Anchor user equipment selection for positioning

Abstract

Anchor UEs may be mobile or have low transmission power, affecting the accuracy of target UE positioning estimates based on measurements of the PRS associated with the anchor UE. One or more candidate anchor UEs can be selected or excluded for positioning based on measurement quality metrics of the candidate anchor UE's positioning measurements, the action status of the candidate anchor UE, or one or more GDOPs associated with the candidate anchor UE. The action status of the candidate anchor UE can be exported from the reported positioning of the candidate anchor UE or obtained from the candidate anchor UE. UEs selected as anchor UEs are used to locate target UEs, and UEs that are not selected as anchor UEs are excluded from the target UE positioning process.

Description

Technical Field

[0001] This patent application claims priority and benefit to Greek patent application No. 20210100220 entitled "ANCHOR USER EQUIPMENT SELECTION FOR POSITIONING", filed on March 31, 2021, which has been assigned to the assignee of this application and is expressly incorporated herein by reference in its entirety.

[0002] The subject matter disclosed herein relates to locating a user device using received positioning reference signals, and more specifically to selecting an anchor user device to be used for positioning. Prior Technology

[0003] The location of user equipment (UE), such as cellular phones, can be useful or essential for many applications, including emergency dialing, navigation, direction finding, asset tracking, and internet services. The UE's location can be estimated based on information collected from various systems. For example, in cellular networks implemented using 4G (also known as fourth-generation) Long Term Evolution (LTE) radio access or 5G (also known as fifth-generation) New Radio (NR), the base station can transmit downlink reference signals for positioning, or the UE can transmit sidelink reference signals for positioning, such as a Position Reference Signal (PRS). Supporting data is sent to the UE to aid in acquiring and measuring signals, and in some implementations, to calculate location estimates based on these measurements. The UE can acquire PRS transmitted from different base stations or UEs and perform positioning measurements, such as Reference Signal Time Difference (RSTD) measurement, Reference Signal Received Power (RSRP) measurement, and Receive-to-Transmit (RX-TX) time difference measurement. These measurements can be used in various positioning methods, such as Time Difference of Arrival (TDOA), Angle of Departure (AoD), and Multi-cell Round-Trip Time (RTT). The UE can use various positioning methods to calculate an estimate of its own location, or it can send positioning measurements to a network entity (e.g., a location server) that can calculate the UE's location based on the positioning measurements. Improvements in positioning accuracy are expected. Summary of the Invention

[0004] Anchor user equipment (UE) serving as a transmit / receive point (TRP) for transmitting and / or receiving Positioning Reference Signals (PRS) may be mobile or have lower transmission power compared to other UEs, potentially affecting the accuracy of the positioning estimate of the target UE based on PRS measurements associated with the anchor UE. One or more candidate anchor UEs may be excluded from positioning one or more other UEs based on one or more of the following: measurement quality metrics of the candidate anchor UE's positioning measurements, the operational status of the candidate anchor UE, or the geometric dilution of precision (GDOP) associated with the candidate anchor UE. Measurement quality metrics may be based on the Reference Signal Time Difference (RSTD) or the accuracy of the satellite system or other sensors used to determine the positioning of the candidate anchor UE. The operational status of the candidate anchor UE can be derived from the candidate anchor UE's reported positioning or obtained from the candidate anchor UE. The candidate anchor UE selected as the anchor UE is used to position the target UE. In some embodiments where one or more candidate anchor UEs are selected from a group of candidate anchor UEs, a candidate anchor UE may be excluded from the group when a downselection is performed on the group of candidate anchor UEs used for the target UE. In this way, the candidate anchor UE is excluded from use as an anchor UE for locating the target UE.

[0005] In one embodiment, a method for selecting an anchor UE for locating a target UE in a wireless network includes the steps of: obtaining a measurement quality metric of one or more positioning measurements of the candidate anchor UE and each of the positioning measurements from one or more candidate anchor UEs among a plurality of candidate anchor UEs; and selecting a plurality of candidate anchor UEs for locating the target UE based on the one or more measurement quality metrics from the one or more candidate anchor UEs.

[0006] In one embodiment, an apparatus configured to select an anchor UE for locating a target UE in a wireless network includes: at least one transceiver, at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. The at least one processor is configured to cause the apparatus to: obtain, via the at least one transceiver and from one or more candidate anchor UEs among a plurality of candidate anchor UEs, one or more positioning measurements of the candidate anchor UEs and a measurement quality metric of each of the positioning measurements; and select, via the at least one processor, a plurality of candidate anchor UEs for locating the target UE based on the one or more measurement quality metrics from the one or more candidate anchor UEs.

[0007] In one embodiment, a non-transitory computer-readable medium includes instructions that, when executed by at least one processor of a device configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, cause the device to: obtain, via at least one transceiver and from one or more candidate anchor UEs among a plurality of candidate anchor UEs, a measurement quality metric of one or more positioning measurements of the candidate anchor UEs and each of the positioning measurements; and select, via at least one processor, a plurality of candidate anchor UEs for locating the target UE based on the one or more measurement quality metrics from the candidate anchor UEs.

[0008] In one embodiment, an apparatus configured to select an anchor UE for locating a target UE in a wireless network includes: a component for obtaining one or more positioning measurements of the candidate anchor UE and a measurement quality metric of each of the positioning measurements from one or more candidate anchor UEs among a plurality of candidate anchor UEs; and a component for selecting a plurality of candidate anchor UEs for locating the target UE based on one or more measurement quality metrics from one or more candidate anchor UEs.

[0009] In one embodiment, a method for selecting an anchor UE for locating a target UE in a wireless network includes the steps of: determining the action state of one or more candidate anchor UEs from a plurality of candidate anchor UEs; and selecting the plurality of candidate anchor UEs based on one or more action states for locating the target UE.

[0010] In one embodiment, an apparatus configured to select an anchor UE for locating a target UE in a wireless network includes: at least one transceiver, at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. The at least one processor is configured to cause the apparatus to: determine the operational state of a candidate anchor UE via one or more of the at least one transceiver or at least one processor and for one or more candidate anchor UEs among a plurality of candidate anchor UEs; and select one or more candidate anchor UEs via the at least one processor based on the one or more operational states for locating the target UE.

[0011] In one embodiment, a non-transitory computer-readable medium includes instructions that, when executed by at least one processor of a device configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, cause the device to: determine the operational state of a candidate anchor UE via one or more of at least one transceiver or at least one processor and for one or more of a plurality of candidate anchor UEs; and select one or more of the candidate anchor UEs via at least one processor based on the one or more operational states for locating the target UE.

[0012] In one embodiment, an apparatus configured to select an anchor UE for locating a target user equipment (UE) in a wireless network includes: a component for determining the operational state of one or more candidate anchor UEs among a plurality of candidate anchor UEs; and a component for selecting one or more candidate anchor UEs based on the operational state for locating the target UE.

[0013] In one embodiment, a method for selecting an anchor UE for locating a target UE in a wireless network includes the steps of: selecting one or more anchor UEs from a plurality of candidate anchor UEs for locating the target UE, wherein the selection is based on a plurality of GDOPs, wherein each GDOP is determined by the target UE for different combinations of candidate anchor UEs from the plurality of candidate anchor UEs.

[0014] In one embodiment, a device configured to select an anchor UE for locating a target UE in a wireless network includes: at least one transceiver, at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. The at least one processor is configured to cause the device to select one or more anchor UEs from a plurality of candidate anchor UEs for locating the target UE via one or more of the at least one transceiver or the at least one processor, wherein the selection is based on a plurality of GDOPs, where each GDOP is determined by the target UE for different combinations of candidate anchor UEs from the plurality of candidate anchor UEs.

[0015] In one embodiment, a non-transitory computer-readable medium includes instructions that, when executed by at least one processor of a device configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, cause the device to select one or more anchor UEs from a plurality of candidate anchor UEs for locating the target UE via one or more of at least one transceiver or at least one processor, wherein the selection is based on a plurality of GDOPs, wherein each GDOP is determined by the target UE for different combinations of candidate anchor UEs from the plurality of candidate anchor UEs.

[0016] In one embodiment, an apparatus configured to select an anchor UE for locating a target user equipment (UE) in a wireless network includes means for selecting one or more anchor UEs from a plurality of candidate anchor UEs for locating the target UE, wherein the selection is based on a plurality of GDOPs, wherein each GDOP is determined by the target UE for different combinations of candidate anchor UEs from the plurality of candidate anchor UEs.

[0017] Based on the accompanying drawings and embodiments, other objects and advantages associated with the various embodiments disclosed herein will be apparent to those skilled in the art. Simple Explanation of the Diagram

[0018] The accompanying drawings are provided to help describe the various forms of this case, and the drawings are provided only to illustrate the forms and not to limit them.

[0019] Figure 1 illustrates exemplary wireless communication systems according to various aspects of this case.

[0020] Figure 2 illustrates a block diagram of the design of a base station and a user equipment (UE), which can be one of the base stations and one of the UEs in Figure 1.

[0021] Figure 3 illustrates a UE that supports location services in a wireless network.

[0022] Figure 4 illustrates a base station that can support location services in a wireless network.

[0023] Figure 5 illustrates a server that can support location services in a wireless network.

[0024] Figure 6 is a diagram illustrating an exemplary technique for determining the location of a mobile device using information obtained from a plurality of base stations.

[0025] Figure 7 illustrates a flowchart of an exemplary method for selecting an anchor UE for locating a target UE in a wireless network.

[0026] Figure 8 illustrates a flowchart of an exemplary method for selecting an anchor UE for locating a target UE in a wireless network.

[0027] Figure 9A is a diagram illustrating the first positioning uncertainty of a UE associated with the two Transmit-Receive Points (TRPs) used for positioning.

[0028] Figure 9B is a diagram illustrating the second positioning uncertainty of the UE associated with the two TRPs used for positioning.

[0029] Figure 10 illustrates a flowchart of an exemplary method for selecting an anchor UE for locating a target UE in a wireless network.

[0030] Figure 11 illustrates a flowchart of an exemplary method for selecting an anchor UE for locating a target UE in a wireless network. Implementation

[0031] Various embodiments of this invention are provided in the following description and related figures, which are provided for illustrative purposes. Alternative embodiments may be designed without departing from the scope of this invention. Furthermore, well-known elements of this invention will not be described in detail or will be omitted to avoid obscuring the relevant details of this invention.

[0032] The terms "exemplary" and / or "example" are used herein to mean "serving as an example, instance, or illustration." Any mode described herein as "exemplary" and / or "example" is not necessarily to be construed as superior or advantageous to other modes. Similarly, the term "modes of the case" does not require that all modes of the case include the features, advantages, or modes of operation discussed.

[0033] Those familiar with this technology will understand that any of a variety of different technologies and processes can be used to represent the information and signals described below. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout this specification can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof, depending in part on the specific application, in part on the required design, and in part on the appropriate technology.

[0034] Furthermore, many states are described based on the sequence of actions to be performed by elements of, for example, a computing device. It should be understood that the various actions described herein can be performed by specific circuitry (e.g., an application-specific integrated circuit (ASIC)), program instructions executed by one or more processors, or a combination of both. Additionally, the sequence (one or more) of actions described herein can be considered entirely embodied in any form of non-transitory computer-readable storage medium storing a corresponding computer instruction set, which, upon execution, will cause or instruct the associated processor of the device to perform the functions described herein. Therefore, the various states of this application can be embodied in many different forms, all of which are considered to be within the scope of the claimed object. Furthermore, for each state described herein, any corresponding form of such state can be described, for example, as "logic" "configured" to perform the actions.

[0035] As used herein, unless otherwise indicated, the terms “User Equipment” (UE) and “Base Station” are not intended to be specific or otherwise limited to any particular Radio Access Technology (RAT). Generally, a UE can be any wireless communication device (e.g., mobile phone, router, tablet, laptop, tracking device, wearable device (e.g., smartwatch, glasses, augmented reality (AR) / virtual reality (VR) headset, etc.), vehicle (e.g., car, motorcycle, bicycle, etc.), Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communication network. A UE can be mobile or can (e.g., at certain times) be stationary and can communicate with a Radio Access Network (RAN). As used herein, the term “UE” can be interchangeably referred to as “Access Terminal” or “AT,” “Client Equipment,” “Wireless Equipment,” “User Equipment,” “User Terminal,” “User Station,” “User Terminal,” or “UT,” “Mobile Terminal,” “Mobile Station,” “Mobile Device,” or variations thereof. Typically, a UE can communicate with the core network via the RAN, and through the core network, the UE can connect to external networks such as the Internet and to other UEs. Of course, other mechanisms for connecting to the core network and / or the Internet are also possible for the UE, such as via wired access networks, wireless local area network (WLAN) networks (e.g., based on the IEEE 802.11 standard set), etc.

[0036] A base station can operate based on the network in which it is deployed, according to one of several RATs for communicating with the UE, and can be alternatively referred to as an Access Point (AP), Network Node, NodeB, Evolved NodeB (eNB), New Radio (NR) NodeB (also known as gNodeB or gNB), etc. Furthermore, in some systems, the base station may purely provide edge node signaling functions, while in others, it may provide additional control and / or network management functions. The communication link through which the UE can send signals to the base station is called an uplink (UL) channel or reverse link channel (e.g., reverse traffic channel, reverse control channel, access channel, etc.). The communication link through which the base station can send signals to the UE is called a downlink (DL) or forward link channel (e.g., paging channel, control channel, broadcast channel, forward traffic channel, etc.). The communication link through which the UE can send signals to or from each other is called a side link (SL). As used herein, the term Traffic Channel (TCH) can refer to either a UL / reverse or DL / forward traffic channel.

[0037] The term "base station" can refer to a single physical transmit / receive point (TRP) or multiple physical TRPs that may or may not be co-located. For example, when the term "base station" refers to a single physical TRP, the physical TRP may be the antenna of the base station corresponding to a cell of the base station. When the term "base station" refers to multiple co-located physical TRPs, the physical TRPs may be an array of antennas of the base station (e.g., as in a multiple-input multiple-output (MIMO) system, or where the base station employs beamforming). When the term "base station" refers to multiple non-co-located physical TRPs, the physical TRPs may be a distributed antenna system (DAS) (a network of spatially separated antennas connected via a transmission medium to a shared source) or a remote radio head unit (RRH) (a remote base station connected to a serving base station). In some implementations, the TRP may be a UE.

[0038] To support UE positioning, two main categories of positioning solutions have been defined: control plane-based and user plane-based. Referring to control plane (CP) positioning, signaling related to positioning and positioning support can be carried via existing network (and UE) interfaces and using existing protocols dedicated to signal transmission. Referring to user plane (UP) positioning, signaling related to positioning and positioning support can be carried using protocols such as Internet Protocol (IP), Transmission Control Protocol (TCP), and User Packet Protocol (UDP) as part of other data.

[0039] The 3rd Generation Partnership Project (3GPP) has defined control plane positioning solutions for UEs using radio access based on the New Radio (NR) of Global System for Mobile Communications (GSM) (2G), Universal Mobile Telecommunications System (UMTS) (3G), LTE (4G), and 5G (5G). These solutions are defined in 3GPP Technical Specifications (TS) 23.271 and 23.273 (General Parts), 43.059 (GSM Access), 25.305 (UMTS Access), 36.305 (LTE Access), and 38.305 (NR Access). For UP positioning, 3GPP Release 16 of the NR standard defines multi-cell round-trip time (RTT), DL departure angle (AOD), and UL arrival angle (AOA), as well as zenith angle and azimuth angle. Release 16 also defines UE-based positioning associated with DL-TDOA and DL-AOD, DL-Positioning Reference Signal (PRS) (DL-PRS), and Detection Reference Signal (SRS) for positioning. Version 16 also defines beam-specific (PRS) operation for millimeter waves and broadcasting of auxiliary data for positioning. Version 17 of the 3GPP standard for NR can define UE-initiated DL-PRS single-request transmission, network-initiated DL-PRS on-demand transmission, Radio Resource Control (RRC) inactive DL-only, UL-only, or DL+UL-based positioning, Access Point (AP) DL-PRS transmission, and / or DL-PRS aggregation on multiple frequencies. The Open Action Alliance (OMA) has similarly defined an UP positioning solution called Secure User Plane Location Determination (SUPL), which can be used to locate UEs accessing any of the multiple radio interfaces supporting IP packet access, such as General Packet Radio Service (GPRS) using GSM, GPRS using UMTS, or IP access using LTE or NR.

[0040] Both CP and UP-based positioning (also known as location determination) solutions can employ a location server to support the positioning (location determination) of the UE. The location server can be part of or accessible from the UE's serving network or home network, or it can be accessed simply via the Internet or local network. If positioning of the UE is required, the location server can initiate a communication period with the UE (e.g., a location determination communication period or a SUPL communication period) and coordinate the determination of the UE's estimated location through location measurements. During the location determination communication period, the location server can request the UE's positioning capabilities (or the UE can provide such capabilities without request), can provide auxiliary data to the UE (e.g., if requested by the UE or without request), and can request location estimates or positioning measurements from the UE for use in various positioning technologies, such as Global Navigation Satellite System (GNSS), Time Difference of Arrival (TDOA), Angle of Departure (AoD), Round Trip Time (RTT), or Multi-RTT, and / or Enhanced Cellular ID (ECID) positioning methods. The UE can use auxiliary data to acquire and measure GNSS and / or PRS signals (e.g., by providing expected characteristics of such signals, such as frequency, expected time of arrival, signal decoding, and signal Doppler).

[0041] In UE-based operating modes, auxiliary data can also be used by the UE to help determine the position estimate from the obtained position measurements (e.g., in the case of GNSS positioning, auxiliary data provides satellite almanac data, or in the case of ground positioning using TDOA, AoD, Multi-RTT, etc., auxiliary data provides base station location and other base station characteristics, such as PRS timing).

[0042] In UE-assisted operation mode, the UE can return position measurements to the position server, which can determine the UE's estimated position based on these measurements and possibly other known or configured data (such as satellite almanac data used for GNSS position determination, or base station characteristics, including base station location and possible PRS timing, when using ground positioning such as TDOA, AoD, Multi-RTT, etc.).

[0043] In another standalone operating mode, the UE can perform position-related measurements without any positioning assistance data from the location server, and can further calculate position or position changes without any positioning assistance data from the location server. Positioning methods that can be used in standalone mode include GPS or other types of GNSS (e.g., if the UE obtains satellite orbit data from data broadcast by the GPS or other GNSS satellites themselves) and sensors.

[0044] In the case of 3GPP CP location determination, the location server can be an Enhanced Serving Mobile Location Determination Center (E-SMLC) for LTE access, a Standalone SMLC (SAS) for UMTS access, a Serving Mobile Location Determination Center (SMLC) for GSM access, or a Location Management Function (LMF) for 5G NR access. In the case of OMA SUPL location determination, the location server can be a SUPL Location Determination Platform (SLP), which can act as any of the following: (i) a Home SLP (H-SLP) if it is in or associated with the UE's home network, or if it provides a permanent subscription to location services for the UE; (ii) an Exploratory SLP (D-SLP) if it is in or associated with another (non-home) network, or if it is not associated with any network; (iii) an Emergency SLP (E-SLP) if it supports location determination for emergency calls initiated by the UE; or (iv) a Visiting SLP (V-SLP) if it is in or associated with the serving network or the UE's current local area.

[0045] During location determination communication, the location server and UE can exchange messages defined according to some positioning protocols to coordinate the determination of the estimated location. Possible positioning protocols may include, for example, the LTE Positioning Protocol (LPP) defined by 3GPP in 3GPP TS 36.355 and the LPP Extensions (LPPe) protocol defined by OMA in OMA TSs OMA-TS-LPPe-V1_0, OMA-TS-LPPe-V1_1, and OMA-TS-LPPe-V2_0. LPP and LPPe protocols can be used in combination, where an LPP message contains an embedded LPPe message. The combined LPP and LPPe protocol can be referred to as LPP / LPPe. LPP and LPP / LPPe can be used to help support 3GPP control plane solutions for LTE or NR access, in which case LPP or LPP / LPPe messages are exchanged between the UE and E-SMLC or between the UE and LMF. LPP or LPPe messages can be exchanged between the UE and E-SMLC via the Serving Mobility Management Entity (MME) and the serving eNodeB for the UE. LPP or LPP / LPPe messages can also be exchanged between the UE and the LMF via the Service Access and Mobility Management Function (AMF) and the Serving NR Node B (gNB) for the UE. LPP and LPP / LPPe can also be used to help support the OMA SUPL solution for supporting various radio access types of IP messaging (such as LTE, NR, and WiFi), where LPP or LPP / LPPe messages are exchanged between the SUPL-enabled terminal (SET) (the term for a UE with SUPL) and the SLP, and can be transmitted within SUPL messages such as SUPL POS or SUPL POS INIT messages.

[0046] Location servers and base stations (e.g., eNodeBs for LTE access) can exchange messages enabling the location server to (i) obtain location measurements of a specific UE from the base station, or (ii) obtain location information unrelated to a specific UE from the base station, such as the location coordinates of the base station antenna, the cells supported by the base station (e.g., cell identification), the cell timing of the base station, and / or parameters of signals transmitted by the base station (e.g., PRS signals). In the case of LTE access, the LPP A (LPPa) protocol can be used to transmit such messages between a base station acting as an eNodeB (eNB) and a location server acting as an E-SMLC. In the case of NR access, the NRPPA protocol can be used to transmit such messages between a base station acting as a gNodeB (gNB) and a location server acting as an LMF. Note that the terms "parameters" and "information elements" (IEs) are synonyms and are used interchangeably herein.

[0047] During positioning using signal transmissions in LTE and 5G NR, the UE typically acquires dedicated positioning signals, such as PRS, transmitted from base stations. These signals are used to generate the necessary measurements for the supported positioning technologies. The Positioning Reference Signal (PRS) is defined for 5G NR positioning to enable the UE to detect and measure more neighboring base stations or Transmit and Receive Points (TRPs). This involves downlink (DL) PRS from a reference base station and one or more neighboring stations. Based on the Time of Arrival (TOA) of the PRS from the reference base station and neighboring base stations, the UE can generate the DL Reference Signal Time Difference (RSTD) for DL ​​TDOA positioning, sometimes referred to as the Observed Time Difference of Arrival (OTDOA). In a similar process, the UE can transmit uplink reference signals for positioning to the reference base station and neighboring base stations, called the Sounding Reference Signal (SRS). The TOA of the SRS at the reference station and neighboring stations can be used to generate the UL RSTD for UL TDOA positioning, sometimes referred to as the Uplink Time Difference of Arrival (UTDOA).

[0048] As mentioned earlier, a base station can be a Transmit / Receive Point (TRP) for UE positioning. In some scenarios, it may be advantageous for one or more TRPs to be used by the UE (which can move within the network compared to a base station that is typically stationary). For example, a base station can provide PRS via an UP interface (called a Uu interface, such as LTE-Uu or NR-Uu). In the first scenario, the target UE for positioning is within range of the Uu interface used for DL ​​and within range of the Uu interface used for at least one anchor base station. The UE can be used as a TRP (which can be called an anchor for positioning) to assist in positioning. In this way, the anchor UE can transmit and receive PRS with the target UE via SL. Additional anchors (such as additional anchor UEs or additional base stations) can be used to increase the number of TRPs to a sufficient number of positioning (e.g., two or three TRPs) or to improve the accuracy of location estimation. In the second scenario, the target UE is not within range of the Uu interface of either the DL or UL of any base station. The anchor UE can be used to perform SL-only positioning. For example, a low-power device (such as a wearable device) may be within the range of multiple UEs but not within the range of the base station. The UE can be used to perform SL-only positioning of the wearable device. In a third scenario, the target UE is in the DL but not within the Uu interface range of the base station's UL. The anchor UE can be used to assist the UL portion (such as relaying information back to the base station or location server). For example, a target UE with limited transmission capabilities (such as a wearable device or other low-power device) may be able to receive from the base station on the DL but not transmit to the base station on the UL.

[0049] Support for SL-only and / or SL-assisted positioning is desirable. Because a UE may operate within a radio network, or may have lower transmission power than other UEs, some candidate anchor UEs may be better suited as anchor UEs than others. As described herein, anchor UEs can be selected or excluded for one or more target UEs. The selection of one or more candidate anchor UEs can be based on one or more of the following: measurement quality metrics (such as received signal (RS) power (RSRP) or signal-to-noise ratio (SNR) metrics used for positioning, the accuracy of positioning measurements of the candidate anchor UE, etc.); the operational status of the candidate anchor UE; or the geometrical precision factor (GDOP) associated with the candidate anchor UE. For example, a subset of one or more candidate anchor UEs can be selected from a plurality of candidate anchor UEs as potential anchors for one or more target UEs. As used herein, selecting one or more candidate anchor UEs can refer to selecting a plurality of candidate anchor UEs to exclude one or more candidate anchor UEs from being selected as anchors for one or more target UEs. In this manner, selection can refer to selecting a candidate anchor UE as an anchor, excluding a candidate anchor UE from being selected as an anchor, selecting a subset of candidate anchor UEs from a set of candidate anchor UEs, or selecting downwards from the set of candidate anchor UEs to remove one or more candidate anchor UEs from consideration as anchors. Selecting downwards from the set of candidate anchor UEs can be used herein to mean excluding a candidate anchor UE from consideration as an anchor. In one embodiment, the device obtains one or more positioning measurements of the candidate anchor UE and a measurement quality metric for each of the positioning measurements from one or more candidate anchor UEs among a plurality of candidate anchor UEs. The device also selects a plurality of candidate anchor UEs for positioning a target UE based on one or more measurement quality metrics from one or more candidate anchor UEs. In another embodiment, the device determines the operational state of a candidate anchor UE for one or more candidate anchor UEs among a plurality of candidate anchor UEs. The device also selects a plurality of candidate anchor UEs for positioning a target UE based on one or more operational states. In another embodiment, the device selects one or more anchor UEs from a plurality of candidate anchor UEs for positioning the target UE, wherein the selection is based on a plurality of GDOPs, each GDOP being determined by the target UE for different combinations of candidate anchor UEs from the plurality of candidate anchor UEs. The selection or exclusion of anchor UEs can be performed by the UE of the radio network or a location server. As used herein, determining the GDOP can refer to estimating or calculating the GDOP in any suitable manner. Although some instances describe the target UE determining the GDOP, the GDOP can be determined (e.g., estimated or calculated) by a location server, base station, or another suitable radio network entity (such as for UE-assisted positioning of the target UE).

[0050] Figure 1 illustrates an exemplary wireless communication system 100. The wireless communication system 100 (which may also be referred to as a wireless wide area network (WWAN) or a wireless network (e.g., a cellular network)) may include various base stations 102 and various UEs 104, wherein one or more of the base stations 102 and / or UEs 104 may sometimes be referred to herein as TRP 102 or 104. Base stations 102 may include macrocell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In one embodiment, a macrocell base station may include an eNB in ​​which the wireless communication system 100 corresponds to an LTE network, or a gNB in ​​which the wireless communication system 100 corresponds to a 5G network, or a combination of both, and a small cell base station may include femtocells, picocells, microcells, etc.

[0051] Base stations 102 can collectively form a RAN and are connected to a core network 170 (e.g., an Evolved Packet Core (EPC) or Next Generation Core (NGC)) via backhaul link 122, and to location servers 172 via the core network 170 interface. These location servers may include one or more location servers. Among other functions, base stations 102 can also perform functions related to one or more of the following: user data transmission, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of Non-Access Layer (NAS) messages, NAS node selection, synchronization, RAN sharing, Multimedia Broadcast Multicast Service (MBMS), user and device tracking, RAN Information Management (RIM), paging, location, and warning message delivery. Base stations 102 can communicate with each other directly or indirectly (e.g., via EPC / NGC) on backhaul link 134, which can be wired or wireless.

[0052] Base station 102 can wirelessly communicate with UE 104. Each of base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. In one case, each base station 102 in coverage area 110 can support one or more cells. A "cell" is a logical communication entity used (e.g., on a frequency resource referred to as a carrier frequency, component carrier, carrier, band, etc.) to communicate with a base station or UE, and can be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) used to distinguish cells operating via the same or different carrier frequencies. In some cases, different cells can be configured according to different protocol types that can provide access for different types of UEs (e.g., Machine Type Communication (MTC), Narrowband IoT (NB-IoT), Enhanced Mobile Broadband (eMBB), or others). In some cases, the term "cell" can also refer to a geographic coverage area (e.g., a sector) of a base station, as long as a carrier frequency can be detected and used for communication within certain portions of geographic coverage area 110.

[0053] Although the geographic coverage areas 110 of adjacent macrocell base stations 102 may partially overlap (e.g., in delivery areas), some geographic coverage areas 110 may substantially overlap with larger geographic coverage areas 110. For example, a small cell base station 102' may have a coverage area 110' that substantially overlaps with the coverage areas 110 of one or more macrocell base stations 102. A network that includes both small cell base stations and macrocell base stations may be referred to as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs) that can provide services to restricted groups referred to as Closed Subscriber Groups (CSGs).

[0054] The communication link 120 between base station 102 and UE 104 may include UL (also known as reverse link) transmission from UE 104 to base station 102 and / or downlink (DL) (also known as forward link) transmission from base station 102 to UE 104. The communication link 120 may use MIMO antenna technologies including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may be transmitted via one or more carrier frequencies. Carrier allocation relative to DL and UL may be asymmetric (e.g., more or fewer carriers may be allocated to DL compared to UL).

[0055] The wireless communication system 100 may also include a wireless local area network (WLAN) access point (AP) 150, which communicates with a WLAN station (STA) 152 via a communication link 154 in unlicensed spectrum (e.g., 5 GHz). When communicating in unlicensed spectrum, the WLAN STA 152 and / or WLAN AP 150 may perform an idle channel assessment (CCA) before communication to determine whether the channel is available.

[0056] Small cell base station 102' can operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, small cell base station 102' can employ LTE or 5G technology and use the same 5 GHz unlicensed spectrum as WLAN AP 150. Using LTE / 5G in unlicensed spectrum can increase coverage and / or capacity of the access network. LTE in unlicensed spectrum can be referred to as LTE Unlicensed (LTE-U), Licensed Assisted Access (LAA), or MulteFire.

[0057] The wireless communication system 100 may also include a millimeter-wave (mmW) base station 180, which can communicate with the UE 182 at mmW and / or near-mmW frequencies. Extremely high frequency (EHF) is a portion of the RF spectrum in the electromagnetic spectrum. EHF ranges from 30 GHz to 300 GHz, with wavelengths between 1 mm and 10 mm. Radio waves in this band can be referred to as millimeter waves. Near-mmW may extend down to 3 GHz with a wavelength of 100 mm. Ultra-high frequency (SHF) bands extend between 3 GHz and 30 GHz, also known as centimeter waves. Communication using mmW / near-mmW radio bands has high path loss and relatively short range. The mmW base station 180 and the UE 182 can utilize beamforming (transmission and / or reception) on the mmW communication link 184 to compensate for the extremely high path loss and short range. Furthermore, it should be understood that in alternative configurations, one or more base stations 102 may also use mmW or near-mmW and beamforming for transmission. Therefore, it should be understood that the foregoing description is merely an example and should not be construed as limiting the various states disclosed herein.

[0058] Transmit beamforming is a technique used to focus RF signals in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectional). Using transmit beamforming, the network node determines the location of a given target device (e.g., a UE) (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thus providing a faster (in terms of data rate) and stronger RF signal to the receiving device. To change the directivity of the RF signal during transmission, the network node can control the phase and relative amplitude of the RF signal at each of one or more transmitters broadcasting the RF signal. For example, the network node can use an array of antennas (called a "phased array" or "antenna array") that creates a beam that can be "steered" to point RF waves in different directions without actually moving the antennas. Specifically, RF currents from the transmitters are fed to the individual antennas with the correct phase relationship, causing the radio waves from the individual antennas to combine to increase radiation in the desired direction while canceling out radiation in undesired directions.

[0059] In receive beamforming, a receiver uses a receive beam to amplify the RF signal detected on a given channel. For example, the receiver can increase the gain setting and / or adjust the phase setting of the antenna array in a specific direction to amplify the RF signal received from that direction (e.g., increase its gain level). Therefore, when it is said that a receiver forms a beam in a certain direction, this means that the beam gain in that direction is higher than the beam gain along other directions, or that the beam gain in that direction is the highest compared to the beam gain of all other receive beams available to the receiver in that direction. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference plus noise ratio (SINR), signal-to-noise ratio (SNR), etc.) of the RF signal received from that direction.

[0060] In 5G, the spectrum in which radio nodes (e.g., base stations 102 / 180, UE 104 / 182) operate is divided into several frequency ranges: FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In multi-carrier systems such as 5G, one of the carrier frequencies is referred to as the "primary carrier," "anchor carrier," "primary serving cell," or "PCell," while the remaining carrier frequencies are referred to as "secondary carriers," "secondary serving cells," or "Scell." In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) used by UE 104 / 182 and the cell in which UE 104 / 182 performs the initial Radio Resource Control (RRC) connection establishment procedure or initiates the RRC connection re-establishment procedure. The primary carrier carries all shared and UE-specific control channels. A subcarrier is a carrier operating on a second frequency (e.g., FR2). Once an RRC connection is established between UE 104 and the anchor carrier, it can be configured and used to provide additional radio resources. A subcarrier may contain only the necessary signaling information and signals; for example, since the primary uplink and downlink carriers are typically UE-specific, UE-specific signaling information and signals may not exist in the subcarrier. This means that different UEs 104 / 182 within a cell can have different downlink primary carriers. The same applies to the uplink primary carrier. The network can change the primary carrier of any UE 104 / 182 at any time. For example, this can be done to balance the load on different carriers. Because a "serving cell" (whether PCell or SCell) corresponds to a carrier frequency / component carrier on which some base station is communicating, the terms "cell," "serving cell," "component carrier," and "carrier frequency" are used interchangeably.

[0061] For example, still referring to Figure 1, one of the frequencies used by macrocell base station 102 can be an anchor carrier (or "PCell"), while the other frequencies used by macrocell base station 102 and / or mmW base station 180 can be subcarriers ("Scell"). Simultaneous transmission and / or reception on multiple carriers allows UE 104 / 182 to significantly improve its data transmission and / or reception rates. For example, compared to the data rate achieved by a single 20 MHz carrier, two aggregated 20 MHz carriers in a multi-carrier system would theoretically result in twice the data rate (i.e., 40 MHz).

[0062] The wireless communication system 100 may also include one or more UEs, such as UE 190, indirectly connected to one or more communication networks via one or more side links (SLs) such as device-to-device (D2D) peer-to-peer (P2P) links. In the example of Figure 1, UE 190 has a D2D P2P link 192, wherein UE 190 has a D2D P2P link 192 with one of UEs 104 connected to one of base stations 102 (e.g., UE 190 can indirectly obtain cellular connectivity through it), and has a D2D P2P link 194 with a WLAN STA 152 connected to a WLAN AP 150 (UE 190 can indirectly obtain WLAN-based internet connectivity through it). In this example, D2D P2P links 192 and 194 may be supported by any known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, etc. In this example, UE 190 can be a relay UE between UE 152 and base station 102. One or more UEs can be relay UEs between the device and the base station.

[0063] The wireless communication system 100 may also include a UE 164, which can communicate with the macrocell base station 102 via communication link 120 and / or with the mmW base station 180 via mmW communication link 184. For example, the macrocell base station 102 may support PCells and one or more SCells for the UE 164, and the mmW base station 180 may support one or more SCells for the UE 164.

[0064] The target UE 104 for location can be within the radio range of one or more base stations 102 (which can be TRP 102 for locating the target UE 104). Additionally or alternatively, the target UE 104 can be within the radio range of one or more other UEs 104 (which can be anchor UEs acting as TRP 104 for locating the target UE 104). For example, the target UE 104 can be within the range of at least two or three devices capable of operating as TRPs. The anchor base station can transmit a PRS (DL-PRS) to one or more target UEs on the DL, and the anchor UE can transmit a PRS (SL-PRS) to one or more target UEs on the SL.

[0065] Figure 2 illustrates a block diagram of the design 200 of base station 102 and UE 104, which can be one of the base stations and one of the UEs in Figure 1. Base station 102 can be equipped with T antennas 234a to 234t, and UE 104 can be equipped with R antennas 252a to 252r, where typically T ≥ 1 and R ≥ 1.

[0066] At base station 102, transmission processor 220 can receive data from one or more UEs from data source 212, selecting one or more modulation and decoding schemes (MCS) for each UE based at least in part on Channel Quality Indicators (CQIs) received from the UEs, processing (e.g., encoding and modulating) the data of each UE based at least in part on the MCS selected for the UEs, and providing data symbols for all UEs. Transmission processor 220 can also process system information (e.g., information for semi-static resource allocation (SRPI), etc.) and control information (e.g., CQI requests, permission, upper-layer signaling, etc.) and provide management burden symbols and control symbols. Transmission processor 220 can also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signal (PSS) and secondary synchronization signal (SSS)). If applicable, the Transmit (TX) Multiple-Input Multiple-Output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, management burden symbols, and / or reference symbols, and can provide T output symbol streams to T modulators (MODs) 232a to 232t. Each modulator 232 can process its corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 can further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a to 232t can be transmitted via T antennas 234a to 234t, respectively. According to the various states described in more detail below, position coding can be used to generate synchronization signals to convey additional information.

[0067] At UE 104, antennas 252a to 252r can receive downlink signals from base station 102 and / or other base stations, and can respectively provide the received signals to demodulators (DEMODs) 254a to 254r. Each demodulator 254 can adjust (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain an input sample. Each demodulator 254 can further process the input sample (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 can obtain received symbols from all R demodulators 254a to 254r, and, if applicable, perform MIMO detection on the received symbols and provide the detected symbols. Receiver processor 258 can process (e.g., demodulate and decode) the detected symbols, provide the decoded data of UE 104 to data slot 260, and provide the decoded control information and system information to controller / processor 280. The channel processor can determine the Received Reference Power (RSRP), Received Signal Strength Indicator (RSSI), Received Reference Quality (RSRQ), Channel Quality Indicator (CQI), etc. In some cases, one or more components of UE 104 can be included in the housing.

[0068] On the uplink, at UE 104, transmission processor 264 can receive and process data from data source 262 and control information from controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). Transmission processor 264 can also generate reference symbols for one or more reference signals. If applicable, the symbols from transmission processor 264 can be pre-encoded by TX MIMO processor 266, then further processed by modulators 254a to 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to base station 102. At base station 102, uplink signals from UE 104 and other UEs can be received by antenna 234, processed by demodulator, detected by MIMO detector 236 (if applicable), and further processed by receiver processor 238 to obtain decoded data and control information transmitted by UE 104. The receiver processor 238 can provide decoded data to the data slot 239 and decoded control information to the controller / processor 240. The base station 102 may include a communication unit 244 and communicates with the network controller 289 via the communication unit 244. The network controller 289 may include a communication unit 294, a controller / processor 290, and memory 292.

[0069] The controller / processor 240 of base station 102, the controller / processor 280 of UE 104, the controller 290 of network controller 289 (which may be location server 172), and / or any other element of FIG. 2 may perform one or more technologies associated with supporting the location services of the UE, as described in more detail elsewhere herein. For example, the controller / processor 240 of base station 102, the controller 290 of network controller 289, the controller / processor 280 of UE 104, and / or one or more other elements of FIG. 2 may perform or direct operations such as those illustrated in the figures and described herein. Memory 242, 282, and 292 may store data and program code for base station 102, UE 104, and network controller 289, respectively. In some cases, memory 242 and / or memory 282 and / or memory 292 may include non-transitory computer-readable media storing one or more instructions for wireless communication. For example, when one or more instructions are executed by one or more processors of base station 102, network controller 289, and / or UE 104, they can perform or direct the operation of the procedures described herein. Scheduler 246 can schedule UEs to perform data transmission on downlinks and / or uplinks.

[0070] Location server 172 (which may include network controller 289) can be configured to downselect or select TRPs (including one or more anchor UEs) for positioning, determine and indicate resources to be used for positioning (such as specific RS resources or PRS formats), determine the positioning of one or more UEs in the wireless network, store positioning information of one or more UEs, or perform other operations associated with the positioning of one or more UEs in the wireless network. Positioning information can be used for various operations, such as cell selection, handover, beamforming, or location determination, or other states of the wireless network 100.

[0071] As noted above, Figure 2 is provided as an example. Other examples may differ from those described with respect to Figure 2. For example, although Figure 2 illustrates communication between base station 102 and UE 104, communication can occur between two UEs 104 via a side link. In this way, as illustrated in Figure 2, UE 104 and another UE 104 can communicate with each other via a side link. The UE in this example can be a target UE, a candidate anchor UE, or an anchor UE (e.g., a UE selected as a TRP) for positioning.

[0072] Base stations or UEs can broadcast, unicast, or multicast one or more PRSs in a wireless network (such as in a cellular network including LTE and / or 5G technologies). In the frequency domain, the available bandwidth can be divided into evenly spaced orthogonal subcarriers (also known as "tones" or "bins"). For example, for a normal-length cyclic prefix (CP) using, for example, a 15 kHz interval, subcarriers can be classified into groups of twelve (12) subcarriers. The resources of an OFDM symbol length in the time domain and a subcarrier in the frequency domain can be called resource elements (REs). In this example, each class of 12 subcarriers and 14 OFDM symbols is called a resource block (RB), and in the example above, the number of subcarriers in a resource block can be written as For a given channel bandwidth, the number of available resource blocks (also known as transmission bandwidth configuration) on each channel is expressed as: For example, for a 3 MHz channel bandwidth in the above example, the number of available resource blocks per channel is provided by the following formula: It should be noted that the frequency components of a resource block (e.g., 12 subcarriers) are called physical resource blocks (PRBs).

[0073] Base stations can transmit radio frames or other physical layer signaling sequences supporting PRS signals (i.e., downlink (DL) PRS) based on frame configurations similar to those in the examples above, which can be measured and used for target UE location estimation. UEs can also transmit radio frames or other physical layer signaling sequences supporting PRS signals (i.e., sidelink (SL) PRS) based on frame configurations similar to or different from those in the examples above, which can also be measured and used for target UE location estimation. Other types of wireless nodes in the wireless network (e.g., distributed antenna systems (DAS), remote radio heads (RRHs), access points, etc.) can also be configured to transmit PRS configured in a manner similar to (or identical to) those described above.

[0074] A set of resource elements used to transmit PRS signals is called a "PRS resource". The set of resource elements can span multiple PRBs in the frequency domain and "N" (e.g., one or more) consecutive symbols within a time slot in the time domain. A "PRS resource set" is a group of PRS resources used to transmit PRS signals, where each PRS resource has a PRS resource identifier (ID). Furthermore, PRS resources in a PRS resource set are associated with the same TRP. The PRS resource ID in the PRS resource set is associated with a single beam transmitted from a single TRP (where a TRP can transmit one or more beams). It should be noted that this has no effect on whether the UE knows the TRP and beam on which the signal is transmitted.

[0075] PRS can be transmitted within dedicated positioning subframes classified as positioning opportunities. A PRS opportunity is an example of a window (e.g., a continuous time slot) in which a periodic repetition of PRS is expected to be transmitted. Each periodic repetition window may include a group of one or more consecutive PRS opportunities. Each PRS opportunity may include a number of consecutive positioning subframes of N PRS. PRS positioning opportunities of cells supported by a base station or UE may occur periodically at intervals. Multiple PRS opportunities may be associated with the same PRS resource configuration; in this case, each such opportunity is referred to as a "PRS resource opportunity," etc.

[0076] PRS can be transmitted at constant power. It can also be transmitted at zero power (i.e., silent). Silencing is useful when PRS signals from different cells overlap due to simultaneous or near-simultaneous occurrences, as it shuts off periodically scheduled PRS transmissions. In this case, PRS signals from some cells may be silenced, while PRS signals from other cells may be transmitted (e.g., at constant power). Silencing can help the UE acquire signals from unsilenced PRS signals and measure Time of Arrival (TOA) and Reference Signal Time Difference (RSTD) (by avoiding interference from silenced PRS signals). Silencing can be considered as not transmitting PRS for a specific cell at a given positioning time. Silence patterns (also called silence sequences) can be signaled to the UE using bit strings (e.g., using the LTE Positioning Protocol (LPP)). For example, in a bit string signaling the silence pattern, if the bit at position j is set to "0", the UE can infer that the PRS is silenced for the j-th positioning time.

[0077] To further improve the audibility of the PRS, the location subframe can be a low-interference subframe transmitted without a user data channel. Therefore, in an ideally synchronized network, the PRS may be interfered with by the PRS of other cells with the same PRS pattern index (i.e., the same frequency shift), but not by interference from data transmission. The frequency shift can be defined as the PRS ID of the cell or other transport point (TP) (denoted as...). The function, or defined as a Solid Cell Identifier (PCI) (represented as) in the absence of an assigned PRS ID. The function of ) results in an effective frequency reuse factor of six (6).

[0078] Similarly, to improve the audibility of PRS (e.g., when PRS bandwidth is limited, such as when there are only six resource blocks corresponding to a bandwidth of 1.4 MHz), the frequency band used for consecutive PRS positioning timings (or consecutive PRS sub-frames) can be changed in a known and predictable manner via frequency hopping. Furthermore, the cell supported by the base station or UE can support more than one PRS configuration, where each PRS configuration may include different frequency shifts (vshifts), different carrier frequencies, different bandwidths, different code sequences, and / or different PRS positioning timing sequences, where each positioning timing has a specific number of sub-frames (NPRS) and a specific period (TPRS). In some implementations, one or more PRS configurations supported by the cell can be used for directional PRS and can subsequently have additional different characteristics, such as different transmission directions, different horizontal angle ranges, and / or different vertical angle ranges.

[0079] As mentioned above, the PRS configuration (including PRS transmission / silent scheduling) is signaled to the UE so that the UE can perform PRS positioning measurements. In this way, the UE is not expected to blindly perform detection of the PRS configuration.

[0080] Similar to the DL PRS transmitted by the base station as discussed above, the target UE can transmit UL PRS and / or SL PRS for positioning. UL PRS can be, for example, a detection reference signal (SRS) for positioning. SL PRS can be a signal similar to SRS.

[0081] Using DL PRS received from the base station or SL PRS received from the anchor UE and / or UL PRS transmitted to the base station or SL PRS transmitted to the anchor UE, the target UE, anchor UE, base station (such as gNB), or other devices on the wireless network can perform various positioning measurements (also known as position measurements). Other metrics that can be determined include one or more of the following: measurement quality metrics (which can indicate the quality of the UE's positioning measurements or signal quality, such as RSRP or SNR metrics); the anchor UE's operational status; or GDOP associated with TRP.

[0082] Figure 3 illustrates a UE 300 as an example of UE 104, which is capable of providing location services over a wireless network such as wireless network 100. UE 300 includes a computing platform comprising at least one processor 310, memory 311 including software (SW) 312, one or more sensors 313, a transceiver interface 314 for a transceiver 315, a user interface 316, a satellite positioning system (SPS) receiver 317, a camera 318, and a positioning device (PD) 319. The processor 310, memory 311, (one or more) sensors 313, transceiver interface 314, user interface 316, SPS receiver 317, camera 318, and positioning device 319 can be communicatively coupled to each other via a bus 320 (which can be configured, for example, for optical and / or electrical communication). UE 300 may omit one or more of the illustrated devices (e.g., camera 318, SPS receiver 317, and / or one or more sensors 313, etc.). Processor 310 may include one or more smart hardware devices, such as a central processing unit (CPU), microcontroller, application-specific integrated circuit (ASIC), etc. Processor 310 may include multiple processors, including application processor 330, digital signal processor (DSP) 331, modem processor 332, video processor 333, and / or sensor processor 334. One or more of processors 330-334 may include multiple devices (e.g., multiple processors). For example, sensor processor 334 may include processors for radar, ultrasonic, and / or lidar, etc. Modem processor 332 may support dual SIM / dual connectivity (or even more SIMs). For example, one SIM (Subscriber Identity Module or User Identification Module) may be used by the original equipment manufacturer (OEM), while another SIM may be used by the end user of UE 300 for connectivity. Memory 311 is a non-transitory storage medium that may include random access memory (RAM), flash memory, optical disk memory, and / or read-only memory (ROM). Memory 311 stores software 312, which may be processor-readable and processor-executable software code containing instructions configured, at execution, to cause processor 310 to operate as a dedicated computer program designed to perform the various functions described herein. Alternatively, software 312 may not be directly executable by processor 310, but may be configured to cause processor 310 to operate as a dedicated computer, for example, at compile and execution time, to perform the various functions described herein. This description may only relate to processor 310 performing functions, but this also includes other implementations, such as processor 310 performing software and / or firmware. The description may simply refer to processor 310 performing a function as processor 310 performing that function.This description may be abbreviated as UE 300 performing a function by one or more suitable elements of UE 300. In addition to and / or as a replacement for memory 311, processor 310 may include memory storing instructions.

[0083] The configuration of UE 300 shown in Figure 3 is an example and not a limitation of this application (including the requested item), and other configurations may be used. For example, an exemplary configuration of the UE includes one or more of processors 330-334 of processor 310, memory 311, and wireless transceiver 340. Other exemplary configurations include one or more of processors 330-334 of processor 310, memory 311, wireless transceiver 340, and one or more of sensors 313, user interface 316, SPS receiver 317, camera 318, PD 319, and / or wired transceiver 350.

[0084] UE 300 may include a modem processor 332, which is capable of performing baseband processing on signals received and down-converted by transceiver 315 and / or SPS receiver 317. The modem processor 332 may perform baseband processing on signals to be up-converted for transmission by transceiver 315. Alternatively, baseband processing may be performed by processor 330 and / or DSP 331. However, other configurations may be used to perform baseband processing.

[0085] UE 300 may include one or more sensors 313, which may include one or more of various types of sensors, such as one or more inertial sensors, one or more barometric pressure sensors, one or more magnetometers, one or more environmental sensors, one or more optical sensors, one or more weight sensors, and / or one or more radio frequency (RF) sensors. An inertial measurement unit (IMU) may include, for example, one or more accelerometers (e.g., responding collectively to the acceleration of UE 300 in three dimensions) and / or one or more gyroscopes capable of detecting motion, including rotation of UE 300. One or more sensors 313 may include one or more magnetometers to determine (e.g., orientation relative to magnetic north and / or true north), which may be used for any of a variety of purposes, such as supporting one or more compass applications. One or more environmental sensors may include, for example, one or more temperature sensors, one or more atmospheric pressure sensors, one or more ambient light sensors, one or more camera imagers, and / or one or more microphones. One or more sensors 313 may generate analog and / or digital signal indications, which may be stored in memory 311 and processed by DSP 331 and / or processor 330 to support one or more applications, such as applications involving positioning and / or navigation operations.

[0086] One or more sensors 313 can be used for relative position measurement, relative position determination, motion determination, etc. Information detected by one or more sensors 313 can be used for motion detection, relative displacement, dead reckoning, sensor-based position determination, and / or sensor-assisted position determination. One or more sensors 313 can be used to determine whether the UE 300 is stationary or moving (including rotating) and / or whether to report certain useful information about the UE 300's movement. For example, based on information obtained / measured by one or more sensors, the UE 300 can notify / report that it has detected movement or that it has moved, and report relative displacement / distance (e.g., via dead reckoning, or sensor-based position determination, or sensor-assisted position determination enabled by one or more sensors 313). In another example, for relative positioning information, the sensor / IMU can be used to determine the angle and / or orientation of another device relative to the UE 300.

[0087] The IMU can be configured to provide measurements of the direction and / or velocity of motion of the UE 300, which can be used for relative position determination. For example, one or more accelerometers and / or one or more gyroscopes of the IMU can detect the linear acceleration and rotational velocity of the UE 300, respectively. The linear acceleration and rotational velocity measurements of the UE 300 can be integrated over time to determine the transient direction and displacement of the UE 300. The transient direction and displacement can be integrated to track the position of the UE 300. For example, a reference position of the UE 300 can be determined for a given moment, for example using an SPS receiver 317 (and / or via some other means), and measurements acquired after that moment from (one or more) accelerometers and (one or more) gyroscopes can be used for dead reckoning to determine the current position of the UE 300 based on its movement (direction and distance) relative to the reference position.

[0088] One or more magnetometers can determine the magnetic field strength in different directions, which can be used to determine the orientation of the UE 300. For example, the orientation can be used to provide a digital compass for the UE 300. The magnetometer can be a two-dimensional magnetometer configured to detect and provide indications of magnetic field strength in two orthogonal dimensions. Alternatively, the magnetometer can be a three-dimensional magnetometer configured to detect and provide indications of magnetic field strength in three orthogonal dimensions. The magnetometer can provide a component for sensing the magnetic field and providing an indication of the magnetic field to, for example, a processor 310.

[0089] One or more atmospheric pressure sensors can determine the air pressure, which can be used to determine the height of the UE 300 in a building or its current floor level. For example, differential pressure readings can be used to detect when the UE 300 has changed its floor level and the number of floors that have changed. One or more atmospheric pressure sensors can provide components for sensing air pressure and providing air pressure indications to, for example, a processor 310.

[0090] Transceiver 315 may include one or both of a wireless transceiver 340 or a wired transceiver 350, which are configured to communicate with other devices via wireless and wired connections, respectively. For example, wireless transceiver 340 may include a transmitter 342 and a receiver 344 coupled to one or more antennas 346 for transmitting and / or receiving wireless signals 348 (e.g., on one or more uplink channels and / or one or more sidelink channels). In some embodiments, wireless signals 348 may be converted into wired (e.g., electrical and / or optical) signals and from wired (e.g., electrical and / or optical) signals, and wired signals may be converted into wireless signals 348. Therefore, transmitter 342 may include multiple transmitters that may be individual elements or combined / integrated elements, and / or receiver 344 may include multiple receivers that may be individual elements or combined / integrated elements. The wireless transceiver 340 can be configured to transmit signals according to various Radio Access Technologies (RATs) (e.g., with TRP and / or one or more other devices), such as 5G New Radio (NR), GSM (Global System for Mobile Communications), UMTS (Universal Mobile Telecommunications System), AMPS (Advanced Mobile Telephone System), CDMA (Code Division Multiple Access), WCDMA (Wideband CDMA), LTE (Long Term Evolution), LTE Direct (LTE-D), 6GPP LTE-V2X (PC5), IEEE 802.11 (including IEEE 802.11p), WiFi, WiFi Direct (WiFi-D), Bluetooth®, Zigbee, etc. New Radio can use millimeter wave frequencies and / or sub-6 GHz frequencies. If the UE 300 is to include a wired transceiver, the wired transceiver 350 may include a transmitter 352 and a receiver 354 configured for wired communications. Transmitter 352 may include multiple transmitters, which may be individual components or combined / integrated components, and / or receiver 354 may include multiple receivers, which may be individual components or combined / integrated components. Wired transceiver 350 may be configured for, for example, optical communication and / or electrical communication. Transceiver 315 may be communicatively coupled to transceiver interface 314, for example, via optical and / or electrical connections. Transceiver interface 314 may be at least partially integrated with transceiver 315.

[0091] Antenna 346 may include an antenna array. The antenna array may be capable of transmit beamforming or receive beamforming, for example, by increasing a gain setting and / or adjusting the phase setting of the antenna array in a particular direction to amplify the RF signal received from that direction (e.g., increasing the gain level of the RF signal). Antenna 346 may also include a plurality of antenna panels, each capable of beamforming. Antenna 346 may be adjustable, for example, selecting one or more antennas to control the received beam from the base station. For example, a reduced number of beams or a single beam may be selected to receive a wide-angle beam, thereby reducing power consumption, while an increased number of antennas may be selected in the antenna array when the transmit beam is relatively narrow.

[0092] User interface 316 may include one or more of a number of devices, such as speakers, microphones, display devices, vibration devices, keyboards, touch screens, etc. User interface 316 may include any more than one of these devices. User interface 316 may be configured to enable a user to interact with one or more applications hosted by UE 300. For example, user interface 316 may store indications of analog and / or digital signals in memory 311 in response to actions from the user processed by DSP 331 and / or processor 330. Similarly, applications hosted on UE 300 may store indications of analog and / or digital signals in memory 311 to present output signals to the user. User interface 316 may include audio input / output (I / O) devices, including, for example, speakers, microphones, digital-analog circuitry systems, analog-digital circuitry systems, amplifiers and / or gain control circuitry systems (including any more than one of these devices). Other configurations of the audio I / O devices may be used. Alternatively, the user interface 316 may include, for example, one or more touch sensors on the keyboard and / or touch screen of the user interface 316 that are capable of responding to touch and / or pressure.

[0093] SPS receiver 317 (e.g., a Global Positioning System (GPS) receiver or other Global Navigation Satellite System (GNSS) receiver) can receive and acquire SPS signal 360 via SPS antenna 362. Antenna 362 is configured to convert the radio signal 360 into a wired signal (e.g., an electrical or optical signal) and can be integrated with antenna 346. SPS receiver 317 can be configured to process the acquired SPS signal 360, in whole or in part, to estimate the location of UE 300. For example, SPS receiver 317 can be configured to use SPS signal 360 via trilateration / polylateration to determine the location of UE 300. In conjunction with SPS receiver 317, processor 330, memory 311, DSP 331, PD 319, and / or one or more additional dedicated processors (not shown) can be used to process the acquired SPS signal, in whole or in part, and / or calculate the estimated location of UE 300. Memory 311 may store indications (e.g., measurements) of SPS signal 360 and / or other signals (e.g., signals acquired from wireless transceiver 340) for use in performing positioning operations. General-purpose processor 330, DSP 331, PD 319 and / or one or more additional dedicated processors and / or memory 311 may provide or support a positioning engine for processing measurements to estimate the position of UE 300.

[0094] UE 300 may include a camera 318 for capturing still or moving images. Camera 318 may include, for example, an imaging sensor (e.g., a charge-coupled device or a CMOS imager), a lens, an analog-to-digital circuitry system, a frame buffer, etc. Additional processing, conditioning, encoding, and / or compression of the signals representing the captured images may be performed by a general-purpose processor 330 and / or a DSP 331. Alternatively, a video processor 333 may perform conditioning, encoding, compression, and / or manipulation of the signals representing the captured images. The video processor 333 may decode / decompress stored image data for presentation on a display device (not shown), such as a user interface 316.

[0095] Positioning device (PD) 319 can be configured to determine the location of UE 300, the movement of UE 300, and / or the relative position of UE 300, and / or time. For example, PD 319 can communicate with SPS receiver 317 and radio transceiver 340 and / or include some or all of them. PD 319 may be combined with processor 310 and memory 311 as appropriate to perform at least a portion of one or more positioning methods, although the description herein may only relate to PD 319 of processor 310 being configured to perform or be performing according to (one or more) positioning methods. PD 319 may additionally or alternatively be configured to use trilateration / polylateration with ground-based signals (e.g., at least some of signals 348) to determine the location of UE 300 to aid in obtaining and using SPS signal 360 or both. PD 319 can be configured to determine the location of UE 300 using one or more other technologies (e.g., location dependent on the UE's self-reported location (e.g., part of the UE's positioning beacon)), and can use a combination of technologies (e.g., SPS and terrestrial positioning signals) to determine the location of UE 300. PD 319 may include one or more sensors 313 (e.g., one or more gyroscopes, one or more accelerometers, one or more magnetometers, etc.) that can sense the orientation and / or motion of UE 300 and provide indications thereof. Processor 310 (e.g., processor 330 and / or DSP 331) can be configured to use these indications to determine the motion of UE 300 (e.g., velocity vector and / or acceleration vector). PD 319 can be configured to provide indications of uncertainty and / or error in the determined positioning and / or motion.

[0096] Memory 311 may store software 312 containing executable code or software instructions that, when executed by processor 310, enable processor 310 to operate as a dedicated computer programmed to perform the functions disclosed herein. As shown, memory 311 may include one or more elements or modules that can be implemented by processor 310 to perform the disclosed functions. Although elements or modules are shown as software 312 executable by processor 310 in memory 311, it should be understood that elements or modules may be stored in another computer-readable medium or may be dedicated hardware in or outside processor 310. Multiple software modules and data tables may reside in memory 311 and be used by processor 310 to manage both communications and the functions described herein simultaneously. It should be understood that the organization of the contents of memory 311 shown is merely exemplary, and therefore the functionality of modules and / or data structures may be combined, separated, and / or structured in different ways depending on the specific implementation.

[0097] For example, memory 311 may include an anchor UE selection communication period module 372, which, when implemented by one or more processors 310, configures one or more processors 310 to participate in a communication period used to determine whether UE 300 or another UE is used for positioning, which can be UE-based positioning or UE-assisted positioning, as described herein. For example, one or more processors 310 may be configured to determine a measurement quality metric (such as RSRP, SNR, accuracy of positioning estimation) or action state or motion metric of UE 300, and the measurement quality metric or action state may be used to select or exclude UE 300 from being used as a TRP or to select UE 300 as a TRP for positioning. GDOP may also be determined or may be used for down-selection or selection. Although the anchor UE selection communication period module 372 is described as software included in memory 311, the anchor UE selection communication period module 372 may be a hardware module, a software module, or a combination of hardware and software. For example, the module may include one or more application-specific integrated circuits (ASICs), executable code, or a combination of both.

[0098] Figure 4 illustrates base station 400, an example of base station 102 capable of supporting location services in a wireless network (e.g., wireless network 100). Base station 400 includes a computing platform comprising at least one processor 410, memory 411 including software (SW) 412, and transceiver 415. Processor 410, memory 411, and transceiver 415 may be communicatively coupled to each other via bus 420 (which may be configured, for example, for optical and / or electrical communication). One or more of the shown devices may be omitted from base station 400, or base station 400 may include one or more devices not shown. Processor 410 may include one or more smart hardware devices, such as a central processing unit (CPU), microcontroller, application-specific integrated circuit (ASIC), etc. Processor 410 may include multiple processors (e.g., one or more of application processors, DSPs, modem processors, video processors, and / or sensor processors, similar to those shown in Figure 3). Memory 411 is a non-transitory storage medium that may include random access memory (RAM), flash memory, optical disk memory, and / or read-only memory (ROM). Memory 411 stores software 412, which may be processor-readable and processor-executable software code containing instructions configured to, when executed, cause processor 410 to operate as a dedicated computer program designed to perform the various functions described herein. Alternatively, software 412 may not be directly executable by processor 410, but may be configured to cause processor 410 to operate as a dedicated computer, for example, during compilation and execution, to perform the various functions described herein. This description may refer only to processor 410 performing a function, but it also includes other implementations, such as processor 410 performing software and / or firmware. This description may simply refer to one or more processors included in processor 410 performing a function as processor 410 performing the function. This description may simply refer to one or more suitable elements of base station 400 performing a function as base station 400 performing the function. In addition to and / or as a replacement for memory 411, processor 410 may include memory storing instructions.

[0099] Transceiver 415 may include a wireless transceiver 440 or a wired transceiver 450, configured to communicate with other devices via wireless and wired connections, respectively. For example, wireless transceiver 440 may include a transmitter 442 and a receiver 444 coupled to one or more antennas 446 for transmitting and / or receiving wireless signals 448 (e.g., on one or more uplink channels and / or one or more downlink channels) and converting signals from wireless signals 448 into wired (e.g., electrical and / or optical) signals, and from wired (e.g., electrical and / or optical) signals into wireless signals 448. Antenna 446 is one or more antenna arrays capable of beamforming and transmitting and receiving beams, including beams for transmitting or receiving signals for location services (including PRS). Alternatively or concurrently, signals may be transmitted omnidirectionally. Transmitter 442 may include multiple transmitters, which may be individual components or combined / integrated components, and / or receiver 444 may include multiple receivers, which may be individual components or combined / integrated components. Wireless transceiver 440 may be configured to transmit signals according to various Radio Access Technologies (RATs) (e.g., with UE 300, one or more other UEs, and / or one or more other devices), such RATs include 5G New Radio (NR), GSM (Global System for Mobile Communications), UMTS (Universal Mobile Telecommunications System), AMPS (Advanced Mobile Telephone System), CDMA (Code Division Multiple Access), WCDMA (Wideband CDMA), LTE (Long Term Evolution), LTE Direct (LTE-D), 6GPP LTE-V2X (PC5), IEEE 802.11 (including IEEE 802.11p), WiFi, WiFi Direct (WiFi-D), Bluetooth®, Zigbee, etc. Wired transceiver 450 may include a transmitter 452 and a receiver 454 configured for wired communication, for example, to send communications to and receive communications from a location server 172. Transmitter 452 may include multiple transmitters, which may be individual components or combined / integrated components, and / or receiver 454 may include multiple receivers, which may be individual components or combined / integrated components. Wired transceiver 450 may be configured, for example, for optical communication and / or electrical communication.

[0100] The configuration of base station 400 shown in Figure 4 is an example and not a limitation of this case, including the request items, and other configurations may be used. For example, the description herein discusses that base station 400 is configured to perform or perform certain functions, but one or more of these functions may be performed by location server 172 and / or UE 300.

[0101] Memory 411 may store software 412 containing executable code or software instructions that, when executed by processor 410, enable processor 410 to operate as a dedicated computer programmed to perform the functions disclosed herein. As shown, memory 411 may include one or more elements or modules that can be implemented by processor 410 to perform the disclosed functions. Although elements or modules are shown as software 412 executable by processor 410 in memory 411, it should be understood that elements or modules may be stored in another computer-readable medium or may be dedicated hardware in or outside processor 410. Multiple software modules and data tables may reside in memory 411 and be used by processor 410 to manage both communications and the functions described herein simultaneously. It should be understood that the organization of the contents of memory 411 shown is merely exemplary, and the functions of modules and / or data structures may be combined, separated, and / or structured in different ways depending on the specific implementation.

[0102] For example, memory 411 may include an anchor UE selection communication period module 472, which, when implemented by processor 410, configures processor 410 to assist in selecting or down-selecting one or more anchor UEs for positioning. For example, one or more processors 410 may configure base station 400 to relay information between location server 172 and one or more candidate anchor UEs. Although the anchor UE selection communication period module 472 is described as software included in memory 411, the anchor UE selection communication period module 472 may be a hardware module, a software module, or a combination of hardware and software. For example, the module may include one or more application-specific integrated circuits (ASICs), executable code, or a combination of both.

[0103] Figure 5 illustrates server 500, an example of location server 172 capable of supporting location services in a wireless network (e.g., wireless network 100). Server 500 includes a computing platform comprising at least one processor 510, memory 511 including software (SW) 512, and transceiver 515. Processor 510, memory 511, and transceiver 515 may be communicatively coupled to each other via bus 520 (which may be configured for, for example, optical and / or electrical communication). One or more of the illustrated devices (e.g., wireless interfaces) may be omitted from server 500. Processor 510 may include one or more smart hardware devices, such as a central processing unit (CPU), microcontroller, application-specific integrated circuit (ASIC), etc. Processor 510 may include multiple processors (e.g., at least one of application processors, DSPs, modem processors, video processors, and / or sensor processors, similar to those shown in Figure 5). Memory 511 is a non-transitory storage medium that may include random access memory (RAM), flash memory, optical disk memory, and / or read-only memory (ROM). Memory 511 stores software 512, which may be processor-readable and processor-executable software code containing instructions configured, at execution, to cause processor 510 to operate as a dedicated computer program designed to perform the various functions described herein. Alternatively, software 512 may not be directly executable by processor 510, but may be configured to cause processor 510 to operate as a dedicated computer, for example, at compile and execution time, to perform the various functions described herein. This description may refer only to processor 510 performing a function, but it also includes other implementations, such as processor 510 performing software and / or firmware. This description may simply refer to processor 510 performing a function as processor 510 performing the function. This description may simply refer to server 500 performing a function as server 500 performing the function. In addition to and / or as a replacement for memory 511, processor 510 may include memory storing instructions.

[0104] Transceiver 515 may include one or both of a wireless transceiver 540 or a wired transceiver 550, which are configured to communicate with other devices via wireless and wired connections, respectively. For example, wireless transceiver 540 may include a transmitter 542 and a receiver 544 coupled to one or more antennas 546 for transmitting and / or receiving wireless signals 548 (e.g., on one or more downlink channels) and converting signals from wireless signals 548 into wired (e.g., electrical and / or optical) signals and from wired (e.g., electrical and / or optical) signals into wireless signals 548. Thus, transmitter 542 may include multiple transmitters that may be individual components or combined / integrated components, and / or receiver 544 may include multiple receivers that may be individual components or combined / integrated components. Wireless transceiver 540 can be configured to transmit signals according to various Radio Access Technologies (RATs) (e.g., with base station 400 (such as a gNB), one or more other base stations, UE 300, one or more other UEs, and / or one or more other devices), such RATs include 5G New Radio (NR), GSM (Global System for Mobile Communications), UMTS (Universal Mobile Telecommunications System), AMPS (Advanced Mobile Telephone System), CDMA (Code Division Multiple Access), WCDMA (Wideband CDMA), LTE (Long Term Evolution), LTE Direct (LTE-D), 6GPP LTE-V2X (PC5), IEEE 802.11 (including IEEE 802.11p), WiFi, WiFi Direct (WiFi-D), Bluetooth®, Zigbee, etc. Wired transceiver 550 may include a transmitter 552 and a receiver 554 configured for wired communications. Transmitter 552 may include multiple transmitters, which may be individual components or combined / integrated components, and / or receiver 554 may include multiple receivers, which may be individual components or combined / integrated components. Wired transceiver 550 may be configured for, for example, optical communication and / or electrical communication.

[0105] The configuration of server 500 shown in Figure 5 is an example and not a limitation thereof, including the request items, and other configurations may be used. For example, wireless transceiver 540 may be omitted. Alternatively or alternatively, the description herein discusses that server 500 is configured to perform or perform certain functions, but one or more of these functions may be performed by base station 400 and / or UE 300.

[0106] Memory 511 may store software 512 containing executable code or software instructions that, when executed by processor 510, enable processor 510 to operate as a dedicated computer programmed to perform the functions disclosed herein. As shown, memory 511 may include one or more elements or modules that can be implemented by processor 510 to perform the disclosed functions. Although elements or modules are shown as software 512 executable by processor 510 in memory 511, it should be understood that elements or modules may be stored in another computer-readable medium or may be dedicated hardware in or outside processor 510. Multiple software modules and data tables may reside in memory 511 and be used by processor 510 to manage both communications and the functions described herein simultaneously. It should be understood that the organization of the contents of memory 511 shown is merely exemplary, and the functions of modules and / or data structures may be combined, separated, and / or structured in different ways depending on the specific implementation.

[0107] For example, memory 511 may include an anchor UE selection communication period module 572, which, when implemented by processor 510, configures processor 510 to participate in supporting the selection or downselection of one or more anchor UEs for positioning, as discussed herein. Although the anchor UE selection communication period module 572 is described as software included in memory 511, the anchor UE selection communication period module 572 may be a hardware module, a software module, or a combination of hardware and software. For example, the module may include one or more application-specific integrated circuits (ASICs), executable code, or a combination of both.

[0108] For positioning, one or more anchor points are used as TRPs to transmit and / or receive PRS to / from the target UE. The distance between the TRP and the target UE can be based on the observed time difference of arrival (OTDOA) of one or more signals (referred to as OTDOA positioning) or any other suitable measurement used to determine the distance for positioning. OTDOA positioning is based on a multilateral positioning method, in which the UE typically measures the time of arrival (TOA) of a specific reference RF signal (e.g., PRS, CRS, CSI-RS, etc.) transmitted by different network node pairs (e.g., base station 102, base station 102's antenna, other UE 104, etc.). The reference signal time difference (RSTD) of the node pair can be determined by subtracting the TOA from the TOA from the reference node from several adjacent TOAs. As mentioned above, the time difference can be based on the reference signal (e.g., PRS) transmitted from the anchor to the UE, but the time difference can also be based on the round-trip time (RTT) of the signal from the UE to the anchor or from the anchor back to the anchor or adjacent device (in the case of the UE relaying PRS). The RSTD can be indicated to another device or otherwise used to determine the distance between the anchor and the UE. In some implementations, the anchor (and similar candidate anchors) or target UE can measure the RSTD between examples of PRS transmitted by other devices in the network. In some implementations, specific resources of the PRS can be used to measure the RSTD. As used herein, PRS resources can represent any appropriate portion or all of the PRS used for positioning.

[0109] Figure 6 illustrates an exemplary wireless communication system 600 that uses Time Difference of Arrival (TDOA) technology for positioning. In the example of Figure 6, UE 104 determines its estimated location or assists another entity (e.g., a base station or core network element, another UE, a location server, a third-party application, etc.) in determining its estimated location. UE 104 can wirelessly communicate with a plurality of base stations 102-1, 102-2, and 102-3 (collectively referred to as base stations 102) using RF signals and standardized protocols for RF signal modulation and information packet exchange. These base stations can correspond to any combination of base stations 102 in Figure 1. By extracting different types of information from the exchanged RF signals and utilizing the layout of the wireless communication system 600 (i.e., base station locations, geometry, etc.), UE 104 can determine its location in a predefined reference coordinate system or assist in its positioning decision. In one configuration, UE 104 can use a two-dimensional coordinate system to specify its location; however, the configurations disclosed herein are not limited to this, and a three-dimensional coordinate system can also be used to determine location if additional dimensions are required. Furthermore, although Figure 6 illustrates one UE 104 and three base stations 102, it should be understood that there can be more UEs 104 and more or fewer base stations 102 as anchors, or one or more anchors can be UEs 104 of the wireless network, as described herein. For example, any of base stations 102-1 to 102-3 can be replaced as an anchor UE for location.

[0110] Typically, RSTD is measured between a reference network node and one or more neighboring network nodes. In the example shown in Figure 6, base station 102-1 can be the serving base station of UE 104 and can further act as a reference base station, while base stations 102-2 and 102-3 act as neighboring base stations. For positioning using OTDOA, the reference network node remains the same for all RSTDs measured for UE 104 and typically corresponds to either the serving cell of UE 104 or another nearby cell with good signal strength at UE 104. In one case, when the measured network node is a cell supported by a base station, the neighboring network node is typically a cell supported by a base station different from the reference cell and may have good or poor signal strength at UE 104. RSTD can be the relative timing difference between two cells (e.g., a reference cell and a neighboring cell), which is determined based on the minimum time difference between the boundaries of two subframes from the two different cells.

[0111] Location calculation can be based on the time difference of measurements (e.g., RSTD) and the location of network nodes and relative transmission timing (e.g., knowledge about whether network nodes are accurately synchronized or whether each network node transmits with a known time difference relative to other network nodes).

[0112] To assist in the positioning operation, the location server 172 can provide the UE 104 with OTDOA auxiliary information for a reference network node (e.g., base station 102-1 in the example of FIG. 6 or an anchor UE in another example) and neighboring network nodes relative to the reference network node (e.g., base stations 102-2 and 102-3 in the example of FIG. 6 or one or more other anchors, which in another example may include anchor UEs). For example, the auxiliary information may include base station and reference signal (e.g., PRS) configuration information, and may provide the center channel frequency of each network node, various reference RF signal configuration parameters (e.g., number of consecutive positioning sub-frames, period of positioning sub-frames, silence sequence, frequency hopping sequence, reference RF signal ID, reference RF signal bandwidth), network node global ID, and / or other cell-related parameters applicable to OTDOA, as described above. The OTDOA auxiliary information may also indicate the serving cell of the UE 104 as the reference network node.

[0113] In one scenario, although the location server 172 can send auxiliary data to the UE 104, alternatively, the auxiliary data can originate directly from the network node (e.g., base station 102 or anchor UE) itself (e.g., in periodically broadcast management burden messages, etc.). Alternatively, the UE 104 can detect neighboring network nodes itself without using auxiliary data.

[0114] In the example of Figure 6, the measurement time difference between the reference cell of base station 102-1 and the adjacent cells of base stations 102-2 and 102-3 is represented as τ2-τ1 and τ3-τ1, where τ1, τ2, and τ3 represent the transmission time from one or more transmit antennas of base stations 102-1, 102-2, and 102-3 to the reference RF signal of UE 104, and include any measurement noise at UE 104. UE 104 can then convert TOA measurements from different network nodes into RSTD measurements (e.g., as defined in 3GPP TS36.214 under the heading "Physical layer; Measurements"). The location of UE 104 can be determined by using (i) RSTD measurements, (ii) the known absolute or relative transmission timing of each network node, (iii) the known location of one or more physical transmission antennas of the reference network node and adjacent network nodes, and / or (iv) directional reference signal characteristics such as transmission direction.

[0115] TOA T i at UE 104, the shortest path from base station i, is , where Di is the Euclidean distance between base station i with location (qi) and UE 104 with location (p), c is the speed of light in air (299700 km / s), and qi is obtained via a cellular information database (possibly contained in a location server or other network element). The Euclidean distance (i.e., the linear distance between two points) is provided by equation (1) below: (1)

[0116] Where D is the distance between two points on the Earth's surface, and R is the Earth's radius (6371 km). These are the latitudes (in radians) of the first point and the latitudes (in radians) of the second point, respectively. These are the longitudes (in radians) of the first point and the second point, respectively. If the anchor is a UE instead of a base station, the qi of the anchor UE may not be known. In this way, when the anchor is another UE, the position of the anchor UE must be determined in order to determine the position of UE 104 in Figure 6.

[0117] To identify the Time of Arrival (TOA) of a reference RF signal transmitted by a given network node, UE 104 first jointly processes all resource elements (REs) on the channel on which the network node (e.g., base station 102) is transmitting the reference RF signal and performs an inverse Fourier transform to convert the received RF signal to the time domain. Converting the received RF signal to the time domain is called Channel Energy Response (CER) estimation. The CER shows the peak values ​​on the channel over time, and therefore the earliest "significant" peak should correspond to the TOA of the reference RF signal. Typically, the UE will use a noise-related quality threshold to filter out spurious local peaks, thus potentially correctly identifying significant peaks on the channel. For example, UE 104 can select a TOA estimate that is the earliest local maximum value in the CER that is at least X dB higher than the median of the CER and a maximum Y dB lower than the dominant peak on the channel. UE 104 determines the CER for each reference RF signal from each network node in order to determine the TOA for each reference RF signal from different network nodes.

[0118] The TOA measurement performed by UE 104 relates to the geometric distance between UE 104 and the anchor (e.g., base station 102). In a two-dimensional Cartesian coordinate system, the (known) coordinates of the base station or the determined coordinates of the anchor UE can be represented as x 𝑖=[𝑥 𝑖,𝑦 𝑖] 𝑇 and the (unknown) coordinates of UE 104 can be represented as x 𝑡=[𝑥 𝑡,𝑦 𝑡] 𝑇. The RSTD measurement can be defined as the time difference (modulo 1-subframe (1-ms)) between two nodes (e.g., base stations), and therefore corresponds to the distance difference between the adjacent base station 102-i and the reference base station 102-1. The time difference between the adjacent base station 102-i and the reference base station 102-1 measured at UE 104 is given in the following equation (2): (2)

[0119] (TiT1) is the transmission time offset between base stations, called the "Real Time Difference" (RTD). The variables ni and n1 are the UE TOA measurement errors. The constant c is the speed of light.

[0120] At least two adjacent anchors (e.g., base stations) may be required to measure *i*, but more than two adjacent anchor measurements are desirable, and the system of equations can be solved in the least squares or weighted least squares sense. In a synchronous network, the transmission time offset (Ti-T1) should (ideally) be zero, and the equation above defines the TDOA. Geometrically, each TDOA defines a hyperbola, the width of which is determined by the TDOA error (ni-n1), as shown in Figure 6. If the coordinates of base station 102 and the transmission time offset (Ti-T1) are known at location server 172 or at UE 104, the location of UE 104 can be determined. Uncertainties in anchor coordinates or transmission time offsets will directly affect the accuracy of UE location estimation.

[0121] Location can be UE-assisted or UE-based. Using UE-assisted location, a server 500 (such as a location server 172) can determine the location / positioning of the target UE. Although the location server 172 is described as performing an operation for clarity, one or more other network entities in the wireless network can perform all or part of the described operation (e.g., base stations, core network elements, etc.). The location server 172 can also determine the RS resources to be used for location (such as a specific PRS format, frequency, time window, whether PRS transmission is triggered or periodic, etc.). The location server 172 can also select which base station 102 will be used as the TRP for location and the TRP settings (such as which UE will be supported). The location server 172 can indicate the determined resources to a base station 102 (such as a gNB), which can then indicate the resources to a UE 104 or use the indication to transmit the PRS. As described herein, one or more UEs 104 can be used as anchors for location. In some implementations, the location server 172 may downselect or select candidate anchor UEs to be used as anchor UEs for positioning. Downselection or selection may be based on preferences for anchor UEs from one or more target UEs. Alternatively, downselection or selection may be performed independently of any preferences from the target UEs. As described herein, downselection or selection may be based on one or more measurement qualities, one or more operational states, or one or more GDOPs. For UE-based positioning, the target UE may determine its location / positioning based on measurements of the PRS performed and provided by other devices and / or measurements of the PRS performed by the target UE (such as by RSTD as described above). The target UE (or the location server or another network entity) may downselect or select anchors for positioning (such as determining which PRS from which device or which measurement from which device is used for positioning). In some implementations, the target UE (or the location server or another network entity) may select or downselect candidate anchor UEs to be used as anchor UEs.

[0122] As mentioned above, one or more UEs can be used as anchors for positioning, where the anchor UE transmits and / or receives PRS via a side link (such as a PC5 connection) and otherwise communicates with the target UE via a side link. In this way, the anchor UE can operate as a TRP (similar to an anchor base station) for positioning. The accuracy of the target UE's position estimation based on one or more anchor UEs depends on the accuracy of the determined anchor UE's position. For example, referring back to equation (2) above, errors in the anchor UE's coordinates lead to errors in the estimated position of the target UE. The base station (such as a gNB) may be static, and its position is defined. However, UEs may move, and if a UE is to become an anchor UE, its positioning needs to be determined and used. Transmission strength or other factors may also differ for the anchor UE. The accuracy of the positioning of the candidate anchor UE or the suitability of the candidate anchor UE as an anchor can depend on the UE's movement, the UE's transmission strength, or other factors. For example, a faster-moving anchor UE may cause measurements (e.g., RSTD) associated with PRS to / from the anchor UE to become obsolete more quickly, or may be associated with higher Doppler effects or interference. The location determined for the anchor UE also needs to be updated and may have more errors or may be determined with lower accuracy (thus affecting the accuracy of the target UE's location estimation). In another instance, lower transmission power of the PRS at the anchor UE or interference with the PRS may result in a lower RSRP or SNR of the PRS, which may lead to difficulties or inaccuracies in processing the PRS to determine RSTD or other metrics. Alternatively, the anchor UE (and other anchors) can be associated with the GDOP based on the anchor UE's location and the positions of other anchors relative to the target UE. Anchor UEs associated with a smaller GDOP can be associated with a more accurate location determination for the target UE. Furthermore, moving anchor UEs cause changes in the GDOP, resulting in uncertainty in the accuracy of location estimation. The GDOP is described in more detail below with reference to Figure 9.

[0123] As described herein, one or more devices (such as one or more candidate anchor UEs, target UEs, or location servers) may perform operations to downselect or select candidate anchor UEs as anchor UEs for locating one or more target UEs. As described above and as used herein, downselection refers to filtering or excluding one or more candidates as anchors for the target UE. As noted herein, downselection (or selection in general) may be based on measurement metrics from one or more candidate anchor UEs (such as RSRP or SNR of PRS or another signal), the operational status of one or more candidate anchor UEs (such as based on IMU measurements, GNSS measurements, and / or location estimates of candidate anchor UEs), or GDOP associated with different combinations of candidate anchor UEs with other candidate anchor UEs and / or base stations. Selection (such as downselection) or other operations may be performed by one or more of the location server, candidate anchor UE, target UE, another UE, base station (such as gNB), or another suitable network entity of the radio network. Because the measurement quality of the positioning measurements of the candidate anchor UE, the operational status of the candidate anchor UE, or the GDOP associated with the candidate anchor UE may change over time, one or more devices may repeatedly operate or otherwise adjust (such as periodically or based on triggers) which device is used as the anchor for positioning. Exemplary operations in selecting or down-selecting candidate anchor UEs or otherwise associated with positioning are described in more detail below.

[0124] Figure 7 illustrates a flowchart of an exemplary method 700 for selecting an anchor UE for locating a target UE in a wireless network. As used herein, selecting an anchor UE may refer to selecting candidate anchor UEs as anchor UEs, or alternatively, to selecting one or more candidate anchor UEs downward from those used as anchor UEs, or otherwise reducing the number of candidate anchor UEs. For example, a subset of candidate anchor UEs may be selected to retain potential anchor UEs, while unselected candidate anchor UEs may be excluded from consideration. The exemplary method 700 may be performed by any suitable device in the wireless network, such as the target UE 104 or location server 172 shown in Figure 1, in a manner consistent with the disclosed implementation. For example, method 700 may be performed by the target UE 104 for UE-based localization, or by the location server 172 for UE-assisted localization. A device capable of performing one or more operations in method 700 (or any other described method, such as method 800 in FIG. 8 or method 1000 in FIG. 10) may include at least one transceiver (such as one or more wireless transceivers and / or one or more wired transceivers), at least one memory, and at least one processor coupled to at least one transceiver and at least one memory. Referring to UE 300 as an exemplary device, at least one transceiver may include transceiver 315 or wireless transceiver 340, at least one memory may include memory 311, and at least one processor may include one or more of the following: processor 310, one or more of processors 330-334, or positioning device 319. Referring to base station 400 as an exemplary device, at least one transceiver may include all or part of transceiver 415, at least one memory may include memory 411, and at least one processor may include processor 410. Referring to server 500 (e.g., location server) as an exemplary device, at least one transceiver may include all or part of transceiver 515, at least one memory may include memory 511, and at least one processor may include processor 510.

[0125] In block 702, the device obtains one or more positioning measurements of the candidate anchor UE and a measurement quality metric for each of the positioning measurements from one or more candidate anchor UEs among a plurality of candidate anchor UEs. The components used to obtain the one or more positioning measurements and the measurement quality metric for each of the positioning measurements may include at least one transceiver of the device. As mentioned above, if the UE is used as an anchor for positioning, the position / location of the anchor UE is required because the position estimation of the target UE is based on the positioning of the anchor used for positioning. Candidate anchor UEs may generate (or one or more other devices may determine) positioning measurements of the candidate anchor UEs. Positioning measurements may include estimates of the positioning of the candidate anchor UEs or measurements (such as one or more RSTDs) that can be used to determine / estimate the positioning of the candidate anchor UEs.

[0126] In some implementations, the candidate anchor UE can generate location measurements independent of Radio Access Technology (RAT). In this way, the location measurements and measurement quality are not associated with the radio network (such as radio network 100 for UE 104). For example, the location measurements and measurement quality metrics can be based on GPS or other GNSS. A GNSS receiver, independent of radio transceivers associated with one or more RATs, can be used to determine the location of the candidate anchor UE. Alternatively, the location can be determined or adjusted based on measurements from an IMU or other sensors. In some other implementations, the location measurements can be RAT-dependent. For example, the location measurements can include RSTDs obtained by the candidate anchor UE using PRS resource measurements from one or more devices in the radio network (such as one or more base stations 102 for UE-assisted positioning or the target UE 104 for UE-based positioning). As mentioned above, RSTDs can be used to determine the location of the device based on the location of the transmitting PRS(one or more) devices. For example, the candidate anchor UE can measure RSTD based on three base stations within the candidate anchor UE's range, thereby determining the location of the candidate anchor UE.

[0127] Measurement quality metrics for positioning measurements can be associated with the accuracy of estimating or estimating the positioning / location for a candidate anchor UE. For example, if the positioning measurement is a location determined at the UE using a GNSS receiver (such as SPS receiver 317), the measurement quality metric can be associated with the tolerance (potential error) of the estimated location. For example, the receiver can be associated with a potential error in inches or meters, and the estimated location of the UE can differ from the actual location by a maximum of the potential error. The magnitude of the potential error can be based on the number of positioning satellites coupled to the receiver (as the number of satellites increases, the accuracy of the estimated location increases) or the resolution of the satellites (such as timing indication from positioning satellites with higher resolution, which can improve the accuracy of the estimated location). Exemplary measurement quality metrics for positioning measurements associated with positioning satellites can include the number of positioning satellites used, timing resolution, or positioning satellite position resolution, or other suitable metrics. In some implementations, measurement quality can include indication of using GNSS-based positioning instead of land-based positioning (where GNSS-based positioning can be more accurate than land-based positioning).

[0128] If one or more location measurements include one or more RSTDs (or locations determined by RSTDs) obtained by a candidate anchor UE using PRS resource measurements from a device in the radio network, then measurement quality metrics may be associated with the quality that may affect the determination of the RSTD. Exemplary measurement quality metrics may include the RSRP of the obtained PRS, the SNR of the obtained PRS, or other suitable indications associated with the power or quality of the RS. Measurement quality metrics may additionally or alternatively be associated with the accuracy of the location that can be determined by the RSTD. For example, based on the timing of the PRS, the resolution of the timing of the indicated or measured PRS, or other factors, the first RSTD may be associated with a larger tolerance (potential error) for any location determination compared to a second RSTD. Exemplary measurement quality metrics may include the timing of the PRS or the resolution of the timing of the measured or indicated PRS.

[0129] One or more location measurements and associated measurement quality metrics may be included in one or more location measurement reports. For example, a candidate anchor UE may provide a location measurement report that includes location measurements and measurement quality metrics. For UE-assisted positioning, the report may be provided to the location server 172 (via base station 102 (and optionally relaying the UE) and core network 170). For UE-based positioning, the report may be provided to the target UE. In some implementations, the device performing the operation of method 700 may obtain one or more location measurements and measurement quality metrics from one or more NR-based location measurement reports from the candidate anchor UE. For example, an NR-based location measurement report may include an NR location measurement report of a UE configured to include measurement quality metrics (such as those defined in Release 16 of the 3GPP standards set associated with 5G NR).

[0130] For UE-based positioning, the device performing method 700 can be the target UE, and the target UE obtains a positioning measurement report from the candidate anchor UE via a side link between the target UE and the candidate anchor UE. The PRS resources obtained by the candidate anchor UE for determining the positioning measurements and measurement quality metrics in the positioning measurement report can be transmitted by the target UE. In this manner, the candidate anchor UE determines the measurements and metrics based on the PRS obtained via the side link with the target UE and provides the positioning measurement report to the target UE via the side link.

[0131] For UE-assisted positioning, the device performing method 700 can be a location server. If the positioning measurement report is NR-based, the gNB can provide one or more PRS resources to candidate anchor UEs on the downlink, and the candidate anchor UEs can provide positioning measurement reports to the gNB on the uplink. The gNB can provide positioning measurements and measurement quality metrics from the reports to the location server. In this way, the location server can obtain positioning measurements and measurement quality metrics for a plurality of candidate anchor UEs.

[0132] In block 704, the device can select at least one candidate anchor UE from a plurality of candidate anchor UEs for positioning the target UE based on one or more measurement quality metrics from one or more candidate anchor UEs. In some embodiments, the device can select a plurality of candidate anchor UEs downward for positioning the target UE based on one or more measurement quality metrics from one or more candidate anchor UEs, thereby still including at least one candidate anchor UE. In this way, one or more candidate anchor UEs can be excluded from consideration as anchors. In some embodiments, the device can select at least one candidate anchor UE as the anchor of the target UE. The components for selecting or downward selecting a plurality of candidate anchor UEs from a plurality of candidate anchor UEs may include at least one processor of the device. In some embodiments, selecting or downward selecting a plurality of candidate anchor UEs may include limiting the number of candidate anchor UEs (or the total number of candidate anchors) to a maximum number. For example, if the number of candidate anchors is limited to four and the measurement quality metric is timing resolution, the device can exclude one or more candidate anchors among the candidate anchors whose measured timing resolution is less than the first four timing resolutions. In some implementations, selecting or downselecting a plurality of candidate anchor UEs may include excluding one or more candidate anchor UEs based on one or more measurement quality thresholds. For example, if the timing resolution of a measurement from the UE is less than a timing resolution threshold, the device may exclude a candidate anchor UE. In some implementations, selecting or downselecting a plurality of candidate anchor UEs may include excluding one or more candidate anchor UEs based on the variability of a measurement quality metric. The device may obtain a measurement quality metric for each of the plurality of candidate anchor UEs, the device may determine the variability of the measurement quality metric, and the device may exclude candidate anchor UEs based on a comparison of the measurement quality metric associated with the UE with the variability. For example, the device may determine the mean and variance of the measurement quality metric. Although mean and variance are described, other measurement distributions of the measurement quality metric, such as parametric distributions, including median, standard deviation, quantiles, etc., may be used. After determining the mean and variance, selection or downselection may be based on the measurement quality metric within multiple variances of the mean. For example, any candidate anchor UE associated with a measurement quality metric less than the mean minus the variance can be excluded from use as an anchor UE for positioning. It should be noted that excluding a candidate anchor UE can be for one or more target UEs. In some implementations, a candidate anchor UE can still be used as an anchor for one or more other UEs in the wireless network. Therefore, excluding a candidate anchor UE for positioning a target UE does not require excluding the candidate anchor UE from all anchors used for positioning any and all UEs in the wireless network. Additionally, as noted herein, the term selection can refer to selecting, excluding, or selecting at least one candidate anchor UE.

[0133] Since the anchor UE transmits to or receives from the target UE via a sidelink, the link quality of the sidelink can also affect the positioning of the target UE. For example, a noisy sidelink may prevent PRS from being received or decoded. Selection can be based on the link quality of the sidelink between the target UE and the candidate anchor UE. The candidate anchor UE or the target UE can determine the link quality metrics of the sidelink (such as SINR, SNR, RSRP, etc.) and can take these metrics into account in the selection. For example, if the SNR of the sidelink is less than an SNR threshold, the candidate anchor UE can be excluded. Selection using link quality metrics can be performed in any suitable manner, such as any of the methods described above regarding measurement quality metrics.

[0134] If the device selects a candidate anchor UE for positioning, the device can indicate the selection to the anchor UE, and the anchor UE can be configured to transmit a PRS to or receive a PRS from the target UE. For example, for UE-assisted positioning, the location server 172 can indicate the selection to one or more base stations (e.g., gNBs), and the base stations (e.g., gNBs) can indicate the selection to the appropriate UE to be used as the anchor. This indication can also be provided to the target UE. For UE-based positioning, the target UE can indicate the selection to each anchor UE via its respective side link.

[0135] Although method 700 is described as an example of selection or down-selection for clarity, the device can be configured to perform selection or down-selection multiple times. For example, candidate anchor UEs can periodically provide location measurement reports. If the anchor UE's location measurement changes beyond a threshold, the measurement quality metric changes beyond a threshold (or no longer meets the initial selection criteria for selecting the anchor UE), or the link quality metric changes beyond or below a threshold, the device can again down-select candidate anchor UEs or select an anchor UE for positioning. In this way, which anchor UE is used for positioning can be adjusted over time.

[0136] As mentioned above, method 700 in Figure 7 refers to the positioning measurements of the candidate anchor UEs (the accuracy of the anchor UE's determined position affects the accuracy of the target UE's determined position). Alternatively, the choice of which anchor UE to use may be based on the action state of each candidate anchor UE, as described below with reference to Figure 8.

[0137] Figure 8 illustrates a flowchart of an exemplary method 800 for selecting an anchor UE for locating a target UE in a wireless network. The exemplary method 800 can be performed by any suitable device in the wireless network (such as the target UE 104 or location server 172 shown in Figure 1) in a manner consistent with the specific implementation disclosed. For example, method 800 can be performed by the target UE 104 for UE-based positioning, or by the location server 172 for UE-assisted positioning. Devices that can perform one or more operations in method 800 may include at least one transceiver (such as one or more wireless transceivers and / or one or more wired transceivers), at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. Referring to UE 300 as an exemplary device, the at least one transceiver may include transceiver 315 or wireless transceiver 340, the at least one memory may include memory 311, and the at least one processor may include one or more of the following: processor 310, one or more of processors 330-334, or positioning device 319. Referring to base station 400 as an exemplary device, at least one transceiver may include all or part of transceiver 415, at least one memory may include memory 411, and at least one processor may include processor 410. Referring to server 500 (e.g., location server) as an exemplary device, at least one transceiver may include all or part of transceiver 515, at least one memory may include memory 511, and at least one processor may include processor 510.

[0138] In block 802, the device obtains the action state of one or more candidate anchor UEs from a plurality of candidate anchor UEs. The components used to obtain the action state may include one or more of the device's at least one transceiver, at least one memory, or at least one processor. In some embodiments, obtaining the action state of a candidate anchor UE means that the candidate anchor UE determines its action state and the device obtains that action state from the candidate anchor UE. The candidate anchor UE may determine its action state using a method independent of RAT. For example, the candidate anchor UE may use IMU measurements (such as accelerometer or other sensor measurements) to determine its movement. In another instance, the candidate anchor UE may determine its movement based on GNSS measurements to determine the difference in its position over time. This movement may be a rate, velocity, acceleration, displacement, or other indication of the candidate anchor UE's action. Alternatively or concurrently, the candidate anchor UE may use a RAT-related method to determine its action state. For example, the candidate anchor UE may use RSTD (such as described above) at different times to determine its position, and the candidate anchor UE may determine its movement based on the difference in position over time. This movement can be a rate, velocity, acceleration, displacement, Doppler shift, or other indication of the candidate anchor UE's action. Action status can be provided in any suitable manner, such as in NR-based positioning measurement reports from the candidate anchor UE to the target UE or location server. For example, for UE-based positioning, the target UE can obtain action status from the candidate anchor UE via a side link between the target UE and the candidate anchor UE.

[0139] In some implementations of obtaining the operational status, the device itself determines the operational status of the candidate anchor UE. For example, the device can determine the operational status of the candidate anchor UE based on its positioning history. For UE-assisted positioning, the location server 172 can perform the operations of method 800. In this way, the location server 172 can determine the operational status of the candidate anchor UE based on its positioning history. In some implementations, the location server 172 may include a database of one or more UEs' positioning data. Positioning can be determined based on the RSTD obtained for the UE (e.g., as described above), where the UE or other device provides a positioning measurement report including the RSTD. In this way, the location server 172 can determine the positioning history. The location server 172 can use the UE's positioning (and optionally the time of positioning) to determine the UE's movement (which may include speed, rate, acceleration, displacement, etc.). For UE-based positioning, the positioning measurement report can be provided to the target UE, and the target UE can determine the positioning history of the candidate anchor UE over time.

[0140] In block 804, the device can select at least one candidate anchor UE from a plurality of candidate anchor UEs for positioning a target UE based on one or more action states. In some embodiments, the device can select a plurality of candidate anchor UEs downwards for positioning a target UE based on one or more action states. The component for selecting at least one candidate anchor UE (such as selecting a plurality of candidate anchor UEs downwards) may include at least one processor of the device. In some embodiments, selecting or downwards selecting a plurality of candidate anchor UEs may include excluding one or more candidate anchor UEs based on one or more action state thresholds. For example, if the speed of the UE is greater than a speed threshold, the device may exclude the candidate anchor UE. In some embodiments, selecting or downwards selecting a plurality of candidate anchor UEs may include excluding one or more candidate anchor UEs based on the variability of action states. For example, the device may determine that the action state of a candidate anchor UE fluctuates more than a threshold number of times within a certain time period (such as changes in speed, displacement, etc. over time), which may indicate a change in the movement of the candidate anchor UE. The device may exclude the use of a candidate anchor UE based on the number of fluctuations exceeding a threshold number.

[0141] Similar to the description above with reference to Figure 7, because the anchor UE transmits to or receives from the target UE via a side link, the link quality of the side link can also affect the positioning of the target UE. For example, a noisy side link may prevent PRS from being received or decoded. Selection can be based on the link quality of the side link between the target UE and the candidate anchor UE. The candidate anchor UE or the target UE can determine the link quality metrics of the side link (such as SINR, SNR, RSRP, etc.) and can take these metrics into account for selection. For example, if the SNR of the side link is less than the SNR threshold, the candidate anchor UE can be excluded. Selection using link quality metrics can be performed in any suitable manner, such as any of the methods described above regarding measurement quality metrics or action states.

[0142] In some implementations, if the device selects a candidate anchor UE for positioning, the device can indicate the selection to the anchor UE, and the anchor UE can be configured to transmit a PRS to or receive a PRS from the target UE. For example, for UE-assisted positioning, the location server 172 can indicate the selection to one or more base stations (e.g., gNBs), and the base stations (e.g., gNBs) can indicate the selection to the appropriate UE to be used as the anchor. This indication can also be provided to the target UE. For UE-based positioning, the target UE can indicate the selection to each anchor UE via its respective sidelink.

[0143] Although method 800 is described as an example of selection or down-selection for clarity in describing the various aspects of this case, the device can be configured to perform selection or down-selection multiple times. For example, an anchor UE may have movement less than a threshold before time Q, but may have movement greater than the threshold after time Q. Therefore, the anchor UE may no longer be suitable for positioning. In some embodiments, candidate anchor UEs may periodically provide their action status to the device. In this way, the device can periodically decide whether a candidate anchor UE should remain an anchor UE or remain excluded from being an anchor UE (e.g., based on one or more thresholds, variability, etc. as described above), and decide which anchor UE can be used over time. In some embodiments, the provision of action status by candidate anchor UEs is trigger-based. For example, if the action status is greater than an action threshold (e.g., speed is greater than a speed threshold), the candidate anchor UE can provide the action status to the device. In this way, when the action status has not changed by more than a threshold since the last report, the candidate anchor UE can save power by not reporting the action status to the device. While the above describes reporting action status periodically or on a trigger-based basis, providing action status can also refer to location measurements or other information (such as RSTD) provided by candidate anchor UEs, where the device determines the action status of the candidate anchor UE itself based on the location measurements or other information. Alternatively, candidate anchor UEs can indicate that a link quality metric has changed greater than a threshold or that a link quality metric has become less than a threshold. Based on changes in action status and / or link quality metric changes, the device can again select candidate anchor UEs or select an anchor UE for positioning. In this way, which anchor UE is used for positioning can be adjusted over time.

[0144] As mentioned above, method 700 in Figure 7 refers to the positioning measurements of the candidate anchor UE, and method 800 in Figure 8 refers to the operational state of the candidate anchor UE. Alternatively, the anchor UE to be used to locate the target UE can be based on the GDOP associated with the candidate anchor UE.

[0145] In positioning, the geometry of the target UE and the TRP (Tracking Point Representation Platform) can affect the accuracy or potential error of the target UE's location estimation. For example, based on the PRS resolution and timing, the UE's location may be within a certain distance range from the TRP. For multiple TRPs, the UE's location may lie within the intersection of the distance ranges of the multiple TRPs. The intersection of these ranges represents the positioning uncertainty of the UE when using multiple TRPs for positioning. Adjusting the TRP's position can adjust the shape and magnitude of the positioning uncertainty, which may affect the accuracy of determining the UE's positioning.

[0146] Figure 9A is a diagram 900 illustrating the location uncertainty 910A of a UE associated with two TRPs 902 and 904 used for positioning. Based on the timing and resolution of the PRS, the UE's location can be determined to be within the range 906 of TRP 902. Similarly, based on the timing and resolution of the PRS, the UE's location can be determined to be within the range 908 of TRP 904. In this way, the UE can be located within the intersection of the two ranges 906 and 908, which is indicated as location uncertainty 910A. The positions of TRPs 902 and 904 affect the size and magnitude of location uncertainty 910A. Furthermore, although not illustrated, the number of TRPs used may affect the size and magnitude of location uncertainty 910A.

[0147] Figure 9B is a diagram of Figure 901 illustrating the location uncertainty 910B of the UE associated with the two TRPs 902 and 904 used for positioning. Compared to Figure 900, the positions of TRPs 902 and 904 relative to each other are different. Therefore, ranges 906 and 908 in Figure 901 are associated with the location uncertainty 910B. The magnitude of the location uncertainty 910B is greater than that of the location uncertainty 910A, where the UE is located somewhere within the corresponding location uncertainty. Therefore, the potential error in the UE's location estimation is larger in the TRP topology of Figure 901 than in Figure 900. The intersection of ranges (such as location uncertainties 910A or 910B) may be referred to herein as GDOP. GDOP can be calculated in any suitable manner based on the type of positioning method used (such as TOA-based positioning).

[0148] In some implementations, a set of candidate anchor UEs can be selected or down-selected based on the GDOP associated with one or more candidate anchor UEs. For example, some candidate anchor UEs can be excluded as anchors, or some candidate anchor UEs can be selected as anchors to reduce the size of the GDOP, which can improve the accuracy or precision of the target UE's location estimation.

[0149] Figure 10 illustrates a flowchart of an exemplary method 1000 for selecting an anchor UE for locating a target UE in a wireless network. The exemplary method 1000 can be performed by any suitable device in the wireless network (such as the target UE 104 or location server 172 shown in Figure 1) in a manner consistent with the specific implementation disclosed. For example, method 1000 can be performed by the target UE 104 for UE-based positioning, or by the location server 172 for UE-assisted positioning. Devices that can perform one or more operations in method 1000 may include at least one transceiver (such as one or more wireless transceivers and / or one or more wired transceivers), at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. Referring to UE 300 as an exemplary device, the at least one transceiver may include transceiver 315 or wireless transceiver 340, the at least one memory may include memory 311, and the at least one processor may include one or more of the following: processor 310, one or more of processors 330-334, or positioning device 319. Referring to base station 400 as an exemplary device, at least one transceiver may include all or part of transceiver 415, at least one memory may include memory 411, and at least one processor may include processor 410. Referring to server 500 (e.g., location server) as an exemplary device, at least one transceiver may include all or part of transceiver 515, at least one memory may include memory 511, and at least one processor may include processor 510.

[0150] In block 1002, the device can obtain information associated with a plurality of GDOPs, where each GDOP is determined for a different combination of candidate anchor UEs from a plurality of candidate anchor UEs for the target UE. The components used to obtain the information may include at least one transceiver of the device. In some embodiments, the target UE can determine each GDOP. For example, a plurality of candidate anchor UEs are in range and capable of communicating with the target UE via sidelinks. The target UE can select a first subset of candidate anchor UEs and estimate a first GDOP for the first subset, select a second subset of candidate anchor UEs and estimate a second GDOP for the second subset, and so on. Any suitable number of candidate anchor UEs (such as three or more) can be selected for each subset, and any suitable number of subsets can be selected. For example, the target UE can limit the number of subsets and / or the number of UEs to a minimum and / or maximum number to balance the processing resources and time when estimating GDOPs with the optimal subset of candidate anchor UEs (such as the subset associated with the minimum GDOP) that can be identified for locating the target UE.

[0151] The decision (e.g., estimation) of GDOP can be performed in any suitable manner. For example, the target UE can use any known statistical method to estimate the GDOP. Alternatively, the target UE can use one or more machine learning models to estimate the GDOP. The inputs to one or more machine learning models may include RSTD measured by the candidate anchor UE, other location measurements of the candidate anchor UE, signal quality metrics, operational status, etc. In some implementations, data from the base station can be used as training data to train the machine learning model to estimate the GDOP. The location of the base station is known and can be used to determine the known GDOP associated with different subsets of the base station. The known GDOP can be compared with the estimated GDOP as feedback for training the machine learning model. By training the machine learning model, such models can be used to estimate the GDOP of subsets of candidate anchor UEs whose locations may not be known or less precise than the known locations of the base station. Although the above examples describe the target UE as determining the GDOP for clarity in describing the various scenarios in this case, any suitable device can determine one or more GDOPs (e.g., base station, neighboring UE, candidate anchor UE, or another suitable network entity).

[0152] At 1004, the device can select one or more anchor UEs from a plurality of candidate anchor UEs for positioning a target UE. The component used to select one or more anchor UEs may include at least one processor of the device. This selection is based on information associated with a plurality of GDOPs. As described above, the target UE can determine the GDOPs of different subsets of the candidate anchor UEs. For UE-based positioning, the target UE can select an anchor UE from the candidate anchor UEs based on the determined GDOPs. In this way, the information associated with the plurality of GDOPs can be the GDOPs themselves. For example, the target UE can compare GDOPs to determine a minimum GDOP, and the target UE can select the candidate anchor UE with the minimum GDOP as the anchor UE for positioning.

[0153] For UE-assisted positioning, location server 172 can select an anchor UE from candidate anchor UEs. In some implementations, the information associated with a plurality of GDOPs can be the GDOPs themselves. In this way, a plurality of GDOPs (such as those from the target UE) can be provided to a base station (e.g., gNB) or a relay UE between the target UE and the base station (e.g., gNB), and the GDOPs can be relayed to location server 172 (e.g., via gNB and / or core network 170). Indicating a GDOP can include indicating the candidate anchor UEs associated with each GDOP. In this way, location server 172 can obtain GDOPs from the base station, and location server 172 can select one or more anchor UEs from the candidate anchor UEs based on the plurality of GDOPs obtained from the base station.

[0154] The target UE can indicate all or only a portion of the GDOPs and associated candidate anchor UEs determined by the target UE. For example, the target UE can exclude GDOPs larger than a threshold size. In another instance, the target UE can exclude GDOPs associated with a specific candidate anchor UE (such as measurement quality based on positioning measurements or the operational status of the candidate anchor UE). In this way, the target UE can select candidate anchor UEs from the group before the location server 172 selects candidate anchor UEs from this group.

[0155] Alternatively, as an alternative to indicating a GDOP, the target UE can determine one or more preferred anchor UEs from a plurality of candidate anchor UEs based on a plurality of GDOPs, and the target UE can indicate the one or more preferred anchor UEs. In this way, the information associated with a plurality of GDOPs can include the indication of one or more preferred anchor UEs. For example, the target UE can determine one or more preferred anchor UEs as one or more candidate anchor UEs associated with a specific GDOP (such as one or more minimum GDOPs estimated by the target UE) or a GDOP smaller than a threshold GDOP size. If a preferred anchor UE is indicated for each GDOP instead of the GDOP and the associated candidate anchor UEs, the indication can reduce signaling requirements compared to indicating the GDOP. The target UE can indicate one or more preferred anchor UEs to a base station serving the target UE or a relay UE between the base station and the target UE (the indication is provided to the base station), and the location server 172 can obtain the indication of one or more preferred anchor UEs from the base station (e.g., via the core network 170). In some implementations, the indication may include an indication of the sorting or order of preferred anchor UEs. The location server 172 may select one or more anchor UEs based on the indications of one or more preferred anchor UEs.

[0156] Although method 1000 has been described above with reference to a single target UE, selecting an anchor UE for locating a target UE can be based on selecting an anchor UE for locating one or more UEs other than the target UE. Location server 172 can support UE-assisted location for a plurality of target UEs. In this way, TRP can be used to locate multiple target UEs. If location server 172 determines the anchor UE for each target UE without referring to anchor UEs determined for other target UEs, a large number of UEs can be selected as anchors, thus reducing the resource consumption of more UEs acting as TRPs for location compared to what might be necessary or desirable. Selecting an anchor UE for a first target UE can consider selecting an anchor UE for a second or other target UE. For example, if location server 172 receives an indication of a better anchor UE for a target UE, location server 172 can compare the better anchor UEs among multiple target UEs to determine a subset of anchor UEs, thereby supporting location for all target UEs. Although a better anchor UE can be indicated for a target UE, it can also be excluded if it is not a better anchor UE for other target UEs. Although some examples have been provided above to describe some aspects of this case, any suitable method can be used to determine which anchor UE to use for locating multiple target UEs.

[0157] Similar to the descriptions above with reference to Figures 7 and 8, because the anchor UE transmits to or receives from the target UE via a sidelink, the link quality of the sidelink can also affect the positioning of the target UE. For example, a noisy sidelink may prevent PRS from being received or decoded. The selection of the anchor UE can be based on the link quality of the sidelink between the target UE and the candidate anchor UE. The candidate anchor UE or the target UE can determine the link quality metrics of the sidelink (such as SINR, SNR, RSRP, etc.) and can consider the link quality metrics of the sidelink for downlink selection or selection. For example, if the SNR of the sidelink is less than the SNR threshold, the candidate anchor UE can be excluded. Downlink selection or selection using link quality metrics can be performed in any suitable manner, such as any of the methods described above regarding measurement quality metrics, action status, or GDOP.

[0158] In some implementations, the device can indicate the selection to a selected anchor UE, and the anchor UE can be configured to transmit a PRS to or receive a PRS from the target UE. For example, for UE-assisted positioning, the location server 172 can indicate the selection to one or more base stations (e.g., gNBs), and the base stations (e.g., gNBs) can indicate the selection to appropriate UEs to be used as anchors. This indication can also be provided to the target UE. For UE-based positioning, the target UE can indicate the selection to each anchor UE via its respective side link.

[0159] Although method 1000 is described as an example of selecting one or more anchor UEs for clarity in describing the various aspects of this case, the device can be configured to perform the selection multiple times. For example, the GDOP can change based on the movement of the anchor UE. The location server or target UE (or another suitable device) can decide to change the GDOP based on periodically estimating the GDOP over time (such as based on new positioning measurements or other inputs from the anchor UE) or based on triggers associated with the anchor UE's positioning measurements or movement state. Therefore, the anchor UE may no longer be suitable for positioning the target UE. In this way, the device can periodically decide whether candidate anchor UEs should remain anchor UEs or remain excluded from anchor UEs (such as based on one or more thresholds, variability, etc. as described above), and decide which anchor UEs can be adjusted over time. For example, a new GDOP can be determined, and one or more new anchor UEs can be selected for positioning based on information associated with the new GDOP. Alternatively, for UE-assisted positioning, if the number of target UEs or the target UEs themselves change, the location server can again execute method 1000 to select one or more anchor UEs. The selection of one or more anchor UEs can be periodic or based on triggering in any suitable manner.

[0160] Methods 700, 800, and 1000 in Figures 7, 8, and 10 respectively describe selection or downselection based on measurement quality, operational status, or GDOP of mutually independent location measurements. However, selection or downselection can be based on any combination of measurement quality, operational status, or GDOP of location measurements (or optionally, link quality metrics of sidelinks). In this way, one or more devices of the wireless network (such as location server 172 or target UE) can perform one or more operations of one or more methods in methods 700, 800, or 1000. For example, selection of an anchor UE can be based on the operational status of a candidate anchor UE and the GDOP associated with the candidate anchor UE, and downselection of a candidate anchor UE can be based on the measurement quality metric of the candidate anchor UE's location measurement and the candidate anchor UE's operational status, etc.

[0161] Figure 11 illustrates a flowchart of an exemplary method for selecting an anchor UE for locating a target UE in a wireless network. Exemplary method 1100 can be performed by any suitable device in the wireless network (such as the target UE 104 or location server 172 shown in Figure 1) in a manner consistent with the specific implementation disclosed. For example, method 1100 can be performed by the target UE 104 for UE-based positioning, or by the location server 172 for UE-assisted positioning. Devices that can perform one or more operations in method 1100 may include at least one transceiver (such as one or more wireless transceivers and / or one or more wired transceivers), at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. Referring to UE 300 as an exemplary device, at least one transceiver may include transceiver 315 or wireless transceiver 340, at least one memory may include memory 311, and at least one processor may include one or more of the following: processor 310, one or more of processors 330-334, or positioning device 319. Referring to base station 400 as an exemplary device, at least one transceiver may include all or part of transceiver 415, at least one memory may include memory 411, and at least one processor may include processor 410. Referring to server 500 (e.g., location server) as an exemplary device, at least one transceiver may include all or part of transceiver 515, at least one memory may include memory 511, and at least one processor may include processor 510.

[0162] At 1102, the device obtains information associated with one or more of the following: positioning measurements and measurement quality metrics from one or more candidate anchor UEs; the operational status of one or more candidate anchor UEs; or GDOPs associated with one or more candidate anchor UEs. The components used to obtain the information may include one or more of the following: at least one transceiver, at least one memory, or at least one processor of the device. As described above, selecting at least one candidate anchor UE may be based on positioning measurements and measurement quality metrics associated with the candidate anchor UE (such as those described above with reference to FIG. 7), the operational status of the candidate anchor UE (such as those described above with reference to FIG. 8), information associated with different combinations of GDOPs of candidate anchor UEs for the target UE (such as those described above with reference to FIG. 10), or any combination thereof. In this manner, the device may perform one or more of optional steps 1104-1108 to perform step 1102.

[0163] In some embodiments, the device may obtain a measurement quality metric (1104) of one or more positioning measurements of a candidate anchor UE and each of the positioning measurements from one or more candidate anchor UEs among a plurality of candidate anchor UEs. The components used to obtain the measurement quality metric of each of the one or more positioning measurements may include at least one transceiver of the device. Optionally, step 1104 may be the same as step 702 in FIG. 7 above.

[0164] In some implementations, the device can obtain the operational status of one or more candidate anchor UEs from a plurality of candidate anchor UEs (1106). The components used to obtain the operational status may include one or more of the following: at least one transceiver, at least one memory, or at least one processor of the device. Optionally, step 1106 may be the same as step 802 in FIG8 above.

[0165] In some implementations, the device may obtain information associated with a plurality of GDOPs, wherein each GDOP is determined for a different combination of candidate anchor UEs for the target UE from a plurality of candidate anchor UEs (1108). The components for obtaining the information may include at least one transceiver of the device. Optionally, step 1108 may be the same as step 1002 in FIG10 above.

[0166] At step 1110, the device selects at least one candidate anchor UE from a plurality of candidate anchor UEs for positioning the target UE based on the acquired information. The component used to select at least one candidate anchor UE may include at least one processor of the device. For example, the location server or at least one processor of the target UE may be configured to select at least one candidate anchor UE based on one or more positioning measurements and measurement quality metrics of the acquired candidate anchor UEs, the operational status of the acquired candidate anchor UEs, or one or more of the information associated with a plurality of GDOPs for different combinations of candidate anchor UEs for the target UE (such as selecting a plurality of candidate anchor UEs downwards or selecting one or more candidate anchor UEs as anchors). To perform step 1110, the device may perform some or all of the operations described herein for one or more of steps 704 in FIG. 7, 804 in FIG. 8, or 1004 in FIG. 10.

[0167] Throughout this specification, references to "an example," "an instance," "some instances," or "exemplary implementation" mean that a particular feature, structure, or characteristic described in connection with that feature and / or instance may be included in at least one feature and / or instance of the claimed object. Therefore, the appearance of the phrases "in one instance," "an instance," "in some instances," or "in some implementations," or other similar phrases throughout this specification, does not necessarily represent the same feature, instance, and / or limitation. Furthermore, a particular feature, structure, or characteristic may be combined in one or more instances and / or features.

[0168] Some portions of the detailed description included herein are presented based on algorithms or symbolic representations of operations on binary bit signals stored in the memory of a particular device or dedicated computing device or platform. In the context of this particular specification, the term "particular device," etc., includes general-purpose computers once it is programmed to perform a particular operation according to instructions from program software. Algorithm descriptions or symbolic representations are examples of techniques used by those skilled in signal processing or related fields to communicate their work to others skilled in the art. Here, an algorithm is generally considered to be a self-consistent sequence of operations or similar signal processing that leads to a desired result. In this case, the operation or processing involves the physical manipulation of a physical quantity. Typically, although not strictly necessary, this quantity may take the form of an electrical or magnetic signal that can be stored, transmitted, combined, compared, or otherwise manipulated. Primarily for general reasons, it has proven convenient to sometimes refer to such signals as bits, data, values, elements, symbols, characters, items, numerical values, numerals, etc. However, it should be understood that all such or similar terms should be associated with the appropriate physical quantity and are merely convenient labels. Unless otherwise expressly stated, as will be apparent from the discussion herein, it should be understood that the use of terms such as "processing," "computing," "calculating," and "determining" throughout this specification refers to the actions or processes of a specific device (such as a dedicated computer, dedicated computing device, or similar dedicated electronic computing device). Therefore, in the context of this specification, a dedicated computer or similar dedicated electronic computing device is capable of manipulating or transforming signals, which typically represent physical, electronic, or magnetic quantities in memory, registers, or other information storage, transmission, or display devices of the dedicated computer or similar dedicated electronic computing device.

[0169] In the foregoing detailed description, numerous specific details have been set forth to provide a thorough understanding of the claimed object. However, those skilled in the art will understand that the claimed object can be implemented without such specific details. In other instances, methods and apparatus known to the general art have not been described in detail to avoid obscuring the claimed object.

[0170] The terms "and," "or," and "and / or" as used herein can have a variety of meanings, which are expected to depend at least in part on the context in which they are used. Generally, when used to relate a list such as A, B, or C, "or" is intended to mean A, B, and C (in this case, used in an inclusive sense) and A, B, or C (in this case, used in an exclusive sense). Furthermore, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular, or to describe multiple features, structures, or characteristics, or some other combination of features, structures, or characteristics. However, it should be noted that this example is merely illustrative and the object of the claim is not limited to this example.

[0171] Although features which are currently considered exemplary have been described and illustrated, those skilled in the art will understand that various other modifications and substitutions can be made without departing from the claimed subject matter. Furthermore, many modifications can be made to adapt specific situations to the teachings of the claimed subject matter without departing from the central concepts described herein.

[0172] Examples of implementation methods are described in the following numbered clauses: 1. A method for selecting an anchor UE for locating a target user equipment (UE) in a wireless network, comprising the following steps: From a plurality of candidate anchor UEs, obtain one or more positioning measurements of the candidate anchor UE and a measurement quality metric for each of the positioning measurements; and At least one candidate anchor UE is selected from a plurality of candidate anchor UEs based on one or more measurement quality metrics from the one or more candidate anchor UEs for use in locating the target UE. 2. The method according to Clause 1, wherein obtaining one or more positioning measurements and measurement quality metrics of the candidate anchor UE includes obtaining one or more positioning measurements and measurement quality metrics of the candidate anchor UE from one or more NR-based positioning measurement reports of the candidate anchor UE. 3. According to one or more of the methods in Clauses 1-2, wherein one or more positioning measurements include one or more reference signal time differences (RSTDs) measured by the candidate anchor UE using positioning reference signal (PRS) resources obtained from one or more devices in the radio network. 4. According to one or more of the methods in Clauses 1-3, wherein: UE-based positioning will be performed by the target UE; and One or more location measurement reports are obtained by the target UE from the candidate anchor UE via the side link (SL) between the target UE and the candidate anchor UE. 5. The method according to one or more of the provisions 1-4 also includes the following steps: the target UE provides one or more of the PRS resources to the candidate anchor UE via the SL. 6. The method according to one or more of the provisions 1-3, wherein: UE-assisted localization for the target UE will be performed by the location server of the wireless network; One or more PRS resources are provided by the base station to the candidate anchor UE on the downlink (DL); One or more positioning measurement reports are provided from candidate anchor UEs to the base station; One or more positioning measurements and measurement quality metrics from one or more positioning measurement reports are provided from the base station to the location server; and Selecting at least one candidate anchor UE involves a location server selecting a candidate anchor UE as the anchor UE based on one or more positioning measurements and measurement quality metrics. 7. The method according to Clause 1, wherein for one or more candidate anchor UEs, each positioning measurement and associated measurement quality metric are independent of Radio Access Technology (RAT). 8. The method of one or more of Clauses 1-7, wherein each positioning measurement and associated measurement quality metric are determined by the candidate anchor UE using a Global Navigation Satellite System (GNSS). 9. The method according to one or more of the provisions 1-7, wherein: UE-based positioning will be performed by the target UE; and One or more positioning measurements and measurement quality metrics of the candidate anchor UE are obtained from the candidate anchor UE via a side link (SL) between the target UE and the candidate anchor UE. 10. The method according to one or more of clauses 1-7, wherein: UE-assisted localization of the target UE will be performed by the location server of the wireless network; One or more positioning measurements and measurement quality metrics are provided from candidate anchor UEs to the base station; One or more positioning measurements and measurement quality metrics are provided from the base station to the location server; and Selecting at least one candidate anchor UE involves a location server selecting a candidate anchor UE as the anchor UE based on one or more positioning measurements and measurement quality metrics. 11. The method according to Clause 1 also includes the following steps: determining the variability of measurement quality metrics for a plurality of candidate anchor UEs, wherein at least one candidate anchor UE is selected based on the determined variability. 12. The method according to one or more of the clauses 1-11, wherein variability includes the mean and variance of the quality measure. 13. The method according to Clause 1, wherein the selection of the at least one candidate anchor UE is also based on the link quality of the side link (SL) between the target UE and the one or more candidate anchor UEs. 14. An apparatus configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, comprising: At least one transceiver; At least one memory; and At least one processor coupled to at least one transceiver and at least one memory, wherein the at least one processor is configured to enable the device to: Measurement quality measures of one or more positioning measurements of a candidate anchor UE and each of the positioning measurements are obtained from one or more candidate anchor UEs from a plurality of candidate anchor UEs via at least one transceiver; and At least one candidate anchor UE is selected from a plurality of candidate anchor UEs by at least one processor based on one or more measurement quality metrics from one or more candidate anchor UEs for positioning the target UE. 15. The device according to Clause 14, wherein in order to obtain one or more positioning measurements and measurement quality metrics of the candidate anchor UE, at least one processor is configured to enable the device to obtain one or more positioning measurements and measurement quality metrics of the candidate anchor UE from one or more NR-based positioning measurement reports from the candidate anchor UE. 16. A device pursuant to one or more of Clauses 14-15, wherein one or more positioning measurements include one or more reference signal time differences (RSTDs) measured by the candidate anchor UE using Position Reference Signal (PRS) resource measurements obtained from one or more devices in the radio network. 17. Equipment according to one or more of Clauses 14-16, wherein: UE-based positioning is configured to be performed by the target UE; and At least one processor is configured to enable the device to obtain one or more location measurement reports from the candidate anchor UE via at least one transceiver via a side link (SL) between the target UE and the candidate anchor UE. 18. An apparatus pursuant to one or more of Clauses 14-17, wherein at least one processor is configured to enable the apparatus to provide one or more PRS resources of PRS resources to a candidate anchor UE via at least one transceiver and via SL, wherein the apparatus is the target UE. 19. Equipment according to one or more of Clauses 14-16, wherein: The device is a location server in the wireless network configured to perform UE-assisted localization for a target UE; One or more PRS resources will be provided by the base station to the candidate anchor UE on the downlink (DL); One or more positioning measurement reports will be provided to the base station by the candidate anchor UE; One or more positioning measurements and measurement quality metrics from one or more positioning measurement reports will be provided from the base station to the location server; and In order to select at least one candidate anchor UE, at least one processor is configured to enable the device to select the candidate anchor UE as the anchor UE via the at least one processor based on one or more positioning measurements and measurement quality metrics. 20. Equipment pursuant to Clause 14, wherein for one or more candidate anchor UEs, each positioning measurement and associated measurement quality metric are independent of Radio Access Technology (RAT). 21. Equipment pursuant to one or more of Clauses 14-20, wherein each positioning measurement and associated measurement quality metric shall be determined by the candidate anchor UE using a Global Navigation Satellite System (GNSS). 22. Equipment under one or more of Clauses 14-20, wherein: The device is a target UE configured to perform UE-based positioning; and At least one processor is configured to enable the device to obtain one or more positioning measurements and measurement quality metrics of the candidate anchor UE from the candidate anchor UE via the at least one transceiver and via a side link (SL) between the target UE and the candidate anchor UE. 23. Equipment according to one or more of Clauses 14-20, wherein: The device is a location server in a wireless network configured to perform UE-assisted localization of a target UE; One or more positioning measurements and measurement quality metrics will be provided from the candidate anchor UE to the base station; One or more positioning measurements and measurement quality metrics will be provided from the base station to the location server; and In order to select at least one candidate anchor UE, at least one processor is configured to enable the device to select the candidate anchor UE as the anchor UE via the at least one processor based on one or more positioning measurements and measurement quality metrics. 24. The device according to Clause 14, wherein at least one processor is configured to cause the device to determine, via at least one processor, the variability of a measurement quality metric of a plurality of candidate anchor UEs, wherein at least one candidate anchor UE is selected based on the determined variability. 25. Equipment according to one or more of Clauses 14-24, wherein variability includes the mean and variance of the measured quality measure. 26. The device pursuant to Clause 14, wherein the selection of at least one candidate anchor UE is also based on the link quality of the side link (SL) between the target UE and one or more candidate anchor UEs. 27. A non-transitory computer-readable medium storing instructions, which, when executed by at least one processor of a device configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, cause the device to: Obtain, via at least one transceiver and from one or more candidate anchor UEs from a plurality of candidate anchor UEs, one or more positioning measurements of the candidate anchor UEs and a measurement quality metric for each of the one or more positioning measurements; and At least one candidate anchor UE is selected from a plurality of candidate anchor UEs by at least one processor based on one or more measurement quality metrics from one or more candidate anchor UEs for positioning the target UE. 28. A computer-readable medium pursuant to Clause 27, wherein execution of instructions causes the device to obtain one or more positioning measurements and measurement quality measures of the candidate anchor UE in one or more NR-based positioning measurement reports from the candidate anchor UE when obtaining one or more positioning measurements and measurement quality measures of the candidate anchor UE. 29. A computer-readable medium pursuant to one or more of Clauses 27-28, wherein one or more positioning measurements include one or more reference signal time differences (RSTDs) measured by the candidate anchor UE using positioning reference signal (PRS) resources obtained from one or more devices in the radio network. 30. Computer-readable media pursuant to one or more of clauses 27-29, wherein: UE-based positioning is configured to be performed by the target UE; and The execution of the instruction enables the device to obtain one or more positioning measurement reports from the candidate anchor UE via at least one transceiver and via the side link (SL) between the target UE and the candidate anchor UE. 31. A computer-readable medium pursuant to one or more of the provisions 27-30, wherein execution of instructions causes the device to provide one or more PRS resources of PRS resources to the candidate anchor UE via at least one transceiver and via SL, wherein the device is the target UE. 32. Computer-readable media pursuant to one or more of Clauses 27-29, wherein: The device is a location server in a wireless network configured to perform UE-assisted positioning for the target UE; One or more PRS resources will be provided by the base station to the candidate anchor UE on the downlink (DL); One or more positioning measurement reports will be provided to the base station by the candidate anchor UE; One or more positioning measurements and measurement quality metrics from one or more positioning measurement reports will be provided from the base station to the location server; and The execution of the instruction causes the device to select at least one candidate anchor UE as the anchor UE via at least one processor based on one or more positioning measurements and measurement quality metrics when selecting at least one candidate anchor UE. 33. Computer-readable media pursuant to Clause 27, wherein for one or more candidate anchor UEs, each positioning measurement and associated measurement quality metric are independent of Radio Access Technology (RAT). 34. Computer-readable media pursuant to one or more of Clauses 27-33, wherein each positioning measurement and associated measurement quality metric shall be determined by the candidate anchor UE using a Global Navigation Satellite System (GNSS). 35. Computer-readable media pursuant to one or more of clauses 27-33, wherein: The device is a target UE configured to perform UE-based positioning; and The execution of the instruction enables the device to obtain one or more positioning measurements and measurement quality metrics of the candidate anchor UE from the candidate anchor UE via at least one transceiver and via a side link (SL) between the target UE and the candidate anchor UE. 36. Computer-readable media pursuant to one or more of clauses 27-33, wherein: The device is a location server in a wireless network configured to perform UE-assisted localization of a target UE; One or more positioning measurements and measurement quality metrics will be provided from the candidate anchor UE to the base station; One or more positioning measurements and measurement quality metrics will be provided from the base station to the location server; and The execution of the instruction causes the device to select at least one candidate anchor UE as the anchor UE via at least one processor based on one or more positioning measurements and measurement quality metrics when selecting at least one candidate anchor UE. 37. A computer-readable medium pursuant to Clause 27, wherein execution of instructions causes a device, via at least one processor, to determine the variability of a measurement quality metric of a plurality of candidate anchor UEs, wherein at least one candidate anchor UE is selected based on the determined variability. 38. A computer-readable medium pursuant to one or more of Clauses 27-37, wherein variability includes the mean and variance of a measure of quality. 39. Computer-readable media pursuant to Clause 27, wherein the selection of at least one candidate anchor UE is also based on the link quality of the side link (SL) between the target UE and one or more candidate anchor UEs. 40. An apparatus for selecting an anchor UE for locating a target user equipment (UE) in a wireless network, comprising: A component for obtaining one or more positioning measurements of a candidate anchor UE and a measurement quality metric of each of the positioning measurements from one or more candidate anchor UEs among a plurality of candidate anchor UEs; and A component for selecting at least one candidate anchor UE from a plurality of candidate anchor UEs for positioning a target UE based on one or more measurement quality metrics from one or more candidate anchor UEs. 41. The device pursuant to Clause 40, wherein the components for obtaining one or more positioning measurements and measurement quality metrics of the candidate anchor UE include components for obtaining one or more positioning measurements and measurement quality metrics of the candidate anchor UE in one or more NR-based positioning measurement reports from the candidate anchor UE. 42. A device pursuant to one or more of the provisions 40-41, wherein one or more positioning measurements include one or more reference signal time differences (RSTDs) measured by the candidate anchor UE using positioning reference signal (PRS) resources obtained from one or more devices in the radio network. 43. Equipment pursuant to one or more of clauses 40-42, wherein: UE-based positioning will be performed by the target UE; and One or more location measurement reports are obtained by the target UE from the candidate anchor UE via the side link (SL) between the target UE and the candidate anchor UE. 44. The equipment pursuant to one or more of the provisions of clauses 40-43 also includes a component for providing one or more of the PRS resources to the candidate anchor UE via the SL by the target UE. 45. Equipment pursuant to one or more of clauses 40-42, wherein: UE-assisted localization for the target UE will be performed by the location server of the wireless network; One or more PRS resources will be provided by the base station to the candidate anchor UE on the downlink (DL); One or more positioning measurement reports will be provided from the candidate anchor UE to the base station; One or more positioning measurements and measurement quality metrics from one or more positioning measurement reports will be provided from the base station to the location server; and The component for selecting at least one candidate anchor UE includes a location server for selecting candidate anchor UEs as anchor UEs based on one or more positioning measurements and measurement quality metrics. 46. ​​Equipment pursuant to Clause 40, wherein for one or more candidate anchor UEs, each positioning measurement and associated measurement quality metric are independent of Radio Access Technology (RAT). 47. Equipment pursuant to one or more of Clauses 40-46, wherein each positioning measurement and associated measurement quality metric shall be determined by the candidate anchor UE using a Global Navigation Satellite System (GNSS). 48. Equipment pursuant to one or more of clauses 40-46, wherein: UE-based positioning will be performed by the target UE; and One or more positioning measurements and measurement quality metrics of the candidate anchor UE are obtained from the candidate anchor UE via a side link (SL) between the target UE and the candidate anchor UE. 49. Equipment pursuant to one or more of clauses 40-46, wherein: UE-assisted localization of the target UE will be performed by the location server of the wireless network; One or more positioning measurements and measurement quality metrics will be provided from the candidate anchor UE to the base station; One or more positioning measurements and measurement quality metrics will be provided from the base station to the location server; and The component for selecting at least one candidate anchor UE includes a location server for selecting candidate anchor UEs as anchor UEs based on one or more positioning measurements and measurement quality metrics. 50. The device pursuant to Clause 40 also includes a component for determining the variability of a measurement quality metric for a plurality of candidate anchor UEs, wherein at least one candidate anchor UE is selected based on the determined variability. 51. Equipment pursuant to one or more of Clauses 40-50, wherein variability includes the mean and variance of the measured quality measure. 52. The device pursuant to Clause 40, wherein the selection of at least one candidate anchor UE is also based on the link quality of the side link (SL) between the target UE and the one or more candidate anchor UEs. 53. A method for selecting an anchor UE for locating a target user equipment (UE) in a wireless network, comprising the following steps: For one or more candidate anchor UEs from a plurality of candidate anchor UEs, obtain the action state of the candidate anchor UE; and Based on one or more action states, at least one candidate anchor UE is selected from a plurality of candidate anchor UEs for use in locating the target UE. 54. The method according to Clause 53, wherein obtaining the action state of the candidate anchor UE includes obtaining the action state from the candidate anchor UE, wherein the action state is determined by the candidate anchor UE. 55. The method of one or more of the provisions 53-54, wherein the action state determined by the candidate anchor UE depends on the radio access technology (RAT). 56. The method of one or more of the provisions 53-54, wherein the action state determined by the candidate anchor UE is independent of the radio access technology (RAT). 57. One or more of the methods in Clauses 53-56, wherein the action state is determined by the candidate anchor UE using an inertial measurement unit (IMU). 58. The method of one or more of Clauses 53-54, wherein the action status is provided periodically by the candidate anchor UE. 59. The method according to one or more of the provisions 53-54, wherein the action status is provided by the candidate anchor UE when the action status is greater than the action threshold. 60. The method according to one or more of clauses 53-54, wherein: UE-based positioning will be performed by the target UE; and The action status is obtained by the target UE from the candidate anchor UE via the side link (SL) between the target UE and the candidate anchor UE. 61. The method according to Clause 53, wherein obtaining the action status of the candidate anchor UE includes determining the action status based on the location history of the candidate anchor UE. 62. One or more of the methods specified in Clauses 53-61, wherein: UE-assisted localization of the target UE will be performed by the location server of the wireless network; and The location history of the candidate anchor UE is determined by the location server based on one or more reports from the candidate anchor UE. 63. The method according to Clause 53, wherein the action state of the candidate anchor UE includes the speed of the candidate anchor UE. 64. An apparatus configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, comprising: At least one transceiver; At least one memory; and At least one processor coupled to at least one transceiver and at least one memory, wherein the at least one processor is configured to cause the device to: The action state of the candidate anchor UE is obtained via one or more of at least one transceiver or at least one processor and for one or more of a plurality of candidate anchor UEs; and At least one candidate anchor UE is selected from a plurality of candidate anchor UEs by at least one processor based on one or more operational states for use in locating the target UE. 65. The device according to Clause 64, wherein in order to obtain the operational state of the candidate anchor UE, at least one processor is configured to cause the device to obtain the operational state from the candidate anchor UE via at least one transceiver, wherein the operational state is determined by the candidate anchor UE. 66. Equipment pursuant to one or more of Clauses 64-65, wherein the operational state determined by the candidate anchor UE depends on the Radio Access Technology (RAT). 67. Equipment under one or more of Clauses 64-65, wherein the operational state determined by the candidate anchor UE is independent of Radio Access Technology (RAT). 68. A device pursuant to one or more of Clauses 64-67, wherein the operational status is determined by the candidate anchor UE using an inertial measurement unit (IMU). 69. A device pursuant to one or more of Clauses 64-65, wherein the operational status is periodically provided by the candidate anchor UE. 70. A device pursuant to one or more of Clauses 64-65, wherein the action status is provided by the candidate anchor UE when the action status is greater than the action threshold. 71. Equipment according to one or more of clauses 64-65, wherein: The device is a target UE configured to perform UE-based positioning; and At least one processor is configured to enable the device to obtain the action status from the candidate anchor UE via at least one transceiver, via a side link (SL) between the target UE and the candidate anchor UE. 72. The device according to Clause 64, wherein in order to obtain the operational state of a candidate anchor UE, at least one processor is configured to cause the device to determine the operational state via the at least one processor based on the positioning history of the candidate anchor UE. 73. Equipment pursuant to one or more of clauses 64-72, wherein: The device is a location server in a wireless network configured to perform UE-assisted localization of a target UE; and At least one processor is configured to enable the device to determine the location history of the candidate anchor UE based on one or more reports from the candidate anchor UE via the at least one processor. 74. The device pursuant to Clause 64, wherein the operational status of the candidate anchor UE includes the speed of the candidate anchor UE. 75. A non-transitory computer-readable medium storing instructions, which, when executed by at least one processor of a device for selecting an anchor UE for locating a target user equipment (UE) in a wireless network, cause the device to: The action state of the candidate anchor UE is obtained via one or more of at least one transceiver or at least one processor and for one or more of a plurality of candidate anchor UEs; and At least one candidate anchor UE is selected from a plurality of candidate anchor UEs by at least one processor based on one or more operational states for use in locating the target UE. 76. A computer-readable medium pursuant to Clause 75, wherein execution of instructions causes the device to obtain the operational status of the candidate anchor UE via at least one transceiver when the device obtains the operational status of the candidate anchor UE, wherein the operational status is determined by the candidate anchor UE. 77. A computer-readable medium pursuant to one or more of Clauses 75-76, wherein the operational status determined by the candidate anchor UE depends on the Radio Access Technology (RAT). 78. Computer-readable media pursuant to one or more of Clauses 75-76, wherein the operational status determined by the candidate anchor UE is independent of Radio Access Technology (RAT). 79. A computer-readable medium pursuant to one or more of Clauses 75-78, wherein the operational status is determined by the candidate anchor UE using an inertial measurement unit (IMU). 80. Computer-readable media pursuant to one or more of Clauses 75-76, wherein the action status is periodically provided by the candidate anchor UE. 81. Computer-readable media according to one or more of Clauses 75-76, wherein the action status is provided by the candidate anchor UE when the action status is greater than the action threshold. 82. Computer-readable media pursuant to one or more of Clauses 75-76, wherein: The device is a target UE configured to perform UE-based positioning; and The execution of the command enables the device to obtain the operational status from the candidate anchor UE via at least one transceiver and via the side link (SL) between the target UE and the candidate anchor UE. 83. A computer-readable medium pursuant to Clause 75, wherein the execution of instructions causes the device, upon obtaining the operational status of a candidate anchor UE, to determine the operational status via at least one processor based on the positioning history of the candidate anchor UE. 84. Computer-readable media pursuant to one or more of clauses 75-83, wherein: The device is a location server in a wireless network configured to perform UE-assisted localization of a target UE; and The execution of the instruction causes the device to determine the location history of the candidate anchor UE via at least one processor based on one or more reports from the candidate anchor UE. 85. Computer-readable media pursuant to Clause 75, wherein the operational status of the candidate anchor UE includes the speed of the candidate anchor UE. 86. An apparatus for selecting an anchor UE for locating a target user equipment (UE) in a wireless network, comprising: A component for obtaining the action state of one or more candidate anchor UEs from a plurality of candidate anchor UEs; and A component for selecting at least one candidate anchor UE from a plurality of candidate anchor UEs for locating a target UE based on one or more action states. 87. The device pursuant to Clause 86, wherein the component for obtaining the action state of the candidate anchor UE includes a component for obtaining the action state from the candidate anchor UE, wherein the action state is determined by the candidate anchor UE. 88. Equipment pursuant to one or more of Clauses 86-87, wherein the operational state determined by the candidate anchor UE depends on the Radio Access Technology (RAT). 89. Equipment under one or more of Clauses 86-87, wherein the operational state determined by the candidate anchor UE is independent of Radio Access Technology (RAT). 90. A device pursuant to one or more of Clauses 86-89, wherein the operational status is determined by the candidate anchor UE using an inertial measurement unit (IMU). 91. A device pursuant to one or more of Clauses 86-87, wherein the operational status is periodically provided by the candidate anchor UE. 92. A device according to one or more of Clauses 86-87, wherein the action status is provided by the candidate anchor UE when the action status is greater than the action threshold. 93. Equipment under one or more of Clauses 86-87, wherein: UE-based positioning will be performed by the target UE; and The action status is obtained by the target UE from the candidate anchor UE via the side link (SL) between the target UE and the candidate anchor UE. 94. An apparatus pursuant to one or more of Clauses 86-86, wherein the component for obtaining the operational status of a candidate anchor UE includes a component for determining the operational status based on the positioning history of the candidate anchor UE. 95. Equipment under one or more of clauses 86-94, wherein: UE-assisted localization of the target UE will be performed by the location server of the wireless network; and The location history of the candidate anchor UE is determined by the location server based on one or more reports from the candidate anchor UE. 96. The device pursuant to Clause 86, wherein the operational status of the candidate anchor UE includes the speed of the candidate anchor UE. 97. A method for selecting an anchor UE for locating a target user equipment (UE) in a wireless network, comprising the following steps: Information associated with a plurality of geometric precision factors (GDOPs) is obtained, wherein each GDOP is determined for different combinations of candidate anchor UEs for the target UE from a plurality of candidate anchor UEs; and One or more anchor UEs are selected from a plurality of candidate anchor UEs for use in locating the target UE, wherein the selection is based on the information obtained. 98. The method according to Clause 97, wherein UE-assisted positioning is performed by a location server of a wireless network. 99. The method according to one or more of Clauses 97-98, wherein obtaining information associated with a plurality of GDOPs includes obtaining a plurality of GDOPs from a base station, wherein: Multiple GDOPs are obtained by the base station from one of the following: Target UE; or Relay UE between base station and target UE; and The location server selects one or more anchor UEs for positioning the target UE based on a plurality of GDOPs obtained from the base station. 100. The method according to one or more of Clauses 97-98, wherein obtaining information associated with a plurality of GDOPs includes obtaining from the base station an indication for one or more preferred anchor UEs for the target UE, wherein: One or more preferred anchor UEs are determined by the target UE based on a plurality of GDOPs; Indications for one or more preferred anchor UEs are provided by the target UE to one of the following: base station; or Relay UE between base station and target UE; and The location server selects one or more anchor UEs for positioning the target UE based on the indication of one or more preferred anchor UEs. 101. The method according to one or more of Clauses 97-98, wherein the location server selects one or more anchor UEs for positioning the target UE, and also selects anchor UEs for positioning one or more UEs other than the target UE. 102. The method according to Clause 97, wherein obtaining information associated with a plurality of GDOPs includes the target UE determining the plurality of GDOPs, wherein UE-based positioning will be performed by the target UE. 103. An apparatus configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, comprising: At least one transceiver; At least one memory; and At least one processor coupled to at least one transceiver and at least one memory, wherein the at least one processor is configured to enable the device to: Information associated with a plurality of geometric precision factors (GDOPs) is obtained via one or more of at least one transceiver or at least one processor, wherein each GDOP is determined for different combinations of candidate anchor UEs for the target UE from a plurality of candidate anchor UEs; and One or more anchor UEs are selected from a plurality of candidate anchor UEs for locating the target UE via one or more of at least one transceiver or at least one processor, wherein the selection is based on the information obtained. 104. The device pursuant to Clause 103, wherein the device is a location server of a wireless network, and the location server is configured to perform UE-assisted positioning. 105. An apparatus pursuant to one or more of clauses 103-104, wherein, in order to obtain information associated with a plurality of GDOPs, at least one processor is configured to cause the apparatus to: A plurality of GDOPs are obtained from the base station via at least one transceiver, wherein the plurality of GDOPs are obtained by the base station from one of the following: The target UE; or Relay UE between base station and target UE; One or more anchor UEs are selected by at least one processor for locating the target UE based on a plurality of GDOPs obtained from the base station. 106. An apparatus pursuant to one or more of clauses 103-104, wherein, in order to obtain information associated with a plurality of GDOPs, at least one processor is configured to cause the apparatus to: Indications for one or more preferred anchor UEs for the target UE are obtained from the base station via at least one transceiver, wherein: One or more preferred anchor UEs are determined by the target UE based on a plurality of GDOPs; Indications for one or more preferred anchor UEs are provided by the target UE to one of the following: base station; or Relay UE between base station and target UE; and One or more anchor UEs are selected via at least one processor for positioning a target UE based on the indication of one or more preferred anchor UEs. 107. A device pursuant to one or more of Clauses 103-104, wherein the selection of one or more anchor UEs for locating a target UE is also based on the selection of anchor UEs for locating one or more UEs other than the target UE. 108. The device pursuant to Clause 103, wherein the device is a target UE configured to perform UE-based positioning, wherein in order to obtain information associated with a plurality of GDOPs, at least one processor is configured to cause the device to determine the plurality of GDOPs via the at least one processor. 109. A non-transitory computer-readable medium comprising instructions that, when executed by at least one processor of a device configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, cause the device to: Information associated with a plurality of geometric precision factors (GDOPs) is obtained via one or more of at least one transceiver or at least one processor, wherein each GDOP is determined for different combinations of candidate anchor UEs for the target UE from a plurality of candidate anchor UEs; and One or more anchor UEs are selected from a plurality of candidate anchor UEs for locating the target UE via one or more of at least one transceiver or at least one processor, wherein the selection is based on the information obtained. 110. Computer-readable media pursuant to Clause 109, wherein the device is a location server of a wireless network, and the location server is configured to perform UE-assisted positioning. 111. A computer-readable medium pursuant to one or more of clauses 109-110, wherein execution of instructions causes the device to, upon obtaining information associated with a plurality of GDOPs: A plurality of GDOPs are obtained from the base station via at least one transceiver, wherein the plurality of GDOPs are obtained by the base station from one of the following: Target UE; or Relay UE between base station and target UE; One or more anchor UEs are selected by at least one processor for locating the target UE based on a plurality of GDOPs obtained from the base station. 112. A computer-readable medium pursuant to one or more of clauses 109-110, wherein execution of instructions causes the device to, upon obtaining information associated with a plurality of GDOPs: Indications for one or more preferred anchor UEs for the target UE are obtained from the base station via at least one transceiver, wherein: One or more preferred anchor UEs are determined by the target UE based on a plurality of GDOPs; Indications for one or more preferred anchor UEs are provided by the target UE to one of the following: base station; or Relay UE between base station and target UE; and One or more anchor UEs are selected via at least one processor for positioning a target UE based on the indication of one or more preferred anchor UEs. 113. A computer-readable medium pursuant to one or more of the provisions of clauses 109-110, wherein the selection of one or more anchor UEs for locating a target UE is also based on the selection of anchor UEs for locating one or more UEs other than the target UE. 114. A computer-readable medium pursuant to Clause 109, wherein the device is configured to perform a UE-based positioning target UE, wherein the execution of instructions causes the device to determine the plurality of GDOPs via at least one processor when it obtains information associated with the plurality of GDOPs. 115. An apparatus for selecting an anchor UE for locating a target user equipment (UE) in a wireless network, comprising: A component for obtaining information associated with a plurality of geometric precision factors (GDOPs), wherein each GDOP is determined for different combinations of candidate anchor UEs for the target UE from a plurality of candidate anchor UEs; and A component for selecting one or more anchor UEs from a plurality of candidate anchor UEs for locating a target UE, wherein the selection is based on the information obtained. 116. The device pursuant to Clause 115, wherein UE-assisted positioning is performed by a location server of a wireless network. 117. The method according to one or more of clauses 115-116, wherein the component for obtaining information associated with a plurality of GDOPs includes a component for obtaining a plurality of GDOPs from a base station, wherein: Multiple GDOPs are obtained by the base station from one of the following: Target UE; or Relay UE between base station and target UE; and The location server selects one or more anchor UEs for positioning the target UE based on a plurality of GDOPs obtained from the base station. 118. An apparatus pursuant to one or more of Clauses 115-116, wherein the component for obtaining information associated with a plurality of GDOPs includes a component for obtaining from a base station an indication for one or more preferred anchor UEs for the target UE, wherein: One or more preferred anchor UEs are determined by the target UE based on a plurality of GDOPs; Indications for one or more preferred anchor UEs are provided by the target UE to one of the following: base station; or Relay UE between base station and target UE; and The location server selects one or more anchor UEs for positioning the target UE based on the indication of one or more preferred anchor UEs. 119. A device pursuant to one or more of Clauses 115-116, wherein the location server selects one or more anchor UEs for positioning a target UE, and also selects anchor UEs for positioning one or more UEs other than the target UE. 120. The method according to Clause 115, wherein the component for obtaining information associated with a plurality of GDOPs includes a component for determining the plurality of GDOPs by the target UE, wherein the UE-based positioning will be performed by the target UE. 121. A method for selecting an anchor UE for locating a target user equipment (UE) in a wireless network, comprising the following steps: Obtain information associated with one or more of the following: Positioning measurements and measurement quality metrics for one or more candidate anchor UEs; The action status of one or more candidate anchor UEs; or Geometric precision factor (GDOP) associated with one or more candidate anchor UEs; and Based on the obtained information, at least one candidate anchor UE is selected from a plurality of candidate anchor UEs for use in locating the target UE. 122. The method according to Clause 121, wherein obtaining information includes obtaining a measurement quality metric of one or more positioning measurements of the candidate anchor UE and each of the one or more positioning measurements from one or more candidate anchor UEs among a plurality of candidate anchor UEs. 123. The method according to one or more of the provisions 121-122, wherein obtaining information includes obtaining the action status of one or more candidate anchor UEs among a plurality of candidate anchor UEs. 124. The method according to one or more of the provisions 121-123, wherein obtaining information includes obtaining information associated with a plurality of GDOPs, wherein each GDOP determines different combinations of candidate anchor UEs for a target UE from a plurality of candidate anchor UEs. 125. An apparatus configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, comprising: At least one transceiver; At least one memory; and At least one processor coupled to at least one transceiver and at least one memory, wherein the at least one processor is configured to enable the device to: Obtain information associated with one or more of the following: Positioning measurements and measurement quality metrics for one or more candidate anchor UEs; The action status of one or more candidate anchor UEs; or Geometric precision factor (GDOP) associated with one or more candidate anchor UEs; and Based on the obtained information, at least one candidate anchor UE is selected from a plurality of candidate anchor UEs for use in locating the target UE. 126. The device pursuant to Clause 125, wherein, in order to obtain information, at least one processor is configured to cause the device to obtain, from one or more candidate anchor UEs among a plurality of candidate anchor UEs, a measurement quality metric of one or more positioning measurements of the candidate anchor UE and each of the positioning measurements. 127. A device pursuant to one or more of the provisions of 125-126, wherein, in order to obtain information, at least one processor is configured to enable the device to obtain the action state of one or more candidate anchor UEs among a plurality of candidate anchor UEs. 128. An apparatus pursuant to one or more of Clauses 125-126, wherein, in order to obtain information, at least one processor is configured to enable the apparatus to obtain information associated with a plurality of GDOPs, wherein each GDOP is determined for a different combination of candidate anchor UEs from a plurality of candidate anchor UEs. 129. A non-transitory computer-readable medium comprising instructions that, when executed by at least one processor of a device configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, cause the device to: Obtain information associated with one or more of the following: Positioning measurements and measurement quality metrics for one or more candidate anchor UEs; The action status of one or more candidate anchor UEs; or Geometric precision factor (GDOP) associated with one or more candidate anchor UEs; and Based on the obtained information, at least one candidate anchor UE is selected from a plurality of candidate anchor UEs for use in locating the target UE. 130. A computer-readable medium pursuant to Clause 129, wherein execution of instructions causes the device, upon obtaining information, to obtain, from one or more candidate anchor UEs among a plurality of candidate anchor UEs, a measurement quality measure of one or more positioning measurements of the candidate anchor UEs and each of the one or more positioning measurements. 131. A computer-readable medium pursuant to one or more of the provisions 129-130, wherein execution of instructions causes the device to obtain the action status of one or more candidate anchor UEs among a plurality of candidate anchor UEs when information is obtained. 132. A computer-readable medium pursuant to one or more of the provisions 129-131, wherein execution of instructions causes the device to obtain information associated with a plurality of GDOPs when it obtains information, wherein each GDOP is determined for a different combination of candidate anchor UEs from a plurality of candidate anchor UEs. 133. An apparatus configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, comprising: A component for obtaining information associated with one or more of the following: Positioning measurements and measurement quality metrics for one or more candidate anchor UEs; The action status of one or more candidate anchor UEs; or Geometric precision factor (GDOP) associated with one or more candidate anchor UEs; and A component for selecting at least one candidate anchor UE from a plurality of candidate anchor UEs for locating a target UE based on the obtained information. 134. The device pursuant to Clause 133, wherein the component for obtaining information includes a component for obtaining a measurement quality metric of one or more positioning measurements of the candidate anchor UE and each of the positioning measurements from one or more candidate anchor UEs among a plurality of candidate anchor UEs. 135. An apparatus pursuant to one or more of the provisions 133-134, wherein the component for obtaining information includes a component for obtaining the action status of one or more candidate anchor UEs among a plurality of candidate anchor UEs. 136. An apparatus pursuant to one or more of Clauses 133-135, wherein the component for obtaining information includes a component for obtaining information associated with a plurality of GDOPs, wherein each GDOP is determined for a different combination of candidate anchor UEs from a plurality of candidate anchor UEs.

[0173] Therefore, the object of protection is not intended to be limited to the specific instance disclosed, but can also include all forms that fall within the scope of the appended claim and its equivalents.

[0174] 100: Wireless Communication System 102: Base Station 102': Small Cell Base Station 102-1: Base Station 102-2: Base Station 102-3: Base Station 104:UE 110: Geographical coverage area 110': Coverage area 120: Communication Link 122: Backload Link 134: Backload Link 150: WLAN AP 152:WLAN STA 154: Communication Link 164:UE 170: Core Network 172: Location Server 180: Millimeter wave (mmW) base station 182:UE 184:mmW communication link 190:UE 192: D2D P2P Link 194: D2D P2P Link 200: Design 212: Source 220: Transmission Processor 230: Transfer (TX) Multiple-Input Multiple-Output (MIMO) Processor 232a: Modulator / Demodulator 232t: Modulator / Demodulator 234a: Antenna 234t: Antenna 236: MIMO Detector 238: Receiver Processor 239: Data Slot 240: Controller / Processor 242: Memory 244: Communication Unit 246: Scheduler 252a: Antenna 252r: Antenna 254a: Demodulator / Modulator 254r: Demodulator / Modulator 256: MIMO Detector 258: Receiver Processor 260: Data Slot 262: Source 264: Transmission Processor 266:TX MIMO processor 280: Controller / Processor 282: Memory 289: Network Controller 290: Controller / Processor 292: Memory 294: Communication Unit 300:UE 310: Processor 311: Memory 312: Software (SW) 313: Sensor 314: Transceiver Interface 315: Transceiver 316: User Interface 317: SPS Receiver 318: Camera 319: Positioning equipment 320: Busbar 330: Application Processor 331: Digital Signal Processor (DSP) 332: Modem Processor 333: Video Processor 334: Sensor Processor 340: Wireless transceiver 342: Transmitter 344: Receiver 346: Antenna 348: Wireless signal 350: Wired transceiver 352: Transmitter 354: Receiver 360: SPS signal 362: SPS Antenna 372: Anchor UE selects communication period module 400: Base Station 410: Processor 411: Memory 412: Software (SW) 415: Transceiver 420: Busbar 440: Wireless transceiver 442: Transmitter 444: Receiver 446: Antenna 448: Wireless signal 450: Wired transceiver 452: Transmitter 454: Receiver 472: Anchor UE selects communication period module 500: Server 510: Processor 511: Memory 512: Software (SW) 515: Transceiver 520: Busbar 540: Wireless Transceiver 542: Transmitter 544: Receiver 546: Antenna 548: Wireless signal 550: Wired transceiver 552: Transmitter 554: Receiver 572: Anchor UE selects communication period module 600: Wireless Communication System 700: Method 702: Steps 704: Steps 800: Method 802: Steps 804: Steps 900: Image 901: Figure 902:TRP 904:TRP 906: Scope 908: Range 910A: Positioning uncertainty 910B: Positioning uncertainty 1000: Method 1002: Steps 1004: Steps 1100: Method 1102: Steps 1104: Steps 1106: Steps 1108: Steps 1110: Steps

[0175] Domestic storage information (please note in order of storage institution, date, and number) none Overseas storage information (please note in the order of storage country, institution, date, and number) none

Claims

1. A method for selecting an anchor UE for locating a target user equipment (UE) in a wireless network, comprising the steps of: obtaining one or more positioning measurements of the candidate anchor UE and a measurement quality metric of each of the one or more positioning measurements from one or more candidate anchor UEs among a plurality of candidate anchor UEs; and selecting at least one candidate anchor UE from the plurality of candidate anchor UEs for locating the target UE based on the one or more measurement quality metrics from the one or more candidate anchor UEs.

2. According to the method of request item 1, the step of obtaining the one or more positioning measurements and measurement quality metrics of a candidate anchor UE includes the following steps: obtaining the one or more positioning measurements and measurement quality metrics of the candidate anchor UE from one or more NR-based positioning measurement reports from the candidate anchor UE.

3. The method according to claim 2, wherein the one or more positioning measurements include one or more reference signal time differences (RSTDs) measured by the candidate anchor UE using positioning reference signal (PRS) resources obtained from one or more devices in the radio network.

4. According to the method of request item 3, wherein: UE-based positioning will be performed by the target UE; and the one or more positioning measurement reports will be obtained by the target UE from the candidate anchor UE via a side link (SL) between the target UE and the candidate anchor UE.

5. The method according to request item 4 also includes the following steps: the target UE provides one or more of the PRS resources to the candidate anchor UE via the SL.

6. According to the method of request item 3, wherein: UE-assisted positioning for the target UE will be performed by a location server of the radio network; one or more of the PRS resources are provided to the candidate anchor UE by a base station on a downlink (DL); one or more location measurement reports are provided to the base station from a candidate anchor UE; one or more location measurements and measurement quality metrics from the one or more location measurement reports are provided to the location server from the base station; and the step of selecting the at least one candidate anchor UE includes the following steps: the location server selects a candidate anchor UE as an anchor UE based on the one or more location measurements and measurement quality metrics.

7. The method according to Request Item 1, wherein for the one or more candidate anchor UEs, each positioning measurement and associated measurement quality metric are independent of Radio Access Technology (RAT).

8. According to the method of request item 7, each positioning measurement and associated measurement quality metric are determined by the candidate anchor UE using a Global Navigation Satellite System (GNSS).

9. According to the method of request item 7, wherein: The UE-based positioning will be performed by the target UE; and the one or more positioning measurements and measurement quality metrics of a candidate anchor UE will be obtained from the candidate anchor UE via a side link (SL) between the target UE and the candidate anchor UE.

10. According to the method of request item 7, wherein: UE-assisted positioning of the target UE will be performed by a location server of the wireless network; one or more positioning measurements and measurement quality metrics are provided from a candidate anchor UE to a base station; one or more positioning measurements and measurement quality metrics are provided from the base station to the location server; and the step of selecting the at least one candidate anchor UE includes the following steps: the location server selects a candidate anchor UE as an anchor UE based on the one or more positioning measurements and measurement quality metrics.

11. The method according to claim 1 also includes the steps of: determining a variability of the measurement quality metric for the plurality of candidate anchor UEs, wherein the at least one candidate anchor UE is selected based on the determined variability.

12. The method according to claim 11, wherein the variability includes a mean and a variance of the quality measures of the measurements.

13. According to the method of request item 1, wherein the selection of the at least one candidate anchor UE is also based on the link quality of a side link (SL) between the target UE and the one or more candidate anchor UEs.

14. An apparatus configured to select for locating an anchor UE of a target user equipment (UE) in a radio network, comprising: At least one transceiver; At least one memory cell; and at least one processor coupled to the at least one transceiver and the at least one memory, wherein the at least one processor is configured to cause the device to: obtain, via the at least one transceiver and from one or more candidate anchor UEs among a plurality of candidate anchor UEs, one or more positioning measurements of the candidate anchor UE and a measurement quality metric of each of the one or more positioning measurements; and select, via the at least one processor, at least one candidate anchor UE from the plurality of candidate anchor UEs for positioning the target UE based on the one or more measurement quality metrics from the one or more candidate anchor UEs.

15. The device according to claim 14, wherein, in order to obtain the one or more positioning measurements and measurement quality metrics of a candidate anchor UE, the at least one processor is configured to cause the device to obtain the one or more positioning measurements and measurement quality metrics of the candidate anchor UE from one or more NR-based positioning measurement reports from the candidate anchor UE.

16. The device according to claim 15, wherein the one or more positioning measurements include one or more reference signal time differences (RSTDs) measured by the candidate anchor UE using positioning reference signal (PRS) resource measurements obtained from one or more devices in the radio network.

17. The device according to request item 16, wherein: UE-based positioning is configured to be performed by the target UE; and the at least one processor is configured to enable the device to obtain the one or more positioning measurement reports from the candidate anchor UE via the at least one transceiver, via a side link (SL) between the target UE and the candidate anchor UE.

18. The device according to request item 17, wherein the at least one processor is configured to provide one or more of the PRS resources to the candidate anchor UE via the at least one transceiver and via the SL, wherein the device is the target UE.

19. The device according to claim 16, wherein: The device is a location server in the wireless network configured to perform UE-assisted positioning for the target UE; one or more of the PRS resources will be provided to the candidate anchor UE by a base station on a downlink (DL); one or more location measurement reports will be provided to the base station by a candidate anchor UE; one or more location measurements and measurement quality metrics from the one or more location measurement reports will be provided to the location server from the base station; and in order to select the at least one candidate anchor UE, the at least one processor is configured to cause the device to select a candidate anchor UE as an anchor UE via the at least one processor based on the one or more location measurements and measurement quality metrics.

20. The device according to request item 14, wherein for the one or more candidate anchor UEs, each positioning measurement and associated measurement quality metric are independent of radio access technology (RAT).

21. The device according to request item 20, wherein each positioning measurement and associated measurement quality metric will be determined by the candidate anchor UE using a Global Navigation Satellite System (GNSS).

22. The device according to request item 20, wherein: The device is configured to perform UE-based positioning of the target UE; The at least one processor is configured to enable the device to obtain the one or more positioning measurements and measurement quality metrics of the candidate anchor UE from the candidate anchor UE via the at least one transceiver and via a side link (SL) between the target UE and the candidate anchor UE.

23. The device according to request item 20, wherein: The device is a location server in the wireless network configured to perform UE-assisted localization of the target UE; one or more location measurements and measurement quality metrics are provided from a candidate anchor UE to a base station; one or more location measurements and measurement quality metrics are provided from the base station to the location server; and in order to select the at least one candidate anchor UE, the at least one processor is configured to cause the device to select a candidate anchor UE as an anchor UE via the at least one processor based on the one or more location measurements and measurement quality metrics.

24. The device according to claim 14, wherein the at least one processor is configured to cause the device to determine, via the at least one processor, a variability of the equivalent measurement quality metric of the plurality of candidate anchor UEs, wherein the at least one candidate anchor UE is selected based on the determined variability.

25. The apparatus according to claim 24, wherein the variability includes a mean and a variance of the such measurement quality measures.

26. The device according to request item 14, wherein the selection of the at least one candidate anchor UE is also based on the link quality of a side link (SL) between the target UE and the one or more candidate anchor UEs.

27. A non-transitory computer-readable medium storing instructions, which, when executed by at least one processor of a device configured to select an anchor UE for locating a target user equipment (UE) in a wireless network, cause the device to: obtain, via at least one transceiver and from one or more candidate anchor UEs among a plurality of candidate anchor UEs, one or more positioning measurements of the candidate anchor UE and a measurement quality metric of each of the one or more positioning measurements; and select, via the at least one processor, at least one candidate anchor UE from the plurality of candidate anchor UEs for locating the target UE based on the one or more measurement quality metrics from the one or more candidate anchor UEs.

28. The computer-readable medium according to request item 27, wherein execution of the instructions causes the device to obtain the one or more positioning measurements and measurement quality measures of the candidate anchor UE in one or more NR-based positioning measurement reports from the candidate anchor UE when obtaining the one or more positioning measurements and measurement quality measures of the candidate anchor UE.

29. The computer-readable medium according to request item 28, wherein the one or more positioning measurements include one or more reference signal time differences (RSTDs) measured by the candidate anchor UE using positioning reference signal (PRS) resources obtained from one or more devices in the radio network.

30. Computer-readable media pursuant to request item 29, wherein: UE-based positioning is configured to be performed by the target UE; and the execution of such instructions causes the device to obtain one or more positioning measurement reports from the candidate anchor UE via the at least one transceiver, via a side link (SL) between the target UE and the candidate anchor UE.

31. Computer-readable media according to request item 30, wherein execution of the instructions causes the device to provide one or more of the PRS resources to the candidate anchor UE via the at least one transceiver and via the SL, wherein the device is the target UE.

32. Computer-readable media pursuant to request item 29, wherein: The device is a location server in the wireless network configured to perform UE-assisted positioning for the target UE; one or more of the PRS resources will be provided to the candidate anchor UE by a base station on a downlink (DL); one or more location measurement reports will be provided to the base station by a candidate anchor UE; one or more location measurements and measurement quality metrics from the one or more location measurement reports will be provided to the location server from the base station; and the execution of the instructions causes the device to select a candidate anchor UE as an anchor UE via the at least one processor based on the one or more location measurements and measurement quality metrics when selecting the at least one candidate anchor UE.

33. Computer-readable media according to request item 27, wherein for the one or more candidate anchor UEs, each positioning measurement and associated measurement quality metric are independent of radio access technology (RAT).

34. The computer-readable medium according to request item 33, wherein each positioning measurement and associated measurement quality metric will be determined by the candidate anchor UE using a Global Navigation Satellite System (GNSS).

35. Computer-readable media pursuant to request item 33, wherein: The device is configured to perform UE-based positioning of the target UE; and the execution of such instructions causes the device to obtain one or more positioning measurements and measurement quality metrics of the candidate anchor UE from a candidate anchor UE via the at least one transceiver, via a side link (SL) between the target UE and the candidate anchor UE.

36. Computer-readable media pursuant to request item 33, wherein: The device is a location server in the wireless network configured to perform UE-assisted localization of the target UE; one or more location measurements and measurement quality metrics are provided from a candidate anchor UE to a base station; one or more location measurements and measurement quality metrics are provided from the base station to the location server; and the execution of the instructions causes the device to select a candidate anchor UE as an anchor UE via the at least one processor based on the one or more location measurements and measurement quality metrics when selecting the at least one candidate anchor UE.

37. The computer-readable medium according to claim 27, wherein execution of the instructions causes the device to determine a variability of the measurement quality metrics of the plurality of candidate anchor UEs via the at least one processor, wherein the at least one candidate anchor UE is selected based on the determined variability.

38. The computer-readable medium according to request 37, wherein the variability includes a mean and a variance of the measured quality measures.

39. Computer-readable media according to request item 27, wherein the selection of the at least one candidate anchor UE is also based on the link quality of a side link (SL) between the target UE and the one or more candidate anchor UEs.

40. An apparatus for selecting an anchor UE for locating a target user equipment (UE) in a wireless network, comprising: A component for obtaining one or more positioning measurements of a candidate anchor UE and a measurement quality metric of each of the one or more positioning measurements from one or more candidate anchor UEs among a plurality of candidate anchor UEs; and a component for selecting at least one candidate anchor UE from the plurality of candidate anchor UEs for positioning the target UE based on the one or more measurement quality metrics from the one or more candidate anchor UEs.

41. The device according to claim 40, wherein the component for obtaining the one or more positioning measurements and measurement quality metrics of a candidate anchor UE includes a component for obtaining the one or more positioning measurements and measurement quality metrics of the candidate anchor UE in one or more NR-based positioning measurement reports from the candidate anchor UE.

42. The device according to claim 41, wherein the one or more positioning measurements include one or more reference signal time differences (RSTDs) measured by the candidate anchor UE using positioning reference signal (PRS) resources obtained from one or more devices in the radio network.

43. The device according to request item 42, wherein: UE-based positioning will be performed by the target UE; and the one or more positioning measurement reports will be obtained by the target UE from the candidate anchor UE via a side link (SL) between the target UE and the candidate anchor UE.

44. The device according to claim 43 also includes a component for providing one or more of the PRS resources to the candidate anchor UE via the SL.

45. The device according to request item 42, wherein: UE-assisted positioning for the target UE will be performed by a location server of the radio network; one or more of the PRS resources will be provided to the candidate anchor UE by a base station on a downlink (DL); one or more location measurement reports will be provided to the base station from a candidate anchor UE; one or more location measurements and measurement quality metrics from the one or more location measurement reports will be provided to the location server from the base station; and the component for selecting the at least one candidate anchor UE includes the component of the location server for selecting a candidate anchor UE as an anchor UE based on the one or more location measurements and measurement quality metrics.

46. ​​The device according to request item 40, wherein for the one or more candidate anchor UEs, each positioning measurement and associated measurement quality metric are independent of radio access technology (RAT).

47. The device according to request item 46, wherein each positioning measurement and associated measurement quality metric will be determined by the candidate anchor UE using a Global Navigation Satellite System (GNSS).

48. The device according to request item 46, wherein: The UE-based positioning will be performed by the target UE; and the one or more positioning measurements and measurement quality metrics of a candidate anchor UE will be obtained from the candidate anchor UE via a side link (SL) between the target UE and the candidate anchor UE.

49. The device according to request item 46, wherein: UE-assisted positioning of the target UE will be performed by a location server of the wireless network; one or more positioning measurements and measurement quality metrics will be provided from a candidate anchor UE to a base station; one or more positioning measurements and measurement quality metrics will be provided from the base station to the location server; and the component for selecting the at least one candidate anchor UE includes the component of the location server for selecting a candidate anchor UE as an anchor UE based on the one or more positioning measurements and measurement quality metrics.

50. The device according to claim 40 also includes a component for determining the variability of the measurement quality metrics of the plurality of candidate anchor UEs, wherein the selection of the at least one candidate anchor UE is based on the determined variability.

51. The apparatus according to claim 50, wherein the variability includes a mean and a variance of the measured quality measures.

52. The device according to request item 40, wherein the selection of the at least one candidate anchor UE is also based on the link quality of a side link (SL) between the target UE and the one or more candidate anchor UEs.

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