Location server-assisted sidelink positioning and ranging of mobile devices

Abstract

Embodiments provide enhanced procedures for mobile-originated location requests MO-LR, mobile-terminated location requests MT-LR, and periodic or triggered MT-LR that can be used to allow sidelink positioning and ranging location results to be obtained for a group of two or more UEs with assistance from an LMF (770) and provided to a group MO-LR of UEs or to an LCS client or AF for MT-LR or periodic or triggered MT-LR (775). The enhancements allow the LMF to interact with only one UE of a group of UEs (730, 725, 735, 765) and for the LCS client or AF to indicate a preference for that one UE.

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of U.S. Patent Application No. 18 / 469,547, filed September 18, 2023, entitled "SIDELINK POSITIONING AND RANGING OF MOBILE DEVICES WITH LOCATION SERVER ASSISTANCE," which in turn claims the benefit of U.S. Provisional Patent Application No. 63 / 376,437, filed September 20, 2022, entitled "SIDELINK POSITIONING AND RANGING OF MOBILE DEVICES WITH LOCATION SERVER ASSISTANCE," U.S. Provisional Patent Application No. 63 / 484,171, filed February 9, 2023, entitled "SIDELINK POSITIONING AND RANGING OF MOBILE DEVICES WITH LOCATION SERVER ASSISTANCE," and U.S. Provisional Patent Application No. 63 / 484,171, filed May 11, 2023, entitled "SIDELINK POSITIONING AND RANGING OF MOBILE DEVICES WITH LOCATION SERVER ASSISTANCE." This application claims the benefit of U.S. Provisional Patent Application No. 63 / 501,670, entitled "ASSISTANCE," all of which are assigned to the assignee of the present application and are incorporated herein by reference in their entireties. [Background technology]

[0002] 1. Field of Disclosure The present disclosure relates generally to the field of wireless communications, and more particularly to determining the location of a user equipment (UE) using measurements of radio frequency (RF) signals transmitted or modulated over a sidelink communication channel.

[0003] 2. (Description of Related Art) In wireless communication networks such as mobile / cellular broadband networks (e.g., fifth-generation (5G) wireless networks), UEs may be able to communicate with each other using sidelink (SL) communications, which are a form of wireless RF communications. Additionally, procedures may be established to allow two or more UEs to perform positioning (including ranging) using SL communications. However, many aspects of these SL-based procedures have not yet been formalized. Summary of the Invention

[0004] The present disclosure provides enhanced procedures for Mobile Originated Location Request (MO-LR), Mobile Terminated Location Request (MT-LR), and periodic or triggered MT-LR that can be used to enable sidelink positioning and ranging location results to be obtained for a group of two or more UEs with assistance from an LMF and provided to a group of UEs (MO-LR) or a Location Services (LCS) client or application function (AF) (MT-LR or periodic or triggered MT-LR). The enhanced procedures allow the LMF to interact with only one UE of a group of UEs and allow the LCS client or AF to indicate a preference for one UE.

[0005] An example method performed in a location server for supporting sidelink positioning of a plurality of user equipments (UEs) according to the present disclosure includes receiving a request for location-related information for a plurality of UEs, the request associated with a first UE of the plurality of UEs, the request being based on one of a Mobile Originated Location Request (MO-LR) sent by the first UE, or a Mobile Terminated Location Request (MT-LR) or a periodic or triggered MT-LR sent by an external client. The method further includes obtaining capability information for each UE of the plurality of UEs from the first UE of the plurality of UEs. The method further includes obtaining the location-related information. The method further includes transmitting the location-related information, where the transmitting includes one of: transmitting the location-related information to the first UE in response to the request for the location-related information being (i) based on MO-LR, where the location-related information supports sidelink positioning of the multiple UEs; or transmitting the location-related information to the external client in response to the request for the location-related information being (ii) based on MT-LR or periodic or triggered MT-LR, where the location-related information is based on sidelink positioning of the multiple UEs.

[0006] An example method performed in a first UE of a plurality of UEs to support sidelink positioning of a plurality of UEs according to the present disclosure includes performing operations including one of (i) sending a MO-LR request for location-related information toward a location server or (ii) receiving a MT-LR request or a periodic or triggered MT-LR request for location-related information from the location server, and discovering other UEs of the plurality of UEs. The method further includes obtaining capability information for each UE of the plurality of UEs. The method further includes transmitting the capability information for each UE of the plurality of UEs to the location server. The method further includes receiving a message from the location server, the message based at least in part on the capability information of each UE of the plurality of UEs. The method further includes adjusting sidelink positioning of the plurality of UEs based at least in part on the message. The method further includes obtaining location measurements, location results, or both based on the sidelink positioning of the plurality of UEs. The method further includes, when the message includes a request for location measurements or location results, sending the location measurements or location results to a location server, and the location server calculates the location result based on the location measurements when the first UE sends the location measurements to the location server.

[0007] An exemplary location server for supporting sidelink positioning of multiple user equipments (UEs) according to the present disclosure comprises one or more transceivers, one or more memories, and one or more processors communicatively coupled to the one or more transceivers and the one or more memories. The one or more processors are configured to receive, via the one or more transceivers, a request for location-related information for the multiple UEs, the request associated with a first UE of the multiple UEs, the request based on one of a mobile-originated location request (MO-LR) sent by the first UE, a mobile-terminated location request (MT-LR) sent by an external client, or a periodic or triggered MT-LR. The one or more processors are further configured to obtain capability information for each UE of the multiple UEs from the first UE of the multiple UEs via the one or more transceivers and obtain the location-related information. The one or more processors are further configured to transmit, via the one or more transceivers, the location-related information, wherein the transmitting includes one of: transmitting, to the first UE, the location-related information, where the location-related information supports sidelink positioning of the multiple UEs, in response to the request for the location-related information being (i) based on MO-LR; or transmitting, to the external client, the location-related information, where the location-related information is based on sidelink positioning of the multiple UEs, in response to the request for the location-related information being (ii) based on MT-LR or periodic or triggered MT-LR.

[0008] An exemplary first UE of a plurality of UEs for supporting sidelink positioning of a plurality of UEs according to the present disclosure comprises one or more transceivers, one or more memories, and one or more processors communicatively coupled to the one or more transceivers and the one or more memories. The one or more processors are configured to perform operations comprising one of: (i) sending a MO-LR request for location-related information toward a location server; or (ii) receiving a MT-LR request or a periodic or triggered MT-LR request for location-related information from the location server. The one or more processors are further configured to discover other UEs of the plurality of UEs. The one or more processors are further configured to obtain capability information of each UE of the plurality of UEs. The one or more processors are further configured to transmit the capability information of each UE of the plurality of UEs to the location server. The one or more processors are further configured to receive a message from the location server, the message being based at least in part on the capability information of each UE of the plurality of UEs. The one or more processors are further configured to coordinate sidelink positioning of the plurality of UEs based at least in part on the message. The one or more processors are further configured to obtain location measurements, location results, or both based on the sidelink positioning of the plurality of UEs. The one or more processors are further configured, when the message includes a request for the location measurements or the location results, to transmit the location measurements or the location results to a location server, wherein the location server calculates the location result based on the location measurements when the first UE transmits the location measurements to the location server.

[0009] This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used alone to determine the scope of the claimed subject matter. The subject matter should be understood by reference to the entire specification, any or all drawings, and appropriate portions of each claim of this disclosure. The above, together with other features and examples, are described in more detail below in the following specification, claims, and accompanying drawings. [Brief explanation of the drawings]

[0010] [Figure 1] 1 shows an architecture diagram of a communication system including several UEs, a Radio Access Network (RAN), and a 5G Core Network (5GC). [Figure 2] 1 shows the architecture of a communication system for network-supported sidelink (SL) positioning. [Figure 3] 10 is a signal flow illustrating signaling between a UE and a location server for network-supported sidelink positioning. [Figure 4A] FIG. 1 is a block diagram illustrating an implementation of a sidelink positioning protocol (SLPP) message structure. [Figure 4B] FIG. 1 is a block diagram illustrating an implementation of a sidelink positioning protocol (SLPP) message structure. [Figure 5] FIG. 10 is a signal flow diagram of an embodiment of an SLPP positioning session between UEs in UE-based or “autonomous” mode. [Figure 6] FIG. 10 is another signal flow diagram of an embodiment of an SLPP positioning session between UEs in UE-based or “autonomous” mode. [Figure 7] FIG. 10 is a signal flow diagram of a first example of an SLPP positioning session in network-assisted mode. [Figure 8]FIG. 10 is a signal flow diagram of a second example of an SLPP positioning session in network-assisted mode. [Figure 9] FIG. 10 is a signal flow diagram of a third example of an SLPP positioning session in network-assisted mode. [Figure 10] FIG. 10 is a diagram of an example sidelink positioning / ranging procedure for a group of UEs without server assistance. [Figure 11] FIG. 10 is a diagram of an example enhanced MO-LR procedure applied to a group of UEs. [Figure 12] FIG. 10 illustrates an example extended MT-LR procedure for sidelink positioning / ranging with server assistance. [Figure 13] FIG. 10 illustrates an example extended periodic or triggered MT-LR procedure for sidelink positioning / ranging with server assistance. [Figure 14] FIG. 10 illustrates an example extended periodic or triggered MO-LR procedure for sidelink positioning / ranging with server assistance. [Figure 15] FIG. 1 is a diagram of an example MT-LR procedure for ranging between target UEs. [Figure 16] FIG. 2 is a block diagram of an embodiment of a UE. [Figure 17] FIG. 1 is a block diagram of one embodiment of a computer system. [Figure 18] FIG. 10 is a diagram of an example periodic and triggered MT-LR procedure for ranging between target UEs. [Figure 19] FIG. 1 illustrates an embodiment of a method performed at a location server to support sidelink positioning of multiple UEs. [Figure 20] FIG. 1 illustrates an embodiment of a method performed in a UE to support sidelink positioning for multiple UEs.

[0011] According to some example implementations, like reference numerals in various figures refer to like elements. Additionally, multiple instances of an element may be indicated by the first numeral of that element followed by a letter or a hyphen and a second numeral. For example, multiple instances of element 110 may be indicated as 110-1, 110-2, 110-3, etc., or as 110a, 110b, 110c, etc. When referring to such an element using only the first numeral, it should be understood to refer to any instance of that element (e.g., element 110 in the previous example refers to elements 110-1, 110-2, and 110-3, or elements 110a, 110b, and 110c). Additionally, operations within some procedures shown in the figures may be indicated as numerals and referred to herein as steps (the steps may or may not be separately labeled in the figures). DETAILED DESCRIPTION OF THE INVENTION

[0012] The following description is directed to several implementations for the purposes of illustrating the inventive aspects of various embodiments, however, those skilled in the art will readily recognize that the teachings herein can be applied in many different ways. Described implementations include those based on the Institute of Electrical and Electronics Engineers (IEEE) 802.15.4 standard for ultra-wideband (UWB), the IEEE 802.11 standard (including that identified as Wi-Fi® technology), the Bluetooth® standard, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), Global System for Mobile communications (GSM), GSM / General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (W-CDMA®), Evolution Data Optimized (E-DDMA), and other standards. Optimized, EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Rate Packet Data (HRPD), High Speed ​​Packet Access (HSPA), High Speed ​​Downlink Packet Access (HSDPA), High Speed ​​Uplink Packet Access (HSUPA), Evolved High Speed ​​Packet AccessThe present invention may be implemented in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals according to any communications standard, such as any of the following: HSPA+, LTE, LTE-S, HSPA+, LTE-S ...

[0013] As used herein, an "RF signal" includes electromagnetic waves that transport information through space between a transmitter (or transmitting device) and a receiver (or receiving device). As used herein, a transmitter may transmit a single "RF signal" or multiple "RF signals" to a receiver. However, a receiver may receive multiple "RF signals" corresponding to each transmitted RF signal due to the propagation characteristics of RF signals through multiple channels or paths.

[0014] Additionally, unless otherwise specified, references to "reference signals," "positioning reference signals," "reference signals for positioning," etc. may be used to refer to signals used for positioning of user equipment (UE) in 5G New Radio (NR) networks. As described in more detail herein, such signals may include any of a variety of signal types, but may not necessarily be limited to positioning reference signals (PRS) as defined in the relevant wireless standards.

[0015] Additionally, unless otherwise specified, the term "positioning" as used herein may include absolute location determination, relative location determination, ranging, or a combination thereof. Such positioning may include and / or be based on timing, angle, phase, or power measurements, or a combination thereof (which may include RF sensing measurements), for purposes of location or sensing services.

[0016] Additionally, references herein to "TS" documents (eg, "TS 23.304") refer to the corresponding technical specifications of the 3rd Generation Partnership Project (3GPP®).

[0017] As mentioned above, SL-based signaling between two or more UEs can potentially be used to perform positioning (including ranging) of at least one of the UEs. However, many procedural aspects of such positioning have not yet been defined or formalized. Embodiments herein address these and other issues by providing enhanced procedures for mobile originated location request (MO-LR), mobile terminated location request (MT-LR), and periodic or triggered MT-LR, which can be used to enable sidelink positioning and ranging location results to be obtained for a group of two or more UEs with assistance from a location server (e.g., LMF) and provided to a group of UEs (MO-LR) or an LCS client or AF (MT-LR or periodic or triggered MT-LR). Embodiments are described after a review of the related art.

[0018] FIG. 1 illustrates an example communication system 100 including a first UE 105A, a second UE 105B, a third UE 105C, a radio access network (RAN) 135, here a fifth generation (5G) next generation (NG) RAN (NG-RAN), and a 5G core network (5GC) 140. The 5GC 140 may be, for example, a public land mobile network (PLMN). The UEs 105A, 105B, and 105C may be individually referred to as UEs 105 or collectively referred to as UEs 105 herein. The UEs 105 may be, for example, IoT devices, location tracking devices, mobile phones, vehicles, on-board units (OBUs), or other similar types of devices. The UEs 105 may also be considered roadside units (RSUs) and / or positioning reference units (PRUs) capable of supporting vehicle-to-everything (V2X) communications and procedures. The 5G network may also be referred to as a New Radio (NR) network, the NG-RAN 135 may also be referred to as a 5G RAN or an NR RAN, and the 5GC 140 may also be referred to as an NG Core network (NGC). The RAN 135 may be another type of RAN, such as a 3G RAN, a 4G Long Term Evolution (LTE) RAN, etc.The communication system 100 may utilize a constellation of satellite vehicles (SVs) 190 that may support a Satellite Positioning System (SPS) (e.g., Global Navigation Satellite System (GNSS)), such as the Global Positioning System (GPS), Global Navigation Satellite System (GLONASS), Galileo, or Beidou, or some other local or regional SPS, such as the Indian Regional Navigational Satellite System (IRNSS), the European Geostationary Navigation Overlay Service (EGNOS), or the Wide Area Augmentation System (WAAS). In some embodiments, the UE 105 may communicate with a RAN node (e.g., gNB 110) or a 5GC 140 node via the SV 190 and an earth station (not shown in FIG. 1 ), in which case the UE 105 may not communicate directly with the RAN node but only via the SV 190. This may be used to increase the coverage and / or capacity of the NG-RAN 135. Additional components of the communications system 100 are described below. The communications system 100 may include additional or alternative components.

[0019] As shown in FIG. 1 , the NG-RAN 135 includes NR NodeBs (gNBs) 110a, 110b, and a next generation eNodeB (ng-eNB) 114, and the 5GC 140 includes an Access and Mobility Management Function (AMF) 115, a Session Management Function (SMF) 117, a Location Management Function (LMF) 120, a Gateway Mobile Location Center (GMLC) 125, a Policy Control Function (PCF) 126, a Unified Data Management (UDM) 127, a User Plane Function (UPF) 118, and a Secure User Plane Location (SUPL) Location Platform (SLP) 119. The gNBs 110a, 110b, and ng-eNB 114 are communicatively coupled to each other and configured to wirelessly communicate bidirectionally with the UE 105, and are communicatively coupled to and configured to communicate bidirectionally with the AMF 115 and UPF 118. The gNBs 110a, 110b, and ng-eNB 114 may be referred to as base stations (BSs) or RAN nodes. The AMF 115, SMF 117, LMF 120, and GMLC 125 are communicatively coupled to each other, and the GMLC 125 is communicatively coupled to an external client 130, which may also be referred to as a location services (LCS) client. The AMF 115, SMF 117, UPF 118, and SLP 119 are communicatively coupled to each other, and the SLP 119 is communicatively coupled to the external client 130. According to some embodiments, server 121, Internet 122, and server 123 may be communicatively coupled to UPF 118 to facilitate SL positioning. SMF 117 may further serve as an initial point of contact for a Service Control Function (SCF) (not shown) that creates, controls, and deletes media sessions.The base stations 110a, 110b, 114 may be macrocells (e.g., high-power cellular base stations), or small cells (e.g., low-power cellular base stations), or access points (e.g., short-range base stations configured to communicate with short-range technologies such as Wi-Fi, Wi-Fi Direct (WiFi-D), BLUETOOTH, Bluetooth-low energy (BLE), ZIGBEE, etc.). One or more of the base stations 110a, 110b, 114 may be configured to communicate with the UE 105 over multiple carriers. Each of the base stations 110a, 110b, 114 may provide communication coverage for a respective geographic area, e.g., a cell. Each cell may be partitioned into multiple sectors depending on the base station antenna. The interface between the UE 105 and the gNB 110 or ng-eNB 114 may be referred to as a Uu interface, and the interface between two UEs 105 may be referred to as a sidelink or PC5 interface.

[0020] The PCF 126 may support a unified policy framework to manage network behavior, provide policy rules to the control plane function to enforce them, access subscription information related to policy decisions, and provision the necessary policies and parameters for ranging / SL positioning services to the UE 105. The policies and parameters for ranging / SL positioning services provisioned in the UE 105 may include authorization policies and parameters for ranging / SL positioning via PCF 126, authorization policies and parameters for network-based SL positioning, and authorization policies and parameters for network-assisted SL positioning and ranging / SL positioning service exposure.

[0021] The UDM 127 may support generation of UE authentication credentials, user identification processing (e.g., storage and management of the Subscription Persistent Identifier (SUPI) and GPSI for each UE), deciphering of the Privacy Protected Subscription Identifier (SUCI), access authorization based on subscription data (e.g., roaming restrictions), subscription management, and mobility management (e.g., by storing the current Serving AMF and Serving PLMN identity for each subscribed UE).

[0022] 1 provides a generalized illustration of various components, any or all of which may be utilized as appropriate, and each of which may be duplicated or omitted as desired. In particular, while only the UE 105 is illustrated, many UEs (e.g., hundreds, thousands, millions, etc.) may be utilized in the communications system 100. Similarly, the communications system 100 may include many more (or fewer) SVs (i.e., more or fewer than the four SVs 190 shown), gNBs 110a, 110b, ng-eNB 114, AMF 115, external clients 130, and / or other components. The connections shown connecting the various components in the communications system 100 include data and signaling connections, which may include additional (intermediate) components, direct or indirect physical and / or wireless connections, and / or additional networks. Furthermore, components may be rearranged, combined, separated, substituted, and / or omitted depending on the desired functionality.

[0023] 1 shows a 5G-based network, similar network implementations and configurations may be used for other communication technologies such as 3G, Long Term Evolution (LTE), etc. Implementations described herein (whether for 5G technology and / or for one or more other communication technologies and / or protocols) may be used to transmit (or broadcast) directional synchronization signals, receive and measure the directional signals at a UE (e.g., the UE 105) or base station 110a, 110b, 114, and / or provide location assistance to the UE 105 (via the LMF 120 or SLP 119 or other location server), and / or calculate the location of one or both of the UEs 105 at a location-enabled device such as the UE 105, base station 110a, 110b, LMF 120, or SLP 119 based on measurements received at the UE 105 or base station 110a, 110b, 114 of such directionally transmitted signals. The GMLC 125, LMF 120, AMF 115, SMF 117, UPF 118, SLP 119, ng-eNB (eNodeB) 114, and gNBs (gNodeBs) 110a, 110b are examples and may be replaced by or include various other entities, including location server functionality and / or base station functionality, in various embodiments.

[0024] The communications system 100 is capable of wireless communications in that components of the system 100 may communicate with one another (at least sometimes using wireless connections) directly or indirectly, e.g., via the base stations 110a, 110b, 114 and / or the network 140 (and / or one or more other devices, not shown, such as one or more other base transceiver stations). In the case of indirect communications, communications may be altered during transmission from one entity to another, e.g., to alter header information of data packets, to change formatting, etc. The UE 105 may include multiple UEs and may be a mobile wireless communications device, but may communicate wirelessly and via wired connections. The UE 105 may be any of a variety of devices, e.g., a smartphone, a tablet computer, a vehicle-based device, etc., although these are merely examples and other configurations of UEs may be used, as the UE 105 is not required to be any of these configurations. Other UEs may include wearable devices (e.g., a smart watch, smart jewelry, smart glasses, or a headset, etc.). Still other UEs, whether currently existing or developed in the future, may be used. Additionally, other wireless devices (whether mobile or not) may be implemented within system 100 and may communicate with each other and / or with UE 105, base stations 110a, 110b, 114, core network 140, and / or external client 130. For example, such other devices may include IoT or Industrial Internet of Things (IIoT) devices, medical devices, home entertainment and / or automation devices, etc. Core network 140 may communicate with external client 130, server 123, or server 121 (e.g., each of which may be a computer system) to, for example, enable external client 130, server 123, or server 121 to request and / or receive location information regarding UE 105 (e.g., via GMLC 125, SLP 119, or UPF 118).

[0025] The UE 105 or other device may be configured to communicate in different networks and / or for different purposes and / or using different technologies (e.g., 5G, Wi-Fi communications, multiple frequencies of Wi-Fi communications, satellite positioning, satellite communications, one or more types of communications (e.g., Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Long Term Evolution (LTE)), V2X (e.g., V2P (Vehicle-to-Pedestrian), V2I (Vehicle-to-Infrastructure), V2V (Vehicle-to-Vehicle), etc.), IEEE 802.11p, etc.). V2X communications may be implemented using cellular (Cellular-V2X, C-V2X) and / or Wi-Fi (e.g., Dedicated Short-Range Radio Communication (DSRC)). The system 100 may be a dedicated short-range connection. The system 100 may support operation on multiple carriers (waveform signals at different frequencies). A multi-carrier transmitter can simultaneously transmit modulated signals on multiple carriers. Each modulated signal may be a Code Division Multiple Access (CDMA) signal, a Time Division Multiple Access (TDMA) signal, an Orthogonal Frequency Division Multiple Access (OFDMA) signal, a Single-Carrier Frequency Division Multiple Access (SC-FDMA) signal, etc. Each modulated signal may be sent on a different carrier and may carry pilot, overhead information, data, etc.The UEs 105 may communicate with each other via UE-to-UE sidelink (SL) communication by transmitting on one or more sidelink channels, such as a physical sidelink synchronization channel (PSSCH), a physical sidelink broadcast channel (PSBCH), a physical sidelink control channel (PSCCH), a synchronization signal block (SSB), a sidelink channel state information reference signal (SL-CSIRS), a physical sidelink feedback channel (PSFCH), or a sidelink sounding reference signal (SL-SRS).

[0026] The UE 105 may include and / or be referred to as a device, a mobile device, a wireless device, a mobile terminal, a terminal, a mobile station (MS), a Secure User Plane Location (SUPL) Enabled Terminal (SET), or by some other name. Furthermore, the UE 105 may correspond to a cell phone, a smartphone, a laptop, a tablet, a PDA, a tracking device, a navigation device, an Internet of Things (IoT) device, an asset tracker, a health monitor, a security system, a smart city sensor, a smart meter, a wearable tracker, or some other portable or movable device. Typically, although not necessarily, the UE 105 may support wireless communications using one or more radio access technologies (RATs), such as Global System for Mobile communications (GSM), Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), LTE, High Rate Packet Data (HRPD), IEEE 802.11 Wi-Fi (also referred to as Wi-Fi), Bluetooth (BT), Worldwide Interoperability for Microwave Access (WiMAX), 5G New Radio (NR) (e.g., using NG-RAN 135 and 5GC 140), etc. The UE 105 may support wireless communications using, for example, a wireless local area network (WLAN), which may connect to other networks (e.g., the Internet) using a Digital Subscriber Line (DSL) or packet cable.Use of one or more of these RATs may enable UE 105 to communicate with external client 130, server 121, and / or server 123 (e.g., via elements of 5GC 140 and possibly the Internet 122) and / or enable external client 130, server 121, and / or server 123 to receive location-related information regarding UE 105 (e.g., via GMLC 125, SLP 119, or UPF 118).

[0027] Each UE 105 may comprise a single entity or may comprise multiple entities, such as in a personal area network where a user may employ audio, video, and / or data I / O (input / output) devices and / or body sensors and a separate wireline or wireless modem. An estimate of a UE, e.g., UE 105 location, may be referred to as a location, location estimate, location fix, fix, position, position estimate, or position fix, and may be geographic and thus provide location coordinates (e.g., latitude and longitude) of the UE that may or may not include an altitude component (e.g., height above sea level, height or depth above ground, floor level, or basement level). Alternatively, the UE location may be expressed as a civic location (e.g., as a postal address or as a designation of some point or small area in a building, such as a particular room or floor). The UE location may be expressed as an area or volume (defined either geodesically or urbanically) within which the UE is expected to be located with some probability or confidence level (e.g., 67%, 95%, etc.). The location of a UE may be expressed as a relative location comprising, for example, a distance and a direction from a known location. The relative location may be expressed as relative coordinates (e.g., X, Y (and Z) coordinates) defined relative to some origin in the known location, which may be defined, for example, geodesically, in terms of cities, or by reference to a point, area, or volume shown on a map, floor plan, or building plan. In the description contained herein, use of the term location may include any of these variations unless otherwise indicated.

[0028] When sidelink positioning is used, an absolute (e.g., global) or relative location of the UE may not always be obtained. Instead, location results may be obtained for the UE, which may include the range or distance between the UE and each of one or more other UEs, the direction from the UE to each of the one or more other UEs, the location of the UE relative to the locations of some other UEs, the locations of one or more other UEs relative to the UE's location, the velocity of the UE, and / or the velocity of each of the one or more other UEs. The velocity of a UE may be absolute (e.g., with respect to the Earth) or relative to some other UE and may be referred to as the "relative velocity." The relative velocity of UE B with respect to another UE A may include a "radial velocity" component, which may be equal to the rate of change of range from UE A to UE B, and a "lateral velocity" component, which may be orthogonal to the radial velocity component from the perspective of UE A and may be equal to the angular rate of change of the direction from UE A to UE B multiplied by the range from UE A to UE B. In the description contained herein, the use of the term "location result(s)" for sidelink positioning of a UE or group of UEs may include any of these variations, unless otherwise indicated.

[0029] The UE 105 may be configured to communicate with other entities using one or more of a variety of technologies. The UE 105 may be configured to communicate with one or more other UEs (e.g., other UEs 105) via one or more device-to-device (D2D) peer-to-peer (P2P) links. A D2D P2P link may be an example of (or may be supported by) a sidelink and may be supported using any suitable D2D radio access technology (RAT), such as LTE Direct (LTE-D), Wi-Fi Direct (Wi-Fi D), Bluetooth, etc. One or more of a group of UEs utilizing D2D communication may be within the geographic coverage area of ​​a Transmission / Reception Point (TRP), such as one or more of the gNBs 110a, 110b, and / or ng-eNB 114. Other UEs in such a group may be outside such geographic coverage area or may otherwise be unable to receive transmissions from the base station. A group of UEs communicating via D2D communication may utilize a one-to-many (1:M) system in which each UE may transmit to other UEs in the group. The TRP may facilitate scheduling of resources for D2D communication. In other cases, D2D communication may be performed between UEs without the involvement of a TRP. One or more of a group of UEs utilizing D2D communication may be within a geographic coverage area of ​​a TRP. Other UEs in such a group may be outside such geographic coverage area or may otherwise be unable to receive transmissions from a base station. A group of UEs communicating via D2D communication may utilize a one-to-many (1:M) system in which each UE may transmit to other UEs in the group. The TRP may facilitate scheduling of resources for D2D communication. In other cases, D2D communication may be performed between UEs without the involvement of a TRP.

[0030] The base stations (BSs) in the NG-RAN 135 shown in FIG. 1 include NR Node Bs referred to as gNBs 110a and 110b. The pair of gNBs 110a, 110b in the NG-RAN 135 may be connected to each other through one or more other gNBs. Access to the 5G network is provided to the UE 105 via wireless communication between the UE and one or more of the gNBs 110a, 110b, and the gNBs 110a, 110b may provide wireless communication access to the 5G Grid Control System 140 for UEs using 5G. In FIG. 1, the serving gNB for UE 105A is assumed to be gNB 110b, while the serving gNB for UE 105B is assumed to be gNB 110a; however, another gNB may serve as the serving gNB if the UE 105 moves to another location, or may serve as a secondary gNB to provide additional throughput and bandwidth to the UE 105, and the UEs 105 may share the same serving gNB.

[0031] 1 may include the ng-eNB 114, also referred to as a next generation evolved Node B. The ng-eNB 114 may be connected to one or more of the gNBs 110a, 110b in the NG-RAN 135, possibly via one or more other gNBs and / or one or more other ng-eNBs. The ng-eNB 114 may provide LTE wireless access and / or evolved LTE (eLTE) wireless access to the UE 105. One or more of the gNBs 110a, 110b and / or ng-eNB 114 may be configured to function as positioning-only beacons, which may transmit signals to assist in determining the location of the UE 105 but may not receive signals from the UE 105 or from other UEs.

[0032] The base stations 110a, 110b, 114 may transmit one or more downlink reference signals, including positioning reference signal (PRS) transmissions. The PRS transmissions may be configured for a particular UE 105 to measure and report one or more reporting parameters (e.g., reporting quantities) associated with positioning and location information. The PRS transmissions and reporting parameter feedback may support various location services (e.g., navigation systems, emergency communications). In some examples, the reporting parameters augment one or more additional location systems (e.g., Global Positioning System (GPS) technology) supported by the UE 105.

[0033] The base station 110a, 110b, 114 may configure PRS transmissions on one or more PRS resources of a channel. A PRS resource may span resource elements of multiple physical resource blocks (PRBs) within one or more OFDM symbols of a slot, depending on the configured number of ports. For example, a PRS resource may span one symbol of a slot and include one port for transmission. In any OFDM symbol, a PRS resource may occupy consecutive PRBs. In some examples, PRS transmissions may be mapped to consecutive OFDM symbols of a slot. In other examples, PRS transmissions may be mapped to interspersed OFDM symbols of a slot. Additionally, PRS transmissions may support frequency hopping within a PRB of a channel.

[0034] One or more PRS resources may span several PRS resource sets according to the PRS resource configuration of the base station 110 a, 110 b, 114. The structure of one or more PRS resources, PRS resource sets, and PRS resource configurations within a PRS transmission may be referred to as a multi-level resource configuration. For example, the multi-level PRS resource configuration of the base station 110 a, 110 b, 114 may include multiple PRS resource sets, and each PRS resource set may include a set of PRS resources (such as a set of four PRS resources).

[0035] The UE 105 may receive a PRS transmission via one or more PRS resources of the slot. The UE 105 may determine at least one reporting parameter for some of the PRS resources included in the transmission. The reporting parameter (which may include a reporting quantity) for each PRS resource may include one or more of a time of arrival (TOA), a reference signal time difference (RSTD), a reference signal receive power (RSRP), an angle, a PRS identification number, a receive-to-transmit difference (UE Rx-Tx), a signal-to-noise ratio (SNR), or a reference signal receive quality (RSRQ).

[0036] Similarly, the UE 105 may be configured to transmit one or more additional uplink reference signals that can be received by the base stations 110a, 110b, 114 and used for positioning. For example, the UE 105 may transmit a sounding reference signal (SRS) for positioning. The base stations 110a, 110b, 114 that receive the uplink reference signals from the UE 105 may perform positioning measurements such as one or more of a time of arrival (TOA), a difference between receive and transmit (UE Rx-Tx), etc.

[0037] A UE's position estimate may be determined using reference signals, such as PRS or SRS for positioning signals or other reference signals from one or more base stations 110a, 110b, 114 or the UE. Positioning methods such as downlink (DL) time difference of arrival (DL-TDOA), DL angle of departure (DL AOD), and enhanced cell ID (ECID) are positioning methods that may be used to estimate a UE's position using reference signals from base stations. For example, DL-TDOA relies on measuring reference signal time differences (RSTDs) between downlink (DL) signals received from a base station for a reference cell and DL signals received from base stations for one or more neighboring cells. DL signals from which RTSDs may be obtained comprise cell-specific reference signals (CRS) and positioning reference signals (PRS).

[0038] Other positioning methods may use reference signals transmitted by the UE, including uplink-based positioning methods and downlink-and-uplink-based positioning methods. For example, uplink-based positioning methods include, for example, UL Time Difference of Arrival (UL-TDOA), UL Angle of Arrival (UL AOA), and UL Relative Time of Arrival (UL-RTOA), while downlink-and-uplink-based positioning methods include, for example, multi-cell round trip time (RTT) with one or more neighboring base stations. In addition, sidelink-based positioning may be used, in which the UE transmits and / or receives sidelink positioning reference signals that are measured and used for positioning.

[0039] As noted, while FIG. 1 illustrates nodes configured to communicate according to a 5G communication protocol, nodes configured to communicate according to other communication protocols, such as, for example, an LTE protocol or an IEEE 802.11x protocol, may also be used. For example, in an Evolved Packet System (EPS) providing LTE wireless access to the UE 105, the RAN may include an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), which may include base stations including evolved Node Bs (eNBs). The core network for the EPS may comprise an Evolved Packet Core (EPC). The EPS may include the E-UTRAN plus the EPC, where in FIG. 1, the E-UTRAN corresponds to the NG-RAN 135 and the EPC corresponds to the 5GC 140.

[0040] The gNBs 110a, 110b, and ng-eNBs 114 may communicate with the AMF 115, which in turn communicates with the LMF 120 for positioning functions. The AMF 115 may support mobility of the UE 105, including cell changes and handovers, and may be responsible for supporting signaling connections to the UE 105 and possibly data and voice bearers for the UE 105. The LMF 120 may communicate directly or indirectly with the UE 105 or with the base stations 110a, 110b, 114, for example, via wireless communication. The LMF 120 may support positioning of the UE 105 when the UE 105 accesses the NG-RAN 135 and may support positioning procedures / methods such as Assisted GNSS (A-GNSS), Time Difference of Arrival (TDOA) (e.g., downlink (DL) TDOA or uplink (UL) TDOA), Real Time Kinematic (RTK), Precise Point Positioning (PPP), Differential GNSS (DGNSS), Extended Cell ID (E-CID), Angle of Arrival (AOA), Angle of Departure (AOD), and / or other positioning methods. The LMF 120 may process location service requests for the UE 105, for example, received from the AMF 115 or from the GMLC 125. The LMF 120 may be connected to the AMF 115 and / or to the GMLC 125. A node / system running LMF 120 may additionally or alternatively run other types of location support modules, such as an Enhanced Serving Mobile Location Center (E-SMLC) or a Secure User Plane Location (SUPL) Location Platform (SLP).At least a portion of the positioning functionality (including derivation of the UE's location) may be performed in the UE (e.g., using signal measurements obtained by the UE due to signals transmitted by wireless nodes such as the gNBs 110a, 110b and / or the ng-eNB 114 and / or assistance data provided to the UE by the LMF 120, for example). At least a portion of the positioning functionality (including derivation of the UE's location) may alternatively be performed in the LMF 120 (e.g., using signal measurements obtained by the gNBs 110a, 110b and / or the ng-eNB 114). The AMF 115 may act as a control node that handles signaling between the UE 105 and the core network 140 and provides quality of service (QoS) flow and session management. The AMF 115 may support the mobility of the UE 105, including cell changes and handovers, and may be responsible for supporting signaling connections to the UE 105.

[0041] The GMLC 125 may support location requests for the UE 105 received from the external client 130 and may forward such location requests to the AMF 115 for forwarding by the AMF 115 to the LMF 120, or may forward the location request directly to the LMF 120. A location response from the LMF 120 (e.g., including a location estimate or sidelink location result for the UE 105) may be returned to the GMLC 125 either directly or via the AMF 115, which may then return a location response (e.g., including the location estimate or sidelink location result) to the external client 130. Although the GMLC 125 is shown as connected to both the AMF 115 and the LMF 120, in some implementations, only one of these connections may be supported by the 5GC 140. A GMLC can operate as a Home GMLC (H-GMLC) when located in the home PLMN for a target UE, or as a Visited GMLC (V-GMLC) when located in the serving PLMN for a target UE, or as both an H-GMLC and a V-GMLC when located in the home PLMN for a non-roaming target UE. The terms (H)GMLC or GMLC may be used to refer to a GMLC that operates as an H-GMLC and can also operate as a V-GMLC.

[0042] The user plane function (UPF) 118 may support voice and data bearers for the UE 105 and enable voice and data access for the UE 105 to other networks, such as the Internet 122, and servers, such as server 121 and server 123. The UPF 118 may be connected to the gNB 110 and the ng-eNB 114. The functions of the UPF 118 may include external Protocol Data Unit (PDU) session points for interconnection to data networks, packet (e.g., Internet Protocol (IP)) routing and forwarding, the user plane portion of packet inspection and policy rule enforcement, Quality of Service (QoS) handling for the user plane, downlink packet buffering, and triggering of downlink data notifications. The UPF 118 may be connected to the SLP 119 to enable support for positioning of the UE 105 using SUPL. The SLP 119 may further be connected to or accessible by the external client 130.

[0043] As shown, a session management function (SMF) 117 connects the AMF 115 and the UPF 118. The SMF 117 may have the ability to control both the local UPF and the central UPF within a PDU session. The SMF 117 may manage the establishment, modification, and release of PDU sessions for the UE 105, perform IP address allocation and management for the UE 105, act as a Dynamic Host Configuration Protocol (DHCP) server for the UE 105, and select and control the UPF 118 for the UE 105.

[0044] 1, the LMF 120 may communicate with the gNBs 110a, 110b, and / or the ng-eNB 114 using the New Radio Position Protocol A (NRPPa), which may be defined in 3GPP Technical Specification (TS) 38.455. NRPPa messages may be transferred between the gNB 110a (or gNB 110b) and the LMF 120 and / or between the ng-eNB 114 and the LMF 120 via the AMF 115. As further shown in FIG. 1, the LMF 120 and the UE 105 may communicate using the LTE Positioning Protocol (LPP), which may be defined in 3GPP TS 37.355. Here, LPP messages may be transferred between the UE 105 and the LMF 120 via the AMF 115 and the serving gNB 110a, 110b, or serving ng-eNB 114 for the UE 105. For example, LPP messages may be transferred between the LMF 120 and the AMF 115 using service operations based on the Hypertext Transfer Protocol (HTTP), and may be transferred between the AMF 115 and the UE 105 using 5G Non-Access Stratum (NAS) protocols.

[0045] The LPP protocol may be used to support positioning of the UE 105 using UE-assisted and / or UE-based positioning methods, such as A-GNSS, RTK, TDOA, AOA, AOD, and / or E-CID. The NRPPa protocol may be used to support positioning of the UE 105 using network-based positioning methods, such as E-CID (e.g., when used in conjunction with measurements obtained by the gNBs 110a, 110b, or ng-eNB 114), and / or may be used by the LMF 120 to obtain location-related information from the gNBs 110a, 110b, and / or ng-eNB 114, such as parameters defining directional synchronization signal (SS) transmissions from the gNBs 110a, 110b, and / or ng-eNB 114. While the LMF 120 is shown in FIG. 1 as being located in the core network 140, it may also be outside the core network 140, e.g., in the NG-RAN. For example, the LMF120 may be co-located or integrated with the gNB, or may be located remotely from the gNB, and may be configured to communicate directly or indirectly with the gNB.

[0046] In a UE-assisted positioning method, a UE, e.g., UE 105A or UE 105B, may obtain location measurements and send the measurements to a location server (e.g., LMF 120) for calculation of a location estimate for the UE. For example, the location measurements may include one or more of a Received Signal Strength Indication (RSSI), a Round Trip Signal Propagation Time (RTT), a Reference Signal Time Difference (RSTD), a Reference Signal Received Power (RSRP) and / or a Reference Signal Received Quality (RSRQ), an AOA, and an AOD for the gNB 110a, 110b, the ng-eNB 114, and / or a WLAN AP. The location measurements may also or instead include measurements of GNSS pseudorange, code phase, and / or carrier phase for SV190.

[0047] In a UE-based positioning method, a UE, for example, UE 105A or UE 105B, may obtain location measurements (which may, for example, be the same as or similar to location measurements for a UE-assisted positioning method) and may calculate the location of the UE (e.g., with the help of assistance data received from a location server such as LMF 120 or broadcast by gNB 110a, 110b, ng-eNB 114, or other base station or AP).

[0048] In a network-based positioning method, one or more base stations (e.g., gNBs 110a, 110b, and / or ng-eNB 114) may obtain location measurements (e.g., RSSI, RTT, RSRP, RSRQ, AOA, AOD, or Time of Arrival (ToA) measurements for signals transmitted by a UE, e.g., UE 105A or UE 105B) and / or may receive measurements obtained by the UE. One or more base stations or APs may send the measurements to a location server (e.g., LMF 120) for calculation of a location estimate for the UE.

[0049] As mentioned, although the communications system 100 is described with respect to 5G technology, the communications system 100 may be implemented to support other communications technologies, such as GSM, WCDMA, LTE, etc., used to support and interact with mobile devices such as the UEs 105 (e.g., to perform voice, data, positioning, and other functions). For example, in an EPS, the NG-RAN 135 may be replaced with an E-UTRAN including an eNB, and the 5GC 140 may be replaced with an EPC including a Mobility Management Entity (MME) in place of the AMF 115, an E-SMLC in place of the LMF 120, and a GMLC, which may be similar to the GMLC 125.

[0050] Positioning for a UE in a wireless network, such as the communication system 100 shown in FIG. 1, typically uses the Uu interface, i.e., the air interface between the UE 105 and the radio access network, for DL ​​PRS and / or UL PRS. Positioning for a UE may also, or instead, use sidelink PRS (SL-PRS), which may be a specific sidelink-defined reference signal for positioning, or may reuse Uu PRS, e.g., UL PRS, sometimes referred to as Sounding Reference Signals for positioning (SRSPos), or other reference signals may be transmitted in the sidelink channel. Sidelink positioning may extend UE positioning by providing additional transmitting (or receiving) nodes. A UE, such as UE 105B, with a known location may be used to support the position determination of another target UE, such as UE 105A, and UE 105B may be referred to as an anchor node.

[0051] Using the sidelink positioning method, the UE 105A may transmit, for example, a sidelink PRS or sidelink SRS signal to be received and measured by another UE 105B. Additionally or alternatively, the UE 105B may transmit, for example, a sidelink PRS or sidelink SRS signal to be received and measured by the UE 105A. The sidelink PRS may be similar to the PRS (e.g., DL PRS) transmitted by the gNB 110, for example, as described above. The sidelink SRS may be similar to the SRS (e.g., uplink) transmitted by the UE 105 for measurement by the gNB 110, for example, as described above. Measurements of the SL PRS or SL SRS signal may include reception to transmission time difference (Rx-Tx), time of arrival (TOA), reference signal received power (RSRP), reference signal received quality (RSRQ), angle of arrival (AOA), and reference signal time difference (RSTD). SL positioning methods may include SL round trip signal propagation time (RTT) (also called ranging), SL AOA, SL AOD, or any combination thereof.

[0052] In some scenarios, a group of UEs (not shown in FIG. 1 ) may support SL positioning. In this case, one UE in the group may transmit an SL PRS or SL SRS signal that can be measured by some or all of the other UEs in the group. Some or all of the other UEs in the group may also transmit an SL PRS or SL SRS signal, respectively, that can be measured by some or all of the other UEs in the group differently from the UE transmitting the UL PRS or UL SRS (e.g., each UE transmits the SL SRS or SL PRS at one or more times different from the times at which other UEs in the group transmit the SL PRS or SL SRS). Measurements made by the UEs applicable to the SL PRS or SL SRS transmission by the group of UEs may include Rx-Tx, TOA, RSTD, AOA, RSRP, RSRQ, or any combination thereof. Positioning methods supported by these measurements may include sidelink RTT (e.g., ranging), sidelink AOA, sidelink AOD, sidelink TDOA (SL-TDOA), or any combination thereof. Based on the measurements and the positioning method(s), each UE may determine a location result for itself and / or one or more other UEs in the group. As mentioned above, the location result for a UE may include the range or distance between the UE and each of the one or more other UEs in the group, the direction from the UE to each of the one or more other UEs in the group, the direction from each of the one or more other UEs in the group to the UE, the location of the UE relative to the locations of any other UEs in the group, the location of the UE relative to some other known location, the absolute location of the UE, the velocity of the UE, or the velocity of the UE relative to some other UEs.

[0053] Sidelink positioning can be used for positioning a UE independent of the core network (e.g., 5GC 140) or the serving PLMN. One example implementation of sidelink positioning can be found in vehicular communication systems such as V2X, which can be used for safety-related applications such as safety warnings, traffic congestion (e.g., automated traffic control), and cooperative or automated vehicle steering. One aspect of sidelink positioning that may require a standardization solution is the Sidelink Positioning Protocol (SLPP), which can be used between a UE and a location server, including between an RSU and a UE. SLPP can support sidelink positioning, for example, between a UE, an RSU, and a PRU with network access independence. SLPP can provide support for sidelink positioning for pairs of UEs (e.g., ranging), groups of UEs (V2X), and UEs that are members of multiple different groups. For example, SLPP may provide support for various positioning techniques currently standardized for UE-based and UE-assisted support by location servers (e.g., LMF 120), such as PRS RTT, AOA, Differential AOA (DAOA), AOD, and Differential AOD (DAOD), but may also enable support for other PRS- and SRS-based positioning methods and, later, non-PRS methods such as RTK. By allowing the addition of new capabilities and methods later, SLPP may avoid the need to define a new positioning protocol separate from SLPP. For example, additional positioning methods that may later be included in SLPP may include RTK, Wi-Fi, Ultra-Wideband (UWB), and Bluetooth positioning methods. SLPP may initially enable direct sidelink operation (UEs communicate and coordinate positioning by exchanging SLPP messages using sidelink signaling) and may later be extended to sidelink operation via relays and network-mediated operation, where UEs may exchange SLPP messages via the network or via intermediate relay UEs.For example, this may be used to coordinate the positioning of two vehicles on a collision course at a corner where direct SL signaling between the two vehicles is not possible. Therefore, SLPP may initially define support for SL PRS-based positioning in a general manner to simplify later extension to support for other positioning methods. For example, SLPP may define general SLPP messages similar to the general LPP messages defined for LPP in 3GPP TS 37.355. SLPP may support distinct positioning methods (e.g., SL PRS RTT, SL PRS AOA, SL PRS AOD) using common procedures and common parameters, where feasible. SLPP may define procedures that can be reused for multiple positioning methods and is not limited to just one or a few positioning methods. SLPP may be enabled to be transferred and used by various entities, such as UEs, RSUs, PRUs, and location servers such as LMFs and SUPL SLPs. Location server (e.g., LMF and SUPL SLP) uses may forward SLPP messages within LPP messages to enable UE-assisted positioning by the LMF or SUPL SLP. Alternatively, location server (e.g., LMF and SUPL SLP) uses may forward SLPP messages that are not associated with LPP messages to enable UE-assisted positioning by the LMF or SUPL SLP. SLPP may further support relative (local) and global positioning.

[0054] As used herein, the term "target UE" may refer to a UE for which a location result is desired. When a group of two or more UEs participates in SL positioning, only some of the group of UEs may be target UEs, since location results may already be known or may not be needed for other UEs. However, for generality, when describing the techniques described herein for positioning a group of UEs, all of the UEs may potentially be considered target UEs, since there may be little or no difference in how the techniques described herein are used for positioning.

[0055] FIG. 2 illustrates, by way of example, the architecture of a communication system 200 capable of network-supported sidelink positioning. As illustrated in FIG. 2, several UEs may be combined into the same group 210 for sidelink positioning. Within the group 210, there may be various subgroups of UEs. For example, the group 210 of UEs may include a first subgroup 212 of UEs served by a first network (PLMN1 140a), a second subgroup 214 of UEs served by a second (different) network (PLMN2 140b), and a third subgroup 216 of UEs that are out of coverage and not served by either network. One or more of the UEs served by the network, e.g., the UEs in the subgroup 212 served by PLMN1 140a or the UEs in the subgroup 214 served by PLMN2 140b, may include RSUs.

[0056] Location servers in the serving networks, e.g., LMF1 120a, SUPL SLP1 119a, or Server 1 121a in serving PLMN1 140a, LMF2 120b, SUPL SLP2 119b, or Server 2 121b in serving PLMN2 140b, and Server 3 123 (which communicates to the UEs via PLMN1 140a and / or PLMN2 140b), may support some or all UEs in a group served by the network (PLMN), e.g., subgroups 212 and 214, respectively. As shown, the location servers may support the UEs by communicating with the UEs using "LPP / SLPP," which refers to communicating using LPP, SLPP, embedding SLPP in LPP, or a combination thereof. For example, LMF1 120a and LMF2 120b may embed SLPP in the LPP while supporting UEs in subgroups 212 and 214, respectively (e.g., each SLPP message transferred between a UE and LMF1 120a or LMF2 120b may be embedded in one LPP message, and one LPP message may contain one or more embedded SLPP messages). Similarly, SUPL SLP1 119a and SUPL SLP2 119b may embed SLPP in the LPP using LPP messages embedded in SUPL User Plane Location Protocol (ULP) messages while supporting UEs in subgroups 212 and 214, respectively. Additionally or alternatively, LPP and / or SLPP messages may be used, with SLPP messages not embedded in LPP messages (although LPP or SLPP messages may still be embedded in SUPL ULP messages). Additionally, UEs in each subgroup, and UEs in different subgroups, may exchange SLPP messages with each other to support and coordinate SL positioning.

[0057] Location server (e.g., LMF / SUPL SLP / Server1 / Server2 / Server3) support for a particular UE or UEs may not be visible to other UEs in the group. For example, location server support from PLMN1 140a for UEs in subgroup 212 may not be visible to UEs in subgroup 214, and may not be visible to out-of-coverage UEs in subgroup 216. The support provided by the location server to the UEs may include determining or verifying SL PRS configurations and calculating location results for UEs, including supported and unsupported UEs (e.g., calculating location results for UEs in the supported subgroup and, if location information for UEs in the unsupported subgroup is provided to the location server, location results for UEs in the unsupported subgroup). In some implementations, signaling between location servers in separate networks can be used to provide more complete network support. As shown, LMF-LMF or SUPL SLP-SUPL SLP signaling may be used (e.g., SLPP in FIG. 2) to enable more complete network support. ** An extension to SLPP (called

[0058] SLPP message types may be consistent with LPP message types to allow LPP messages to include embedded SLPP messages and / or to allow SLPP procedures to be consistent with LPP procedures, which may reduce implementation and / or testing. Figure 2 shows signaling (e.g., SLPP messages or SLPP messages embedded in LPP messages) between LMF1 120a and one or more of the UEs in subgroup 212, and signaling between LMF2 120b and one or more of the UEs in subgroup 214. Figure 2 also shows LPP messages, or LPP messages including embedded SLPP messages, embedded in SUPL ULP messages exchanged between SUPL SLP1 119a and one or more of the UEs in subgroup 212, and between SUPL SLP2 119b and one or more of the UEs in subgroup 214. SLPP may include messages similar to the LPP capability request and capability provision messages, which may be referred to, for example, in SLPP as "capability and resource requests" and "capability and resource provision." Capability and resource requests / provisions in SLPP may initially be limited to NR SL PRS capabilities and resources, but may later be expanded to capabilities and resources for LTE SL PRS, RTK, Wi-Fi, BT, etc.

[0059] In another example, SLPP may include messages similar to the LPP Provide Assistance Data message, which may be referred to, for example, in SLPP as "Provide Positioning Signal Configuration" (or simply as "Provide Assistance Data"). A positioning signal configuration provide in SLPP may include, for example, one or more of the SL PRS configurations to be transmitted by each UE and measured by other UEs, the start time and duration of transmission and the condition for the end of transmission, and the type of SL PRS measurement requested, such as Rx-Tx, AOA, RSRP, RSRD, TOA, TDOA, etc. In some implementations, a positioning signal configuration provide in SLPP may be extended to define other types of signals, such as RTK signals to be measured, Wi-Fi signals to be transmitted and measured, etc. A positioning signal configuration provide in SLPP may include additional information, for example, to assist the UE in acquiring and measuring signals (e.g., SL PRS signals) and to determine the times of transmission and measurement.

[0060] In another example, SLPP may include messages such as "Confirm Positioning Signal Configuration" (or "Provide Assistance Data Confirm"), which do not have an analogous LPP message. The positioning signal configuration confirm in SLPP may, for example, confirm whether the positioning signal configuration provision (or assistance data provision) is agreeable. If the positioning signal configuration provision is not (partially) agreeable, a different configuration may be provided as the positioning signal configuration provision. Since LPP does not have an analogous message, a new LPP message type may be added to carry the positioning signal configuration confirm SLPP message when SLPP messages are embedded in LPP messages. However, such a new LPP message type may not be needed when SLPP messages are not embedded in LPP messages.

[0061] In another example, SLPP may include messages similar to LPP Provide Location Information messages, which may be referred to, for example, as "Provide Location Information" messages in SLPP. Provide Location Information messages in SLPP may include and provide SL PRS measurements obtained by the UE for SL PRS transmitted by one or more other UEs and / or may include and provide location results obtained for the UE and / or other UEs. Provide Location Information in SLPP may be extended to include and provide other measurements, such as measurements of RTK, Wi-Fi, BT, etc.

[0062] As shown in FIG. 2 , UEs in each subgroup and UEs in different subgroups may signal each other using SLPP (e.g., when a UE sends an SLPP message to one or more other UEs). In addition, a location server (e.g., an LMF, a SUPL SLP, or Servers 1-3) may support UEs using SLPP (as described above). As previously mentioned, according to some embodiments, SLPP may be embedded in LPP, or embedded in both LPP and SUPL, or may be transmitted without being embedded in LPP. Thus, a first UE may receive a first SLPP message from a second UE and may send the first SLPP message to a location server supporting the first UE. The first UE may receive a second SLPP message from the location server in response to the first SLPP message and may send the second SLPP message to the second UE.

[0063] Figure 3 is a signal flow 300 illustrating signaling between UE 105A, UEs 105B, 105C, and 105D, and a location server 302 for network-supported sidelink positioning as described herein, by way of example. UEs 105A, 105B, 105C, and 105D may belong to the same group, e.g., UE 105 shown in Figure 1, or any of the UEs shown in network-supported subgroups 212 and 214 of Figure 2. Location server 302 may be LMF 120, SUPL SLP 119, server 121, or server 123 shown in Figure 1, or LMF1 120a or SUPL SLP1 119a shown in Figure 2.

[0064] As shown in FIG. 3, at 310, the UE 105A receives a first sidelink positioning message from the UE 105B. The first sidelink positioning message may be, for example, an SLPP message as described above, or any of the message types described above. The first sidelink positioning message may be sent based on SL multicasting (also called SL groupcasting) or SL unicasting, for example, if the group includes three or more UEs, as shown in FIG. 3. In SL multicasting (also called SL groupcasting), a sidelink positioning message (e.g., an SLPP message) may be transmitted that includes a group destination address (e.g., that may be partially or completely included in a Layer 1 protocol header and / or a Layer 2 protocol header in the sidelink positioning message). A receiving UE (e.g., the UE 105A) belonging to the group with this group destination address then recognizes the group destination address in the sidelink positioning message and receives, decodes, and processes the sidelink positioning message. In SL unicast, the sidelink positioning message may be sent including a UE destination address (e.g., a Layer 2 address assigned to UE 105A) and will only be received, decoded, and processed by the UE (e.g., UE 105A) whose destination address is included.

[0065] At 320, the UE 105A sends a first LPP / SLPP message (e.g., a first SLPP message or a first SLPP message embedded in an LPP message, as described above) to the location server 302, where the first SLPP message is based on or comprises the first sidelink positioning message.

[0066] At 330, UE 105A receives a second LPP / SLPP message from location server 302 in response to the first LPP / SLPP message from 320. The second LPP / SLPP message may be a second SLPP message or a second SLPP message embedded in an LPP message, as described above, and may be any of the message types described above. The second LPP / SLPP message (e.g., the second SLPP message) may include a location result for at least one UE in the group (e.g., UE 105A or UE 105B). For example, the location result for at least one UE in the group may include at least one of a range between the at least one UE and another UE, a direction from the at least one UE to another UE, a location of the at least one UE relative to a location of another UE, a velocity of the at least one UE, a relative velocity of the at least one UE relative to the velocity of another UE, or some combination thereof.

[0067] At 340, the UE 105A may send a second sidelink positioning message to one or more of the UEs 105B, 105C, and 105D in the group. The second sidelink positioning message may be an SLPP message and may be based on or include the second SLPP message received at 330. The second sidelink positioning message may be sent based on SL multicast, for example, as shown in FIG. 3, if the group includes three or more UEs.

[0068] The sidelink positioning messages in the signal flow 300 may be any of the message types described above. For example, the first sidelink positioning message at 310 and the first LPP / SLPP message at 320 may include sidelink positioning capabilities, sidelink positioning resources, or both for at least one UE in the group, e.g., UE 105B. The first LPP / SLPP message at 320 may include an LPP capability provision message and / or an SLPP capability provision message (e.g., if the SLPP capability provision message can be embedded in the LPP capability provision message). The second LPP / SLPP message at 330 and the second sidelink positioning message at 340 may include sidelink positioning capabilities, sidelink positioning resources, or both for UE 105A. The second LPP / SLPP message at 330 may include an LPP capability provision message and / or an SLPP capability provision message.

[0069] In another example, the first sidelink positioning message at 310 and the first LPP / SLPP message at 320 may include SL positioning reference signal (PRS) configuration for at least one UE in the group, e.g., UE 105A and / or UE 105B. The first LPP / SLPP message at 320 may include an LPP Request Assistance Data message, an LPP Provide Assistance Data message, an SLPP Request Assistance Data message, and / or an SLPP Provide Assistance Data message (e.g., where SLPP messages may be embedded in the same type of LPP message). The second LPP / SLPP message at 330 and the second sidelink positioning message at 340 may include SL positioning reference signal (PRS) configuration for at least one UE in the group, e.g., UE 105A or UE 105B. The second LPP / SLPP message at 330 may include an LPP Provide Assistance Data message and / or an SLPP Provide Assistance Data message (eg, where an SLPP Provide Assistance Data message may be embedded in an LPP Provide Assistance Data message).

[0070] In another example, the first sidelink positioning message at 310 and the first LPP / SLPP message at 320 may include sidelink positioning measurements obtained by at least one UE in the group, e.g., UE 105B. The first LPP / SLPP message at 320 may include an LPP Provide Location Information message and / or an SLPP Provide Location Information message (e.g., where the SLPP Provide Location Information message may be embedded in the LPP Provide Location Information message). The second LPP / SLPP message at 330 may include location results for at least one UE in the group, and the second LPP / SLPP message may include an LPP Provide Location Information message and / or an SLPP Provide Location Information message (e.g., where the SLPP Provide Location Information message may be embedded in the LPP Provide Location Information message).

[0071] The location server 302 may be, for example, an LMF or a SUPL SLP. If the location server 302 is a SUPL SLP, the first LPP / SLPP message is sent by the UE 105A to the location server 302 as part of a first SUPL message at 320, and the second LPP / SLPP message is received by the UE 105A from the location server 302 as part of a second SUPL message at 330. The first SUPL message and the second SUPL message may each include a SUPL POS message.

[0072] 4A is a block diagram 400A illustrating, by way of example, one implementation of the structure of an SLPP message 410. As shown, the SLPP message 410 includes a header 412 that may include a session ID, a transaction ID, a sequence number (seq no), an acknowledgment (or acknowledgement) sequence number, etc. The SLPP message 410 allows for one or more positioning methods or positioning method types. For example, the SLPP message 410 includes entries for positioning method / type 1 414, positioning method / type 2 416, and positioning method / type M 418 (e.g., M may be equal to 3 or greater). A positioning method may, for example, use one or more specific signal types (e.g., SL NR PRS, SL LTE PRS, Wi-Fi, GPS L1-L5, or any combination thereof) and support one method of determining location for the specific signal types (e.g., one of RTT, AOA, RSRP, or TDOA). On the other hand, a positioning method type uses one or more specific signal types and supports multiple positioning methods for the one or more signal types. For example, a positioning method type may use SL PRS signals (e.g., either SL NR PRS signals or both SL NR PRS signals and SL LTE PRS signals) and support multiple positioning methods using these SL PRS signals (e.g., support all of RTT, AOA, RSRP, and TDOA). Another positioning method type may use GNSS signals and support multiple positioning methods using GNSS signals (e.g., support GNSS code phase-based positioning and GNSS carrier phase-based positioning such as RTK).

[0073] The SLPP message 410 may be configured to support a positioning method or positioning method type (also referred to as a positioning type), or both a positioning method and a positioning method type. As shown, each positioning method / type 414, 416, and 418 in the SLPP message 410 may include parameters for each UE in the group, shown as identified by a member ID, e.g., UE1, UE2, ...UEn. It is possible that not all UEs in a group support the same positioning method / type, which may mean that parameters for UEs that do not support positioning method / type 414, 416, or 418 may not be present for that positioning method / type in the SLPP message 410. Support for multiple positioning methods or positioning method types in the SLPP message 410 may be advantageous when UEs do not all support the same positioning method or the same positioning method type, for example, some UEs may support positioning using RTK and SL PRS, while some other UEs support only RTK. However, in some implementations, the SLPP message 410 may provide support for only one positioning method (e.g., NR SL PRS RTT) or one positioning method type (e.g., NR SL PRS).

[0074] Figure 4B is a block diagram 400B illustrating another implementation of the structure of an SLPP message 420. Similar to block diagram 400A of Figure 4A, SLPP message 420 includes a header 422 that may contain information similar to header 412 in Figure 4A. However, here the data may be structured so that each UE in a group of n UEs has separate message sections 424, 426, and 428 in SLPP message 420, each containing that UE's parameters for each positioning method / type 1 through M supported by that UE.

[0075] FIG. 5 is a signal flow diagram illustrating four UEs (UEs A, B, C, and D) involved in an SLPP positioning session 500 without support from a location server such as an LMF. As with other figures provided herein, FIG. 5 is provided as a non-limiting example, and other embodiments may add, omit, and / or rearrange some of the illustrated operations. Here, a device and service discovery process may occur as shown in block 505, in which the UEs may discover each other and / or each UE may determine whether it has network service. In some embodiments, the device and service discovery process (of any of FIGS. 5-10) may be followed by potential SLPP session establishment (not shown).

[0076] After the device and service discovery process, a sidelink positioning and ranging function (SPRF) process 507 may begin in which the initiating UE (UE B in the example of FIG. 5, which may function as a coordinating UE) may broadcast or multicast an SLPP Capability Request message, as indicated by arrow 510, to request UE positioning capabilities from UEs A, C, and D. As used in the figures herein, a double-sided arrow, such as arrow 510, may indicate a transmission to multiple receiving devices (e.g., from one UE to all other UEs), including a broadcast or multicast transmission. However, it should be noted that alternative embodiments may similarly transmit a message to each of multiple receiving devices using a unicast transmission (e.g., a separate unicast transmission for each receiving device). It should be noted that UE B may be referred to as the "initiating UE," "coordinating UE," "anchor UE," "target UE," or "server UE."

[0077] The addressed UEs may then respond by each multicasting (or possibly broadcasting or unicasting) an SLPP Provide Capability message containing their UE positioning capabilities, as indicated by arrow 515. Each UE's UE positioning capabilities may include details of the UE's supported SL-PRS configurations and supported SL-PRS measurements. Taking the received UE capabilities into account, UE B may then (in this example) determine the SL-PRS configurations that may be broadcast and measured by all UEs and multicast an SLPP Provide Assistance Data message, as indicated by arrow 520, to deliver the determined SL-PRS configurations to the UEs participating in this session. Following this, UE B may send an SLPP Provide Location Information message, as indicated by arrow 525, to request specific SL-PRS measurement(s) from UEs A, C, and D. Each of the participating UEs (including the initiating UE B in FIG. 5) may then broadcast an SL-PRS according to its own SL-PRS configuration (e.g., at a different time than the SL-PRS transmitted by the other UEs) and perform the requested measurements of the SL-PRS broadcast by the other participating UEs, as shown in block 530. For example, in block 530a, UE A may transmit an SL-PRS according to its SL-PRS configuration and measure the SL-PRS transmitted by UEs B, C, and D, transmitted in blocks 530b, 530c, and 530d, respectively. (The other UEs have similar functionality in block 530.)

[0078] Once measurements are complete, all UEs (except initiator UE B) may then each multicast (or possibly broadcast or unicast) an SLPP Provide Location Information message, as indicated by arrow 535, which initiator UE B uses to determine the range and / or position of the group of UEs, as indicated by block 540. For example, the position / range calculation in block 540 may include obtaining location results (e.g., relative locations, direction, and / or range) for UEs A, B, C, and D. In some instances, initiator UE B may optionally distribute the obtained UE range / location to other UEs in the group, as indicated by dashed arrow 545. (As used herein, dashed arrows may represent optional functionality.) The transmission of a final SLPP Provide Location Information message by UE B may not be requested by the other UEs but may still be permissible according to applicable transaction rules for SLPP.

[0079] The procedure of FIG. 5 may be referred to as centralized UE location or “UE-assisted” UE location because one UE (UE B) may obtain location or location information for other UEs and then transmit this to the other UEs.

[0080] Figure 6 is a signal flow diagram illustrating another exemplary SLPP positioning session 600. As with the SLPP positioning session 500 of Figure 5, UE B is the initiator, and many of the initial actions are the same. However, in Figure 6, each UE in the group, including initiating UE B, may distribute its SL-PRS measurements to all other UEs in the group (e.g., via multicast) using an SLPP Provide Location Information message at arrow 610. This may enable each UE in the group to perform range or position calculations, as indicated at block 620. Each UE may then optionally transmit the range or position calculations it determined at block 620 to the other UEs in the group, as indicated at arrow 630.

[0081] The procedure of Figure 6 may be referred to as distributed or decentralized UE location or "UE-based" UE location because each UE may obtain location and location information for both itself and other UEs and then transmit this to other UEs.

[0082] According to some embodiments, two or more UEs may use SLPP with location server support to support ranging and positioning in a network-assisted mode. For example, this may be possible when at least one UE is in network coverage and is enabled to access a PLMN via a subscription. In this mode, UEs with PLMN access may be assisted by a location server (e.g., LMF) to use SLPP or may be requested by a location server to employ SLPP to obtain a mobile terminal location request (MT-LR) location result. In some instances of this network-assisted mode, for example, when some UEs are out of coverage, not all UEs may have PLMN access and be supported or provide support for it by the location server. Thus, location server support may be limited to only some UEs within a group of UEs participating in an SLPP positioning session. Figures 7-10, described in more detail below, illustrate how positioning in such a network-assisted mode may be performed.

[0083] FIG. 7 shows an exemplary SLPP positioning session 700 in which a location server (LS) (e.g., LMF) serves as an adjunct to initiating UE B to assist UE B in performing sidelink positioning. Similar to the processes of FIGS. 5 and 6 , there may be a device and service discovery process, as indicated by block 705, followed by an SPRF 710. The SPRF 710 may begin with the initiating UE (UE B) multicasting (or broadcasting) an SLPP Capability Request message, as indicated by arrow 715, to request sidelink positioning capabilities from the other participating UEs, which each respond with an SLPP Capability Provide message, as indicated by arrow 720. Initiating UE B may then request SL-PRS configuration information from the LS via an Assistance Data Request, as indicated by arrow 725, and the LS may respond with an SLPP Provide Assistance Data message, as indicated by arrow 735, which may include SL-PRS configuration for all UEs. In some embodiments, to enable the LS to determine appropriate SL-PRS configurations for all UEs, UE B may also provide the LS with the obtained SL-PRS capabilities of all UEs in the group in an SLPP Capability Provision message, indicated by optional arrow 730. (As shown in FIG. 7, this message may precede the SLPP Assistance Data Request message of arrow 725.)

[0084] The SLPP positioning session 700 may then proceed in a manner similar to the SLPP positioning method 500 of FIG. 5 to deliver assistance data, perform SL-PRS measurements, and deliver location information. In particular, UE B may transmit the SL-PRS configuration received from the LS to another UE in the group in an SLPP Provide Assistance Data message, indicated by arrow 740, followed by an SLPP Request Location Information message, indicated by arrow 745. The transmission of the SL-PRS measurements and measurements at block 750 and the transmission of the measurement results in an SLPP Provide Location Information message at arrow 755 may be similar to the corresponding operations in FIG. 5 above. As indicated by dashed block 760, UE B may perform range / location calculations using the measurements received from the other UEs. Alternatively, UE B may provide location measurements obtained from all UEs in the group to the LS in an SLPP Provide Location Information message, indicated by arrow 765, for range / location calculations performed in the LS, indicated by block 770. In instances where the LS performs the range / location calculation, the LS may then return the calculated range / location to the initiating UE B in an SLPP Provide Location Information message, as indicated by arrow 775. The UE B initiated SLPP transaction towards the LS may be part of a location session between UE B and the LS (e.g., mimicked by a Mobile Originated Location Request (MO-LR) or new supplementary service operation).

[0085] FIG. 8 illustrates another exemplary SLPP positioning session 800 in network-assisted mode. In this example, the LS initiates a sidelink positioning operation with a coordinating UE (UE B) to obtain a Mobile Terminated Location Request (MT-LR) location result. In this example, the coordinating UE (UE B) is the UE that coordinates obtaining SL-PRS configurations and reporting measurement results for a group of UEs participating in the SLPP positioning session 800. The LS may request the location of the coordinating UE and / or any UE (or all UEs) in the group. In some embodiments, the MT-LR that triggers the request from the location server to the coordinating UE may be triggered by an external client or application function (AF) (e.g., external client 130 in FIG. 1 ), which may provide all the necessary information for the MT-LR to the LS (e.g., to the LMF via GMLC and AMF). The LS may first request sidelink positioning capabilities for UE B, or possibly for another UE (e.g., UE A, C, D), from UE B via an SLPP Capability Request message, indicated by arrow 805, to which the adjusting UE may respond with an SLPP Capability Provide message, indicated by arrow 810. The LS may then request location results from UE B using a Supplementary Service Action Request, indicated by arrow 815. According to some embodiments, the supplementary service action request may indicate, for example, the type of location result requested (e.g., the location of one or more of the adjusting UE and / or other UEs), the identities and / or addresses of specific other UEs involved (e.g., UE A, C, D), or whether any UEs can be used, whether a single set of location results is requested (immediate location) or whether deferred (e.g., periodic or triggered) location results are requested, or any combination thereof. The supplementary service request may also include an embedded SLPP Location Information Request message indicating specific SLPP location results or measurements provided by the adjusting UE, and / or an embedded SLPP Provide Assistance Data message (e.g., SL-PRS configuration) for providing the adjusting UE with assistance data for SLPP positioning.

[0086] According to some embodiments, the reason for using a supplementary service request (at arrow 815) may be to allow for the inclusion of information such as UE address and identity information and the use of immediate versus deferred location, which may not be suitable for inclusion in an SLPP message. However, according to some embodiments, it is possible that an SLPP message (e.g., an SLPP Location Information Request) may be used instead. The target UE may then confirm or acknowledge the supplementary service request with a supplementary service response, indicated by arrow 820, which may indicate whether any requested UEs are available (e.g., whether UEs A, C, and D have been discovered by target UE B). The adjusting UE may then perform SLPP positioning using the operations of process 825 to obtain measurements and location results without the assistance of a further LS. As can be seen, the operations of process 825 mirror the operations in SLPP positioning session 500 of FIG. 5, as described above. Alternatively, the adjusting UE may initiate a process that echoes the operations in SLPP positioning session 600 of FIG. 6, as described above. At the end of process 825, the adjusting UE may optionally perform a position calculation (shown in block 830), in which case the adjusting UE may then provide the calculation results in an SLPP Provide Location Information message, shown at arrow 835. Otherwise, the adjusting UE may return measurements to the LS in an SLPP Provide Location Information message at arrow 835, in which case the LS may then determine the location (or range and / or bearing) for the adjusting UE and / or other UEs, as shown in block 840. In either case, the LS may then provide the location determination to an external client or AF (not shown). For deferred (periodic or triggered) location, SLPP positioning by the adjusting UE and returning location results to the LS may be repeated.

[0087] Figure 9 illustrates an SLPP positioning session 900 similar to that of Figure 8. However, in Figure 9, the LS actively assists SLPP positioning of four UEs, as in Figure 7. That is, the SLPP positioning session 900 of Figure 9 may proceed in a manner similar to that of the session of Figure 8, as previously described. However, in Figure 9, process 905 may include operations indicated by arrows 910, 915, and 920, which may be similar to the operations indicated by arrows 725, 730, and 735 of Figure 7, as previously described. The position calculation at block 925, the SLPP providing location information at arrow 930, and / or the position calculation at block 935 may be implemented in a manner similar to the corresponding steps of Figure 8, as previously described.

[0088] In some embodiments, the LS may indicate to the coordinating UE whether the LS should be used for such active assistance. For example, according to some embodiments, the LS indicates in the supplementary service request (arrow 940) whether assistance of the LS is not preferred, as in FIG. 8, or whether assistance is preferred (or required), as in FIG. 9.

[0089] It should be noted that while the procedures illustrated in Figures 5-10 are described herein as SLPP positioning "sessions," embodiments are not so limited. In alternative embodiments, the procedures illustrated in Figures 5-10 may not necessarily occur within an SLPP positioning session (e.g., using an established session ID, etc.). In some embodiments, some operations of the procedures (e.g., communications between the initiating / adjusting UE and the LS) may occur outside of an SLPP positioning session, while other operations may occur within the SLPP positioning session (e.g., communications between UEs, such as operations within an SPRF).

[0090] Depending on the desired functionality, embodiments may utilize SL positioning in conjunction with Uu positioning (eg, in conjunction with one or more base stations) to provide hybrid Uu and SL positioning.

[0091] The system architecture described above (e.g., with respect to Figures 1-9) may support interactions between UEs (e.g., between UE-A and UE-C, between UE-A and UE-B, or between UE-C and UE-D) and between UEs and 5G LTE. For interactions between UEs, SL signaling and messages for SL positioning and ranging may be carried over sidelink reference points between pairs of UEs, commonly referred to as PC5 reference points, and then using user plane transport, referred to as PC5-U reference points. Due to different deployment scenarios and operations, PC5 reference points may utilize different types of access technologies, including LTE-based PC5 and NR-based PC5 for V2X use, and 5G Proximity-Based Services (ProSe)-based PC5. For example, between V2X-capable UEs, control signaling may be carried over LTE PC5 or NR PC5. The control signaling may manage the actual AS layer sidelink positioning and ranging signaling and measurements, including SL PRS transmissions and measurements. As another example, between 5G ProSe-enabled UEs, control signaling for SL positioning and ranging may be performed over the 5G ProSe PC5 reference point, which may manage the actual AS layer sidelink positioning and ranging signaling and measurements, including SL PRS transmissions and measurements.

[0092] Procedures for performing enhanced sidelink positioning and ranging for n UEs, labeled UE1, UE2, ...UEn, according to embodiments herein are provided below with reference to Figures 10-15 and 18. In each of these procedures, one or more of the following may be supported: (i) the LMF communicates only with one UE (UE1) of the n UEs and not with the other UEs of the n UEs; (ii) at least one location result is obtained for each of the n UEs; (iii) one UE (UE1) adjusts the sidelink positioning of the n UEs based on information received from the LMF (e.g., assistance data or a request (e.g., for location measurements or location results)); (iv) all n UEs are target UEs; and (v) positioning-related messages exchanged among the n UEs and between UE1 and the LMF may be SLPP messages unless otherwise specified.

[0093] Figure 10 shows an example of a first enhanced procedure 1000 for sidelink positioning / ranging for a group of n UEs, labeled 1 to n, where n >= 2 and without LMF assistance (also referred to as "UE-only operation"). In this example, the n UEs may all have network coverage, may have partial network coverage, or may all be out of coverage. The various steps shown in Figure 10 may be performed as follows:

[0094] Step 1: UEs 1-n may discover each other. Discovery may be network-assisted or not and may use the Device and Service Discovery Function (DSDF) service in each UE.

[0095] Step 2: A sidelink positioning / ranging session may be established between UEs 1-n.

[0096] Step 3: UEs 1-n may exchange sidelink positioning / ranging capabilities, for example using SLPP signaling.

[0097] Step 4: Sidelink reference signal transmission and measurement may be configured in UEs 1 to n, for example by one coordinating UE, or in a distributed manner.

[0098] Step 5: Sidelink reference signal transmission and measurement may be performed by each of UEs 1 to n according to the configuration in step 4.

[0099] Step 6: UEs 1-n may exchange the sidelink measurements obtained in step 5, for example using SLPP signaling.

[0100] Step 7: UEs 1-n can calculate a sidelink positioning / ranging location result from the sidelink measurements obtained in steps 5 and 6. The sidelink positioning / ranging location result may include absolute location and / or velocity, relative location and / or velocity, range, and / or direction for UEs 1-n. The calculation may be distributed across all UEs 1-n or centralized in one UE or a few UEs.

[0101] Step 8: UEs 1-n may exchange the sidelink positioning / ranging location results obtained in step 7, for example using SLPP signaling. Steps 5-8 or steps 4-8 may be repeated.

[0102] A second enhanced procedure for sidelink positioning / ranging can include an MO-LR procedure with LMF assistance. In this procedure, sidelink positioning / ranging of a group of two or more UEs that are in network coverage or partial network coverage can be triggered by the UE itself and assisted by the LMF using the 5GC-MO-LR procedure with some enhancements. The reason for reusing and enhancing the existing 5GC-MO-LR procedure is to reduce the new impact on the UE, 5GCN, LCS client, and AF.

[0103] Figure 11 shows an enhanced MO-LR procedure 1100 applied to n UEs, labeled 1 through n, where n >= 2. The procedure is invoked by one UE, assumed to be UE1 in Figure 11. According to this procedure, at least one of the UEs (UE1 in this example) is in network coverage, while the other UEs may or may not be in coverage. The various steps shown in Figure 11 may be performed as follows:

[0104] Step 1: UE1 may discover UE2 through n. Discovery may be network-assisted or not and may be supported by the DSDF within each UE.

[0105] Step 2: UE1 may acquire the sidelink positioning capabilities of UE2~n, for example, using SLPP.

[0106] Step 3: UE1 may send a supplementary service MO-LR request to its serving AMF. The MO-LR request may include a request for sidelink positioning / ranging and indicate the other UEs 2-n (e.g., by including their respective local labels or application-level addresses or IDs). The MO-LR request may indicate whether assistance data from the LMF is requested, whether location calculation assistance from the LMF is requested, and / or whether the sidelink positioning / ranging location result should be forwarded to the LCS client or AF. Details of the LCS client or AF (and possibly the GMLC) and global identification information for all UEs (e.g., application-level addresses or IDs or General Public Subscription Identifiers (GPSIs)) may also be included for forwarding to the LCS client or AF. In the case of location calculation assistance from the LMF, the preferred type of sidelink positioning / ranging location result (e.g., absolute location, relative location, relative velocity, or range / direction between the pair of UEs) may be included, and QoS may be included.

[0107] Step 4: The serving AMF may select an LMF (e.g., an LMF that supports sidelink positioning / ranging) and may send an Nlmf_Location_DetermineLocation service operation towards the LMF with information from the MO-LR request.

[0108] Step 5: The LMF can send a request for the capabilities of all UEs 1-n (e.g., an SLPP request) to UE 1. The request can be sent to UE 1 via the serving AMF using the signaling connection between UE 1 and the serving AMF used to send the MO-LR request in step 3.

[0109] Step 6: UE1 may return its capabilities and the capabilities of UE2-n obtained in step 2 to the LMF. This step may occur, for example, as part of step 3, if an SLPP message carrying the capabilities is embedded in the MO-LR request. The capabilities may include the SL RAT (e.g., NR, LTE) and SL frequencies supported by each of UE1-n for sidelink positioning / ranging.

[0110] Step 7: If UE1 indicates that assistance data is required in step 3, UE1 may send a request for specific assistance data to the LMF. The specific assistance data may include assistance data to enable measurements of SL PRS or other measurements (e.g., in the case of RTK) and / or assistance data to enable the UE (e.g., UE1) to calculate a location result from location measurements obtained by some or all of the n UEs. Similar to step 6, this step may occur as part of step 3, for example, if an SLPP message indicating the requested assistance data is embedded in the MO-LR request.

[0111] Step 8: If step 7 occurs, the LMF may return the requested specific assistance data to UE 1. The specific assistance data may assist UE 1-n in obtaining sidelink location measurements and / or may assist UE 1 in calculating sidelink positioning / ranging location results. The specific assistance data may be determined by the LMF based on the request for specific assistance data received from UE 1 in step 7 and / or based on the capabilities for UE 1-n received in step 6.

[0112] Step 9: If the MO-LR request in step 3 indicated that location calculation assistance is requested and / or indicated forwarding of sidelink positioning / ranging location results to an LCS client or AF, the LMF may send a request for location information to UE 1. The requested location information may include SL location measurements and / or SL location results for one or more of UEs 1-n.

[0113] Step 10: UE1 may trigger a sidelink positioning / ranging procedure between UEs 1-n, e.g., as in steps 2-6 of Figure 10. This step may be supported using any assistance data received in step 8. As part of this step, UEs 1-n obtain sidelink location measurements of sidelink signals transmitted by other UEs.

[0114] Step 11: If UE1 did not request location calculation assistance from the LMF in step 3, UE1 may calculate a sidelink positioning / ranging location result for itself and possibly for each of the other UEs 2-n based on the sidelink location measurements obtained in step 10, and possibly using any assistance data received in step 8. The sidelink positioning / ranging location result may include absolute location, relative location, velocity, direction, and / or range for one or more of UEs 1-n. Some or all of the location calculations may be performed by some or all of UEs 2-n, and the location result is then forwarded to UE1.

[0115] Step 12: If UE1 received a request for location information in step 9, UE1 may send a response to the LMF, including either the sidelink location measurements obtained in step 10 or, if step 11 occurred, the sidelink positioning / ranging location result obtained in step 11. Step 12 may also be performed when no request for location information was received in step 9, to indicate to the LMF that the sidelink positioning / ranging procedure between UE1-n is completed and that no further assistance from the LMF is required. In this case, step 12 may include little or no location information.

[0116] Step 13: If step 12 occurs and location computation assistance from the LMF was requested in step 3, the LMF may calculate sidelink positioning / ranging location results for UE1-n from the sidelink location measurements received in step 12. The sidelink positioning / ranging location results may include absolute locations, relative locations, velocities, directions or ranges for some or all of the UE1-n.

[0117] Step 14: The LMF may return an Nlmf_Location_DetermineLocation service operation response to the AMF, including any sidelink positioning / ranging location results received in step 12 or calculated in step 13.

[0118] Step 15: If sidelink positioning / ranging location results were received in step 14, the AMF may send the sidelink positioning / ranging location results to the GMLC, which may forward them to the AF or LCS client if this was requested in step 3. The sidelink positioning / ranging location results may include the global identities for UE2-n received in step 3 and the global identity of UE1. According to some embodiments, sending the location results and global identities for UE2-n to the AF or LCS client may require privacy verification for or from UE2-n and / or from the Home PLMMs (HPLMNs) of UE2-n (as well as privacy verification for UE1).

[0119] Step 16: The LMF may return a supplementary service MO-LR response to UE1, which may include any sidelink positioning / ranging location results calculated in step 13, if step 13 was performed. UE1 may then forward any sidelink positioning / ranging location results to UE2~n.

[0120] The messages in Figure 10 shown as being transferred between UE1-n may be SLPP messages. The messages in Figure 10 shown as being transferred between UE1 and the LMF may be supplementary service messages as this is stated, or may otherwise be either SLPP messages or LPP messages with an SLPP message(s) embedded within each LPP message. This same signaling convention may also be used in Figures 11-15 and 18, which are described next.

[0121] A third enhanced procedure for sidelink positioning / ranging can include an LMF-assisted MT-LR procedure, in which sidelink positioning / ranging location results for a group of two or more UEs that are in network coverage or partial network coverage can be requested by an LCS client or an AF and assisted by the LMF using the 5G-CDMA-MT-LR procedure with some enhancements. The reason for reusing and enhancing the existing MT-LR procedure is to reduce the new impact on the UE, 5G-CDMA, LCS client, and AF.

[0122] 12 shows an extended MT-LR procedure 1200 applied to n UEs 1-n, where n≧2. Typically, this may require the LCS client or AF to be aware that UEs 1-n are or may be close to each other. This may be possible in some IIoT scenarios (e.g., a factory or warehouse) or when the AF or LCS client has other information indicating this. At least one of the UEs (UE 1 in this example) must be in network coverage, while the other UEs may or may not be in coverage.

[0123] Step 1: The LCS client or AF can initiate the MT-LR procedure by sending a request to GMLC (which may be H-GMLC) or an NEF (not shown in FIG. 12) that can forward the request to GMLC. GMLC then forwards the request to the serving AMF for UE1, which then forwards the request to the LMF. The LCS client or AF can include global identities (e.g., GPSI and / or application layer ID) of n UEs 1-n in the request and can indicate one UE (assumed here to be UE1) as the primary target UE. If the LCS client or AF does not indicate a primary target UE that is in network coverage, the GMLC or serving AMF can select a primary target UE from among UE1-n. In some embodiments, the primary target UE should have network coverage, preferably a PLMN serving the LCS client or AF. The primary target UE later receives the MT-LR request and can coordinate sidelink positioning / ranging among other UEs. Thus, at the initiation of the MT-LR procedure, a location request may be sent by the GMLC to the serving AMF of the primary target UE. The MT-LR location request may include the type of sidelink positioning / ranging location result requested (e.g., absolute location, relative location, velocity, range, and / or direction), QoS, and may include a condition for canceling the location request when all UEs 1-n cannot be found for positioning. The conditions for canceling the location request may include (i) one or more specific identified UEs cannot be found, and / or (ii) the total number of found UEs 1-n is less than a quorum q, where 1≦q≦n.

[0124] According to some embodiments, privacy verification may be performed for all n UEs 1-n. If all n UEs have the same HPLMN, this may be performed by the GMLC, here H-GMLC, at the initiation of the MT-LR procedure. If all n UEs are in network coverage and have the same serving AMF, privacy notification / verification (if required) for each of UEs 1-n may be performed by a common serving AMF. If some of UEs 1-n have different HPLMNs, are not in network coverage, or have different serving AMFs, some additional support may be used.

[0125] Step 2: The LMF may send a supplementary service MT-LR request to the primary target UE 1, which may include the global identities of the other UEs 2-n, the conditions for canceling the location request if all UEs 1-n cannot be discovered, and the type of sidelink positioning / ranging location result requested.

[0126] Step 3: UE1 may attempt to discover other UE2-n if they have not yet been discovered. If not all UE2-n have been discovered and if the conditions for canceling the location request when not all UE1-n can be discovered (e.g., the conditions described above for step 1) are met, UE1 may return a negative response in step 5, and the procedure may end after the LMF returns a negative response to the LCS client or AF via the AMF and GMLC.

[0127] Step 4: UE1 may acquire (eg, request and receive) the sidelink positioning capabilities of UE2-n, if not already acquired.

[0128] Step 5: UE1 may return a supplementary service MT-LR response to the LMF indicating whether the MT-LR request can be supported and which of UE2-n have been discovered and are available for positioning.

[0129] Step 6: Sidelink positioning / ranging for UE1-n may occur for MO-LR as described for steps 7-13 of Figure 11, except that the sidelink positioning / ranging location result may always be obtained and in step 8 or step 9 of Figure 11 the LMF may indicate to UE1 whether the sidelink positioning / ranging location result is calculated by the LMF or by UE1 (and / or by other UEs).

[0130] Step 7: The LMF may return the sidelink positioning / ranging location results for UE1-n to the LCS client or AF via the serving AMF and GMLC.

[0131] A fourth enhanced procedure for sidelink positioning / ranging may include a periodic or triggered MT-LR procedure with LMF assistance. In this procedure, sidelink positioning / ranging results for a group of two or more UEs that are in network coverage or partial network coverage may be requested periodically or when some trigger event occurs by the LCS client or AF, and may be assisted by the LMF using a periodic or triggered 5G-CDMA-MT-LR procedure with some enhancements. The reason for reusing and enhancing the existing periodic or triggered MT-LR procedure may be to reduce the new impact on the UEs, 5G-CDMA-MT-LR procedure, the LCS client, and the AF.

[0132] 13 shows an extended periodic or triggered MT-LR procedure 1300 applied to n UEs 1-n, where n≧2. Typically, this may require the LCS client or AF to be aware that UEs 1-n are, or may be, in close proximity to one another for the entire duration of the location report. This may be possible in some IIoT scenarios (e.g., a factory or warehouse) or, for example, when the AF or LCS client has other information indicating this. At least one UE (UE 1 in this example) must be in network coverage, while the other UEs may or may not be in coverage.

[0133] Phase 1: The LCS client or AF may initiate a periodic or triggered MT-LR procedure by sending a request to GMLC (which may be H-GMLC) or to an NEF (not shown in Figure 13) which may forward the request to GMLC, which then forwards the request to the serving AMF for UE1, which then forwards the request to the LMF. The LCS client or AF may include additional information in the location request as described for phase 1 in Figure 12. The primary target UE (here UE1) may also be selected as described for phase 1 in Figure 12. For triggered location reporting, different trigger events may be supported. Some examples of different trigger events are as follows: (i) an area event trigger where any one UE (or all UEs) enters, remains within, or leaves an area; (ii) an area event trigger where a single combined position for all n UEs 1-n (e.g., an average position which may be the centroid or "center of gravity" of the n distinct positions of the n UEs) enters, remains within, or leaves an area; (iii) a motion event trigger where any one UE (or all UEs) moves more than a threshold distance from its previous position; (iv) a motion event trigger where a single combined position for all n UEs 1-n (e.g., an average position which may be the centroid or "center of gravity" of the n distinct positions of the n UEs) moves more than a threshold distance; and (v) a range trigger where a particular type of range exceeds a threshold, falls below a threshold, and / or increases or decreases by more than a threshold amount. The particular type of range in (v) can be the maximum range of all ranges between all pairs of UE1 to n, the minimum range of all ranges between all pairs of UE1 to n, the minimum range between any UE and each of the other n-1 UEs (there are n minimum ranges corresponding to n UEs, and a trigger occurs when any of the n minimum ranges exceeds a threshold), the average range between all pairs of UEs, or the maximum range between any UE and each of the other n-1 UEs (there are n maximum ranges corresponding to n UEs, and a trigger occurs when any of the n maximum ranges exceeds a threshold).

[0134] Note that privacy verification may be supported in procedure 1300 in the manner described above with respect to procedure 1200 of FIG.

[0135] Step 2: The LMF may trigger MT-LR sidelink positioning / ranging for UE1-n, as in steps 2-6 of Fig. 12. When all UE1-n have not been discovered (in this case, the location request is canceled by the LMF), the LMF may verify whether the conditions for canceling the location request are met and may obtain the capabilities of UE1-n, but may not necessarily obtain immediate sidelink positioning / ranging location results.

[0136] Step 3: The LMF can send a supplementary service LCS periodic-triggered call request to UE1, including the event trigger(s) provided in step 1, the global IDs of UE2-n, and indicating sidelink positioning / ranging for UE1-n.

[0137] Stage 4: UE1 can establish periodic or triggered sidelink positioning sessions with UE2-n, which allows UE2-n to participate in detecting trigger events in stage 7 (e.g., events affecting some or all of UE2-n) and can speed up sidelink positioning / ranging in stage 8 by pre-configuring UE2-n.

[0138] Step 5: UE1 can return an LCS periodic-triggered page response to the LMF indicating which of UE2-n can support periodic or triggered sidelink positioning / ranging.

[0139] Step 6: The LMF may send a confirmation to the LCS client or AF via GMLC only or via the serving AMF and GMLC whether periodic or triggered sidelink positioning / ranging has been successfully activated in UE1 (and UE2-n).

[0140] Step 7: UE1 may wait for an event to be detected (e.g., by UE1 or by one of the other UEs 2-n), obtain sidelink positioning / ranging measurements, possibly calculate a sidelink positioning / ranging location result, and then send a supplementary service event report to the LMF and receive an event report acknowledgment back from the LMF. Note that the detection of the event by UE1 may depend on detecting the event related to one or more of UEs 1-n, and any sidelink positioning / ranging measurements and calculation of the location result may require interaction between UEs 1-n (e.g., using SLPP).

[0141] Step 8: If sidelink positioning / ranging location results for UE1-n are requested and were not provided to the LMF as part of step 7, the LMF may perform sidelink positioning / ranging for UE1-n, e.g., steps 5-13 of FIG. 11 .

[0142] Step 9: The LMF may send an event report (e.g., via the GMLC) to the LCS client or the AF, which may include any sidelink positioning / ranging location results obtained in step 7 or step 8. If sidelink positioning / ranging location results are provided by the LMF for only some of the UEs 1-n (e.g., in several consecutive event reports), the GMLC or LCS client or the AF may cancel the periodic or triggered sidelink positioning / ranging.

[0143] Step 10: Steps 7-9 may be repeated until the periodic or triggered sidelink positioning / ranging is canceled or until the maximum duration or maximum number of event reports is reached.

[0144] A fifth enhanced procedure for sidelink positioning / ranging may include a SL-MO-LR procedure for ranging between target UEs with LMF assistance. This procedure may enable a UE to request assistance from an LMF to obtain sidelink positioning / ranging location information for itself and one or more other target UEs. The procedure may be similar to the MO-LR procedure shown in Figure 11, but with some differences and additional details.

[0145] 14 illustrates a SL-MO-LR procedure 1400 that enables a UE, designated UE1, with the assistance of an LMF in the serving PLMN for UE1, to obtain sidelink positioning / ranging location results for UE1 and one or more other UEs, designated UE2, UE3, ...UEn. The sidelink positioning / ranging location results may include absolute location, relative location, velocity or range, and direction between the pair of UEs. According to the present disclosure, embodiments may utilize any combination of the operations described in steps 1-21 of FIG. 14 described below.

[0146] As a prerequisite for the fifth enhancement procedure of Figure 14, UE1 may be in-coverage and registered with a serving PLMN. UEs 2-n may or may not be in-coverage, and if in-coverage, may or may not be registered with the same serving PLMN as UE1.

[0147] Phase 1: Procedures and signaling specified for ProSe or V2X may be used (e.g., by the PCF or serving AMF) to provision ranging / SL positioning service authorization and policy / parameter provisioning to one or more of UE1 and UE2-n.

[0148] Step 2: UE1 may discover UE2-n. In some embodiments, discovery may use direct discovery. UE1 may also receive (from UE2-n) an application layer ID and / or a global ID (e.g., GPSI) for UE2-n when discovering UE2-n.

[0149] Step 3: Secure groupcast and / or unicast links may be established between UEs 1-n to enable UE 1 to exchange sidelink positioning messages with each of UEs 2-n via PC5-U, and possibly UEs 2-n to exchange sidelink positioning messages between each other via PC5-U.

[0150] Step 4: UE1 may notify UE2-n of its intention to perform ranging / SL positioning of UE2-n using the groupcast and / or unicast links established in step 3. Each of UE2-n verifies that ranging / SL positioning may be allowed according to any service authorization and policy / parameter provisioning received in step 1, including whether ranging / SL positioning results may be forwarded to the LCS client or, if used, to the AF. Quality of Service (QoS) requirements for ranging / SL positioning may also be agreed upon.

[0151] Step 5: UE1 can acquire sidelink positioning capabilities of UE2~n using the groupcast and / or unicast links established in step 3.

[0152] Step 6: Based on the sidelink positioning capability of UE1, the sidelink positioning capabilities of UE2-n received in step 5, the QoS requirements agreed upon in step 4, the ranging / SL positioning service permissions and policies / parameters received in step 1, and whether the location results should be forwarded to the LCS client or the AF, UE1 can determine whether assistance for sidelink positioning / ranging of UE1-n should be obtained from the LMF. If yes, steps 7-21 can be executed. If not, UE1 can only execute steps 15 and 16 without LMF assistance.

[0153] Step 7: When UE1 is in CM-IDLE state, UE1 may trigger a UE triggered service request to establish a signaling connection with UE1's serving AMF.

[0154] Step 8: UE1 may send a supplementary service SL-MO-LR request to its serving AMF in a UL NAS transport message. The SL-MO-LR request may indicate the other UEs 2-n (using local or global identities), any requested assistance data, whether location calculation assistance from the LMF is requested, and whether the location results should be forwarded to the LCS client or the AF. For forwarding to the LCS client or the AF, details (e.g., addresses) of the LCS client or the AF (and possibly the GMLC) and global identities of all UEs may also be included. For location calculation assistance from the LMF, the preferred type of sidelink positioning / ranging location result (e.g., absolute location, relative location, velocity, or range and direction between the pair of UEs) may be included, along with QoS.

[0155] Step 9: The serving AMF may select an LMF (e.g., an LMF that supports sidelink positioning / ranging) and send an Nlmf_Location_DetermineLocation service operation towards the LMF with information from the SL-MO-LR request.

[0156] Step 10: The LMF can send a request to UE1 for the capabilities of all UE1~n.

[0157] Step 11: UE1 may return its capabilities and the capabilities of UE2-n obtained in step 5 to the LMF.

[0158] Step 12: If UE1 indicates in step 8 that assistance data is required, UE1 may send a request for specific assistance data to the LMF. The specific assistance data may include assistance data to enable measurements of SL PRS or other measurements (e.g., in the case of RTK) and / or may include assistance data to enable a UE (e.g., UE1) to calculate a location result from location measurements obtained by some or all of the n UEs.

[0159] According to some embodiments, steps 10 and 11 may be included as part of step 8 if UE1 includes a message containing UE1-n capabilities in the SL-MO-LR request in step 8. Step 12 may be included as part of step 8 if UE1 includes a message containing a request for specific assistance data in the SL-MO-LR request in step 8.

[0160] Step 13: If step 12 occurs, the LMF may return the requested specific assistance data to UE 1. The specific assistance data may assist UE 1-n in obtaining sidelink location measurements in step 15 and / or assist UE 1 in calculating sidelink positioning / ranging location results in step 16.

[0161] Step 14: If the MO-LR request in step 8 indicated that location calculation assistance is requested and / or indicated forwarding of sidelink positioning / ranging location results to the LCS client or AF, the LMF may send a request for location information to UE1.

[0162] Step 15: UE 1 may trigger a sidelink positioning / ranging procedure between UEs 1-n, in which UEs 1-n obtain sidelink location measurements and UEs 2-n forward those sidelink location measurements to UE 1. For example, this may occur as described for steps 4-6 of FIG.

[0163] Step 16: If UE1 did not request location calculation assistance from the LMF in step 8, UE1 may calculate sidelink positioning / ranging location results for itself and each of UEs 2-n based on the sidelink location measurements obtained in step 15, and possibly using the assistance data received in step 13. The sidelink positioning / ranging location results may include absolute location, relative location, velocity, or range and direction between pairs of UEs 1-n. According to some embodiments, some or all of UEs 2-n may calculate location results as part of step 15 and forward these results to UE1 to assist in step 16.

[0164] Step 17: If UE1 received a request for location information in step 14, UE1 may send a response to the LMF, including either the sidelink location measurements obtained in step 15 or the sidelink positioning / ranging location result obtained in step 16 if step 16 was performed. Step 17 may also be performed when no request for location information was received in step 14, to indicate to the LMF that the sidelink positioning / ranging procedure between UE1-n is completed and that no further assistance from the LMF is required. In this case, little or no location information may be included by UE1 in step 17.

[0165] Step 18: If step 17 occurs and location calculation assistance from the LMF was requested in step 8, the LMF may calculate a sidelink positioning / ranging location result for UE1-n from the sidelink location measurements received in step 17. The sidelink positioning / ranging location result may include absolute location, relative location, velocity or range, and direction between the pair of UE1-n.

[0166] Step 19: The LMF may return an Nlmf_Location_DetermineLocation service operation response to the AMF, which may include any sidelink positioning / ranging location results received in step 17 or calculated in step 18.

[0167] Step 20: If a sidelink positioning / ranging location result was received in step 19, the AMF sends the sidelink positioning / ranging location result to the GMLC and may send it to the AF or LCS client if this was requested in step 8. The sidelink positioning / ranging location result may include the global identity for UE1-n received in step 8. According to some embodiments, sending the location result and the global identity for UE1-n to the AF or LCS client may involve privacy verification from UE1-n and / or from the HPLMN of UE1-n.

[0168] Step 21: The LMF may return a supplementary service SL-MO-LR response to UE1 in a DL NAS transport message, which may include any sidelink positioning / ranging location results calculated in step 18 if step 18 was performed. UE1 may then forward any sidelink positioning / ranging location results to UE2~n.

[0169] A sixth enhanced procedure for sidelink positioning / ranging may include a SL-MT-LR procedure for ranging between target UEs. This procedure may enable an LCS client or AF to request and obtain sidelink positioning / ranging location information for two or more target UEs.

[0170] FIG. 15 illustrates a SL-MT-LR procedure 1500 for enabling an LCS client or AF to obtain sidelink positioning / ranging location results for a group of n UEs (n≧2) UE1, UE2, ...UEn. The sidelink positioning / ranging location results may include absolute location, relative location, velocity, or range and direction between a pair of UEs. According to the present disclosure, embodiments may utilize any combination of the operations described in steps 1-20 of FIG. 15 described below.

[0171] According to some embodiments, as a prerequisite for the sixth extension procedure of FIG. 15, at least one of the n target UEs (here assumed to be UE1) is in coverage and can be registered with the serving PLMN.

[0172] Step 1: The LCS client or AF (via the Network Publication Function (NEF)) may send an LCS service request to the (H)GMLC for sidelink positioning / ranging location results for n target UEs, each of which may be identified by a GPSI and / or SUPI. The request may include the required QoS, the required location result (e.g., absolute location, relative location, speed or range and direction between the pair of UEs), and other attributes. The (H)GMLC or NEF may authorize the LCS client or AF for use of the LCS service. If the authorization fails, the remaining steps may be skipped, and the (H)GMLC or NEF responds to the LCS client or AF with a service authorization failure. In some cases, the (H)GMLC may derive the QoS from at least some of the GPSIs and / or SUPIs of the n target UEs, and possibly from other of the GPSIs and / or SUPIs provided by the LCS client or AF, or from subscription data in or accessible to the (H)GMLC, or from other data provided by the LCS client or AF.

[0173] A preferred ordering for the n target UEs may be indicated by the LCS client or AF to assist in determining a primary target UE in stage 3. The (H)GMLC may modify any preferred ordering provided by the LCS client or AF. For example, the (H)GMLC may prioritize UEs whose PLMN of the (H)GMLC is the UE's Home PLMN (HPLMN). In addition, an application layer ID for each of the n target UEs may be included to enable UE discovery in stage 12. The request may also include a condition for canceling the location request when all n target UEs cannot be discovered for positioning. The condition for canceling the location request may include (i) one or more specific target UEs cannot be discovered, and / or (ii) the total number of discovered target UEs is less than a quorum q, where 2≦q≦n.

[0174] The LCS client or AF may determine that all n target UEs are in proximity to one another and may obtain their application layer IDs and / or global IDs prior to stage 1. For example, one or more of the n target UEs may be in communication with the LCS client or AF (e.g., using an application protocol such as Hypertext Transfer Protocol (HTTP) or HTTP Secure (HTTPS)) and may provide the LCS client or AF with the application layer IDs and / or global IDs of all n target UEs and the approximate (coarse) relative or absolute location of each of the n target UEs, and / or may indicate whether the n target UEs have performed mutual discovery (e.g., if one target UE has discovered the other n−1 target UEs). This may allow the LCS client or AF to provide an LCS service request in stage 1 and know in advance that the n target UEs are in proximity to one another.

[0175] Step 2: (H)GMLC may invoke a Nudm_SDM_Get service operation towards the UDM of each of the n target UEs to obtain the privacy settings of the UEs identified by their GPSI or SUPI. The UDM may return the target UE privacy settings of the UE. (H)GMLC may check the UE LCS privacy profile. If any of the n target UEs are not allowed to be located, steps 3 to 19 may be skipped.

[0176] Step 3: The (H)GMLC invokes the Nudm_UECM_Get service operation towards the UDM for each of the n target UEs (which may be in different PLMNs if the UEs are roaming), one at a time, possibly in sequence according to the preferred ordering in step 1 (if included), and may include the GPSI or SUPI of each UE being queried in the service operation for that UE. If any target UE is in coverage and registered with the serving PLMN, the UDM may return the network address of the current serving AMF and also the address of a visited GMLC (V-GMLC) for roaming UEs. The (H)GMLC may stop the Nudm_UECM_Get service operation towards the UDM(s) as soon as the UDM returns either the serving PLMN and AMF information for one of the n target UEs, or the serving PLMN and AMF information for one of the n target UEs indicating that one of the target UEs is served by the (H)GMLC's PLMN. This one UE may be treated as the primary target UE, here referred to as UE 1. According to some embodiments, the UDM may be aware of the serving AMF address at the time of UE registration to the AMF and / or the serving V-GMLC address at the time of UE registration to the AMF.

[0177] Step 4: In the non-roaming case, this step may be skipped. In the roaming case, the (H)GMLC may receive the V-GMLC's address (along with the network address of the current serving AMF) from the UDM in step 3; otherwise, the (H)GMLC may select an available V-GMLC in the VPLMN serving the UE using the Network Repository Function (NRF) based on the VPLMN identity information included in the AMF address received in step 3. The (H)GMLC may then send a location request to the V-GMLC by invoking the Ngmlc_Location_ProvideLocation service operation towards the V-GMLC. If the (H)GMLC does not receive the V-GMLC's address, or if the V-GMLC address is the same as the (H)GMLC address, or if both PLMN operators agree, the (H)GMLC may send a location service request message to the serving AMF. In some cases, step 4 may be skipped. (H) The GMLC may also provide the LCS client type of the AF, or the LCS client type of the LCS client, if received in step 1, and other attributes to be sent to the AMF in step 5.

[0178] Step 5: In case of roaming, the V-GMLC may first authorize that location requests are allowed from this (H)GMLC, PLMN, or this country. Otherwise, it may return an error response. The (H)GMLC or V-GMLC may invoke the Namf_Location_ProvidePositioningInfo service operation towards the AMF to request sidelink positioning / ranging location results for n target UEs. The service operation may include SUPI of UE1, application layer IDs and client types of the n UEs, and may further include the required LCS QoS, the required location results (e.g., absolute location, relative location, velocity or range and direction between the pair of UEs), and other attributes received or determined in step 1. According to some embodiments, the location request forwarded in steps 4 and 5 may also carry the result of the privacy check in step 2 and an indication of privacy-related actions.

[0179] In step 6, if UE1 is in connection management (CM) idle state, the AMF initiates a network triggered service request procedure to establish a signaling connection with UE1.

[0180] If the signaling connection establishment fails, steps 7 to 17 may be skipped.

[0181] Step 7: If the indicator of the privacy check related action indicates that UE1 may be notified or may be notified with privacy verification, and if UE1 supports LCS notification (e.g., according to UE capability information provided by UE1 to the AMF), a notification call message indicating the identity of the LCS client, the type of location request, and whether privacy verification may be required may be sent by the serving AMF to UE1.

[0182] Step 8: If step 7 occurs, UE1 may notify its user of the location request and, if privacy verification is required, wait for the user to grant or withhold authorization. UE1 may then return a notification result to the AMF indicating whether authorization is granted or denied for the LCS request if privacy verification is required. If the user does not respond after a predetermined time period, the AMF may infer a "no response" condition. The AMF may return an error response in step 18, and in the case of roaming, the V-GMLC may forward to the (H)GMLC in step 19. If privacy verification is required and there is no response with an indication received from the (H)GMLC indicating that the UE1 user denies authorization or prohibits the location request, steps 9-17 are skipped. According to some embodiments, for example, if some or all of the other target UEs have the same serving AMF as UE1, notification or privacy checks may be performed (as in steps 7 and 8) by the AMF for some or all of the other target UEs 2-n. For other UEs that are out of network coverage or have a different serving PLMN or a different serving AMF to UE1, the AMF may send a notification paging message to each UE via UE1 (which may act as a relay), and UE1 may return (e.g., relay) the notification result from each UE to the AMF. Alternatively, privacy verification by UE1 may be possible on behalf of all UEs (e.g., if all n target UEs belong to a common organization).

[0183] Step 9: The serving AMF may select an LMF (e.g., an LMF that supports sidelink positioning / ranging) and send an Nlmf_Location_DetermineLocation service operation to the LMF with the information received in step 5.

[0184] Step 10: The LMF may send an SL-MT-LR request as a supplementary service message to the serving AMF using the Namf_Communication_N1N2MessageTransfer service operation and a correlation ID identifying the LMF or the location request (e.g., the correlation ID may have been assigned by the AMF and sent to the LMF in step 9). The SL-MT-LR request may include the application layer IDs of the other UEs 2-n, a condition for canceling the location request when all UEs 2-n cannot be found, and the type of sidelink positioning / ranging location result requested.

[0185] Step 11: The serving AMF may use a DL NAS transport message to forward the SL-MT-LR request and a routing ID equal to the correlation ID to UE1.

[0186] Step 12: UE1 may attempt to discover other UE2-n using their application layer IDs if they have not yet been discovered. If all UE2-n are not discovered and if the conditions for canceling the location request when all n target UEs cannot be discovered are met, UE1 may return a negative response in step 14, and the procedure may end after the LMF returns a negative response to the LCS client or AF via the AMF and GMLC(s).

[0187] Step 13: UE1 may acquire (e.g., request and receive) the sidelink positioning capability of the discovered target UE, if not already acquired.

[0188] Step 14: UE1 may return a supplementary service SL-MT-LR response to the serving AMF in a UL NAS transport message, including the routing ID received in step 11. The SL-MT-LR response may indicate whether the SL-MT-LR request can be supported and which of UE2-n have been discovered and are available for positioning.

[0189] Step 15: The serving AMF may forward the SL-MT-LR response to the LMF indicated by the routing ID received in step 14 and may include a correlation ID equal to the routing ID.

[0190] Step 16: Sidelink positioning / ranging of UE1 and other discovered target UEs may occur for SL-MO-LR as described for steps 10 to 18 of Figure 14, except that the sidelink positioning / ranging location result may always be obtained and the LMF indicates to UE1 in step 13 or step 14 of Figure 14 whether the sidelink positioning / ranging location result is calculated by the LMF (in step 18 of Figure 14) or by UE1 (in step 16 of Figure 14).

[0191] Steps 17-20: The LMF may return the sidelink positioning / ranging location result to the LCS client or AF via the serving AMF, V-GMLC (if included), (H)GLMC, and NEF in the case of AF.

[0192] 16 is a block diagram of one embodiment of a UE 1600 (e.g., a UE 105) that may be utilized as described above herein (e.g., in connection with the preceding figures regarding UEs, mobile devices, etc.). It should be noted that FIG. 16 is intended only to provide a generalized illustration of various components, any or all of which may be utilized as desired. Furthermore, the functionality of the UE described herein may be performed by one or more of the hardware and / or software components illustrated in FIG. 16.

[0193] 16. UE 1600 is shown comprising hardware elements that may be electrically coupled (or may communicate in other ways, as needed) via bus 1605. The hardware elements may include processor(s) 1610, which may include, but are not limited to, one or more general-purpose processors (e.g., application processors), one or more special-purpose processors (such as DSP chips, graphics acceleration processors, application-specific integrated circuits (ASICs)), and / or other processing structures or means. Processor(s) 1610 may include one or more processing units that may be housed in a single integrated circuit (IC) or multiple ICs. As shown in FIG. 16, some embodiments may have a separate DSP 1620 depending on desired functionality. Location determination and / or other decisions based on wireless communication may be performed in processor(s) 1610 and / or in wireless communication interface 1630 (described below). The UE 1600 may also include one or more input devices 1670, which may include, but are not limited to, one or more keyboards, touchscreens, touchpads, microphones, buttons, dials, switches, etc., and one or more output devices 1615, which may include, but are not limited to, one or more displays (e.g., touchscreens), light-emitting diodes (LEDs), speakers, etc.

[0194] The UE 1600 may also include a wireless communication interface 1630, which may comprise, but is not limited to, a modem, a network card, an infrared communication device, a wireless communication device, and / or a chipset (such as a Bluetooth device, an IEEE 802.11 device, an IEEE 802.15.4 device, a Wi-Fi device, a WiMAX device, a WAN device, and / or various cellular devices), which may enable the UE 1600 to communicate with other devices as described in the above embodiments. The wireless communication interface 1630 may enable data and signaling to be communicated with and / or measured (e.g., transmitted and received) by other UEs (e.g., using SL signaling), TRPs of the network, e.g., via an eNB, gNB, ng-eNB, access point, various base stations and / or other access node types, and / or other network components, computer systems, and / or any other electronic devices communicatively coupled to the TRPs, as described herein. Communication may be performed via one or more wireless communication antenna(s) 1632 that transmit and / or receive wireless signals 1634. According to some embodiments, the wireless communication antenna(s) 1632 may include multiple individual antennas, an antenna array, or any combination thereof. The antenna(s) 1632 may be capable of transmitting and receiving wireless signals using beams (e.g., Tx beams and Rx beams). Beamforming may be performed using digital and / or analog beamforming techniques using respective digital and / or analog circuitry. The wireless communication interface 1630 may include such circuitry.

[0195] Depending on desired functionality, the wireless communication interface 1630 may include separate receivers and transmitters, or any combination of transceivers, transmitters, and / or receivers, for communicating with other UEs, base stations (e.g., ng-eNBs and gNBs), and other terrestrial transceivers, such as wireless devices and access points. The UE 1600 may communicate with different data networks, which may comprise a variety of network types. For example, one such network type may include a wireless wide area network (WWAN), which may be a code division multiple access (CDMA) network, a time division multiple access (TDMA) network, a frequency division multiple access (FDMA) network, an orthogonal frequency division multiple access (OFDMA) network, a single-carrier frequency division multiple access (SC-FDMA) network, a WiMAX (IEEE 802.16) network, etc. A CDMA network may implement one or more radio access technologies (RATs), such as CDMA2000, wideband code division multiple access (WCDMA), etc. CDMA2000® includes the IS-95 standard, the IS-2000 standard, and / or the IS-856 standard. A TDMA network may implement Global System for Mobile Communications (GSM), Digital Advanced Mobile Phone System (D-AMPS), or some other RAT. An OFDMA network may employ Long Term Evolution (LTE), LTE Advanced, Fifth Generation (5G) New Radio (NR), etc. 5G NR, LTE, LTE Advanced, GSM, and WCDMA are described in documents from the 3rd Generation Partnership Project (3GPP). CDMA2000® is a standard developed by the "3rd Generation Partnership Project 2" (3GPP). rdand other related documents from an organization named 3GPP2 (3rd Generation Partnership Project 2). 3GPP and 3GPP2 documents are publicly available. A wireless local area network (WLAN) may also be an IEEE 802.11x network, and a wireless personal area network (WPAN) may be a Bluetooth network, an IEEE 802.15x network, or some other type of network. The techniques described herein may also be used for any combination of WWAN, WLAN, and / or WPAN.

[0196] The UE 1600 may further include sensor(s) 1640. The sensor(s) 1640 may include, but are not limited to, one or more inertial sensors and / or other sensors (e.g., accelerometer(s), gyroscope(s), camera(s), magnetometer(s), altimeter(s), microphone(s), proximity sensor(s), light sensor(s), barometer(s), etc.), some of which may be used to obtain location-related measurements and / or other information.

[0197] An embodiment of the UE 1600 may also include a Global Navigation Satellite System (GNSS) receiver 1680 capable of receiving signals 1684 from one or more GNSS satellites using an antenna 1682 (which may be the same as the antenna 1632). Positioning based on GNSS signal measurements may be utilized to complement and / or incorporate the techniques described herein. The GNSS receiver 1680 may use conventional techniques to extract a position of the UE 1600 from GNSS satellites of a GNSS system such as Global Positioning System (GPS), Galileo, GLONASS, the Quasi-Zenith Satellite System (QZSS) over Japan, the IRNSS over India, or the Beidou Navigation Satellite System (BDS) over China. Furthermore, the GNSS receiver 1680 can be used with various augmentation systems (e.g., Satellite Based Augmentation System (SBAS)) that may be associated with or otherwise capable of being used with one or more global and / or regional navigation satellite systems, such as, for example, the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Multi-functional Satellite Augmentation System (MSAS), and the Geo Augmented Navigation system (GAGAN).

[0198] It may be noted that while the GNSS receiver 1680 is shown in FIG. 16 as a separate component, embodiments are not so limited. As used herein, the term “GNSS receiver” may include hardware and / or software components configured to acquire GNSS measurements (measurements from GNSS satellites). In some embodiments, the GNSS receiver may therefore comprise a measurement engine executed (as software) by one or more processors, such as the processor(s) 1610, the DSP 1620, and / or a processor within the wireless communication interface 1630 (e.g., in a modem). The GNSS receiver may also optionally include a positioning engine, which can use the GNSS measurements from the measurement engine to determine the position of the GNSS receiver using an Extended Kalman Filter (EKF), Weighted Least Squares (WLS), a particle filter, or the like. The positioning engine may also be executed by one or more processors, such as the processor(s) 1610 or the DSP 1620.

[0199] The UE 1600 may further include and / or be in communication with memory 1660. The memory 1660 may include, but is not limited to, local and / or network-accessible storage devices, disk drives, drive arrays, optical storage devices, solid-state storage devices such as random access memory (RAM) and / or read-only memory (ROM), which may be programmable, flash-updateable, etc. Such storage devices may be configured to implement any suitable data store, including, but not limited to, various file systems, database structures, etc.

[0200] The memory 1660 of the UE 1600 may also comprise software elements (not shown in FIG. 16 ) including other code, such as an operating system, device drivers, executable libraries, and / or one or more application programs, which may include computer programs provided by various embodiments as described herein and / or may be designed to implement methods and / or configure systems provided by other embodiments. By way of example only, one or more procedures described with respect to the method(s) discussed above may be implemented as code and / or instructions in the memory 1660 that are executable by the UE 1600 (and / or the processor(s) 1610 or DSP 1620 within the UE 1600). In some embodiments, such code and / or instructions may then be used to configure and / or adapt a general-purpose computer (or other device) to perform one or more operations in accordance with the described methods.

[0201] FIG. 17 is a block diagram of one embodiment of a computer system 1700 that may be used in whole or in part to provide the functionality of one or more components and / or devices as described in the embodiments herein (including location servers such as the LMF, AMF, NEF, and GMLC). This may include, for example, a computer server, a personal computer, a personal electronic device, etc. Note that FIG. 17 is intended only to provide a generalized illustration of various components, any or all of which may be utilized as desired. Thus, FIG. 17 broadly illustrates how individual system elements may be implemented in a relatively separate or relatively more integrated manner. Additionally, note that the components illustrated in FIG. 17 may be localized in a single device and / or distributed among various networked devices that may be located in different geographic locations.

[0202] Computer system 1700 is shown including hardware elements that may be electrically coupled (or may otherwise communicate as needed) via a bus 1705. The hardware elements may include processor(s) 1710, which may include, but are not limited to, one or more general-purpose processors, one or more special-purpose processors (such as digital signal processing chips, graphics acceleration processors, etc.), and / or other processing structures that may be configured to perform one or more of the methods described herein. Computer system 1700 may also include one or more input devices 1715, which may include, but are not limited to, a mouse, keyboard, camera, microphone, etc., and one or more output devices 1720, which may include, but are not limited to, a display device, printer, etc.

[0203] Computer system 1700 may further include (and / or communicate with) one or more non-transitory storage devices 1725, which may comprise, but are not limited to, local and / or network-accessible storage, and / or may comprise, but are not limited to, disk drives, drive arrays, optical storage devices, solid-state storage devices such as random access memory (RAM) and / or read-only memory (ROM), which may be programmable, flash-updateable, etc. Such storage devices may be configured to implement any suitable data store, including, but not limited to, various file systems, database structures, etc. Such data stores may include database(s) and / or other data structures used to store and manage messages and / or other information to be sent to one or more devices via the hub, as described herein.

[0204] The computer system 1700 may also include a communications subsystem 1730, which may include wireless communications technologies managed and controlled by a wireless communications interface 1733, as well as wired technologies (such as Ethernet, coaxial communications, and universal serial bus (USB)). The wireless communications interface 1733 may include one or more wireless transceivers that may transmit and receive wireless signals 1755 (e.g., signals according to 5G NR or LTE) via wireless antenna(s) 1750. Thus, the communications subsystem 1730 may comprise a modem, a network card (wireless or wired), an infrared communications device, a wireless communications device, and / or a chipset, etc., which may enable the computer system 1700 to communicate in any or all of the communications networks described herein to any device on the respective network, including user equipment (UE), base stations, and / or other transmission / reception points (TRPs), and / or any other electronic device described herein. Thus, the communications subsystem 1730 may be used to receive and transmit messages and data as described in the embodiments herein.

[0205] In many embodiments, computer system 1700 will further include working memory 1735, which may include a RAM device or a ROM device, as described above. Software elements shown as residing in working memory 1735 may include other code, such as an operating system 1740, device drivers, executable libraries, and / or one or more applications 1745, which may include computer programs provided by various embodiments and / or may be designed to implement methods and / or configure systems provided by other embodiments, as described herein. By way of example only, one or more procedures described with respect to the method(s) described above may be implemented as code and / or instructions executable by a computer (and / or a processor within a computer), and in one aspect, such code and / or instructions may then be used to configure and / or adapt a general-purpose computer (or other device) to perform one or more operations in accordance with the described method.

[0206] A set of these instructions and / or code may be stored on a non-transitory computer-readable storage medium, such as storage device(s) 1725 described above. In some cases, the storage medium may be incorporated within a computer system, such as computer system 1700. In other embodiments, the storage medium may be separate from the computer system (e.g., a removable medium such as an optical disk) and / or provided in an installation package, such that the storage medium may be used to program, configure, and / or adapt a general-purpose computer with the instructions / code stored thereon. These instructions may be in the form of executable code that can be executed by computer system 1700 and / or may be in the form of source and / or installable code that, when compiled and / or installed on computer system 1700 (e.g., using any of a variety of publicly available compilers, installation programs, compression / decompression utilities, etc.), is then in the form of executable code.

[0207] Periodic and triggered Sidelink Mobile Terminated Location Request (SL-MT-LR) procedures may be used to estimate the relative location or distance and / or direction between UEs periodically or following some triggering event.

[0208] A seventh enhanced procedure for sidelink positioning / ranging may include a periodic or triggered SL-MT-LR procedure for ranging between target UEs. This procedure may enable an LCS client or AF to request and obtain sidelink positioning / ranging location information for two or more target UEs whenever a triggering or periodic event is detected by the UE.

[0209] Figure 18 illustrates a periodic or triggered SL-MT-LR procedure for enabling an LCS client or AF to obtain ranging / sidelink positioning location results for a group of n UEs (n≧2), i.e., UE1, UE2, ... UEn, periodically or upon the occurrence of a triggering event, according to some embodiments. In this procedure, the GMLC decides to designate one UE of the n UEs as UE1 (e.g., primary target UE) and one or more other UEs as UE2, UE3, ... UEn (n≧2) (e.g., target UEs, reference UEs, or located UEs). The ranging / sidelink positioning location results may include absolute location, relative location, range, direction, velocity, and relative speed associated with the UEs based on a service request. According to some embodiments, the procedure of Figure 18 may be used when at least one of the n UEs is in-coverage and registered with the serving PLMN. Details regarding the various steps of the procedure of Figure 18 are described in the following paragraphs.

[0210] According to some embodiments, as a prerequisite for the seventh extension procedure of FIG. 18, at least one of the n target UEs (here assumed to be UE1) is in coverage and can be registered with the serving PLMN.

[0211] Step 1: The LCS client or AF (via the NEF) may send an LCS service request to the (H)GMLC for ranging / sidelink positioning location results for n UEs, each of which may be identified by a GPSI or SUPI. The request may include the required QoS, the required location results (e.g., absolute location, relative location, velocity and / or distance and / or direction associated with the UE).

[0212] The service request may further include periodic or trigger event parameters. In the case of periodic location, the LCS service request may include the time interval between successive location reports and the total number of reports. In the case of triggered location, the LCS service request may include details of the trigger event, the duration of the event report, the minimum and maximum time intervals between successive event reports, the maximum event sampling interval, whether a location estimate should be included in the event report, whether only one location report is required, whether two or more location reports are required, or any combination thereof. The trigger event is (i) a ranging event, where the trigger event occurs when the range threshold and threshold type (type a, b, c, or d as follows) between at least one of the n UEs and each of the other n-1 UEs is such that any range for one UE is below the threshold (type a), any range for one UE is above the threshold (type b), all ranges for one UE are below the threshold (type c), or all ranges for one UE are above the threshold (type d); and (ii) a radial velocity threshold. and a threshold type (type a, b, c, or d as follows), i.e., a radial velocity event where a trigger event occurs when the radial velocities between at least one of the n UEs and each of the other n−1 UEs are such that any radial velocity for one UE is below a threshold (type a), any radial velocity for one UE is above a threshold (type b), all radial velocities for one UE are below a threshold (type c), or all radial velocities for one UE are above a threshold (type d). Note that the radial velocity between the first and second UEs may be equal to the rate of change of range (i.e., distance) between the first and second UEs. Other possible types of trigger events may be as described with respect to stage 1 of FIG. 13.

[0213] A preferred ordering for the n target UEs may be indicated by the LCS client or AF to assist in determining a primary target UE in stage 3. The (H)GMLC may modify any preferred ordering provided by the LCS client or AF. For example, the (H)GMLC may prioritize UEs whose PLMN of the (H)GMLC is the UE's Home PLMN (HPLMN). The request may also include a condition for canceling the location request when all n target UEs cannot be discovered for positioning. The conditions for canceling the location request may include (i) one or more specific target UEs cannot be discovered, and / or (ii) the total number of discovered target UEs is less than a quorum q, where 2≦q≦n.

[0214] The LCS client or AF may determine that all n target UEs are in proximity to one another and may obtain their application layer IDs and / or global IDs prior to stage 1. For example, one or more of the n target UEs may be in communication with the LCS client or AF (e.g., using an application protocol such as Hypertext Transfer Protocol (HTTP) or HTTP Secure (HTTPS)) and may provide the LCS client or AF with the application layer IDs and / or global IDs of all n target UEs and the approximate (coarse) relative or absolute location of each of the n target UEs, and / or may indicate whether the n target UEs have performed mutual discovery (e.g., if one target UE has discovered the other n−1 target UEs). This may allow the LCS client or AF to provide an LCS service request in stage 1 and know in advance that the n target UEs are in proximity to one another.

[0215] The (H)GMLC or NEF may authorize the LCS client or AF for use of the LCS service. If authorization fails, the remaining steps may be skipped and the (H)GMLC or NEF may respond to the LCS client or AF with a service authorization failure.

[0216] Additionally, an application layer ID may be included by the LCS client or AF for each of the n UEs to enable discovery of the UEs in step 12.

[0217] Step 2: (H)GMLC may invoke the Nudm_SDM_Get service operation towards the UDM of each of the n UEs to obtain the privacy settings of the UE identified by its GPSI or SUPI. The UDM may return the UE privacy settings of the UE. (H)GMLC checks the UE LCS privacy profile.

[0218] Step 3: The (H)GMLC may invoke a Nudm_UECM_Get service operation towards the UDM of each of the n UEs (for which a GPSI or SUPI is available), one at a time, using the GPSI or SUPI of each UE. In some embodiments, the (H)GMLC may invoke a Nudm_UECM_Get service operation towards the UDM of each of the n target UEs, one at a time, according to the preferred ordering in step 1 (if included). If any target UE is in coverage and registered with the serving PLMN, the UDM may return the network address of the current serving AMF and also the address of a visited GMLC (V-GMLC) for roaming UEs. The (H)GMLC may stop the Nudm_UECM_Get service operation towards the UDM(s) as soon as the UDM returns either the serving PLMN and AMF information for one of the n target UEs, or the serving PLMN and AMF information for one of the n target UEs indicating that one of the target UEs is served by the (H)GMLC's PLMN. This one UE may be treated as the primary target UE, and may here be treated as UE1. According to some embodiments, the UDM may know the serving AMF address at the time of UE registration to AMF and / or the serving V-GMLC address at the time of UE registration to AMF.

[0219] According to some embodiments, the UDM may know the serving AMF address at the time of UE registration to the AMF. The UDM may also know the serving V-GMLC address at the time of UE registration to the AMF.

[0220] Step 4: In the non-roaming case, this step may be skipped. In the roaming case, the (H)GMLC may receive the V-GMLC's address (along with the network address of the current serving AMF) from the UDM in step 3; otherwise, the (H)GMLC may use the NRF service to select an available V-GMLC in the VPLMN based on the VPLMN identification information included in the AMF address received in step 3. The (H)GMLC then sends a location request to the V-GMLC by invoking the Ngmlc_Location_ProvideLocation service operation toward the V-GMLC. The (H)GMLC may also include a contact address for the (H)GMLC (which may be called a notification target address and may be a uniform resource identifier (URI)) and a location deferral request (LDR) reference number (which may be called a notification correlation ID) to be used for event reporting in steps 24-31. The LDR reference number may be allocated by the (H-)GMLC based on predefined rules, e.g., operator policies, or may be allocated by the NEF. If the (H)GMLC did not receive the address of the V-GMLC, or if the V-GMLC address is the same as the (H)GMLC address, or if both PLMN operators agree, the (H)GMLC may send a Location Service Request message to the Serving AMF. In some cases, step 4 may be skipped. The (H)GMLC may also provide the AF of the LCS client type, if received in step 1, or the LCS client and other attributes of the LCS client type, which are sent to the AMF in step 5.

[0221] Step 5: In case of roaming, the V-GMLC may first allow location requests to be allowed from this (H)GMLC, PLMN, or this country. Otherwise, it may return an error response. The (H)GMLC or V-GMLC may invoke the Namf_Location_ProvidePositioningInfo service operation towards the AMF to request periodic or triggered sidelink positioning / ranging location results for n UEs. The service operation may include SUPI of UE1, the application layer ID of the UE determined by the (H)GMLC or V-GMLC to participate in the procedure, the LCS client type, the required LCS QoS, the required location result (e.g., relative location, speed or range, and direction associated with the UE), periodic or trigger event parameters, other attributes received or determined in steps 1 and 4, or any combination thereof.

[0222] According to some embodiments, the location request may be sent to one V-GMLC in stage 4 for roaming and to one AMF in stage 5 which is the serving AMF for UE1.

[0223] In step 6, if UE1 is in CM idle state, the AMF may initiate a network-triggered service request procedure to establish a signaling connection with UE1.

[0224] If the signaling connection establishment fails, steps 7 to 17 may be skipped.

[0225] Steps 7-8: For example, the NAS location notification call request and return result exchange may be performed as described with respect to steps 7 and 8 of FIG.

[0226] Step 9: The serving AMF can select an LMF serving UE1 (e.g., an LMF that supports ranging / sidelink positioning for periodic and triggered location) and can send an Nlmf_Location_DetermineLocation service operation to the LMF together with the information received in step 5, e.g., the required location result (e.g., relative location, speed, or range and direction between a pair of UEs) and periodic or trigger event parameters.

[0227] Step 10: The LMF may send a periodic-triggered SL-MT-LR request as a supplementary service message to the serving AMF using the Namf_Communication_N1N2MessageTransfer service operation and a correlation ID identifying the LMF or the location request (e.g., if a correlation ID has been assigned by the AMF and sent to the LMF in step 9). The LCS periodic-triggered SL-MT-LR request may include a deferred routing identifier, which may be the identification of the LMF when the LMF acts as the serving LMF, or a default LMF identification otherwise. The LCS periodic-triggered SL-MT-LR request may indicate the allowed access types (e.g., one or more of NR, LTE, WiFi, NR, or LTE satellite access) for the event reporting in step 24 and may include the QoS and allowed or required location results in step 24 for each reported location event. The LCS periodic-triggered SL-MT-LR request may also include the application layer ID of UE 1-n, a contact address for (H)GMLC, and an LDR reference number.

[0228] Step 11: The serving AMF may forward the periodically-triggered SL-MT-LR request and an immediate routing ID equal to the correlation ID to UE1 using a DL NAS transport message. According to some embodiments, the deferred routing identifier may be global (e.g., an IP address, a universally unique identifier (UUID), or a URI) or may be local. The deferred routing identifier may be used for routing in steps 24 and 25. The immediate routing identifier included by the AMF in step 11 may be used for routing in steps 14 and 15.

[0229] Step 12: UE1 may try to discover other UE2-n using their application layer IDs, and may discover them if they have not been discovered yet.

[0230] Step 13: UE1 may acquire the sidelink positioning capabilities of the discovered UEs if not already acquired.

[0231] Step 14: UE1 may return a supplementary service periodic-triggered SL-MT-LR response to the serving AMF in a UL NAS transport message and may include the immediate routing ID received in step 11. The periodic-triggered SL-MT-LR response may indicate whether periodic or triggered SL-MT-LR requests can be supported and which of UE2-n have been discovered and are available for positioning.

[0232] Step 15: The serving AMF may forward the periodic-triggered SL-MT-LR response to the LMF indicated by the immediate routing ID received in step 14, and may include a correlation ID equal to the immediate routing ID.

[0233] Step 16: Ranging / sidelink positioning of UE1 and other discovered UEs may occur for SL-MO-LR as described with respect to steps 10-18 of Figure 14, with the difference that the ranging / sidelink positioning location result may always be obtained and the LMF may indicate to UE1 in step 13 or step 14 of Figure 14 whether the ranging / sidelink positioning location result is calculated by the LMF (in step 18 of Figure 14) or by UE1 (in step 16 of Figure 14). According to some embodiments, step 16 (of Figure 18) may enable the LMF to obtain capabilities and initial location results for UE1-n.

[0234] Steps 17-20: The LMF may return the initial sidelink positioning / ranging location result to the LCS client or AF via the serving AMF, V-GMLC (if included), (H)GLMC, and NEF in case of AF.

[0235] Step 21: UEs 1-n may periodically perform sidelink positioning / ranging to support steps 22 and 24. According to some embodiments, UEs 1-n may perform sidelink positioning / ranging at intervals of the maximum event sampling interval provided in step 1.

[0236] In step 22, UE1 may monitor for the occurrence of trigger or periodic events requested during step 11. In the case of trigger events, UE1 may monitor the requested events at intervals equal to or less than the maximum event sampling interval. An event trigger may be detected by UE1 when any one or more of the following occurs: (i) a requested aperiodic trigger event is detected and the minimum reporting time interval has elapsed since the last report (if this is not the first event report); (ii) a requested periodic location event has occurred; or (iii) the maximum reporting time for the aperiodic trigger event has expired (since the last event report was sent in step 24 or from the start of the event report if this is the first event). If a trigger or periodic event is detected and UE1 is camped on or connected to (or has access to) an access type allowed by the LMF in step 11, UE1 may proceed to step 23. If UE1 is unable to access the permitted access type, UE1 may skip reporting the trigger event according to the requirements received from the LMF in step 11, or may report the trigger event at a later time when the permitted access type becomes available.

[0237] Step 23: UE1 may execute a UE triggered service request when in CM-IDLE state to establish a signaling connection with AMF.

[0238] Step 24: UE1 may send a supplementary service event report message to the serving AMF (which may be different from the serving AMF in steps 11 to 16) using the Namf_Communication_N1N2MessageTransfer service operation, and may include the deferred routing ID received in step 11. The event report may indicate the type of event being reported (e.g., whether it is a normal event or the expiration of the maximum reporting interval) and may include the location result obtained in step 21. UE1 may also include the (H)GMLC contact address, the LDR reference number, whether the location result should be reported, and if so, the location QoS in the event report, or any combination thereof.

[0239] Step 25: The AMF may forward the event report to the LMF indicated by the deferred routing ID received in step 24, and may include a correlation ID equal to the deferred routing ID.

[0240] Step 26: When the LMF receives the event report, and if the LMF can handle this event report, the LMF may update the status of the event report (e.g., the number of event reports received so far from UE1 and / or the duration of the event reports so far) and may return an additional service acknowledgment for the event report to the serving AMF using the Namf_Communication_N1N2MessageTransfer service operation and a correlation ID identifying the LMF. This acknowledgment may optionally include a new deferred routing identifier indicating the new serving LMF or the default (any) LMF.

[0241] Step 27: The serving AMF may forward the event report acknowledgment and an immediate routing ID equal to the correlation ID to UE1 using a DL NAS transport message. If UE1 does not receive any response from the LMF after a predefined time, e.g., if the current LMF does not support the deferred location request (for temporary or permanent reasons) or due to some radio access failure, UE1 may retransmit the report one or more times. According to some embodiments, including a new deferred routing identifier in the event report acknowledgment in step 26 may be used to change the serving LMF (e.g., if the UE moves to an area or access type better supported by a different LMF, or if the serving LMF is overloaded) or to allow a default LMF to become the serving LMF.

[0242] Step 28: If the location result is used for event reporting and not received in step 25, the LMF may trigger ranging / sidelink positioning of UE1-m as in step 16.

[0243] Steps 29-31: The LMF may return the event report and any location results obtained in step 25 or step 28 to the LCS client or AF via the serving AMF, V-GMLC (if included), (H)GLMC, and NEF in the case of AF.

[0244] Step 32: UE1-n may continue to periodically perform sidelink positioning / ranging as in step 21.

[0245] Step 33: UE1 may continue to monitor for further periodic or trigger events as in step 22, and may trigger steps 23-31 each time a periodic or trigger event is detected. For example, further periodic or trigger events may be detected at each of a series of different times, whereby steps 23-31 may be performed at each of a series of different times.

[0246] The descriptions of sidelink positioning up to this point have not indicated a specific positioning method or have assumed and referenced positioning based on SL PRS transmissions and measurements by participating UEs. However, the procedures described herein for MO-LR, MT-LR, or periodic or triggered MT-LR requests for SL positioning of multiple UEs can alternatively use other positioning methods. These may, in some embodiments, be radio access technology (RAT)-independent positioning methods. These other positioning methods may include real-time kinematics (RTK), transmission and measurement of WiFi signals by participating UEs, and transmission and measurement of ultra-wideband (UWB) signals by participating UEs. For example, when sidelink positioning of multiple UEs is performed using RTK, each UE of the multiple UEs may measure and obtain carrier phase measurements of global navigation satellite (GNSS) signals (e.g., for GPS, Galileo, GLONASS, or Beidou). The carrier phase measurements obtained by the multiple UEs may then be provided to at least one UE (e.g., UE1) of the multiple UEs, where the at least one UE determines location results for the multiple UEs based on the carrier phase measurements obtained by the multiple UEs. The use of RTK (or WiFi or UWB) rather than SL PRS may have little impact on how MO-LR, MT-LR, or periodic or triggered MT-LR requests for SL positioning of the multiple UEs are supported, except that MO-LR, MT-LR are no longer required for SL positioning of the multiple UEs; instead, other assistance data may be transmitted to the UE, such as configurations transmitted or measured for WiFi or UWB signals, or details of GNSS signals measured (but not transmitted) for RTK. Also, it is no longer necessary to transmit and measure SL PRS; instead, either WiFi or UWB signals may be transmitted and measured, or, in the case of RTK, RTK signals may be measured (but not transmitted).These changes require some modifications to Figures 10-15 and 18, but otherwise allow the inherent steps to remain for MO-LR, MT-LR, or periodic or triggered MT-LR requests for SL positioning of multiple UEs.

[0247] FIG. 19 is a diagram of an embodiment of a method 1900 performed at a location server to support sidelink positioning of multiple UEs (e.g., UE 105), according to one embodiment. The location server may comprise, for example, an LMF (e.g., LMF 120) as described herein. Aspects of method 1900 may reflect functionality of location servers described in various embodiments herein, such as those shown in FIGS. 11-15 and 18. The means and / or structures for performing the functions of one or more of the illustrated blocks in FIG. 19 may comprise software and / or hardware components of a computer system, such as computer system 1700 of FIG. 17.

[0248] The functions in block 1910 include receiving a request for location-related information for a plurality of UEs, the request associated with a first UE of the plurality of UEs, and the request based on one of (i) a mobile-originated location request (MO-LR) sent by the first UE, or (ii) a mobile-terminated location request (MT-LR) or a periodic or triggered MT-LR sent by an external client (e.g., external client 130, LCS client, or AF). The means and / or structure for performing the functions in block 1910 may include one or more processors 1710, memory 1735, communication subsystem 1730, and / or other components of computer system 1700, as described in FIG. 17 .

[0249] The functions at block 1920 include obtaining capability information for each UE of the plurality of UEs from a first UE of the plurality of UEs. The means and / or structure for performing the functions at block 1920 may include one or more processors 1710, memory 1735, communication subsystem 1730, and / or other components of computer system 1700, as described in FIG.

[0250] The functionality of block 1930 includes obtaining location-related information. The means and / or structures for performing the functionality in block 1930 may include one or more processors 1710, memory 1735, communication subsystem 1730, and / or other components of computer system 1700, as described in FIG.

[0251] The functions in block 1940 include transmitting location-related information, where transmitting includes one of: transmitting the location-related information to the first UE in response to the request for the location-related information being (i) based on MO-LR, where the location-related information supports sidelink positioning of multiple UEs; or transmitting the location-related information to an external client in response to the request for the location-related information being (ii) based on MT-LR or periodic or triggered MT-LR, where the location-related information is based on sidelink positioning of the multiple UEs. Means and / or structures for performing the functions in block 1940 may include one or more processors 1710, memory 1735, communication subsystem 1730, and / or other components of computer system 1700, as described in FIG. 17 .

[0252] As described herein, embodiments may include one or more of the following features: In some embodiments, the location server may not communicate with any UEs of the plurality of UEs other than the first UE for sidelink positioning of the plurality of UEs; the location-related information may include one or more location results for sidelink positioning of the plurality of UEs, the location results including one of: a range between a pair of UEs of the plurality of UEs, a direction between one UE and another UE of the plurality of UEs, a location of the one UE of the plurality of UEs, a location of the one UE relative to a location of another UE of the plurality of UEs, a velocity of the one UE of the plurality of UEs, or a velocity of the one UE relative to the velocity of another UE of the plurality of UEs. In such embodiments, the location-related information may include at least one location result for each UE of the plurality of UEs. Additionally or alternatively, obtaining the location-related information may include sending a request for location measurements to the first UE, where the first UE coordinates sidelink positioning of a plurality of UEs based on the request for location measurements, and the first UE obtains the location measurements based on the sidelink positioning of the plurality of UEs, receiving the location measurements from the first UE, and calculating the location-related information based on the location measurements. According to some embodiments, obtaining the location-related information may include sending a request for location-related information to the first UE, where the first UE coordinates sidelink positioning of a plurality of UEs based on the request for location-related information, and the first UE obtains the location-related information based on the sidelink positioning of the plurality of UEs, and receiving the location-related information from the first UE.

[0253] Additionally or alternatively, embodiments may include one or more of the following features. According to some embodiments, each UE of the plurality of UEs may comprise a target UE. The request may be based on (i) the MO-LR transmitted by the first UE, and the location-related information includes assistance data. Such embodiments may further include receiving a request for specific assistance data from the first UE, determining the specific assistance data based at least in part on the request for the specific assistance data and / or capability information of each UE of the plurality of UEs, and transmitting the specific assistance data to the first UE, the specific assistance data enabling sidelink positioning of the plurality of UEs. The request for location-related information may include application layer identification information for each UE of the plurality of UEs. The request may be based on (ii) an MT-LR or a periodic or triggered MT-LR sent by the external client, where the MT-LR or periodic or triggered MT-LR is received by the GMLC, and the GMLC determines the first UE based on at least one of: a preferred ordering of the UEs among the plurality of UEs indicated in the MT-LR or the periodic or triggered MT-LR sent by the external client; the first UE having the same home PLMN as the PLMN for the GMLC; or the first UE being served by the same home PLMN as the PLMN for the GMLC. According to some embodiments, the request may be based on a periodic or triggered MT-LR sent by the external client, where the periodic or triggered MT-LR includes a periodic event or a trigger event, where the trigger event is based on range or relative velocity of the UEs among the plurality of UEs. Such embodiments may further include obtaining location-related information at each of a series of different times and sending the location-related information in an event report to the external client at each of the series of different times. According to some embodiments, the request may be based on (ii) an MT-LR sent by an external client or a periodic or triggered MT-LR.

[0023] Embodiments may further include, before obtaining the capability information, sending to the first UE a separate MT-LR request or a periodic or triggered MT-LR request including identification information of the other UEs of the plurality of UEs to enable the first UE to discover the other UEs of the plurality of UEs based on the identification information of the other UEs of the plurality of UEs; and receiving from the first UE an MT-LR response or a periodic or triggered MT-LR response indicating whether the first UE has discovered the other UEs of the plurality of UEs and whether the other UEs of the plurality of UEs are available for sidelink positioning of the plurality of UEs.

[0254] Some embodiments may further include, before acquiring the capability information of each UE of the plurality of UEs, sending a capability request for the capability information of each UE of the plurality of UEs to the first UE, wherein acquiring the capability information of each UE of the plurality of UEs is in response to the capability request.

[0255] Figure 20 is a diagram of an embodiment of a method 2000 performed in a first UE (e.g., UE 105) to support sidelink positioning for multiple UEs, according to one embodiment. Aspects of method 2000 may reflect functionality of a UE as described in various embodiments herein, such as those shown in Figures 10-15 and 18. The means and / or structure for performing the functionality of one or more of the blocks illustrated in Figure 20 may comprise software and / or hardware components of a UE, such as, for example, the UE 1600 of Figure 16.

[0256] The functions in block 2010 include performing operations comprising one of: (i) sending an MO-LR request for location-related information toward a location server (e.g., LMF 120), or (ii) receiving an MT-LR request or a periodic or triggered MT-LR request for location-related information from a location server. The means and / or structure for performing the functions in block 2010 may comprise one or more processors 1610, memory 1660, wireless communication interface 1630, and / or other components of the UE 1600, as described in FIG. 16 .

[0257] The functions in block 2020 include discovering other UEs of the plurality of UEs. This may involve a discovery process described herein, which may be governed by the applicable wireless standard. The means and / or structure for performing the functions in block 2020 may comprise one or more processors 1610, memory 1660, wireless communication interface 1630, and / or other components of the UE 1600, as described in FIG. 16 .

[0258] The functions in block 2030 include obtaining capability information for each UE of the plurality of UEs, which may involve capability exchange, as described herein. The means and / or structure for performing the functions in block 2030 may comprise one or more processors 1610, memory 1660, wireless communication interface 1630, and / or other components of the UE 1600, as described in FIG. 16 .

[0259] The functions in block 2040 include transmitting capability information of each UE of the plurality of UEs to the location server. The means and / or structure for performing the functions in block 2040 may comprise one or more processors 1610, memory 1660, wireless communication interface 1630, and / or other components of the UE 1600, as described in FIG.

[0260] The functions at block 2050 include receiving a message from a location server, the message based at least in part on capability information of each UE of the plurality of UEs. The means and / or structure for performing the functions at block 2050 may comprise one or more processors 1610, memory 1660, wireless communication interface 1630, and / or other components of the UE 1600, as described in FIG.

[0261] The functionality in block 2060 includes coordinating sidelink positioning of the plurality of UEs based at least in part on the message. The means and / or structure for performing the functionality in block 2060 may comprise one or more processors 1610, memory 1660, wireless communication interface 1630, and / or other components of the UE 1600, as described in FIG. 16 .

[0262] The functions in block 2070 include obtaining location measurements, location results, or both based on sidelink positioning of the plurality of UEs. The means and / or structure for performing the functions in block 2070 may comprise one or more processors 1610, memory 1660, wireless communication interface 1630, and / or other components of the UE 1600, as described in FIG. 16 .

[0263] The functions in block 2080 include sending the location measurements or location results to a location server when the message includes a request for the location measurements or location results, and the location server calculating the location result based on the location measurements when the first UE sends the location measurements to the location server. The means and / or structure for performing the functions in block 2080 may comprise one or more processors 1610, memory 1660, wireless communication interface 1630, and / or other components of the UE 1600, as described in FIG. 16 .

[0264] As described herein, according to some embodiments, the location-related information may include location results, where the location results include one or more of: a range between a pair of UEs of the plurality of UEs; a direction between one UE and another UE of the plurality of UEs; a location of one UE of the plurality of UEs; a location of one UE relative to a location of another UE of the plurality of UEs; a velocity of one UE of the plurality of UEs; or a velocity of one UE relative to a velocity of another UE of the plurality of UEs. The location results may include at least one location result for each UE of the plurality of UEs. According to some embodiments, each UE of the plurality of UEs includes a target UE.

[0265] As described herein, embodiments may include one or more of the following features. In some embodiments, the location server may not communicate with any UEs of the plurality of UEs other than the first UE for sidelink positioning of the plurality of UEs. According to some embodiments, the message may include a request for location measurements or location results, and method 2000 may further include transmitting the location measurements or location results to the location server in response to the request for location measurements or location results. According to some embodiments, the first UE performs operations including (i) transmitting a MO-LR request for location-related information, the location-related information including assistance data. Such embodiments may further include sending a request for specific assistance data to the location server, the location server determining the specific assistance data based at least in part on the request for specific assistance data and / or capability information of each UE of the plurality of UEs, and receiving the specific assistance data from the location server in the message, the specific assistance data enabling sidelink positioning of the plurality of UEs.

[0266] According to some embodiments, the first UE performs operations including (ii) receiving an MT-LR request or a periodic or triggered MT-LR request for the location-related information, wherein the MT-LR request or the periodic or triggered MT-LR request for the location-related information includes application layer identification information for each UE of the plurality of UEs, and wherein discovering other UEs of the plurality of UEs is based on the application layer identification information for each UE of the plurality of UEs.

[0267] According to some embodiments, the first UE may perform operations including (i) sending an MO-LR request for location-related information, the method further including: obtaining application layer identification information for each UE of the plurality of UEs based on discovering other UEs of the plurality of UEs; and including the application layer identification information for each UE of the plurality of UEs in the MO-LR request for location-related information.

[0268] Additionally or alternatively, embodiments may include one or more of the following features: According to some embodiments, the first UE may perform operations including (ii) receiving an MT-LR request or a periodic or triggered MT-LR request, wherein a separate request for an MT-LR or periodic or triggered MT-LR sent by an external client (e.g., external client 130, an LCS client, or an AF) is received by a GMLC (e.g., GMLC 125), and the GMLC determines the first UE based on at least one of a preferred ordering of UEs among multiple UEs indicated in the request for the MT-LR or periodic or triggered MT-LR, the first UE having the same home PLMN as the PLMN for the GMLC, or the first UE being served by the same home PLMN as the PLMN for the GMLC.

[0269] According to some embodiments, the first UE may perform operations including (ii) receiving an MT-LR request or a periodic or triggered MT-LR request, where the MT-LR request includes a periodic or triggered MT-LR request, where the periodic or triggered MT-LR request includes a periodic event or a trigger event, where the trigger event is based on a range or relative velocity of the UE of the plurality of UEs. Some embodiments may further include detecting the periodic event or the trigger event at each of a series of different times, obtaining location measurements or location results at each of the series of different times, and transmitting the location measurements or location results in an event report to the location server at each of the series of different times.

[0270] According to some embodiments, the first UE may perform operations including (ii) receiving an MT-LR request or a periodic or triggered MT-LR request, the method further including sending an MT-LR response or a periodic or triggered MT-LR response to the location server, the MT-LR response or the periodic or triggered MT-LR response indicating whether the first UE has discovered other UEs of the plurality of UEs, and the MT-LR response or the periodic or triggered MT-LR response indicating whether other UEs of the plurality of UEs are available for sidelink positioning of the plurality of UEs.

[0271] Some embodiments may further include, before obtaining the capability information for each UE of the plurality of UEs, receiving a request for the capability information for each UE of the plurality of UEs from the location server, wherein obtaining the capability information for each UE of the plurality of UEs is in response to the request for the capability information.

[0272] It will be apparent to those skilled in the art that substantial variations may be made according to particular requirements. For example, customized hardware might also be used and / or particular elements might be implemented in hardware, software (including portable software such as applets), or both. Furthermore, connection to other computing devices, such as network input / output devices, might be utilized.

[0273] With reference to the accompanying figures, components that may include memory may also include non-transitory machine-readable media. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any storage medium that participates in providing data that causes a machine to operate in a specific manner. In the embodiments provided above, various machine-readable media may participate in providing instructions / code to a processor and / or other device(s) for execution. Additionally or alternatively, machine-readable media may be used to store and / or transport such instructions / code. In many implementations, computer-readable media are physical and / or tangible storage media. Such media may take many forms, including, but not limited to, non-volatile media and volatile media. Common forms of computer-readable media include, for example, magnetic and / or optical media, any other physical media with a pattern of holes, RAM, programmable ROM (PROM), erasable PROM (EPROM), FLASH-EPROM, any other memory chip or cartridge, or any other medium from which a computer can read instructions and / or code.

[0274] The methods, systems, and devices described herein are examples. Various embodiments may omit, substitute, or add various procedures or components, as appropriate. For example, features described with respect to some embodiments may be combined in various other embodiments. Different aspects and elements of the embodiments may be similarly combined. Various components of the diagrams provided herein may be embodied in hardware and / or software. Also, technology evolves, and therefore, many of the elements are examples that do not limit the scope of the disclosure to those specific examples.

[0275] It has proven convenient at times, principally for reasons of common usage, to refer to such signals as bits, information, values, elements, symbols, characters, variables, terms, numbers, numerical values, or the like. It should be understood, however, that all of these or similar terms are merely convenient labels and are to be associated with the appropriate physical quantities. Unless otherwise expressly stated, and as is clear from the above description, throughout this specification, descriptions utilizing terms such as "processing," "calculating," "calculating," "determining," "ascertaining," "identifying," "associating," "measuring," "performing," and the like, should be understood to refer to actions or processes of a particular apparatus, such as a special purpose computer or similar special purpose electronic computing device. Thus, in the context of this specification, a special purpose computer or similar special purpose electronic computing device is capable of manipulating or transforming signals that are typically represented as physical electronic, electrical, or magnetic quantities within the memories, registers, or other information storage, transmission, or display devices of the special purpose computer or similar special purpose electronic computing device.

[0276] The terms "and" and "or" as used herein may include a variety of meanings that are expected to depend, at least in part, on the context in which such terms are used. Generally, when "or" is used to associate a list, such as A, B, or C, it is intended to mean A, B, and C, which are used herein in an inclusive sense, as well as A, B, or C, which are used herein in an exclusive sense. Additionally, as used herein, the term "one or more" may be used to refer to any feature, structure, or characteristic in the singular, or may be used to refer to any combination of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example, and claimed subject matter is not limited to this example. Furthermore, the term "at least one of," when used to associate a list, such as A, B, or C, may be interpreted to mean any combination of A, B, and / or C, such as A, AB, AA, AAB, AABBCCC, etc.

[0277] While several embodiments have been described, various modifications, alternative configurations, and equivalents may be used without departing from the scope of the present disclosure. For example, the above elements may merely be components of a larger system in which other rules may take precedence over or otherwise modify the application of the various embodiments. Also, some steps may be taken before, during, or after the above elements are considered. Therefore, the above description does not limit the scope of the present disclosure.

[0278] Clause 1: A method performed in a location server for supporting sidelink positioning of a plurality of user equipments (UEs), the method comprising: receiving a request for location-related information for the plurality of UEs, the request being associated with a first UE of the plurality of UEs, the request being based on one of a Mobile Originated Location Request (MO-LR) sent by the first UE, or a Mobile Terminated Location Request (MT-LR) sent by an external client, or a periodic or triggered MT-LR; obtaining capability information of each UE of the plurality of UEs from the first UE of the plurality of UEs; and obtaining the location-related information. and transmitting location-related information, wherein the transmitting includes one of: (i) transmitting location-related information to a first UE in response to a request for location-related information based on a Mobile Node-Learning-Register (MO-LR), where the location-related information supports sidelink positioning of multiple UEs; or (ii) transmitting location-related information to an external client in response to a request for location-related information based on a Mobile Node-Learning-Register (MT-LR) or periodic or triggered MT-LR, where the location-related information is based on sidelink positioning of multiple UEs.

[0279] Clause 2: The method according to clause 1, wherein the location server does not communicate with any UE of the plurality of UEs other than the first UE for sidelink positioning of the plurality of UEs.

[0280] Clause 3: The method of clause 1 or 2, wherein the location-related information includes one or more location results for sidelink positioning of the plurality of UEs, the location results including one or more of: a range between a pair of UEs of the plurality of UEs; a direction between one UE and another UE of the plurality of UEs; a location of one UE of the plurality of UEs; a location of one UE relative to a location of another UE of the plurality of UEs; a velocity of one UE of the plurality of UEs; or a velocity of one UE relative to the velocity of another UE of the plurality of UEs.

[0281] Clause 4: The method of clause 3, wherein the location-related information includes at least one location result for each UE of the plurality of UEs.

[0282] Clause 5: The method of clause 3, wherein obtaining location-related information includes: sending a request for location measurements to a first UE, the first UE coordinating sidelink positioning of multiple UEs based on the request for location measurements, and the first UE obtaining location measurements based on the sidelink positioning of the multiple UEs; receiving the location measurements from the first UE; and calculating the location-related information based on the location measurements.

[0283] Clause 6: The method of clause 3, wherein obtaining the location-related information includes: sending a request for location-related information to a first UE, the first UE coordinating sidelink positioning of a plurality of UEs based on the request for location-related information, and the first UE obtaining the location-related information based on the sidelink positioning of the plurality of UEs; and receiving the location-related information from the first UE.

[0284] Clause 7: The method of any one of clauses 1 to 6, wherein each UE of the plurality of UEs is a target UE.

[0285] Clause 8: The method of any one of clauses 1 to 7, wherein the request is based on (i) the MO-LR sent by the first UE, and the location-related information includes assistance data.

[0286] Clause 9: The method of clause 8, further comprising: receiving a request for specific assistance data from a first UE; determining the specific assistance data based at least in part on the request for the specific assistance data and capability information of each UE of the plurality of UEs; and transmitting the specific assistance data to the first UE, the specific assistance data enabling sidelink positioning of the plurality of UEs.

[0287] Clause 10: The method of any one of clauses 1 to 9, wherein the request for location-related information includes application layer identification information for each UE of the plurality of UEs.

[0288] Clause 11: The method of any one of clauses 1 to 10, wherein the request is (ii) based on an MT-LR or a periodic or triggered MT-LR sent by an external client, wherein the MT-LR or periodic or triggered MT-LR is received by the GMLC, and the GMLC determines the first UE based on at least one of: a preferred ordering of UEs among multiple UEs indicated in the MT-LR sent by the external client or the periodic or triggered MT-LR; the first UE having the same home PLMN as the PLMN for the GMLC; or the first UE being served by the same home PLMN as the PLMN for the GMLC.

[0289] Clause 12: The method of any one of clauses 1 to 11, wherein the request is based on a periodic or triggered MT-LR sent by an external client, the periodic or triggered MT-LR including a periodic event or a trigger event, and the trigger event is based on a range or relative speed of a UE among a plurality of UEs.

[0290] Clause 13: The method of clause 12, further comprising obtaining location-related information at each of a series of different times, and transmitting the location-related information in an event report to an external client at each of the series of different times.

[0291] Clause 14: The method of any one of clauses 1 to 13, wherein the request further comprises: (ii) sending to the first UE a separate MT-LR request or periodic or triggered MT-LR request including identification information of the other UEs of the plurality of UEs to enable the first UE to discover other UEs of the plurality of UEs based on the identification information of the other UEs of the plurality of UEs based on the MT-LR or periodic or triggered MT-LR sent by the external client before obtaining the capability information; and receiving from the first UE an MT-LR response or periodic or triggered MT-LR response indicating whether the first UE has discovered the other UEs of the plurality of UEs and whether the other UEs of the plurality of UEs are available for sidelink positioning of the plurality of UEs.

[0292] Clause 15: A method according to any one of clauses 1 to 14, further comprising sending a capability request for the capability information of each UE of the plurality of UEs to the first UE before acquiring the capability information of each UE of the plurality of UEs, wherein acquiring the capability information of each UE of the plurality of UEs is in response to the capability request.

[0293] Clause 16: A method performed in a first UE of a plurality of UEs to support sidelink positioning of a plurality of UEs, the method comprising: performing operations including one of: (i) sending a MO-LR request for location-related information towards a location server; or (ii) receiving a MT-LR request or a periodic or triggered MT-LR request for location-related information from the location server; discovering other UEs of the plurality of UEs; obtaining capability information for each UE of the plurality of UEs; sending the capability information for each UE of the plurality of UEs to the location server; receiving a message from the location server, the message based at least in part on the capability information of each UE of the plurality of UEs; coordinating sidelink positioning of the plurality of UEs based at least in part on the message; obtaining location measurements, location results, or both based on the sidelink positioning of the plurality of UEs; and, when the message includes a request for location measurements or location results, sending the location measurements or location results to the location server, the location server calculating the location results based on the location measurements when the first UE sends the location measurements to the location server.

[0294] Clause 17: The method according to clause 16, wherein the location server does not communicate with any UE among the plurality of UEs other than the first UE for sidelink positioning of the plurality of UEs.

[0295] Clause 18: The method of clause 16 or 17, wherein the location-related information includes a location result, the location result including one or more of: a range between a pair of UEs among the plurality of UEs; a direction between one UE and another UE among the plurality of UEs; a location of one UE among the plurality of UEs; a location of one UE relative to a location of another UE among the plurality of UEs; a velocity of one UE among the plurality of UEs; or a velocity of one UE relative to the velocity of another UE among the plurality of UEs.

[0296] Clause 19: The method of clause 18, wherein the location results include at least one location result for each UE of the plurality of UEs.

[0297] Clause 20: The method of clause 18 or 19, wherein each UE of the plurality of UEs is a target UE.

[0298] Clause 21: A method according to any one of clauses 16 to 20, wherein the message includes a request for a location measurement or a location result, and further comprising sending the location measurement or the location result to a location server in response to the request for the location measurement or the location result.

[0299] Clause 22: The method of any one of clauses 16 to 21, wherein the first UE performs an operation including (i) sending an MO-LR request for location-related information, and the location-related information includes assistance data.

[0300] Clause 23: The method of clause 22, further comprising: sending a request for specific assistance data to a location server, the location server determining the specific assistance data based at least in part on the request for the specific assistance data and capability information of each UE of the plurality of UEs; and receiving the specific assistance data from the location server in a message, the specific assistance data enabling sidelink positioning of the plurality of UEs.

[0301] Clause 24: The method of any one of clauses 16 to 23, wherein the first UE performs an operation including (ii) receiving an MT-LR request or a periodic or triggered MT-LR request for location-related information, wherein the MT-LR request or the periodic or triggered MT-LR request for location-related information includes application layer identification information for each UE of the plurality of UEs, and discovering other UEs of the plurality of UEs is based on the application layer identification information for each UE of the plurality of UEs.

[0302] Clause 25: A method according to any one of clauses 16 to 24, wherein the first UE performs an operation including (i) sending an MO-LR request for location-related information, and the method further includes: obtaining application layer identification information for each UE of the plurality of UEs based on discovering other UEs of the plurality of UEs; and including the application layer identification information for each UE of the plurality of UEs in the MO-LR request for location-related information.

[0303] Clause 26: The method of any one of clauses 16 to 25, wherein the first UE performs an operation including (ii) receiving an MT-LR request or a periodic or triggered MT-LR request, and a separate request for an MT-LR or periodic or triggered MT-LR sent by an external client is received by the GMLC, and the GMLC determines the first UE based on at least one of a preferred ordering of UEs among multiple UEs indicated in the request for the MT-LR or periodic or triggered MT-LR, the first UE having the same home PLMN as the PLMN for the GMLC, or the first UE being served by the same home PLMN as the PLMN for the GMLC.

[0304] Clause 27: The method of any one of clauses 16 to 26, wherein the first UE performs an operation including (ii) receiving an MT-LR request or a periodic or triggered MT-LR request, wherein the MT-LR request includes a periodic or triggered MT-LR request, and wherein the periodic or triggered MT-LR request includes a periodic event or a trigger event, and wherein the trigger event is based on a range or relative speed of the UE among the plurality of UEs.

[0305] Clause 28: The method described in Clause 27, further comprising detecting a periodic event or a trigger event at each of a series of different times, obtaining location measurements or location results at each of the series of different times, and transmitting the location measurements or location results to a location server in an event report at each of the series of different times.

[0306] Clause 29: The method of any one of clauses 16 to 28, wherein the first UE performs operations including (ii) receiving an MT-LR request or a periodic or triggered MT-LR request, and the method further comprises sending an MT-LR response or a periodic or triggered MT-LR response to the location server, the MT-LR response or the periodic or triggered MT-LR response indicating whether the first UE has discovered other UEs of the plurality of UEs, and the MT-LR response or the periodic or triggered MT-LR response indicating whether other UEs of the plurality of UEs are available for sidelink positioning of the plurality of UEs.

[0307] Clause 30: The method of any one of clauses 16 to 29, further comprising receiving a request for capability information of each UE of the plurality of UEs from a location server before obtaining capability information of each UE of the plurality of UEs, and obtaining capability information of each UE of the plurality of UEs is in response to the request for capability information.

[0308] Clause 31: A location server for supporting sidelink positioning of a plurality of user equipments (UEs), the location server comprising: one or more transceivers; one or more memories; and one or more processors communicatively coupled to the one or more transceivers and the one or more memories, receiving, via the one or more transceivers, a request for location-related information for a plurality of UEs, the request being associated with a first UE of the plurality of UEs, the request being based on one of a Mobile Originated Location Request (MO-LR) sent by the first UE, or a Mobile Terminated Location Request (MT-LR) sent by an external client, or a periodic or triggered MT-LR; and transmitting, via the one or more transceivers, from the first UE of the plurality of UEs, a request for location-related information for each UE of the plurality of UEs. and one or more processors configured to: acquire capability information of a first UE, acquire location-related information, and transmit via one or more transceivers the location-related information, wherein the transmitting includes one of: transmitting location-related information to a first UE in response to a request for location-related information being (i) based on a Multiple Access-Region-Layer (MO-LR), where the location-related information supports sidelink positioning of multiple UEs; or (ii) transmitting location-related information to an external client in response to a request for location-related information based on a Multiple Access-Region-Layer (MT-LR) or periodic or triggered MT-LR, where the location-related information is based on sidelink positioning of multiple UEs.

[0309] Clause 32: The location server of clause 31, wherein the one or more processors are configured to not communicate with any UE of a plurality of UEs other than the first UE for sidelink positioning of the plurality of UEs.

[0310] Clause 33: The location server of clause 31 or 32, wherein the one or more processors are configured to include in the location-related information one or more location results for sidelink positioning of the plurality of UEs, the location results including one or more of: a range between a pair of UEs of the plurality of UEs, a direction between one UE and another UE of the plurality of UEs, a location of one UE of the plurality of UEs, a location of one UE relative to a location of another UE of the plurality of UEs, a velocity of one UE of the plurality of UEs, or a velocity of one UE relative to the velocity of another UE of the plurality of UEs.

[0311] Clause 34: The location server of clause 33, wherein to obtain the location-related information, the one or more processors are configured to obtain at least one location result for each UE of the plurality of UEs.

[0312] Clause 35: The location server of clause 33, wherein each UE of the plurality of UEs is a target UE.

[0313] Clause 36: To obtain the location-related information, the one or more processors are configured to: send a request for location measurements to a first UE, the first UE coordinating sidelink positioning of multiple UEs based on the request for location measurements; and the first UE obtaining location measurements based on the sidelink positioning of the multiple UEs; receive the location measurements from the first UE; and calculate the location-related information based on the location measurements.

[0314] Clause 37: To obtain the location-related information, the one or more processors are configured to: send a request for location-related information to a first UE, the first UE coordinating sidelink positioning of a plurality of UEs based on the request for location-related information; and receive the location-related information from the first UE.

[0315] Clause 38: A location server as described in any one of clauses 31 to 37, wherein in response to a request being based on (i) the MO-LR sent by the first UE to obtain location-related information, the one or more processors are configured to obtain assistance data.

[0316] Clause 39: The location server of Clause 38, wherein the one or more processors are further configured to: receive a request for specific assistance data from a first UE; determine the specific assistance data based at least in part on the request for the specific assistance data and capability information of each UE of the plurality of UEs; and transmit the specific assistance data to the first UE, the specific assistance data enabling sidelink positioning of the plurality of UEs.

[0317] Clause 40: A location server as described in any one of clauses 31 to 39, wherein, to receive a request for location-related information, the one or more processors are configured to receive application layer identification information for each UE of the plurality of UEs.

[0318] Clause 41: A location server as described in any one of clauses 31 to 40, wherein the one or more processors are configured to receive periodic or triggered MT-LR-based requests sent by an external client, the receiving including periodic events or trigger events, the trigger events being based on ranges or relative speeds of UEs among a plurality of UEs.

[0319] Clause 42: The location server of clause 41, wherein the one or more processors are further configured to obtain location-related information at each of a series of different times and transmit the location-related information to an external client in an event report at each of the series of different times.

[0320] Clause 43: The location server of any one of clauses 31 to 42, wherein the one or more processors are configured to: in response to the request being (ii) based on an MT-LR or a periodic or triggered MT-LR sent by the external client, send to the first UE a separate MT-LR request or a periodic or triggered MT-LR request including identification information of the other UEs of the plurality of UEs, to enable the first UE to discover the other UEs of the plurality of UEs based on the identification information of the other UEs of the plurality of UEs, before obtaining the capability information; and receive from the first UE an MT-LR response or a periodic or triggered MT-LR response indicating whether the first UE has discovered the other UEs of the plurality of UEs and whether the other UEs of the plurality of UEs are available for sidelink positioning of the plurality of UEs.

[0321] Clause 44: The location server described in any one of clauses 31 to 43, wherein the one or more processors are further configured to send a capability request for the capability information of each UE of the plurality of UEs to the first UE before acquiring the capability information of each UE of the plurality of UEs, and acquiring the capability information of each UE of the plurality of UEs is in response to the capability request.

[0322] Clause 45: A method for supporting sidelink positioning of a plurality of UEs, wherein a first UE of the plurality of UEs comprises one or more transceivers and one or more processors communicatively coupled to the one or more transceivers and one or more memories, the first UE performing operations including one of: (i) sending a MO-LR request for location-related information towards a location server; or (ii) receiving a MT-LR request or a periodic or triggered MT-LR request for location-related information from the location server; discovering other UEs of the plurality of UEs; obtaining capability information of each UE of the plurality of UEs; transmitting the capability information of each UE of the plurality of UEs to the location server; and receiving a message from the location server. and one or more processors configured to: receive a message, the message being based at least in part on capability information of each UE of the plurality of UEs; coordinate sidelink positioning of the plurality of UEs based at least in part on the message; obtain location measurements, location results, or both based on the sidelink positioning of the plurality of UEs; and, when the message includes a request for the location measurements or the location results, send the location measurements or the location results to a location server, the location server calculating a location result based on the location measurements when the first UE sends the location measurements to the location server.

[0323] Clause 46: The first UE described in Clause 45, wherein the location-related information includes a location result, the location result including one or more of: a range between a pair of UEs among the plurality of UEs; a direction between one UE and another UE among the plurality of UEs; a location of one UE among the plurality of UEs; a location of one UE relative to a location of another UE among the plurality of UEs; a velocity of one UE among the plurality of UEs; or a velocity of one UE relative to the velocity of another UE among the plurality of UEs.

[0324] Clause 47: The first UE of clause 46, wherein the location results include at least one location result for each UE of the plurality of UEs.

[0325] Clause 48: The first UE of any one of clauses 45 to 47, wherein each UE of the plurality of UEs is a target UE.

[0326] Clause 49: A first UE described in any one of clauses 45 to 48, wherein to receive the message, the one or more processors are configured to receive a request for location measurements or location results, and the one or more processors are further configured to send the location measurements or location results to a location server in response to the request for the location measurements or location results.

[0327] Clause 50: (i) A first UE as described in any one of clauses 45 to 49, wherein in order to perform an operation including sending an MO-LR request for location-related information, the one or more processors are configured to request assistance data.

[0328] Clause 51: The first UE described in Clause 50, wherein the one or more processors are further configured to send a request for specific assistance data to a location server, the location server determining the specific assistance data based at least in part on the request for the specific assistance data and capability information of each UE among the plurality of UEs, and to receive specific assistance data from the location server in a message, the specific assistance data enabling sidelink positioning of the plurality of UEs.

[0329] Clause 52: (ii) To perform the operations including receiving an MT-LR request or a periodic or triggered MT-LR request, the one or more processors are configured to receive application layer identification information for each UE of the plurality of UEs in the MT-LR request or the periodic or triggered MT-LR request for location-related information, and the one or more processors are configured to discover other UEs of the plurality of UEs based on the application layer identification information for each UE of the plurality of UEs.

[0330] Clause 53: A first UE described in any one of Clauses 45 to 52, wherein the one or more processors are configured to (i) obtain application layer identification information for each UE of the plurality of UEs based on discovering other UEs of the plurality of UEs before performing an operation including sending an MO-LR request for location-related information, and include the application layer identification information for each UE of the plurality of UEs in the MO-LR request for location-related information.

[0331] Clause 54: (ii) To perform the operations including receiving an MT-LR request or a periodic or triggered MT-LR request, the one or more processors are configured to receive a periodic or triggered MT-LR request, the periodic or triggered MT-LR request including a periodic event or a trigger event, and the trigger event is based on a range or relative speed of the UE among the plurality of UEs, the first UE described in any one of Clauses 45 to 53.

[0332] Clause 55: A first UE as described in any one of Clauses 45 to 54, wherein the one or more processors are further configured to detect a periodic event or a trigger event at each of a series of different times, obtain location measurements or location results at each of the series of different times, and transmit the location measurements or location results to a location server in an event report at each of the series of different times.

[0333] Clause 56: The first UE of Clause 55, wherein the one or more processors are configured to (ii) after performing the operation including receiving the MT-LR request or the periodic or triggered MT-LR request, send an MT-LR response or a periodic or triggered MT-LR response to the location server, the MT-LR response or the periodic or triggered MT-LR response indicating whether the first UE has discovered other UEs of the plurality of UEs, and the MT-LR response or the periodic or triggered MT-LR response indicating whether other UEs of the plurality of UEs are available for sidelink positioning of the plurality of UEs.

[0334] Clause 57: A first UE described in any one of clauses 45 to 56, wherein the one or more processors are further configured to receive a request for capability information of each UE of the plurality of UEs from the location server before obtaining the capability information of each UE of the plurality of UEs, and obtaining the capability information of each UE of the plurality of UEs is in response to the request for capability information.

[0335] 31. An apparatus having means for carrying out the method according to any one of clauses 1 to 30.

[0336] A non-transitory computer readable medium storing instructions including code for performing the method of any one of clauses 1 to 30.

Claims

1. A method performed on a location server to support sidelink positioning of multiple user devices (UEs), wherein the method is: Receiving a request for location-related information for the plurality of UEs, wherein the request is associated with a first UE among the plurality of UEs, (i) A mobile outgoing location request (MO-LR) transmitted by the first UE, (ii) Mobile incoming location requests (MT-LR) sent by an external client or periodic or triggered MT-LRs, Receiving based on one of the following, Obtaining capability information for each of the multiple UEs from the first UE among the multiple UEs, To obtain the aforementioned location-related information, Transmitting the aforementioned location-related information, and the transmission of the aforementioned information is (i) In response to the request for location-related information being based on MO-LR, transmit the location-related information to the first UE, wherein the location-related information supports sidelink positioning of the plurality of UEs, or (ii) In response to the request for location-related information being based on MT-LR or periodic or triggered MT-LR, transmitting the location-related information to the external client, wherein the location-related information is based on the sidelink positioning of the plurality of UEs. Transmitting the location-related information, including one of the following: A method comprising the following, wherein the request is based on the periodic or triggered MT-LR transmitted by the external client, the periodic or triggered MT-LR includes a periodic event or a trigger event, and the trigger event is based on a range or relative velocity of UEs among a plurality of UEs.

2. The method according to claim 1, wherein the location server does not communicate with any of the multiple UEs other than the first UE for the purpose of sidelink positioning of the multiple UEs.

3. The location-related information includes one or more location results for the sidelink positioning of the plurality of UEs, and the location results are The range between pairs of UEs among the aforementioned plurality of UEs, The direction between one UE and another UE among the aforementioned plurality of UEs, The location of one of the aforementioned multiple UEs, A location of one UE relative to the location of another UE among the aforementioned plurality of UEs, The speed of one of the aforementioned plurality of UEs, or The speed of one UE relative to the speed of another UE among the plurality of UEs, The method according to claim 1, comprising one or more of the above.

4. The method according to claim 3, wherein the location-related information includes at least one location result for each of the plurality of UEs.

5. Obtaining the aforementioned location-related information means The first UE transmits a request for location measurement values, the first UE adjusts the sidelink positioning of the plurality of UEs based on the request for location measurement values, and the first UE acquires and transmits the location measurement values ​​based on the sidelink positioning of the plurality of UEs. Receiving the location measurement from the first UE, Calculating the location-related information based on the location measurement values, The method according to claim 3, including the method described in claim 3.

6. Obtaining the location-related information means that Transmitting a request for location-related information to the first UE, wherein the first UE adjusts the sidelink positioning of the plurality of UEs based on the request for location-related information, and the first UE acquires and transmits the location-related information based on the sidelink positioning of the plurality of UEs. Receiving the location-related information from the first UE, The method according to claim 3, including the method described in claim 3.

7. The request is (i) based on the MO-LR transmitted by the first UE, the location-related information includes support data, and the method is Receiving a request for specific support data from the first UE, Determining the specific support data based at least partially on the request for the specific support data and the capability information of each of the plurality of UEs, Transmitting the specific support data to the first UE, wherein the specific support data enables the sidelink positioning of the plurality of UEs. The method according to claim 1, further comprising:

8. The method according to claim 1, wherein the request for location-related information includes application layer identification information for each of the plurality of UEs.

9. The request is (ii) based on the MT-LR or periodic or triggered MT-LR transmitted by the external client, the MT-LR or periodic or triggered MT-LR is received by the GMLC, and the GMLC Preferred ordering of the UEs among the plurality of UEs shown in the MT-LR transmitted by the external client or in the periodic or triggered MT-LR, The first UE has the same home PLMN as the PLMN for the GMLC, or The first UE is serviced by the same home PLMN as the PLMN for the GMLC. The method according to claim 1, wherein the first UE is determined based on at least one of the following.

10. Acquiring location-related information at each of a series of different times, Sending the location-related information to the external client in the event report at each of the aforementioned different time periods, The method according to claim 1, further comprising:

11. The request is based on (ii) the MT-LR transmitted by the external client or the periodic or triggered MT-LR, The aforementioned method, Transmitting a separate MT-LR request or a periodic or triggered MT-LR request to the first UE before acquiring the capability information, wherein the separate MT-LR request or the periodic or triggered MT-LR request includes identification information for the other UE among the plurality of UEs, enabling the first UE to discover the other UE among the plurality of UEs based on identification information for the other UE among the plurality of UEs. Receiving an MT-LR response or a periodic or triggered MT-LR response from the first UE, wherein the MT-LR response or the periodic or triggered MT-LR response indicates whether the first UE has discovered the other UE among the plurality of UEs, and whether the other UE among the plurality of UEs is available for the sidelink positioning of the plurality of UEs. The method according to claim 1, further comprising:

12. The method according to claim 1, further comprising transmitting a capability request for the capability information of each of the plurality of UEs to the first UE before acquiring the capability information of each of the plurality of UEs, wherein acquiring the capability information of each of the plurality of UEs is in response to the capability request.

13. A method performed in a first UE among a plurality of UEs to support sidelink positioning of a plurality of UEs, the method being: (i) Send an MO-LR request for location-related information to the location server, or (ii) Receiving MT-LR requests or periodic or triggered MT-LR requests from the location server regarding the location-related information. Performing an action that includes one of the following, To discover other UEs among the aforementioned multiple UEs, To obtain capability information for each of the aforementioned multiple UEs, Transmitting the capability information of each of the plurality of UEs to the location server, Receiving a message from the location server, wherein the message is at least partially based on the capability information of each of the plurality of UEs. Adjusting the sidelink positioning of the plurality of UEs based at least in part on the aforementioned message, Based on the side-link positioning of the aforementioned multiple UEs, location measurement values ​​or location results, or both, When the message includes a request for the location measurement or the location result, the location server shall transmit the location measurement or the location result to the location server, wherein the location server shall calculate and transmit the location result based on the location measurement when the first UE transmits the location measurement to the location server. A method comprising (ii) the first UE performing an operation which includes receiving the MT-LR request or the periodic or triggered MT-LR request, wherein the MT-LR request includes the periodic or triggered MT-LR request, the periodic or triggered MT-LR request includes a periodic event or a trigger event, the trigger event is based on a range or relative velocity of the UEs among the plurality of UEs.

14. A location server that supports sidelink positioning of multiple user devices (UEs), wherein the location server One or more transceivers, One or more memory devices, The system comprises one or more transceivers and one or more processors communicably coupled to the one or more memories, wherein the one or more processors Receiving a request for location-related information for the plurality of UEs via one or more transceivers, wherein the request is associated with a first UE among the plurality of UEs, (i) A mobile outgoing location request (MO-LR) transmitted by the first UE, (ii) Mobile incoming location requests (MT-LR) sent by an external client or periodic or triggered MT-LRs, Receiving based on one of the following, Acquiring capability information of each of the multiple UEs from the first UE among the multiple UEs via the one or more transceivers, To obtain the aforementioned location-related information, Transmitting the location-related information via one or more of the aforementioned transceivers, wherein the transmission is (i) In response to the request for location-related information being based on MO-LR, transmit the location-related information to the first UE, wherein the location-related information supports sidelink positioning of the plurality of UEs, or (ii) In response to the request for location-related information being based on MT-LR or periodic or triggered MT-LR, transmitting the location-related information to the external client, wherein the location-related information is based on the sidelink positioning of the plurality of UEs. Transmitting the location-related information, including one of the following: It is configured to do the following: The request is based on the periodic or triggered MT-LR transmitted by the external client, the periodic or triggered MT-LR includes a periodic event or a trigger event, and the trigger event is based on a range or relative velocity of UEs among a plurality of UEs, the location server.

15. A first UE among a plurality of UEs that supports sidelink positioning of a plurality of UEs, wherein the first UE is One or more transceivers, One or more memory devices, The system comprises one or more transceivers and one or more processors communicably coupled to the one or more memories, wherein the one or more processors (i) Send an MO-LR request for location-related information to the location server, or (ii) Receiving MT-LR requests or periodic or triggered MT-LR requests from the location server regarding the location-related information. Performing an action that includes one of the following, To discover other UEs among the aforementioned multiple UEs, To obtain capability information for each of the aforementioned multiple UEs, Transmitting the capability information of each of the plurality of UEs to the location server, Receiving a message from the location server, wherein the message is at least partially based on the capability information of each of the plurality of UEs. Adjusting the sidelink positioning of the plurality of UEs based at least in part on the aforementioned message, Based on the side-link positioning of the aforementioned multiple UEs, location measurement values ​​or location results, or both, When the message includes a request for the location measurement or the location result, the location server shall transmit the location measurement or the location result to the location server, wherein the location server shall calculate and transmit the location result based on the location measurement when the first UE transmits the location measurement to the location server. It is configured to do the following: The one or more processors are configured to receive the periodic or triggered MT-LR requests in order to perform an operation which includes receiving the MT-LR requests or the periodic or triggered MT-LR requests, wherein the periodic or triggered MT-LR requests include a periodic event or a trigger event, and the trigger event is a first UE based on a range or relative velocity of the UEs among the plurality of UEs.

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