may be associated with a second positioning area. The first positioning area may include a first set of cell IDs, and the second positioning area may include a second set of cell IDs. The first SRSp configuration may be activated, and the second SRSp configuration may be deactivated.

[0072] The WTRU may send a first SRSp using the first SRSp configuration. In an example, the WTRU may send the first SRSp based on detecting a cell ID in the first set of cell IDs. The first SRSp may be sent during low power operation (e.g., INACTIVE operation / state or idle operation / state) (e.g., based on receiving a RRCRelease message). The WTRU may select (e.g., detect) a second cell. In an example, the WTRU may select (e.g., detect) the second cell based on the WTRU detecting a cell ID of the second cell.

[0073] The WTRU may determine that the second cell is in the second positioning area. In an example, the WTRU may determine that the second cell is located in the second positioning area based on the detected second cell ID being in the second cell ID set associated with the second positioning area. Based on the determination that the second cell is in the second positioning area, the WTRU sends a request to the second cell to activate the second SRSp configuration.

[0074] The WTRU may receive (e.g., from a second cell) an indication regarding activation of a requested second SRSp configuration or an indication regarding activation of a third SRSp configuration. The indication regarding activation may be received in a message from the second cell (e.g., in an RRC Resume message, an RRC Reconfiguration message, or a MAC Control Element (MAC CE)). The WTRU may send an indication regarding deactivation of the first SRSp configuration (e.g., when sending the request to activate the second SRSp configuration or in another indication request). The WTRU may send a second SRSp using the SRSp configuration indicated by the second cell (e.g., the requested second SRSp configuration or the third SRSp configuration).

[0075] The WTRU may perform LPHAP by operating in a measurement mode and / or an estimation mode. The WTRU may operate in a positioning estimation mode. The WTRU may transmit capabilities or assistance information for estimation mode operation. The WTRU may receive assistance data for LPHAP operation. The WTRU may switch between different positioning modes based on switching criteria. The WTRU may perform LPHAP if triggered by a paging message. The WTRU may transmit information about LPHAP operation to the network.

[0076] Examples are provided herein for supporting downlink (DL) based LPHAP. When LPHAP is supported, the WTRU may utilize DL based positioning to mitigate positioning errors. The WTRU may perform LPHAP based on location related configuration or resources. The WTRU may use DL based positioning configuration information based on telecommunication relay service (TRS) reception. The WTRU may perform prediction of the WTRU position to compensate for reduced DL measurements.

[0077] Examples are provided herein for supporting uplink (UL) based LPHAP. The WTRU may perform uplink sounding reference signal (UL-SRSp) transmission for positioning for LPHAP based on a UL configured positioning area. The WTRU may perform UL based LPHAP based on location related configuration or resources. The WTRU may use common SRSp resources based on sensing. Based on the detection of a triggering event, the WTRU may change or switch between SRSp configurations for supporting UL based LPHAP. The WTRU may send an SRSp based on the detection of a location in a preconfigured positioning area. The WTRU may send an SRSp based on the detection of a time opportunity for a transmit (Tx) schedule and a triggering event.

[0078] Examples of supporting positioning using mobile terminated small data transmission (MT-SDT) are provided herein. A WTRU may be configured with MT-SDT to support positioning in low power operation (e.g., INACTIVE / IDLE state / operation / mode). For example, when operating in radio resource control (RRC) INACTIVE / IDLE mode, the WTRU may receive indications / information about positioning via MT-SDT. WTRU behaviors / actions associated with location may be based on whether MT-SDT is configured or initiated. The WTRU may determine and transmit to the network an indication of the attributes of the expected DL positioning information based on the configured MT-SDT. The WTRU may receive positioning information in a DL transmission based on a data volume threshold configured for the MT-SDT. The WTRU may transmit indications / information about the RRC state and / or MO-SDT / MT-SDT configuration to a location management function (LMF) to support associated positioning procedures. The WTRU may receive indications configured using MT-SDT during mobility. The WTRU may receive auxiliary data or configuration for positioning via MT-SDT during mobility. The WTRU may be configured with a periodic positioning reference signal (PRS) / SRSp. The periodic PRS / SRSp may be associated with the periodicity of a discontinuous reception (DRX) cycle. The WTRU may determine a mode for reporting measurements in the INACTIVE / IDLE state.

[0079] Examples are provided herein for supporting DL and UL based LPHAP. When in low power operation (e.g., INACTIVE / IDLE state / operation / mode), the WTRU may be configured to perform DL and UL positioning based on trigger events. When operating in the INACTIVE state, the WTRU may transmit positioning information to the network. When operating in the INACTIVE state, the WTRU may transmit indications to the network to assist in the prediction of the WTRU's location. The WTRU may select a positioning area specific SRSp configuration based on the positioning area in which the WTRU is located. The WTRU may transmit a request to update the validity condition of the SRSp configuration. The WTRU may select an SRSp configuration based on a detectable TRP. The WTRU may select an SRSp configuration based on the expected measurement accuracy in the positioning area in which the WTRU is located.

[0080] In a low power high accuracy positioning (LPHAP) use case (e.g., industrial, utility, asset tracking), the location of the WTRU may be tracked while operating in low power operation (e.g., INACTIVE state / operation / mode and / or IDLE state / operation / state) for an extended duration (e.g., 6 months to 1 year without charging / changing the battery). Minimizing the signaling overhead and frequency of reporting positioning information / measurements to the network or network equipment may be desirable (e.g., for power conservation). When tracking the location of the WTRU, high positioning accuracy (e.g., with <1m horizontal accuracy) may be achieved. For example, high positioning accuracy may be achieved by minimizing the frequency and signaling overhead of reporting positioning information / measurements to the network and by estimating the WTRU location information using interpolation techniques. Interpolating the WTRU location information between reports (e.g., the WTRU may transmit reports less frequently by including predictions) may exploit the survival concept of LPHAP, where a location services (LCS) client / application may tolerate lost or no positioning reports or information. In LPHAP, the location of the WTRU relative to an expected trajectory may be determined. For example, this may be desirable if the WTRU is mobile (eg, attached to an asset, a robot, etc.).

[0081] The examples provided herein support positioning during low power operation (eg, INACTIVE / IDLE state / mode / operation) and during WTRU mobility, which may result in a trade-off between achieving high accuracy and high power savings.

[0082] A WTRU may be preconfigured with a sounding reference signal (SRSp) / positioning reference signal (PRS) configuration for positioning to use during an INACTIVE / IDLE state based on knowledge of the trajectory that the WTRU is expected to use (e.g., on a factory floor). For UL-based positioning, the preconfigured SRSp may include a default SRSp configuration (e.g., low bandwidth (BW)) and / or a high accuracy SRSp configuration (e.g., high BW). For example, the WTRU may select an SRSp configuration if and / or when triggered by one or more events. The one or more triggering events may include one or more of time (e.g., scheduled time occasion), positioning area (e.g., cell / TRP list), radio conditions, or positioning QoS (e.g., whether the expected level of accuracy is achieved). Power savings in the WTRU may be achieved by minimizing the timing, duration, and bandwidth for sending one or more SRSp (UL-based) and / or for performing PRS measurements / reporting (DL-based). Power savings may (e.g., may also) be achieved by not sending one or more SRSp / measuring PRS (e.g., in the event that the accuracy requirement cannot be met) and using prediction / interpolation techniques.

[0083] Examples of SRSp transmission based on scheduled Tx opportunities are provided herein. For scheduled SRSp transmission, the WTRU may be configured with one or more scheduled Tx opportunities for transmitting SRSp and SRSp configurations associated with the Tx opportunities. The WTRU may select a first SRSp configuration (e.g., a high periodicity configuration) for SRSp transmission that produces high accuracy during the initial phase of positioning (e.g., when starting to move from a stationary position) or when an event indicating low accuracy is detected. When the accuracy requirement is met and / or remains stable, the WTRU may (e.g., may then) select a second SRSp configuration (e.g., a low periodicity configuration) in a positioning phase (e.g., a subsequent positioning phase). When an interruption event is detected (e.g., a change in mobility state, a DL indication is received), the WTRU may reset the SRSp transmission process based on the type of event (e.g., this may help positioning accuracy and power saving).

[0084] The WTRU may receive configuration information. The configuration information may include one or more SRSp configurations. The SRSp configuration may include at least one or more resources in a first SRSp configuration (e.g., a high periodicity SRSp configuration) and / or a second SRSp configuration (e.g., a low periodicity SRSp configuration). The configuration information may include (e.g., may also include) one or more SRSp Tx opportunities (e.g., T0, T1, T2) for sending one or more SRSps. The Tx opportunity (Ti) may be associated with the SRSp configuration. During the initialization phase of positioning (e.g., at T0), the WTRU may start a timer that may run for a duration (e.g., a configured duration, T1 to T0). The WTRU may select an SRSp configuration associated with a current SRSp Tx opportunity (e.g., if the current SRSpTx opportunity is T0, the WTRU may select the first SRSp configuration (high periodicity), and if the current SRSp Tx opportunity>T0, the WTRU may select the second SRSp configuration (low periodicity)). The WTRU may transmit an indication to the network that may indicate the start of SRSp transmission (e.g., when the current Tx timing is T0). The WTRU may use resources in the selected SRSp configuration to transmit the SRSp. When an event (e.g., an interruption event) is detected (e.g., reception of DL data / indication, mobility state change), the WTRU may stop the timer and stop the transmission of the SRSp. When the event (e.g., the second event) is a semi-static event (e.g., reception of periodic data), the WTRU may restart the timer and restart the transmission of the SRSp using the current SRSp configuration (e.g., the SRSp configuration associated with the most recent Tx timing). When the event (e.g., the second event) is a dynamic event (e.g., reception of ultra-reliable and low-latency communication (URLLC) data, mobility state change), the WTRU may perform one or more of the following: reset the timer (e.g., reset to T0); transmit an indication to the NW indicating the reset and start of SRSp transmission, or send the SRSp using resources in the SRSp configuration associated with the SRSp Tx time timing (e.g., T0). When the event (e.g., the second event) corresponds to suspending transmission (e.g., receiving a DL indication to stop SRSp transmission), the WTRU may stop the timer and stop the transmission of SRSp. If no event (e.g., the second event) is detected, the WTRU may stop SRSp transmission when the timer expires, for a configured duration, or until the next Tx opportunity begins.

[0085] Examples of SRSp transmission based on configured positioning areas are provided herein. For area-dependent transmission, the WTRU may transmit SRSp at a preconfigured positioning area (e.g., the coverage area of ​​a set of TRPs) using an associated SRSp configuration. The WTRU may select a preconfigured SRSp configuration based on the trajectory that the WTRU is expected to follow and based on the expected accuracy of the measurements to be achieved at the corresponding TRP. If the expected accuracy requirement is not met at a TRP, the WTRU may use SRSp associated with some TRPs that may meet the accuracy (e.g., a special SRSp configuration with high BW).

[0086] The WTRU may receive configuration information. The configuration information may include one or more SRSp configurations, including at least resources in a low BWS SRSp configuration and a high BW SRSp configuration (e.g., a special SRSp configuration). The configuration information may (e.g., may also) include one or more TRP sets (e.g., cell IDs). One or more TRP sets may be associated with one or more SRSp configurations (e.g., each TRP set may be associated with an SRSp configuration) (e.g., the TRPs in the set may be configured by the LMF for SRSp measurements). The configuration information may (e.g., may also) include a threshold for the minimum number of TRPs required to meet accuracy requirements. The WTRU may perform SSB / TRS measurements to detect one or more transmit receive points (TRPs) and determine the radio conditions associated with the detected TRPs (e.g., using RSRP measurements of RSs spatially related to the SRSp). When the detected TRP matches the configured TRP set and / or when the number of detected TRPs with good reference signal received power (RSRP) is greater than a threshold of the minimum number of TRPs required to meet the accuracy requirement, the WTRU may select a low BW SRSp configuration associated with the detected TRP and may use resources in the low BW SRSp configuration to send the SRSp. When the detected TRP matches the configured TRP set and when the number of detected TRPs with good RSRP is less than a threshold, the WTRU may perform one or more of the following: determine a high BW SRSp configuration (e.g., a special SRSp configuration) associated with the detected TRP with good RSRP based on pre-configuration and / or received positioning system information block (SIB); transmit an indication to the gNB indicating the ID of the detected TRP (e.g., using RACH-SDT) and a request to activate the high BW SRSp configuration (e.g., special SRSp configuration); or send the SRSp using resources in the high BW SRSp configuration (e.g., special SRSp configuration) (e.g., after receiving an indication from the gNB). When the detected TRP does not match the configured TRP set, the WTRU may transmit an indication to the gNB to request an updated SRSp configuration, and may send the SRSp using resources in the updated SRSp configuration (e.g., after receiving the updated SRSp configuration from the gNB).

[0087] This article provides a downlink positioning example, an uplink positioning example, and a downlink and uplink positioning example.

[0088] In a downlink positioning example, the WTRU may receive one or more PRSs from one or more TRPs. The WTRU may observe multiple reference signals and may measure the arrival time difference between PRSs (e.g., a pair of PRSs). The WTRU may (e.g., may then) transmit the measured reference signal time difference (RSTD) to the LMF. The WTRU may (e.g., additionally) transmit the measured RSRP for the PRSs (e.g., the measured RSRP for each of the one or more PRSs). Based on the returned measurements, the LMF may perform positioning of the WTRU. The WTRU may report the RSRP for angle-based DL positioning.

[0089] The LMF is a non-limiting example of a node or entity (eg, a network node or entity) that may be used for or support positioning. In examples, other nodes (eg, any other node or entity) may replace the LMF.

[0090] In the uplink positioning example, the WTRU may transmit an SRS for positioning (e.g., configured by RRC) to a reception point (RP). For the timing-based method, the TRP may measure the RTOA of the received SRS and may report the measured value to the LMF. The TRP may report the RSRP of the SRS. In the angle-based uplink positioning method, the RP may measure the angle of arrival and may report it to the LMF.

[0091] In the uplink and downlink positioning examples, the WTRU may measure the Rx-Tx time difference between the received PRS and the transmitted SRS. The Rx-Tx time difference may be reported from the WTRU to the LMF. The WTRU may (e.g., may also) report the RSRP measured for the PRS. At the TRP, the Rx-Tx difference between the received SRS and the transmitted PRS may be calculated.

[0092] This article provides the following targeting examples.

[0093] "DL positioning example" may refer to any positioning example using downlink reference signals (such as PRS). The WTRU may receive one or more reference signals from the TP and may measure DL RSTD and / or RSRP. Examples of DL positioning are DL-AoD or DL-TDOA positioning.

[0094] "UL positioning example" may refer to any positioning example using uplink reference signals such as SRS for positioning. The WTRU may send SRS to multiple RPs, and these RPs may measure UL RToA and / or RSRP. Examples of UL positioning may include UL-TDOA or UL-AoA positioning.

[0095] “DL and UL positioning examples” may refer to positioning examples where uplink and downlink reference signals may be used for positioning. The WTRU may send an SRS to multiple TRPs and the gNB may measure the Rx-Tx time difference. The gNB may measure the RSRP of the received SRS. The WTRU may measure the Rx-Tx time difference of the PRS sent from multiple TRPs. The WTRU may measure the RSRP of the received PRS. The Rx-TX difference and / or RSRP measured at the WTRU and the gNB may be used to determine the round trip time. The Rx and Tx difference may refer to the difference between the arrival time of the reference signal sent by the TRP and the transmission time of the reference signal sent from the WTRU. An example of DL and UL positioning is multi-RTT positioning.

[0096] “Network” may include AMF, LMF, base station, TRP or gNB in ​​NG-RAN.

[0097] Positioning examples for DL-PRS measurements in RRC CONNECTED may allow intra-gNB mobility (e.g., a limited level of intra-gNB mobility) (e.g., within the coverage area of ​​a TRP belonging to the same gNB) and / or inter-gNB mobility (e.g., for scenarios where multiple gNBs use the same PRS configuration). Reporting of measurement or location information to the LMF may be supported via the serving gNB / cell.

[0098] Examples herein provide WTRU-based and LMF-based (e.g., WTRU-assisted) positioning for RAT-dependent and RAT-independent positioning. WTRU behaviors and examples (e.g., including examples related to configuration, transmission, measurement and reporting, low latency WTRU, high power savings, and high accuracy) for supporting low power high accuracy positioning (LPHAP) may be provided herein. Examples of using LPP to determine positioning information for a WTRU with LPHAP may be provided herein.

[0099] In a DL-based positioning example, the WTRU may perform measurements of resources associated with the DL-PRS. The WTRU may transmit measurement reports to the LMF based on assistance data provided by the network. In an UL-based positioning example, the WTRU may be configured with SRS (SRSp) resources for positioning via RRC signaling. The transmission of SRSp by the WTRU may (e.g., may then) be received by different TRPs / gNBs in the network for performing positioning measurements and reporting the measurements to the LMF that determines the WTRU's position. If the WTRU enters a different coverage area including a set of TRPs / gNBs (e.g., an updated / new TRP / gNB), the PRS / SRSp configuration (e.g., an updated / new PRS / SRSp configuration) may be provided to the WTRU. This may result in a waste of resources and power inefficiency because the positioning example (e.g., reception of configuration, transmission of SRSp, measurement of PRS) may be performed regardless of the WTRU's power saving mode, the WTRU's mobility attributes (e.g., stationary or slow moving), and / or the achievable positioning QoS (e.g., accuracy, latency).

[0100] Examples are provided herein that support positioning during low power operation (eg, INACTIVE / IDLE state / operation / mode operation) and during WTRU mobility, which results in a trade-off between achieving high accuracy and high power savings.

[0101] The sounding reference signal used for positioning may be denoted as "SRSp". The PRS or SRS used herein is not limited to RS used for positioning. The examples herein may be applied to or used with (e.g., any) DL or UL reference signal. It should be noted that "SRSp" herein refers to an SRS signal / transmission used for positioning. The resources of the SRS (SRSp) used for positioning may be defined (e.g., signaled) by RRC. SRS resource sets and SRS resources configured for positioning may be specified. The "SRS for positioning" or "SRS" in this article may include at least one of the following: an SRS that can be configured under SRS-PosResourceSet and SRS-PosResource; an SRS that can be configured under SRS-ResourceSet and SRS-Resource; an SRS that may not be configured under SRS-PosResourceSet and SRS-PosResource; an SRS that may not be configured under SRS-ResourceSet and SRS-Resource; an SRS that may not be associated with SRS-PosResourceSet, SRS-PosResource, SRS-ResourceSet or SRS-Resource; an associated uplink reference signal for positioning; a demodulation reference signal (DM-RS) for uplink; or a phase tracking reference signal (PTRS) for uplink.

[0102] This document provides positioning configuration examples. The positioning configuration may include information related to positioning measurements and / or SRSp transmission. One or more of the following information may be included in the positioning configuration: one or more positioning examples used (e.g., DL-TDOA, UL-TDOA, DL-AoD, UL-AoA, multi-RTT); PRS configuration; SRSp configuration; uplink resources used to report positioning measurements (e.g., physical downlink control channel (PRACH), physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH)); one or more thresholds for determining the quality of positioning measurements; positioning operation mode (e.g., the starting positioning operation mode). The PRS resource configuration may include at least one of the following: PRS resource ID; PRS sequence ID or other ID used to generate the PRS sequence; PRS resource element offset; PRS resource slot offset; PRS symbol offset; PRS QCL information; PRS resource set ID; a list of PRS resources in a resource set; number of PRS symbols; muting mode, muting parameters such as repetition factor, muting options for PRS; PRS resource power; periodicity of PRS transmission; spatial direction information of PRS transmission (e.g., beam information, transmission angle); spatial direction information of UL RS reception (e.g., beam ID, arrival angle for receiving UL RS); frequency layer ID; TRP ID; or PRS ID.

[0103] The SRSp resource configuration may include at least one of the following: resource ID; comb offset value, cyclic shift value; starting position in the frequency domain; number of SRSp symbols; shift in the frequency domain for SRSp; frequency hopping mode; type of SRSp (e.g., non-periodic, semi-persistent, or periodic); sequence ID for generating SRSp or other ID for generating SRSp sequence; spatial relationship information indicating which reference signal space the SRSp is related to; resource set ID; a list of SRSp resources in a resource set; transmit power related information; path loss reference information, which may include an index for SSB, CSI-RS, or PRS; periodicity of SRSp transmission; spatial direction information of SRSp transmission (e.g., beam information, transmit angle); or spatial direction information of DL RS reception (e.g., beam ID and / or arrival angle for receiving DL RS).

[0104] As part of the SRSp resource configuration, the WTRU may receive information related to a cell ID, a global cell ID, or a TRP ID. The received information may be associated with a PRS. The TRP that sends the PRS may be identified by the TRP ID. The TRP ID may belong to the cell identified by the cell ID. The WTRU may be configured with timing information, such as an SFN offset for PRS or SRSp transmission. The offset may prevent the WTRU from receiving overlapping PRSs in the time domain.

[0105] This article provides examples for supporting generic LPHAP.

[0106] The WTRU may perform LPHAP by operating in a measurement mode and / or an estimation mode. The WTRU may operate in a measurement mode and / or an estimation mode, possibly to meet positioning requirements associated with the LPHAP service (eg, low power, high positioning accuracy).

[0107] WTRU operation in measurement mode may refer to one or more of the following: DL-based positioning; UL-based positioning; DL+UL-based positioning; areas and / or time opportunities that may be associated with different reference locations and / or reference time instances at which the WTRU may perform measurements and / or send; or areas and / or time opportunities that the WTRU may receive from the network or application.

[0108] For DL-based positioning, measurements of DL signals (e.g., PRS, CSI-RS, SSB, TRS) may be performed to determine the location of the WTRU in one or more areas and / or at a time opportunity based on the measurements made by the WTRU. Examples of DL-based positioning may include DL-TDoA, DL-AoD, etc.

[0109] For UL-based positioning, transmission of UL signals (e.g., SRSp, SRS) may be performed to determine the location of the WTRU in one or more areas and / or at a time opportunity based on measurements made by the TRP / gNB. Examples of UL-based positioning may include UL-TDoA, UL-AoA, etc.

[0110] For DL+UL based positioning, a combination of DL based and UL based positioning (eg, a multi-RTT approach) may be performed to determine the location of the WTRU in different areas and / or at different time instances.

[0111] For the WTRU to receive the area and / or time opportunity from the network or application, the WTRU may receive the area and / or time opportunity from the network or application, for example, possibly as configuration / assistance information. The network may correspond to one or more of the following: one or more base stations (e.g., a serving gNB or a non-serving gNB in ​​an NG-RAN), a TRP, LMF, AMF, or LCS client associated with one or more base stations.

[0112] WTRU operation in estimation mode may refer to one or more of the following. WTRU operation in estimation mode may perform limited measurements of DL signals (e.g., DL-PRS, CSI-RS) or no measurements. WTRU operation in estimation mode may perform limited transmission of UL signals (e.g., SRSp, SRS) or no transmission. WTRU operation in estimation mode may refer to the WTRU / NW using prediction / extrapolation techniques to determine the position of the WTRU in future areas and / or time periods (e.g., p(T2)=p(T1)+v(T2-T1), where p is the position of the WTRU and v is the velocity of the WTRU). WTRU operation in estimation mode may refer to the WTRU / NW using smoothing / interpolation techniques to determine or correct the position of the WTRU in previous / past areas and / or time periods (e.g., p(T1)=p(T2)-v(T2-T1)). WTRU operation in estimation mode may refer to prediction and / or smoothing techniques used to estimate the position of the WTRU. WTRU operation in estimation mode may refer to the WTRU using internal sensors (e.g., accelerometer, gyroscope, magnetometer) to measure the WTRU speed, direction, orientation, and rate of movement. WTRU operation in estimation mode may refer to the WTRU performing sensor measurements periodically or when triggered by an event (e.g., measurement / estimation error above / below one or more thresholds in the case of operation in measurement mode). WTRU operation in estimation mode may refer to the WTRU supplementing limited PRS measurements and / or SRSp transmissions by performing sensor measurements to save power and / or improve positioning accuracy. WTRU operation in estimation mode may refer to the WTRU transmitting information of the WTRU position determined in estimation mode and / or by sensor measurements to the LMF based on a reporting configuration received from the LMF (e.g., for WTRU-assisted mode or WTRU-based mode).

[0113] Prediction and / or smoothing techniques that may be used to estimate the position of the WTRU may be based on using one or more of: RAT-related techniques (e.g., PRS measurements and / or SRSp transmissions), RAT-independent techniques (e.g., GNSS measurements or sensor measurements), information about the mobility state of the WTRU (e.g., stopped, moving at a first rate, moving at a second rate), or information about the WTRU's trajectory (e.g., expected WTRU positions at different time instances).

[0114] An example of a WTRU operating in a position estimation mode may be provided. The WTRU may operate in a measurement mode in a first time window / interval and in an estimation mode in a second time window. During the estimation mode, location information of the WTRU in at least the second time window may be determined by the WTRU and / or the network based on an expected change in the WTRU position relative to measurements taken during the first time window.

[0115] During the estimation mode, the WTRU may track the movement, mobility and / or trajectory attributes of the WTRU relative to a reference area and / or time occasion used to determine the location of the WTRU. The WTRU may perform measurements of DL-PRS or transmission of SRSp at an initial reference time. The WTRU may (e.g., may then) suspend performing measurements and / or transmissions during mobility while tracking and / or recording information related to movement / mobility attributes, such as speed, direction, distance and / or time elapsed since a previous reference time. The WTRU may perform DL-PRS measurements or UL-SRSp transmissions at a next reference time. The location of the WTRU at a time (e.g., any given time) may (e.g., may then) be determined or estimated by the WTRU or the network based on, for example, measurement information and / or tracking and / or recording information of mobility and / or trajectory attributes at one or more reference time instances.

[0116] Regarding operation in the estimation mode for estimating, predicting and / or smoothing the WTRU's position information, a WTRU-assisted estimation mode and / or a WTRU-based estimation mode may be applicable.

[0117] For the WTRU assisted estimation mode, the WTRU may transmit reports of measurements and / or mobility attributes (e.g., speed, direction) to the network periodically, aperiodically, or upon detection of an event trigger (e.g., possibly based on assistance data received from the network). When an event trigger is detected (e.g., a change in radio conditions, WTRU mobility state, trajectory, etc.), the WTRU may send UL-SRSp using periodic, aperiodic, or semi-persistent SRSp resource configurations. The position of the WTRU at different times may be estimated by the network by applying prediction, interpolation, and / or extrapolation techniques (e.g., to compensate for limited measurements or lack of a complete set of measurements). The WTRU may transmit information about PRS measurements, changes in trajectory attributes (e.g., changes in WTRU movement relative to an expected trajectory / position known to the network), error conditions, and / or prediction and / or smoothing information related to the WTRU position.

[0118] For WTRU-based estimation mode, the WTRU may receive assistance information from the network, the assistance information including one or more DL-PRS configurations and / or SRSp configurations, correction information for adjusting / compensating errors in measurements, or reference areas and / or times at which the WTRU may operate in measurement mode (e.g., performing DL-PRS measurements or UL-SRSp transmissions) or estimation mode (e.g., performing sensor measurements). The WTRU may switch between measurement mode and estimation mode periodically and / or upon detection of an event / condition (e.g., measured RSRP is above / below an RSRP threshold, mobility state of the WTRU changes). The WTRU may (e.g., may then) estimate the location of the WTRU at different time instances based on at least one of the assistance information, measurements, or sensor tracking information. When switching between measurement and estimation modes, the WTRU may transmit one or more indications to the network. The WTRU may (e.g., may also) transmit information regarding at least one of: the position of the WTRU determined via an estimation mode (e.g., during an estimation mode), an error in the estimate, a confidence level (e.g., in the estimated position), or an uncertainty in the determined WTRU position or measurements determined during an estimation mode. The WTRU may transmit predicted position information (e.g., the position of the WTRU in geographic coordinates or relative position) or smoothed position information (e.g., corrected position information made in the past) based on current measurements. The WTRU may associate a timestamp or a relative timestamp (e.g., a time difference between current timestamps expressed in milliseconds, symbols, slots, frames, or subframes) with the predicted or smoothed position information.

[0119] A WTRU may transmit capabilities and / or assistance information for estimation mode operation. In an example, upon detecting one or more triggering events (e.g., as described herein), the WTRU may transmit capabilities and / or assistance information to a network (e.g., a gNB or LMF) for operation in a positioning estimation mode. The WTRU may transmit capabilities and / or assistance information semi-statically before and / or after initializing a positioning procedure (e.g., an LPP session) for determining the WTRU's position, which may include, for example, operation in a measurement mode or an estimation mode (e.g., prediction). The WTRU may transmit capabilities / assistance information dynamically or on-demand at some time after the initialization of the positioning procedure. The WTRU may transmit capabilities / assistance information to the network in an LPP message (e.g., an LPP Provide Capability Information or an LPP Provide Assistance Information message) or in AS layer signaling / messages (e.g., using one or more of RRC, MAC CE, uplink control information (UCI), or PUSCH).

[0120] The information transmitted by the WTRU to the network, whether as capability information (e.g., via the LTE Positioning Protocol (LPP) capability transfer procedure, AS layer signaling / messages) or assistance information (e.g., via the LPP assisted data transfer procedure, AS layer signaling / messages), may include one or more of the following: examples applied when operating in estimation mode; device properties and / or parameters; achievable accuracy; reference locations, reference time instances and / or trajectories; or information about power saving modes.

[0121] Examples applied in the case of operating in estimation mode may include one or more of the following. When operating in estimation mode, the WTRU may indicate the ability to operate in a WTRU-assisted mode and / or a WTRU-based mode associated with the estimation mode. For example, when operating in WTRU-based mode, the WTRU may indicate the ability to estimate the position of the WTRU while performing limited PRS measurements and / or SRSp transmissions or no PRS measurements and / or SRSp transmissions. When operating in estimation mode, the WTRU may indicate sensor / device information. For example, the WTRU may indicate one or more identifiers and / or information associated with a sensor (e.g., a gyroscope, a magnetometer, an accelerometer, a GNSS receiver) that may be accessed by the WTRU for performing sensor measurements when operating in estimation mode. When operating in estimation mode, the WTRU may indicate technology / algorithm information. For example, the WTRU may utilize internal sensors / devices used to estimate the WTRU's position to indicate identifiers and / or information about the positioning algorithm used (e.g., dead reckoning). When operating in estimation mode, the WTRU may indicate prediction and / or smoothing information. For example, the WTRU may indicate an ID, information, configuration, and / or parameters related to prediction techniques and / or algorithms that are applied to predict the WTRU position based on limited or no measurements. Such techniques and parameters may include one or more of the following: the ability to use a neural network (NN), supported learning techniques (e.g., supervised learning, unsupervised learning, reinforcement learning), training data parameters, the (e.g., maximum) number of layers in the NN, the (e.g., maximum) number of neurons per layer, the (e.g., maximum) number of inputs / outputs / weights per neuron, or processing latency.

[0122] For device properties and / or parameters transmitted from the WTRU to the network, the WTRU may provide information about at least one of: the number of antenna elements / panels, the number of RF chains, antenna configuration information, supported bandwidth (e.g., per RF chain), or processing capabilities for transmission / reception, fused RF measurements, and / or sensor measurements (where estimation mode is supported).

[0123] For the achievable accuracy information transmitted from the WTRU to the network, the WTRU may provide one or more levels of positioning accuracy (e.g., per antenna element / panel, per Rx / Tx RF chain, per sensor / device) that are achievable when operating in estimation mode and / or measurement mode. The WTRU may indicate information about a timing error group (TEG), including, for example, a WTRU Tx TEG ID, a WTRU Rx TEG ID, a WTRU Rx-Tx TEG ID. For example, the WTRU may (e.g., may also) transmit association information between an SRSp resource and a WTRU Tx TEG ID. The WTRU may indicate whether it is possible to operate in measurement mode and estimation mode (e.g., simultaneously). The WTRU may indicate a confidence / weight / probability value (e.g., between 0 and 1) associated with operating in measurement mode and / or estimation mode. The confidence / weight / probability values ​​may (e.g., may also) be associated with different granularities including one or more of RAT-related / independent technology, positioning instance, PRS / SRSp configuration, frequency layer, resource set / resource, beam, or sensor measurement. The WTRU may (e.g., may also) indicate a priority value and / or preference value associated with the accuracy level.

[0124] For reference locations, reference time instances and / or trajectory information transmitted from the WTRU to the network, the WTRU may provide information (e.g., identifiers) regarding the availability and / or accessibility of one or more reference locations associated with a positioning reference unit (e.g., a WTRU, a TRP, a gNB, a cell, an NTN node, a satellite) or (e.g., any) detectable landmark (e.g., that may be near the WTRU). For example, the WTRU may (e.g., may also) provide a distance / range to the identified reference location. The WTRU may (e.g., may also) indicate information (e.g., IDs) regarding one or more positioning areas and / or zones (e.g., that may be associated with the coverage area of ​​one or more cells / TRPs / gNBs in which the WTRU was previously located, is currently located, and / or is expected to be located at different time instances).

[0125] For information about power saving modes communicated from the WTRU to the network, power saving modes supported by the WTRU and / or configured by the network may be provided (e.g., possibly including timing information (e.g., timestamps) for when the WTRU has previously transitioned to or is expected to transition to RRC CONNECTED, RRC INACTIVE, RRC IDLE, or any other combination of power saving modes / states). For example, the information about the power saving modes may include one or more configuration information or parameters associated with CDRX / DRX (e.g., cycle time on duration, inactivity timer duration). The WTRU may (e.g., may also) indicate priority values ​​and / or preference values ​​associated with supported power saving modes / states (e.g., possibly together with location / region information and / or timing information regarding where / when such priority / preference values ​​may apply).

[0126] The triggering events and / or conditions monitored by the WTRU for transmitting capability information and / or auxiliary information on the LPHAP may include one or more of the following: receiving an indication or LCS / LPP request from a higher layer / application / network; detecting a reference location and / or time; the periodicity of the triggering events and / or conditions; or a change in radio conditions or sensor measurements.

[0127] For receiving indications or LCS / LPP requests from higher layers / applications / network, the WTRU may transmit capability information or indications when triggered by an LCS client / application in the WTRU (e.g., MO-LR) or in the network (e.g., MT-LR, delayed MT-LR, NI-LR). The LCS client / application may provide a reference time (e.g., scheduled location time), a reference location, and / or an expected trajectory of the WTRU. The WTRU may receive an indication from the LCS client in one or more of the following: an LCS message, an LPP message, or AS layer signaling / channel (e.g., RRC, MAC CE, downlink control information (DCI), data, etc.). When an LPP request message is received from the network, the WTRU may transmit capability and / or assistance information. The request message may include a request for information related to measurements, WTRU power saving modes, trajectories, reference location / time, accuracy attributes, etc.

[0128] For detecting reference locations and / or times, the WTRU may transmit capability information and / or indications when one or more reference locations (eg, PRU location areas) and / or at reference time instances (eg, scheduled location times) are detected.

[0129] For periodicity of triggering events and / or conditions, the WTRU may transmit capability information and / or indications periodically (e.g., possibly based on one or more periodicity values ​​configured by the network). When a change (e.g., any change) in capability and / or assistance information is detected (e.g., relative to a previous opportunity when the information may have been transmitted), the WTRU may transmit updated / new capability and / or assistance information.

[0130] For radio condition or sensor measurement changes, the WTRU may transmit capability information and / or indications when triggered by a radio condition change detectable at the WTRU. The WTRU may be configured to perform measurements or sensor measurements on DL-PRS / CSI-RS / SSB. The WTRU may transmit information when a measurement value (e.g., RSRP, received signal strength indicator (RSSI), magnetic field measurement, device orientation) increases or decreases by certain corresponding thresholds.

[0131] The WTRU may transmit an indication and / or information (e.g., possibly based on the triggering event / condition described above) to the network (e.g., gNB, LMF). The indication and / or information transmitted by the WTRU may include one or more of the following: capability information, a request for assistance information, a request for a new / updated SRSp / PRS configuration, a request to activate a pre-configured SRSp / PRS configuration, an indication for notifying the start of SRSp transmission or the start of PRS measurement, or an indication of a detected triggering event. The WTRU may transmit the indication in RRCCONNECTED state, RRCINACTIVE, or RRCIDLE state. In an example, when the WTRU is in low power operation (e.g., INACTIVE state / mode / operation), the WTRU may transmit the indication in the SDT using RACH or CG resources associated with the SDT. In an example, when the WTRU is in IDLE state, the WTRU may transmit the indication in an initial access / RACH message (e.g., RRCRequest, RRCSystemInformation request, RRCReconfiguration request, or a RACH / RRC message associated with positioning). The WTRU may transmit an indication when in IDLE in a RACH opportunity (e.g., possibly associated with positioning). When transmitting an indication in the INACTIVE / IDLE state, the WTRU may include a flag, information, and / or used resources associated with low power positioning (e.g., SDT) so that the WTRU may not be transitioned to the CONNECTED state. When transitioning to the CONNECTED state, the WTRU may transmit an indication to the network (e.g., possibly due to non-positioning or positioning related reasons).

[0132] An example of a WTRU receiving assistance data for LPHAP operation is provided herein. When assistance data associated with LPHAP and / or other positioning examples / schemes (e.g., DL-based, UL-based, DL+UL-based, GNSS, etc.) is received, the WTRU may perform any procedures, functions, and operations associated with LPHAP. The assistance data may be received in a positioning SIB (e.g., broadcasted with a configured periodicity in a posSIB), an LPP message, or an AS layer signaling / channel (e.g., RRC, MAC CE, DCI, PDSCH, etc.).

[0133] The WTRU may receive assistance data associated with the LPHAP as a result of (eg, via) one or more of: a transmission request, periodically, or detecting configured events and / or conditions.

[0134] For the WTRU to receive assistance data associated with the LPHAP via a transmission request, the WTRU may transmit a request (e.g., an LPP message or AS layer signaling) to the network for assistance data of information, identifiers, configurations, and / or parameters associated with the LPHAP. The WTRU may (e.g., may then) receive the corresponding assistance data. In an example, the WTRU may receive the assistance data (e.g., in an LPP message) after transmitting capability information and / or other indications / messages (e.g., on-demand requests, LCS messages, LPP messages, positioning information / reports, etc.).

[0135] For the WTRU to periodically receive assistance data associated with the LPHAP, the WTRU may be configured by the network to periodically receive the assistance data with a configured periodicity. The WTRU may request a change in the periodicity for receiving the assistance data based on the detection of one or more events, such as a mobility state change (e.g., a change from a stopped state to a moving state) or a trajectory change of the WTRU.

[0136] For a WTRU to receive assistance data associated with LPHAP upon detection of configured events and / or conditions, the WTRU may receive assistance data for LPHAP and / or other positioning methods / schemes (e.g., associated with different IDs) (e.g., which may be stored by the WTRU (e.g., in context information) and retrieved for future positioning procedures / sessions (e.g., LPP sessions)). The WTRU may (e.g., may also) receive validity conditions (e.g., positioning area and / or time validity) and / or events associated with storing, using and / or releasing assistance data. The WTRU may use the preconfigured assistance data as long as the validity conditions are active / valid and / or the WTRU has not detected an event that invalidates the preconfigured assistance data. The WTRU may receive updated / new assistance data when the validity conditions expire and / or an event that invalidates the preconfigured assistance data is detected by the WTRU (e.g., possibly based on an indication transmitted by the WTRU to the network reporting the expiration of the validity condition, the detection of the event, and / or a request for new / updated assistance data).

[0137] The assistance data received by the WTRU may include one or more of the following: time window / interval of measurement mode and / or estimation mode; measurement mode configuration (e.g., PRS configuration for LPHAP); estimation mode configuration; priority of measurement and / or estimation configuration; error threshold (e.g., used to determine whether accuracy requirements are met); correction information (e.g., used to recover from measurement / estimation errors); or reporting configuration.

[0138] For assistance data received by the WTRU including time windows / intervals for measurement mode and / or estimation mode, the WTRU may receive information about one or more time windows and / or intervals (e.g., including a start time slot / instance, an offset time relative to a reference time slot, a duration, a stop time slot / instance) indicating when the WTRU may operate in measurement mode (e.g., perform measurements of DL-PRS or transmission of SRSp) or operate in estimation mode (e.g., perform sensor measurements, tracking of trajectories). The time windows may correspond to information about when the WTRU may perform prediction / extrapolation and / or smoothing / interpolation of the WTRU position (e.g., when in estimation mode). The WTRU may receive information about different time windows associated with durations for performing measurements and / or using measurements to perform prediction / extrapolation and / or smoothing / interpolation of the WTRU position. In an example, a first time window with a 10 ms measurement interval may be used to perform prediction of the expected WTRU position 1 ms in advance. In an example, a second time window with a 5 ms measurement interval may be used to perform prediction of the expected WTRU position 0.5 ms in advance. The WTRU may receive information about a time to live indicating a time window / interval that the LMF / LCS client / application may tolerate when there may be lost, delayed, or no positioning reports and / or information transmitted by the WTRU. During the time to live, the WTRU / LMF may perform interpolation / smoothing to determine the WTRU position in intermediate time instances between different positioning reports and / or information transmitted by the WTRU.

[0139] For assistance data received by the WTRU including a measurement mode configuration (e.g., a PRS configuration for LPHAP), the WTRU may receive one or more of the following: a PRS configuration and / or parameters (e.g., an ID); and / or an SRSp configuration and / or parameters (e.g., which may be associated with or intended for LPHAP and / or power saving mode operation (e.g., for use during INACTIVE / IDLE mode)). The PRS / SRSp configuration may include one or more frequency layers, resources, resource sets, beams, or TRPs / gNBs associated with the indicated PRS / SRSp configuration. In an example, one or more PRS / SRSp configurations for LPHAP may include a combination of a relatively low / high number of frequency layers, bandwidth (frequency resources), periodicity, resource density, number of beams, number of TRPs / gNBs, etc. The types of PRS / SRSp configurations received by the WTRU may include aperiodic, semi-persistent, and / or periodic, as well as timing information associated with different types (such as start time / slot, periodicity, and / or stop time / slot). The WTRU may (e.g., may also) receive information (e.g., IDs) regarding one or more measurement gap configurations, which may be associated with a PRS configuration to be used during measurement mode and / or estimation mode. Such measurement gap configurations may be activated during operation in measurement mode and / or estimation mode.

[0140] For assistance data received by the WTRU including an estimation mode configuration, the WTRU may receive trajectory information associated with the WTRU and / or another device (e.g., a robot, an asset, a vehicle) to which the WTRU may be attached or co-located. In an example, the trajectory information may correspond to one or more locations (e.g., coordinates) associated with different scheduled time instances (e.g., time 1: location 1, time 2: location 2, time 3: location 1). In an example, the trajectory information may include different trajectory types (e.g., a straight path, a curve to the left, a curve to the right), which may be associated with different scheduled time instances. The trajectory information may be associated with one or more PRS / SRSp configurations (e.g., if a corresponding location and / or time instance indicated in the trajectory is detected, it may be used by the WTRU to perform measurements and / or transmissions).

[0141] The WTRU may receive one or more of: trajectories (e.g., preconfigured), where each trajectory or subset of trajectories may be associated with an ID; and / or information about which trajectory / subset of trajectories the WTRU is expected to use / follow (e.g., possibly at different time instances / windows). When reporting information about actual and / or estimated trajectories followed by the WTRU, the WTRU may transmit information about the trajectories / subsets of trajectories to the network. For example, in the event that there may be uncertainty in the current or expected trajectory (trajectory / subset of trajectories) followed by the WTRU, the WTRU may determine one or more trajectories that may best match the preconfigured trajectories received from the network (e.g., the difference between the preconfigured trajectory and the actual / expected trajectory (possibly in terms of position on the path) is less than a threshold). The WTRU may indicate information about the determined trajectories (e.g., IDs) to the network, possibly together with confidence / weight / probability values ​​associated with different determined trajectories.

[0142] The WTRU may receive assistance data associated with a time window indicating when the WTRU may operate in estimation mode. The assistance data may (e.g., may also) include location information of cells / TRPs / gNBs / positioning areas that may be expected to be detected by the WTRU at future time instances. Such information may be received and / or reported by the WTRU in advance and / or when the location / time instance is detected. The information reported by the WTRU regarding the detected cells / TRPs may be used to assist the network in improving the accuracy of the prediction of the WTRU's location.

[0143] For assistance data received by the WTRU including priorities for measurement and / or estimation configurations, the WTRU may receive a priority value associated with a measurement mode and / or an estimation mode. Within each mode, the WTRU may (e.g., may also) receive a priority value associated with a PRS / SRSp configuration and / or a trace configuration. The WTRU may select a mode and / or associated configuration based on a priority order, wherein if multiple configurations are indicated / available, the PRS / SRSp / trace configuration with the highest priority may be used first for measurement and / or estimation.

[0144] For assistance data received by the WTRU that includes error thresholds (e.g., for determining whether accuracy requirements are met), the WTRU may receive one or more error thresholds associated with measurements (e.g., RSRP threshold, number of multipaths) and positioning QoS (e.g., accuracy, integrity, latency). For example, when determining / predicting / smoothing the WTRU position at different time instances, the WTRU may use the error thresholds to determine whether positioning QoS requirements are met.

[0145] For assistance data received by the WTRU including correction information (e.g., for recovering from measurement and / or estimation errors), the WTRU may receive correction and / or compensation information to be applied when operating in measurement mode and / or estimation mode. If recovering from an error condition when the measurement and / or estimation is invalid, the WTRU may (e.g., also) receive correction and / or compensation information to be applied when operating in measurement mode and / or estimation mode. In an example, the correction information may be related to a timing / phase error (e.g., associated with a TRP / gNB and / or PRS / SRSp resource), which indicates the difference between the time instance / phase when the PRS / SRSp is generated and sent by the TRP / gNB or WTRU. In an example, the correction information may be related to the timing / phase error expected at different positioning areas and / or time instances. When performing measurement of PRS, transmission of SRSp, estimation or prediction of the WTRU position, the WTRU may use corresponding correction information based on one or more of the PRS / SRSp resource, TRP / gNB, area, time instance.

[0146] For assistance data received by the WTRU including a reporting configuration, the WTRU may receive a reporting configuration to apply when transmitting information about positioning measurements and / or positioning estimates / predictions (e.g., when operating in measurement mode and / or estimation mode). In an example, the reporting configuration may include an ID to be used (e.g., LPP ID, WTRU ID, positioning instance / scheme ID, power saving mode ID). In an example, the reporting configuration may include whether to report absolute / average / minimum / maximum values ​​related to measurements made on the PRS (e.g., resources / beams associated with the PRS configuration) and / or measurements made by sensors. The reporting configuration may include a reporting periodicity (e.g., whether the report will be aligned with the measurement and / or transmission), an offset for the start and / or end of the measurement, and an event that the WTRU may monitor / detect to transmit a report to the network. The WTRU may transmit a report about the positioning measurement, estimate, prediction, and / or uncertainty if one or more of the following is detected: a change in radio conditions (e.g., RSRP is above / below a threshold), a change in mobility state, or a change in WTRU trajectory (e.g., the WTRU deviates from a straight path). The WTRU may include timing information (e.g., timestamp) in the report (e.g., to indicate whether measurement and / or estimation started / stopped). When the WTRU performs prediction / extrapolation and / or smoothing / interpolation, the WTRU may transmit timing information (e.g., timestamp) related to the start time, duration, and / or stop time associated with the prediction / smoothing. When performing extrapolation / interpolation of the WTRU position, the WTRU may transmit information about the uncertainty of the prediction / smoothing, confidence values, and / or weight values ​​associated with different instances of the extrapolated / interpolated position value.

[0147] The assistance data received by the WTRU may be common across different positioning areas (e.g., including multiple cells / TRPs / gNBs), or specific to one or more cells / TRPs / gNBs. When the WTRU receives cell / TRP-specific assistance data (e.g., associated with the ID of a cell / TRP), the WTRU may use the associated assistance data under the coverage of that cell / TRP.

[0148] The WTRU may receive an indication and / or information to the network (e.g., gNB, LMF) (e.g., which may be based on one or more of the triggering events / conditions described above). The indication and / or information received by the WTRU may include one or more of the following: a request for capability information, a request for assistance information, assistance information, a new / updated SRSp / PRS configuration, an activation / deactivation indication of one or more pre-configured SRSp / PRS configurations, an indication of the start of initiating SRSp transmission or the start of PRS measurement, or an acknowledgement / rejection indication of a request transmitted by the WTRU (e.g., any request). The WTRU may receive the indication in RRC CONNECTED state, RRC INACTIVE, or RRC IDLE state. In an example, if the WTRU is INACTIVE, the WTRU may receive an indication in a DL-SDT message (e.g., via an activated SDT configuration, a DL-SDT RACH response, SPS-SDT, RRCRelease, etc.). In an example, if the WTRU is IDLE, the WTRU may receive an indication in an RRC message (e.g., RRCSetup, RRCReconfiguration, etc.) or a RACH response message. The WTRU may receive an indication in an updated SIB that, when transmitted to the network, may be accessed by the WTRU after a certain configured duration (e.g., expiration of a timer).

[0149] An example of a WTRU switching between different positioning modes based on a switching criterion is provided herein. The WTRU may switch between a measurement mode and an estimation mode based on detecting one or more conditions and / or triggering events in one or more switching criteria. The switching criteria may be received by the WTRU semi-statically (e.g., as a configuration) or dynamically from the network (e.g., in a posSIB, LPP message, RRC signaling, MAC CE) as auxiliary information. The WTRU may transmit (e.g., in the case of dynamic reception) a request message (e.g., an on-demand request) and / or an activation indication for requesting activation of a preconfigured switching criterion.

[0150] The WTRU may apply switching criteria for switching between measurement mode and estimation mode if one or more of the following triggering events / conditions are detected: measurement accuracy / completeness, indication from the network / application / higher layers, expiration of restrictions in the PRS / SRSp configuration and associated validity conditions, errors during estimation / measurement, power saving state change, trajectory and / or mobility state change, or periodicity (e.g., detection timer).

[0151] For the WTRU to detect measurement accuracy / integrity, the WTRU may switch between modes when the determined positioning accuracy / integrity value is greater than or less than one or more accuracy / integrity thresholds (e.g., as may be received from the network). When the accuracy associated with the sensor measurement is less than the threshold, the WTRU may switch to the measurement mode.

[0152] For the WTRU to detect an indication from the network / application / higher layer, the WTRU may switch between modes when an explicit or implicit indication is received indicating a switch to a different positioning mode currently applied. The explicit indication received by the WTRU may include an identifier associated with the positioning mode (e.g., DL-PRS ID, UL-SRSp ID, estimation mode ID). The implicit indication received by the WTRU for switching may include a paging message, a wake-up signal, a low power trigger indication, a Ran RC reconfiguration message, a PDCCH (DCI) indicating the presence of data, a trigger of an SR / BSR for data transmission, etc. When a wake-up signal is received, the WTRU may switch from the estimation mode to the measurement mode for performing DL-PRS measurements or UL-SRSp transmissions.

[0153] For the WTRU to detect limitations in the PRS / SRSp configuration and the expiration of the associated validity conditions, the WTRU may switch between modes when the number of TRPs, number of frequency layers, beams, resource sets, or amount of resources available via the PRS / SRSp configuration is greater than or less than one or more thresholds. The WTRU may switch to the estimation mode when the WTRU detects that the number of TRPs from which PRS with RSRP above the RSRP threshold is received is below the threshold. The WTRU may switch to the estimation mode when the validity conditions associated with the PRS / SRSp configuration expire (e.g., TA timer expires, change in RSRP of spatially correlated RS is above / below a threshold, WTRU leaves the validity area, timer expires).

[0154] For a WTRU that detects an error during estimation and / or measurement, the WTRU may switch between modes when an estimate of the WTRU position based on sensor measurements or DL-PRS measurements is greater than or less than one or more error thresholds. The WTRU may switch to estimation mode when an explicit or implicit indication is received from the network that the error due to UL-SRSp transmission is below a threshold. In an example, the WTRU may switch to estimation mode when an RSRP measurement of a RS (e.g., which is spatially correlated with a SRSp (e.g., DL-PRS, SSB)) is less than a threshold.

[0155] For the WTRU to detect a power saving state change, the WTRU may switch between modes when transitioning between the RRC CONNECTED state, the RRC INACTIVE state, the RRC IDLE state and / or any other power saving state.

[0156] For a WTRU to detect a trajectory and / or mobility state change, the WTRU may switch between modes when the mobility state (e.g., any mobility state) of the WTRU changes (e.g., stationary, speed level in different speed ranges with different upper and lower limits). The WTRU may switch between modes when the trajectory of the WTRU changes (e.g., the WTRU position deviates by a certain threshold relative to the expected position in the expected trajectory).

[0157] For the WTRU to detect periodicity (e.g., detect a timer), the WTRU may periodically switch between modes based on the configured / determined periodicity. The WTRU may use high / low switching periodicity based on the mobility state change of the WTRU (e.g., when the speed of the WTRU increases above a threshold, the WTRU uses a high switching periodicity, and when the speed is low or remains stable, the WTRU uses a low periodicity). The WTRU may switch between modes when a timer (e.g., with a configured duration) is set and / or expires.

[0158] When switching / changing from using a first set including one or more PRS / SRSp configurations to using a second set of one or more PRS / SRSp configurations, a triggering event / condition (e.g., similar triggering events / conditions as described above) may apply. Such switching / changing between PRS / SRSp configurations may be performed while operating in measurement mode and / or estimation mode.

[0159] The WTRU may be preconfigured with one or more positioning QoS requirements (e.g., accuracy, latency, low power operation, integrity), where different positioning QoS may be associated with different positioning modes (e.g., measurement / estimation mode), IDs and / or priority values. When switching from a first mode to a second mode, the WTRU may use the positioning QoS associated with the second mode, which may be based on the order of priorities associated with the positioning QoS. When switching between different positioning modes, the WTRU may (e.g., may also) use different reporting configurations.

[0160] The WTRU may partially operate in measurement mode and estimation mode upon detecting one or more conditions and / or events described in the handover criteria. Upon detecting the availability of limited PRS configurations (e.g., limited number of TRPs with high RSRP, limited bandwidth), the WTRU may supplement / augment the limited measurements by operating (e.g., simultaneously) in estimation mode (e.g., using sensor measurements). Upon determining limited PRS measurements, the WTRU may increase the time window / interval for operating in estimation mode, where PRS measurements may be performed over a reduced time window / interval.

[0161] The WTRU may be configured with a total time window indicating a maximum / minimum time interval for performing measurements or estimates. The WTRU may determine a switching time instance and / or associated time interval for operating in a measurement mode and / or an estimation mode within the configured total time window. The WTRU may determine the switching time instance and / or interval based on one or more conditions associated with the measurement and / or estimation mode, including achievable accuracy, measurement quality (e.g., high / low RSRP, number of multipaths), presence of errors (e.g., timing / phase / sensor errors), or achievable power savings.

[0162] In WTRU-based mode and / or WTRU-assisted mode, when switching between measurement and / or estimation mode, the WTRU may transmit an indication to the network (e.g., in an LPP message, RRC signaling, MAC CE, UCI), possibly along with the estimated / determined location information and / or measurement and timing information (e.g., timestamp) at the time of the switch. The WTRU may (e.g., may also) transmit the reason for the switch (e.g., cause ID, event ID) in the indication.

[0163] An example of a WTRU performing LPHAP based on trajectory information is provided herein. The WTRU may determine location information while operating in a combination of measurement mode and estimation mode based on trajectory information while ensuring that positioning QoS (e.g., accuracy) requirements are met. The WTRU may use the trajectory information to determine whether the location information of the WTRU determined via measurement and / or estimation is within an expected trajectory. The WTRU may (e.g., may also) use the trajectory information to perform corrections to the estimated WTRU position (e.g., without performing measurements).

[0164] The WTRU may receive trajectory information or a subset of information (e.g., associated with the WTRU and / or another device / WTRU) from a network / application (e.g., LCS client) in an LCS message, an LPP message, or AS layer signaling (e.g., RRC, MAC CE, DCI, etc.), which may be attached to or in the vicinity of the WTRU. The trajectory information may include a set of expected locations (e.g., coordinates) and / or a set of expected time instances (e.g., scheduled location times) indicating where / when the WTRU may be located. The trajectory information may (e.g., may also) indicate where / when the WTRU may operate in a measurement mode and / or an estimation mode. The trajectory information may (e.g., may also) include different IDs, precisions, and / or error parameters, which may be associated with different locations and / or time instances indicated in the trajectory.

[0165] The WTRU may receive trajectory information from the network (e.g., gNB, LMF). When the WTRU receives a request for a trajectory from the network, the WTRU may transmit the trajectory information to the network. The trajectory information may include at least one of: a movement trajectory (e.g., straight line, curve), acceleration, velocity, movement direction (e.g., north, west, east, south, angle), or parameters required to represent the movement of the WTRU (e.g., dynamic model parameters such as velocity, acceleration, covariance matrix of noise in the model, parameters in the observation model, etc.).

[0166] If the WTRU receives trajectory information from the network or the WTRU is preconfigured with trajectory information from the network, the WTRU may determine to use this information to perform prediction or smoothing of position information based on the WTRU's positioning (e.g., to correct past position estimates). If the WTRU transmits position information, the WTRU may (e.g., may also) indicate to the network which model (e.g., an identifier associated with the model) the WTRU has used to perform the prediction or smoothing (e.g., a straight line trajectory was used to predict future position information). The WTRU may (e.g., may also) indicate in the report the prediction interval or smoothing interval (e.g., prediction of position N symbols / slots / frames / milliseconds ahead of the time when the position information is reported, smoothed / interpolated position information N symbols / slots / frames / milliseconds ahead of the time when the position information is reported).

[0167] The WTRU may include information associated with a predicted or smoothed position at multiple time instances. The WTRU may include a future or past timestamp of information associated with a predicted or smoothed position for one or more of the multiple time instances. The WTRU may (e.g., may also) include model information associated with a predicted or smoothed position for each of the multiple time instances. The WTRU may include predicted WTRU position information at T milliseconds, 2T milliseconds, and 3T milliseconds from the timestamps that the WTRU includes in the measurement report. The WTRU may include the associated predicted position information in the report (e.g., T milliseconds, 2T milliseconds, and 3T milliseconds in the report).

[0168] The WTRU may explicitly indicate to the network that the model used to derive location information (e.g., current, predicted, smoothed WTRU location) is the same as the model used in the last report. By indicating to the network that the model has not changed, overhead for signaling may be saved.

[0169] An example of LPHAP applied by the WTRU based on trajectory information may be as follows. The WTRU may receive trajectory information (e.g., expected position and / or time instances t0, t1, ... ti) from the network. At time instance t0, when operating in measurement mode, the WTRU may perform measurements of the DL-PRS for a configured duration and determine its actual position. The WTRU may determine the difference / error between its determined actual position and the expected position at t0 indicated in the trajectory information. The WTRU may apply the error to correct the actual position for calibration purposes. The WTRU may switch to estimation mode operation. At time instance t1, when in estimation mode (e.g., applying sensor measurements), the WTRU may estimate its position based on the previously determined actual position (e.g., at t0) and tracking of sensor measurements (e.g., speed, direction, number of instances where the direction was changed, time elapsed since each instance of speed change, and direction may be detected). When the WTRU detects an event and / or condition for changing to measurement mode (e.g., sensing accuracy change, expiration of a timer, periodicity), the WTRU may switch to measurement mode and perform measurements of the DL-PRS (e.g., possibly using a PRS configuration associated with the most recent location and / or time instance (e.g., t1) indicated in the trajectory). When the WTRU detects an event and / or condition for changing to measurement mode (e.g., sensing accuracy change, expiration of a timer, periodicity), the WTRU may determine its updated actual location based on the measurements, and may determine a difference between the updated actual location and the estimated location. When the difference between the actual location and the estimated location is less than a threshold, the WTRU may transmit an indication to the network indicating that its location is within the expected trajectory. When the difference between the actual location and the estimated location is greater than a threshold, the WTRU may transmit an indication to the network indicating an error (e.g., a difference in location information) and / or a request for an updated trajectory. If the WTRU does not detect an event for changing to measurement mode, the WTRU may continue to operate in estimation mode until the next time instance (e.g., t2).

[0170] An example of a WTRU performing LPHAP when triggered by a paging message is provided herein. The WTRU may initiate LPHAP based on the receipt of a paging message by triggering operations in a measurement mode (e.g., performing PRS measurements or SRSp transmissions) and / or an estimation mode (e.g., sensor measurements, predictions). Paging-based triggering for LPHAP may be intended to minimize or eliminate signaling associated with operations in the RRC CONNECTED state and establishing and / or maintaining connectivity with a serving cell / gNB. For example, when operating in a power saving mode (e.g., in an INACTIVE / IDLE state), such methods may enable the WTRU to perform positioning procedures for an extended duration. The paging message may be a paging message for paging the WTRU when there is data to be transmitted in the DL, or a paging message for positioning purposes (e.g., with a different ID).

[0171] The WTRU may receive configuration information associated with one or more positioning areas (e.g., in assistance data), where each positioning area may include one or more cells / TRPs / gNBs. The positioning area may be associated with one or more identifiers and priority values. The positioning area may be associated with / overlap with one or more tracking areas (TAs) and / or RAN paging / notification areas (RNAs). For DL-based methods, the TRPs / gNBs in the positioning area may be associated with at least one PRS configuration from which the WTRU may receive DL-PRS for measurement. Similarly, for UL-based methods, the TRPs / gNBs in the positioning area may be associated with at least one SRSp configuration, which may have been configured by the network for performing measurements of SRSps sent by the WTRU. The paging message received by the WTRU may be received from one or more TRPs / gNBs associated with the positioning area. The paging message information / identifier may be associated with a positioning area (e.g., which may be, may include, or may be associated with an area ID) in which the WTRU may perform DL-PRS measurements and / or UL-SRSp transmissions (e.g., in this case).

[0172] The WTRU may (e.g., may also) receive one or more DRX configurations associated with the positioning area / TA / RNA, including parameters associated with the DRX cycle duration, the DRX on-duration, the DRX inactivity timer, etc. A WTRU in low power operation (e.g., INACTIVE / IDLE state / operation / state) may wake up according to the active DRX configuration to receive a DL paging message during the DRX on-duration.

[0173] The paging message received by the WTRU for triggering LPHAP may include one or more of the following. The paging message may include an identifier associated with the WTRU (e.g., WTRU ID, C-RNTI, group ID, group RNTI). The paging message may include information about the identifier / preamble to be used when transmitting a measurement report and / or sending an SRSp (e.g., the paging message may include configuration information (ID) applied by the WTRU when generating the preamble / WTRU ID, and when sending the SRSp, the WTRU may scramble the generated preamble / WTRU ID in the SRSp resource). The paging message may include an identifier associated with the PRS / SRSp configuration and / or parameters to be applied (e.g., the WTRU may be preconfigured with one or more resources for PRS / SRSp, and the WTRU may select the PRS / SRSp resource based on the associated ID received in the paging message). The paging message may include information about the PRS / SRSp / RACH resources / configuration to be used when performing measurements and / or SRS transmissions. The paging message may include information about the positioning mode to be applied (e.g., measurement mode and / or estimation mode). The paging message may include information about the trajectory and / or trajectory subset to be applied / followed (e.g., ID). The paging message may include information about when to start / stop the timing (e.g., offset, duration, periodicity) for initiating PRS measurements, SRSp transmissions and / or sensor measurements / tracking. The paging message may include information about changes in pre-configured PRS configurations / SRSp configurations, changes in positioning areas, and / or changes in scheduled location times.

[0174] When a paging message is received during a paging occasion, the WTRU may initiate a measurement mode (eg, perform PRS measurements, send SRSp) and / or an estimation mode (sensor measurements, tracking) based on information included in the paging message.

[0175] Examples of information transmitted by a WTRU to a network regarding LPHAP operation are provided herein. The WTRU may transmit positioning information / indications / reports (e.g., location measurements / estimations) to the network that may be related to LPHAP. In an example, the WTRU may transmit positioning information regarding LPHAP based on a reporting configuration received in assistance data. In an example, the WTRU may transmit positioning information / reports when a triggering event / condition as described above is detected (e.g., when a request is received from the network, a periodic report, a switch from one to another, an error is detected, etc.). In connection with UL-based LPHAP, the WTRU may transmit indications due to one or more of the following: if an SRSp configuration is requested and / or a pre-configured SRSp configuration is activated / deactivated, if switching between different SRSp configurations is performed, or if positioning information determined via an estimation mode is reported.

[0176] The positioning information / report related to LPHAP may be transmitted by the WTRU based on an event trigger (e.g., periodically or in an aperiodic manner) in at least one of the following: LPP message or AS layer message (e.g., RRC signaling, MAC CE, UCI, PUSCH data, etc.). The positioning information about LPHAP transmitted by the WTRU may include one or more of the following: position information, prediction / smoothing information, error information, achievable positioning QoS, or WTRU mobility / mobility information.

[0177] For location information, the WTRU may transmit the determined / estimated WTRU location (e.g., coordinates, relative position with respect to a reference location / landmark) and / or measurements used to determine / estimate the WTRU location. Such information may be transmitted along with the associated positioning mode applied (e.g., measurement mode and / or estimation mode) and timing information (e.g., timestamp). The WTRU may transmit information about sensor measurements and / or measurements made on RRM signals (e.g., CSI-RS, SSB) made to estimate the WTRU location (e.g., possibly in addition to information about measurements made in the DL-PRS). Such information may be used to improve the accuracy of the WTRU location.

[0178] For prediction / smoothing information, the WTRU may transmit predicted / extrapolated position information (e.g., for a future time instance) and / or smoothed / interpolated position information (e.g., for a previous time instance). The WTRU may transmit timing information (e.g., timestamps) associated with the prediction / smoothing during a duration / window during which the WTRU may apply and / or perform the prediction / smoothing and / or during instances related to when the WTRU may apply and / or perform the prediction / smoothing. The WTRU may (e.g., may also) indicate a confidence level and / or uncertainty associated with the predicted / smoothed position information.

[0179] For error information, the WTRU may (e.g., may also) indicate errors due to time / phase / power / sensor measurements (e.g., timing / phase error group ID), errors associated with prediction / smoothing when using measurement mode and / or estimation mode, and errors regarding the expected trajectory (e.g., the difference between the expected position and the estimated position).

[0180] For achievable positioning QoS, the WTRU may transmit information regarding the achievable positioning QoS (eg, accuracy, integrity, latency, power saving), possibly with respect to requirements and / or KPIs received from the network / application.

[0181] For WTRU mobility / mobility information, the WTRU may transmit information about the mobility state (e.g., stationary, moving with low / high speed), other mobility / mobility attributes (e.g., WTRU speed, direction, distance traveled in a straight / linear path) and / or mobility path (e.g., a list of one or more cells / TRIDs traversed by the WTRU over a duration).

[0182] When operating in low power operation (e.g., INACTIVE / IDLE mode / state / operation), the WTRU may transmit positioning information / reports using a small data transmission (SDT) or early data transmission (EDT) configuration. The SDT / EDT configuration received by the WTRU from the network (e.g., serving gNB) may include information about validity conditions (e.g., TA timer) for maintaining the SDT / EDT, the (e.g., maximum) size of the payload of the message, periodicity, and / or resource grants (e.g., grants of the SDT configuration), etc.

[0183] In order to minimize the amount of reporting and sending of positioning information during LPHAP operation, the WTRU may transmit the difference (e.g., variance) in positioning information relative to the information transmitted in the previous reporting instance. Such differential reporting may (e.g., may also) be used by the WTRU when reporting predicted / smoothed information of the WTRU's position.

[0184] Different types of positioning information (e.g., position information determined via measurement / estimation, error information, etc.) may be associated with different priority values, where the priority values ​​may be received by the WTRU from the network as assistance data. The WTRU may (e.g., in this case) apply different reporting periodicities or urgency levels to transmit positioning information based on the priority associated with the type of information to be reported. The positioning information (which may include a change value greater than a threshold relative to previously reported information) may be transmitted with a higher periodicity or triggered with a higher urgency level (e.g., using an SR / BSR configuration associated with a high priority / URLLC service). The WTRU may transmit information related to errors and / or changes about an expected trajectory with a higher periodicity and / or a higher urgency level.

[0185] When transmitting positioning information with a high priority (e.g., greater than a threshold), the WTRU may (e.g., may also) indicate or transmit a request message to the gNB to request that the WTRU be transitioned from a low power operation (e.g., INACTIVE / IDLE state / mode / operation) to a CONNECTED state operation. If no estimation / prediction error is detected or a small amount of estimation / prediction error is detected (e.g., less than a threshold), the WTRU may reduce the reporting periodicity by transmitting the combined positioning information saved / stored from a previous time instance.

[0186] The WTRU may be configured with a periodic PRS / SRSp. The periodic PRS / SRSp may be associated with the periodicity of the DRX cycle.

[0187] The WTRU may be configured with one or more DL PRS configurations / resources and / or UL SRSp resources. One or more DL PRS configurations / resources and / or UL SRSp resources may include a periodicity value that may be aligned with the periodicity of the DRX cycle in low power operation (e.g., INACTIVE and / or IDLE state / mode / operation).

[0188] When operating in low power operation (e.g., INACTIVE state / mode / operation), the WTRU may be configured with DRX (e.g., I-DRX), where the periodicity of DL-PRS reception and / or UL SRSp transmission may correspond to N times the periodicity of the DRX cycle. For example, if N=5, the WTRU may receive PRS and / or transmit SRSp in every fifth DRX cycle. For example, if N=1, the WTRU may receive PRS and / or transmit SRSp in every DRX cycle. Such a configuration may allow the WTRU to perform reception and / or transmission of non-positioning signals (e.g., data, control, or paging messages) in a DRX cycle that is not associated with the reception of PRS and / or the transmission of SRSp. Such a configuration may (e.g., additionally) allow the WTRU to perform positioning measurements and / or transmissions less frequently than the reception / transmission of other signals.

[0189] The periodicity of the DRX cycle may correspond to K times the periodicity of DL-PRS reception and / or UL SRSp transmission. If the periodicity of the DRX cycle corresponds to 1, the DRX cycle may use a fractional value (e.g., 1 / N) for the periodicity of DL-PRS reception and / or UL SRSp transmission. If the periodicity of the DRX cycle corresponds to K times the periodicity of DL-PRS reception and / or UL SRSp transmission, the WTRU may perform up to K PRS receptions and / or K SRSp transmissions in the DRX cycle.

[0190] The periodicity of DL-PRS reception and / or UL SRSp transmission may be configured independently of the periodicity associated with the DRX cycle. If the WTRU (e.g., in this case) is configured with PRS and / or SRSp in one or more time slots / opportunities that overlap with the Active / On Duration of the configured DRX cycle, the WTRU may perform PRS measurements and / or SRSp transmissions in the Active Duration as configured. If the WTRU is configured with PRS and / or SRSp outside the Active / On Duration of the configured DRX cycle, the WTRU may wake up in one or more time slots / opportunities for one or more of: monitoring signaling associated with positioning (e.g., any signaling), receiving PRS, or transmitting SRSp.

[0191] The WTRU may be preconfigured with one or more periodicity values ​​for PRS and / or SRSp. The WTRU may (e.g., may also) be preconfigured with associated trigger conditions / events. The associated trigger conditions / events may be monitored by the WTRU to determine the appropriate periodicity value to be applied (e.g., when the trigger conditions / events occur, the corresponding periodicity value may be applied). In an example, the WTRU may be configured with a first periodicity value and a second periodicity value for PRS and / or associated information indicating an association with a DRX configuration configured in the WTRU. When a first DRX configuration (e.g., a long DRX cycle) is applied, the WTRU may (e.g., in this case) use the first periodicity value for PRS measurements (e.g., high periodicity with multiple PRSs in a single DRX active duration). When a second DRX configuration (e.g., a short DRX cycle) is applied, the WTRU may use the second periodicity value for PRS measurements (e.g., low periodicity of PRSs occurring after multiple DRX cycles).

[0192] The WTRU may receive periodic configuration values ​​for PRS and / or SRSp from the network (e.g., LMF and / or gNB) if in CONNECTED state and / or if transitioning to low power operation (e.g., INACTIVE / IDLE state / mode / operation) (e.g., via an RRC release message). In an example, if in low power operation (e.g., INACTIVE / IDLE state / mode / operation), the WTRU may receive periodic configuration values ​​for PRS / SRSp via one or more of: MT-SDT, paging message, RRC message, MAC CE, or DCI. Such periodic configuration values ​​may be received by the WTRU from the network based on information and / or indication of the DRX configuration (e.g., periodicity, cycle duration, on / active duration) and / or changes in DRX parameters provided by the WTRU to the network.

[0193] Examples are provided herein for supporting DL-based LPHAP. When LPHAP is supported, the WTRU may utilize DL-based positioning to mitigate positioning errors. A WTRU operating in measurement mode and / or estimation mode may provide (e.g., may ensure) low positioning errors and high power savings when limited DL measurements or no DL measurements (e.g., DL-PRS, CSI-RS, SSB) are performed. Positioning errors may be caused by errors or inaccuracies in determining the initial and / or reference position of the WTRU (e.g., possibly at a reference time instance). This may be due to errors caused by one or more insufficient or inaccurate DL-based measurements (e.g., low bandwidth, low number of TRPs), errors in hardware / devices (e.g., applied sensors), or errors in the radio environment (e.g., high number of multipaths, unavailability of LOS paths). As a result of positioning errors at the initial / reference position, at the time (e.g., each time instance) when the WTRU estimates the position (e.g., when in estimation mode) based on previous estimates and / or measurements, the error value may fluctuate, increase, and drift to subsequent time instances where an estimate may be made.

[0194] To mitigate positioning errors, the WTRU may receive assistance data from the network / application, which includes at least one of: one or more DL-PRS configurations (e.g., associated with different accuracy levels, resource amounts, priorities, etc.); one or more trajectories and / or components / subsets of trajectories that the WTRU is expected to follow (e.g., with corresponding IDs); correction information for correcting measurements made in determining a reference position of the WTRU; or one or more thresholds associated with positioning errors.

[0195] The WTRU may perform initial measurements on the DL-PRS to determine a first reference position of the WTRU at a reference time instance t0. The WTRU may provide (e.g., may ensure) high accuracy when determining the reference position by using at least one DL-PRS configuration associated with high accuracy (e.g., high bandwidth, high periodicity, high number of TRPs) and / or applying correction information. The WTRU may receive one or more DL-PRS configurations (e.g., in posSIB or dedicated LPP signaling) that may be intended for use by the WTRU based on one or more of: the type of position (e.g., reference position or intermediate position), the time instance / duration, the mobility state (e.g., stationary, low speed or movement less than a speed threshold, high speed or movement greater than a speed threshold), or the expected level of accuracy at which measurements may be taken to determine a prediction of the WTRU's position. To determine the reference position, the WTRU may select and / or use a first DL-PRS configuration or parameters associated with achieving high accuracy. To determine an intermediate position (e.g., any intermediate position), the WTRU may use a second DL-PRS configuration or parameters associated with a medium level of accuracy. The selection of a DL-PRS configuration and / or parameters (e.g., similar selection) may be performed by the WTRU based on the mobility state. When selecting a DL-PRS configuration, the WTRU may indicate to the network (e.g., in an on-demand request message or a request activation message) the selected configuration and / or parameters associated with the configuration (e.g., an ID of the configuration or parameters).

[0196] The WTRU may estimate and / or predict its expected position at a future time instance t1 based on the determined reference position and the expected trajectory. For example, the WTRU may apply a prediction model to predict the expected position at time instance t1. The prediction model may include information related to the aggregated and / or expected speed, direction, and orientation of the WTRU at different time instances between t0 and t1 (e.g., which may be indicated in the expected trajectory or determined by the WTRU based on tracking). The WTRU may operate in an estimation mode between t0 and t1, which may be used to save power by not performing or performing limited measurements of PRS. The WTRU may select (e.g., after reaching the expected position at t1) an appropriate DL-PRS configuration (e.g., associated with the area where the WTRU may be located and / or the mobility state of the WTRU) and / or perform measurements of PRS to determine the actual position. The WTRU may (e.g., may also) use the measurement and / or tracking information determined during the estimation mode to determine the actual position at t1. In an example, the determined actual position may correspond to the second reference position.

[0197] The WTRU may (e.g., may then) determine a difference between the estimated / predicted position and the actual position at t1 for identifying an error in the prediction model, trajectory, and / or measurement. When the determined error is less than or equal to an error threshold, the WTRU may apply the determined error as feedback information to correct the prediction model, trajectory, and / or measurement. The WTRU may transmit an indication to the network with status information regarding the WTRU position and / or the determined error. The WTRU may (e.g., may also) apply the error to correct previous estimates of the WTRU position at intermediate time instances (e.g., between t0 and t1). When the determined error is greater than the error threshold, the WTRU may transmit an indication to the network indicating information regarding the determined error, the WTRU position, a request for an updated DL-PRS configuration, updated trajectory information, etc. For example, the WTRU may (e.g., may also) reset the reference position and / or tracking of the reference time instance (e.g., to t0) based on the determined error level (e.g., possibly for using a DL-PRS configuration with a different periodicity). The WTRU may use a first DL-PRS configuration (e.g., with high periodicity) at a first reference location. When the error corresponding to the difference between the estimated / predicted location and the actual location (e.g., at or close to a second reference location) is less than a threshold, the WTRU may (e.g., may then) use a second DL-PRS configuration (e.g., with low periodicity) at a second reference location. Otherwise, when the error is greater than the threshold, the WTRU may use the first DL-PRS configuration (e.g., with high periodicity) at the second reference location.

[0198] Examples of WTRUs performing LPHAP based on location-dependent configurations and / or resources are provided herein. The WTRU may perform LPHAP using DL-based configurations and / or resources that may depend on a positioning area or zone that overlaps and / or is close to the coverage area in which the WTRU is located. The location-dependent configurations and / or resources may be one or more DL-PRS configurations, parameters and / or resources used to send reports / indications to the network in the UL, which may be associated with different positioning areas. Each positioning area (e.g., in this case) may include one or more cells / TRPs / gNBs from which the WTRU receives DL-PRS for measurements and / or resource grants for reporting (e.g., if operating in low power operation (e.g., INACTIVE / IDLE state / mode / operation)). Different TRPs / gNBs may be common across different positioning areas, or may be non-overlapping and / or specific to certain positioning areas.

[0199] The WTRU may receive pre-configured information regarding an association between one or more of the following: an association between positioning areas (e.g., area IDs), between cells / TRPs / gNBs (e.g., TRP IDs, PCIs), between DL-PRS configurations / resources (e.g., configuration / parameter IDs), or between UL resources used to transmit reports / indications (e.g., configured grants). The WTRU may (e.g., may also) receive area / time validity conditions, and / or information regarding an association between validity conditions, between positioning areas, and between configurations / resources. Such association information may be received by the WTRU via a posSIB (e.g., via a broadcast from one or more TRPs / gNBs in the positioning area), an LPP message, or an AS layer message (e.g., in RRC, MAC CE, DCI) (e.g., when the WTRU is in RRC CONNECTED state). The association information may be stored in the WTRU or may be received when in RRC INACTIVE / IDLE state (e.g., via SDT). A WTRU that may be in proximity to one or more TRPs / gNBs in the positioning area may select at least one DL-PRS configuration. The WTRU may perform measurements on the PRS using the selected configuration.The WTRU may support such procedures for positioning while in RRC INACTIVE / IDLE state (eg, may not have to establish a connection (eg, any connection or signaling) with the network).

[0200] The WTRU may predict the DL-PRS configuration to be applied at future locations and / or time instances based on previous and / or current positioning areas, association information between DL-PRS configurations and positioning areas, and expected WTRU trajectories. When entering a positioning area (e.g., entering a new positioning area when a new cell / TRP / gNB ID is detected), the WTRU may determine the DL-PRS configuration to be applied based on the prediction. Such an approach may be useful for the WTRU to directly perform measurements using the determined / predicted DL-PRS configuration without having to receive additional SIBs or establish connectivity with the network.

[0201] Different positioning areas may (e.g., may also) be associated with different DL-PRS configurations / parameters, which may be associated with different positioning QoS requirements (accuracy, latency, integrity, etc.) and / or radio conditions (e.g., RSRP measurements, LOS / NLOS, multipath, etc.). In an example, given a set of different DL-PRS configurations associated with positioning areas in which the WTRU may be located, the WTRU may select a DL-PRS configuration or parameter from the set based on the positioning QoS that is expected to be achieved. The WTRU may select a DL-PRS configuration or parameter from the set based on whether RSRP measurements and / or multipath detections performed on the DL-PRS or RS (e.g., which may be spatially correlated with the DL-PRS) are less than / greater than one or more thresholds.

[0202] Different PRS configurations associated with a positioning area received by the WTRU (e.g., in association / assistance information) may include at least two subsets of resources and / or parameters (e.g., periodicity, duration). The first subset and the second subset may be within the same resource pool associated with the PRS configuration and / or may be from different resource pools (e.g., the first subset may be RRM resources and the second subset may be DL-PRS), which may be spatially / QCL related to each other. The first subset may be used by the WTRU to perform limited measurements during LPHAP operation (e.g., in measurement mode or estimation mode) and / or to determine the suitability of the associated DL-PRS for meeting positioning QoS requirements. The resources and / or parameters in the first subset and the second subset may be overlapping or non-overlapping. For example, the first subset may include limited resources, while the second subset may include remaining and / or extended resources associated with the PRS configuration. The amount / number of resources in the first subset may vary depending on the level of accuracy that can be achieved when using the corresponding DL-PRS configuration.

[0203] The first subset may have PRS resources that may be sent at a low periodicity value (e.g., 5 transmissions per subframe), while the second subset may have PRS resources that may be sent at a higher periodicity value (e.g., 20 transmissions per subframe). Before selecting the DL-PRS configuration, the WTRU may perform measurements on the first subset (e.g., in this case) to determine the quality of the radio conditions (e.g., RSRP) and / or the positioning information of the WTRU. The WTRU may (e.g., may then) determine whether to perform measurements on the second subset based on whether the determined quality of the radio conditions is satisfactory (e.g., RSRP is greater than / less than one or more thresholds) and / or whether the determined accuracy of the WTRU positioning information is satisfactory (e.g., the error relative to the information determined via the estimation mode is less than / greater than one or more thresholds).

[0204] A WTRU in low power operation (e.g., INACTIVE / IDLE state / mode / operation) may detect the PCI / cell ID from the SIB. The WTRU may receive information about the first subset (e.g., ID, resources) from the SIB or preconfiguration based on the association between the PCI and the first subset (e.g., which may be indicated in the SIB or other DL message / signaling (e.g., LPP, AS layer)). The WTRU may perform initial measurements using resources in the first subset associated with one or more cells / TRPs. When the determined RSRP of the measurements associated with one or more cells / TRPs is greater than a threshold, the WTRU may perform measurements using resources in the second subset to determine positioning information. The measurements in the second subset may be intended to achieve higher positioning accuracy at the current or future location and / or time (e.g., using prediction / extrapolation). The measurements in the second subset may be intended to compensate for the low accuracy achieved in previous locations and / or time instances (e.g., using smoothing / interpolation).

[0205] When the measured determined RSRP associated with one or more cells / TRPs is less than a threshold, the WTRU may supplement / compensate for the insufficient measurements with estimates made by operating in an estimation mode (e.g., sensor measurement, trajectory tracking, prediction). The WTRU may transmit an indication / report to the network based on one or more of: a selection of a first subset of resources and / or a subset of parameters and / or a second subset of resources and / or parameters to be applied for measurement; an applied operating mode (measurement / estimation mode); timing information (e.g., timestamp) indicating when the first subset and / or the second subset is applied; or an error / precision determined when using the first subset / second subset.

[0206] An example of a WTRU using a DL-based positioning configuration based on TRS reception is provided herein. The WTRU may determine the DL-PRS configuration to be applied based on the reception and / or measurement of a tracking reference signal (TRS), possibly during LPHAP (e.g., operation in measurement mode and / or estimation mode). TRS for time-frequency synchronization may be implemented using a sparsely configured CSI-RS having a sparse set of resources / symbols. When operating in a power saving mode (e.g., during an off duration during an INACTIVE / IDLE state), the WTRU may periodically wake up to measure the presence of DL signals (e.g., primary synchronization signal (PSS), secondary synchronization signal (SSS), SSB, paging signal, wake-up signal / indication) (e.g., possibly for maintaining synchronization with the network). Such a process may be performed before the WTRU may be able to receive DL-PRS for positioning measurements. However, waking up (e.g., waking up periodically) to detect / decode DL signals may result in (e.g., additional) power consumption and higher latency.

[0207] A WTRU in a power saving mode (e.g., in low power operation or in an INACTIVE state / mode / operation) may receive a TRS for performing time-frequency synchronization with the network prior to receiving a DL-PRS for measurement. The WTRU may be configured with DRX in a power saving mode. The WTRU may receive a TRS prior to an on-duration or a paging occasion (e.g., with an offset duration configured relative to the on-duration). The WTRU may perform PRS measurements (e.g., after quickly ensuring that synchronization is maintained or re-established based on the TRS measurements). For example, the WTRU may perform PRS measurements without incurring delays (e.g., additional delays) associated with sending, receiving and / or processing other signaling and measurements.

[0208] The PRS configuration that may be selected / applied by the WTRU for positioning measurements may depend on the type of TRS available (e.g., different types of CSI-RS) and / or the quality of the TRS measurements. Depending on the type of PRS configuration that the WTRU intends to use for positioning, the WTRU may determine (e.g., in this case) whether TRS may be used to achieve synchronization with the base station / gNB / TRP. For using a PRS configuration with a low bandwidth, the WTRU may perform an initial synchronization with the TRS, while for using a PRS configuration with a wide bandwidth (e.g., for high accuracy), the WTRU may perform synchronization with the SSB.

[0209] To support TRS-based selection of a PRS configuration, the WTRU may receive association and / or assistance information indicating a combination of associations and / or mapping relationships between one or more DL-PRS configurations, TRS configurations, thresholds for TRS-based selection of a PRS configuration, the mobility state of the WTRU, positioning areas (e.g., cell / TRP / gNB) or reference locations and / or time instances. Such association information may be received by the WTRU via SIB, LPP signaling, or AS layer signaling (e.g., RRC, MAC CE, DCI, PDSCH, etc.) when operating in different RRC states. The association information may be received by the WTRU via a paging message, an on-demand SIB, or an on-demand PRS message. The association and / or assistance information may (e.g., may also) indicate that the WTRU may expect to receive the PRS after a certain number of time slots / symbols after receiving the TRS. For different associations between the TRS configuration and the PRS configuration, the number of time slots / symbols that the WTRU may expect to receive the PRS after receiving the TRS may vary.

[0210] A positioning area may be associated with one or more TRS configurations on a per-cell / TRP / gNB basis. Different TRS configurations may (e.g., may also) be associated with one or more PRS configurations with different bandwidths / resources. A WTRU in a positioning area may determine the PRS configuration to apply for positioning based on measurements made on the associated TRS.

[0211] An example of a WTRU performing WTRU location prediction to compensate for reduced DL measurements is provided herein. When operating in a power saving mode (e.g., INACTIVE / IDLE state / mode / operation), the WTRU may compensate for the lack of measurement information by transmitting to the network a report of predicted WTRU location information determined by operating in an estimation mode. In an example, the WTRU may receive configuration information and / or assistance data. The configuration information and / or assistance data may include at least one of: trajectory information (e.g., a straight path, a left curve, a right curve, or a parameter describing the motion / movement of the WTRU); timing information for prediction / smoothing (e.g., a scheduled time opportunity (e.g., T0, T1, T2, ...), a prediction interval (D1) for determining a future WTRU location, and a smoothing interval (D2) for determining an intermediate WTRU location); one or more thresholds associated with a prediction error (e.g., a difference between an actual location and a predicted / estimated location); or may include a reporting configuration of a time opportunity at which the WTRU is expected to transmit positioning information to the network.

[0212] The WTRU may transmit information about an initial trajectory (e.g., movement in a straight path). The WTRU may receive a PRS configuration and / or resources associated with the reported trajectory, which may be applied during measurement mode and / or estimation mode. At a first time instance (e.g., T0), the WTRU may perform PRS measurements using the received PRS configuration and / or resources. The WTRU may perform predictions of the WTRU position at different prediction intervals (D1) up to a second time instance (e.g., T1) based on operation in estimation mode and / or trajectory information. At a second time instance (e.g., T1), the WTRU may perform PRS measurements using the received PRS configuration. The WTRU may determine an actual WTRU position at the second time instance based on the measurements. The WTRU may (e.g., may then) determine a prediction error (e.g., a difference between the actual WTRU position and the estimated WTRU position at T1). When the prediction error is less than a first threshold, the WTRU may determine the WTRU position information in an intermediate instance and / or a position of a smoothed interval between the first time instance and the second time instance (e.g., possibly using a smoothing / interpolation technique). The WTRU may transmit an estimated WTRU position in a smoothing interval between a first time occasion and a second time occasion (e.g., in a subsequent reporting occasion). The WTRU may transmit the estimated / predicted WTRU position, possibly upon detecting another triggering event (e.g., a WTRU trajectory change or a mobility state change). When the prediction error is greater than a first threshold and / or less than a second threshold, the WTRU may apply certain adjustments to the prediction / smoothing model applied in the estimation mode and / or may perform corrections on the estimated WTRU position and / or position in the intermediate instance to determine corrected WTRU position information. The WTRU may (e.g., may then) transmit the corrected estimated WTRU position information to the network. When the prediction error is greater than a second threshold, the WTRU may transmit the actual position information determined at the second time occasion via measurement of the DL-PRS. The WTRU may (e.g., may also) transmit an indication to request an updated configuration and / or assistance data of timing information (e.g., new timing information) and / or PRS configuration (e.g., an updated PRS configuration with high bandwidth, high density) for prediction / smoothing.

[0213] The WTRU may determine a mode for reporting measurements in low power operation (e.g., INACTIVE / IDLE state / mode / operation). For example, when performing DL-based positioning in the INACTIVE / IDLE state, the WTRU may determine what to include in the measurement report and / or how to transmit the measurement report (e.g., this may potentially minimize the number / amount of transmissions and / or improve power saving of the LPHAP at the WTRU). When operating in the INACTIVE / IDLE state, the WTRU may be configured to perform DL-PRS measurements using one or more of the following reporting modes when transmitting measurement reports to the network: staggered measurements, skip or resume reporting, differential reporting, or discarded measurements.

[0214] For staggered measurements, the WTRU may be configured to perform RSRP / RSTD measurements of PRS received over one or more time periods / opportunities. The WTRU may stagger one or more measurements over M occasions before sending the measurements. In an example, the number M of occasions for staggered measurements may be preconfigured in the WTRU. In an example, the number M of occasions for staggered measurements may be determined by the WTRU based on one or more factors including: expiration of a timer, or an increase / decrease in RSRP / RSTD measurements relative to a previous / reference measurement.

[0215] For skipping or resuming reporting, the WTRU may (e.g., in the case where the WTRU is configured to perform measurements of DL-PRS) decide to skip transmitting one or more measurement reports (e.g., in the case where the change in the measurements made relative to the previous / reference measurement is below a threshold (e.g., RSTD / RSRP difference threshold). The WTRU may resume transmitting measurement reports when the change in the measurements made relative to the previous / reference measurement is above the threshold.

[0216] For differential reporting, the WTRU may (e.g., where the WTRU is configured to report PRS measurements and / or position estimates) report differences or variations relative to a reference position and / or reference time instance. The reference position may correspond to the position of the WTRU at an earlier time instance or the position of a landmark / anchor point. The reference time instance may correspond to a start time instance, an initialization time instance, or a trigger time instance tracked by the WTRU. When performing differential reporting, the WTRU may report to the network information about a reference point / time (e.g., an ID or location of a reference point) and / or differences relative to the position and / or measurements taken / expected at the reference point / time.

[0217] For discarded measurements, the WTRU may discard one or more measurements or estimates if one or more of the following conditions are met: a configured timer expires, the report has a low priority, a positioning error is detected, the positioning accuracy decreases, the battery capacity decreases (e.g., below a threshold), or the Tx power used to send the report increases.

[0218] When transmitting a measurement report after performing DL-based positioning in low power operation (e.g., INACTIVE / IDLE state / mode / operation), the WTRU may include a timestamp indicating one or more of the following: the timing corresponding to when the measurement or estimation was made or the timing corresponding to the switch between one reporting mode and another.

[0219] When operating in low power operation (e.g., INACTIVE state / mode / operation), the WTRU may transmit positioning information to the network. A WTRU in an INACTIVE state may determine whether to send or skip reporting positioning information to the network based on a determined prediction error. In an example, the WTRU may be configured to perform at least one of the following. The WTRU may receive configuration information from the network (e.g., in an RRCRelease message). The configuration information may include one or more PRS configurations, time occasions (e.g., T1, T2) for transmitting positioning reports, and / or prediction error thresholds (e.g., the difference between the actual location and the predicted location). The WTRU may receive mobility attributes of the WTRU (e.g., WTRU speed and / or moving direction) from higher layers. The WTRU may perform a first PRS measurement at a first time occasion (T1) and determine the WTRU location at T1. The WTRU may determine a predicted WTRU location at a second time occasion based on the determined first WTRU location and the mobility attributes. The WTRU may send a positioning report to the network, the positioning report including the WTRU location determined at T1 and the WTRU location predicted at T2. The WTRU may perform a second PRS measurement at a second time instance (T2) and determine the WTRU position at T2. The WTRU may determine a prediction error based on the determined WTRU position and the predicted WTRU position at T2. When the prediction error is less than a threshold, the WTRU may skip sending a positioning report at T2. When the prediction error is greater than the threshold, the WTRU may send a positioning report including the WTRU position determined at T2 to the network.

[0220] If in low power operation (e.g., operating in an INACTIVE state / mode), the WTRU may transmit an indication to the network to assist in the prediction of the WTRU's location. The WTRU in the INACTIVE state may determine whether to transmit an ACK indication or a measurement report to the network based on the determined prediction error. In an example, the WTRU may be configured to perform at least one of the following. The WTRU may receive configuration information from the network (e.g., in an RRCRelease message), the configuration information including one or more PRS configurations, time occasions (e.g., T1, T2) for transmitting a positioning report, and / or a prediction error threshold (e.g., the difference between the actual location and the predicted location). The WTRU may receive a first set of mobility attributes of the WTRU (e.g., WTRU speed and / or moving direction) from a higher layer. The WTRU may perform a first PRS measurement at a first time occasion (T1) and determine the WTRU location at T1. The WTRU may send a positioning report to the network, the positioning report including the WTRU location determined at T1 and the first set of mobility attributes. The WTRU may receive a predicted WTRU location at T2 from the network. The WTRU may receive a second set of mobility attributes of the WTRU (e.g., WTRU speed and / or moving direction) from higher layers. The WTRU may perform a second PRS measurement at a second time opportunity (T2) and determine the WTRU position at T2. The WTRU may determine a prediction error based on the determined WTRU position and the predicted WTRU position at T2. When the prediction error is less than a threshold, the WTRU may send an ACK message to the network (e.g., to indicate that the prediction at the network is valid). When the prediction error is greater than the threshold, the WTRU may send a positioning report to the network, the positioning report including the WTRU position determined at T2 and the second set of mobility attributes (e.g., any one of them).

[0221] Examples are provided herein for supporting UL-based LPHAP. The WTRU may send UL-SRSp transmissions for LPHAP based on the UL configured positioning area. When operating in a power saving mode during mobility, the WTRU may use one or more SRSp configurations and / or resources (e.g., periodic, non-periodic, semi-persistent) to send SRSp, which may be applied to different UL configured positioning areas. The UL configured positioning area may include one or more cells / TRPs / gNBs, which may be configured to perform measurements on the SRSp sent by the WTRU. Different positioning areas that the WTRU may traverse based on the WTRU trajectory may be associated with different SRSp configurations. The WTRU may use resources from the SRSp configuration for SRSp transmissions based on the positioning area / valid area where the WTRU may be located. The SRSp configuration may (e.g., may also) be associated with a validity time or scheduling time, indicating when the WTRU may start / stop using the scheduling of the SRSp configuration for SRSp transmission.

[0222] An SRSp configuration may be associated with a positioning area and a scheduling time, which may (e.g., may also) be associated with a trajectory of the WTRU. The WTRU may receive a pre-configured SRSp configuration (e.g., in this case) from the network (e.g., a serving gNB). The WTRU may select an SRSp configuration from the pre-configuration based on the positioning area in which the WTRU may be located and / or the associated scheduling time. The WTRU may (e.g., may also) receive one or more SRSp configurations (e.g., which may be used for low power operation (e.g., power saving mode or during INACTIVE / IDLE state / mode / operation)), which may be associated with achieving different positioning QoS (e.g., based on the accuracy achievable by measurements made by the TRP / gNB) in different positioning areas and / or within the positioning area. A WTRU in a positioning area may select an SRSp configuration based on one or more of the following: an SRSp configuration that may be associated with a positioning area, a sub-area within a positioning area, or an expected level of positioning accuracy to be achieved.

[0223] To determine the positioning area / sub-area in which the WTRU may be located, the WTRU may (e.g., initially) receive / detect the IDs of one or more cells / TRPs / gNBs (e.g., which may be in the vicinity of the WTRU and associated with the positioning area) via SIB / SSB / PBCH. The WTRU may estimate the WTRU location and determine the corresponding positioning area and the associated SRSp configuration to be applied based on operation in estimation mode (e.g., prediction, sensor measurement, tracking trajectory, etc.). If the accuracy / error of the WTRU location in the positioning area determined based on the estimation mode operation is greater than / less than one or more thresholds, the WTRU may determine the SRSp configuration to be applied.

[0224] In order to determine whether the expected positioning QoS level can be achieved using the SRSp sent by the WTRU and / or the measurements made by the corresponding TRP / gNB, the WTRU may perform measurements of DL signals (e.g., DL-PRS, CSI-RS, SSB, TRS, RS associated with the SRSp space / QCL). The measurements of the DL signals may determine the quality of the radio link corresponding to one or more TRP / gNBs associated with the positioning area in which the WTRU may be located (e.g., RSRP measurement, number of multipaths, LOS / NLOS indication). The association / assistance information related to the DL signal may be received by the WTRU in SIB, LPP signaling, or AS layer signaling (e.g., RRC, MAC CE, DCI). The association / assistance information may be related to the SRSp space and / or sent from the TRP / gNB to which the WTRU intends to send the SRSp. The WTRU may select the SRSp configuration based on the quality of the radio link. When the RSRP of the corresponding DL signal (e.g., which may be measured by the WTRU) is greater than a threshold, the WTRU may select a low bandwidth SRSp configuration. When the RSRP of the corresponding DL signal (eg, which may be measured by the WTRU) is less than a threshold, the WTRU may select a high bandwidth SRSp configuration. Selecting different SRSp configurations based on the quality of the associated DL signal may enable different and / or consistent levels of positioning accuracy to be achieved during SRSp transmission.

[0225] The WTRU may determine, based on operations in an estimation mode (e.g., predictions, sensor measurements, tracking trajectories, etc.), an SRSp configuration to be applied to achieve an expected positioning QoS level. The WTRU may use a low-bandwidth, low-periodicity SRSp configuration to send SRSp in the UL. The WTRU may (e.g., may then) determine the accuracy / error of the WTRU position (e.g., determined using the estimation mode) based on an indication received from the network (e.g., in an LPP message, paging, RRC message, MAC CE, DCI, etc.), which may indicate information about the WTRU position determined via SRSp measurements in the network. The WTRU may (e.g., may then) determine a high-bandwidth, high-periodicity SRSp configuration for sending SRSp and / or for achieving a positioning accuracy level. The WTRU may (e.g., may then) determine a high-bandwidth, high-periodicity SRSp configuration based on whether the error / accuracy achieved using the low-bandwidth, low-periodicity SRSp configuration is greater than or less than one or more thresholds.

[0226] The WTRU may (e.g., may also) change the SRSp configuration to be applied based on a change in the WTRU mobility state (e.g., from stationary to a first (low) speed level, from a first speed level to a second speed level). When changing from a static mobility state to a low speed mobility state, the WTRU may use a first SRSp configuration (e.g., a high periodicity SRSp configuration) to determine (e.g., ensure) that the WTRU position can be determined with high accuracy when measuring the SRSp sent by the WTRU at the network. When the mobility state remains stable (e.g., within a speed range or within one or more thresholds), the WTRU may use a second SRSp configuration (e.g., a low periodicity SRSp configuration). The WTRU may use the second SRSp configuration to maintain a level of positioning accuracy and / or power savings. When changing from a first SRSp configuration to a second SRSp configuration, the WTRU may transmit an indication to the network (e.g., in an LPP message, RRC, MAC CE, UCI, etc.) to activate the measurement of the SRSp sent by the WTRU.

[0227] An example of a WTRU performing UL-based LPHAP based on location-dependent configurations and / or resources is provided herein. The WTRU may determine SRSp resources for performing SRSp transmission (e.g., based on location-dependent configurations / resources for UL positioning). The SRSp configurations and / or resources accessed by the WTRU may be associated with one or more positioning areas. A positioning area (e.g., each positioning area) may include one or more cells / TRPs / gNBs. The WTRU may use one or more SRSp configurations (e.g., periodic, aperiodic, semi-persistent) when located within an associated positioning area and / or when at least one TRP / gNB is detected in the positioning area (e.g., a PCI / cell ID is received and / or the RSRP of the radio link is above a threshold). The location-dependent SRSp configuration for LPHAP, including resource sets and resource subsets intended for activation / deactivation of the SRSp configuration, may be received by the WTRU in one or more of the following: RRC CONNECTED state; RRC release message (e.g., in a SuspendConfig message), SDT DL message; SIB or paging message.

[0228] For the RRC CONNECTED state, if in the CONNECTED state and / or if transitioning to low power operation (e.g., INACTIVE / IDLE state), the WTRU may receive an SRSp configuration when transmitting a request for positioning services to the serving gNB (e.g., via an LPP / LCS request or an RRC request). The WTRU may receive information about the positioning areas in which the SRSp configuration may be valid. The received SRSp configuration may be stored by the WTRU and used to detect the associated positioning areas. For an RRCRelease message (e.g., in a SuspendConfig message), the WTRU may receive an SRSp configuration if the WTRU is released to low power operation (e.g., INACTIVE or IDLE state). The SDT DL message may include a DL RRC message that may use DL-SDT random access resources associated with the SDT (e.g., in Msg B when a 2-step RACH procedure is used, or in Msg 4 when a 4-step RACH procedure is used). The SIB may include a SIB broadcast message (e.g., posSIB). A paging message may be received by the WTRU from one or more TRPs / gNBs in the positioning area (e.g., together with a WTRU ID).

[0229] The WTRU may receive one or more validity conditions and / or events associated with the SRSp (e.g., in addition to the SRSp configuration) to indicate whether the received and / or stored SRSp configuration is valid and / or when / where the SRSp configuration may be used / released. The validity conditions and / or events associated with the SRSp configuration may include one or more of: a timer, a RSRP change, or a validity region.

[0230] For timers, a timer (e.g., a TA timer) may be associated with a cell / TRP or a positioning area (e.g., including multiple cells / TRPs). A timer may be used to indicate when an SRSp configuration may be activated / deactivated. When a TA timer is configured and / or set (e.g., when under coverage of a cell and / or positioning area), a WTRU pre-configured with an SRSp configuration may activate the SRSp configuration for sending SRSp. When the TA timer expires, the WTRU may deactivate SRSp sending. The WTRU may retain the SRSp configuration without releasing it for subsequent use, or release the SRSp configuration when the TA timer expires, which may be based on an explicit indication received from the network or an implicit indication detected (e.g., via the duration configured for the TA timer).

[0231] For RSRP changes, if the RSRP measured on the DL signals (e.g., RS) received from one or more TRPs in the positioning area (e.g., which may be spatially related to the SRSp) is less than or greater than one or more thresholds, the WTRU may activate / deactivate / release the SRSp configuration. In the example: i) when the RSRP is less than a first threshold, the WTRU may activate the SRSp configuration; ii) when the RSRP is greater than the first threshold and less than a second threshold, the WTRU may deactivate the SRSp configuration; and iii) when the RSRP is greater than the second threshold, the WTRU may release the SRSp configuration.

[0232] For the valid area, the WTRU may activate / deactivate / release the SRSp configuration when entering / leaving a positioning area covered by one or more cells / TRPs / gNBs. The WTRU may activate the SRSp configuration when a first TRP is detected in the positioning area, and may deactivate / release the SRSp configuration when a second TRP is detected in the same / different positioning area.

[0233] The WTRU may receive the SRSp configuration from a serving gNB (e.g., after establishing an RRC connection) or may receive the SRSp configuration from a non-serving gNB (e.g., without establishing an RRC connection) using any of the methods discussed herein. In the case of a non-serving gNB (which may be located in a positioning area where the WTRU may be located), the WTRU may indicate a request for SRSp configuration and / or resources by transmitting a RACH message / preamble associated with the request. A WTRU (e.g., a WTRU pre-configured with one or more SRSp configurations) may transmit a request for activating / deactivating SRSp by transmitting a RACH message / preamble associated with an activation request (e.g., together with a WTRU ID and / or SRSp configuration ID).

[0234] Examples of WTRUs using common SRSp resources based on sensing are provided herein. Location-dependent SRSp configurations and / or resources may not be dedicated to a given WTRU and / or may be common to multiple WTRUs located in a positioning area. This may cause interference when multiple WTRUs (e.g., which may be located nearby) use common SRSp resources to send SRSp at the same time. The WTRU may include (e.g., in this case) an identifier associated with the WTRU (e.g., preamble / WTRU ID / RA-RNTI) and / or a request to send SRSp in an UL message (e.g., RACH, RRC message transmitted in RACH-SDT) before sending SRSp using common SRSp resources.

[0235] If a DL indication (e.g., in a DL SDT) confirming / activating the SRSp resources and / or an identifier that may be associated with the WTRU is received from the network, the WTRU may use the common SRSp resources to send the SRSp. When sending the SRSp, the WTRU may include and / or scramble the identifier associated with the WTRU. The WTRU may initiate a sensing procedure and / or a listen before talk (LBT) procedure to determine whether the common SRSp resources are currently being used by other WTRUs in the vicinity. In an example, the WTRU may perform sensing / LBT and / or measure the energy level (e.g., RSRP) on the SRSp resources for a configured duration. If the measured energy level (e.g., average, peak) is less than a threshold value during the sensing / LBT duration, the WTRU may use the SRSp resources for a certain duration (e.g., the channel occupancy time (COT) associated with the SRSp configuration). The WTRU may wait (e.g., may otherwise wait) for a certain duration (e.g., over a random number of time slots, a configured number of time slots) before re-initiating the sensing / LBT procedure for accessing the common SRSp resources.

[0236] The common SRSp resources may be accessed by the WTRU to determine (e.g., to ensure) a certain positioning accuracy achieved (e.g., in the case where the TRP / gNB performs measurements of the SRSp sent by the WTRU). Positioning accuracy levels (e.g., in this case) may be associated with different priority values, which may be used by the WTRU to access the common SRSp resources. The use of such priority values ​​may result in the use of SRSp resources with different COTs during SRSp transmissions. A WTRU that aims to achieve a high level of accuracy may access resources with a first priority (e.g., a high value) and / or use SRSp resources with a first COT (e.g., a long duration) during SRSp transmissions. A WTRU that aims to achieve a medium level of accuracy may access resources with a second priority (e.g., a low value) and / or use SRSp resources with a second COT (e.g., a short duration) during SRSp transmissions. The association between the SRSp resources, priority values ​​and / or COT values ​​may be received by the WTRU as auxiliary information / dynamic indication from the network (e.g., via LPP messages, RRC messages, SIBs, MAC CEs, DCIs, etc.).

[0237] An example of a WTRU changing / switching between SRSp configurations for supporting UL-based LPHAP based on detection of a triggering event is provided herein. The WTRU may change from using a first SRSp configuration (e.g., high periodicity) to a second SRSp configuration (e.g., low periodicity) based on detection of one or more triggering events / conditions (e.g., WTRU mobility state change, receipt of a DL indication, etc.).

[0238] Examples may include the following. The WTRU may receive configuration information including one or more SRSp configurations, the one or more SRSp configurations including at least resources in a first SRSp configuration (e.g., high periodicity, low Tx duration, high bandwidth) and a second SRSp configuration (e.g., low periodicity, high Tx duration, low bandwidth). The configuration information may include SRSp Tx opportunities (e.g., T0, T1, T2, ...) for sending SRSp, where each time opportunity (Ti) may be associated with the same or different SRSp configuration. In an example, T0 may be associated with the first SRSp configuration, and T1 may be associated with the second SRSp configuration. The configuration information may include an SRSp Tx update / interruption duration D. In an example, the Tx update duration may refer to a duration during which the WTRU may not perform the sending of an SRSp and / or may change from a first SRSp configuration to a second SRSp configuration.

[0239] The WTRU may receive configuration information if in the RRC CONNECTED state (e.g., as pre-configured), in the RRC INACTIVE state (e.g., via a RRCRelease message in SuspendConfig), or in the RRC IDLE state (e.g., via a RACH / initial access message, a paging message during an initial access procedure). Configurations received during the CONNECTED or INACTIVE state may be used and / or activated when operating in the INACTIVE and / or IDLE state. The WTRU may transition or may be transitioned by the network to the INACTIVE or IDLE state (e.g., after receiving configuration information when operating in the CONNECTED / INACTIVE state).

[0240] When a first triggering event for initiating SRSp transmission is detected (e.g., mobility state change, DL indication received), the WTRU may start a first timer (e.g., for a configured time period). The first timer may run for a duration spanning the next Tx opportunity - the current Tx opportunity (e.g., T1 to T0). When a first triggering event for initiating SRSp transmission is detected (e.g., mobility state change, DL indication received), the WTRU may select an SRSp configuration associated with the current SRSp Tx opportunity. In an example, when the current SRSp Tx opportunity is T0, the WTRU may select a first SRSp configuration (e.g., high periodicity), and when the current SRSp Tx opportunity is greater than T0, the WTRU may select a second SRSp configuration (e.g., low periodicity). When a first triggering event for initiating SRSp transmission is detected (e.g., mobility state change, DL indication received), when the current Tx opportunity is T0, the WTRU may transmit an indication to the network (e.g., gNB / base station) indicating the start of SRSp transmission. In an example, if the WTRU is in an INACTIVE state, the WTRU may transmit an indication in the SDT using RACH or CG resources associated with the SDT. In an example, when the WTRU is in an IDLE state, the WTRU may transmit an indication in an initial access / RACH message (e.g., an RRCRequest, an RRCSystemInformation request, an RRCReconfiguration request, or a RACH / RRC message associated with positioning). In an example, the WTRU may transmit an indication when in IDLE during a RACH opportunity (e.g., which may be associated with positioning). When transmitting an indication in INACTIVE / IDLE, the WTRU may include a flag / information and / or use resources associated with low-power positioning so that the WTRU may not be transitioned to a CONNECTED state. In an example, the WTRU may transmit an indication to the network when transitioning to a CONNECTED state, which may be due to non-positioning or positioning-related reasons.

[0241] When a first triggering event for initiating SRSp transmission is detected (e.g., mobility state change, receipt of DL indication), the WTRU may receive an indication from the network (e.g., in LPP, RRC, MAC CE, DCI, etc.), possibly confirming / activating the transmission of the SRSp using the selected SRSp configuration. In an example, if the WTRU is in INACTIVE (e.g., INACTIVE state / mode / operation), the WTRU may receive an indication in a DL-SDT message (e.g., via activated SDT configuration, DL-SDTRACH response, SPS-SDT, RRCRelease). In an example, if the WTRU is in IDLE (e.g., IDLE state / mode / operation), the WTRU may receive an indication in an RRC message (e.g., RRCSetup, RRCReconfiguration) or a RACH response message. In an example, the WTRU may receive an indication in an updated SIB, which may be accessed by the WTRU after a configured duration (e.g., expiration of a timer) when the indication is transmitted to the network. If a first triggering event for initiating SRSp transmission is detected (eg, mobility state change, receipt of a DL indication), the WTRU may send the SRSp using the resources in the selected SRSp configuration.

[0242] If a first triggering event for initiating SRSp transmission is detected (e.g., mobility state change, DL indication received) and if a second event is detected (e.g., mobility state change), the WTRU may stop the first timer and stop the transmission of SRSp. When the second event is detected, the WTRU may start a second timer for a duration D (e.g., for a configured time period). If the second event is a semi-static event (e.g., the WTRU receives periodic data in the DL) and / or the second event ends before the expiration of the second timer, the WTRU may restart the first timer and / or restart the transmission of SRSp using the current SRSp configuration (e.g., the SRSp configuration associated with the most recent SRSp Tx opportunity). If the second event is a dynamic event (e.g., high priority / URLLC data is received, trajectory / mobility state change) and / or the second event ends after the expiration of the second timer, the WTRU may reset the first timer (e.g., to T0). The WTRU may transmit an indication to the network indicating the reset of the timer and / or the start of SRSp transmission. The WTRU may (e.g., may then) send the SRSp using resources in the SRSp configuration associated with the Tx time opportunity (e.g., reset time T0). If the second event corresponds to suspending transmission (e.g., receiving a DL indication indicating to stop SRSp transmission), the WTRU may stop the first timer and stop sending SRSp. If the second event is not detected, the WTRU may stop sending SRSp when the first timer expires (e.g., possibly for a configured duration associated with the INACTIVE / IDLE time until the next Tx opportunity begins).

[0243] An example is provided herein of a WTRU sending an SRSp based on detecting a location in a preconfigured positioning area. The WTRU may use an SRSp configuration associated with a preconfigured positioning area to send an SRSp at one or more locations associated with the positioning area (e.g., the coverage area of ​​a TRP / gNB set). Based on the positioning area in which the WTRU may be located and the expected positioning QoS (e.g., accuracy) to be achieved using measurements at the TRPs in the positioning area, the WTRU may select an SRSp configuration from a set of preconfigured SRSp configurations. If the expected accuracy requirement cannot be met at the TRP, the WTRU may use a special SRSp configuration (e.g., a high BW SRSp configuration) associated with at least some TRPs that may meet the expected positioning QoS.

[0244] The WTRU may receive configuration information (e.g., in the RRC CONNECTED / INACTIVE / IDLE state), including one or more of the following: one or more SRSp configurations, including at least resources in a low-bandwidth SRSp configuration and a high-bandwidth SRSp configuration (e.g., a special SRSp configuration); scheduled time opportunities (e.g., T1, T2, ... Ti) at which the WTRU expects to send SRSp; one or more TRP sets (e.g., cell IDs) in the positioning area, where each TRP set may be associated with an SRSp configuration (e.g., the TRPs in the set may be configured by the LMF to measure the SRSp sent by the WTRU at different time opportunities); or a threshold for the minimum / maximum number of TRPs that may be required to meet the positioning accuracy requirement.

[0245] The WTRU may transition or may be transitioned by the network to operate in low power operation (e.g., INACTIVE / IDLE state / mode / operation) (e.g., after receiving configuration information). The WTRU may perform measurements on DL signals (e.g., TRS / SSB / PRS / CSI-RS) for detecting one or more TRPs and for determining radio conditions associated with the detected TRPs (e.g., RSRP measurements of RSs that may be spatially correlated with SRSp). The WTRU may perform measurements at least at the following time occasions: before Ti, near time Ti, at Ti.

[0246] If one or more detected TRPs match the configured TRP set (e.g., the count at which the ID of the detected TRP set and the ID of the configured TRP set are the same or differ by less than a threshold count), and if the number of detected TRPs with good RSRP (e.g., the measured RSRP is greater than an RSRP threshold) is greater than a threshold of a minimum number of TRPs, the WTRU may select a low-bandwidth SRSp configuration associated with the detected TRP. The WTRU may (e.g., may then) send the SRSp using resources in the low-bandwidth SRSp configuration at the scheduled time opportunity Ti. If one or more detected TRPs match the configured TRP set (e.g., the count at which the ID of the detected TRP set and the ID of the configured TRP set are the same or differ by less than a threshold count), and if the number of detected TRPs with good RSRP is less than a threshold of a minimum number of TRPs, the WTRU may determine a high-bandwidth SRSp configuration (e.g., a special SRSp configuration) associated with the detected TRP with good RSRP (e.g., possibly based on receiving a positioning SIB or pre-configured in the WTRU). The WTRU may transmit an indication to the gNB (e.g., when operating in the RRC INACTIVE state, the WTRU may transmit the indication via RACH-SDT / CG-SDT, and when operating in the RRC IDLE state, the WTRU may transmit the indication via RACH / initial access message / RRCRequest or on a RACH opportunity associated with a positioning message) indicating the ID of the detected TRP. The WTRU may request activation of the high-bandwidth SRSp configuration. The WTRU may send the SRSp using resources in the high-bandwidth SRSp configuration (e.g., possibly after receiving an activation indication from the gNB). In an example, when operating in the INACTIVE state, the WTRU may receive an indication from the network in a DL-SDT message. In an example, when operating in the IDLE state, the WTRU may receive an indication in a RACH response / RRCSetup / SIB update message.

[0247] If the detected TRP does not match the configured TRP set (e.g., the count where the ID of the detected TRP set and the ID of the configured TRP set differ by more than a threshold count), the WTRU may transmit an indication to the gNB to request an updated SRSp configuration. The WTRU may send the updated SRSp using resources in the updated SRSp configuration (e.g., after receiving information about the updated SRSp configuration from the gNB).

[0248] An example of a WTRU sending an SRSp based on detecting a Tx scheduled time opportunity and a triggering event is provided herein. The WTRU may send an SRSp at a scheduled time opportunity using the SRSp configuration associated with the time opportunity. The duration difference between each time opportunity may be an absolute preconfigured value or a variable relative value (e.g., in this case), which may depend on the previous time opportunity and / or the type of event detected by the WTRU. When an event is detected (e.g., the WTRU deviates from the expected trajectory, or the measurement of the spatially correlated RS is below the RSRP threshold), the WTRU may use an alternative SRSp configuration to improve accuracy.

[0249] Examples may include the following. The WTRU may receive configuration information including one or more of the following: one or more SRSp configurations, including at least resources in a low-bandwidth SRSp configuration and a high-bandwidth SRSp configuration (e.g., high BW and / or non-continuous to achieve high accuracy); a scheduled time opportunity (e.g., T0, T1, T2, ...) at which the WTRU may be expected to send an SRSp; or a SRSp Tx duration D.

[0250] At a scheduled time opportunity (e.g., a first scheduled time opportunity (e.g., T0)), the WTRU may send SRSp using resources from the low-bandwidth SRSp configuration. When the WTRU detects a triggering event (e.g., the WTRU receives a low-precision indication from the network, there is a change in mobility state or trajectory), the WTRU may stop SRSp transmission using the low-bandwidth SRSp configuration and / or start a timer that may run for a duration D. The WTRU may transmit an indication to the network (e.g., gNB, LMF) requesting activation of the high-bandwidth SRSp configuration. The WTRU may send SRSp using resources from the high-bandwidth SRSp configuration until the timer expires (e.g., after receiving an activation / confirmation message from the network).

[0251] If the triggering event ends before the timer expires, the WTRU may stop SRSp transmission using the high-bandwidth SRSp configuration at the end of the event. If the triggering event ends after the timer expires and / or before the second scheduled time opportunity (e.g., T1) starts, the WTRU may stop SRSp transmission using the high-bandwidth SRSp configuration at the expiration of the timer. If the triggering event ends after the start of the subsequent scheduled time opportunity (e.g., after T1), the WTRU may stop SRSp transmission using the high-bandwidth SRSp configuration at the expiration of the timer. The WTRU may start SRSp transmission using the high-bandwidth SRSp configuration at the start of the second scheduled time opportunity (e.g., T1). The WTRU may (e.g., may also) start a timer with a duration of D. When the event ends and / or when the timer expires, the WTRU may stop SRSp transmission using the high-bandwidth SRSp configuration. The WTRU may restart SRSp transmission using resources from the low-bandwidth SRSp configuration until the timer expires (e.g., in the case where the event ends before the timer expires). If no triggering event is detected, the WTRU may stop SRSp transmission using the low bandwidth SRSp configuration at the end of the SRSp Tx duration D.

[0252] Over time (e.g., for time opportunities greater than Tn, where n>0), the WTRU may gradually reduce the density of time / frequency resources in the SRSp configuration during SRSp transmission. The WTRU (e.g., in this case) may receive scheduled Tx time opportunities (e.g., T0, T1, T2) for SRSp transmission and / or the SRSp configuration associated with each timing. The WTRU may start the timer at the first Tx time opportunity. When an event is detected (e.g., the WTRU receives a DL signal / indication between T0 and T1), the WTRU may reset the timer (e.g., to T0) when the processing duration for processing the event (e.g., associated with the received DL signal / indication) is greater than a threshold. When the processing duration for processing the event is less than a threshold, the WTRU (e.g., on the other hand) may continue to transmit at the next Tx time opportunity. The WTRU may be configured with an SRSp transmission mode (e.g., SRSp transmission at a preconfigured timing and preconfigured time and / or frequency density). The WTRU may (e.g., may also) be configured with a time window (e.g., configured with start / end time, duration) from the network (e.g., LMF, gNB) during which the WTRU sends a pre-configured SRSp transmission.

[0253] If there is a dynamic event that may cause the WTRU to stop SRSp transmission (e.g., cancellation of SRSp transmission by DCI, MAC-CE, event that the WTRU cannot send SRSp scheduling), the WTRU may suspend SRSp transmission and restart transmission after the event (e.g., in the case where the WTRU is configured to send SRSp with time density or periodicity N1 during the initial transmission and send SRSp with time density or periodicity N2 after the initial transmission). The WTRU may send (e.g., after restarting) SRSp with density N1. If the WTRU is preconfigured with an SRSp transmission mode, the WTRU may determine to restart the transmission mode or continue to send SRSp after the event based on at least one of the following conditions (for example, the WTRU may be configured to send SRSp at a time density N1 during the initial transmission and at a time density N2 after the initial transmission, and if the event occurs after the initial transmission, the WTRU may determine to send SRSp at a density N2 after the event): (i) if the duration of the dynamic event is greater than a threshold duration, the WTRU may restart the transmission mode (for example, if the duration is less than or equal to the threshold duration, the WTRU may continue to send after the event); or (ii) if the event is semi-static (for example, periodic reception of DL / UL signals, monitoring of SSBs and / or DL ​​signals / channels, events configured by RRC or LPP, etc.), the WTRU may continue to send.

[0254] The WTRU may determine to terminate transmission at the end of the configured time window. The WTRU may receive the configuration from the network via DCI, MAC-CE, RRC or LPP message. If the WTRU is configured to transition from RRC_INACTIVE mode to RRC_CONNECTED, the WTRU may terminate SRSp transmission.

[0255] The WTRU may select a positioning area specific SRSp configuration based on the positioning area in which the WTRU is located. A WTRU in an INACTIVE state (e.g., INACTIVE operation) may select a positioning area specific SRSp configuration for performing SRSp transmission based on a cell associated with the positioning area in which the WTRU is located (e.g., based on a cell ID detected by the WTRU). If the WTRU is located in a cell associated with a first positioning area (e.g., a default positioning area), the WTRU may use the SRSp configuration of the first positioning area (e.g., the default SRSp configuration) to transmit the SRSp. If the WTRU is located in a cell outside the first positioning area (e.g., outside the default positioning area), the WTRU may transmit a request to the network to activate a pre-configured SRSp configuration associated with a positioning area outside the first positioning area (e.g., a second positioning area).

[0256] In an example, the WTRU may be configured to perform at least one of the following. The WTRU may receive configuration information, for example, from a base station in a first cell (e.g., in an RRCReconfig message when the WTRU is in an RRC CONNECTED operation / state, or in an RRCRelease message when the WTRU is in low power operation (e.g., INACTIVE operation / state or idle operation / state) or transitions from CONNECTED to INACTIVE). The configuration information may indicate different SRSp configurations associated with different positioning areas, such as a first SRSp configuration for a first positioning area and a second SRSp configuration for a second positioning area. The configuration information may indicate different cell ID sets associated with different positioning areas, such as a first cell ID set for a first positioning area and a second cell ID set for a second positioning area. The WTRU may send a first SRSp using a first (e.g., default) SRSp configuration (e.g., performed during low power operation (e.g., based on receiving an RRCRelease message) and before detecting a second cell). The WTRU may send a first SRSp using the first SRSp configuration based on detecting a cell ID in the first cell ID set. The WTRU may select (e.g., detect) a second cell. The WTRU may determine the positioning area in which the WTRU is located (e.g., based on the received / determined cell ID associated with the second cell). If the detected second cell ID is in the first (e.g., default) positioning area, the WTRU may send the SRSp using the first (e.g., default) SRSp configuration (e.g., in the second cell). If the detected second cell ID is not in the first (e.g., default) positioning area, the WTRU may determine the second positioning area in which the WTRU is located based on the detected second cell ID being in the second cell ID set and the second cell ID set being associated with (e.g., included in) the second positioning area (e.g., determined from the configuration information / first association information). The WTRU may determine the SRSp configuration to be used in the second positioning area (e.g., the second SRSp configuration) based on the SRSp configuration associated with the second positioning area (e.g., determined from the configuration information / second association information) (e.g., based on the determination that the WTRU is in the second positioning area). The WTRU may send an indication to the second cell to request activation of the SRSp configuration associated with the second positioning area (e.g., the second SRSp configuration). The WTRU may receive from the second cell an activation indication for a requested (e.g., second) SRSp configuration (e.g., indicating an ID of the SRSp configuration to be activated), a third SRSp configuration (e.g., different from the requested second SRSp configuration), or an activation indication for a third SRS configuration (e.g., in an RRCResume message, an RRCReconfig message, or a MAC CE).The WTRU may send the SRSp using the SRSp configuration activated or indicated by the second cell.

[0257] The configuration information received from the base station may include at least one of the following. The configuration information may include a first (e.g., default) SRSp configuration associated with a first positioning area (e.g., which may be activated). The configuration information may include a set of one or more SRSp configurations for positioning areas other than the first positioning area (e.g., the configuration information may include an SRSp configuration for a second positioning area, another SRSp configuration for a third positioning area, etc.). The configurations in the set of one or more SRSp configurations may be deactivated (e.g., at a time associated with the reception of the configuration information). The configuration information may include a first (e.g., default) positioning area (e.g., which may be, may include, or may be associated with an area ID) (e.g., associated with a first SRSp configuration) and a first set of cell IDs in the first (e.g., default) positioning area (e.g., cell IDs of cells in the first positioning area). The configuration information may include first association information indicating an association between a positioning area (e.g., which may be, may include, or may be associated with an area ID) and a set of cell IDs (e.g., which may include a second set of cell IDs associated with a second positioning area). The configuration information may include second association information indicating an association between a positioning area (e.g., which may be, may include, or may be associated with an area ID) and an SRSp configuration (e.g., which may be, may include, or may be associated with a configuration ID) (e.g., which may include a second positioning area associated with a second SRSp configuration).

[0258] For the WTRU to select the second cell, when the WTRU moves from the first cell to the second cell, the WTRU may (re)select the second cell (eg, when the WTRU detects the cell ID of the second cell, the WTRU may select the second cell).

[0259] For the WTRU to determine that the WTRU is located in a positioning area (e.g., a positioning area in which a second cell is located), the WTRU may determine the positioning area based on a second cell ID (e.g., PCI) detected in an SSB received from the second cell. In an example, the WTRU may determine that the second cell is located in the second positioning area based on the detected second cell ID being in a second set of cell IDs associated with the second positioning area.

[0260] For the WTRU to send an indication to the second cell regarding a request to activate an SRSp configuration associated with a second positioning area (e.g., the second SRSp configuration) (e.g., in the case where the detected second cell ID is not in the default positioning area), the WTRU may send the indication in an RRCResumeRequest message using SDT resources (e.g., RACH-SDT, CG-SDT). The ResumeRequest message may include a cause value / indication indicating a request to activate the SRSp configuration without transitioning to the CONNECTED state. For the WTRU to send an indication to the second cell regarding a request to activate an SRSp configuration associated with a second positioning area (e.g., in the case where the detected second cell ID is not in the default positioning area), the WTRU may transmit the ID of the SRSp configuration associated with the positioning area (e.g., the second positioning area) in which the WTRU may be located. The WTRU may send a request to deactivate the first (e.g., default) SRSp configuration in this indication or in another indication.

[0261] Figure 2 A WTRU in low power operation (e.g., INACTIVE state) is illustrated selecting a location area specific SRSp configuration for performing SRSp transmissions. The WTRU may select a location area specific SRSp configuration for performing SRSp transmissions based on a cell associated with the location area in which the WTRU is located (e.g., based on a cell ID detected by the WTRU). For example, if the WTRU is located in a cell (e.g., cell 2) associated with a first (e.g., default) location area or performs cell (re)selection in that cell, the WTRU may use a first (e.g., default) SRSp configuration to send SRSp transmissions. For example, if the WTRU is located in a cell (e.g., cell 4) outside the default location area or performs cell (re)selection in that cell, the WTRU may transmit a request to the network to activate a second SRSp configuration associated with a second location area (e.g., preconfigured).

[0262] The WTRU may transmit a request to update the validity condition of the SRSp configuration. When a configured positioning event is detected (e.g., an updated cell ID is detected due to cell reselection or mobility), the WTRU in low power operation (e.g., INACTIVE state) may transmit an indication to the network to update the validity condition associated with the SRSp configuration (e.g., TA timer). In an example, the WTRU may be configured to perform at least one of the following. The WTRU may receive configuration information (e.g., in an RRCRelease message) that includes at least one of an SRSp configuration (e.g., a first SRSp configuration), a validity condition (e.g., a TA timer associated with the SRSp configuration), or a positioning event (e.g., detection of an updated cell / TRP ID). The WTRU may send the SRSp using the SRSp configuration (e.g., the first SRSp configuration). If the validity condition has not expired when an updated TRP / cell ID is detected (e.g., outside the positioning area), the WTRU may transmit an indication to the gNB indicating a request to extend the validity condition (e.g., in an RRC message or MAC CE using SDT resources), receive an indication from the gNB indicating an extension of the validity condition (e.g., in an RRC message or DL ​​MAC CE), and / or send an SRSp using an SRSp configuration (e.g., a second SRSp configuration) in an existing and / or updated cell. If the validity condition expires when an updated TRP / cell ID is detected (e.g., outside the positioning area), the WTRU may release the SRSp configuration (e.g., a first SRSp configuration), transmit an indication to the gNB indicating a request for an updated (e.g., second) SRSp configuration (e.g., using SDT resources), receive an updated (e.g., second) SRSp configuration from the gNB, and / or send an SRSp using the updated (e.g., second) SRSp configuration.

[0263] The WTRU may select an SRSp configuration based on a detectable TRP. The WTRU may determine a set of one or more TRPs and SRSp configurations for satisfying positioning measurement accuracy requirements based on the number of TRPs detected using RSRP measurements of SSBs / RSs received from TRPs above an RSRP threshold. In an example, the WTRU may be configured to perform at least one of the following. The WTRU may receive configuration information including at least one of a first (e.g., default) SRSp configuration (e.g., low density) and a second SRSp configuration (e.g., high density), a TRP count threshold (e.g., the minimum number of TRPs detectable to satisfy accuracy requirements), or an RSRP threshold. The WTRU may perform RSRP measurements of SSBs / RSs received from detected TRPs. When the number of detected TRPs having an RSRP above the RSRP threshold is greater than the TRP count threshold, the WTRU may select a first SRSp configuration (e.g., low density) and / or send an SRSp using a first (e.g., default) SRSp configuration. When the number of detected TRPs with RSRPs above an RSRP threshold is less than a TRP count threshold, the WTRU may select a second (e.g., updated) SRSp configuration (e.g., high density), transmit an indication to the gNB (e.g., in an RRC message or MAC CE using SDT resources) to request activation of the second (e.g., updated) SRSp configuration, and / or when receiving the activation indication, send the SRSp using the second (e.g., updated) SRSp configuration.

[0264] The WTRU may select an SRSp configuration based on an expected measurement accuracy in a positioning area in which the WTRU is located. A WTRU in low power operation (e.g., INACTIVE state) may select an SRSp configuration based on an expected measurement accuracy in a positioning area in which the WTRU is located. In an example, the WTRU may be configured to perform at least one of the following. The WTRU may receive configuration information (e.g., in an RRCRelease message) that includes at least one of a first (e.g., default) SRSp configuration (e.g., low density), a second (e.g., new) SRSp configuration (e.g., high density), or an RSRP threshold. The WTRU may perform RSRP measurements of the SSB / RS received from the TRP. When the RSRP measurement is above the RSRP threshold, the WTRU may send an indication to the gNB (e.g., via an RRC message or MAC CE using SDT resources) to request activation of the first SRSp configuration (e.g., low density) and / or send an SRSp using resources in the first SRSp configuration (e.g., possibly upon receipt of an activation indication and an SRSp activation time window). When the RSRP measurement is below the RSRP threshold, the WTRU may send an indication to the gNB (e.g., via an RRC message or MAC CE using SDT resources) to request activation of a second (e.g., updated) SRSp configuration (e.g., high density) to send SRSp using resources in the second (e.g., updated) SRSp configuration (e.g., possibly upon receipt of an activation indication and an SRSp activation time window). The WTRU may send a deactivation indication to the gNB to terminate or release the first SRSp configuration (e.g., after expiration of the activation time window).

[0265] Examples of supporting positioning using Mobile Terminated Small Data Transmission (MT-SDT) are provided herein. A WTRU may be configured with MT-SDT to support positioning in low power operation (eg, power saving state or INACTIVE / IDLE state / mode / operation).

[0266] If in low power operation (e.g., RRC INACTIVE / IDLE state), the WTRU may be configured with configurations and / or resources associated with MT-SDT for supporting at least one of: DL-based; UL-based; DL and UL-based positioning or RAT-independent positioning examples (e.g., any RAT-independent positioning example (e.g., GNSS)). MT-SDT may refer to any procedure, configuration, and / or functionality that the WTRU and / or network may support for DL ​​reception using SDT resources (e.g., RA-SDT, CG-SDT). If transitioning (e.g., before and / or after transitioning) to the RRC INACTIVE / IDLE state, such DL reception may include at least one of the following if MT-SDT is supported: data / control messages; assistance data; configuration information; or any LPP / LCS messages. In an example, MT-SDT may include at least one of the following that the WTRU may receive in the INACTIVE / IDLE state: any of the measurement configurations; PRS; or other reference signals (e.g., TRS, CSI-RS). When operating in the INACTIVE / IDLE state (e.g., possibly after MT-SDT is triggered / activated), the WTRU may receive (e.g., in the case of positioning) at least one of: a DL data / control message (e.g., LPP / LCS message, activation / deactivation indication); or a PRS. The activation or deactivation command may be associated with a measurement gap or PRS processing window for processing measurements made on the PRS.

[0267] In an example, MT-SDT may be configured together with MO-SDT, where both MO-SDT and MT-SDT may be configured in the WTRU at the same time (e.g., via RRCRelease), or MT-SDT may be activated when MO-SDT is activated. In an example, MT-SDT may be configured and / or activated independently of MO-SDT. In an example, MT-SDT may be triggered and / or activated (e.g., explicitly triggered / activated) when the WTRU receives a configuration and / or indication associated with activation of MT-SDT (e.g., any of the configuration and / or indication). In an example, MT-SDT may be activated / triggered (e.g., implicitly activated / triggered) when the WTRU receives at least one of the following: a DL data / control message (e.g., a paging message); or a PRS in an INACTIVE state. The WTRU may receive (eg, in both cases) at least one of: a DL data / control message; or a PRS via MT-SDT if (eg, after) MT-SDT is activated / triggered (eg, explicitly or implicitly).

[0268] The WTRU may be (pre)configured with one or more MT-SDT configurations and / or triggers to use MT-SDT by the network (e.g., serving base station / cell or LMF) via one or more of: RRC messages; reciprocity with MO-SDT; paging messages; or WTRU-initiated indications / requests.

[0269] For RRC messages, when transitioning to low power operation (e.g., RRC INACTIVE state), the WTRU may receive a configuration associated with the MT-SDT in an RRC release message (e.g., with a suspended configuration). The WTRU may receive the MT-SDT configuration via an RRC reconfiguration message and / or an RRC resume message (e.g., possibly while in the INACTIVE state). When an RRC reconfiguration / RRC resume message for MT-SDT is received, the WTRU may receive an indication / flag indicating that the low power operation (e.g., INACTIVE state) is maintained. In an example, the WTRU may receive a paging message that may include the MT-SDT configuration in a received RRC reconfiguration / RRC resume message (e.g., together with the paging message). In an example, the WTRU may receive a paging message (e.g., subsequently received) an RRC reconfiguration / RRC resume message (e.g., which may include the MT-SDT configuration). If in the RRC CONNECTED state, the WTRU may receive the MT-SDT configuration via the RRC reconfiguration. When an activation indication is received (eg, after receiving) via an RRC release message and / or a paging message, the MT-SDT configuration in the WTRU may (eg, may then) be activated.

[0270] For reciprocity with MO-SDT, if the WTRU is configured with a MO-SDT configuration (e.g., via an RRC release message) and / or if the MO-SDT configuration is triggered (e.g., based on a first / initial transmission performed by the WTRU utilizing MO-SDT resources), the WTRU may use all or a subset of the configuration associated with MO-SDT for MT-SDT. In an example, when MO-SDT is triggered (e.g., when the WTRU performs a first / initial transmission utilizing MO-SDT resources), the WTRU may receive a configuration for MT-SDT or an activation / deactivation indication for MT-SDT (e.g., possibly via DL message / signaling (e.g., in RRC, MAC CE, or DCI)).

[0271] For paging messages, when one or more paging messages are received, the WTRU may receive an MT-SDT configuration or an indication to activate / deactivate a pre-configured MT-SDT configuration. In an example, the paging message received by the WTRU may include a WTRU ID (e.g., I-RNTI, paging I-RNTI) within a DCI and / or a flag / indication that may indicate the presence of an MT-SDT configuration. When such DCI is detected, the WTRU may demodulate and / or decode the corresponding PDSCH to extract the MT-SDT configuration in the paging message. In an example, when a paging message (which may indicate the presence of an MT-SDT configuration for the WTRU) is received (e.g., after receiving) in one or more paging occasions, the WTRU may initiate a RACH process by sending a RACH preamble. The WTRU may (e.g., may then) receive an MT-SDT configuration or an activation / deactivation indication for a pre-configured MT-SDT via a RA-SDT or an initial access message (e.g., Msg 2, Msg 4, or Msg B). In an example, when SDT resources (e.g., CG-SDT) are configured and when a paging message is received (e.g., after receiving), the WTRU may send a request message (e.g., RRC request or RRC recovery) for at least one of the following: to initiate SDT; to request MT-SDT configuration; or to activate (deactivate) a pre-configured MT-SDT. The WTRU may (e.g., may then) receive an MT-SDT configuration or an activation (deactivation) indication for a pre-configured MT-SDT in the DL (e.g., via RRC, MACCE, DCI). Such UL and DL messages may be sent / received by the WTRU using SDT resources while remaining in low power operation (e.g., INACTIVE state). The WTRU may receive an indication in a paging message (e.g., RRC or PDCCH signaling) that indicates to the WTRU to transition to a different RRC state or to perform an RRC recovery procedure (e.g., which may be associated). A WTRU configured with a DL SDT may monitor a subset of paging occasions (or a subset of P-RNTIs). Such partitioning may be configured and may be associated with reception of DL SDT or an initiated DL SDT process.

[0272] For WTRU initiated indication / request, when (e.g., any) indication or request message is transmitted in RRC CONNECTED or RRC INACTIVE state (e.g., in SDT), the WTRU (while in low power operation (e.g., INACTIVE state)) may receive MT-SDT configuration for receiving data / control messages in DL. Such indication and / or request message may include one or more of: assistance information for configuring DRX (e.g., cycle duration, on-duration, offset start time associated with PRS measurement); request for configuring / activating measurement gaps; or request / assistance information for configuring configured grants / SPS (e.g., payload size and / or periodicity for receiving periodic assistance data / LPP messages from LMF). The WTRU may receive configuration related to at least one of: MT-SDT (e.g., DL CG resources, applicable DL SDT RBs, other positioning (e.g., aforementioned positioning) related configurations, etc.); as part of an RRC release message; as part of a paging message; or via broadcast signaling. The WTRU may request such configuration or a subset thereof if performing cell reselection, gNB reselection, crossing a RAN notification area or tracking area.

[0273] If an indication is received to initiate a DL SDT procedure (e.g., which may be conditional on receiving a TA command or conditional on having UL timing synchronization (e.g., TA timer or CG-TAT running)), the WTRU may activate resources configured for UL SDT (e.g., CG-SDT resources). In an example, if a paging indication / trigger is received (e.g., after receiving) indicating the initiation of a DL SDT procedure, the WTRU may activate the CG-SDT resources. If a paging indication / trigger is received indicating the initiation of a DL SDT procedure, the WTRU may start CG-TAT.

[0274] Configuration information associated with MT-SDT may be received by the WTRU using at least one of: radio bearer configuration; radio resource configuration; validity condition; timing advance (TA) / TA timer configuration; RSRP difference threshold configuration; positioning related configuration; priority value; service related configuration; or DRX configuration.

[0275] For radio bearer configuration, the WTRU may be configured with one or more DRBs and / or SRBs (e.g., SRB0, SRB1, SRB2, SRB3) (e.g., which may be used after MT-SDT is triggered / activated). The WTRU may be configured with one or more parameters associated with the DRB / SRB for MT-SDT, including: parameters associated with sublayers / entities of the DRB / SRB, such as Service Data Adaptation Protocol (SDAP), PDCP (e.g., ROCH, encryption / encryption coding, integrity protection, packet duplication); RLC mode (e.g., AM, UM, TM); MAC entity (e.g., priority, logical channel priority (LCP), logical channel (LCH) limit, data volume threshold of TB) or physical layer (PHY).

[0276] For radio resource configuration, the WTRU may be configured with one or more RA-SDT and / or CG-SDT configurations. If MT-SDT is activated (e.g., after), the WTRU may use RA-SDT and / or CG-SDT configurations to receive DL data (e.g., in PDSCH). The RA-SDT configuration may include at least parameters corresponding to ID, payload size, data amount, message type (e.g., Msg 2, Msg 4, Msg B), etc. applicable when MT-SDT is triggered. The CG-SDT configuration may include at least parameters corresponding to ID, start offset slot, periodicity, payload size, etc. that can be used by the WTRU when MT-SDT is triggered. The WTRU may be configured with one or more resource configurations for receiving data / control messages and / or PRS when MT-SDT is triggered and / or activated (e.g., after), including at least one of BWP (e.g., initial, non-initial), carrier, beam, or time / frequency resource pool.

[0277] For validity conditions, the WTRU may be configured with one or more validity conditions associated with the validity of the MT-SDT configuration. Such validity conditions may include regional validity (e.g., a list of cells / cell IDs) and / or temporal validity (e.g., a duration / window), where the corresponding MT-SDT configuration may be assumed by the WTRU to be valid for use. In an example, the validity condition indicating the validity of the MT-SDT configuration may include a reception count. The WTRU may be configured (e.g., in this case) to have N receptions associated with the MT-SDT. For example, the MT-SDT configuration may be activated during the first reception and / or may be deactivated after the nth reception.

[0278] For timing advance (TA) / TA timer, the WTRU may be configured with a TA timer associated with the MT-SDT configuration, which may be used to determine whether the MT-SDT is valid for use. When the TA timer expires, the WTRU may stop / suspend use of the associated MT-SDT configuration and / or may release the MT-SDT configuration. Upon receiving a TA command, the WTRU may restart the TA timer associated with the MT-SDT.

[0279] For RSRP difference thresholds, the WTRU may be configured with one or more RSRP difference thresholds associated with the MT-SDT configuration, which may be used to determine whether MT-SDT is valid for use. In an example, if the RSRP difference measured between a DL signal (e.g., an RRC release message) that transitions the WTRU to the INACTIVE state and another DL signal (e.g., any DL signal that may be associated with MT-SDT) is greater than or less than a threshold, the WTRU may stop / suspend use of the associated MT-SDT configuration and / or may release the MT-SDT configuration.

[0280] For positioning-related configurations, the WTRU may be configured with one or more MT-SDT configurations associated with positioning. Such MT-SDT configurations may include resources (e.g., CG-SDT, RA, SDT) and / or radio bearers (e.g., SRBs) for receiving at least one of the following: one or more positioning-related messages (e.g., LPP / LCS messages; one or more activation (deactivation) indications; or one or more positioning configurations (e.g., SRSp and / or PRS configurations)).

[0281] For a priority value, the WTRU may receive a priority value associated with one or more MT-SDT configurations. The WTRU may decide whether to use an MT-SDT configuration to receive DL data or which MT-SDT configuration to use to receive DL data (e.g., during a DRX cycle when in an INACTIVE / IDLE state) (e.g., based on the associated priority value). The priority value may be associated with a PRS resource configured for the WTRU. In an example, the WTRU may receive a priority level associated with a PRS processing window, during which the WTRU may determine to process the PRS based on the priority level. If the priority of the PRS is lower than other DL signals or channels, the WTRU may determine to defer processing of measurements performed on the PRS. If the priority level of the PRS is higher than other DL signals or channels, the WTRU may determine to prioritize processing of measurements performed on the PRS.

[0282] For service-related configurations, the WTRU may be configured to receive data in the DL with different payload sizes via MT-SDT. The WTRU may (e.g., may also) be (pre-)configured with different MT-SDT configurations, which may be associated with different payload sizes. The WTRU may select / use (e.g., in this case) a suitable MT-SDT configuration for receiving DL data within a certain payload size based on an indication received from the network (e.g., a paging message that may indicate an ID of the MT-SDT configuration to be used or information about the payload size of the DL data). In an example, the WTRU may be configured to receive periodic or semi-persistent data in the DL via MT-SDT. The WTRU may be (pre-)configured with different MT-SDT configurations, which may be associated with different periodicity values. The WTRU may (e.g., may also) be configured with different parameters associated with receiving periodic / semi-persistent data via MT-SDT (e.g., including start / stop offset times and duration / windows). The WTRU may select / use (eg, in this case) an appropriate MT-SDT configuration for receiving DL data within a certain periodicity (eg, possibly based on an indication received from the network (eg, a paging message)).

[0283] For DRX configuration, if in low power operation (e.g., INACTIVE / IDLE mode / state), the WTRU may be configured with one or more DRX configurations. Such DRX configurations may be aligned with MT-SDT resources / configurations (e.g., the periodicity of the ON / active time of DRX may be aligned with the periodicity of the CG-SDT of MT-SDT). The WTRU may (e.g., may also) be configured with different DRX parameters, including DRX cycle duration, ON duration, and inactivity timer, which may be aligned with MT-SDT resources for receiving DL data if in INACTIVE / IDLE mode / state.

[0284] In an example, when MT-SDT is initiated / activated for DL ​​reception (e.g., first DL reception), MT-SDT may remain active for another DL reception (e.g., further DL reception), for example until an explicit indication (e.g., RRC reconfiguration message) or an implicit indication (e.g., WTRU moves to a new cell, TA timer expires) indicating deactivation of the MT-SDT configuration is received from the network. When an indication associated with MT-SDT is received from the network (e.g., TA command), the MT-SDT configuration may be reactivated / restarted. In an example, the configured and / or activated MT-SDT configuration may remain activated for further DL reception, at least until an indication (e.g., RRC release) of releasing the MT-SDT configuration and / or an indication of transitioning from the RRC INACTIVE state to the RRC CONNECTED state (e.g., RRC resume request) is received from the network.

[0285] If a DL SDT TB is received (e.g., after receiving a DL SDT TB), the WTRU may monitor the reception of another (e.g., subsequent) DL SDT TB. The subsequent DL SDT TB may be received as a DL transmission (e.g., a subsequent DL transmission) on a configured DL CG-SDT resource, RA-SDT resource, or as a scheduled PDSCH DL assignment. The WTRU may monitor the PDCCH resources, search space, or CORSET for the reception or assignment of another (e.g., subsequent) DL SDT TB.

[0286] In an example, the WTRU may (e.g., conditionally) monitor another (e.g., subsequent) DL SDT if at least one of the following is met: the TB configured for the DL SDT is multiplexed with the TB of the initial DL SDT; the RRC message does not exist, is multiplexed or not multiplexed with the initial DL SDT TB (e.g., an RRC release message); or the TB size of the initial DL SDT TB is less than or greater than a configured threshold.

[0287] An example of a WTRU receiving an indication / information regarding positioning via MT-SDT in low power operation (e.g., RRC INACTIVE / IDLE mode) is provided herein. When operating in RRC INACTIVE / IDLE mode, the WTRU may receive one or more indications / messages associated with positioning (e.g., LCS / LPP messages) from the network (e.g., RAN and / or LMF). Such positioning messages may include at least one of those messages related to: MT-LR; delayed MT-LR; or MO-LR positioning services. The positioning message / indication may be received by the WTRU via MT-SDT (e.g., in the case where MT-SDT is initiated / running due to a previous DL SDT reception or UL SDT transmission). In an example, receiving a positioning message / indication may trigger / activate a pre-configured MT-SDT configuration in the WTRU (e.g., in the case where MT-SDT is not initiated).

[0288] If MT-SDT is configured and / or if the pre-configured MT-SDT configuration is activated, the WTRU may receive one or more of the following positioning-related messages / indications / configurations in INACTIVE / IDLE mode: LCS message, LPP message, or RAN-related configuration.

[0289] LCS messages may include messages (e.g., any messages) related to MT-LR, delayed MT-LR, and MO-LR (e.g., positioning service request, ACK / NACK status confirmation, positioning report), which the WTRU may receive from the network (e.g., base station, LMF, AMF, etc.).

[0290] The LPP message may include one or more of the following: an LPP request for capability information; an LPP provision of assistance data; or an LPP request for location information. For an LPP request for capability information, the WTRU may receive a request to support at least one of the following positioning examples: DL-based; UL-based; or DL- and UL-based. For LPP provision of assistance data, the WTRU may receive one or more PRS and / or SRSp configurations (e.g., as described herein) to support at least one positioning example. Such configurations may be received in an LPP assistance data message and / or an RRC message. The WTRU may (e.g., may also) receive assistance data (e.g., location information of the TRP / gNB, beam direction, line-of-sight angle, correction information) based on whether the network requests WTRU-based positioning or WTRU-assisted positioning. For an LPP request for location information, the WTRU may receive an LPP message from the LMF, possibly together with at least one of the following: a response time indicating a duration for performing measurements, processing measurements, or reporting results to the network.

[0291] The RAN-related configuration may include at least one of the following: SRSp resources / configuration; activation / deactivation indication for SRSp / PRS configuration; measurement gap (MG) configuration; or correction information. For SRSp resources / configuration, the WTRU may receive at least one of the following: SRSp configuration (e.g., aperiodic SRSp, semi-persistent SRSp, or periodic SRSp); or parameters associated with the SRSp configuration (e.g., ID, start offset slot, periodicity). The configuration information may be received in an RRC message (e.g., RRC release), MAC CE, and / or DCI. For the SRSp configuration, the WTRU may be configured with activation / deactivation rules for determining when to start and stop SRSp transmission when (e.g., after) receiving the SRSp configuration. In an example, the WTRU may start transmission of SRSp (e.g., using the resources of the configured semi-persistent or periodic SRSp) after (e.g., immediately after) receiving the associated SRSp configuration (e.g., without any explicit activation indication). When (eg, any one of) the validity conditions associated with MT-SDT or MO-SDT (eg, TA, RSRP difference threshold) expire, the WTRU may stop SRSp transmission (eg, for periodic or semi-persistent SRSp).

[0292] For activation / deactivation indication for SRSp / PRS configuration, the WTRU may start / stop sending SRSp (e.g., semi-persistent SRSp or aperiodic SRSp) based on explicit or implicit indication received from the network. Such activation (deactivation) indication may be received by the WTRU via MT-SDT, MAC CE, or DCI in an RRC message.

[0293] For measurement gap (MG) configuration, the WTRU may receive at least one of: a configuration associated with the MG; or an indication of activation / deactivation of a pre-configured MG via MT-SDT. Such MG-related configuration and / or indication may be received by the WTRU when a request for MG indication is sent (e.g., after sending) during a CONNECTED state or an INACTIVE state (e.g., via UL SDT). If in an INACTIVE / IDLE state, such MG-related configuration and / or indication received via MT-SDT may be used to perform DL-PRS measurements.

[0294] For correction information, the WTRU may receive correction information such as a timing error group (TEG) via MT-SDT. Such correction information may be received by the WTRU when sending (e.g., after sending) a request indication during the CONNECTED state or the INACTIVE state (e.g., via UL SDT). When operating in a WTRU-based positioning mode, the WTRU may use such correction information to determine the WTRU position.

[0295] The WTRU may receive an LPP request for WTRU capability information and / or LPP assistance data, which may be piggybacked when an LCS request is received via MT-SDT. The WTRU may receive (e.g., in this case) one or more LPP messages (e.g., LPP messages described herein) in a single MT-SDT reception (e.g., a single NAS / LPP message) or in multiple MT-SDT receptions (e.g., multiple NAS / LPP messages).

[0296] If MT-SDT is configured in the WTRU and / or was not previously initiated, then receiving a message / indication (e.g., any of the messages / indications described herein) may result in initiation / activation of MT-SDT for the WTRU in the INACTIVE state. In an example, if MT-SDT is initiated / activated (e.g., after MT-SDT is initiated / activated), the WTRU may transmit a request message to change / update the activated MT-SDT configuration or a request to release the MT-SDT configuration to the base station (e.g., possibly upon transitioning from the INACTIVE state to the CONNECTED state). Such a request to change and / or release MT-SDT may be transmitted by the WTRU to the base station due to at least one of the following triggers: service / QoS requirements; DRX misalignment; or positioning requirements.

[0297] For service / QoS requirements, if data is received in the DL during the INACTIVE / IDLE state, the WTRU may transmit a request indication for changing the MT-SDT to meet a certain QoS requirement (e.g., latency, data rate). If a QoS change (e.g., latency increases above / below a threshold, bit rate decreases above / below a threshold) is detected for data received in the DL during the INACTIVE / IDLE state, the WTRU may (e.g., may also) transmit a request indication.

[0298] For DRX misalignment, if a misalignment (eg, any misalignment) between data reception in the DL and the DRX configured in the WTRU during INACTIVE / IDLE state is detected, the WTRU may transmit a request indication for changing the MT-SDT.

[0299] For positioning requirements, the WTRU may transmit a request indication for changing the MT-SDT if a change associated with positioning is detected including at least one of the following: a change in the achievable positioning accuracy; a change in the PRS / SRSp configuration used; or a change in the MG configured in the WTRU for performing positioning measurements.

[0300] In an example, the WTRU may receive an activation / deactivation command for the transmission of SP-SRSp or related positioning measurement and reporting procedures during a DL SDT procedure (e.g., part of a PDSCH payload or part of an MT-SDT configuration). If a paging message is received that may or may not be associated with a DL SDT (e.g., part of the paging message itself or part of a PDCCH indicated as scheduling a paging message), the WTRU may activate / deactivate the transmission of SP-SRSp or related positioning measurement and reporting procedures. In an example, if a PDCCH including the WTRU's P-RNTI or the WTRU's ID is received (e.g., as may be the case when a paging message is associated with a DL SDT), the WTRU may activate / deactivate the transmission of SP-SRSp or related positioning measurement and reporting procedures.

[0301] In an example, when a configured timer expires, the WTRU may deactivate or activate SP-SRSp or related positioning measurement and reporting procedures. The WTRU may reset such timers if (e.g., each time) the WTRU receives a response or DL ​​transmission (e.g., any DL transmission such as PRS, DL SDT TB, or PDCCH) from the network.

[0302] Examples of WTRU behaviors / actions associated with positioning based on whether MT-SDT is configured and / or initiated are provided herein. In an example, the WTRU may determine positioning examples that may be supported (e.g., DL-based, UL-based, DL and UL-based, or MT-LR / delayed MT-LR) and / or indicated to the network (e.g., indicated to the LMF) (e.g., possibly in WTRU capability information) based on whether MT-SDT and / or MO-SDT are configured and / or activated in the WTRU. In an example, if both MO-SDT and MT-SDT are configured and / or activated in the WTRU, the WTRU may indicate that the WTRU supports MT-LR and / or defers MT-LR positioning during low power operation (e.g., INACTIVE state). In an example, if MO-SDT is configured and / or activated (e.g., only MO-SDT), the WTRU may indicate that the WTRU supports delayed (e.g., only delayed) MT-LR.

[0303] In an example, the WTRU may decide whether to transmit / which LPP messages to the network and / or which corresponding LPP messages may be received based on whether MT-SDT is configured and / or activated. In an example, when MT-SDT is configured and / or activated, the WTRU may decide to transmit a request for assistance data to the network because the WTRU may receive corresponding LPP assistance data via MT-SDT.

[0304] In an example, when operating in the INACTIVE state, the WTRU may decide whether to perform PDCCH monitoring (e.g., possibly during the ON duration of DRX) to receive paging messages or DL ​​data (e.g., positioning information) based on whether MT-SDT is configured and / or activated. In an example, if the WTRU transmits an LCS / LPP request message (e.g., a request for assistance data) to the network, the WTRU may assume that the corresponding DL data (e.g., LPP assistance data) is received by the WTRU. The WTRU may skip monitoring the PDCCH for receiving DL data (e.g., any DL data) in the PDSCH (e.g., if MT-SDT is not configured / activated).

[0305] In an example, the WTRU may determine whether to receive / skip DL messages associated with positioning (e.g., periodic LPP messages) based on resources associated with a configured MT-SDT (e.g., RA-SDT, CG-SDT) in the WTRU. The WTRU may skip receiving certain DL data (e.g., if it is determined that the payload size or periodicity of the DL data expected to be received is not aligned with the resources associated with the configured and / or activated MT-SDT).

[0306] An example of a WTRU determining and transmitting to a network an indication of properties of expected DL positioning information based on a configured MT-SDT is provided herein. The WTRU may determine and / or provide assistance information / indications to the network to ensure that DL data (e.g., that may be associated with positioning (e.g., LPP / LCS messages)) may be received with resources and / or configurations associated with the MT-SDT.

[0307] In an example, if the payload size of an LCS / LPP message (e.g., aperiodic or periodic LPP assistance data) expected to be received by the WTRU is relatively small, the WTRU may receive the LPP message and perform PRS measurements while maintaining low power operation (e.g., INACTIVE state). When a DL LPP / LCS message is received during the INACTIVE state, the resources (e.g., CG-SDT, RA-SDT), periodicity, and / or data volume thresholds (e.g., payload limits) associated with the MT-SDT configuration may be insufficient and / or not properly aligned with the time opportunity. The WTRU may be transitioned (e.g., in this case) to the CONNECTED state to receive the LPP / LCS message (e.g., which may incur additional latency or signaling overhead).

[0308] In an example, in order to receive data with specific service characteristics via MT-SDT, the WTRU may provide assistance information to the network (e.g., base station and / or LMF). The assistance information may be provided so that the MT-SDT may be configured and / or triggered with knowledge of the data expected to be received by the WTRU (when in the INACTIVE state). The WTRU may provide the assistance information to the network. The assistance information may include at least one of: service information or segment related information.

[0309] For service information, the WTRU may provide information about the expected payload size of the data (e.g., average, minimum, maximum), periodicity (e.g., for periodic DL data), QoS requirements (e.g., latency, data rate, reliability), etc.

[0310] For segmentation related information, the WTRU may provide information / indication / flag regarding whether higher layer (e.g., LPP) segmentation is supported in the DL and / or UL. Based on such information, when a segmented packet data unit (PDU) is received, the WTRU may receive one or more pre-configured MT-LR configurations and / or an indication regarding which MT-LR configuration to activate / use. The WTRU may (e.g., may also) provide information regarding at least one of: an ID associated with a segmented PDU; the number of segments expected in the DL per LPP / LCS message / PDU; the expected / average payload size per segmented PDU; or a latency associated with delivering one or more segmented PDUs.

[0311] The WTRU may provide assistance information (e.g., any assistance information may be provided) to the network periodically (e.g., with a preconfigured periodicity) and / or when triggered by some events (e.g., upon detection of traffic changes, measurement changes, and / or mobility that may result in changes to any existing MT-SDT configuration).

[0312] In an example, the WTRU may determine attributes of positioning information to be received via MT-SDT, including a payload size and / or periodicity of the expected positioning information (e.g., periodic assistance data). The attributes of the positioning information may be determined based on a configuration (e.g., a periodic resource or data volume threshold associated with CG-SDT) that may be associated with MT-SDT (e.g., a signaling radio bearer (SRB) of MT-SDT).

[0313] In an example, the WTRU may determine whether positioning information (e.g., carried in a non-access stratum (NAS_message)) is to be segmented into one or more segments. Such determination may be based on a data amount threshold configuration associated with an SRB configured in the WTRU for receiving positioning information in the DL. The LMF may segment the positioning information (e.g., in this case) into different segments that may be less than or equal to the configured data amount threshold so that the segmented data may be delivered via the MT-SDT. In an example, if periodic positioning information (e.g., periodic LPP assistance data, or periodic ACK / NACK status indication in the case where the WTRU sends periodic reports) is delivered based on a periodicity configured for resources associated with the MT-SDT (e.g., CG-SDT), the WTRU may determine the periodicity to be used by the network (e.g., LMF). In an example, if segmented positioning information is delivered based on configured resources associated with the MT-SDT (e.g., CG-SDT), the WTRU may determine the number of segments to be applied and / or the payload size of the segments (e.g., each segment). In an example, if segmented data is transmitted in the DL based on the latency requirements associated with the positioning service configured in the WTRU and / or the expected latency for receiving DL data using the MT-SDT resources configured in the WTRU, the WTRU may determine the number of segments to be applied by the LMF.

[0314] When transmitting positioning information in the DL, the WTRU may transmit an indication / request to the network (e.g., to the LMF via an LPP message) regarding the determined attributes of the positioning information to be used (e.g., periodicity, payload size, whether to be segmented, number of segments to be used). In an example, when the attributes of the positioning information expected in the DL are determined, the WTRU may transmit an indication to the network (e.g., to the base station via RRC, MAC CE, UCI, possibly when in CONNECTED / INACTIVE state). The indication may request an MT-SDT (e.g., a new MT-SDT) or change / update an existing MT-SDT configuration so that the MT-SDT configuration may be aligned with the expected reception of positioning information in the DL. In an example, if an indication of determined attributes of expected positioning information in the DL is transmitted to the network (e.g., transmitted to the base station via RRC, MAC CE, UCI, possibly while in a CONNECTED / INACTIVE state), the WTRU may receive a DRX configuration for use during the INACTIVE / IDLE state (e.g., a new / updated DRX configuration) that may be aligned with the expected reception of positioning information in the MT-SDT and / or DL.

[0315] An example of a WTRU receiving positioning information in the DL based on a data volume threshold configured for MT-SDT is provided herein. A WTRU in low power operation (e.g., INACTIVE state) may receive one or more types of positioning information (e.g., PSR / SRSp configurations and / or LPP messages) using MT-SDT configuration for one or more SRBs based on a data volume threshold associated with the SRB. Different SRBs (e.g., SRB0, SRB1, SRB2, SRB3) may be configured in the WTRU (e.g., in this case) for carrying and / or delivering positioning information using MT-SDT. Different SRBs configured for MT-SDT in the WTRU may be configured with one or more data volume thresholds associated with different types of positioning information.

[0316] When triggered by the arrival of a higher layer indication (e.g., indicating expected reception of positioning information), a data volume threshold may be used to resume an SRB (e.g., SRB2) configured for MT-SDT. In an example, when the size of the expected positioning information (e.g., in a NAS message) is less than or equal to the data volume threshold configured for SRB2, the WTRU may transmit an indication to the network to request resumption and / or activation of SRB2 for receiving RRC messages and / or NAS messages in MT-SDT. The data volume threshold may be configured by the LMF or the gNB. The method (e.g., similar method) for receiving positioning information using SDT when the WTRU is in the INACTIVE state may (e.g., may also) be applicable when the WTRU is in the IDLE state.

[0317] In an example, based on the size of the positioning information determined by the WTRU, the WTRU may be configured with one or more SRBs (which may be used to carry / deliver the positioning information via MT-SDT). Based on an indication / information transmitted by the WTRU to the network (e.g., assistance information), the WTRU may be configured with a data amount threshold corresponding to the SRB (e.g., in this case). The indication / information may indicate the size of the positioning information to be carried or expected to be received using MT-SDT. In an example, if an indication is transmitted to the network (e.g., capability information, LCS / LPP message), the WTRU may indicate to the serving gNB the size of the positioning information (e.g., LPP assistance data) expected to be received in the DL when operating in the INACTIVE state. For example, the WTRU may transmit an indication of the size of the positioning information to the gNB in ​​an RRC message, a MAC CE, or a UCI. The WTRU may transmit an indication to the gNB if in the CONNECTED state, or during the INACTIVE state or after transitioning to the INACTIVE state (e.g., via UL SDT). If a corresponding data amount threshold is configured, the WTRU may (eg, may then) receive positioning information in an associated SRB (eg, SRB2) using MT-SDT.

[0318] In an example, the SRBs (e.g., SRB1, SRB2) configured for MT-SDT in the WTRU may be associated with different data volume thresholds for each SRB, where at least one data volume threshold may be activated for the SRB at a given time (e.g., any given time). The different data volume thresholds may be associated with a flag or indicator that may be used during triggering and / or activating MT-SDT (e.g., via paging). In an example, if the SRBs are initially configured for MT-SDT, a default data volume threshold may be activated and applicable. In an example, the WTRU may be configured with a default / first data volume threshold that may be aligned with the size of an expected NAS message carrying positioning information (e.g., an LPP message).

[0319] In an example, the data volume threshold may be dynamically changed and / or updated based on the triggering of the MT-SDT. The WTRU may determine (e.g., initially determine) whether the expected positioning information is less than a default / first data volume threshold (e.g., possibly based on the type of positioning message (e.g., LPP / LCS message) or message generated and sent by the WTRU in the UL). If the expected positioning information is determined to be above the first data volume threshold and / or less than or equal to the second configured data volume threshold, the WTRU may trigger activation of the MT-SDT. The activation of the MT-SDT may be triggered by transmitting a resume request (e.g., in a UL-SDT using RA-SDT or CG-SDT resources) to the network including an indicator / flag associated with the second data volume threshold. The WTRU may (e.g., may then) receive a positioning indication in the event of receiving a resume message (e.g., RRC resume in MT-SDT) indicating activation of the second data volume threshold. If the second data volume threshold remains activated and / or is not deactivated by the network, the WTRU may (e.g., in this case) continue to receive one or more positioning information messages (e.g., periodic assistance data). The data volume threshold (e.g., the aforementioned data volume threshold) may be configured by the LMF or the gNB.

[0320] An example is provided herein of a WTRU transmitting an indication / information regarding an RRC state and / or MO-SDT / MT-SDT configuration to an LMF in order to support an associated positioning procedure. The WTRU may transmit information indicating the WTRU RAN configuration. The information indicating the WTRU RAN configuration may include at least one of: its RRC state; MO-SDT and / or MT-SDT configuration; or a positioning configuration to be applied in the RRC state. The information indicating the WTRU RAN configuration may be transmitted to the LMF to support a location procedure associated with the RRC state / configuration. In an example, when transitioning from CONNECTED to low power operation (e.g., INACTIVE state), the WTRU may transmit an indication to the LMF so that the WTRU may receive assistance data (e.g., PRS configuration). When the WTRU is operating in the INACTIVE state, the assistance data may be applied. The WTRU may transmit an indication (e.g., the aforementioned indication) to the LMF via LPP, RRC, MAC CE, or UCI.

[0321] In an example, a WTRU may receive positioning information including one or more PRS configurations (e.g., optimized for low power operation) or updates to QoS requirements associated with positioning, including positioning accuracy and / or latency. The WTRU may receive positioning information based on information transmitted by the WTRU to the network in its RRC state, MT-SDT, and MO-SDT configurations. The positioning information received by the WTRU (e.g., in this case) may enable the WTRU to flexibly trade off between achieving high positioning accuracy, high device efficiency (i.e., low power consumption), and / or low latency positioning.

[0322] In an example, a WTRU may receive assistance data. The assistance data may include one or more PRS configurations for making measurements when operating in an INACTIVE / IDLE state. The PRS configuration may be based on an indication transmitted by the WTRU to the network regarding a current and / or future RRC state, MT-SDT, and MO-SDT configuration. The WTRU may receive a PRS configuration to be used when the WTRU operates in a particular RRC state and / or MO-SDT / MT-SDT configuration. When a first combination of MO-SDT and MT-SDT configurations is configured (e.g., with a high data volume threshold / payload size in UL / DL), the WTRU may use a first PRS configuration. When a second combination of MO-SDT and MT-SDT configurations is configured (e.g., with a low data volume threshold / payload size in UL / DL), the WTRU may (e.g., may also) use a second PRS configuration. Use of the first PRS configuration may result in shorter measurement duration and lower latency. Use of the second PRS configuration may result in low power operation and longer measurement duration / latency.

[0323] In an example, if the WTRU is configured with an SDT for transmitting data (e.g., positioning information) while in an INACTIVE state, the WTRU may receive a measurement reporting configuration from the network (e.g., LMF) indicating one or more parameters to be used when transmitting measurement reports while in an INACTIVE state. Parameters associated with the measurement reporting configuration (e.g., which may be received by the WTRU) may include at least one of: the type of measurements to be reported (e.g., enriched / reduced reporting); the amount of measurements to be reported (e.g., the size of each measurement report); or the periodicity of the reporting. Whether the reporting is reduced or enriched may be determined by the number of paths (e.g., additional paths) over which the WTRU reports the measurements.

[0324] The WTRU may report (e.g., in a simplified report) PRS measurements associated with a path (e.g., a primary path). In an enriched report, the WTRU may report PRS measurements associated with the primary path and N additional paths, where N may be configurable by the LMF. Parameters configured for measurement reporting may be received from the LMF (e.g., in one or more SRBs / DRBs) based on information transmitted by the WTRU regarding a data volume threshold configured for SDT. Based on knowledge of the (lower) data volume threshold configured for SDT at the LMF, the WTRU may be configured to transmit measurement reports (e.g., simplified measurement reports) in the INACTIVE state, e.g., with reduced granularity.

[0325] The WTRU may transmit MT-SDT configuration information for INACTIVE / IDLE mode operation to the LMF, including information about SRB / DRB (e.g., SRB2) and / or DRX configuration configured for MT-SDT. The WTRU may transmit information (e.g., the aforementioned information) to the LMF via LPP, RRC, MAC CE, or UCI. Configuration information for INACTIVE mode operation may be transmitted by the WTRU to the LMF if at least one of the following is received: LPP / LCS message; receiving a new / updated MT-SDT / MO-SDT configuration; receiving a new / updated DRX configuration; or when the WTRU RRC state is changed.

[0326] An example of a WTRU receiving an indication for use of an MT-SDT configuration during mobility is provided herein. When moving to a cell / gNB (e.g., a new cell / gNB), the WTRU may receive an MT-SDT configuration (e.g., a new or updated MT-SDT configuration) such that the WTRU may continue to receive (e.g., any one) DL messages / configurations and perform PRS measurements and / or SRSp transmissions while remaining in the RRC INACTIVE / IDLE state. The WTRU may be configured (e.g., initially configured) with MT-SDT (e.g., in an RRCRelease message) for receiving positioning information and / or SRSp configuration (e.g., periodically) from a source cell / TRP. The WTRU may (e.g., may also) be configured by the source cell / TRP (e.g., together with the MT-SDT configuration) with one or more validity conditions, including a TA timer, a validity duration, and / or a validity area (e.g., a cell ID list). If in the RRC INACTIVE / IDLE state, the WTRU may use one or more validity conditions to determine whether the MT-SDT configuration is valid for use.

[0327] If the WTRU moves to a cell (e.g., a new cell) where the cell ID (e.g., the new cell ID) may be within the valid area, the WTRU may use (e.g., may continue to use) the MT-SDT configuration to receive positioning information and / or configuration via the MT-SDT while in the RRC INACTIVE / IDLE state. In an example, a WTRU that may be configured with a semi-persistent SRSp may receive an activation indication (e.g., a MAC CE) from a source / first cell to activate SRSp transmission. A WTRU that may be configured with a semi-persistent SRSp may (e.g., may also) receive a deactivation indication (e.g., a MAC CE) to stop SRSp transmission from another / second cell. The activation and / or deactivation indications may be received via the MT-SDT (e.g., in this case, it may be because the MT-SDT is configured to be valid across different cells).

[0328] When one or more validity conditions expire, wherein the WTRU may move to a new / target cell / TRP that may be outside the validity area, the WTRU may transmit an indication to the network (e.g., in an RRC resume request via an initial access message or SDT). The WTRU may (e.g., may also) transmit a cause value indicating expiration / release of a previous MT-SDT configuration and / or a request for a MT-SDT configuration (e.g., a new MT-SDT configuration) in an indication of an ID. When acquiring the WTRU context from the source cell / TRP, the target cell / TRP may determine whether a new MT-SDT configuration may be allocated / activated for the WTRU or the WTRU may continue to use the previous MT-SDT configuration (e.g., possibly based on an identifier and / or request transmitted by the WTRU).

[0329] In response to an indication transmitted by the WTRU due to expiration of a previous MT-SDT configuration, the WTRU may receive one or more of the following from the target cell / TRP: an RRCResume message (e.g., in Msg B or Msg 4) indicating the use of a new MT-SDT configuration; an RRCRelease message (e.g., in Msg B or Msg 4) indicating the release of the previous MT-SDT configuration and / or the use of a new MT-SDT configuration; or an RRCRelease message indicating the continued use of the previous MT-SDT configuration.

[0330] The RRCResume message and / or the RRCRelease message may include parameters associated with the new MT-SDT configuration (e.g., RA-SDT and / or CG-SDT resources) or may include an activation indication (e.g., the ID of the configuration) to activate a pre-configured MT-SDT configuration.

[0331] An example of a WTRU receiving assistance data / configuration for positioning via MT-SDT during mobility is provided herein. If the WTRU continues to operate in the RRC INACTIVE / IDLE state while moving to a cell / TRP (e.g., a new cell / TRP), the WTRU may receive assistance data / configuration via MT-SDT, which may include one or more positioning configurations (e.g., PRS / SRSp configurations). If the LCS / LPP process for positioning is triggered within the coverage of the source cell / TRP, the WTRU may (e.g., initially) receive assistance data via broadcast, dedicated RRC signaling, or LPP messages. If a transition is made to low power operation (e.g., RRC INACTIVE / IDLE state) (e.g., in an RRC RELEASE message) or if in low power operation (e.g., INACTIVE / IDLE state) (e.g., via MT-SDT), the WTRU may receive assistance data in dedicated signaling when in the CONNECTED state (e.g., in this case).

[0332] The WTRU may receive a validity condition associated with the assistance data (e.g., via a validity timer / timer duration or a list of cell IDs in a validity zone), which may be used to determine whether the assistance data (e.g., PRS / SRSp configuration) is valid for use when in the RRC INACTIVE / IDLE state. In an example, the WTRU validity condition for the assistance data may be associated with the validity condition of the MT-SDT configuration. If the MT-SDT configuration is determined to be valid / invalid (e.g., in this case), the WTRU may assume that the assistance data may (e.g., may also) be valid / invalid. If the WTRU determines that the assistance data is valid / invalid, the WTRU may assume that the MT-SDT configuration is valid / invalid.

[0333] The WTRU may receive a configuration / rule for determining whether to transmit a request for assistance data (e.g., new assistance data) in dedicated NAS / RRC signaling, UL SDT, or to obtain assistance data (e.g., new assistance data) via broadcast RRC signaling (e.g., SIB) (e.g., possibly including an on-demand SIB). In an example, the configuration / rule may indicate a first set of one or more cell / TRPIDs, where the WTRU may be allowed to transmit a request for (e.g., new) assistance data (e.g., PRS / SRSp configuration). The configuration / rule may (e.g., may also) indicate a second set of one or more cell / TRP IDs, which may at least partially overlap with the first set, from which the WTRU may receive assistance data (e.g., new assistance data) in MT-SDT.

[0334] A WTRU in RRC INACTIVE state may transmit a request message (e.g., RRCResumeRequest message via SDT) for assistance data (e.g., new assistance data) for one or more (e.g., new) PRS and / or SRSp configurations if the conditions / rules associated with the transmission request are met (e.g., the new cell / TRP ID is outside the validity area). The WTRU may include an identifier (e.g., I-RNTI) associated with the WTRU and / or previous assistance data (e.g., PRS / SRSp configuration ID) in the indication. The cell / TRP (e.g., new cell / TRP) may acquire the WTRU context from the source cell / TRP based on the WTRU ID received from the WTRU and the request for assistance data (e.g., new assistance data). The WTRU may include a cause value indicating expiration and / or release of the previous assistance data / configuration in the indication for requesting new assistance data. In response to the request, the WTRU may receive at least one of: new assistance data (e.g., via MT-SDT); an activation indication for preconfigured assistance data (e.g., for preconfigured PRS / SRSp configuration); or an indication to continue using previous assistance data. The WTRU may receive a response indication in a RRCResume message, a RRCRelease message (e.g., in Msg B or Msg 4), or in a MT-SDT.

[0335] Examples associated with supporting DL and UL based LPHAP are provided herein. If in low power operation (e.g., INACTIVE / IDLE state), the WTRU may be configured to perform DL and UL based LPHAP (e.g., using multi-RTT positioning techniques) based on measurements of DL-PRS and / or transmission of UL-SRSp in one or more RTT cycles. DL and UL based positioning may include a first phase and a second phase. The first phase and the second phase may include DL-PRS reception and / or measurement at the WTRU and UL-SRSp transmission from the WTRU to the TRP. In WTRU-assisted DL and UL based positioning, the WTRU may report DL-PRS measurements (e.g., RSRP, PRS arrival time (ToA), RSTD measurements) and / or PRS reception and SRSp transmission timing difference measurements (e.g., WTRU Rx-Tx) to the network. In the case of multi-RTT positioning, the position of the WTRU may be determined based on one or more of: PRS measurements performed by the WTRU; SRSp measurements performed by the TRP / gNB; WTRU Rx-Tx measurements; or TRP / gNB Tx-Rx measurements. In DL- and UL-based LPHAP, the WTRU may apply and / or combine (e.g., any) techniques associated with DL- and UL-based LPHAP (e.g., as described herein). Such techniques may include one or more of the following: mitigating positioning errors in DL- and UL-based positioning; applying condition-dependent configuration / resources; aligning DL-PRS transmission and UL-SRSp reception; applying intra-band resources to DL-PRS and UL-SRSp transmissions; or applying inter-band resources to DL-PRS and UL-SRSp transmissions.

[0336] To mitigate positioning errors in DL and UL based positioning, if a positioning error (e.g., any positioning error) is detected when performing UL based positioning in the second phase (e.g., UL-SRSp transmission), the WTRU may switch from the estimation / prediction mode to the measurement mode (e.g., DL-PRS measurement) for DL ​​based positioning in the first phase. In an example, if a positioning error is detected when performing DL based positioning in the second phase, the WTRU may switch between the estimation / prediction mode and the measurement mode for UL based positioning in the first phase. The WTRU may be configured with one or more thresholds by the network. The one or more thresholds may be associated with the positioning error used to determine whether / when to switch between the measurement mode and the estimation mode. The WTRU may use information about the positioning error detected in the first phase to apply certain corrections in the second phase. In an example, when performing RSRP measurements of the DL-PRS received in the first phase and / or RSRP measurements below a threshold, the WTRU may perform SRSp transmission in the second phase using the selected SRSp configuration (e.g., high Tx power, high repetition, high periodicity), which may result in improved measurement accuracy. Such a scenario may occur when the WTRU is located in a coverage limited area or an area with poor radio link quality. When the RSRP measurement of the PRS is above a threshold, the WTRU may send the SRSp using an SRSp configuration (e.g., low Tx power, low repetition, low periodicity), which may result in improved power savings at the WTRU.

[0337] In order to apply condition-dependent configuration / resources, the WTRU may be pre-configured with PRS / SRSp resources / configuration. The PRS / SRSp resources / configuration may depend on one or more cells / zones / areas in which the WTRU will be located or expected to move to. If located in a cell / area associated with PRS / SRSp resources, the WTRU may (for example, in this case) use certain PRS / SRSp resources for UL and DL positioning. The WTRU may be pre-configured with conditions and / or restrictions for using PRS / SRSp resources. In an example, the WTRU may be configured with conditions associated with radio link quality, including one or more of RSRP, path loss thresholds (for example, RSRP of PRS, SSB), or TA, to determine whether the WTRU can use the SRSp configuration (for example, after performing PRS measurements). When (for example, only when) the RSRP measured by the PRS is lower than the threshold, the WTRU may (for example, in this case) use a restricted set of SRSp resources.

[0338] In order to align DL-PRS transmission and UL-SRSp reception, the WTRU may be configured to use one or more time windows and / or DRX cycles. One or more time windows and / or DRX cycles may be applied during the INACTIVE / IDLE state (e.g., such that DL PRS reception and / or UL SRSp transmission may be performed within a time window / DRX cycle). Such alignment of time windows / DRX cycles may allow the WTRU to minimize the number of wake-up instances and maximize the sleep duration, such that both PRS measurements and SRSp transmission may be performed by the WTRU on short and / or aligned time windows / DRX cycles. When performing such aligned PRS reception and / or SRSp transmission, the WTRU may perform one or more of the following: determine an aligned time window / DRX cycle (e.g., based on PRS and / or SRSp configuration information); determine a PRS and / or SRSp configuration to be applied based on a preconfigured time window / DRX cycle; transmit an indication to the network requesting configuration and / or triggering of an aligned time window / DRX cycle; or receive an indication from the network indicating configuration and / or triggering of a time window / DRX cycle for aligned DL and UL positioning.

[0339] In order to apply in-band resources for DL-PRS and UL-SRSp transmission, the WTRU may use DL-PRS resources and / or UL-SRSp resources. The DL-PRS resources and / or UL-SRSp resources may be associated with similar frequency bands and / or resource pools during transmission and / or reception in the INACTIVE / IDLE state. The use of similar frequency bands within the same frequency band / BWP may be intended to minimize the amount of bandwidth that the WTRU may be allowed to use during the INACTIVE / IDLE state and / or to minimize power consumption in the WTRU. When performing DL-PRS measurements and / or UL-SRSp transmissions in the INACTIVE / IDLE state, the WTRU may use the same / similar center frequency for PRS and / or SRSp. Such use may improve power savings at the WTRU by avoiding re-tuning to a different center frequency when SRSp transmission is performed after PRS reception, and vice versa.

[0340] If inter-band resources are applied for DL-PRS and UL-SRSp transmissions, the WTRU may be configured with one or more FR2 bands for PRS and SRSp configuration / resources for performing DL and UL positioning. When PRS measurements made by the WTRU indicate poor link quality or high path loss (e.g., RSRP of PRS is below a threshold), the WTRU may (e.g., in this case) switch to using SRSp configuration and / or resources in the FR1 band to mitigate link-related issues. When switching to SRSp configuration in the FR1 band, the WTRU may use lower Tx power during SRSp transmission. Such switching between FR2 and FR1 bands may be configured and / or applied by the WTRU when in coverage / power limited scenarios and / or when operating in INACTIVE / IDLE states.

[0341] If in low power operation (e.g., INACTIVE / IDLE state), the WTRU may be configured to perform DL and UL positioning based on triggering events. In an example, when operating in the INACTIVE / IDLE state, the WTRU may be configured by the network to perform DL and UL (e.g., multi-RTT) positioning via DL-PRS measurements and via UL-SRSp transmissions to one or more TRPs based on detection of a pre-configured positioning triggering event. Such positioning triggering events may include one or more of the following: time events (e.g., timer expiration, periodic events); area events (e.g., events triggered when entering a new area / cell); or mobility events (e.g., speed, trajectory change).

[0342] When the WTRU is in the INACTIVE state and / or when (e.g., only when) MO-SDT is supported, the WTRU may trigger the SDT procedure at least twice for one or more of the following: for transmitting an initial request message to the network (e.g., LMF) to trigger DL and UL based positioning based on the detection of one or more events, or for transmitting a measurement report to the network (e.g., after performing PRS measurements (e.g., arrival time of PRS, RSRP) and SRSp transmission). When the WTRU is in the IDLE state, the WTRU may perform a RACH to transition to the CONNECTED state, or transmit UL data using a UL resource grant (e.g., received in Msg 2) or a pre-configured UL resource (PUR) (e.g., at each time instance that the WTRU intends to transmit (e.g., any) request message, indication and / or report to the network). Such procedures in the INACTIVE / IDLE state may result in high signaling overhead, high latency and / or high power consumption.

[0343] When operating in the INACTIVE / IDLE state, the WTRU may send an initial request message (e.g., for reporting a positioning triggering event) to the network (e.g., gNB) in an initial access message (e.g., in Msg 1, Msg3, Msg A, PRACH preamble). In an example, the initial access message may include an indication to forward the request to the LMF to initiate a positioning process (e.g., to trigger DL and UL based positioning). In an example, the initial access message may allow the WTRU to transmit (e.g., quickly transmit) a request message / indication (e.g., any request message / indication) to the network and / or eliminate the overhead for sending / receiving (e.g., additional) signaling (e.g., event reporting ACK / NACK feedback) or latency for transitioning to the CONNECTED state.

[0344] If an initial request message is transmitted (e.g., via an initial access message and / or SDT), if in an INACTIVE / IDLE state, the WTRU may perform one or more of the following: receive auxiliary data, use pre-configured auxiliary data, receive one or more SRSp configurations / resources for UL-SRSp transmission; or receive an indication triggering PRS measurement and / or SRSp transmission.

[0345] To receive the assistance data, the assistance data may include one or more PRS configurations / resources for DL-PRS measurements. Such assistance data may be received when the WTRU transmits an indication in an initial request message requesting assistance data. Such assistance data may be received if the preconfigured assistance data (e.g., any preconfigured assistance data) in the WTRU is no longer valid (e.g., due to timer expiration, validity area expiration).

[0346] To use preconfigured assistance data, the preconfigured assistance data may include (e.g., any) PRS configurations and / or resources for DL-PRS measurements. Such preconfigured assistance data may be used by the WTRU if the WTRU determines that it is valid for use during PRS measurement. The WTRU may use such preconfigured assistance data if an indication is received from the network. The indication from the network may indicate the use of one or more preconfigured PRS configurations (e.g., configuration IDs).

[0347] In order to receive one or more SRSp configurations / resources for UL-SRSp transmission, the WTRU may receive such SRSp configurations or an indication of using a pre-configured SRSp configuration (e.g., an ID of the SRSp configuration) via an initial access message, an LPP message, an RRC message (e.g., using MT-SDT), a MAC CE, or a DCI.

[0348] To receive an indication regarding triggering PRS measurement and / or SRSp transmission, such indication may be received by the WTRU via an initial access message (e.g., Msg 2, Msg 4, Msg B) or MT-SDT. Such indication may include one or more of an LPP message (e.g., a request for location information, an event report ACK), an RRC message, a MAC CE, or a DCI. If the WTRU is configured with one or more types of SRSp, including an aperiodic SRSp, a semi-persistent SRSp, and / or a periodic SRSp, the WTRU may receive a trigger indication via a DCI, a MAC CE, an RRC, or a paging message (e.g., indicating the type of SRSp (e.g., ID)).

[0349] The PRS / SRSp configuration and / or indication / trigger message may be received by the WTRU in a paging message or as part of a paging message. In an example, the WTRU may receive (e.g., in a paging message or during a paging occasion) an indication of the WTRU ID (e.g., P-RNTI) and / or an indication / trigger message for SRSp transmission in the PDCCH. The WTRU may monitor the PDCCH and / or PDSCH to receive the SRSp / PRS configuration and / or indication / trigger message in a paging message and / or in a DL reception (e.g., a subsequent DL reception). In an example, the DL reception may include MT-SDT. In an example, the WTRU may receive the PRS / SRSp configuration and / or indication / trigger message in a wake-up signal (WUS).

[0350] Upon receiving the PRS / SRSp configuration and / or indication, the WTRU may perform DL-PRS measurements using the PRS configuration and / or perform UL-SRSp transmission using the SRSp configuration. The WTRU may perform measurements of the time difference between the reception of the PRS and the transmission of the SRSp (e.g., WTRU Rx-Tx difference). When performing PRS measurements and / or SRSp transmissions, the WTRU may send measurement reports including PRS measurements (e.g., arrival time, RSRP), WTRU Rx-Tx difference measurements, etc. In order to send measurement reports in the INACTIVE / IDLE state, the WTRU may transmit the report in the initial access message (e.g., Msg A, Msg 3) or trigger the SDT procedure. In an example, the WTRU may transmit the report in Msg5. In an example, the WTRU may determine to transmit the SRSp and the measurement report in the same message (e.g., Msg3, Msg5, Msg A).

[0351] The WTRU may determine to perform round trip time (RTT) based positioning. When the SSB RSRP is above a preconfigured threshold, the WTRU may be preconfigured to perform RTT based positioning. The WTRU may measure the arrival time of the SSB and transmit the corresponding MsgA preamble and measurement report in Message A. The measurement report may include the WTRU Rx-Tx difference or RSRP. The WTRU Rx-Tx difference may (for example, in this case) be the difference between the arrival time between the SSBs and the transmission time of the corresponding preamble or SRSp.

[0352] Although the above 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 in various combinations with or without the other features and elements.

[0353] Although the implementations described herein may consider 3GPP specific protocols, it should be understood that the implementations described herein are not limited to such scenarios and are applicable to other wireless systems. For example, although the solutions described herein consider LTE, LTE-A, New Radio (NR) or 5G specific protocols, it should be understood that the solutions described herein are not limited to such scenarios and are also applicable to other wireless systems.

[0354] The processes described above may be implemented in a computer program, software, and / or firmware incorporated in a computer-readable medium for execution by a computer and / or a processor. Examples of computer-readable media include, but are not limited to, electronic signals (sent via a wired or wireless connection) and / or 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, built-in hard disks and removable disks), magneto-optical media, and optical media (such as compact disk (CD)-ROM disks and / or digital versatile disks (DVDs)). A processor associated with the software may be used to implement a radio frequency transceiver for a WTRU, terminal, base station, RNC, and / or any host computer.

Claims

1. A wireless transmit / receive unit (WTRU), comprising: A processor, the processor being configured to: sending a sounding reference signal for positioning (SRSp) configuration request, wherein the SRSp configuration request is sent when the WTRU is in an inactive state, and wherein the SRSp configuration request is sent in a message associated with a random access procedure; Receiving configuration information in a Radio Resource Control (RRC) Release message based on the SRSp configuration request being sent, wherein: The configuration information indicates a first SRSp configuration and a second SRSp configuration, The first SRSp configuration is associated with a first positioning area and the second SRSp configuration is associated with a second positioning area, The first positioning area is associated with a first set of cells, and the second positioning area is associated with a second set of cells, and The first SRSp configuration identifies a first set of resources associated with an SRSp transmission, and the second SRSp configuration identifies a second set of resources associated with the SRSp transmission; selecting the first SRSp configuration or the second SRSp configuration, wherein the selection is based at least on whether the location of the WTRU is within the first positioning area associated with the first SRSp configuration or within the second positioning area associated with the second SRSp configuration; and The SRSp is sent using the first SRSp configuration or the second SRSp configuration.

2. The WTRU of claim 1 , wherein: The first set of cells comprises a first set of cell IDs and the second set of cells comprises a second set of cell IDs, and wherein the first positioning area is associated with the first set of cell IDs and the second positioning area is associated with the second set of cell IDs.

3. The WTRU of claim 2, wherein: The processor is further configured to: A determination is made as to whether a cell ID is in the first set of cell IDs or in the second set of cell IDs, wherein the selecting is further based on the determination as to whether the cell ID is in the first set of cell IDs or in the second set of cell IDs.

4. The WTRU of claim 3, wherein: When the cell ID is detected as being in the first set of cell IDs, selecting the first SRSp configuration, and When the cell ID is detected as being in the second cell ID set, the second SRSp configuration is selected.

5. The WTRU of claim 1 , wherein: The processor is further configured to: The first SRSp configuration or the second SRSp configuration that is not selected is deactivated.

6. The WTRU of claim 1 , wherein: The sending of the SRSp is performed during the inactive state.

7. A method associated with a wireless transmit / receive unit (WTRU), the method comprising: sending a sounding reference signal for positioning (SRSp) configuration request, wherein the SRSp configuration request is sent when the WTRU is in an inactive state, and wherein the SRSp configuration request is sent in a message associated with a random access procedure; Based on the SRSp configuration request being sent, receiving configuration information in an RRC release message, wherein: The configuration information indicates a first SRSp configuration and a second SRSp configuration, The first SRSp configuration is associated with a first positioning area and the second SRSp configuration is associated with a second positioning area, The first positioning area is associated with a first set of cells, and the second positioning area is associated with a second set of cells, and The first SRSp configuration identifies a first set of resources associated with an SRSp transmission, and the second SRSp configuration identifies a second set of resources associated with the SRSp transmission; selecting the first SRSp configuration or the second SRSp configuration, wherein the selection is based at least on whether the location of the WTRU is within the first positioning area associated with the first SRSp configuration or within the second positioning area associated with the second SRSp configuration; and The SRSp is sent using the first SRSp configuration or the second SRSp configuration.

8. The method according to claim 7, wherein: The first set of cells comprises a first set of cell IDs and the second set of cells comprises a second set of cell IDs, and wherein the first positioning area is associated with the first set of cell IDs and the second positioning area is associated with the second set of cell IDs.

9. The method according to claim 8, further comprising: A determination is made as to whether a cell ID is in the first set of cell IDs or in the second set of cell IDs, wherein the selecting is further based on the determination as to whether the cell ID is in the first set of cell IDs or in the second set of cell IDs.

10. The method according to claim 9, wherein: When the cell ID is detected as being in the first set of cell IDs, selecting the first SRSp configuration, and When the cell ID is detected as being in the second cell ID set, the second SRSp configuration is selected.

11. The method according to claim 7, further comprising: The first SRSp configuration or the second SRSp configuration that is not selected is deactivated.

12. The method according to claim 7, wherein: The sending of the SRSp is performed during the inactive state.

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