Support for low power high precision positioning

Abstract

Systems, methods, and means for supporting low power high accuracy positioning (LPHAP) are described herein. 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 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 cell ID set, and the second positioning area may include a second cell ID set. The first SRSp configuration may be activated, and the second SRSp configuration may be deactivated.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 410,967, filed September 28, 2022, U.S. Provisional Patent Application No. 63 / 395,233, filed August 4, 2022, U.S. Provisional Patent Application No. 63 / 335,341, filed April 27, 2022, and U.S. Provisional Patent Application No. 63 / 308,405, filed February 9, 2022, the disclosures of which are incorporated by reference in their entireties herein. [Background technology]

[0002] Mobile communications using wireless communications continue to evolve. The fifth generation of mobile communications radio access technology (RAT) may be referred to as 5G new radio (NR). The previous (conventional) generation of mobile communications RAT may be, for example, fourth generation (4G) long term evolution (LTE). Summary of the Invention

[0003] SUMMARY Described herein are systems, methods, and instrumentalities that may be relevant to supporting low power high accuracy positioning (LPHAP).

[0004] 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 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 cell ID set, and the second positioning area may include a second cell ID set. The first SRSp configuration may be activated, and the second SRSp configuration may be deactivated.

[0005] The WTRU may transmit the first SRSp using the first SRSp configuration. In an embodiment, the WTRU may transmit the first SRSp based on detecting a cell ID that is in the first cell ID set. The first SRSp may be transmitted during low power operation (e.g., INACTIVE operation / state or IDLE operation / state) (e.g., based on receiving an RRCRelease message). The WTRU may select (e.g., detect) the second cell. In an embodiment, the WTRU may select (e.g., detect) the second cell based on the WTRU detecting a cell ID of the second cell.

[0006] The WTRU may determine that the second cell is within the second positioning area. In an example, the WTRU may determine that the second cell is located within the second positioning area based on the detected second cell ID being within a second cell ID set associated with the second positioning area. Based on the determination that the second cell is within the second positioning area, the WTRU may send a request to the second cell to activate a second SRSp configuration.

[0007] The WTRU may receive an indication to activate the requested second SRSp configuration or an indication to activate the third SRSp configuration (e.g., from the second cell). The indication to activate may be received in a message from the second cell (e.g., in an RRCResume message, an RRC reconfiguration message, or a MAC control element (MAC CE)). The WTRU may send an indication to deactivate the first SRSp configuration (e.g., when sending the request to activate the second SRSp configuration or in a separate indication request). The WTRU may transmit the 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]

[0008] [Figure 1A] FIG. 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] FIG. 1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system shown in FIG. 1A, according to one embodiment. [Figure 1C] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system shown in FIG. 1A, according to one embodiment. [Figure 1D] FIG. 1D is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communications system shown in FIG. 1A, according to one embodiment. [Diagram 2] FIG. 2 illustrates a WTRU in INACTIVE state selecting a positioning area specific SRSp configuration to perform SRSp transmission. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0010] 1A, communications 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, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station" and / or "STA," may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, wireless paging, mobile phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (loT) devices, watches or other wearable head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., for remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated processing chain context), consumer electronics devices, devices operating in commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c, and 102d may be referred to interchangeably as a UE.

[0011] 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 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, etc. Although the base stations 114a, 114b are each illustrated as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

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

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

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

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

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

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

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

[0019] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as an office, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology, such as IEEE 802.11, to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology, such as IEEE 802.15, to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may establish a picocell or a femtocell using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 via the CN 106 / 115.

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

[0021] The CN 106 / 115 may also act 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 providing plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using common communication protocols, such as the transmission control protocol (TCP), the user datagram protocol (UDP), and / or the internet protocol (IP) of the TCP / IP Internet protocol suite. The networks 112 may include wired 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 use the same RAT as the RANs 104 / 113 or a different RAT.

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

[0023] 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1B, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0024] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although FIG. 1B illustrates the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

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

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

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

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

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

[0030] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding a current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) over the air interface 116 and / or determine the location of the WTRU 102 based on the timing of signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by way of any suitable location determination method while remaining consistent with an embodiment.

[0031] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, which may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0047] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter-type control / machine-type communication, such as MTC devices in macro coverage areas. MTC devices may have limited capabilities, including certain capabilities, for example, support for (e.g., support only for) certain and / or limited bandwidths. MTC devices may include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0048] WLAN systems that may support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that may be designated as a primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be configured and / or limited by the STAs among all STAs operating in the BSS that support the smallest bandwidth operating mode. In an 802.11ah embodiment, the primary channel may be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only) the 1 MHz mode, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) configuration may depend on the status of the primary channel. For example, if the primary channel is busy due to a STA (that only supports 1 MHz mode of operation) transmitting to the AP, the entire available frequency band may be considered busy even though most of the frequency band may remain inactive and available for use.

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

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

[0051] The RAN 113 may include gNBs 180a, 180b, 180c, although it will be understood that the RAN 113 may include any number of gNBs while remaining consistent with the embodiments. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may transmit and / or receive wireless signals to and from the WTRU 102a, for example, using multiple antennas. In one embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or gNB 180c).

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

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

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

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

[0056] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may function as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. Network slicing may be used by the AMF 182a, 182b to customize the CN support of the WTRUs 102a, 102b, 102c based on the type of service utilizing the WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, 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.

[0057] The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 115 via an N11 interface. The SMFs 183a, 183b may also be connected to the UPFs 184a, 184b in the CN 115 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b and configure the routing of traffic through the UPFs 184a, 184b. The SMFs 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.

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

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

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

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

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

[0063] References herein to a timer may refer to determining a time or determining a period of time. References herein to a timer expiry may refer to determining that a time has occurred or that a period of time has expired. References herein to a timer may refer to time, a period of time, tracking time, tracking a period of time, etc. References herein to a timer expiry may refer to determining that a time has occurred or that a period of time has expired.

[0064] SUMMARY Described herein are systems, methods, and means that may be associated with supporting low power high precision positioning (LPHAP).

[0065] The WTRU may receive configuration information from the 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 cell ID set, and the second positioning area may include a second cell ID set. The first SRSp configuration may be activated, and the second SRSp configuration may be deactivated.

[0066] The WTRU may transmit the first SRSp using the first SRSp configuration. In an embodiment, the WTRU may transmit the first SRSp based on detecting a cell ID that is in the first cell ID set. The first SRSp may be transmitted during low power operation (e.g., INACTIVE operation / state or IDLE operation / state) (e.g., based on receiving an RRCRelease message). The WTRU may select (e.g., detect) the second cell. In an embodiment, the WTRU may select (e.g., detect) the second cell based on the WTRU detecting a cell ID of the second cell.

[0067] The WTRU may determine that the second cell is within the second positioning area. In an example, the WTRU may determine that the second cell is located within the second positioning area based on the detected second cell ID being within a second cell ID set associated with the second positioning area. Based on the determination that the second cell is within the second positioning area, the WTRU may send a request to the second cell to activate a second SRSp configuration.

[0068] The WTRU may receive an indication to activate the requested second SRSp configuration or an indication to activate the third SRSp configuration (e.g., from the second cell). The indication to activate may be received in a message from the second cell (e.g., in an RRCResume message, an RRC reconfiguration message, or a MAC Control Element (MAC CE)). The WTRU may send an indication to deactivate the first SRSp configuration (e.g., when sending the request to activate the second SRSp configuration or in a separate indication request). The WTRU may send the second SRSp using the SRSp configuration indicated by the second cell (e.g., the requested second SRSp configuration or the third SRSp configuration).

[0069] The WTRU may perform the LPHAP by operating in a measurement mode and / or an estimation mode. The WTRU may operate in a positioning estimation mode. The WTRU may send capability or assistance information for the estimation mode operation. The WTRU may receive assistance data for the LPHAP operation. The WTRU may switch between different positioning modes based on a switching criterion. The WTRU may perform the LPHAP when triggered by a paging message. The WTRU may send information about the LPHAP operation to the network.

[0070] An embodiment for supporting downlink (DL) based LPHAP is provided herein. If the WTRU supports LPHAP, it may use DL based positioning to mitigate positioning errors. The WTRU may perform LPHAP based on location dependent configuration or resources. The WTRU may use DL based positioned configuration information based on telecommunication relay service (TRS) reception. The WTRU may perform prediction of the WTRU's location to compensate for reduced DL measurements.

[0071] An embodiment for supporting uplink (UL)-based LPHAP is provided herein. The WTRU may perform uplink sounding reference signal for positioning (UL-SRSp) transmission for LPHAP based on the UL configured positioning area. The WTRU may perform UL-based LPHAP based on location-dependent configuration or resources. The WTRU may use common SRSp resources based on sensing. The WTRU may change or switch between SRSp configurations to support UL-based LPHAP based on detection of a triggering event. The WTRU may transmit SRSp based on detection of a location within a preconfigured positioning area. The WTRU may transmit SRSp based on detection of a transmission (Tx) scheduled time occasion and a triggering event.

[0072] An embodiment for supporting positioning using Mobile Terminated Small Data Transmission (MT-SDT) is provided herein. The WTRU may be configured with MT-SDT to support positioning in low power operation (e.g., INACTIVE / IDLE state / operation / mode). The WTRU may receive indications / information regarding positioning via MT-SDT, for example, when operating in Radio Resource Control (RRC) INACTIVE / IDLE mode. The WTRU behavior / action associated with the location may be based on whether MT-SDT is configured or started. The WTRU may determine and send to the network an indication on attributes of expected DL positioning information based on the configured MT-SDT. The WTRU may receive positioning information in DL transmissions based on a data volume threshold configured for MT-SDT. The WTRU may send indications / information on the RRC state and / or MO-SDT / MT-SDT configuration to a location management function (LMF) to support the associated positioning procedure. The WTRU may receive instructions to use the MT-SDT configuration during mobility. The WTRU may receive assistance 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 a periodicity of a discontinuous reception (DRX) cycle. The WTRU may determine a mode in which to report measurements in the INACTIVE / IDLE state.

[0073] Examples for supporting DL and UL based LPHAP are provided herein. The WTRU may be configured to perform DL and UL positioning when in low power operation (e.g., INACTIVE / IDLE state / operation / mode) based on a trigger event. The WTRU may send positioning information to the network when operating in an INACTIVE state. The WTRU may send an indication to the network to assist in predicting the WTRU's location when operating in an INACTIVE state. The WTRU may select a positioning area specific SRSp configuration based on the positioning area in which the WTRU is located. The WTRU may send a request to update the validity condition of the SRSp configuration. The WTRU may select an SRSp configuration based on detectable TRPs. The WTRU may select an SRSp configuration based on expected measurement accuracy in the positioning area in which the WTRU is located.

[0074] In low power high accuracy positioning (LPHAP) use cases (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 extended periods of time (e.g., 6 months to 1 year without charging / replacing the battery). It may be desirable (e.g., for power conservation) to minimize signaling overhead and the frequency of reporting positioning information / measurements to the network or network devices. When tracking the location of the WTRU, high positioning accuracy (e.g., horizontal accuracy of less than 1 m) may be achieved. For example, high positioning accuracy may be achieved by minimizing signaling overhead and the frequency of reporting positioning information / measurements to the network, and by using interpolation techniques to estimate the WTRU location information. Interpolating WTRU location information between reports (e.g., the WTRU may send reports less frequently by including a prediction) may leverage the persistence concept of the LPHAP, where a location service (LCS) client / application may tolerate lost or no positioning reports or information. In the LPHAP, the positioning of the WTRU may be determined relative to an expected orbit. This may be desirable, for example, when the WTRU is mobile (e.g., attached to an asset, robot, etc.).

[0075] The embodiments provided herein support positioning during low power operation (e.g., INACTIVE / IDLE states / modes / operation) and during WTRU mobility, which may result in balancing the trade-off between achieving high accuracy and high power savings.

[0076] The WTRU may be pre-configured with positioning sounding reference signal (SRSp) / positioning reference signal (PRS) configurations to use during INACTIVE / IDLE states based on knowledge of the orbit the WTRU is expected to use (e.g., at a factory floor). For UL-based positioning, the pre-configured SRSp may include a default SRSp configuration (e.g., low bandwidth (BW)) and / or a high accuracy SRSp configuration (e.g., high BW). The WTRU may select an SRSp configuration, for example, 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., list of cells / TRPs), radio conditions, or positioning QoS (e.g., whether an expected accuracy level is achieved). Power savings at the WTRU may be achieved by minimizing the occasions, durations, and bandwidths for transmitting one or more SRSp (UL-based) and / or for performing PRS measurements / reports (DL-based). Power savings may be achieved (e.g., may also be achieved) by not transmitting one or more SRSps / measuring PRSs (e.g., if accuracy requirements cannot be met) and by using prediction / interpolation techniques.

[0077] An example of SRSp transmission based on scheduled Tx occasions is provided herein. For scheduled SRSp transmission, the WTRU may be configured with one or more scheduled Tx occasions for transmitting SRSp and SRSp configurations associated with the Tx occasions. The WTRU may select a first SRSp configuration (e.g., a high periodicity configuration) for SRSp transmission that results in high accuracy during an initial phase of positioning (e.g., when starting to move from a stationary position) or if it detects an event indicating low accuracy. The WTRU may select (e.g., then select) a second SRSp configuration (e.g., a low periodicity configuration) in a positioning phase (e.g., a subsequent positioning phase) if accuracy requirements are met and / or remain stable. If it detects an interruption event (e.g., a change in mobility state, receiving a DL indication), the WTRU may reset the SRSp transmission procedure based on the type of event (e.g., this may help with positioning accuracy and power savings).

[0078] The WTRU may receive configuration information. The configuration information may include one or more SRSp configurations. The SRSp configurations 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 include) one or more SRSp Tx occasions (e.g., T0, T1, T2) for transmitting one or more SRSp. The Tx occasions (Ti) may be associated with the SRSp configurations. During an 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-T0). The WTRU may select an SRSp configuration associated with the current SRSp Tx occasion (e.g., the WTRU may select a first SRSp configuration (high periodicity) if the current SRSp Tx occasion is T0, and may select a second SRSp configuration (low periodicity) if the current SRSp Tx occasion > T0). The WTRU may send an indication to the network that may indicate the start of SRSp transmission (e.g., when the current Tx occasion is T0). The WTRU may transmit the SRSp using resources in the selected SRSp configuration. If an event (e.g., an interruption event) is detected (e.g., reception of DL data / indication, change in mobility state), the WTRU may stop the timer and SRSp transmission. If the event (e.g., a second event) is a semi-static event (e.g., reception of periodic data), the WTRU may restart the timer and resume SRSp transmission using the current SRSp configuration (e.g., the SRSp configuration associated with the closest Tx occasion). If the event (e.g., the second event) is a dynamic event (e.g., receipt of Ultra-Reliable and Low Latency Communication (URLLC) data, a change in mobility state), the WTRU may perform one or more of: resetting a timer (e.g., to T0), sending an indication to the NW indicating a reset and start of SRSp transmission, or transmitting SRSp using resources in the SRSp configuration associated with the SRSp Tx time occasion (e.g., T0).If an event (e.g., a second event) corresponds to an abort of the transmission (e.g., receipt of a DL indication to stop SRSp transmission), the WTRU may stop the timer and SRSp transmission. If no event (e.g., a second event) is detected, the WTRU may stop SRSp transmission upon expiration of the timer, for a configured duration, or until the start of the next Tx occasion.

[0079] Examples of SRSp transmission based on configured positioning areas are provided herein. For area-dependent transmission, the WTRU may transmit SRSp in a preconfigured positioning area (e.g., coverage area of ​​a set of TRPs) using an associated SRSp configuration. The WTRU may select a preconfigured SRSp configuration based on the trajectory the WTRU is expected to follow and based on the expected accuracy of measurements achieved at the corresponding TRPs. If the expected accuracy requirements are not met at a TRP, the WTRU may use SRSp associated with some TRPs that can meet the accuracy (e.g., exceptional SRSp configurations with high BW).

[0080] The WTRU may receive configuration information. The configuration information may include one or more SRSp configurations including resources in at least a low BW SRSp configuration and a high BW SRSp configuration (e.g., an exceptional SRSp configuration). The configuration information may include (e.g., may also include) one or more sets of TRPs (e.g., cell IDs). The one or more sets of TRPs may be associated with one or more SRSp configurations (e.g., each set of TRPs may be associated with an SRSp configuration) (e.g., the TRPs in a set may be configured by the LMF to perform SRSp measurements). The configuration information may include (e.g., may also include) a threshold for a minimum number of TRPs required to meet an accuracy requirement. The WTRU may perform SSB / TRS measurements to detect one or more transmission reception points (TRPs) and determine radio conditions associated with the detected TRPs (e.g., using RSRP measurements of RSs in a spatial relationship with the SRSp). If the detected TRP matches a configured set of TRPs and / or if the number of detected TRPs with good reference signal received power (RSRP) is greater than a threshold for the minimum number of TRPs required to meet an accuracy requirement, the WTRU may select a low BW SRSp configuration associated with the detected TRP and may transmit the SRSp using resources in the low BW SRSp configuration.If the detected TRP matches the configured set of TRPs and the number of detected TRPs with good RSRPs is less than a threshold, the WTRU may perform one or more of: determining a high BW SRSp configuration (e.g., an exceptional SRSp configuration) associated with the detected TRP with good RSRP based on pre-configuration and / or receiving a positioning system information block (SIB); sending an indication to the gNB (e.g., using the RACH-SDT) indicating an ID of the detected TRP and a request to activate the high BW SRSp configuration (e.g., the exceptional SRSp configuration); or transmitting the SRSp using resources in the high BW SRSp configuration (e.g., the exceptional SRSp configuration) (e.g., after receiving an indication from the gNB). If the detected TRP does not match the configured set of TRPs, the WTRU may send an indication to the gNB to request an updated SRSp configuration and may transmit the SRSp using resources in the updated SRSp configuration (e.g., after receiving an updated SRSp configuration from the gNB).

[0081] Examples of downlink positioning, examples of uplink positioning, and examples of downlink and uplink positioning are provided herein.

[0082] In an embodiment of downlink positioning, the WTRU may receive one or more PRSs from one or more TRPs. The WTRU may observe multiple reference signals and measure the time difference of arrival between the PRSs (e.g., a pair of PRSs). The WTRU may (e.g., then) send the measured reference signal time difference (RSTD) to the LMF. The WTRU may send (e.g., in addition to) the measured RSRPs for the PRSs (e.g., the measured RSRPs for each PRS of one or more PRSs). Based on the returned measurements, the LMF may perform positioning of the WTRU. The WTRU may report the RSRPs for DL ​​angle-based positioning.

[0083] The LMF is a non-limiting example of a node or entity (e.g., a network node or entity) that may be used for or to support positioning. In an embodiment, another node (e.g., any other node or entity) may be used instead of the LMF.

[0084] In an uplink positioning embodiment, the WTRU may send an SRS for positioning (e.g., configured by the RRC) to a Reception Point (RP). For a timing-based method, the TRP may measure the RTOA of the received SRS and report the measurement to the LMF. The TRP may report the RSRP for the SRS. For an angle-based uplink positioning method, the RP may measure the angle of arrival and report it to the LMF.

[0085] In an uplink and downlink positioning embodiment, 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 report the measured RSRP for the PRS (e.g., it may also report it). In the TRP, the Rx-Tx difference between the received SRS and the transmitted PRS may be calculated.

[0086] The following positioning examples are provided herein.

[0087] A "DL positioning embodiment" may refer to any positioning embodiment that uses a downlink reference signal, such as a PRS. The WTRU may receive one or more reference signals from a TP and may measure DL RSTD and / or RSRP. An example of DL positioning is DL-AoD or DL-TDOA positioning.

[0088] A "UL positioning embodiment" may refer to any positioning embodiment that uses an uplink reference signal such as SRS for positioning. The WTRU may transmit SRS to multiple RPs, and the RPs may measure UL RTOA and / or RSRP. UL positioning embodiments may include UL-TDOA or UL-AoA positioning.

[0089] A "DL and UL positioning embodiment" may refer to a positioning embodiment that may use uplink and downlink reference signals for positioning. The WTRU may transmit SRS to multiple TRPs and the gNB may measure the Rx-Tx time difference. The gNB may measure the RSRP for the received SRS. The WTRU may measure the Rx-Tx time difference for PRS transmitted from multiple TRPs. The WTRU may measure the RSRP for the received PRS. The Rx-TX difference and / or the 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 transmitted by the TRP and the transmission time of the reference signal transmitted from the WTRU. An example of DL and UL positioning is multi-RTT positioning.

[0090] The "network" may include an AMF, an LMF, a base station, a TRP, or a gNB in ​​the NG-RAN.

[0091] Positioning embodiments for DL-PRS measurements in RRC CONNECTED may allow intra-gNB mobility (within the coverage areas of TRPs belonging to the same gNB) (e.g., limited levels of intra-gNB mobility) and / or inter-gNB mobility (e.g., for scenarios where the same PRS configuration is used by multiple gNBs). Reporting of measurements or location information to the LMF may be supported via the serving gNB / cell.

[0092] Examples herein provide WTRU-based and LMF-based (e.g., WTRU-assisted) positioning for RAT-dependent and RAT-independent positioning. WTRU behaviors and examples for supporting low power high accuracy positioning (LPHAP) (including, for example, examples related to configuration, transmission, measurement and reporting, low latency WTRU, high power savings, and high accuracy) may be provided herein. Examples of using LPP to determine WTRU positioning information using LPHAP may be provided herein.

[0093] In an embodiment of DL-based positioning, the WTRU may perform measurements of resources associated with DL-PRS. The WTRU may send measurement reports to the LMF based on assistance data provided by the network. In an embodiment of UL-based positioning, the WTRU may be configured with SRS (SRSp) resources for positioning via RRC signaling. The SRSp transmission by the WTRU may be received (e.g., may then be received) by different TRP / gNBs in the network to perform positioning measurements and report the measurements to the LMF, which determines the location of the WTRU. When the WTRU enters a different coverage area that includes a set of TRP / gNBs (e.g., an updated / new TRP / gNB), the WTRU may be provided with a PRS / SRSp configuration (e.g., an updated / new PRS / SRSp configuration). This may result in resource waste and power inefficiency, as positioning embodiments (e.g., receiving configuration, transmitting SRSp, measuring PRS) may be performed regardless of the WTRU's power saving mode, WTRU mobility attributes (e.g., stationary or moving slowly), and / or achievable positioning QoS (e.g., accuracy, latency).

[0094] Provided herein are embodiments that support positioning during low power operation (e.g., INACTIVE / IDLE state / operation / mode operation) and WTRU mobility that may result in balancing the trade-off between achieving high accuracy and high power savings.

[0095] A sounding reference signal for positioning may be denoted as "SRSp". PRS or SRS as used herein is not limited to an RS used for positioning. The embodiments herein may apply to or be used with (e.g., any) DL or UL reference signal. Note that "SRSp" may refer to an SRS signal / transmission used for positioning herein. Resources for SRS for positioning (SRSp) may be defined (e.g., signaled) by RRC. SRS resource sets and SRS resources configured for positioning may be specified. In this specification, "SRS for positioning" or "SRS" may include at least one of an SRS that may be configured under SRS-PosResourceSet and SRS-PosResource, an SRS that may 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 uplink reference signal associated for positioning, a demodulation reference signal (DM-RS) for the uplink, or a phase tracking reference signal (PTRS) for the uplink.

[0096] An example of a positioning configuration is provided herein. 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 of the positioning examples used (e.g., DL-TDOA, UL-TDOA, DL-AoD, UL-AoA, Multi-RTT), PRS configuration, SRSp configuration, uplink resources for reporting 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 positioning measurement quality, and a positioning operation mode (e.g., starting positioning operation mode). The PRS resource configuration may include at least one of a PRS resource ID, a PRS sequence ID or other ID used to generate the PRS sequence, a PRS resource element offset, a PRS resource slot offset, a PRS symbol offset, PRS QCL information, a PRS resource set ID, a list of PRS resources in the resource set, the number of PRS symbols, a muting pattern for the PRS, muting parameters such as a repetition factor, a muting option, a PRS resource power, a periodicity of the PRS transmission, spatial direction information of the PRS transmission (e.g., beam information, transmit angle), spatial direction information of the UL RS reception (e.g., beam ID used to receive the UL RS, arrival angle), a frequency layer ID, a TRP ID, or a PRS ID.

[0097] The SRSp resource configuration may include at least one or more of a resource ID, a comb offset value, a cyclic shift value, a starting position in the frequency domain, a number of SRSp symbols, a shift in the frequency domain for the SRSp, a frequency hopping pattern, a type of SRSp (e.g., aperiodic, semi-persistent, or periodic), a sequence ID used to generate the SRSp or other ID used to generate the SRSp sequence, spatial relationship information indicating which reference signal the SRSp is spatially related to, a resource set ID, a list of SRSp resources within a resource set, transmit power related information, path loss reference information which may include an index for SSB, CSI-RS, or PRS, a periodicity of SRSp transmission, spatial direction information of SRSp transmission (e.g., beam information, transmission angle), or spatial direction information of DL RS reception (e.g., a beam ID and / or arrival angle used to receive DL RS).

[0098] 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 the PRS. The TRP transmitting the PRS may be identified by the TRP ID. The TRP ID may belong to a cell identified by the cell ID. The WTRU may be configured with timing information such as an SFN offset for the PRS or SRSp transmission. The offset may prevent the WTRU from receiving overlapping PRS in the time domain.

[0099] An example for supporting a general LPHAP is provided herein.

[0100] The WTRU may implement the 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 (e.g., low power, high positioning accuracy) associated with the LPHAP service.

[0101] WTRU operation in a measurement mode may refer to one or more of DL-based positioning, UL-based positioning, DL+UL-based positioning, areas and / or time occasions that may be associated with different reference locations and / or reference time instances at which the WTRU may perform measurements and / or transmissions, or the WTRU may receive areas and / or time occasions from the network or an application.

[0102] 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 time occasions based on measurements made by the WTRU. Examples of DL-based positioning may include DL-TDoA, DL-AoD, etc.

[0103] 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 time occasions based on measurements made by the TRP / gNB in ​​the network. Examples of UL-based positioning may include UL-TDoA, UL-AoA, etc.

[0104] In the case of DL+UL based positioning, a combination of DL and UL based positioning (eg, a multi-RTT method) may be implemented to determine the location of the WTRU in different areas and / or at different time occasions.

[0105] For a WTRU receiving the area and / or time occasion from a network or application, the WTRU may receive the area and / or time occasion from the network or application, for example, as configuration / assistance information, in some cases. The network may correspond to one or more of: one or more base stations (e.g., serving gNBs or non-serving gNBs in an NG-RAN), a TRP, an LMF, an AMF, or an LCS client associated with the one or more base stations.

[0106] A WTRU operating in an estimation mode may refer to one or more of the following: A WTRU operating in an estimation mode may perform limited measurements of DL signals (e.g., DL-PRS, CSI-RS) or no measurements. A WTRU operating in an estimation mode may perform limited transmissions of UL signals (e.g., SRSp, SRS) or no transmissions of UL signals (e.g., SRSp, SRS). A WTRU operating in an estimation mode may refer to the WTRU / NW using prediction / extrapolation techniques to determine the location of the WTRU in a future area and / or time occasion (e.g., p(T2)=p(T1)+v(T2-T1), where p is the location of the WTRU and v is the velocity of the WTRU). WTRU operation in estimation mode may refer to a WTRU / NW using smoothing / interpolation techniques to determine or correct the WTRU's location in a previous / past area and / or time occasion (e.g., p(T1)=p(T2)-v(T2-T1)). WTRU operation in estimation mode may refer to a WTRU using internal sensors (e.g., accelerometer, gyroscope, magnetometer) to measure the WTRU's speed, direction, orientation, and motion rate. 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 when operating in measurement mode above / below threshold). WTRU operation in estimation mode may refer to a WTRU supplementing limited PRS measurements and / or SRSp transmissions by performing sensor measurements to conserve power and / or improve positioning accuracy. WTRU operation in estimation mode may refer to the WTRU sending WTRU location information 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).

[0107] Prediction and / or smoothing techniques that may be used to estimate the WTRU's position may be based on using one or more of RAT-dependent techniques (e.g., PRS measurements and / or SRSp transmissions), RAT-independent techniques (e.g., GNSS measurements or sensor measurements), information about the WTRU's mobility state (e.g., stationary, mobile with a first speed, mobile with a second speed), or information about the WTRU's trajectory (e.g., expected WTRU locations at different time occasions).

[0108] An example may be provided of a WTRU operating in a positioning estimation mode. 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 within at least the second time window may be determined by the WTRU and / or the network based on expected changes in the WTRU's location relative to measurements made during the first time window.

[0109] During the estimation mode, the WTRU may track the movement, mobility, and / or orbit attributes of the WTRU with respect to a reference area and / or time occasion to determine the location of the WTRU. The WTRU may perform DL-PRS measurements or SRSp transmissions at an initial reference time. The WTRU may suspend (e.g., then suspend) performing measurements and / or transmissions during mobility while tracking and / or logging 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 the next reference time. The location of the WTRU at a time (e.g., any given time) may be determined or estimated (e.g., then determined or estimated) by the WTRU or the network, for example, based on measurement information at one or more reference time instances and / or tracking and / or logging information of mobility and / or orbit attributes.

[0110] With respect to operating in an estimation mode to estimate, predict, and / or smooth the WTRU's location information, a WTRU-assisted estimation mode and / or a WTRU-based estimation mode may be applied.

[0111] For the WTRU-assisted estimation mode, the WTRU may send measurement and / or mobility attribute (e.g., speed, direction) reports to the network periodically, aperiodically, or upon detection of an event trigger (e.g., possibly based on assistance data received from the network). The WTRU may transmit a UL-SRSp using a periodic, aperiodic, or semi-persistent SRSp resource configuration upon detection of an event trigger (e.g., change in radio conditions, WTRU mobility state, orbit, etc.). The location 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 or complete measurement absence). The WTRU may send information about PRS measurements, changes in orbit attributes (e.g., change in WTRU movement relative to expected orbit / location known to the network), error conditions, and / or prediction and / or smoothing information related to the WTRU's location.

[0112] For a WTRU-based estimation mode, the WTRU may receive assistance information from the network including one or more DL-PRS and / or SRSp configurations, correction information to adjust / compensate for errors in measurements, or reference areas and / or times when the WTRU may operate in a measurement mode (e.g., performing DL-PRS measurements or UL-SRSp transmissions) or an estimation mode (e.g., performing sensor measurements). The WTRU may switch between the measurement mode and the estimation mode periodically and / or when it detects an event / condition (e.g., a change in the mobility state of the WTRU, where the RSRP of a measurement goes above / below an RSRP threshold). The WTRU may estimate (e.g., then estimate) the location of the WTRU at different time instances based on at least one of the assistance information, the measurements, or the sensor tracking information. The WTRU may send one or more indications to the network when switching between the measurement mode and the estimation mode. The WTRU may send (e.g., may also send) information about at least one of the WTRU's location determined via (e.g., during) the estimation mode, the error in the estimation, the confidence level (e.g., in the estimated location), or the uncertainty in the WTRU's determined location or measurements determined during the estimation mode. The WTRU may send predicted location information (e.g., the WTRU's location in geographic coordinates or relative position) or smoothed location information (e.g., corrected location information made in the past) based on current measurements. The WTRU may associate a timestamp or a relative timestamp (e.g., the time difference between current stamps expressed in terms of milliseconds, symbols, slots, frames, or subframes) with the predicted or smoothed location information.

[0113] The WTRU may send capability and / or assistance information for estimation mode operation. In an embodiment, the WTRU may send capability and / or assistance information to the network (e.g., gNB or LMF) to operate in a positioning estimation mode if it detects one or more triggering events (e.g., as described herein). The WTRU may send the capability and / or assistance information semi-statically before and / or after initializing a positioning procedure (e.g., an LPP session) to determine the location of the WTRU, which may include operation in a measurement mode or an estimation mode (e.g., prediction). The WTRU may send the capability / assistance information dynamically or on-demand at a time after initializing the positioning procedure. The WTRU may send the capability / assistance information to the network in an LPP message (e.g., an LPP Provided Capability Information or LPP Provided Assistance Information message) or AS layer signaling / message (e.g., using one or more of the RRC, MAC CE, uplink control information (UCI), or PUSCH).

[0114] The information sent by the WTRU to the network, either as capability information (e.g., via LTE positioning protocol (LPP) capability transfer procedure, AS layer signaling / message) or assistance information (e.g., via LPP assistance data transfer procedure, AS layer signaling / message), may include one or more of the following: information about the embodiment, device attributes and / or parameters, achievable accuracy, reference location, reference time instance, and / or orbit, or power saving mode to be applied when operating in an estimation mode.

[0115] Examples that apply when operating in an estimation mode may include one or more of the following: When operating in an estimation mode, the WTRU may indicate an ability to operate in a WTRU-assisted mode and / or a WTRU-based mode in association with the estimation mode. For example, the WTRU may indicate an ability to estimate its location when operating in a WTRU-based mode with limited or no PRS measurements and / or SRSp transmissions. When operating in an estimation mode, the WTRU may indicate sensor / device information. For example, the WTRU may indicate one or more identifiers and / or information associated with sensors (e.g., gyroscope, magnetometer, accelerometer, GNSS receiver) that may be accessible by the WTRU to perform sensor measurements when operating in an estimation mode. When operating in an estimation mode, the WTRU may indicate technique / algorithm information. For example, the WTRU may indicate identifiers and / or information for positioning algorithms (e.g., dead reckoning) used with internal sensors / devices to estimate the WTRU position. When operating in an estimation mode, the WTRU may indicate prediction and / or smoothing information. For example, the WTRU may indicate IDs, information, configurations, and / or parameters related to prediction techniques and / or algorithms to be applied to predict the location of the WTRU based on limited or no measurements. Such techniques and parameters may include one or more of the following: a capability to use a neural network (NN), supported learning techniques (e.g., supervised, unsupervised, reinforcement learning), training data parameters, a (e.g., maximum) number of layers in the NN, a (e.g., maximum) number of neurons per layer, a (e.g., maximum) number of inputs / outputs / weights per neuron, or a processing latency.

[0116] Regarding the device attributes and / or parameters sent 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, if supporting an estimation mode, processing capabilities for transmit / receive, fused RF measurements, and / or sensor measurements.

[0117] For accuracy achievable information sent 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 may be achievable when operating in estimation mode and / or measurement mode. The WTRU may indicate information about timing error groups (TEGs), including, for example, WTRU Tx TEG ID, WTRU Rx TEG ID, WTRU Rx-Tx TEG ID. The WTRU may send (e.g., may also send) association information between, for example, SRSp resources and WTRU Tx TEG ID. The WTRU may indicate whether it is capable of operating 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 be) associated with different granularities including one or more of RAT dependent / independent techniques, positioning embodiments, PRS / SRSp configurations, frequency layers, resource sets / resources, beams, or sensor measurements. The WTRU may (e.g., may also) indicate a priority value and / or a preferred value associated with an accuracy level.

[0118] For reference locations, reference time instances, and / or orbit information sent from the WTRU to the network, the WTRU may provide information (e.g., identifiers) about the availability and / or accessibility to one or more reference locations associated with a positioning reference unit (e.g., WTRU, TRP, gNB, cell, NTN node, satellite) or (e.g., any) detectable landmark (e.g., possibly in proximity to the WTRU). The WTRU may (e.g., may provide), for example, a distance / range to an identified reference location. The WTRU may (e.g., may indicate) information (e.g., ID) about one or more positioning areas and / or zones (e.g., which may be associated with the coverage areas 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 a different time instance).

[0119] Information about power saving modes sent from the WTRU to the network may provide power saving modes supported by the WTRU and / or configured by the network (e.g., possibly including timing information (e.g., timestamp) of when the WTRU has previously transitioned or is expected to transition to RRC CONNECTED, RRC INACTIVE, RRC IDLE, or any other combination of power saving modes / states). The information about power saving modes may include, for example, 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) indicate priority values ​​and / or preferred values ​​associated with supported power saving modes / states (e.g., possibly along with location / area information and / or timing information where such priority / preferred values ​​may be applied).

[0120] The trigger events and / or conditions monitored by the WTRU to send capability information and / or assistance information for the LPHAP may include one or more of: receipt of an instruction or LCS / LPP request from higher layers / applications / network; detection reference location and / or time; periodicity of the trigger events and / or conditions; or changes in radio conditions or sensor measurements.

[0121] Due to receiving an indication or LCS / LPP request from higher layers / applications / network, the WTRU may send capability information or indication when triggered by an LCS client / application in the WTRU (e.g., MO-LR) or in the network (e.g., MT-LR, suspended MT-LR, NI-LR). The LCS client / application may provide the WTRU's reference time (e.g., planned location time), reference location, and / or expected orbit. The WTRU may receive the indication from the LCS client in one or more of an LCS message, an LPP message, or an AS layer signaling / channel (e.g., RRC, MAC CE, downlink control information (DCI), data, etc.). The WTRU may send capability and / or assistance information when it receives an LPP request message from the network. The request message may include a request for information related to measurements, WTRU power saving mode, orbit, reference location / time, accuracy attributes, etc.

[0122] For a detection reference location and / or time, the WTRU may send capability information and / or an indication when it detects one or more reference locations (e.g., PRU positioning areas) and / or at a reference time instance (e.g., scheduled location time).

[0123] Regarding the periodicity of the triggering events and / or conditions, the WTRU may send the capability information and / or indication periodically (e.g., possibly based on one or more periodicity values ​​configured by the network). The WTRU may send updated / new capability and / or assistance information if it detects a change (e.g., any change) in the capability and / or assistance information (e.g., with respect to a previous occasion on which the information may be sent).

[0124] For changes in radio conditions or sensor measurements, the WTRU may send capability information and / or indications when triggered by a change in radio conditions detectable at the WTRU. The WTRU may be configured to perform measurements or sensor measurements for DL-PRS / CSI-RS / SSB. The WTRU may send information when a measurement (e.g., RSRP, received signal strength indicator (RSSI), magnetic field measurements, device orientation) increases or decreases by a certain corresponding threshold.

[0125] The WTRU may send indications and / or information to the network (e.g., gNB, LMF) (e.g., possibly based on the triggering events / conditions mentioned above). The indications and / or information sent by the WTRU may include at least one of 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 to notify the start of SRSp transmission or the start of PRS measurement, or an indication of detection of a triggering event. The WTRU may send the indication in an RRC_CONNECTED, RRC_INACTIVE, or RRC_IDLE state. In an embodiment, when the WTRU is in low power operation (e.g., INACTIVE state / mode / operation), the WTRU may send the indication in the SDT using RACH or CG resources associated with the SDT. In an embodiment, if the WTRU is in IDLE state, the WTRU may send an indication in an initial access / RACH message (e.g., RRCRequest, RRCSystemInformationRequest, RRCReconfigurationRequest, or a RACH / RRC message associated with positioning). The WTRU may send an indication when it is IDLE on a RACH occasion (e.g., possibly associated with positioning). When sending an indication in INACTIVE / IDLE state, the WTRU may include flags, information and / or use resources associated with low power positioning (e.g., SDT) such that the WTRU cannot be transitioned to CONNECTED state. The WTRU may send the indication to the network when it transitions to CONNECTED state (e.g., for non-positioning or positioning related, as the case may be).

[0126] An embodiment of a WTRU receiving assistance data for LPHAP operation is provided herein. The WTRU may perform any procedures, functions, and operations associated with LPHAP when receiving assistance data associated with LPHAP and / or other positioning embodiments / methods (e.g., DL-based, UL-based, DL+UL-based, GNSS, etc.). The assistance data may be received within a positioning SIB (e.g., broadcast with a periodicity configured in the posSIB), an LPP message, or an AS layer signaling / channel (e.g., RRC, MAC CE, DCI, PDSCH, etc.).

[0127] The WTRU may receive assistance data associated with the LPHAP periodically by (via one or more of) sending a request or detecting a configured event and / or condition.

[0128] In the case of a WTRU receiving assistance data associated with an LPHAP via sending a request, the WTRU may send a request for assistance data (e.g., an LPP message or AS layer signaling) to the network indicating information, identifiers, configurations, and / or parameters associated with the LPHAP. The WTRU may receive (e.g., may then receive) the corresponding assistance data. In an embodiment, the WTRU may receive the assistance data (e.g., in an LPP message) after sending capability information and / or other indications / messages (e.g., an on-demand request, an LCS message, an LPP message, positioning information / reports, etc.).

[0129] For a WTRU that periodically receives assistance data associated with an LPHAP, the WTRU may be configured by the network to periodically receive the assistance data with a particular configured periodicity. The WTRU may request to change the periodicity for receiving the assistance data based on detection of one or more events, such as a change in the WTRU's mobility state (e.g., from stationary to mobile) or a change in orbit.

[0130] In the case of a WTRU receiving Assistance Data associated with an LPHAP upon detecting a configured event and / or condition, the WTRU may receive Assistance Data for the LPHAP (e.g., associated with a different ID) and / or other positioning methods / schemes (e.g., which may be stored by the WTRU (e.g., in the context information) and retrieved for future positioning procedures / sessions (e.g., LPP sessions)). The WTRU may (e.g., may receive) validity conditions (e.g., positioning area and / or time validity) and / or events associated with storing, using, and / or releasing the Assistance Data. The WTRU may use the pre-configured Assistance Data as long as the validity conditions are active / valid and / or an event that invalidates the pre-configured Assistance Data is not detected by the WTRU. The WTRU may receive updated / new Assistance Data if a validity condition expires and / or an event that invalidates the pre-configured Assistance Data is detected by the WTRU (e.g., based on an indication sent by the WTRU to the network reporting expiration of a validity condition, detection of an event, and / or a request for new / updated Assistance Data, as the case may be).

[0131] The assistance data received by the WTRU may include one or more of a time window / interval for the measurement mode and / or estimation mode, a measurement mode configuration (e.g., PRS configuration for LPHAP), an estimation mode configuration, a priority of the measurement and / or estimation configuration, an error threshold (e.g., to determine if accuracy requirements are met), correction information (e.g., to recover from measurement / estimation errors), or a reporting configuration.

[0132] 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 start time slot / instance, offset time relative to a reference time slot, duration, stop time slot / instance) indicating when the WTRU may operate in measurement mode (e.g., perform DL-PRS measurements or SRSp transmissions) or operate in estimation mode (e.g., perform sensor measurements, trajectory tracking). The time windows may correspond to information about when the WTRU may perform prediction / extrapolation and / or smoothing / interpolation of the WTRU's location (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's location. In an example, a first time window with a measurement interval of 10 ms may be used to perform prediction of a predicted WTRU's location 1 ms ahead. In an embodiment, a second time window with a measurement interval of 5 ms may be used to perform a prediction of the expected WTRU location 0.5 ms ahead. The WTRU may receive information about the survival time indicating a time window / interval that the LMF / LCS client / application can tolerate when there may be loss, delay, or absence of positioning reports and / or information sent by the WTRU. During the survival time, the WTRU / LMF may perform interpolation / smoothing to determine the WTRU's location at intermediate time instances between different positioning reports and / or information sent by the WTRU.

[0133] For assistance data received by the WTRU that includes a measurement mode configuration (e.g., a PRS configuration for an LPHAP), the WTRU may receive one or more PRS configurations and / or parameters (e.g., IDs) and / or SRSp configurations and / or parameters (e.g., may be associated with or intended for the LPHAP and / or power save mode operation (e.g., for use during INACTIVE / IDLE modes). The PRS / SRSp configurations may include one or more frequency layers, resources, resource sets, beams, or TRP / gNBs associated with the indicated PRS / SRSp configuration. In an embodiment, the one or more PRS / SRSp configurations for the LPHAP may include a combination of a relatively low / high number of frequency layers, bandwidths (frequency resources), periodicity, density of resources, number of beams, number of TRP / gNBs, etc. The types of PRS / SRSp configurations received by the WTRU may include aperiodic, semi-persistent, and / or periodic, along with timing information associated with the different types, such as start time / slot, periodicity, and / or stop time / slot. The WTRU may (e.g., may receive) information about one or more measurement gap configurations (e.g., IDs) that may be associated with PRS configurations to be used during the measurement mode and / or the estimation mode. Such measurement gap configurations may be activated during operation in the measurement mode and / or the estimation mode.

[0134] For assistance data received by the WTRU that includes an estimation mode configuration, the WTRU may receive trajectory information associated with the WTRU and / or another device (e.g., robot, asset, vehicle) to which the WTRU may be attached or co-located. In an embodiment, 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 embodiment, the trajectory information may include different trajectory types (e.g., straight path, left curve, right curve) that may be associated with different scheduled time instances. The trajectory information may be associated with one or more PRS / SRSp configurations (e.g., may be used by the WTRU to perform measurements and / or transmissions when it detects the corresponding locations and / or time instances indicated in the trajectory).

[0135] The WTRU may receive one or more (e.g., preconfigured) trajectories, and each trajectory or subset of trajectories may be associated with an ID and / or may receive information about which of the trajectories / subset of trajectories the WTRU is expected to use / follow (e.g., possibly at different time instances / windows). When reporting information about the actual and / or estimated trajectories the WTRU follows, the WTRU may send information about the trajectories / subset of trajectories (e.g., ID) to the network. For example, if there may be uncertainty in the current or expected trajectory (trajectory / subset of trajectories) the WTRU follows, the WTRU may determine one or more trajectories that may best match the preconfigured trajectory received from the network (e.g., possibly with respect to a location on the route, the difference between the preconfigured trajectory and the actual / expected trajectory is less than a threshold). The WTRU may indicate information about the determined trajectories (e.g., ID) to the network, possibly along with confidence / weight / probability values ​​associated with the different determined trajectories.

[0136] The WTRU may receive assistance data related to a time window that indicates when the WTRU may operate in an estimation mode. The assistance data may (e.g., may 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 upon detection of the location / time instance. This information reported by the WTRU on detection of cells / TRPs may be used to assist the network to improve the prediction accuracy of the WTRU's location.

[0137] For assistance data received by the WTRU that includes a priority of the measurement and / or estimation configuration, the WTRU may receive a priority value associated with the measurement mode and / or estimation mode. Within each mode, the WTRU may (e.g., may receive) a priority value associated with a PRS / SRSp configuration and / or orbit configuration. The WTRU may select a mode and / or associated configuration based on a priority order, and may first use the PRS / SRSp / or orbit configuration with the highest priority for measurement and / or estimation when multiple configurations are indicated / available.

[0138] For assistance data received by the WTRU that includes an error threshold (e.g., for determining whether an accuracy requirement is met), the WTRU may receive one or more error thresholds associated with the measurements (e.g., RSRP threshold, number of multipaths) and positioning QoS (e.g., accuracy, completeness, latency). The error thresholds may be used by the WTRU, for example, when determining / predicting / smoothing the location of the WTRU at different time instances to determine whether the positioning QoS requirements are met.

[0139] For assistance data received by the WTRU that includes correction information (e.g., to recover from measurement and / or estimation errors), the WTRU may receive the correction and / or compensation information to apply when operating in a measurement mode and / or estimation mode. The WTRU may (e.g., may receive) the correction and / or compensation information to apply when operating in a measurement mode and / or estimation mode when the measurement and / or estimation is invalid, when recovering from an error condition, or when operating in a measurement mode and / or estimation mode. In an embodiment, the correction information may be related to a timing / phase error (e.g., associated with a TRP / gNB and / or PRS / SRSp resource) indicating a difference between the time instances / phases when the PRS / SRSp is generated and transmitted by the TRP / gNB or the WTRU. In an embodiment, the correction information may be related to expected timing / phase errors in different positioning areas and / or time instances. The WTRU may use the corresponding correction information based on one or more of the PRS / SRSp resource, TRP / gNB, area, and time instance when performing PRS measurement, SRSp transmission, WTRU location estimation, or prediction.

[0140] For assistance data received by the WTRU that includes a reporting configuration, the WTRU may receive a reporting configuration to apply when sending information about positioning measurements and / or positioning estimation / prediction (e.g., when operating in a measurement mode and / or an estimation mode). In an embodiment, the reporting configuration may include an ID to be used (e.g., LPP ID, WTRU ID, positioning embodiment / scheme ID, power save mode ID). In an embodiment, the reporting configuration may include whether to report absolute / average / min / max values ​​associated with measurements made on a PRS (e.g., resources / beams associated with the PRS configuration) and / or measurements made on a sensor. The reporting configuration may include reporting periodicity (e.g., whether reports should be aligned with measurements and / or transmissions), offsets for start and / or end of measurements, and events the WTRU may monitor / detect in order to send a report to the network. The WTRU may send a report on the positioning measurements, estimates, predictions, and / or uncertainties if one or more of a change in radio conditions (e.g., RSRP above / below a threshold), a change in mobility state, or a change in the WTRU trajectory (e.g., the WTRU deviates from a straight line path) is detected. The WTRU may include timing information (e.g., timestamps) in the report (e.g., to indicate whether the measurements and / or estimations are started / stopped). If the WTRU performs prediction / extrapolation and / or smoothing / interpolation, the WTRU may send timing information (e.g., timestamps) related to the start time, duration, and / or stop time associated with the prediction / smoothing. If the WTRU performs extrapolation / interpolation of its location, the WTRU may send information about the uncertainty of the prediction / smoothing, confidence values, and / or weight values ​​associated with different instances of the extrapolated / interpolated location values.

[0141] The assistance data received by the WTRU may be common across different positioning areas (e.g., including multiple cells / TRPs / gNBs) or may be specific to one or more cells / TRPs / gNBs. If the WTRU receives cell / TRP-specific assistance data (e.g., associated with an ID of the cell / TRP), the WTRU may use the associated assistance data when under coverage of the cell / TRP.

[0142] The WTRU may receive instructions and / or information to the network (e.g., gNB, LMF) (e.g., possibly based on one or more of the triggering events / conditions mentioned above). The instructions and / or information received by the WTRU may include one or more of 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 to initiate SRSp transmission or PRS measurement, or a confirmation / rejection indication of a request (e.g., any request) sent by the WTRU. The WTRU may receive the indication in an RRC_CONNECTED state, an RRC_INACTIVE state, or an RRC_IDLE state. In an embodiment, if the WTRU is INACTIVE, the WTRU may receive the indication in a DL-SDT message (e.g., via an activated SDT configuration, DL-SDT RACH response, SPS-SDT, RRCRelease, etc.). In an example, when the WTRU is IDLE, the WTRU may receive the indication in an RRC message (e.g., RRCSetup, RRCReconfiguration, etc.) or a RACH response message. The WTRU may receive the indication in an updated SIB, which may be accessed by the WTRU after a certain configured duration (e.g., expiration of a timer) when sending an indication to the network.

[0143] An example of a WTRU switching between different positioning modes based on switching criteria is provided herein. The WTRU may switch between the measurement mode and the estimation mode based on detection of one or more conditions and / or trigger 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 as assistance information from the network (e.g., in posSIB, LPP message, RRC signaling, MAC CE). The WTRU may send a request message (e.g., an on-demand request) and / or an activation indication to request activation of the pre-configured switching criteria (e.g., in case of dynamic reception).

[0144] The switching criteria for switching between the measurement mode and the estimation mode may be applied by the WTRU upon detection of one or more of the following triggering events / conditions: measurement accuracy / completeness, instructions from the network / application / higher layers, expiration of PRS / SRSp configuration limits and associated validity conditions, error during estimation / measurement, change in power saving state, change in orbit and / or mobility state, or periodicity (e.g., timer detection).

[0145] If the WTRU detects measurement accuracy / completeness, the WTRU may switch modes if the determined positioning accuracy / completeness value is greater than or less than one or more accuracy / completeness thresholds (e.g., possibly received from the network). The WTRU may switch to the measurement mode when the accuracy associated with the sensor measurements is less than a threshold.

[0146] If the WTRU detects an indication from the network / application / higher layers, the WTRU may switch between modes if it receives an explicit or implicit indication to switch to a different currently applied positioning mode. The explicit indication received by the WTRU may include an identifier associated with the positioning mode (e.g., DL-PRS ID, UL-SRSp ID, estimated 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 SR / BSR for data transmission, etc. If a wake-up signal is received, the WTRU may transition from the estimated mode to the measurement mode to perform DL-PRS measurements or UL-SRSp transmission.

[0147] If the WTRU detects expiration of PRS / SRSp configuration restrictions and associated validity conditions, the WTRU may switch modes if 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. If the WTRU detects that the number of TRPs receiving a PRS with an RSRP above an RSRP threshold falls below a threshold, the WTRU may switch to estimation mode. If a validity condition associated with the PRS / SRSp configuration expires (e.g., TA timer expires, RSRP change of spatially related RS is above / below a threshold, WTRU leaves the validity area, timer expires), the WTRU may switch to estimation mode.

[0148] If the WTRU detects an error during estimation and / or measurement, the WTRU may switch modes if an estimate of the WTRU's location based on sensor or DL-PRS measurements is greater than or less than one or more error thresholds. The WTRU may switch to estimation mode if it receives an explicit or implicit indication from the network that the error due to UL-SRSp transmission is below a threshold. In an embodiment, the WTRU may switch to estimation mode if an RSRP measurement of an RS (e.g., in spatial relationship with SRSp (e.g., DL-PRS, SSB)) is below a threshold.

[0149] If the WTRU detects a change in power saving state, the WTRU may switch modes when transitioning between the RRC_CONNECTED state, the RRC_INACTIVE state, the RRC_IDLE state, and / or any other power saving state.

[0150] If the WTRU detects a change in orbit and / or mobility state, the WTRU may switch modes if (e.g., either) the WTRU's mobility state (e.g., stationary, speed level within a different speed range with different upper and lower limits) changes. The WTRU may switch modes if the WTRU's orbit changes (e.g., the WTRU's location deviates by a certain threshold from an expected location within an expected orbit).

[0151] If the WTRU detects periodicity (e.g., detects a timer), the WTRU may periodically switch modes based on the configured / determined periodicity. The WTRU may use high / low switching periodicity based on changes in the WTRU's mobility state (e.g., when the WTRU's velocity increases above a threshold, the WTRU uses high switching periodicity, and when the velocity remains low or stable, the WTRU uses low periodicity). The WTRU may switch between modes when a timer (e.g., having a configured duration) is set and / or expires.

[0152] When switching / changing from using a first set including one or more PRS / SRSp configurations to a second set of one or more PRS / SRSp configurations, a triggering event / condition (e.g., similar triggering events / conditions described above) may apply. Such switching / changing between PRS / SRSp configurations may occur when operating in a measurement mode and / or an estimation mode.

[0153] The WTRU may be pre-configured with one or more positioning QoS requirements (e.g., accuracy, latency, low power operation, completeness), and different positioning QoS may be associated with different positioning modes (e.g., measurement / estimation modes), 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, possibly based on a priority associated with the positioning QoS. The WTRU may (e.g., may) use different reporting configurations when switching between different positioning modes.

[0154] If the WTRU detects one or more conditions and / or events described in the switching criteria, it may operate partially in measurement mode and partially in estimation mode. If the WTRU detects the availability of a limited PRS configuration (e.g., limited number of TRPs with high RSRP, limited bandwidth), the WTRU may supplement / augment the limited measurements (e.g., using sensor measurements) by operating (e.g., simultaneously) in estimation mode. When the WTRU determines limited PRS measurements, it may increase the time window / interval for operating in estimation mode, and the PRS measurements may be made over a reduced time window / interval.

[0155] The WTRU may be configured with an overall time window indicating a maximum / minimum time interval for performing measurements or estimations. The WTRU may determine a switching time instance and / or associated time interval for operating in the measurement mode and / or estimation mode within the configured overall 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, quality of the measurement (e.g., high / low RSRP, number of multipaths), presence of errors (e.g., timing / phase / sensor errors), or amount of achievable power savings.

[0156] In a WTRU-based mode and / or a WTRU-assisted mode, the WTRU may send an indication to the network (e.g., in an LPP message, RRC signaling, MAC CE, UCI) when switching between the measurement mode and / or the estimation mode, possibly with estimated / determined location information and / or measurement and timing information (e.g., timestamps) when switching. The WTRU may (e.g., may send) the cause of the switch (e.g., cause ID, event ID) in the indication.

[0157] An example of a WTRU that performs LPHAP based on orbit information is provided herein. The WTRU may determine location information when operating in a combination of measurement and estimation modes while ensuring that positioning QoS (e.g., accuracy) requirements are met based on the orbit information. The WTRU may use the orbit information to determine whether the WTRU's location information determined via measurement and / or estimation is within an expected orbit. The WTRU may (e.g., may use) the orbit information to perform corrections to the estimated WTRU's location (e.g., when no measurements are performed).

[0158] The WTRU may receive orbit information or a subset of information (e.g., associated with the WTRU and / or another device / WTRU) that may be attached to or proximate to the WTRU from a network / application (e.g., an LCS client) in an LCS message, an LPP message, or AS layer signaling (e.g., RRC, MAC CE, DCI, etc.). The orbit information may include a set of expected locations (e.g., coordinates) and / or expected time instances (e.g., expected location times) that indicate where / when the WTRU may be located. The orbit information may indicate (e.g., may indicate) where / when the WTRU may operate in a measurement mode and / or an estimation mode. The trajectory information may include (e.g., may include) different IDs, accuracy, and / or error parameters that may be associated with different locations and / or time instances indicated in the trajectory.

[0159] The WTRU may receive trajectory information from the network (e.g., gNB, LMF). If the WTRU receives a trajectory request from the network, the WTRU may send the trajectory information to the network. The trajectory information may include at least one of a motion trajectory (e.g., straight line, curve), acceleration, velocity, a motion direction (e.g., north, west, east, south, angle), or parameters required to describe the WTRU's motion (e.g., dynamic model parameters such as velocity, acceleration, covariance matrix of noise in the model, parameters in the observation model, etc.).

[0160] If the WTRU receives trajectory information from the network or is pre-configured with trajectory information, the WTRU may determine to use the information to perform prediction or smoothing of location information (e.g., correction of past location estimates) for WTRU-based positioning. When the WTRU sends location information, the WTRU may (e.g., may indicate) to the network which model (e.g., an identifier associated with the model) the WTRU used to perform the prediction or smoothing (e.g., whether a straight trajectory was used to predict future location information). The WTRU may (e.g., may indicate) in the report a prediction or smoothing interval (e.g., prediction of location N symbols / slots / frames / milliseconds ahead from the time the location information is reported, smoothed / interpolated location information N symbols / slots / frames / milliseconds ahead from the time the location information is reported).

[0161] The WTRU may include information associated with the predicted or smoothed location at multiple time instances. The WTRU may include future or past timestamps of the information associated with the predicted or smoothed location at one or more of the multiple time instances. The WTRU may include (e.g., may include) model information associated with the predicted or smoothed location at each of the multiple time instances. The WTRU may include predicted WTRU location information at T, 2T, and 3T ms from a timestamp that the WTRU includes in the measurement report. The WTRU may include associated predicted location information in the report (e.g., T, 2T, and 3T ms in the report).

[0162] 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, signaling overhead may be saved.

[0163] An example of an application by the WTRU for LPHAP based on the orbit information may be as follows: The WTRU may receive orbit information (e.g., expected location and / or time instances t0, t1, ... ti) from the network. At time instance t0, the WTRU, when operating in measurement mode, may perform measurements of DL-PRS for a configured duration and determine its actual location. The WTRU may determine a difference / error between its determined actual location and the expected location at t0 indicated in the orbit information. The WTRU may apply the error to correct the actual location for calibration purposes. The WTRU may switch to operate in estimation mode. At time instance t1, the WTRU may estimate its location when in estimation mode (e.g., applying sensor measurements) based on a previously determined actual location (e.g., at t0) and tracking of sensor measurements (e.g., speed, direction, number of instances where direction was changed, time elapsed for each instance since a change in speed and direction was detected). If the WTRU detects an event and / or condition for changing to the measurement mode (e.g., a change in sensing accuracy, timer expiration, periodicity), the WTRU may switch to the measurement mode and perform measurements of the DL-PRS (e.g., possibly using the PRS configuration associated with the closest location and / or time instance indicated in the trajectory (e.g., t1)). If the WTRU detects an event and / or condition for changing to the measurement mode (e.g., a change in sensing accuracy, timer expiration, periodicity), the WTRU may determine its updated actual location based on the measurements and may determine the difference between the updated actual location and the estimated location. If the difference between the actual location and the estimated location is less than a threshold, the WTRU may send an indication to the network indicating that its location is within the expected trajectory. If the difference between the actual location and the estimated location is greater than a threshold, the WTRU may send an indication to the network indicating an error (e.g., a difference in location information) and / or a request for an updated trajectory.If no event to change to the measurement mode is detected by the WTRU, the WTRU may continue to operate in the estimation mode until the next time instance (eg, t2).

[0164] An example of a WTRU performing an LPHAP when triggered by a paging message is provided herein. The WTRU may initiate the LPHAP by triggering operation in measurement mode (e.g., performing PRS measurements or SRSp transmissions) and / or estimation mode (e.g., sensor measurements, predictions) based on receiving a paging message. Paging-based triggering for the LPHAP may be intended to minimize or eliminate signaling associated with operation in the RRC_CONNECTED state and establishing and / or maintaining connectivity with the serving cell / gNB. Such an approach may enable the WTRU to perform a positioning procedure for an extended duration, for example, when operating in a power saving mode (e.g., in the INACTIVE / IDLE state). The paging message may be a paging message used to page the WTRU when there is data to be sent in the DL, or a paging message for positioning purposes (e.g., with a different ID).

[0165] The WTRU may receive configuration information (e.g., in the assistance data) associated with one or more positioning areas, each of which may include one or more cells / TRPs / gNBs. A positioning area may be associated with one or more identifiers and priority values. A positioning area may be associated with / overlap with one or more tracking areas (TAs) and / or RAN paging / notification areas (RNAs). For a DL-based approach, a TRP / gNB in ​​a positioning area may be associated with at least one PRS configuration from which the WTRU may receive DL-PRS for measurements. Similarly, for a UL-based approach, a TRP / gNB in ​​a positioning area may be associated with at least one SRSp configuration, which may be configured by the network to perform measurements of SRSps transmitted by the WTRU. Paging messages received by the WTRU may be received from one or more TRP / gNBs associated with the positioning area. The paging message information / identifier may be associated with a positioning area (e.g., may be, include, or be associated with an area ID) in which the WTRU may perform DL-PRS measurements and / or (e.g., in this case) UL-SRSp transmissions.

[0166] The WTRU may (e.g., may receive) one or more DRX configurations associated with the positioning area / TA / RNA, including parameters associated with DRX cycle duration, DRX on duration, DRX inactivity timer, etc. A WTRU that is in low power operation (e.g., INACTIVE / IDLE state / operation / state) may wake up according to an active DRX configuration to receive DL paging messages during the DRX ON duration.

[0167] The paging message received by the WTRU to trigger the 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 an identifier / preamble to use when sending the measurement report and / or transmitting the SRSp (e.g., the paging message may include configuration information (ID) for the WTRU to apply when generating the preamble / WTRU ID, and the WTRU may scramble the generated preamble / WTRU ID within the SRSp resources when transmitting the SRSp). The paging message may include an identifier associated with the PRS / SRSp configuration and / or parameters to apply (e.g., the WTRU may be pre-configured with one or more resources for PRS / SRSp, and the WTRU may select the PRS / SRSp resources based on the associated ID received in the paging message). The paging message may include information about PRS / SRSp / RACH resources / configurations to use when performing measurements and / or SRS transmissions. The paging message may include information about the positioning mode to apply (e.g., measurement mode and / or estimation mode). The paging message may include information about the trajectory and / or trajectory subset (e.g., ID) to apply / follow. The paging message may include information about timing (e.g., offset, duration, periodicity) of when to start / stop PRS measurements, SRSp transmissions, and / or sensor measurements / tracking to begin. The paging message may include information about changes in pre-configured PRS / SRSp configurations, changes in positioning area, and / or changes in scheduled location time.

[0168] If a paging message is received during a paging occasion, the WTRU may enter into a measurement mode (e.g., performing PRS measurements, transmitting SRSp) and / or an estimation mode (sensor measurements, tracking) based on the information contained in the paging message.

[0169] An embodiment of a WTRU sending information about LPHAP operation to the network is provided herein. The WTRU may send positioning information / indications / reports (e.g., location measurements / estimates) related to the LPHAP to the network in some cases. In an embodiment, the WTRU may send positioning information for the LPHAP based on a reporting configuration received in the assistance data. In an embodiment, the WTRU may send positioning information / reports when it detects a triggering event / condition as described above (e.g., receiving a request from the network, periodic reporting, switching from one to another, detecting an error, etc.). In the context of a UL-based LPHAP, the WTRU may send an indication due to one or more of requesting activation / deactivation of an SRSp configuration and / or a pre-configured SRSp configuration, switching between different SRSp configurations, or reporting positioning information determined via an estimation mode.

[0170] Positioning information / reports related to the LPHAP may be sent by the WTRU (e.g., periodically or aperiodically) based on an event trigger in at least one of an LPP message or an AS layer message (e.g., RRC signaling, MAC CE, UCI, PUSCH data, etc.). The positioning information sent by the WTRU for the LPHAP may include one or more of location information, prediction / smoothing information, error information, achievable positioning QoS, or WTRU mobility / movement information.

[0171] In the case of location information, the WTRU may send its determined / estimated location (e.g., coordinates, location relative to a reference location / landmark) and / or measurements used to determine / estimate its location. Such information may be sent along with the associated positioning mode applied (e.g., measurement mode and / or estimation mode) and timing information (e.g., timestamp). The WTRU may also send information about sensor measurements made to estimate its location and / or measurements made on RRM signals (e.g., CSI-RS, SSB) (e.g., possibly in addition to information about measurements made in DL-PRS). Such information may be used to improve the accuracy of the WTRU's location.

[0172] For prediction / smoothed information, the WTRU may send predicted / extrapolated location information (e.g., for future time instances) and / or smoothed / interpolated location information (e.g., for previous time instances). The WTRU may send timing information (e.g., timestamps) associated with the prediction / smoothing during the duration / window for which the prediction / smoothing is applicable and / or performed by the WTRU and / or during the instance related to when the prediction / smoothing is applicable and / or performed by the WTRU. The WTRU may (e.g., may) indicate a confidence level and / or uncertainty associated with the predicted / smoothed location information.

[0173] With regard to error information, the WTRU may (e.g., may) 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., difference between expected and estimated location).

[0174] In the case of achievable positioning QoS, the WTRU may send information about the achievable positioning QoS (e.g., accuracy, completeness, latency, power savings), possibly with respect to requirements and / or KPIs received from the network / application.

[0175] For WTRU mobility / movement information, the WTRU may send information about its mobility state (e.g., stationary, slow / fast mobile), other mobility / movement attributes (e.g., WTRU speed, direction, distance traveled in a direct / straight line path), and / or mobility path (e.g., a list of one or more cell / TRPs IDs that the WTRU has traversed over a certain duration).

[0176] When operating in low power operation (e.g., INACTIVE / IDLE mode / state / operation), the WTRU may use a small data transmission (SDT) or early data transmission (EDT) configuration to send positioning information / reports. The SDT / EDT configuration received by the WTRU from the network (e.g., serving gNB) may include information about validity conditions (e.g., TA timers) for maintaining SDT / EDT, message payload (e.g., maximum) size, periodicity, and / or resource grants (e.g., SDT configured grants), etc.

[0177] To minimize the amount of reporting and transmission of positioning information during LPHAP operation, the WTRU may send a difference (e.g., delta) in the positioning information relative to information sent in a previous reporting instance. Such differential reports may (e.g., may be) used by the WTRU when reporting prediction / smoothing information of the WTRU's location.

[0178] Different types of positioning information (e.g., location information determined via measurements / estimations, error information, etc.) may be associated with different priority values, which may possibly be received by the WTRU as assistance data from the network. The WTRU may apply different reporting periodicities or urgency levels for sending positioning information based on the priority associated with the information type to be reported (e.g., in this case). Positioning information that may include a change value greater than a threshold with respect to previously reported information may be sent with a higher periodicity or may be triggered with a higher urgency level (e.g., using an SR / BSR configuration associated with high priority / URLLC traffic). The WTRU may send information related to errors and / or changes regarding the expected orbit with a higher periodicity and / or a higher urgency level.

[0179] If the WTRU sends positioning information with high priority (e.g., greater than a threshold), it may indicate or send (e.g., may send) a request message to the gNB to request that the WTRU transition from low power operation (e.g., INACTIVE / IDLE state / mode / operation) to a CONNECTED state operation. If it detects no estimation / prediction error or a small amount of estimation / prediction error (e.g., less than a threshold), the WTRU may reduce the reporting periodicity by sending the saved / stored combined positioning information from a previous time instance.

[0180] The WTRU may be configured with a periodic PRS resource, and the periodic PRS / SRSp may be associated with a periodicity of the DRX cycle.

[0181] The WTRU may be configured with one or more DL PRS configurations / resources and / or UL SRSp resources that 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 states / modes / operation).

[0182] 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 a PRS and / or transmit an SRSp every 5th DRX cycle. For example, if N=1, the WTRU may receive a PRS and / or transmit an SRSp in each 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 DRX cycles not associated with PRS reception and / or SRSp transmission. Such a configuration may (e.g., further) allow the WTRU to perform positioning measurements and / or transmission less frequently compared to reception / transmission of other signals.

[0183] The periodicity of the DRX cycle may correspond to K times the periodicity of the DL-PRS reception and / or UL SRSp transmission. If the periodicity of the DRX cycle corresponds to 1, the DRX cycle may use a decimal value (e.g., 1 / N) for the periodicity of the DL-PRS reception and / or UL SRSp transmission. If the periodicity of the DRX cycle corresponds to K times the periodicity of the DL-PRS reception and / or UL SRSp transmission, the WTRU may perform up to K PRS receptions and / or K SRSp transmissions in a DRX cycle.

[0184] The periodicity of DL-PRS reception and / or UL SRSp transmission may be configured independent of the periodicity associated with the DRX cycle. If the WTRU is configured with a PRS and / or SRSp in one or more timeslots / occasions that overlap with the active / on duration of the configured DRX cycle (e.g., in this case), the WTRU may perform PRS measurements and / or SRSp transmissions in the active duration according to the configuration. If the WTRU is configured with a PRS and / or SRSp that is outside the active / on duration of the configured DRX cycle, the WTRU may wake up in one or more timeslots / occasions for one or more of monitoring signaling associated with positioning (e.g., any signaling), receiving a PRS, or transmitting an SRSp.

[0185] The WTRU may be preconfigured with one or more periodicity values ​​for the PRS and / or SRSp. The WTRU may be (e.g., may be) preconfigured with associated triggering conditions / events. The associated triggering conditions / events may be monitored by the WTRU to determine an appropriate periodicity value to apply (e.g., when a triggering condition / event occurs, the respective periodicity value may be applied). In an embodiment, the WTRU may be configured with first and second periodicity values ​​for the PRS and / or association information indicating an association with a DRX configuration configured in the WTRU. The WTRU may use the first periodicity value (e.g., high periodicity with multiple PRS in a single DRX active duration) for PRS measurements when (e.g., in this case) a first DRX configuration (e.g., long DRX cycle) is applied. The WTRU may use the second periodicity value (e.g., low periodicity with PRS occurring after multiple DRX cycles) for PRS measurements when a second DRX configuration is applied (e.g., short DRX cycle).

[0186] The WTRU may receive periodicity configuration values ​​for PRS and / or SRSp from the network (e.g., LMF and / or gNB) when in CONNECTED state and / or when transitioning to low power operation (e.g., INACTIVE / IDLE state / mode / operation) (e.g., via an RRC release message). In an embodiment, the WTRU may receive periodicity configuration values ​​for PRS / SRSp via one or more of MT-SDT, paging message, RRC message, MAC CE, or DCI when in low power operation (e.g., INACTIVE / IDLE state / mode / operation). Such periodicity configuration values ​​may be received by the WTRU from the network based on information and / or indication of DRX configuration (e.g., periodicity, cycle duration, on / active duration) and / or changes to DRX parameters provided by the WTRU to the network.

[0187] An embodiment for supporting DL-based LPHAP is provided herein. If the WTRU supports LPHAP, it may use DL-based positioning to mitigate positioning errors. A WTRU operating in a measurement mode and / or estimation mode may (e.g., may provide) low positioning errors and high power savings when performing limited DL measurements (e.g., DL-PRS, CSI-RS, SSB) or no DL measurements (e.g., DL-PRS, CSI-RS, SSB). Positioning errors may be caused by errors or inaccuracies in determining the initial location and / or reference location of the WTRU (e.g., at a reference time instance, as the case may be). This may be due to errors as a result of one or more of insufficient or inaccurate DL-based measurements (e.g., low bandwidth, few TRPs), errors in hardware / devices (e.g., sensors applied), or errors in the wireless environment (e.g., many multipaths, unavailability of LOS paths). As a result of positioning errors at the initial / reference location, when the WTRU estimates its location (e.g., when in estimation mode) based on previous estimates and / or measurements (e.g., each time instance), the error value may vary, increase, and drift to subsequent time instances at which an estimation may be made.

[0188] To mitigate positioning errors, the WTRU may receive assistance data from the network / application including at least one of: one or more DL-PRS configurations (e.g., associated with different accuracy levels, amounts of resources, priorities, etc.), one or more trajectories and / or components / subsets of trajectories (e.g., having corresponding IDs) that the WTRU is expected to follow, correction information for correcting measurements made when determining a reference location of the WTRU, or one or more thresholds associated with the positioning errors.

[0189] The WTRU may perform an initial measurement on DL-PRS to determine a first reference location of the WTRU at a reference time instance t0. The WTRU may provide (e.g., ensure) high accuracy when determining the reference location by using at least one DL-PRS configuration associated with high accuracy (e.g., high bandwidth, high periodicity, multiple TRPs) and / or applying correction information. The WTRU may receive (e.g., in posSIB or dedicated LPP signaling) one or more DL-PRS configurations that may be intended to be used by the WTRU based on one or more of the type of location (e.g., reference location or intermediate location), time instance / duration, mobility state (e.g., stationary, low speed or mobile below a speed threshold, high speed or mobile above a speed threshold), or expected accuracy level of the prediction at which measurements may be made to determine the WTRU's location. To determine the reference location, the WTRU may select and / or use the first DL-PRS configuration or parameters associated with achieving high accuracy. To determine an intermediate location (e.g., any intermediate location), the WTRU may use parameters associated with the second DL-PRS configuration or a medium level of accuracy. Selection of the DL-PRS configuration and / or parameters (e.g., similar selection) may be performed by the WTRU based on a mobility state. When selecting a DL-PRS configuration, the WTRU may indicate the selected configuration and / or parameters associated with the configuration (e.g., an ID of the configuration or parameters) to the network (e.g., in an on-demand request message or an activation request message).

[0190] The WTRU may estimate and / or predict its expected location at future time instance t1 based on the determined reference location and the expected trajectory. The WTRU may, for example, apply a prediction model to predict the expected location 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., as the case may be, indicated in the expected trajectory or determined by the WTRU based on tracking). The WTRU may, in some cases, operate in an estimation mode between t0 and t1 to conserve power by not performing or performing limited PRS measurements. The WTRU may, after reaching the expected location at t1, select an appropriate DL-PRS configuration (e.g., associated with an area in which the WTRU may be located and / or a mobility state of the WTRU) and / or perform PRS measurements to determine the actual location. The WTRU may (e.g., may) use the measurement and / or tracking information determined during the estimation mode to determine the actual location at t1. In an embodiment, the determined actual location may correspond to a second reference location.

[0191] The WTRU may (e.g., may then determine) a difference between the estimated / predicted location at t1 and the actual location to identify an error in the prediction model, trajectory, and / or measurements. If the determined error is equal to or less than an error threshold, the WTRU may apply the determined error as feedback information to correct the prediction model, trajectory, and / or measurements. The WTRU may send an indication to the network with status information about the WTRU's location and / or the determined error. The WTRU may (e.g., may apply) the error to correct previous estimates of the WTRU's location at intermediate time instances, e.g., from t0 to t1. If the determined error is greater than an error threshold, the WTRU may send an indication to the network indicating information about the determined error, the WTRU's location, a request for an updated DL-PRS configuration, updated trajectory information, etc. The WTRU may (e.g., may also) reset (e.g., to t0) tracking of the reference location and / or reference time instance (e.g., possibly to use a DL-PRS configuration with a different periodicity), for example, based on the determined error level. The WTRU may use a first DL-PRS configuration (e.g., having a high periodicity) at a first reference location. The WTRU may (e.g., may then use) a second DL-PRS configuration (e.g., having a low periodicity) at a second reference location if an error corresponding to a difference between an estimated / predicted location and an actual location (e.g., at or near a second reference location) is below a threshold. Otherwise, if the error is greater than a threshold, the WTRU may use the first DL-PRS configuration (e.g., a high periodicity configuration) at the second reference location.

[0192] Examples of WTRUs implementing LPHAP based on location-dependent configurations and / or resources are provided herein. The WTRU may implement LPHAP using DL-based configurations and / or resources, which may depend on a positioning area or zone that overlaps and / or is adjacent to a 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 for sending 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., when operating in low power operation (e.g., INACTIVE / IDLE state / mode / operation)). Different TRPs / gNBs may be common across different positioning areas, or may not overlap, and / or may be specific to a particular positioning area.

[0193] The WTRU may receive pre-configured information about associations between one or more of positioning areas (e.g., area IDs), cells / TRPs / gNBs (e.g., TRP IDs, PCIs), DL-PRS configurations / resources (e.g., configuration / parameter IDs), or UL resources for sending reports / indications (e.g., configured grants). The WTRU may (e.g., may receive) information about associations between area / time validity conditions and / or validity conditions, positioning areas, and configurations / resources. Such association information may be received by the WTRU via posSIB (e.g., via broadcast from one or more TRPs / gNBs in the positioning area) (e.g., when the WTRU is in RRC CONNECTED state), via LPP messages, or via AS layer messages (e.g., in RRC, MAC CE, DCI). The association information may be stored in the WTRU or may be received (e.g., via SDT) when in RRC INACTIVE / IDLE state. A WTRU, which may be in proximity to one or more TRP / gNBs in its positioning area, may select at least one DL-PRS configuration. The WTRU may use the selected configuration to perform measurements on the PRS. Such procedures for positioning may be supported by the WTRU when in RRC INACTIVE / IDLE state (e.g., possibly without the need to establish a connection (e.g., any connection or signaling) with the network).

[0194] The WTRU may predict a DL-PRS configuration to apply at a future location and / or time instance based on previous and / or current positioning areas, association information between DL-PRS configurations and positioning areas, and the expected WTRU trajectory. The WTRU may determine a DL-PRS configuration to apply when entering a positioning area (e.g., entering a new positioning area upon detecting a new cell / TRP / gNB ID) 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 needing to receive additional SIBs or establish connectivity with the network.

[0195] Different positioning areas may (e.g., may be) associated with different DL-PRS configurations / parameters, which may be associated with different positioning QoS requirements (accuracy, latency, completeness, etc.) and / or radio conditions (e.g., RSRP measurements, LOS / NLOS, multipath, etc.). In an embodiment, given a set of different DL-PRS configurations associated with positioning areas in which a WTRU may be located, the WTRU may select a DL-PRS configuration or parameters from the set based on the positioning QoS expected to be achieved. The WTRU may select a DL-PRS configuration or parameters from the set based on whether RSRP measurements and / or multipath detections made for the DL-PRS or RS (e.g., which may be in a spatial relationship with the DL-PRS) are less / greater than one or more thresholds.

[0196] A different PRS configuration associated with a positioning area, received by the WTRU (e.g., in the association / assistance information), may include at least two subsets of resources and / or parameters (e.g., periodicity, duration). The first and second subsets may be in the same resource pool associated with the PRS configuration and / or from different resource pools (e.g., the first subset may be RRM resources and the second subset may be DL-PRS), which may have a spatial / QCL relationship with each other. The first subset may be used by the WTRU to perform restricted measurements during LPHAP operation (e.g., measurement mode or estimation mode) and / or to determine the suitability of the associated DL-PRS to meet positioning QoS requirements. The resources and / or parameters in the first and second subsets may be overlapping or non-overlapping. For example, the first subset may include restricted resources, while the second subset may include the 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 achievable when using the corresponding DL-PRS configuration.

[0197] The first subset may have PRS resources that may be transmitted with a low periodicity value (e.g., 5 transmissions per subframe), while the second subset may have PRS resources that may be transmitted with a higher periodicity value (e.g., 20 transmissions per subframe). Before selecting a DL-PRS configuration, the WTRU may perform measurements (e.g., in this case) on the first subset to determine the quality of the radio conditions (e.g., RSRP) and / or the WTRU's positioning information. The WTRU may determine (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 / less than one or more thresholds) and / or whether the determined accuracy of the WTRU positioning information is satisfactory (e.g., an error on the information determined via the estimation mode is less / greater than one or more thresholds).

[0198] 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, resource) from the SIB or pre-configuration based on an association between the PCI and the first subset (e.g., possibly indicated in the SIB or other DL messages / 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. If the determined RSRP of 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 to achieve higher positioning accuracy at a current or future location and / or time (e.g., using prediction / extrapolation). The measurements in the second subset may be to compensate for lower accuracy achieved at a previous location and / or time instance (e.g., using smoothing / interpolation).

[0199] If the determined RSRP of measurements associated with one or more cells / TRPs is below a threshold, the WTRU may supplement / compensate for the insufficient measurements using estimations made by operating in an estimation mode (e.g., sensor measurements, trajectory tracking, predictions). The WTRU may send an indication / report to the network based on one or more of a selection of the first and / or second subset of resources and / or parameters to be applied for the measurements, the operating mode (measurement / estimation mode) applied, timing information (e.g., timestamps) indicating when the first and / or second subsets are applied, or an error / accuracy determined when using the first / second subsets.

[0200] An example of a WTRU using a DL-based positioning configuration based on TRS reception is provided herein. The WTRU may determine a DL-PRS configuration to apply based on reception and / or measurement of a tracking reference signal (TRS) during LPHAP (e.g., operation in measurement and / or estimation modes). The TRS used for time-frequency synchronization may be realized using a CSI-RS with a sparse configuration including a sparse set of resources / symbols. When operating in a power saving mode (e.g., with off duration during INACTIVE / IDLE state), the WTRU may wake up periodically (e.g., to maintain synchronization with the network, in some cases) to measure the presence of DL signals (e.g., primary synchronization signal (PSS), secondary synchronization signal (SSS), SSB, paging signal, wake-up signal / indication). Such a procedure may be performed before the WTRU may be able to receive DL-PRS for positioning measurements. However, waking up to detect / decode DL signals (eg, periodic wake-ups) may result in (eg, additional) power consumption and higher latency.

[0201] A WTRU in a power save mode (e.g., low power operation or INACTIVE state / mode / operation) may receive a TRS to perform time-frequency synchronization with the network before receiving a DL-PRS for measurement. The WTRU may be configured with DRX in a power save mode. The WTRU may receive a TRS before an on-duration or a paging occasion (e.g., with a configured offset duration 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 latency (e.g., additional latency) associated with transmitting, receiving, and / or processing other signaling and measurements.

[0202] 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 whether (e.g., if) synchronization with the base station / gNB / TRP can be achieved using the TRS. To use a PRS configuration with low bandwidth, the WTRU may perform initial synchronization with the TRS, while to use a PRS configuration with wide bandwidth (e.g., for high accuracy), the WTRU may perform synchronization with the SSB.

[0203] 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 selecting a PRS configuration based on TRS, the WTRU's mobility state, positioning areas (e.g., cells / TRPs / gNBs), or reference locations and / or time instances. Such association information may be received by the WTRU via SIBs, 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 indicate (e.g., may indicate) that the WTRU may expect to receive the PRS a certain number of slots / symbols after receiving the TRS. For different associations between TRS and PRS configurations, the number of slots / symbols after which the WTRU may expect to receive the PRS after receiving the TRS may vary.

[0204] A positioning area may be associated with one or more TRS configurations per cell / TRP / gNB. Different TRS configurations may be (e.g., may be) associated with one or more PRS configurations having different bandwidths / resources. A WTRU in a positioning area may determine a PRS configuration to apply for positioning based on measurements made on the associated TRS.

[0205] Examples are provided herein in which the WTRU performs WTRU location prediction to compensate for reduced DL measurements. When the WTRU is operating in a power saving mode (e.g., INACTIVE / IDLE state / mode / operation), it may compensate for the lack of measurement information by sending a report to the network on 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., straight path, left curve, right curve, or parameters describing the WTRU's movement / movement), timing information for prediction / smoothing (e.g., scheduled time occasions (e.g., T0, T1, T2, ...), prediction intervals (D1) for determining future WTRU locations, and smoothing intervals (D2) for determining intermediate WTRU locations), one or more thresholds associated with prediction errors (e.g., difference between actual location and predicted / estimated location), or reporting configurations that may include time occasions at which the WTRU is expected to send positioning information to the network.

[0206] The WTRU may send information about an initial trajectory (e.g., moving in a straight line path). The WTRU may receive PRS configurations and / or resources associated with the reported trajectory, which may be applied during the measurement mode and / or the estimation mode. At a first time occasion (e.g., T0), the WTRU may perform PRS measurements using the received PRS configurations and / or resources. The WTRU may perform prediction of the WTRU location at a different prediction interval (D1) until a second time occasion (e.g., T1) based on operation in the estimation mode and / or the trajectory information. At the second time occasion (e.g., T1), the WTRU may perform PRS measurements using the received PRS configuration. The WTRU may determine an actual WTRU location at the second time occasion based on the measurements. The WTRU may determine (e.g., then determine) a prediction error (e.g., a difference between the actual WTRU location at T1 and the estimated WTRU location). If the prediction error is less than the first threshold, the WTRU may determine (e.g., possibly using smoothing / interpolation techniques) location information of the WTRU in intermediate instances and / or locations of a smoothed interval between the first and second time occasions. The WTRU may send an estimated WTRU location in a smoothed interval between the first and second time occasions (e.g., in a subsequent reporting occasion). The WTRU may send an estimated / predicted WTRU location in some cases upon detecting another triggering event (e.g., a change in WTRU orbit or a change in mobility state). If the prediction error is greater than the first threshold and / or less than the second threshold, the WTRU may apply certain adjustments to a prediction / smoothing model applied in the estimation mode and / or may implement corrections to the estimated WTRU location in intermediate instances and / or locations to determine corrected WTRU location information. The WTRU may send (e.g., then send) the corrected estimated WTRU location information to the network. If the prediction error is greater than a second threshold, the WTRU may send actual location information determined at a second time occasion via measurements of the DL-PRS.The WTRU may (e.g., may send) an indication to request updated configuration and / or assistance data for prediction / smoothing and / or timing information (e.g., new timing information) for a PRS configuration (e.g., an updated PRS configuration with higher bandwidth, higher density).

[0207] The WTRU may determine, for example, INACTIVE / IDLE state / mode / operation. The WTRU may determine, for example, what to include in a measurement report and / or how to send the measurement report when performing DL-based positioning when in INACTIVE / IDLE state (e.g., this may potentially minimize the number / amount of transmissions and / or improve power savings for LPHAP in the WTRU). The WTRU may be configured to perform DL-PRS measurements using one or more of the following reporting modes when sending measurement reports to the network when operating in INACTIVE / IDLE state: staggering measurements, skipping or resuming reports, differential reporting, or dropping measurements.

[0208] To stagger measurements, the WTRU may be configured to perform RSRP / RSTD measurements of received PRS over one or more periods / occasions. The WTRU may stagger one or more measurements over M occasions before transmitting the measurement. In an embodiment, the number of occasions M for staggering measurements may be preconfigured in the WTRU. In an embodiment, the number of occasions M for staggering measurements may be determined by the WTRU based on one or more factors including timer expiration or the amount of increase / decrease in the RSRP / RSTD measurement relative to the previous / reference measurement.

[0209] To skip or resume reporting, the WTRU may decide to skip sending one or more measurement reports (e.g., if the WTRU is configured to perform measurements on DL-PRS) (e.g., if the change in the measurement made with respect to the previous / reference measurement is below a threshold (e.g., RSTD / RSRP difference threshold)). The WTRU may resume sending measurement reports if the change in the measurement made with respect to the previous / reference measurement is above a threshold.

[0210] For differential reporting, the WTRU may report a difference or delta relative to a reference location and / or reference time instance (e.g., if the WTRU is configured to report PRS measurements and / or location estimates). The reference location may correspond to the WTRU's location at an earlier time instance, or the location of a landmark / anchor point. The reference time instance may correspond to a start, initialization, or trigger time instance tracked by the WTRU. When implementing differential reporting, the WTRU may report information about the reference point / time (e.g., the ID or location of the reference point) and / or differences regarding the location and / or measurements made / expected at the reference point / time to the network.

[0211] With regard to dropping measurements, the WTRU may drop one or more measurements or estimates if one or more of the following conditions are met: expiration of a configured timer, low reporting priority, detection of a positioning error, degraded positioning accuracy, degraded battery capacity (e.g., below a threshold), or increased Tx power for transmitting the report.

[0212] When sending 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 to indicate one or more of the timing corresponding to when the measurement or estimation was made or the timing corresponding to a switch from one reporting mode to another.

[0213] The WTRU may send positioning information to the network when operating in low power operation (e.g., INACTIVE state / mode / operation). A WTRU in the INACTIVE state may determine whether to send or skip a report of positioning information to the network based on the determined prediction error. In an embodiment, 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 sending a positioning report, and / or a prediction error threshold (e.g., difference between actual location and predicted location). The WTRU may receive mobility attributes of the WTRU (e.g., WTRU speed and / or movement direction) from higher layers. The WTRU may perform a first PRS measurement at a first time occasion (T1) and determine the location of the WTRU at T1. The WTRU may determine a predicted WTRU location at a second time occasion based on the determined first WTRU location and mobility attributes. The WTRU may send a positioning report to the network including the determined WTRU location at T1 and the predicted WTRU location at T2. The WTRU may perform a second PRS measurement at a second time occasion (T2) and determine the WTRU location at T2. The WTRU may determine a prediction error based on the determined WTRU location and the predicted WTRU location at T2. The WTRU may skip sending a positioning report at T2 if the prediction error is less than a threshold. The WTRU may send a positioning report to the network including the determined WTRU location at T2 if the prediction error is greater than a threshold.

[0214] When the WTRU is in low power operation (e.g., operating in an INACTIVE state / mode), it may send an indication to the network to assist in predicting the WTRU's location. A WTRU in an INACTIVE state may determine whether to send an ACK indication or a measurement report to the network based on the determined prediction error. In an embodiment, 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) including one or more PRS configurations, a time occasion (e.g., T1, T2) for sending a positioning report, and / or a prediction error threshold (e.g., a difference between an actual location and a predicted location). The WTRU may receive a first set of 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's location at T1. The WTRU may transmit a positioning report to the network including the determined WTRU's location at T1 and the first set of mobility attributes. The WTRU may receive a predicted WTRU location from the network at T2. The WTRU may receive a second set of mobility attributes of the WTRU (e.g., WTRU speed and / or direction of movement) from higher layers. The WTRU may perform a second PRS measurement at a second time occasion (T2) and determine the WTRU's location at T2. The WTRU may determine a prediction error based on the determined WTRU location and the predicted WTRU location at T2. The WTRU may send an ACK message to the network (e.g., to indicate that the prediction at the network is valid) if the prediction error is less than a threshold. The WTRU may send a positioning report to the network including the determined WTRU location at T2 and the second set of mobility attributes (e.g., any of them) if the prediction error is greater than a threshold.

[0215] An example for supporting UL-based LPHAP is provided herein. The WTRU may transmit UL-SRSp transmission for LPHAP based on the UL configured positioning area. The WTRU may transmit SRSp using one or more SRSp configurations and / or resources (e.g., periodic, aperiodic, semi-persistent) that may be applicable across different UL configured positioning areas while operating in a power saving mode during mobility. The UL configured positioning area may include one or more cells / TRPs / gNBs that may be configured to perform measurements on the SRSp transmitted by the WTRU. Different positioning areas that the WTRU may traverse according to the WTRU trajectory may be associated with different SRSp configurations. The WTRU may use resources from the SRSp configuration for SRSp transmission based on the positioning area / validity area in which the WTRU may be located. The SRSp configuration may be (e.g., may be) associated with a validity time or a scheduled time that indicates a schedule when the WTRU may start / stop using the SRSp configuration for SRSp transmission.

[0216] An SRSp configuration may be associated with a positioning area and a scheduled time, which may be (e.g., may be) associated with the WTRU's orbit. The WTRU may receive a pre-configured SRSp configuration (e.g., in this case) from the network (e.g., the serving gNB). The WTRU may select an SRSp configuration from the pre-configuration based on a positioning area in which the WTRU may be located and / or the associated scheduled time. The WTRU may receive (e.g., may receive) one or more SRSp configurations (e.g., for use during low power operation (e.g., power saving mode or INACTIVE / IDLE state / mode / operation) in different positioning areas and / or that may be associated with achieving different positioning QoS (e.g., achievable accuracy based on measurements made by the TRP / gNB) within the positioning area. A WTRU within a positioning area may select an SRSp configuration based on one or more of an SRSp configuration that may be associated with the positioning area, a sub-area within the positioning area, or an expected positioning accuracy level to be achieved.

[0217] To determine a positioning area / subarea in which the WTRU may be located, the WTRU may (e.g., initially) receive / detect IDs of one or more cells / TRPs / gNBs (e.g., that may be proximate to the WTRU and associated with the positioning area) via SIB / SSB / PBCH. The WTRU may estimate the WTRU's location and determine a corresponding positioning area and associated SRSp configuration to apply based on operation in an estimation mode (e.g., predictions, sensor measurements, tracking orbits, etc.). The WTRU may determine an SRSp configuration to apply if the accuracy / error of the WTRU's location within the positioning area is determined based on the estimation mode operation to be greater / less than one or more thresholds.

[0218] To determine whether an expected positioning QoS level may be achievable by the SRSp transmitted by the WTRU and / or measurements made by the corresponding TRP / gNB, the WTRU may perform measurements on DL signals (e.g., DL-PRS, CSI-RS, SSB, TRS, RS that are in a spatial / QCL relationship with the SRSp). The measurements on the DL signals may determine radio link quality (e.g., RSRP measurements, number of multipaths, LOS / NLOS indications) corresponding to one or more TRP / gNBs associated with a positioning area in which the WTRU may be located. Association / assistance information related to the DL signals 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 in a spatial relationship with the SRSp and / or may be transmitted from a TRP / gNB from which the WTRU intends to transmit the SRSp. The WTRU may select an SRSp configuration based on the radio link quality. The WTRU may select a low-bandwidth SRSp configuration if the RSRP of the corresponding DL signal (e.g., as may be measured by the WTRU) is greater than a threshold. The WTRU may select a high-bandwidth SRSp configuration if the RSRP of the corresponding DL signal (e.g., as may be measured by the WTRU) is less than a threshold. Selection of different SRSp configurations based on the quality of the associated DL signal may enable achieving different and / or consistent levels of positioning accuracy during SRSp transmission.

[0219] The WTRU may determine an SRSp configuration to apply to achieve an expected positioning QoS level based on operation in the estimation mode (e.g., predictions, sensor measurements, tracking orbits, etc.). The WTRU may use a low-bandwidth, low-periodicity SRSp configuration to transmit the SRSp in the UL. The WTRU may determine (e.g., 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's location determined via SRSp measurements in the network. The WTRU may determine (e.g., then determine) a high-bandwidth, high-periodicity SRSp configuration to use to transmit the SRSp and / or achieve 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 with the low-bandwidth, low-periodicity SRSp configuration is greater than or less than one or more thresholds.

[0220] The WTRU may (e.g., may 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 the first speed level to a second speed level). The WTRU may use a first SRSp configuration (e.g., a high periodicity SRSp configuration) when changing from a stationary mobility state to a low speed mobility state to determine (e.g., ensure) that the WTRU's location can be determined with high accuracy when measuring SRSp transmitted by the WTRU in the network. The WTRU may use a second SRSp configuration (e.g., a low periodicity SRSp configuration) when the mobility state remains stable (e.g., within a speed range or within one or more thresholds). The WTRU may use the second SRSp configuration to maintain a positioning accuracy level and / or for power conservation. When changing from a first SRSp configuration to a second SRSp configuration, the WTRU may send an indication to the network (e.g., in an LPP message, RRC, MAC CE, UCI, etc.) to activate measurements of the SRSp transmitted by the WTRU.

[0221] An example of a WTRU that performs UL-based LPHAP based on location-dependent configurations and / or resources is provided herein. The WTRU may determine that SRSp resources are used to perform 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 it is located within the associated positioning area and / or detects at least one TRP / gNB in ​​the positioning area (e.g., reception of PCI / cell ID and / or RSRP of a radio link is above a threshold). A location-dependent SRSp configuration for the LPHAP, including a set of resources and a subset of resources indicated for activation / deactivation of the SRSp configuration, may be received by the WTRU in one or more of an RRC CONNECTED state, an RRC release message (e.g., in a SuspendConfig message), an SDT DL message, a SIB, or a paging message.

[0222] For the RRC_CONNECTED state, the WTRU may receive the SRSp configuration when it sends a request for positioning services (e.g., via an LPP / LCS request or an RRC request) to the serving gNB when in the CONNECTED state and / or when transitioning to low power operation (e.g., INACTIVE / IDLE state). The WTRU may receive information about positioning areas for which the SRSp configuration may be valid. The received SRSp configuration may be stored and used by the WRTU that detects the associated positioning area. For an RRCRelease message (e.g., in a SuspendConfig message), the WTRU may receive the SRSp configuration when releasing the WTRU 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 using a two-step RACH procedure or in Msg 4 when using a four-step RACH procedure). The SIB may include a SIB broadcast message (e.g., posSIB). The paging message may be received by the WTRU (e.g., with a WTRU ID) from one or more TRP / gNBs within its positioning area.

[0223] 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, an RSRP change, or a validity area.

[0224] Regarding 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. A WTRU pre-configured with an SRSp configuration may activate the SRSp configuration to transmit SRSp when the TA timer is configured and / or set (e.g., when under coverage of a cell and / or positioning area). The WTRU may deactivate SRSp transmission when the TA timer expires. The WTRU may retain the SRSp configuration without releasing it for subsequent use, or may release the SRSp configuration when the TA timer expires, possibly based on detection of an explicit or implicit indication received from the network (e.g., via a duration configured for the TA timer).

[0225] For RSRP change, if the RSRP measured for DL ​​signals (e.g., RS) received from one or more TRPs in the positioning area (which may be in a spatial relationship with the SRSp) is less than or greater than one or more thresholds, the SRSp configuration may be activated / deactivated / released by the WTRU. In an embodiment, i) the WTRU may activate the SRSp configuration if the RSRP is less than a first threshold, ii) the WTRU may deactivate the SRSp configuration if the RSRP is greater than the first threshold and less than a second threshold, and iii) the WTRU may release the SRSp configuration if the RSRP is greater than the second threshold.

[0226] With respect to the validity area, the SRSp configuration may be activated / deactivated / released by the WTRU when entering / leaving a positioning area that includes the coverage of one or more cells / TRPs / gNBs. The WTRU may activate the SRSp configuration if it detects a first TRP in the positioning area and deactivate / release the SRSp configuration if it detects a second TRP in the same / different positioning area.

[0227] The SRSp configuration may be received by the WTRU from a serving gNB using any of the approaches discussed herein (e.g., after establishing an RRC connection) or from a non-serving gNB (e.g., without establishing an RRC connection). For a non-serving gNB that may be located within a positioning area in which the WTRU may be located, the WTRU may indicate a request for an SRSp configuration and / or resources by sending a RACH message / preamble associated with the request. A WTRU (e.g., a WTRU that is pre-configured with one or more SRSp configurations) may send a request for SRSp activation / deactivation by sending a RACH message / preamble associated with an activation request (e.g., with a WTRU ID and / or SRSp configuration ID).

[0228] An example of a WTRU using a common SRSp resource based on sensing is provided herein. The location-dependent SRSp configuration and / or resources may not be dedicated to a given WTRU and / or may be common to multiple WTRUs located within a positioning area. This may result in interference if multiple WTRUs (e.g., possibly located in close proximity) transmit SRSp simultaneously using the common SRSp resource. The WTRU may include an identifier (e.g., in this case) associated with the WTRU (e.g., preamble / WTRU ID / RA-RNTI) and / or an SRSp transmission request in a UL message (e.g., RRC message sent on RACH, RACH-SDT) before transmitting SRSp using the common SRSp resource.

[0229] The WTRU may transmit an SRSp using the common SRSp resources if it receives a DL indication (e.g., in a DL SDT) from the network acknowledging / activating the SRSp resources and / or identifiers that may be associated with the WTRU. The WTRU may include and / or scramble the identifiers associated with the WTRU when transmitting the SRSp. The WTRU may initiate sensing and / or listen-before-talk (LBT) procedures to determine if the common SRSp resources are currently being used by other WTRUs in the vicinity. In an embodiment, the WTRU may perform sensing / LBT for a configured duration and / or measure an energy level (e.g., RSRP) over the SRSp resources. The WTRU may use the SRSp resources for a certain duration (e.g., channel occupancy time (COT) associated with the SRSp configuration) if the measured energy level (e.g., average, peak) is below a threshold over the sensing / LBT duration. The WTRU may wait (e.g., may wait otherwise) for a certain duration (e.g., a random number of time slots, over a configured number of slots) before resuming sensing / LBT procedures to access the common SRSp resource.

[0230] The common SRSp resource may be accessed by the WTRU to determine (e.g., guarantee) a certain positioning accuracy achieved (e.g., when the TRP / gNB performs measurements of the SRSp transmitted by the WTRU). Positioning accuracy levels (e.g., in this case) may be associated with different priority values ​​that may be used by the WTRU to access the common SRSp resource. The use of such priority values ​​may result in using SRSp resources with different COTs during SRSp transmission. A WTRU intending to achieve a high accuracy level 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 transmission. A WTRU seeking to achieve an intermediate level of accuracy level 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 transmission. The association between the SRSp resources, the priority values, and / or the COT values ​​may be received by the WTRU as assistance information / dynamic indication from the network (eg, via an LPP message, an RRC message, a SIB, a MAC CE, a DCI, etc.).

[0231] Provided herein is an example of a WTRU changing / switching between SRSp configurations to support UL-based LPHAP based on detection of a triggering event. 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., a change in WTRU mobility state, receipt of a DL indication, etc.).

[0232] Examples include the following: A WTRU may receive configuration information including one or more SRSp configurations including resources in at least 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 occasions (e.g., T0, T1, T2...) for transmitting the SRSp, where each time occasion (T1) may be associated with the same or different SRSp configuration. In an embodiment, 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 / pause duration D. In an embodiment, the Tx update duration may refer to a duration during which the WTRU may not perform SRSp transmission and / or may change from the first SRSp configuration to the second SRSp configuration.

[0233] The WTRU may receive configuration information when in RRC_CONNECTED state (e.g., as pre-configured), RRC_INACTIVE state (e.g., via RRCRelease message in SuspendConfig), or RRC_IDLE state (e.g., via RACH / initial access message during initial access procedure, paging message). Configurations received while in CONNECTED or INACTIVE state may be used and / or activated when operating in INACTIVE and / or IDLE state. The WTRU may transition to INACTIVE or IDLE state (e.g., after receiving configuration information while operating in CONNECTED / INACTIVE state) or may be transitioned to INACTIVE or IDLE state by the network.

[0234] When a first triggering event for initiating an SRSp transmission (e.g., a change in mobility state, receipt of a DL indication) is detected, the WTRU may start a first timer (e.g., for a configured period of time). The first timer may run for a certain duration (e.g., T1 to T0) spanning the next Tx occasion minus the current Tx occasion. When a first triggering event for initiating an SRSp transmission (e.g., a change in mobility state, receipt of a DL indication) is detected, the WTRU may select an SRSp configuration associated with the current SRSp Tx occasion. In an embodiment, the WTRU may select a first SRSp configuration (e.g., high periodicity) when the current SRSp Tx occasion is T0, and the WTRU may select a second SRSp configuration (e.g., low periodicity) when the current SRSp Tx occasion is greater than T0. Upon detecting a first triggering event to begin SRSp transmission (e.g., mobility state change, receiving DL indication), the WTRU may send an indication to the network (e.g., gNB / base station) indicating the start of SRSp transmission when the current Tx occasion is T0. In an embodiment, when the WTRU is in INACTIVE state, the WTRU may send the indication in the SDT using RACH or CG resources associated with the SDT. In an embodiment, when the WTRU is in IDLE state, the WTRU may send the indication in an initial access / RACH message (e.g., RRCRequest, RRCSystemInformationRequest, RRCReconfigurationRequest, or a RACH / RRC message associated with positioning). In an embodiment, the WTRU may send the indication when IDLE on a RACH occasion (e.g., possibly associated with positioning). When sending the indication in INACTIVE / IDLE, the WTRU may include flags / information and / or use resources associated with low power positioning so that the WTRU cannot be transitioned to CONNECTED state. In an embodiment, the WTRU may send an indication to the network when transitioning to the CONNECTED state, possibly for non-positioning or positioning related reasons.

[0235] When a first triggering event to begin SRSp transmission (e.g., mobility state change, receipt of DL indication) is detected, the WTRU may receive an indication from the network (e.g., in LPP, RRC, MAC CE, DCI, etc.) and possibly confirm / activate SRSp transmission using the selected SRSp configuration. In an embodiment, if the WTRU is in INACTIVE (e.g., INACTIVE state / mode / operation), the WTRU may receive the indication in a DL-SDT message (e.g., via an activated SDT configuration, DL-SDT RACH response, SPS-SDT, RRCRelease). In an embodiment, if the WTRU is in IDLE (e.g., IDLE state / mode / operation), the WTRU may receive the indication in an RRC message (e.g., RRCSetup, RRCReconfiguration) or a RACH response message. In an embodiment, the WTRU may receive the indication in an updated SIB, which may be accessed by the WTRU after a certain configured duration (e.g., expiration of a timer) when sending an indication to the network. When a first trigger event for initiating an SRSp transmission is detected (eg, a change in mobility state, receiving a DL indication), the WTRU may transmit the SRSp using resources in the selected SRSp configuration.

[0236] If a first triggering event for initiating SRSp transmission is detected (e.g., a change in mobility state, receiving a DL indication) and if a second event (e.g., a change in mobility state) is detected, the WTRU may stop the first timer and SRSp transmission. When the WTRU detects the second event, it may start a second timer for a duration of D (e.g., for a configured period). If the second event is a semi-static event (e.g., the WTRU receives periodic data in DL) and / or the second event ends before expiration of the second timer, the WTRU may restart the first timer and / or resume SRSp transmission using the current SRSp configuration (e.g., the SRSp configuration associated with the closest SRSp Tx occasion). If the second event is a dynamic event (e.g., receipt of high priority / URLLC data, change in orbit / mobility state) and / or the second event ends after expiration of the second timer, the WTRU may reset the first timer (e.g., to T0). The WTRU may send an indication to the network indicating resetting the timer and / or starting SRSp transmission. The WTRU may transmit (e.g., transmit then) the SRSp using resources in the SRSp configuration associated with the Tx time occasion (e.g., reset time T0). If the second event corresponds to an interruption in transmission (e.g., receipt of a DL indication indicating stop of SRSp transmission), the WTRU may stop the first timer and SRSp transmission. If the second event is not detected, the WTRU may stop transmitting SRSp upon expiration of the first timer (e.g., for a configured duration associated with the INACTIVE / IDLE time, possibly until the start of the next Tx occasion).

[0237] An example of a WTRU transmitting SRSp-based detection of locations in a preconfigured positioning area is provided herein. The WTRU may transmit SRSp in one or more locations associated with a preconfigured positioning area (e.g., coverage area of ​​a set of TRPs / gNBs) using an SRSp configuration associated with the positioning area. The WTRU may select an SRSp configuration from a set of preconfigured SRSp configurations based on a positioning area in which the WTRU may be located and an expected positioning QoS (e.g., accuracy) to be achieved with measurements at TRPs in the positioning area. If the expected accuracy requirements cannot be met at a TRP, the WTRU may use an exceptional SRSp configuration (e.g., a high BW SRSp configuration) associated with at least some of the TRPs that may meet the expected positioning QoS.

[0238] The WTRU may receive configuration information (e.g., RRC_CONNECTED / INACTIVE / IDLE states) including one or more SRSp configurations including at least resources in a low-bandwidth SRSp configuration and a high-bandwidth SRSp configuration (e.g., exception SRSp configuration), scheduled time occasions (e.g., T1, T2, ..., Ti) at which the WTRU is expected to transmit the SRSp, one or more sets of TRPs (e.g., cell IDs) in a positioning area, where each set of TRPs may be associated with an SRSp configuration (e.g., the TRPs in a set may be configured by the LMF to make measurements of SRSp transmitted by the WTRU at different time occasions), or thresholds for the minimum / maximum number of TRPs that may be required to meet positioning accuracy requirements.

[0239] The WTRU may be transitioned or transitioned by the network to operate in a 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) to detect one or more TRPs and to determine radio conditions associated with the detected TRPs (e.g., RSRP measurements for RSs that may be in a spatial relationship with SRSp). The WTRU may perform measurements at least at the following time occasions: before, near, and at time T1.

[0240] If one or more detected TRPs match a configured set of TRPs (e.g., the IDs of the detected set of TRPs and the IDs of the configured set of TRPs are the same or differ by a count that may be less than a threshold count) and the number of detected TRPs with good RSRPs (e.g., the measured RSRP is greater than an RSRP threshold) is greater than a threshold for a minimum number of TRPs, the WTRU may select a low-bandwidth SRSp configuration associated with the detected TRP. The WTRU may transmit (e.g., transmit, then transmit) an SRSp using resources in the low-bandwidth SRSp configuration at a scheduled time occasion Ti. If one or more detected TRPs match a configured set of TRPs (e.g., the IDs of the detected set of TRPs and the IDs of the configured set of TRPs are the same or differ by a count that may be less than the threshold count) and the number of detected TRPs with good RSRPs is less than a threshold for the minimum number of TRPs, the WTRU may determine (e.g., possibly based on reception of a positioning SIB or pre-configured in the WTRU) a high-bandwidth SRSp configuration (e.g., an exceptional SRSp configuration) associated with the detected TRPs with good RSRPs. The WTRU may send an indication to the gNB indicating the IDs of the detected TRPs (e.g., the WTRU may send an indication via RACH-SDT / CG-SDT when operating in an RRC INACTIVE state, and the WTRU may send an indication via RACH / initial access message / RRCRequest or in a RACH occasion associated with a positioning message when operating in an RRC IDLE state). The WTRU may request to activate the high-bandwidth SRSp configuration. The WTRU may transmit an SRSp using resources in a high-bandwidth SRSp configuration (e.g., possibly after receiving an activation indication from the gNB). In an embodiment, the WTRU may receive the indication in a DL-SDT message from the network when operating in an INACTIVE state. In an embodiment, the WTRU may receive the indication in a RACH Response / RRCSetup / SIB Update message when operating in an IDLE state.

[0241] If the detected TRP does not match the configured set of TRPs (e.g., the IDs of the detected set of TRPs and the configured set of TRPs differ by a count that may be greater than a threshold count), the WTRU may send an indication to the gNB to request an updated SRSp configuration. The WTRU may transmit an updated SRSp using resources in the updated SRSp configuration (e.g., after receiving information about the updated SRSp configuration from the gNB).

[0242] An example of a WTRU transmitting a Tx scheduled time occasion and SRSp-based detection of a trigger event is provided herein. The WTRU may transmit an SRSp at the scheduled time occasion using an SRSp configuration associated with the time occasion. The duration difference between each time occasion may be an absolute pre-configured value or (for example, in this case) a variable relative value that may depend on the previous time occasion and / or the type of event detected by the WTRU. If an event is detected (e.g., if the WTRU deviates from an expected orbit or if measurements made of spatially related RSs are below an RSRP threshold), the WTRU may use an alternative SRSp configuration to improve accuracy.

[0243] Examples may include the following: The WTRU may receive configuration information including one or more of: 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-contiguous to achieve high accuracy), scheduled time occasions (e.g., T0, T1, T2, ...) at which the WTRU may be expected to transmit the SRSp, or an SRSp Tx duration D.

[0244] At a scheduled time occasion (e.g., a first scheduled time occasion (e.g., T0)), the WTRU may transmit an SRSp using resources from the low-bandwidth SRSp configuration. If a triggering event is detected by the WTRU (e.g., if the WTRU receives a low-precision indication from the network, if there is a change in the mobility state or orbit), the WTRU may stop SRSp transmission using the low-bandwidth SRSp configuration and / or start a timer that may run for duration D. The WTRU may send an indication to the network (e.g., gNB, LMF) to request to activate a high-bandwidth SRSp configuration. The WTRU may transmit an SRSp using resources from the high-bandwidth SRSp configuration until the timer expires (e.g., after receiving an activation / acknowledgement message from the network).

[0245] If the triggering event ends before the expiration of the timer, the WTRU may stop SRSp transmission using the high-bandwidth SRSp configuration when the event ends. If the triggering event ends after the expiration of the timer and / or before the start of a second scheduled time occasion (e.g., T1), the WTRU may stop SRSp transmission using the high-bandwidth SRSp configuration upon expiration of the timer. If the triggering event ends after the start of a subsequent scheduled time occasion (e.g., after T1), the WTRU may stop SRSp transmission using the high-bandwidth SRSp configuration upon expiration of the timer. The WTRU may start SRSp transmission using the high-bandwidth SRSp configuration at the start of the second scheduled time occasion (e.g., T1). The WTRU may (e.g., may start) a timer for duration D. The WTRU may stop SRSp transmission using the high-bandwidth SRSp configuration when the event ends and / or when the timer expires. The WTRU may resume SRSp transmission using resources from the low-bandwidth SRSp configuration until expiration of the timer (e.g., if 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.

[0246] As time progresses (e.g., for time occasions greater than Tn, where n>0), the WTRU may gradually decrease the density of time / frequency resources in the SRSp configuration during SRSp transmission. (e.g., in this case) the WTRU may receive scheduled Tx time occasions (e.g., T0, T1, T2) for SRSp transmission and / or an SRSp configuration associated with each timing. The WTRU may start a timer at the first Tx time occasion. 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. (e.g., on the other hand) the WTRU may continue transmitting at the next Tx time occasion when the processing duration for processing the event is less than a threshold. The WTRU may be configured with an SRSp transmission pattern (e.g., SRSp transmission at preconfigured timings and preconfigured time and / or frequency density). The WTRU may (e.g., may be) configured with a time window (e.g., configured with start / end times, duration) from the network (e.g., LMF, gNB) during which the WTRU sends a preconfigured SRSp transmission.

[0247] If there is a dynamic event that may cause the WTRU to stop SRSp transmission (e.g., DCI, MAC-CE, cancellation of SRSp transmission, event that prevents the WTRU from transmitting SRSp), the WTRU may pause SRSp transmission and resume transmission after the event (e.g., if the WTRU is configured to transmit SRSp with time density or periodicity N1 during initial transmission and transmit SRSp with time density or periodicity N2 after the initial transmission). The WTRU may transmit SRSp with density N1 (e.g., after resumption). If the WTRU is pre-configured with a pattern of SRSp transmission, the WTRU may determine to resume the transmission pattern or continue transmitting SRSp after the event based on at least one of the following conditions: (i) the WTRU may resume the transmission pattern if the duration of the dynamic event is greater than a threshold duration (e.g., if the duration is less than or equal to the threshold duration, the WTRU may continue transmitting after the event); or (ii) the WTRU may continue transmitting if the event is semi-static (e.g., periodic reception of DL / UL signals, monitoring of SSB and / or DL ​​signals / channels, an event configured by RRC or LPP, etc.).

[0248] The WTRU may determine to end transmission at the end of a configured time window. The WTRU may receive a configuration from the network via a DCI, MAC-CE, RRC, or LPP message. The WTRU may end SRSp transmission when the WTRU is configured to transition from RRC_INACTIVE mode to RRC_CONNECTED mode.

[0249] 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 the first positioning area (e.g., a default positioning area), the WTRU may transmit SRSp using the SRSp configuration (e.g., a default SRSp configuration) of the first positioning area. If the WTRU is located in a cell outside the first positioning area (e.g., outside the default positioning area), the WTRU may send 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).

[0250] In an embodiment, the WTRU may be configured to perform at least one of the following: The WTRU may receive configuration information (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 a low power operation (e.g., an INACTIVE or an idle operation / state) or transitioning from CONNECTED to INACTIVE) from, for example, a base station in a first cell. The configuration information may indicate different SRSp configurations associated with different positioning areas, e.g., a first SRSp configuration for the first positioning area and a second SRSp configuration for the second positioning area. The configuration information may indicate different cell ID sets associated with different positioning areas, e.g., a first cell ID set for the first positioning area and a second cell ID set for the second positioning area. The WTRU may transmit a first SRSp using a first (e.g., default) SRSp configuration (e.g., implemented during low power operation (e.g., based on receiving an RRCRelease message) and before detecting the second cell). The WTRU may transmit the first SRSp using the first SRSp configuration based on detecting a cell ID that is within the first cell ID set. The WTRU may select (e.g., detect) the second cell. The WTRU may determine a positioning area in which the WTRU is located (e.g., based on a received / determined cell ID associated with the second cell). The WTRU may transmit an SRSp (e.g., in the second cell) using the first (e.g., default) SRSp configuration if the detected second cell ID is within the first (e.g., default) positioning area. If the detected second cell ID is not within 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 within a 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 configuration information / first association information).The WTRU may determine an SRSp configuration (e.g., a second SRSp configuration) to use in the second positioning area based on the SRSp configuration (e.g., the second SRSp configuration) being associated with the second positioning area (e.g., determined from configuration information / second association information) (e.g., based on a 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 (e.g., the second SRSp configuration) associated with the second positioning area. The WTRU may receive a requested (e.g., second) SRSp configuration activation indication (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 a third SRS configuration activation indication (e.g., in an RRCResume message, an RRCReconfig message, or a MAC CE) from the second cell. The WTRU may transmit the SRSp using the SRSp configuration activated or indicated by the second cell.

[0251] 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 (e.g., may be activated) the first positioning area. 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.). A configuration in the set of one or more SRSp configurations may be deactivated (e.g., at a time associated with receiving the configuration information). The configuration information may include a first (e.g., default) positioning area (e.g., may be, may include, or may be associated with an area ID) (e.g., associated with a first SRSp configuration) and a first cell ID (e.g., a cell ID of a cell in the first positioning area) set in the first (e.g., default) positioning area. The configuration information may include first association information indicating an association between the positioning area (e.g., may be, may include, or may be associated with an area ID) and a cell ID set (e.g., may include a second cell ID set associated with a second positioning area). The configuration information may include second association information indicating an association between the positioning area (e.g., may be, may include, or may be associated with an area ID) and an SRSp configuration (e.g., may be, may include, or may be associated with a configuration ID) (e.g., may include that a second positioning area is associated with a second SRSp configuration).

[0252] If the WTRU selects a second cell, the WTRU may (re)select the second cell if the WTRU moves from the first cell to the second cell (e.g., the WTRU may select the second cell if the WTRU detects the cell ID of the second cell).

[0253] When the WTRU determines a positioning area in which the WTRU is located (e.g., in which a second cell is located), the WTRU may determine the positioning area based on a detected second cell ID (e.g., PCI) in an SSB received from the second cell. In an embodiment, the WTRU may determine that the second cell is located in the second positioning area based on the detected second cell ID being within a second cell ID set associated with the second positioning area.

[0254] For a WTRU sending an instruction to a second cell to request activation of an SRSp configuration (e.g., a second SRSp configuration) associated with a second positioning area (e.g., if the detected second cell ID is not in the default positioning area), the WTRU may send the instruction in an RRCResumeRequest message, possibly using SDT resources (e.g., RACH-SDT, CG-SDT). The ResumeRequest message may include a cause value / instruction indicating a request to activate an SRSp configuration without transitioning to a CONNECTED state. For a WTRU sending an instruction to a second cell to request activation of an SRSp configuration associated with a second positioning area (e.g., if the detected second cell ID is not in the default positioning area), the WTRU may send an ID of an SRSp configuration associated with a positioning area (e.g., a second positioning area) in which the WTRU may be located. The WTRU may send in the instruction or in another instruction request to deactivate the first (e.g., default) SRSp configuration.

[0255] FIG. 2 illustrates a WTRU in low power operation (e.g., INACTIVE state) selecting a positioning area-specific SRSp configuration to perform an SRSp transmission. The WTRU may select a positioning area-specific SRSp configuration to perform an SRSp transmission based on a cell associated with a positioning 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) positioning area or performs cell (re)selection, the WTRU may transmit an SRSp transmission using the first (e.g., default) SRSp configuration. For example, if the WTRU is located in a cell (e.g., cell 4) outside the default positioning area or performs cell (re)selection, the WTRU may send a request to the network to activate a second SRSp configuration associated with a second positioning area (e.g., pre-configured).

[0256] The WTRU may send a request to update the validity condition of the SRSp configuration. A WTRU in low power operation (e.g., INACTIVE state) may send an instruction to the network to update the validity condition (e.g., TA timer) associated with the SRSp configuration when a configured positioning event is detected (e.g., detection of an updated cell ID due to cell reselection or mobility). In an embodiment, the WTRU may be configured to perform at least one of the following: The WTRU may receive (e.g., in a RRCRelease message) configuration information including 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 transmit an SRSp using the SRSp configuration (e.g., the first SRSp configuration). If the validity condition has not expired when the WTRU detects the updated TRP / cell ID (e.g., outside the positioning area), the WTRU may send an indication to the gNB (e.g., in an RRC message or MAC CE using SDT resources) indicating a request to extend the validity condition, receive an indication from the gNB (e.g., in an RRC message or DL ​​MAC CE) indicating an extension of the validity condition, and / or transmit SRSp using an SRSp configuration (e.g., second SRSp configuration) in the existing cell and / or the updated cell. If the validity condition has expired when the WTRU detects the updated TRP / cell ID (e.g., outside the positioning area), the WTRU may release the SRSp configuration (e.g., first SRSp configuration), send an indication to the gNB for a request for an updated (e.g., second) SRSp configuration (e.g., using SDT resources), receive the updated (e.g., second) SRSp configuration from the gNB, and / or receive SRSp using the updated (e.g., second) SRSp configuration.

[0257] The WTRU may select an SRSp configuration based on the detectable TRP. The WTRU may determine a set of one or more TRPs and SRSp configurations to use to meet a positioning measurement accuracy requirement based on the number of TRPs detected using RSRP measurements of SSBs / RSs received from TRPs above the RSRP threshold. In an embodiment, 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., a minimum number of TRPs detectable to meet an accuracy requirement), or an RSRP threshold. The WTRU may perform RSRP measurements of SSBs / RSs received from the detected TRPs. The WTRU may select the first SRSp configuration (e.g., low density) and / or transmit SRSp using the first (e.g., default) SRSp configuration if the number of detected TRPs with RSRPs above the RSRP threshold is greater than the TRP count threshold. The WTRU may select a second (e.g., updated) SRSp configuration (e.g., high density) if the number of detected TRPs having an RSRP above the RSRP threshold is less than the TRP count threshold, send 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 transmit an SRSp using the second (e.g., updated) SRSp configuration if an activation indication is received.

[0258] The WTRU may select an SRSp configuration based on the expected measurement accuracy in the 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 the expected measurement accuracy in the positioning area in which the WTRU is located. In an embodiment, the WTRU may be configured to perform at least one of the following: The WTRU may receive (e.g., in an RRCRelease message) configuration information including 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. 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 first SRSp configuration (e.g., low density) and / or transmission of SRSp using resources in the first SRSp configuration (e.g., when an activation indication and an SRSp activation time window are received, as the case may be) if the RSRP measurement is above an 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) and transmission of SRSp using resources in the second (e.g., updated) SRSp configuration (e.g., when an activation indication and an SRSp activation time window are received, as the case may be). The WTRU may send a deactivation indication to the gNB to terminate or release the first SRSp configuration (e.g., after the activation time window expires).

[0259] Examples for supporting positioning using Mobile Terminated Small Data Transmission (MT-SDT) are provided herein. The WTRU may be configured with MT-SDT to support positioning in low power operation (e.g., power saving or INACTIVE / IDLE states / modes / operations).

[0260] The WTRU may be configured with configurations and / or resources associated with MT-SDT to support at least one of DL-based, UL-based, DL and UL-based positioning, or RAT-independent positioning embodiments (e.g., any RAT-independent positioning example (e.g., GNSS)) when in low power operation (e.g., RRC INACTIVE / IDLE state). MT-SDT may refer to any procedures, configurations, and / or functions that may be supported by the WTRU and / or the network for DL ​​reception using SDT resources (e.g., RA-SDT, CG-SDT). Such DL reception may include at least one of data / control messages, assistance data, configuration information, or any LPP / LCS messages when supporting MT-SDT and when transitioning to the RRC INACTIVE / IDLE state (e.g., before and / or after transitioning). In an embodiment, the MT-SDT may include at least one of any of the measurement configurations, PRS, or other reference signals (e.g., TRS, CSI-RS) that the WTRU may receive in the INACTIVE / IDLE state. When the WTRU is operating in the INACTIVE / IDLE state (e.g., after the MT-SDT is triggered / activated as the case may be), it may receive at least one of DL data / control messages (e.g., LPP / LCS messages, activation / deactivation indications), or PRS (e.g., in the case of positioning). The activation or deactivation commands may be associated with a measurement gap or PRS processing window for processing measurements made on the PRS.

[0261] In an embodiment, the MT-SDT may be configured together with the MO-SDT, both the MO-SDT and the MT-SDT may be configured simultaneously in the WTRU (e.g., via RRCRelease), or the MT-SDT may be activated when the MO-SDT is activated. In an embodiment, the MT-SDT may be configured and / or activated independently of the MO-SDT. In an embodiment, the MT-SDT may be triggered and / or activated (e.g., explicitly triggered / activated) when the WTRU receives a configuration and / or an indication (e.g., either a configuration and / or an indication) associated with activating the MT-SDT. In an embodiment, the MT-SDT may be activated / triggered (e.g., implicitly activated / triggered) when the WTRU receives a DL data / control message (e.g., a paging message) or at least one of the PRS if in the INACTIVE state. The WTRU may receive (e.g., in both cases) DL data / control messages or at least one of the PRSs over the MT-SDT if (e.g., after) the MT-SDT is activated / triggered (e.g., explicitly or implicitly).

[0262] 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., a serving base station / cell or LMF) via one or more of an RRC message, interaction with the MO-SDT, a paging message, or an indication / request initiated by the WTRU.

[0263] For RRC messages, the WTRU may receive a configuration associated with MT-SDT in an RRC RELEASE message (e.g., with a suspend configuration) if it transitions to low power operation (e.g., RRC INACTIVE state). The WTRU may receive the MT-SDT configuration via an RRC RECONFIGURATION message and / or an RRC RESUME message (e.g., possibly when in the INACTIVE state). If it receives an RRC RECONFIGURATION / RRC RESUME message for MT-SDT, the WTRU may receive an indication / flag indicating to remain in low power operation (e.g., INACTIVE state). In an embodiment, the WTRU may receive a paging message, which may include the MT-SDT configuration in the RRC RECONFIGURATION / RRC RESUME message received (e.g., with the paging message). In an embodiment, the WTRU may receive an RRC RECONFIGURATION / RRC RESUME message (e.g., after) the paging message (which may include the MT-SDT configuration). The WTRU may receive the MT-SDT configuration via an RRC RECONFIGURATION if it is in the RRC CONNECTED state. The MT-SDT configuration in the WTRU may be activated (eg, may then be activated) if (eg, after) receiving an activation indication via an RRC release message and / or a paging message.

[0264] With respect to interrelationship with MO-SDT, if the WTRU is configured with an 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 with MO-SDT resources), the WTRU may use all or a subset of the configuration associated with MO-SDT for MT-SDT. In an embodiment, when MO-SDT is triggered (e.g., when the WTRU performs a first / initial transmission using the 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 messages / signaling (e.g., in RRC, MAC CE, or DCI)).

[0265] In the case of paging messages, the WTRU may receive an indication to activate / deactivate an MT-SDT configuration or a pre-configured MT-SDT configuration if it receives one or more paging messages. In an embodiment, the paging message received by the WTRU may include the WTRU ID in the DCI (e.g., I-RNTI, paging I-RNTI) and / or possibly a flag / indication indicating the presence of an MT-SDT configuration. If such a 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 embodiment, if (e.g., after) a paging message is received on one or more paging occasions, which may indicate the presence of an MT-SDT configuration for the WTRU, the WTRU may initiate a RACH procedure by transmitting a RACH preamble. The WTRU may receive (e.g., may then receive) an MT-SDT configuration or 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 embodiment, if configured with an SDT resource (e.g., CG-SDT) and if (e.g., after receiving) a paging message, the WTRU may send a request message (e.g., RRC Request or RRC Resume) to at least one of: begin an SDT, request an MT-SDT configuration, or (de)activate a pre-configured MT-SDT. The WTRU may receive (e.g., may then receive) an MT-SDT configuration or (de)activation indication for a pre-configured MT-SDT in the DL (e.g., via RRC, MAC CE, DCI). Such UL and DL messages may be transmitted / 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 (eg, RRC or PDCCH signaling) that indicates to the WTRU to transition to a different RRC state or to perform a (eg, possibly associated) RRC resumption procedure.A WTRU configured with a DL SDT may monitor a subset of paging occasions (or a subset of P-RNTIs), and such a partition may be configured and associated with the reception of a DL SDT or an initiated DL SDT procedure.

[0266] For WTRU initiated indication / request, the WTRU may receive MT-SDT configuration for receiving data / control messages in DL if in low power operation (e.g., INACTIVE state) when sending indication or request message (either) in RRC_CONNECTED or RRC_INACTIVE state (e.g., in SDT). 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), a request for configuring / activating measurement gaps, or a request / assistance information for configuring configured grant / SPS (e.g., payload size and / or periodicity for receiving periodic assistance data / LPP messages from the 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., positioning as described above) related configurations, etc.), part of an RRC release message, part of a paging message, or via broadcast signaling. The WTRU may request such configuration, or a subset thereof, when performing cell reselection, gNB reselection, RAN notification area crossing, or tracking area crossing.

[0267] The WTRU may activate resources configured for UL SDT (e.g., CG-SDT resources) when it receives an indication to begin a DL SDT procedure (e.g., possibly conditional on receiving a TA command or conditional on having UL timing synchronization (e.g., TA timer or CG-TAT implementation)). In an example, the WTRU may activate CG-SDT resources when it receives (e.g., following) a paging indication / trigger indicating the start of a DL SDT procedure. The WTRU may start the CG-TAT when it receives a paging indication / trigger indicating the start of a DL SDT procedure.

[0268] The configuration information associated with the MT-SDT may be received by the WTRU using at least one of a radio bearer configuration, a radio resource configuration, a validity condition, a timing advance (TA) / TA timer configuration, an RSRP difference threshold configuration, a positioning-related configuration, a priority value, a traffic-related configuration, or a DRX configuration.

[0269] 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., that may be used after MT-SDT is triggered / activated). The WTRU may be configured with one or more parameters associated with the DRBs / SRBs for MT-SDT, including parameters associated with sublayers / entities of the DRBs / SRBs, such as service data adaptation protocol (SDAP), PDCP (e.g., ROCH, coding / encryption, 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 for TB), or physical layer (PHY).

[0270] For radio resource configuration, the WTRU may be configured with one or more RA-SDT and / or CG-SDT configurations. The WTRU may use the RA-SDT and / or CG-SDT configurations to receive DL data (e.g., in a PDSCH) when (e.g., after) MT-SDT is activated. The RA-SDT configuration may include at least parameters corresponding to ID, payload size, amount of data, 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, starting offset timeslot, periodicity, payload size, etc. that may 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 (e.g., after) the MT-SDT is triggered and / or activated, including at least one of a BWP (e.g., initial, non-initial), carrier, beam, or time / frequency resource pool.

[0271] With respect to 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 area validity (e.g., list of cells / cell IDs) and / or time validity (e.g., duration / window), and the corresponding MT-SDT configuration may be assumed to be valid for use by the WTRU. In an embodiment, the validity condition indicating the validity of the MT-SDT configuration may include a reception count. The WTRU may be configured with (e.g., in this case) N receptions associated with MT-SDT. The MT-SDT configuration may be activated, for example, during the first reception and / or deactivated after the nth reception.

[0272] For timing advance (TA) / TA timer, the WTRU may be configured with a TA timer associated with an MT-SDT configuration that may be used to determine if 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 release the MT-SDT configuration. If a TA command is received, the WTRU may restart the TA timer associated with the MT-SDT.

[0273] For RSRP difference thresholds, the WTRU may be configured with one or more RSRP difference thresholds associated with an MT-SDT configuration that may be used to determine if MT-SDT is valid for use. In an embodiment, if the RSRP difference measured between a DL signal that transitions the WTRU to an INACTIVE state (e.g., an RRC release message) and another DL signal (e.g., any DL signal associated with MT-SDT, as the case may be) is greater than or less than a threshold, the WTRU may stop / suspend using the associated MT-SDT configuration and / or release the MT-SDT configuration.

[0274] 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., SRB) for receiving at least one of one or more positioning related messages (e.g., LPP / LCS messages, one or more (de)activation indications, or one or more positioning configurations (e.g., SRSp and / or PRS configurations)).

[0275] For the priority value, the WTRU may receive priority values ​​associated with one or more MT-SDT configurations. The WTRU may determine (e.g., based on the associated priority value) whether or which MT-SDT configuration to use for receiving DL data (e.g., during a DRX cycle when in INACTIVE / IDLE state). The priority value may be associated with a PRS resource configured for the WTRU. In an embodiment, 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 low compared to other DL signals or channels, the WTRU may determine to postpone processing of measurements made 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 made on the PRS.

[0276] For traffic-related configurations, the WTRU may be configured to receive data in DL with different payload sizes over the MT-SDT. The WTRU may (e.g., may be configured) with different MT-SDT configurations that 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, possibly based on an indication received from the network (e.g., a paging message that may indicate an ID of the MT-SDT configuration to use or information about the payload size of the DL data). In an embodiment, the WTRU may be configured to receive periodic or semi-persistent data in DL over the MT-SDT. The WTRU may (e.g., may be configured) with different MT-SDT configurations that may be associated with different periodicity values. The WTRU may (e.g., may be configured) with different parameters associated with receiving periodic / semi-persistent data over the MT-SDT (including, e.g., start / stop offset times and duration / window). The WTRU may select / use a suitable MT-SDT configuration for receiving DL data within a certain periodicity (e.g., in this case) (e.g., possibly based on an indication received from the network (e.g., a paging message)).

[0277] For DRX configurations, the WTRU may be configured with one or more DRX configurations when in low power operation (e.g., INACTIVE / IDLE mode / state). Such DRX configurations may be aligned with MT-SDT resources / configurations (e.g., the periodicity of DRX ON / active time may be aligned with the CG-SDT periodicity of MT-SDT). The WTRU may (e.g., may be) configured with different DRX parameters, including DRX cycle duration, ON duration, and inactivity timer, that may be aligned with MT-SDT resources for receiving DL data when in INACTIVE / IDLE mode / state.

[0278] In an embodiment, when starting / activating an MT-SDT for DL ​​reception (e.g., a first DL reception), the MT-SDT may remain active for another DL reception (e.g., further DL reception) until, for example, an explicit indication (e.g., an RRC reconfiguration message) or an implicit indication (e.g., the WTRU moves to a new cell, a TA timer expires) is received from the network indicating deactivation of the MT-SDT configuration. The MT-SDT configuration may be reactivated / resumed if an indication associated with the MT-SDT (e.g., a TA command) is received from the network. In an embodiment, the configured and / or activated MT-SDT configuration may remain activated for further DL reception at least until an indication to release the MT-SDT configuration (e.g., an RRC release) and / or an indication to transition from an RRC INACTIVE state to an RRC CONNECTED state (e.g., an RRC resume request) is received from the network.

[0279] If a DL SDT TB is received (e.g., after receiving a DL SDT TB), the WTRU may monitor for reception of another (e.g., subsequent) DL SDT TB. The subsequent DL SDT TB may be received on a configured DL CG-SDT resource, RA-SDT resource, or as a DL transmission (e.g., a subsequent DL transmission) for a scheduled PDSCH DL assignment. The WTRU may monitor the PDCCH resource, search space, or CORSET for reception of another (e.g., subsequent) DL SDT TB or assignment.

[0280] In an embodiment, the WTRU may monitor (e.g., conditionally monitor) another (e.g., subsequent) DL SDT if at least one of the following is met: a TB configured for the DL SDT is multiplexed with a TB of the initial DL SDT; no RRC messages are present in the initial DL SDT TB regardless of whether an RRC message (e.g., an RRC release message) is multiplexed therein; or the TB size of the initial DL SDT TB is smaller or larger than a configured threshold.

[0281] An embodiment of a WTRU receiving indications / information about positioning via MT-SDT when in low power operation (e.g., RRC INACTIVE / IDLE mode) is provided herein. The WTRU may receive one or more indications / messages (e.g., LCS / LPP messages) associated with positioning from the network (e.g., RAN and / or LMF) while operating in RRC INACTIVE / IDLE mode. Such positioning messages may include at least one of those related to MT-LR, suspended MT-LR, or MO-LR positioning services. The positioning message / instruction may be received by the WTRU via MT-SDT (e.g., when MT-SDT starts / runs due to a previous DL SDT reception or UL SDT transmission). In an embodiment, receipt of the positioning message / instruction may trigger / activate a pre-configured MT-SDT configuration in the WTRU (e.g., when MT-SDT does not start).

[0282] When configured with MT-SDT and / or when a pre-configured MT-SDT configuration is activated, the WTRU may receive one or more of the following messages / indications / configurations related to positioning when in INACTIVE / IDLE mode: LCS messages, LPP messages, or RAN related configurations.

[0283] The LCS messages may include messages (e.g., any messages) related to MT-LR, pending 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.).

[0284] The LPP message may include one or more of an LPP request for capability information, an LLP to provide assistance data, or an LPP request for location information. For an LLP request for capability information, the WTRU may receive a request to support at least one of the positioning embodiments, i.e., DL-based, UL-based, or DL ​​and UL-based. For an LPP providing assistance data, the WTRU may receive one or more PRS and / or SRSp configurations to support at least one of the positioning embodiments (e.g., as described herein). Such configurations may be received in an LPP assistance data message and / or in an RRC message. The WTRU may (e.g., may receive) assistance data (e.g., TRP / gNB location information, beam direction, boresight angle, correction information) based on whether WTRU-based positioning or WTRU-assisted positioning is requested by the network. For an LPP request for location information, the WTRU may receive an LPP message from the LMF, possibly with a response time indicating at least one of the duration for performing measurements, processing the measurements, or reporting the results to the network.

[0285] The RAN-related configuration may include at least one of an SRSp resource / configuration, an activation / deactivation indication for an SRSp / PRS configuration, a measurement gap (MG) configuration, or correction information. For an SRSp resource / configuration, the WTRU may receive at least one of an SRSp configuration (e.g., aperiodic SRSp, semi-persistent SRSp, or periodic SRSp) or parameters associated with the SRSp configuration (e.g., ID, start offset timeslot, periodicity). The configuration information may be received in an RRC message (e.g., RRC release), MAC CE, and / or DCI. For an SRSp configuration, the WTRU may be configured with activation / deactivation rules to determine when to start and stop SRSp transmission if (e.g., after) receiving an SRSp configuration. In an embodiment, the WTRU may start transmitting SRSp (e.g., using the configured semi-persistent or periodic SRSp resources) after (e.g., immediately after) receiving the associated SRSp configuration (e.g., without any explicit activation indication). The WTRU may stop SRSp transmission (e.g., for periodic or semi-persistent SRSp) upon expiration of (any of) the validity conditions (e.g., TA, RSRP difference threshold) associated with the MT-SDT or MO-SDT.

[0286] For an SRSp / PRS configuration activation / deactivation indication, the WTRU may start / stop transmitting an SRSp (e.g., semi-persistent SRSp or aperiodic SRSp) based on receiving an explicit or implicit indication from the network. Such a (de)activation indication may be received by the WTRU via an RRC message, a MAC CE, or an MT-SDT in a DCI.

[0287] For measurement gap (MG) configuration, the WTRU may receive at least one of a configuration associated with the MG or an instruction to activate / deactivate a pre-configured MG via the MT-SDT. Such MG-related configuration and / or instruction may be received by the WTRU when (e.g., after) sending a request for MG indication while in the CONNECTED or INACTIVE state (e.g., via the UL SDT). Such MG-related configuration and / or instruction received via the MT-SDT may be used to perform DL-PRS measurements when in the INACTIVE / IDLE state.

[0288] For correction information, the WTRU may receive correction information such as a timing error group (TEG) via the MT-SDT. Such correction information may be received by the WTRU when (e.g., after) transmitting a request indication while in the CONNECTED or INACTIVE state (e.g., via the UL SDT). Such correction information may be used by the WTRU to determine the location of the WTRU when operating in a WTRU-based positioning mode.

[0289] The WTRU may receive an LPP request for WTRU capability information and / or LPP assistance data that may be piggybacked when receiving an LCS request over the MT-SDT. The WTRU may receive one or more of the LPP messages (e.g., LPP messages described herein) in either a single MT-SDT reception (e.g., a single NAS / LPP message) or multiple MT-SDT receptions (e.g., multiple NAS / LPP messages) (e.g., in this case).

[0290] Receipt of a message / indication (e.g., any of the messages / indications described herein) may result in starting / activating MT-SDT for a WTRU in INACTIVE state if MT-SDT is configured in the WTRU and / or not previously started. In an embodiment, when MT-SDT is started / activated (e.g., after MT-SDT is started / activated), the WTRU may send a request message to modify / update the activated MT-SDT configuration or a request to release the MT-SDT configuration to the base station (e.g., when transitioning from INACTIVE to CONNECTED state, as the case may be). Such a request to modify and / or release MT-SDT may be sent by the WTRU to the base station due to at least one of the following triggers: traffic / QoS requirement, DRX misalignment, or positioning requirement.

[0291] For traffic / QoS requirements, the WTRU may send a request indication to change the MT-SDT to meet certain QoS requirements (e.g., latency, data rate) when receiving data in the DL while in INACTIVE / IDLE state. The WTRU may (e.g., may send) a request indication when it detects a change to the QoS of data received in the DL while in INACTIVE / IDLE state (e.g., latency increases above / below a threshold, bit rate decreases above / below a threshold).

[0292] For DRX misalignment, the WTRU may send a request indication to change the MT-SDT if it detects a misalignment (e.g., any misalignment) between data reception in the DL during the INACTIVE / IDLE state and the DRX configured in the WTRU.

[0293] For positioning requirements, the WTRU may send a request indication to change the MT-SDT if it detects a change associated with positioning, including at least one of a change to the achievable positioning accuracy, a change to the PRS / SRSp configuration used, or a change to the MG configured in the WTRU for performing positioning measurements.

[0294] In an embodiment, the WTRU may receive an activation / deactivation command for SP-SRSp transmission or associated positioning measurement and reporting procedures during a DL SDT procedure (e.g., part of a PDSCH payload or part of an MT-SDT configuration). The WTRU may activate / deactivate SP-SRSp transmission or associated positioning measurement and reporting procedures if it receives a paging message (e.g., indicated as part of the paging message itself or as part of a PDCCH that schedules the paging message), possibly associated or not associated with a DL SDT. In an embodiment, the WTRU may activate / deactivate SP-SRSp transmission or associated positioning measurement and reporting procedures if it receives a PDCCH that includes the WTRU's P-RNTI or the WTRU's ID (e.g., if the paging message is associated with a DL SDT, possibly).

[0295] In an embodiment, the WTRU may deactivate or activate the SP-SRSp or related positioning measurement and reporting procedures if a configured timer expires. The WTRU may reset such a timer if (e.g., every time) it receives a response or DL ​​transmission from the network (e.g., any DL transmission such as PRS, DL SDT TB, or PDCCH).

[0296] Examples of WTRU behavior / actions associated with positioning based on whether MT-SDT is configured and / or started are provided herein. In an example, the WTRU may determine the positioning examples that may be supported (e.g., DL-based, UL-based, DL&UL-based, or MT-LR / reserved MT-LR) and / or indicated to the network (e.g., to the LMF) (e.g., possibly in the WTRU capability information) based on whether MT-SDT and / or MO-SDT are configured and / or activated in the WTRU. In an example, the WTRU may indicate that the WTRU supports MT-LR and / or reserved MT-LR positioning during low power operation (e.g., INACTIVE state) if both MO-SDT and MT-SDT are configured and / or activated in the WTRU. In an example, the WTRU may indicate that the WTRU supports only reserved (e.g., reserved) MT-LR if MO-SDT (e.g., only MO-SDT) is configured and / or activated.

[0297] In an embodiment, the WTRU may determine whether / which LPP messages to send to the network and / or which corresponding LPP messages to receive based on whether the MT-SDT is configured and / or activated. In an embodiment, the WTRU may determine to send a request for assistance data to the network when the MT-SDT is configured and / or activated because the WTRU may receive corresponding LPP assistance data via the MT-SDT.

[0298] In an embodiment, when the WTRU is operating in the INACTIVE state to receive paging messages or DL ​​data (e.g., positioning information), it may determine whether to perform PDCCH monitoring (e.g., possibly during the DRX ON duration) based on whether MT-SDT is configured and / or activated. In an embodiment, when the WTRU sends an LCS / LPP request message (e.g., request for assistance data) to the network, the WTRU may assume that corresponding DL data (e.g., LPP assistance data) is received by the WTRU. The WTRU may skip monitoring the PDCCH to receive DL data (e.g., any DL data) in the PDSCH (e.g., if MT-SDT is not configured / activated).

[0299] In an embodiment, the WTRU may determine whether to receive / skip a DL message associated with positioning (e.g., a periodic LPP message) based on resources associated with an MT-SDT (e.g., RA-SDT, CG-SDT) configured in the WTRU. The WTRU may skip receiving some DL data (e.g., if determining the payload size or periodicity of DL data expected to be received is not aligned with resources associated with the configured and / or activated MT-SDT).

[0300] Provided herein are examples of a WTRU that determines and sends instructions to the network regarding attributes of expected DL positioning information based on a configured MT-SDT. The WTRU may determine and / or provide assistance information / instructions to the network to ensure that DL data (e.g., possibly associated with positioning (e.g., LPP / LCS messages)) can be received with resources and / or configurations associated with the MT-SDT.

[0301] In an embodiment, if the payload size of the 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 remaining in low power operation (e.g., INACTIVE state). If the 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 not be sufficient and / or may not be properly aligned with the time occasion. The WTRU may be transitioned to the CONNECTED state (e.g., in this case) to receive the LPP / LCS message (e.g., possibly resulting in additional latency or signaling overhead).

[0302] In an embodiment, to receive data having certain traffic characteristics over the MT-SDT, the WTRU may provide assistance information to the network (e.g., a base station and / or an LMF). The assistance information may be provided to recognize data expected to be received by the WTRU when in an INACTIVE state and to configure and / or trigger the MT-SDT. The WTRU may request assistance information from the network. The assistance information may include at least one of traffic information or segmentation-related information.

[0303] For traffic 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.

[0304] For segmentation related information, the WTRU may provide information / indication / flag on whether higher layer (e.g., LPP) segmentation is supported in DL and / or UL. Based on such information, the WTRU may receive one or more pre-configured MT-LR configurations and / or an indication of which MT-LR configuration to activate / use when receiving a segmented packet data unit (PDU). The WTRU may (e.g., may provide) information related to at least one of an ID associated with a segmented PDU, a number of segments expected in DL per LPP / LCS message / PDU, an expected / average payload size per segmented PDU, or a latency associated with delivering one or more segmented PDUs.

[0305] The WTRU may provide assistance information to the network (e.g., may provide any of the assistance information) periodically (e.g., with a preconfigured periodicity) and / or when triggered by some event (e.g., upon detecting a change in traffic, a change in measurements, and / or mobility that may result in a change in any of the existing MT-SDT configurations).

[0306] In an embodiment, the WTRU may determine attributes of positioning information to be received over the MT-SDT, including payload size and / or periodicity of the expected positioning information (e.g., periodic assistance data), based on a configuration (e.g., periodic resources or data volume thresholds associated with the CG-SDT) that may be associated with the MT-SDT (e.g., a signaling radio bearer (SRB) of the MT-SDT).

[0307] In an embodiment, the WTRU may determine whether the positioning information (e.g., carried in a non-access stratum (NAS_message)) should be segmented into one or more segments. Such a determination may be based on a data volume threshold configuration associated with an SRB configured in the WTRU for receiving the positioning information in the DL. The LMF may segment the positioning information into different segments, which may be below the configured data volume threshold (e.g., in this case), such that the segmented data may be delivered over the MT-SDT. In an embodiment, the WTRU may determine a periodicity (e.g., LMF) to be used by the network when delivering periodic positioning information (e.g., periodic LPP assistance data, or periodic ACK / NACK status indication in case the WTRU transmits a periodic report) based on a periodicity configured for resources associated with the MT-SDT (e.g., CG-SDT). In an embodiment, the WTRU may determine the number of segments to be applied and / or the payload size of a segment (e.g., each segment) when delivering segmented positioning information based on a configured resource associated with the MT-SDT (e.g., CG-SDT). In an embodiment, the WTRU may determine the number of segments to be applied by the LMF when sending segmented data in the DL based on a latency requirement associated with a positioning service configured in the WTRU and / or an expected latency for receiving DL data using MT-SDT resources configured in the WTRU.

[0308] The WTRU may send an indication / request to the network (e.g., via an LPP message to the LMF) for the determined attributes of the positioning information to be used when sending the positioning information in the DL (e.g., periodicity, payload size, whether to segment, number of segments to be used). In an embodiment, when determining the attributes of the positioning information expected in the DL, the WTRU may send an indication to the network (e.g., via RRC, MAC CE, UCI to the base station, possibly in CONNECTED / INACTIVE state). The indication may request an MT-SDT (e.g., a new MT-SDT) or modify / update an existing MT-SDT configuration, so that the MT-SDT configuration may be aligned with the expected reception of the positioning information in the DL. In an embodiment, when sending an indication to the network (e.g., to a base station via RRC, MAC CE, UCI, possibly in CONNECTED / INACTIVE state) about the determined attributes of the positioning information expected in the DL, the WTRU may receive a DRX configuration (e.g., a new / updated DRX configuration) to use while in the INACTIVE / IDLE state that may be consistent with the reception of the positioning information expected in the MT-SDT and / or DL.

[0309] An example of a WTRU receiving positioning information in 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 an 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) to carry and / or deliver positioning information using MT-SDT. Different SRBs configured in the WTRU for MT-SDT may be configured with one or more data volume thresholds associated with different types of positioning information.

[0310] The data volume threshold may be used to resume an SRB (e.g., SRB2) configured for MT-SDT when triggered by the arrival of a higher layer indication (e.g., indicating expected reception of positioning information). In an embodiment, the WTRU may send an indication to the network to request resuming and / or activating SRB2 to receive RRC and / or NAS messages in MT-SDT if 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 data volume threshold may be set by the LMF or gNB. An approach (e.g., a similar approach) used to receive positioning information using SDT when the WTRU is in INACTIVE state may be applicable (e.g., may be similarly applicable) when the WTRU is in IDLE state.

[0311] In an embodiment, the WTRU may be configured with one or more SRBs (e.g., that may be used to carry and / or deliver positioning information over the MT-SDT) based on a size of the positioning information determined by the WTRU. The WTRU may be configured with a data volume threshold corresponding to the SRB (e.g., in this case) based on an indication / information (e.g., assistance information) sent by the WTRU to the network. The indication / information may indicate a size of the positioning information to be carried or expected to be received using the MT-SDT. In an embodiment, 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 when sending an indication (e.g., capability information, LCS / LPP message) to the network. The WTRU may send an indication of the size of the positioning information to the gNB, for example, in an RRC message, MAC CE, or UCI. The WTRU may send an indication to the gNB when in the CONNECTED state or during or after transition to the INACTIVE state (e.g., via the UL SDT). If configured with a corresponding data volume threshold, the WTRU may receive (eg, may then receive) positioning information in an associated SRB (eg, SRB2) using the MT-SDT.

[0312] In an embodiment, the SRBs configured in the WTRU for MT-SDT (e.g., SRB1, SRB2) may be associated with different data volume thresholds for each SRB, and at a given time (e.g., any given time), at least one data volume threshold may be activated for the SRB. The different data volume thresholds may be associated with flags or indicators that may be used while triggering and / or activating the MT-SDT (e.g., via paging). In an embodiment, when an SRB is initially configured for MT-SDT, a default data volume threshold may be activated and applicable. In an embodiment, the WTRU may be configured with a default / first data volume threshold that may be aligned with the size of an expected NAS message (e.g., LPP message) carrying positioning information.

[0313] In an embodiment, 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., first) whether the expected positioning information is below a default / first data volume threshold (which may be based, for example, on the type of positioning message (e.g., LPP / LCS message) or message generated and transmitted by the WTRU in the UL). If the expected positioning information is determined to be higher than the first data volume threshold and / or lower than or equal to the second configured data volume threshold, the WTRU may trigger activation of the MT-SDT. Activation of the MT-SDT may be triggered by sending a resume request to the network including an indicator / flag associated with the second data volume threshold (e.g., in the UL-SDT using RA-SDT or CG-SDT resources). The WTRU may receive (e.g., may then receive) a positioning indication if it receives a resume message (e.g., RRC resume in the MT-SDT) indicating activation of the second data volume threshold. The WTRU may continue to receive one or more positioning information messages (e.g., periodic assistance data) if the second data volume threshold (e.g., in this case) remains activated and / or is not deactivated by the network. The data volume threshold (e.g., the data volume threshold described above) may be configured by the LMF or the gNB.

[0314] Examples are provided herein in which the WTRU sends indications / information about the RRC state and / or MO-SDT / MT-SDT configuration to the LMF to support an associated positioning procedure. The WTRU may send information indicative of the WTRU RAN configuration. The information indicative of the WTRU RAN configuration may include at least one of its RRC state, MO-SDT and / or MT-SDT configuration, or a positioning configuration applied in the RRC state. The information indicative of the WTRU RAN configuration may be sent to the LMF to support a location procedure associated with the RRC state / configuration. In an example, the WTRU may send an indication to the LMF when transitioning from CONNECTED to low power operation (e.g., INACTIVE state) so that the WTRU may receive assistance data (e.g., PRS configuration). The assistance data may apply when the WTRU operates in the INACTIVE state. The WTRU may send an indication (e.g., the indications described above) to the LMF via the LPP, RRC, MAC CE, or UCI.

[0315] In an embodiment, the 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 the positioning information based on information sent by the WTRU to the network about 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 balance trade-offs, for example, with respect to achieving high positioning accuracy, high device efficiency (e.g., low power consumption), and / or low latency positioning.

[0316] In an embodiment, the WTRU may receive assistance data. The assistance data may include one or more PRS configurations to be used to make measurements when operating in the INACTIVE / IDLE state. The PRS configurations may be based on instructions sent by the WTRU to the network for the current and / or future RRC state, MT-SDT, and MO-SDT configurations. The WTRU may receive a PRS configuration to be used when the WTRU is operating in a particular RRC state and / or MO-SDT / MT-SDT configuration. The WTRU may use a first PRS configuration when configured with a first combination of MO-SDT and MT-SDT configurations (e.g., with a high data volume threshold / payload size on UL / DL). The WTRU may (e.g., may use) a second PRS configuration when configured with a second combination of MO-SDT and MT-SDT configurations (e.g., with a low data volume threshold / payload size on UL / DL). Use of the first PRS configuration may result in shorter measurement duration and lower latency. Use of the second PRS configuration may result in lower power operation and longer measurement duration / latency.

[0317] In an embodiment, if the WTRU is configured with an SDT for sending data (e.g., positioning information) when in the 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 sending measurement reports when in the INACTIVE state. The parameters associated with the measurement reporting configuration (which may be received, for example, by the WTRU) may include at least one of the type of measurements to be reported (e.g., rich / simplified reporting), the amount of measurements to be reported (e.g., size of each measurement report), or the periodicity of the reports. Whether the reports are simplified or rich may be determined by the number of paths (e.g., additional paths) over which the WTRU reports measurements.

[0318] The WTRU may report (e.g., in a simplified report) PRS measurements associated with a path (e.g., a main path). In rich reporting, the WTRU may report PRS measurements associated with the main path and N additional paths, where N may be configured by the LMF. Parameters for measurement reporting configuration may be received from the LMF based on information sent by the WTRU on a data volume threshold configured for the SDT (e.g., in one or more SRBs / DRBs). The WTRU may be configured to send measurement reports (e.g., simplified measurement reports) in the INACTIVE state, e.g., with reduced granularity, based on knowledge in the LMF of a (lower) data volume threshold configured for the SDT.

[0319] The WTRU may send MT-SDT configuration information for INACTIVE / IDLE mode operation to the LMF, including information about SRB / DRB (e.g., SRB2) configured for MT-SDT and / or DRX configuration. The WTRU may send information (e.g., information described above) to the LMF via the LPP, RRC, MAC CE, or UCI. The configuration information for INACTIVE mode operation may be sent by the WTRU to the LMF upon receiving at least one of an LPP / LCS message, receiving a new / updated MT-SDT / MO-SDT configuration, receiving a new / updated DRX configuration, or if the WTRU RRC state has changed.

[0320] An example of a WTRU receiving an instruction to use an MT-SDT configuration during mobility is provided herein. When the WTRU moves to a cell / gNB (e.g., a new cell / gNB), it may receive an MT-SDT configuration (e.g., a new or updated MT-SDT configuration), and thus the WTRU may continue to receive (any of) DL messages / configurations and perform PRS measurements and / or SRSp transmissions while remaining in an RRC INACTIVE / IDLE state. The WTRU may be configured (e.g., initially configured) with MT-SDT (e.g., in an RRCRelease message) to receive positioning information and / or SRSp configuration (e.g., periodically) from a source cell / TRP. The WTRU may be configured (e.g., with an MT-SDT configuration) by the source cell / TRP with one or more validity conditions including a TA timer, a validity duration, and / or a validity area (e.g., a list of cell IDs). One or more validity conditions may be used by the WTRU to determine if the MT-SDT configuration is valid for use when in the RRC INACTIVE / IDLE state.

[0321] If the WTRU moves to a cell (e.g., a new cell) whose cell ID (e.g., a new cell ID) may be within its coverage area, the WTRU may use (e.g., continue to use) the MT-SDT configuration to receive positioning information and / or configuration over the MT-SDT while in the RRC INACTIVE / IDLE state. In an embodiment, a WTRU that may be configured with semi-persistent SRSp may receive an activation indication (e.g., MAC CE) from a source / first cell to activate SRSp transmission. A WTRU that may be configured with semi-persistent SRSp may (e.g., may receive) a deactivation indication (e.g., MAC CE) to stop SRSp transmission from another / second cell. The activation and / or deactivation indication may be received over the MT-SDT (e.g., in this case, possibly due to the MT-SDT being configured to be valid across different cells).

[0322] If one or more validity conditions expire, the WTRU may move to a new / target cell / TRP, which may be outside the validity area, and the WTRU may send an indication to the network (e.g., in an initial access message or an RRC Resume request via SDT). The WTRU may (e.g., may send) an indication in the ID with a cause value indicating expiration / release of the previous MT-SDT configuration and / or a request for an MT-SDT configuration (e.g., a new MT-SDT configuration). When fetching the WTRU context from the source cell / TRP, the target cell / TRP may determine whether the WTRU may be assigned / activated with a new MT-SDT configuration or whether the WTRU may continue to use the previous MT-SDT configuration (e.g., based on an identifier and / or a request sent by the WTRU, as the case may be).

[0323] In response to the indication sent by the WTRU due to expiration of the previous MT-SDT configuration, the WTRU may receive from the target cell / TRP one or more of an RRCResume message (e.g., in Msg B or Msg 4) indicating to use the new MT-SDT configuration, an RRCRelease message (e.g., in Msg B or Msg 4) indicating to release the previous MT-SDT configuration and / or to use the new MT-SDT configuration, or an RRCRelease message indicating to continue using the previous MT-SDT configuration.

[0324] The RRCResume and / or RRCRelease messages may include parameters associated with a new MT-SDT configuration (e.g., RA-SDT and / or CG-SDT resources) or may include an activation instruction for activating a pre-configured MT-SDT configuration (e.g., an ID of the configuration).

[0325] An example of a WTRU receiving assistance data / configuration for positioning over MT-SDT during mobility is provided herein. If the WTRU moves to a cell / TRP (e.g., a new cell / TRP) while continuing to operate in an RRC INACTIVE / IDLE state, it may receive the assistance data / configuration, which may include one or more positioning configurations (e.g., PRS / SRSp configurations) over MT-SDT. If the WTRU triggers an LCS / LPP procedure for positioning while in the coverage of the source cell / TRP, it may receive (e.g., initially receive) the assistance data over either broadcast, dedicated RRC signaling, or an LPP message. The WTRU may receive the assistance data over dedicated signaling while in the CONNECTED state (e.g., in this case) when it transitions to low power operation (e.g., RRC INACTIVE / IDLE state) (e.g., in an RRCRelease message) or when it is in low power operation (e.g., INACTIVE / IDLE state) (e.g., over MT-SDT).

[0326] 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 area) that may be used to determine whether the assistance data (e.g., PRS / SRSp configuration) is valid for use when in RRC INACTIVE / IDLE state. In an embodiment, 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 be valid / invalid (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.

[0327] The WTRU may receive configurations / rules for determining whether to send a request for assistance data (e.g., new assistance data) in dedicated NAS / RRC signaling, UL SDT, or obtain assistance data (e.g., new assistance data) via broadcast RRC signaling (e.g., SIB) (e.g., including, e.g., possibly, on-demand SIB). In an embodiment, the configurations / rules may indicate a first set including one or more cell / TRP IDs from which the WTRU may be allowed to send a request for (e.g., new) assistance data (e.g., PRS / SRSp configurations). The configurations / rules may (e.g., may indicate) a second set including one or more cell / TRP IDs from which the WTRU may receive assistance data (e.g., new assistance data) within the MT-SDT, which may at least partially overlap with the first set.

[0328] If the conditions / rules associated with sending the request are met (e.g., the new cell / TRP ID is outside the coverage area), a WTRU in RRC INACTIVE state may send a request message (e.g., an RRCResumeRequest message over an SDT) for assistance data (e.g., new assistance data) for one or more (e.g., new) PRS and / or SRSp configurations. The WTRU may include an identifier (e.g., I-RNTI) and / or previous assistance data (e.g., PRS / SRSp configuration ID) associated with the WTRU in the indication. The cell / TRP (e.g., new cell / TRP) may fetch a WTRU context from the source cell / TRP based on the WTRU ID and the request for assistance data (e.g., new assistance data) received from the WTRU. The WTRU may include a cause value in the indication indicating expiration and / or release of previous assistance data / configuration to request new assistance data. In response to the request, the WTRU may receive at least one of new assistance data (e.g., via the MT-SDT), an activation indication for pre-configured assistance data (e.g., for a pre-configured PRS / SRSp configuration), or an indication to continue using the previous assistance data. The WTRU may receive an RRCResume message, an RRCRelease message (e.g., in Msg B or Msg 4), or a response indication in the MT-SDT.

[0329] Examples associated with supporting DL- and UL-based LPHAP are provided herein. When in low power operation (e.g., INACTIVE / IDLE state), the WTRU may be configured to perform DL- and UL-based LPHAP (e.g., using a multi-RTT positioning technique) based on DL-PRS measurements and / or UL-SRSp transmissions in one or more RTT cycles. The DL- and UL-based positioning may include a first phase and a second phase. The first and second phases may include DL-PRS reception and / or measurement at the WTRU and UL-SRSp transmission from the WTRU to the TRP. In the WTRU-assisted DL- and UL-based positioning, the WTRU may report DL-PRS measurements (e.g., RSRP, PRS time-of-arrival (ToA), RSTD measurements) and / or PRS reception and SRSp transmission timing difference measurements (e.g., WTRU Rx-Tx) to the network. For multi-RTT positioning, the location 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 techniques (e.g., any of them) associated with DL and UL based LPHAP (e.g., as described herein). Such techniques may include one or more of mitigating positioning errors in DL and UL based positioning, applying condition dependent configurations / resources, aligning DL-PRS transmissions with UL-SRSp reception, applying in-band resources for DL-PRS and UL-SRSp transmissions, or applying inter-band resources for DL-PRS and UL-SRSp transmissions.

[0330] To mitigate positioning errors in DL and UL based positioning, the WTRU may switch from an estimation / prediction mode to a measurement mode for DL ​​based positioning in the first phase (e.g., DL-PRS measurement) if it detects a positioning error (e.g., any positioning error) when performing UL based positioning in the second phase (e.g., UL-SRSp transmission). In an embodiment, the WTRU may switch the UL based positioning between the estimation / prediction mode and the measurement mode in the first phase if it detects a positioning error when performing DL based positioning in the second phase. The WTRU may be configured by the network with one or more thresholds. The one or more thresholds may be associated with a positioning error for determining 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 embodiment, if the WTRU performs an RSRP measurement of the DL-PRS received in the first phase and / or an RSRP measurement below a threshold, the WTRU may perform an SRSp transmission in the second phase using a selected SRSp configuration (e.g., high Tx power, high repetition, high periodicity) that may result in improved measurement accuracy. Such a scenario may occur when the WTRU is located in one or more areas with limited coverage and has poor radio link quality. If the RSRP measurement of the PRS is above a threshold, the WTRU may transmit an SRSp using an SRSp configuration (e.g., low Tx power, low repetition, low periodicity) that may result in improved power savings at the WTRU.

[0331] To apply condition-dependent configurations / resources, the WTRU may be pre-configured with PRS / SRSp resources / configurations. The PRS / SRSp resources / configurations may depend on one or more cells / zones / areas in which the WTRU will be located or is expected to move. The WTRU may use certain PRS / SRSp resources for UL and DL positioning if (e.g., in this case) it is located in a cell / area associated with the PRS / SRSp resources. The WTRU may be pre-configured with conditions and / or restrictions for using the PRS / SRSp resources. In an embodiment, the WTRU may be configured with conditions associated with radio link quality, including one or more of RSRP, path loss threshold (e.g., RSRP of PRS, SSB), or TA, to determine if the WTRU may use an SRSp configuration (e.g., after performing PRS measurements). The WTRU may use a limited set of SRSp resources if (e.g., in this case) the RSRP of the PRS measurement is below a threshold.

[0332] 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 the 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 transmissions may be performed by the WTRU over short and / or aligned time windows / DRX cycles. When implementing such aligned PRS reception and / or SRSp transmission, the WTRU may perform one or more of: determining aligned time windows / DRX cycles (e.g., based on PRS and / or SRSp configuration information); determining a PRS and / or SRSp configuration to apply based on a preconfigured time window / DRX cycle; sending an instruction to the network requesting to configure and / or trigger aligned time windows / DRX cycles; or receiving an instruction from the network indicating the configuration and / or triggering of aligned time windows / DRX cycles for DL ​​and UL positioning.

[0333] To apply in-band resources for DL-PRS and UL-SRSp transmissions, the WTRU may use DL-PRS resources and / or UL-SRSp resources. DL-PRS resources and / or UL-SRSp resources may be associated with similar bands and / or resource pools during transmission and / or reception in the INACTIVE / IDLE state. The use of similar bands within the same band / BWP may be intended to minimize the amount of bandwidth that the WTRU may be allowed to use while in the INACTIVE / IDLE state and / or to minimize power consumption at 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 the PRS and / or SRSp. Such use may improve power savings at the WTRU by avoiding re-tuning to a different center frequency when performing SRSp transmission after performing PRS reception, or vice versa.

[0334] When applying inter-band resources for DL-PRS and UL-SRSp transmissions, the WTRU may be configured with one or more FR2 bands for PRS and SRSp configurations / resources for performing DL and UL positioning. If the PRS measurements made by the WTRU indicate poor link quality or high path loss (e.g., the RSRP of the PRS is below a threshold), the WTRU may switch to using an SRSp configuration and / or resources in the FR1 band to mitigate link-related issues (e.g., in this case). When switching to an SRSp configuration in the FR1 band, the WTRU may use lower Tx power during SRSp transmission. Such switching between the FR2 and FR1 bands may be configured and / or applied by the WTRU when in a coverage / power-limited scenario and / or operating in an INACTIVE / IDLE state.

[0335] The WTRU may be configured to perform DL and UL positioning when in low power operation (e.g., INACTIVE / IDLE state) based on a triggering event. In an embodiment, 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 when operating in INACTIVE / IDLE state based on detection of a preconfigured positioning triggering event. Such positioning triggering events may include one or more of a time event (e.g., timer expiration, periodic event), an area event (e.g., an event triggered when entering a new area / cell), or a mobility event (e.g., speed, orbit change).

[0336] If the WTRU is in the INACTIVE state and / or if MO-SDT is supported (e.g., only if MO-SDT is supported), the WTRU may trigger an SDT procedure at least twice for one or more of: to trigger DL and UL based positioning, or to send an initial request message to the network (e.g., LMF) based on detection of one or more events for sending a measurement report to the network (e.g., after performing PRS measurements (e.g., PRS time of arrival, RSRP) and SRSp transmission). If the WTRU is in the IDLE state, the WTRU may perform a RACH to move to the CONNECTED state, or may send UL data using a UL resource grant (e.g., received in Msg 2) or preconfigured UL resource (PUR) (e.g., at each time instance when the WTRU wishes to send (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.

[0337] When operating in the INACTIVE / IDLE state, the WTRU may send an initial request message (e.g., to report a positioning trigger event) to the network (e.g., gNB) in an initial access message (e.g., in Msg 1, Msg 3, Msg A, PRACH preamble). In an embodiment, the initial access message may include an instruction to forward a request to the LMF to initiate a positioning procedure (e.g., to trigger DL and UL based positioning). In an embodiment, the initial access message may allow the WTRU to send (e.g., quickly send) a request message / instruction (e.g., any request message / instruction) to the network and / or eliminate the overhead of sending / receiving (e.g., additional) signaling (e.g., event report ACK / NACK feedback) or the latency to transition to the CONNECTED state.

[0338] When sending an initial request message (e.g., via an initial access message and / or SDT), the WTRU may perform one or more of the following if in INACTIVE / IDLE state: receive assistance data, use pre-configured assistance data, receive one or more SRSp configurations / resources for UL-SRSp transmission, or receive instructions to trigger PRS measurements and / or SRSp transmission.

[0339] 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 if the WTRU sends an indication in an initial request message requesting assistance data. Such assistance data may be received if preconfigured assistance data (e.g., any of the preconfigured assistance data) in the WTRU is no longer valid (e.g., due to timer expiration, validity area expiration).

[0340] To use the preconfigured assistance data, the preconfigured assistance data may include (e.g., any of) PRS configurations and / or resources for DL-PRS measurements. Such preconfigured assistance data may be used by the WTRU if it is determined by the WTRU to be valid for use during PRS measurements. Such preconfigured assistance data may be used by the WTRU if it receives an indication from the network. The indication from the network may indicate using one or more preconfigured PRS configurations (e.g., configuration IDs).

[0341] An instruction to use one or more SRSp configurations / resources for UL-SRSp transmission (e.g., an ID of an SRSp configuration) or a pre-configured SRSp configuration may be received by the WTRU via an initial access message, an LPP message, an RRC message (e.g., using MT-SDT), a MAC CE, or a DCI.

[0342] To receive an instruction to trigger PRS measurements and / or SRSp transmission, such an instruction may be received by the WTRU via an initial access message (e.g., Msg 2, Msg 4, MsgB) or MT-SDT. Such an instruction may include one or more of an LPP message (e.g., request for location information, 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 aperiodic, semi-persistent, and / or periodic SRSp, the WTRU may receive the trigger instruction via a DCI, a MAC CE, an RRC, or a paging message (e.g., indicating the type (e.g., ID) of the SRSp).

[0343] The PRS / SRSp configuration and / or indication / trigger message may be received by the WTRU within a paging message or as part of a paging message. In an embodiment, the WTRU may receive an indication of a WTRU ID (e.g., P-RNTI) and / or an indication / trigger message for SRSp transmission in a PDCCH (e.g., within a paging message or during a paging occasion). The WTRU may monitor the PDCCH and / or PDSCH to receive the SRSp / PRS configuration and / or indication / trigger message within the paging message and / or within DL reception (e.g., a subsequent DL reception). In an embodiment, the DL reception may include the MT-SDT. In an embodiment, the WTRU may receive the PRS / SRSp configuration and / or indication / trigger message within a wake-up signal (WUS).

[0344] If receiving a PRS / SRSp configuration and / or an 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 receipt of the PRS and transmission of the SRSp (e.g., WTRU Rx-Tx difference). If performing PRS measurements and / or SRSp transmission, the WTRU may transmit measurement reports including PRS measurements (e.g., arrival time, RSRP), WTRU Rx-Tx difference measurements, etc. To transmit a measurement report when in an INACTIVE / IDLE state, the WTRU may send the report in an initial access message (e.g., Msg A, Msg 3) or trigger an SDT procedure. In an embodiment, the WTRU may send the report in Msg 5. In an embodiment, the WTRU may determine to send the SRSp and measurement reports in the same message (e.g., Msg 3, Msg 5, Msg A).

[0345] The WTRU may determine to perform round trip time (RTT) based positioning. The WTRU may be pre-configured to perform RTT based positioning if the SSB RSRP is above a pre-configured threshold. The WTRU may measure the arrival time of the SSB and send the corresponding Msg A preamble and measurement report in message A. The measurement report may include the WTRU Rx-Tx difference, or the RSRP. The WTRU Rx-Tx difference may be the difference between the arrival time during the SSB (e.g., in this case) and the transmission time of the corresponding preamble or SRSp.

[0346] Although the above-described features and elements are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments, or may be used in various combinations with or without the other features and elements.

[0347] It will be appreciated that while the implementations described herein may take into account 3GPP-specific protocols, the implementations described herein are not limited to this scenario and may be applicable to other wireless systems. For example, while the solutions described herein take into account LTE, LTE-A, new radio (NR), or 5G-specific protocols, it will be appreciated that the solutions described herein are not limited to this scenario and may be applicable to other wireless systems.

[0348] The above-described processes may be implemented in a computer program, software, and / or firmware embodied 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 (transmitted over wired and / or wireless connections) 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, internal hard disks and removable disks, magneto-optical media, and / or optical media such as Compact Disc (CD)-ROM disks, and / or Digital Versatile Disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, a terminal, a base station, a Radio Network Controller (RNC), and / or any host computer.

Claims

1. 1. A wireless transmit / receive unit (WTRU), comprising: a processor, the processor comprising: transmitting a sounding reference signal for positioning (SRSp) configuration request, wherein the SRSp configuration request is transmitted when the WTRU is in an inactive state and the SRSp configuration request is transmitted 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; 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; the first SRSp configuration identifying a first set of resources associated with an SRSp transmission, and the second SRSp configuration identifying a second set of resources associated with the SRSp transmission. And, selecting the first SRSp configuration or the second SRSp configuration, the selection being based on whether the WTRU's location is within the first positioning area associated with the first SRSp configuration or within the second positioning area associated with the second SRSp configuration; transmitting an SRSp using the first SRSp configuration or the second SRSp configuration; A WTRU configured to:

2. 2. The WTRU of claim 1, wherein the first set of cells includes a first set of cell IDs and the second set of cells includes a second set of cell IDs, 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 processor: determining whether a cell ID is in the first set of cell IDs or the second set of cell IDs; further configured to:

3. The WTRU of claim 2, wherein selecting the first SRSp configuration or the second SRSp configuration is further based on determining whether the cell ID is within the first set of cell IDs or the second set of cell IDs.

4. the first SRSp configuration is selected if the cell ID is detected to be within the first set of cell IDs; The WTRU of claim 3 , wherein the second SRSp configuration is selected if the cell ID is detected to be within the second set of cell IDs.

5. The processor: deactivating the first SRSp configuration or the second SRSp configuration that was not selected; The WTRU of claim 1 , further configured to:

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

7. 1. A method associated with a wireless transmit / receive unit (WTRU), the method comprising: transmitting a sounding reference signal for positioning (SRSp) configuration request, wherein the SRSp configuration request is transmitted when the WTRU is in an inactive state and the SRSp configuration request is transmitted 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; 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; the first SRSp configuration E 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. And, selecting the first SRSp configuration or the second SRSp configuration, the selection being based on whether the WTRU's location is within the first positioning area associated with the first SRSp configuration or within the second positioning area associated with the second SRSp configuration; transmitting an SRSp using the first SRSp configuration or the second SRSp configuration; A method comprising:

8. 8. The method of claim 7, wherein the first set of cells includes a first set of cell IDs and the second set of cells includes a second set of cell IDs, 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. 9. The method of claim 8, further comprising: determining whether a cell ID is within the first set of cell IDs or the second set of cell IDs; and selecting the first SRSp configuration or the second SRSp configuration is further based on determining whether the cell ID is within the first set of cell IDs or the second set of cell IDs.

10. the first SRSp configuration is selected if the cell ID is detected to be within the first set of cell IDs; 10. The method of claim 9, wherein the second SRSp configuration is selected if the cell ID is detected to be within the second set of cell IDs.

11. The method of claim 7 , further comprising deactivating the first SRSp configuration or the second SRSp configuration that was not selected.

12. The method of claim 7 , wherein transmitting the SRSp is performed during the inactive state.

Images