Determining a subset of candidate positioning anchors

Abstract

A method is disclosed that includes receiving, by a device, assistance information associated with at least one positioning anchor of a device to be replaced or at least one positioning anchor to be added for the device; determining, by the device, a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors based on the assistance information, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; and transmitting, by the device, measurement information associated with the subset of one or more candidate positioning anchors.

Description

[Technical Field]

[0001] The following exemplary embodiments relate to wireless communications and positioning. [Background technology]

[0002] Positioning techniques may be used to estimate the location of a user device. However, positioning involves the use of network resources. Because resources are limited, it is desirable to optimize the use of network resources. Summary of the Invention

[0003] The scope of protection sought for various exemplary embodiments is set forth in the independent claims. The exemplary embodiments and features described herein that do not fall within the scope of the independent claims, if any, are to be construed as examples useful for understanding the various embodiments.

[0004] According to one aspect, an apparatus is provided that includes at least one processor and at least one memory that stores instructions that, when executed by the at least one processor, cause the apparatus to at least: receive assistance information associated with at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; determine, based on the assistance information, a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the subset of the one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; and transmit measurement information associated with the subset of the one or more candidate positioning anchors.

[0005] According to another aspect, an apparatus is provided, comprising: means for receiving assistance information associated with at least one positioning anchor of a device to be replaced or at least one positioning anchor to be added for the device; means for determining, based on the assistance information, a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; and means for transmitting measurement information associated with the subset of the one or more candidate positioning anchors.

[0006] According to another aspect, a method is provided, the method including: receiving, by a device, assistance information associated with at least one positioning anchor of a device to be replaced or at least one positioning anchor to be added for the device; determining, by the device, a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors based on the assistance information, wherein the subset of the one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; and transmitting, by the device, measurement information associated with the subset of the one or more candidate positioning anchors.

[0007] According to another aspect, a computer program product is provided that includes instructions that, when executed by an apparatus, cause the apparatus to at least: receive assistance information associated with at least one positioning anchor of the apparatus to be replaced or at least one positioning anchor to be added for the apparatus; determine, based on the assistance information, a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the subset of the one or more candidate positioning anchors satisfies at least one criterion associated with at least one positioning anchor of the apparatus to be replaced or at least one positioning anchor to be added for the apparatus; and transmit measurement information associated with the subset of the one or more candidate positioning anchors.

[0008] According to another aspect, a computer-readable medium is provided that includes program instructions that, when executed by an apparatus, cause the apparatus to at least: receive assistance information associated with at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; determine, based on the assistance information, a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the subset of the one or more candidate positioning anchors satisfies at least one criterion associated with at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; and transmit measurement information associated with the subset of the one or more candidate positioning anchors.

[0009] According to another aspect, a non-transitory computer-readable medium is provided that includes program instructions that, when executed by an apparatus, cause the apparatus to at least: receive assistance information associated with at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; determine, based on the assistance information, a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the subset of the one or more candidate positioning anchors satisfies at least one criterion associated with at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; and transmit measurement information associated with the subset of the one or more candidate positioning anchors.

[0010] According to another aspect, an apparatus is provided that includes at least one processor and at least one memory that stores instructions that, when executed by the at least one processor, cause the apparatus to at least: generate assistance information for assisting a user device to determine a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the assistance information is associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device; transmit the assistance information to the user device; and receive, from the user device, measurement information associated with the subset of one or more candidate positioning anchors, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device.

[0011] According to another aspect, an apparatus is provided, comprising: means for generating assistance information for assisting a user device to determine a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the assistance information is associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device; means for transmitting the assistance information to the user device; and means for receiving, from the user device, measurement information associated with the subset of one or more candidate positioning anchors, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device.

[0012] According to another aspect, a method is provided, the method including: generating assistance information for assisting a user device to determine a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, the assistance information being associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device; transmitting the assistance information to the user device; and receiving, from the user device, measurement information associated with the subset of one or more candidate positioning anchors, the subset of one or more candidate positioning anchors satisfying at least one criterion associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device.

[0013] According to another aspect, a computer program product is provided that includes instructions that, when executed by an apparatus, cause the apparatus to at least: generate assistance information for assisting a user device to determine a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the assistance information is associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device; transmit the assistance information to the user device; and receive, from the user device, measurement information associated with the subset of one or more candidate positioning anchors, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device.

[0014] According to another aspect, a computer-readable medium is provided that includes program instructions that, when executed by an apparatus, cause the apparatus to at least: generate assistance information for assisting a user device to determine a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the assistance information is associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device; transmit the assistance information to the user device; and receive, from the user device, measurement information associated with the subset of one or more candidate positioning anchors, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device.

[0015] According to another aspect, a non-transitory computer-readable medium is provided that includes program instructions that, when executed by an apparatus, cause the apparatus to at least: generate assistance information for assisting a user device to determine a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the assistance information is associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device; transmit the assistance information to the user device; and receive, from the user device, measurement information associated with the subset of one or more candidate positioning anchors, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device.

[0016] In the following, various exemplary embodiments will be described in more detail with reference to the accompanying drawings. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 illustrates an example of a cellular communication network. [Figure 2] FIG. 1 illustrates an example network-assisted sidelink positioning scenario. [Figure 3] FIG. 10 illustrates an example of candidate positioning anchor measurement reporting. [Figure 4] 1 is a signal transmission diagram. [Figure 5] 1 is a signal transmission diagram. [Figure 6] 1 is a flowchart. [Figure 7] 1 is a flowchart. [Figure 8] FIG. 1 illustrates an example of an apparatus. [Figure 9] FIG. 1 illustrates an example of an apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0018] The following embodiments are illustrative. Although this specification may refer to "an," "one," or "some" embodiments in several places in the text, this does not necessarily mean that each reference is to the same embodiment or that a particular feature only applies to a single embodiment. Single features of different embodiments may be combined to provide other embodiments.

[0019] In the following, different exemplary embodiments are described using radio access architectures based on Long Term Evolution Advanced (LTE-A), New Radio (NR, 5G), beyond 5G, or sixth generation (6G) as examples of access architectures to which the exemplary embodiments may be applied, without, however, limiting the exemplary embodiments to such architectures. It will be clear to those skilled in the art that the exemplary embodiments may also be applied to other types of communication networks with appropriate means by appropriately adjusting parameters and procedures. Some examples of other options for suitable systems may be a universal mobile telecommunications system (UMTS) radio access network (UTRAN or E-UTRAN), Long Term Evolution (LTE, essentially the same as E-UTRAN), a wireless local area network (WLAN or Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Bluetooth, personal communications services (PCS), ZigBee, wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, sensor networks, mobile ad-hoc networks (MANET), and Internet Protocol multimedia subsystem (IMS), or any combination thereof.

[0020] 1 shows an example of a simplified system architecture showing several elements and functional entities, all of which are logical units whose implementation may differ from that shown. The connections shown in FIG. 1 are logical connections; the actual physical connections may differ. It will be apparent to one skilled in the art that the system may have functions and structures other than those shown in FIG. 1.

[0021] The exemplary embodiment is however not limited to the system given as an example, and a person skilled in the art may apply the solution to other communication systems that have the required characteristics.

[0022] The example of FIG. 1 shows a portion of an exemplary radio access network.

[0023] FIG. 1 illustrates an access node (AN) 104, such as an evolved Node B (eNB, abbreviated as eNodeB) or next generation Node B (gNB, abbreviated as gNodeB), providing a radio cell, and user devices 100 and 102 configured to be wirelessly connected with one or more communication channels within the radio cell. The physical link from the user device to the access node may be referred to as an uplink (UL) or reverse link, and the physical link from the access node to the user device may be referred to as a downlink (DL) or forward link. A user device may communicate directly with another user device via sidelink (SL) communication. It should be appreciated that the access node or its functionality may be performed by using any node, host, server, or access point, or other entity suitable for such use.

[0024] A communication system may include two or more access nodes, in which case the access nodes may be configured to communicate with each other through links (wired or wireless) designed for that purpose. These links may be used for signal transmission and also for routing data from one access node to another. An access node may be a computing device configured to control radio resources of a communication system to which the access node is coupled. An access node may also be referred to as a base station, base transceiver station (BTS), access point, or any other type of interfacing device, including a relay station, capable of operating in a wireless environment. An access node may include or be coupled to a transceiver. From the access node's transceiver, a connection may be provided to an antenna unit that establishes a bidirectional radio link to a user device. The antenna unit may include multiple antennas or antenna elements. The access node may be further connected to a core network 110 (core network (CN) or next generation core (NGC)). Depending on the deployed technology, the access node may be connected on the CN side to a serving gateway (S-GW, routes and forwards user data packets), packet data network gateway (P-GW) for providing user device connectivity to external packet data networks, user plane function (UPF), mobility management entity (MME), or access and mobility management function (AMF), etc.

[0025] With regard to positioning, the service-based architecture (core network) may comprise an AMF 111 and a location management function (LMF) 112. The AMF may provide location information for call processing, policy, and billing to other network functions in the core network and other entities that request positioning of terminal devices. The AMF may receive and manage location requests from several sources: mobile-originated location requests (MO-LR) from user devices and mobile-terminated location requests (MT-LR) from other functions in the core network or from other network elements. The AMF may select an LMF for a given request and use its positioning service to trigger a positioning session. The LMF may then perform positioning upon receiving such a request from the AMF. The LMF may manage resources and timing of positioning activities. The LMF may use the Namf_Communication service over the NL1 interface to request positioning of the user device from one or more access nodes, or the LMF may communicate with the user device through N1 for UE-based or UE-assisted positioning. The positioning may include an estimation of the location, and the LMF may also estimate the movement or accuracy of the location information when requested. In relation to the connection, the AMF is between the access node and the LMF and may therefore be closer to the access node than the LMF.

[0026] A user device represents one type of device to which resources over the air interface may be allocated and assigned, and therefore any features described herein with respect to a user device may also be implemented using a corresponding device such as a relay node.

[0027] An example of such a relay node may be a Layer 3 relay (self-backhauling relay) for an access node. A self-backhauling relay node may also be called an integrated access and backhaul (IAB) node. An IAB node may comprise two logical parts: a mobile termination (MT) part that handles the backhaul link (i.e., the link between the IAB node and a donor node, also known as a parent node), and a distributed unit (DU) part that handles the access link (i.e., the child link between the IAB node and a user device and / or between the IAB node and other IAB nodes (multi-hop scenarios).

[0028] Another example of such a relay node may be a Layer 1 relay, called a repeater, which may amplify signals received from an access node and forward the signals to a user device and / or may amplify signals received from a user device and forward the signals to the access node.

[0029] A user device may be referred to as a subscriber unit, mobile station, remote terminal, access terminal, user terminal, terminal device, or user equipment (UE), to name a few. A user device may refer to a portable computing device, including a wireless mobile communication device operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: mobile station (mobile phone), smartphone, personal digital assistant (PDA), handset, device using a wireless modem (such as an alarm or measurement device), laptop and / or touchscreen computer, tablet, game console, notebook, multimedia device, reduced capability (RedCap) device, wireless sensor device, or any device integrated into a vehicle.

[0030] It should be appreciated that a user device may be almost exclusively an uplink-only device, an example of which may be a camera or video camera that loads images or video clips onto the network. A user device may also be a device capable of operating in an Internet of Things (IoT) network, a scenario in which objects may have the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction. A user device may utilize the cloud. In some applications, a user device may comprise a small, portable, or wearable device with wireless components (such as a watch, earphones, or glasses), and computation may be performed in the cloud or in another user device. A user device (or, in some exemplary embodiments, a Layer 3 relay node) may be configured to perform one or more of the user equipment functions.

[0031] The various techniques described herein may be applied to cyber-physical systems (CPSs)—systems of cooperating computational elements that control physical entities. CPSs may enable the execution and utilization of vast numbers of interconnected ICT devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects at different locations. Mobile cyber-physical systems, in which the physical systems in question may have inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals.

[0032] Furthermore, although the device is shown as a single entity, it may be implemented as different units, processors and / or memory units (not all shown in FIG. 1).

[0033] 5G allows for many more base stations or nodes than LTE (the so-called small cell concept), including macro sites operating in cooperation with smaller stations using multiple input-multiple output (MIMO) antennas and employing various radio technologies depending on service needs, use cases, and / or available spectrum. 5G mobile communications may support a wide range of use cases and related applications, including video streaming, augmented reality, different methods of data sharing, and various forms of machine-type applications (such as massive machine-type communication (mMTC) including vehicle safety, different sensors, and real-time control). 5G may have multiple air interfaces, i.e., sub-6 GHz, cm-wave, and mm-wave, and may also be integrated with existing legacy radio access technologies such as LTE. Integration with LTE may be implemented, for example, as a system in which macro coverage may be provided by LTE and 5G air interface access may come from small cells through aggregation to LTE. In other words, 5G may support both inter-RAT interoperability (e.g., LTE-5G) and inter-RI interoperability (interoperability between air interfaces such as sub-6 GHz-cm wave-mm wave). One concept that may be used in 5G networks may be network slicing, in which multiple independent and dedicated virtual sub-networks (network instances) may be created within substantially the same infrastructure to run services with different requirements in terms of latency, reliability, throughput, and mobility.

[0034] The current architecture in LTE networks may be fully distributed in the radio and fully centralized in the core network. Low-latency applications and services in 5G may require content to be closer to the radio, which leads to local breakout and multi-access edge computing (MEC). 5G may enable analytics and knowledge generation to occur at the source of the data. This approach may require effective utilization of resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC may provide a distributed computing environment for application and service hosting. MEC may have the ability to store and process content close to cellular subscribers for faster response times. Edge computing may cover a wide range of technologies, such as wireless sensor networks, mobile data acquisition, mobile signature analysis, collaborative distributed peer-to-peer ad hoc networking, and processing that can also be categorized as cloud / fog computing and grid / mesh computing, dew computing, mobile edge computing, cloudlets, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and / or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications).

[0035] The communications system may be able to communicate with or use services provided by one or more other networks 113, such as the public switched telephone network or the Internet. The communications network may be able to support the use of cloud services, e.g., at least part of the core network operations may be implemented as cloud services (this is illustrated in FIG. 1 by "cloud" 114). The communications system may comprise a central control entity or the like that provides facilities for networks of different operators to cooperate, e.g., in spectrum sharing.

[0036] The access node may be divided into a radio unit (RU) comprising a radio transceiver (TRX), i.e., a transmitter (Tx) and a receiver (Rx), one or more distributed units (DUs) 105 that may be used for so-called Layer 1 (L1) processing and real-time Layer 2 (L2) processing, and a central unit (CU) 108 (also known as a centralized unit) that may be used for non-real-time L2 and Layer 3 (L3) processing. The CU 108 may be connected to one or more DUs 105, for example, via an F1 interface. Such division may enable centralization of the CU with respect to the cell site and the DU, while the DU may be more decentralized and remain at the cell site. The CU and DU together may be referred to as baseband or baseband unit (BBU). The CU and DU may be included in a radio access point (RAP).

[0037] The CU 108 may be defined as a logical node that hosts higher layer protocols, such as radio resource control (RRC), service data adaptation protocol (SDAP), and / or packet data convergence protocol (PDCP), of an access node. The DU 105 may be defined as a logical node that hosts radio link control (RLC), medium access control (MAC), and / or physical (PHY) layers of an access node. The operation of the DU may be controlled at least in part by the CU. The CU may comprise a control plane (CU-CP), which may be defined as a logical node that hosts the RRC and control plane portions of the CU's PDCP protocol for the access node. The CU may further comprise a user plane (CU-UP), which may be defined as a logical node that hosts the user plane portions of the CU's PDCP and SDAP protocols for the access node.

[0038] A cloud computing platform may be used to execute the CU 108 and / or the DU 105. The CU may execute on the cloud computing platform, which may be referred to as a virtualized CU (vCU). In addition to the vCU, there may be a virtualized DU (vDU) executing on the cloud computing platform. Furthermore, a combination may exist, where the DU may use a so-called bare-metal solution, e.g., an application-specific integrated circuit (ASIC) or a customer-specific standard product (CSSP) system-on-a-chip (SoC) solution. It should also be understood that the distribution of functionality between the above-mentioned access node units or between different core network operations and access node operations may differ.

[0039] An edge cloud may be joined to a radio access network (RAN) by utilizing network function virtualization (NFV) and software defined networking (SDN). Using an edge cloud may mean that access node operations are at least partially implemented in a server, host, or node operatively coupled to a remote radio head (RRH) or radio unit (RU), or an access node comprising a radio portion. It is also possible that node operations may be distributed among multiple servers, nodes, or hosts. Application of a Cloud RAN architecture allows RAN real-time functions to be implemented on the RAN side (e.g., in the DU 105) and non-real-time functions to be implemented in a centralized manner (e.g., in the CU 108).

[0040] It should also be understood that the distribution of functions between core network operations and access node operations may differ from or even not exist in LTE. Some other technological advances that may be used include big data and all-IP, which may change the way networks are built and managed. 5G (or New Radio, NR) networks may be designed to support multiple hierarchies in which MEC servers may be located between the core and access nodes. It should be recognized that MEC may also be applied in 4G networks.

[0041] 5G may utilize non-terrestrial communications, such as satellite communications, to augment or complement 5G service coverage by providing backhauling. Possible use cases may include providing service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for passengers aboard vehicles, or ensuring service availability for critical communications and future rail, maritime, and aviation communications. Satellite communications may utilize geostationary earth orbit (GEO) satellite systems, as well as low earth orbit (LEO) satellite systems, particularly mega-constellations (systems in which hundreds of (nano)satellites are deployed). A given satellite 106 in a mega-constellation may cover several satellite-enabled network entities, creating on-ground cells. On-ground cells may be created through on-ground relay nodes or by access nodes 104 located on-ground or within the satellite.

[0042] 6G networks are expected to employ flexible decentralized and / or distributed computing systems and architectures and ubiquitous computing, with local spectrum licensing, spectrum sharing, infrastructure sharing, and intelligent automated management underpinned by mobile edge computing, artificial intelligence, short packet communications, and blockchain technologies. Key features of 6G may include intelligent connected management and control capabilities, programmability, integrated sensing and communications, reduced energy footprint, reliable infrastructure, scalability, and affordability. In addition, 6G also opens up new use cases covering the integration of location and sensing capabilities to system definitions for unifying user experiences across the physical and digital worlds.

[0043] It is apparent to those skilled in the art that the illustrated system is only a partial example of a wireless access system, and in practice, the system may include multiple access nodes, a user device may be able to access multiple wireless cells, and the system may include other devices such as physical layer relay nodes or other network elements, etc. At least one of the access nodes may be a Home eNodeB or a Home gNodeB.

[0044] Furthermore, within the geographical area of ​​the wireless communication system, multiple radio cells of different types may be provided. The radio cells may be macrocells (or umbrella cells), which may be large cells with a diameter of up to tens of kilometers, or small cells such as microcells, femtocells, or picocells. The access nodes of FIG. 1 may provide any type of these nodes. The cellular wireless system may be implemented as a multi-layer network including several types of radio cells. In a multi-layer network, one access node may provide one or more radio cells of one type, and therefore multiple access nodes may be required to provide such a network structure.

[0045] To achieve the need for improved deployment and performance of communication systems, the concept of a "plug-and-play" access node may be introduced. A network that may be able to use the "plug-and-play" access node may include a Home Node B gateway or HNB-GW (not shown in FIG. 1) in addition to a Home eNodeB or Home gNodeB. The HNB-GW, which may be installed in an operator's network, may aggregate traffic from multiple Home eNodeBs or Home gNodeBs back to the core network.

[0046] Positioning techniques may be used to estimate the position (e.g., geographic location) of a user device. Herein, a positioned user device is referred to as a target user device or target UE. For example, positioning techniques used in NR may be based on at least one of time difference of arrival (TDoA), time of arrival (TOA), time of departure (TOD), round trip time (RTT), angle of departure (AoD), angle of arrival (AoA), and / or carrier phase.

[0047] The location of the target UE may be estimated in an absolute manner (in the case of absolute positioning) or in a relative manner (in the case of relative positioning).

[0048] Absolute positioning refers to estimating the location of a target UE in two-dimensional or three-dimensional geographic coordinates (eg, latitude, longitude, and / or altitude) within a coordinate system.

[0049] Relative positioning refers to estimating the location of a target UE relative to one or more network nodes or relative to one or more other UEs.

[0050] In Uu positioning (UL / DL positioning), multiple transmission and reception points (TRPs) within known locations may transmit and / or receive one or more positioning reference signals (PRS) to / from a target UE. In the uplink, a sounding reference signal (SRS) may be used as a positioning reference signal. For example, a multilateration technique may then be used to locate (position) the target UE with respect to the TRPs. At least one of these TRPs may be used as a positioning anchor, and the difference in TDoA may be calculated with respect to this positioning anchor. A positioning anchor may also be referred to as an anchor, anchor node, multilateration anchor, or reference point.

[0051] In network-based positioning, the location of the target UE is calculated by a network node, and for network-based positioning, the target UE may report information to the network to enable the calculation.

[0052] In UE-based positioning, the location of the target UE is calculated by the target UE or another UE.

[0053] Sidelink (SL) positioning refers to a positioning approach in which a target UE utilizes a sidelink (i.e., a direct device-to-device link) to position itself in an absolute manner (for absolute positioning) or a relative manner (for relative positioning). SL positioning can be beneficial in, for example, but not limited to, the following use cases: public safety, vehicle-to-everything (V2X), and industrial internet of things (IIoT).

[0054] SL positioning may be based on the transmission of sidelink positioning reference signals (SL-PRS) by multiple anchor UEs (anchor user devices), which are received and measured by a target UE to enable location of the target UE within the specific latency and accuracy requirements of the corresponding SL positioning session (e.g., using SL TDoA techniques). Alternatively or additionally, the target UE may transmit SL-PRS that is received and measured by the anchor UE. The exchange of SL-PRS between the target UE and anchor UE may be used, for example, in SL RTT-based positioning techniques.

[0055] An anchor UE may be defined as a UE that supports positioning of a target UE, for example, by transmitting and / or receiving reference signals (e.g., SL-PRS) for positioning over the SL interface. This may be similar to UL / DL-based positioning, where the gNB may serve as a positioning anchor that transmits and / or receives reference signals to / from the target UE for positioning. Herein, the anchor UE may be referred to as a positioning anchor.

[0056] The SL PRS refers to a reference signal transmitted over the SL for positioning. The SL PRS may be configured with respect to various parameters including time-frequency resources such as bandwidth and periodicity, directivity-related parameters such as beam direction, beam width, number of beams, etc., and transmit power. Such parameters may be collectively referred to as the SL PRS (pre)configuration.

[0057] In network coverage or partial coverage scenarios, the SL PRS configuration may be determined by the network, for example by the location management function (LMF) or the gNB. In out-of-coverage scenarios, the SL PRS configuration may be (pre-)configured and / or determined autonomously by the UE.

[0058] For UE-assisted positioning (SL positioning and Uu positioning), the target UE may utilize the sidelink to obtain positioning measurements and report the measurements to a network entity such as the LMF. Sidelink positioning may be used to obtain ranging information. Ranging refers to determining the distance between two UEs and / or the direction of one UE from another UE via a direct device connection.

[0059] In network-assisted sidelink positioning, the network (e.g., LMF) is in control of the sidelink positioning. In this case, the network may perform, for example, anchor (re)selection and / or SL-PRS (pre)configuration. For network-assisted sidelink positioning, the UE may report information such as sidelink measurements to the network.

[0060] FIG. 2 illustrates an example of a network-assisted sidelink positioning scenario, in which a target UE 201 receives SL-PRSs from three anchor UEs 202, 203, and 204 to conduct a sidelink positioning session, i.e., to determine the location of the target UE 201. Here, the anchor UEs 202, 203, and 204 are said to provide SL-PRS assistance (including SL-PRS transmission) to the target UE 201. The LMF 205 may be under full or partial control of the SL positioning. The LMF 205 is responsible for at least anchor (re)selection based at least on sidelink measurement information reported from the target UE, e.g., through the LTE positioning protocol (LPP). The target UE may obtain measurement information by measuring SL-PRSs and / or anchor discovery messages received from the anchor UEs 202, 203, and 204. The measurement information may include, e.g., reference signal received power (RSRP) of the SL-PRSs and / or anchor discovery messages.

[0061] In network-assisted sidelink positioning (e.g., based on SL TDOA, SL multi-RTT, etc.), the network (e.g., LMF) may be under full or partial control of SL positioning. For example, the LMF may be responsible for anchor (re)selection based at least on measurement information reported from the target UE (e.g., through LPP). However, anchor (re)selection is not an easy task because it directly affects positioning accuracy. For example, if the selected anchor UE is collinear with the target UE, the target UE may experience high geometric dilution of precision (GDOP), and positioning accuracy may be significantly reduced. Furthermore, the radio link quality between a given anchor UE and the target UE affects the reception quality of the SL-PRS at the target UE and, therefore, the positioning accuracy. For this reason, the target UE may report information related to candidate anchor UEs, so that the LMF can perform informed anchor (re)selection to meet the accuracy requirements of the target UE. In this specification, a candidate anchor UE (candidate positioning anchor) refers to a potential anchor UE (positioning anchor) that is not yet active (e.g., does not yet transmit SL-PRS) in supporting positioning of a target UE, but has the potential to do so.

[0062] In the case of anchor discovery, a candidate anchor UE may send an anchor discovery message over the sidelink (i.e., the PC5 interface). The target UE may receive the discovery message and report corresponding measurements (including discovery information such as anchor UE location) to the LMF to assist anchor (re)selection. Currently, during anchor reselection, the target UE may report measurements of all candidate anchor UEs to the LMF. However, this may introduce a large signaling overhead over the Uu interface. The signaling overhead may be even more severe when there are frequent anchor reselections (which may occur in SL positioning due to UE mobility) and when there are a large number of candidate anchor UEs (e.g., in dense UE deployment scenarios).

[0063] 3 shows an example of candidate positioning anchor measurement reporting from the target UE 300 to the LMF 320 for anchor reselection when the active positioning anchor 301 fails to support the target UE 300 in SL positioning. Herein, candidate positioning anchor measurements may include discovery-related measurements corresponding to anchor discovery messages transmitted from a set of candidate positioning anchors 302, 303, 304, 305, 307, 308, 310, 311, 312, and 313 (e.g., candidate anchor UEs), excluding the active positioning anchors 301, 306, and 309. For the active positioning anchors, the target UE 300 may report, for example, SL-PRS-related measurements. If the target UE 300 reports discovery-related measurements for all candidate positioning anchors 302, 303, 304, 305, 307, 308, 310, 311, 312, and 313, this may introduce a large signaling overhead over the Uu interface. Therefore, there is a need to improve this suboptimal method of reporting discovery-related measurements to the LMF in terms of signaling overhead.

[0064] Some example embodiments provide a network-assisted candidate positioning anchor filtering mechanism that may be used to reduce signaling overhead over the Uu interface during anchor reselection.

[0065] Some exemplary embodiments are described below using principles and terminology of 5G technology, however, without limiting the exemplary embodiments to 5G communication systems.

[0066] In an example embodiment, upon detecting a need for a new positioning anchor for a target UE (e.g., observing that one of the currently active positioning anchors has failed or is in a non-line-of-sight condition for the target UE), the LMF may trigger candidate positioning anchor measurement reporting at the target UE and provide assistance information to the target UE for filtering candidate positioning anchors. This assistance information may be associated with at least the positioning anchor to be replaced and / or the potential new positioning anchor to be added for the target UE. The target UE may then filter the candidate positioning anchors based on the received assistance information and report only the filtered candidate positioning anchor measurements to the LMF.

[0067] In one example, the LMF may adjust the filtering so that the target UE reports measurements of only candidate positioning anchors that, if selected as a positioning anchor in place of a failed anchor, are at least likely to meet the GDOP criteria (and thus likely to meet the positioning requirements). In this way, signaling overhead in measurement reporting may be reduced because the target UE reports measurements associated with some, but not all, candidate positioning anchors. It should be noted that GDOP is used herein as just one example, and other criteria may alternatively be used to instruct the target UE on how to filter measurements.

[0068] Considering the impact of GDOP on positioning anchor (re)selection, knowledge at the target UE as to which positioning anchor will be replaced with a new positioning anchor (as part of the anchor reselection procedure) may enable the target UE to filter candidate positioning anchor measurements to reduce signaling overhead over the Uu interface.

[0069] When an active positioning anchor fails and needs to be replaced (while other active positioning anchors continue to support the target UE), suitable candidate positioning anchors to replace the failed positioning anchor may share similar geometric properties (e.g., angle relative to the target UE) as those of the failed positioning anchor. In other words, the selection of a replacement anchor may be constrained by GDOP performance. Thus, when the target UE provides discovery-related measurements of candidate positioning anchors to the LMF, the relevant measurements for the LMF in anchor reselection are those of candidate positioning anchors that share similar geometric properties as the failed positioning anchor that needs to be replaced.

[0070] Thus, signaling overhead may be reduced by having the target UE report measurements of only relevant candidate positioning anchors (instead of all discovered candidate positioning anchors), which may also make sidelink positioning more viable in scenarios with a large number of candidate positioning anchors (e.g., in IoT use cases) and / or scenarios involving mobile target UEs and / or mobile positioning anchors (e.g., in V2X use cases).

[0071] To this end, the LMF may provide the target UE with assistance information through which the LMF may convey information about the positioning anchor to be replaced, such as the identity of the failed positioning anchor and / or the geometric properties of the failed positioning anchor relative to the target UE. Using this assistance information, the target UE can then identify a (filtered) subset of candidate positioning anchors that may be of interest in anchor reselection (e.g., identify candidate positioning anchors that may ensure sufficient GDOP performance when used as positioning anchors in place of the failed positioning anchor).

[0072] Some example embodiments may be applied, for example, to the system shown in Figure 3. In this case, the target UE 300 may perform filtered candidate positioning anchor measurement reporting to the LMF 320 for anchor reselection when an active positioning anchor 301 fails to support the target UE 300 in SL positioning. Upon identifying the failed positioning anchor 301, the LMF 320 provides the target UE 300 with assistance information associated with the failed positioning anchor 301.

[0073] The assistance information may include, for example, at least one of an identifier of the failed positioning anchor 301 to be replaced (which serves as a reference based on which a new anchor will be selected), a reason for replacing the failed positioning anchor 301, and / or geometric characteristics of the failed positioning anchor 301 relative to the target UE 300.

[0074] The target UE 300 then utilizes this assistance information to identify a subset of one or more candidate positioning anchors from the discovered set of candidate positioning anchors 302, 303, 304, 305, 307, 308, 310, 311, 312, 313, where the subset of one or more candidate positioning anchors meet at least one criterion associated with the failed positioning anchor 301 to be replaced (e.g., an angle relative to the target UE 300 or a similar geographic characteristic relative to the target UE 300, such as the same geographic area / zone relative to the target UE 300 or closer to the failed positioning anchor 301). For example, the subset of one or more candidate positioning anchors may comprise candidate positioning anchors 302, 304 located in close proximity to the failed positioning anchor 301 to be replaced.

[0075] The target UE 300 then sends a filtered candidate positioning anchor measurement report to the LMF 320, which includes measurement information associated with a subset of one or more candidate positioning anchors 302, 304 (filtered candidate positioning anchors) instead of all discovered candidate positioning anchors 302, 303, 304, 305, 307, 308, 310, 311, 312, 313. Thus, signaling overhead over the Uu interface may be reduced. Herein, the measurement information reported to the LMF may include discovery-related measurements corresponding to anchor discovery messages sent from each candidate positioning anchor.

[0076] Referring to FIG. 3, in an exemplary embodiment, the LMF 320 may be configured to perform positioning anchor selection and reselection for the target UE 300, determine the need for a new positioning anchor to be added for the target UE 300 (e.g., due to failure of an existing positioning anchor 301 due to degraded reception quality of the SL PRS at the target UE 300 transmitted by the anchor 301), request candidate positioning anchor measurement reporting from the target UE 300 based at least on the determination of the need for the new positioning anchor, and prepare assistance information for candidate positioning anchor filtering based at least on the “to-be-replaced” positioning anchor and / or the potential new anchor to be added.

[0077] The assistance information for candidate positioning anchor filtering may include at least one of an identifier of the positioning anchor to be replaced, geometric characteristics of the new positioning anchor to be added and / or the positioning anchor to be replaced (e.g., angle or sector of the failed anchor UE relative to the target UE 300), one or more conditions for the positioning anchor to be added (e.g., SL PRS RSRP greater than a certain threshold), a reason for replacing the positioning anchor to be replaced (e.g., non-line-of-sight conditions, UL transmission prioritization, de-prioritization of an existing session, link failure, etc.).

[0078] The LMF320 may be further configured to send assistance information to the target UE300, receive filtered candidate positioning anchor measurement reports from the target UE300 including discovery-related measurement information associated with a filtered subset of the candidate positioning anchors (but not all of the discovered candidate positioning anchors), perform positioning anchor reselection based at least on the filtered candidate positioning anchor measurement reports, and send a positioning anchor reconfiguration to the target UE300, the positioning anchor reconfiguration indicating at least the selected positioning anchors to be added.

[0079] The target UE 300 may be configured to receive a request for candidate positioning anchor measurement reporting from the LMF 320, receive candidate positioning anchor filtering assistance information from the LMF 320, perform candidate positioning anchor discovery (which may include performing measurements on discovery messages sent by the set of discovered candidate positioning anchors 302, 303, 304, 305, 307, 308, 310, 311, 312, 313) or (in the case of Model B type discovery) perform anchor discovery based on candidate anchor filtering, filter the discovered candidate anchors based on the candidate positioning anchor filtering assistance information, prepare a filtered candidate anchor measurement report by including discovery-related measurement information associated with the filtered candidate positioning anchors (if not all of the candidate positioning anchors), send the filtered candidate positioning anchor measurement report to the LMF 320, and receive a positioning anchor reconfiguration from the LMF 320, where the positioning anchor reconfiguration indicates at least the new positioning anchors to be added, and perform SL positioning based on the positioning anchor reconfiguration.

[0080] 4 shows a signal transmission diagram according to an exemplary embodiment. Herein, it is assumed that the LMF has already selected a set of positioning anchors for the target user device (target UE), for example, based on all candidate anchor measurements (i.e., measurements of all candidate positioning anchor discovery messages received by the target user device), and the LMF has indicated the selected positioning anchors to the target user device as part of the anchor configuration. In this exemplary embodiment, it is assumed that all (candidate) positioning anchors have transmitted Model A-type anchor discovery messages. The target user device may, for example, perform SL TDoA-based positioning using the selected positioning anchors. In FIG. 4, UE-A1 denotes one of the currently active positioning anchors of the target UE.

[0081] Herein, a given positioning anchor or candidate positioning anchor may comprise, for example, an anchor UE, a network node (e.g., gNB), a road-side unit (RSU), or any other device capable of supporting positioning of a target user device, such as a UE-type or gNB-type stationary infrastructure entity supporting V2X applications.

[0082] Referring to FIG. 4, in block 401, one of the active positioning anchors (UE-A1) of the target user device transmits a reference signal, such as an SL-PRS. However, the transmission fails and is therefore not detected by the target user device (denoted as UE-T in FIG. 4). For example, the reception quality (e.g., SL-PRS RSRP) of the SL-PRS transmitted by UE-A1 may be below a certain threshold at the target user device. Therefore, the positioning anchor UE-A1 is assumed to have failed.

[0083] The target user device may correspond to the target UE 300 in FIG. 3 or the UE 100 in FIG. 1, and UE-A1 may correspond to the failed positioning anchor 301 in FIG. 3 or the UE 102 in FIG.

[0084] At block 402, the target user device reports SL-PRS measurements to the LMF. In network-based sidelink positioning, the target user device transmits its SL-PRS measurements to the LMF, which may calculate the location of the target user device based on the measurements. The LMF may correspond to the LMF 320 in FIG. 3 or the LMF 112 in FIG. 1.

[0085] Alternatively or in addition to block 402, the target user device or positioning anchor (e.g., UE-A1) may notify the LMF that it determines that a particular positioning anchor has failed for a particular positioning anchor (e.g., UE-A1). Further, to reselect a positioning anchor, the target user device may explicitly request assistance information from the LMF to assist in filtering candidate positioning anchors at the target user device.

[0086] In block 403, upon identifying a failed positioning anchor UE-A1, for example, based on a drop in SL-PRS reception quality below a certain threshold, as indicated by an SL-PRS measurement report received from the target user device, the LMF triggers anchor reselection.

[0087] At block 404, the LMF generates and transmits to the target user device assistance information associated with at least one of the at least one positioning anchor of the target user device to be replaced (e.g., UE-A1) or the at least one positioning anchor to be added for the target user device. For example, to perform anchor reselection, the LMF may transmit a request message to the target user device to request the target user device to report discovery-related measurements of candidate positioning anchors (also referred to as candidate anchor measurements). The assistance information may be included in the request message.

[0088] The assistance information may, for example, include an identifier (e.g., anchor ID) of at least one positioning anchor to be replaced. In this way, the failed positioning anchor may serve as a reference based on which a new positioning anchor may be selected.

[0089] Alternatively or additionally, the assistance information may include or indicate a reason for replacing the at least one positioning anchor to be replaced. For example, the reason may include at least one of a non-line-of-sight (NLOS) condition between the target user device and the at least one positioning anchor to be replaced, uplink transmission prioritization, deprioritization of an existing session, or a radio link failure.

[0090] Alternatively or additionally, the assistance information may include or indicate one or more geometric characteristics of positioning anchors for the target user device, the positioning anchors including at least one of at least one positioning anchor to be replaced or at least one positioning anchor to be added.

[0091] The one or more geometric characteristics of the positioning anchor may include at least one of an angle of the positioning anchor relative to a boresight direction of the target user device or a geographic area of ​​the positioning anchor relative to the target user device. The boresight direction, also known as the boresight axis, is a reference direction in an antenna system used to describe the orientation of the antenna in space.

[0092] Alternatively or additionally, the assistance information may include or indicate at least one criterion associated with at least one of the at least one positioning anchor of the target user device to be replaced or the at least one positioning anchor to be added for the target user device. For example, the at least one criterion may include at least a criterion for a signal metric, such as an RSRP of a reference signal (e.g., SL-PRS) greater than a threshold. Alternatively or additionally, the at least one criterion may include at least a threshold for geometric degradation of precision, for example, to identify candidate positioning anchors whose GDOP is less than a threshold.

[0093] Alternatively or additionally, the assistance information may include a group identifier indicating a group of positioning anchors to be added for the target user device.

[0094] At block 405, the target user device monitors discovery messages from candidate positioning anchors. The candidate positioning anchors (e.g., UE-A2, UE-A3) are assumed to be transmitting anchor discovery messages (e.g., periodically), i.e., Model A type anchor discovery is assumed.

[0095] For Model A discovery, each UE capable of positioning anchor functionality is considered to be transmitting a discovery message (which may include their location information). When a target user device detects those discovery messages (e.g., an RSRP in the discovery message greater than a certain threshold), it identifies that a UE capable of positioning anchor functionality is nearby. Such identified UEs may be referred to as candidate positioning anchors because they have the potential to be positioning anchors for the target user device.

[0096] At block 406, the target user device receives a first discovery message from a first candidate positioning anchor (UE-A2). The first discovery message may include, for example, location information of the first candidate positioning anchor. The location information indicates the location of the first candidate positioning anchor.

[0097] At block 407, the target user device receives a second discovery message from a second candidate positioning anchor (UE-A3). The second discovery message may include, for example, location information of the second candidate positioning anchor. The location information indicates the location of the second candidate positioning anchor.

[0098] Although two candidate positioning anchors (UE-A2 and UE-A3) are shown in Figure 4, it should be noted that the number of candidate positioning anchors may be different from two. In other words, there may be one or more candidate positioning anchors. Furthermore, the signal transmission procedure shown in Figure 4 may be extended and applied according to the actual number of candidate positioning anchors.

[0099] At block 408, the target user device obtains measurement information associated with the set of one or more discovered candidate positioning anchors by measuring one or more signals, e.g., discovery messages, received from the set of one or more discovered candidate positioning anchors. For example, the measurement information may include the RSRP of the one or more signals (e.g., discovery messages).

[0100] The set of one or more discovered candidate positioning anchors refers to candidate positioning anchors from which the target user device has received a discovery message. For example, the set of one or more discovered candidate positioning anchors may include at least a first candidate positioning anchor (UE-A2) and a second candidate positioning anchor (UE-A3).

[0101] At block 409, the target user device determines, based on the assistance information, a subset of one or more candidate positioning anchors from the set of one or more discovered candidate positioning anchors, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the target user device to be replaced or the at least one positioning anchor to be added for the target user device.

[0102] The determination of the subset may also be based on location information (e.g., included in the discovery message) of a set of one or more discovered candidate positioning anchors, i.e., the subset of one or more candidate positioning anchors may be determined based at least on location information and assistance information.

[0103] The subset of one or more candidate positioning anchors may include some but not all of the set of one or more discovered candidate positioning anchors, for example, the subset of one or more candidate positioning anchors may include the first candidate positioning anchor or the second candidate positioning anchor.

[0104] As an example, if the assistance information includes an identifier (e.g., anchor ID) of at least one positioning anchor to be replaced (e.g., UE-A1), the target user device may determine a subset of one or more candidate positioning anchors by identifying one or more candidate positioning anchors that are within a certain distance (e.g., in close proximity) of the at least one positioning anchor to be replaced. To this end, the target user device may utilize a geographic area associated with the identifier (anchor ID), for example, by a zone ID, to determine the proximity of the candidate positioning anchors to the at least one positioning anchor to be replaced.

[0105] As another example, if the assistance information indicates a geographic area (e.g., a zone ID) of at least one positioning anchor to be replaced, the target user device may determine a subset of one or more candidate positioning anchors, for example, by identifying one or more candidate positioning anchors that are within the same area / zone or an adjacent area / zone to the at least one positioning anchor to be replaced.

[0106] As another example, if the assistance information indicates a reason for replacing at least one positioning anchor to be replaced, and the reason is uplink transmission prioritization or deprioritization of the current SL positioning session, the target user device may (similar to the above example) determine a subset of one or more candidate positioning anchors by identifying one or more candidate positioning anchors that are in close proximity to the at least one positioning anchor to be replaced. On the other hand, if the reason for the replacement is an NLOS condition between the target user device and the at least one positioning anchor to be replaced, the target user device may avoid candidate positioning anchors that are in close proximity to the at least one positioning anchor to be replaced.

[0107] As another example, if the assistance information includes or indicates a criterion for a signal metric, such as an RSRP of a reference signal that is greater than a threshold, the target user device may determine a subset of one or more candidate positioning anchors by identifying one or more candidate positioning anchors from which the target user device received signals, such as SL-PRS or discovery messages, with a measured signal metric, such as an RSRP greater than a threshold that may be indicated in the assistance information.

[0108] As another example, if the assistance information indicates a group identifier for a group of positioning anchors to be used for positioning, the target user device may determine a subset of one or more candidate positioning anchors by identifying one or more candidate positioning anchors that correspond to characteristics associated with the group. This group may be determined by the LMF or another core network entity based on various characteristics of the anchors. For example, mobile UEs may be in group #1, static UEs with known locations may be in group #2, static UEs with unknown locations may be in group #3, etc.

[0109] At block 410, the target user device filters measurement information associated with the set of one or more discovered candidate positioning anchors based on the assistance information. That is, the target user device retains measurements associated with only a subset of the one or more candidate positioning anchors (referred to as filtered candidate positioning anchors) that it has determined based on the assistance information received from the LMF. In other words, the measurement information may be filtered to avoid including measurement information associated with candidate positioning anchors other than the determined subset of the one or more candidate positioning anchors.

[0110] For example, the filtered measurement information associated with a subset of one or more candidate positioning anchors may be obtained by selecting a subset of measurement information from measurement information associated with a set of one or more discovered candidate positioning anchors, where the subset of measurement information corresponds to the subset of one or more candidate positioning anchors.

[0111] At block 411, the target user device transmits filtered measurement information associated with a subset of one or more candidate positioning anchors to the LMF, i.e., the target user device reports measurements associated with only a subset of one or more candidate positioning anchors, but not all of the discovered candidate positioning anchors, thus reducing signaling overhead.

[0112] At block 412, the LMF selects one or more positioning anchors from the subset of one or more candidate positioning anchors used to support positioning of the target user device based at least on the filtered measurement information. In other words, the LMF performs anchor reselection based on the received filtered measurement reports, for example, to ensure low GDOP and therefore high positioning accuracy.

[0113] In block 413, the LMF sends a message to the target user device indicating the selected positioning anchor or anchors to be used to support positioning of the target user device. For example, upon selecting a new positioning anchor, the LMF may notify the target user device about the change by sending an anchor reconfiguration message to the target user device. This allows the target user device to start using the newly selected positioning anchor to continue acquiring SL positioning support (e.g., SL-PRS) for its positioning.

[0114] FIG. 5 illustrates a signaling diagram according to an exemplary embodiment.

[0115] 5, in block 501, one of the active positioning anchors (UE-A1) of a target user device (UE-T) transmits a reference signal, such as an SL-PRS. However, the transmission fails and is therefore not detected by the target user device (denoted as UE-T in FIG. 5). For example, the reception quality (e.g., SL-PRS RSRP) of the SL-PRS transmitted by UE-A1 may be below a certain threshold at the target user device. Therefore, the positioning anchor UE-A1 is assumed to have failed.

[0116] The target user device may correspond to the target UE 300 in FIG. 3 or the UE 100 in FIG. 1, and UE-A1 may correspond to the failed positioning anchor 301 in FIG. 3 or the UE 102 in FIG.

[0117] At block 502, the target user device reports SL-PRS measurements to the LMF. In network-based sidelink positioning, the target user device transmits its SL-PRS measurements to the LMF, which may calculate the location of the target user device based on the measurements. The LMF may correspond to the LMF 320 in FIG. 3 or the LMF 112 in FIG. 1.

[0118] Alternatively or in addition to block 502, the target user device or positioning anchor (e.g., UE-A1) may notify the LMF that it determines that a particular positioning anchor has failed for a particular positioning anchor (e.g., UE-A1). Further, to reselect a positioning anchor, the target user device may explicitly request assistance information from the LMF to assist in filtering candidate positioning anchors at the target user device.

[0119] In block 503, upon identifying a failed positioning anchor UE-A1, for example, based on a drop in SL-PRS reception quality below a certain threshold, as indicated by an SL-PRS measurement report received from the target user device, the LMF triggers anchor reselection.

[0120] At block 504, the LMF generates and transmits to the target user device assistance information associated with at least one positioning anchor of the target user device to be replaced (e.g., UE-A1) or at least one positioning anchor to be added for the target user device. For example, to perform anchor reselection, the LMF may transmit a request message to the target user device to request the target user device to report discovery-related measurements of candidate positioning anchors (also referred to as candidate anchor measurements). The assistance information may be included in the request message.

[0121] The assistance information may include or indicate at least one criterion associated with at least one of the at least one positioning anchor of the target user device to be replaced or the at least one positioning anchor to be added for the target user device.

[0122] For example, the assistance information may include at least a criterion for a signal metric, such as RSRP, for at least one positioning anchor to be replaced. In this case, the target user device may use Model B type discovery and communicate the criterion to the candidate positioning anchors, for example, in a discovery solicitation message. Only candidate positioning anchors that meet the criterion then respond to the target user device and are considered to be a filtered subset of the candidate positioning anchors. For example, the candidate positioning anchors may measure the SL-PRS RSRP for at least one positioning anchor to be replaced, and if the RSRP is greater than a certain indicated threshold (suggesting that the candidate anchor is in close proximity to the anchor to be replaced), the candidate positioning anchor responds to the discovery solicitation message.

[0123] At block 505, the target user device transmits information including criteria for signal metrics to a set of one or more candidate positioning anchors. The information may be transmitted, for example, by broadcast, unicast, or multicast transmission. For example, the information may be transmitted in an anchor discovery request message.

[0124] At block 506, the positioning anchor to be replaced (UE-A1) transmits a reference signal, eg, SL-PRS, which is received by one or more candidate positioning anchors (eg, UE-A2 and UE-A3).

[0125] In block 507, the first candidate positioning anchor (UE-A2) evaluates whether the first candidate positioning anchor meets criteria for signal metrics based on the reference signal received from the positioning anchor to be replaced. In this example, the first candidate positioning anchor meets at least one criterion (e.g., the RSRP of the reference signal is greater than a threshold).

[0126] At block 508, the second candidate positioning anchor (UE-A3) evaluates whether the second candidate positioning anchor meets a criterion for signal metrics based on the reference signal received from the positioning anchor to be replaced. In this example, the second candidate positioning anchor does not meet the criterion (e.g., the RSRP of the reference signal is less than a threshold).

[0127] Although two candidate positioning anchors (UE-A2 and UE-A3) are shown in Figure 5, it should be noted that the number of candidate positioning anchors may be different from two. In other words, there may be one or more candidate positioning anchors. Furthermore, the signal transmission procedure shown in Figure 5 may be extended and applied according to the actual number of candidate positioning anchors.

[0128] At block 509, the target user device monitors for discovery messages from candidate positioning anchors.

[0129] At block 510, the target user device receives one or more signals, e.g., one or more discovery messages, from a subset of one or more candidate positioning anchors, the one or more signals being transmitted from the subset of one or more candidate positioning anchors based on the subset of one or more candidate positioning anchors satisfying criteria for signal metrics. The one or more discovery messages may include, for example, location information for the subset of one or more candidate positioning anchors.

[0130] For example, a first candidate positioning anchor (UE-A2) may transmit a signal (e.g., a discovery message) to a target user device based on the first candidate positioning anchor meeting a criterion for a signal metric, whereas a second candidate positioning anchor (UE-A3) may not transmit a signal (e.g., a discovery message) if the second candidate positioning anchor does not meet the criterion for a signal metric.

[0131] At block 511, the target user device determines a subset of one or more candidate positioning anchors (e.g., UE-A2) from the set of one or more candidate positioning anchors (e.g., UE-A2 and UE-A3), where the subset of one or more candidate positioning anchors meets a criterion for signal metrics. In this exemplary embodiment, the subset of one or more candidate positioning anchors may be determined by including some or all of the discovered candidate positioning anchors from which the target user device received a discovery message because those candidate positioning anchors meet the criterion for signal metrics.

[0132] At block 512, the target user device obtains measurement information associated with the subset of one or more candidate positioning anchors by measuring one or more signals (e.g., discovery messages) received from the subset of one or more candidate positioning anchors. For example, the measurement information may include RSRPs of the one or more signals (e.g., discovery messages).

[0133] At block 513, the target user device transmits measurement information associated with a subset of one or more candidate positioning anchors to the LMF.

[0134] At block 514, the LMF selects, based at least on the measurement information, one or more positioning anchors from the subset of one or more candidate positioning anchors used to support positioning of the target user device. In other words, the LMF performs anchor reselection based on the received and filtered measurement reports, for example, to ensure low GDOP and therefore high positioning accuracy.

[0135] At block 515, the LMF sends a message to the target user device indicating the selected positioning anchor or anchors to be used to support positioning of the target user device. For example, upon selecting a new positioning anchor, the LMF may notify the target user device about the change by sending an anchor reconfiguration message to the target user device. This allows the target user device to begin using the newly selected positioning anchor to continue to acquire SL positioning support (e.g., SL-PRS) for its positioning.

[0136] 6 shows a flowchart according to an exemplary embodiment of a method implemented by an apparatus. For example, the apparatus may be, comprise, or be included in a user device. The user device may also be referred to as a subscriber unit, mobile station, remote terminal, access terminal, user terminal, terminal device, or user equipment (UE). The user device may correspond to the user device 100, 102 of FIG. 1 or the target UE 300 of FIG. 3.

[0137] Referring to FIG. 6, at block 601, aiding information is received, the aiding information being associated with at least one positioning anchor of a device to be replaced or at least one positioning anchor to be added for the device.

[0138] At block 602, based on the assistance information, a subset of one or more candidate positioning anchors is determined from the set of one or more discovered candidate positioning anchors, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the device to be replaced or the at least one positioning anchor to be added for the device.

[0139] At block 603, measurement information associated with a subset of one or more candidate positioning anchors is transmitted.

[0140] 7 shows a flowchart according to an exemplary embodiment of a method performed by an apparatus, which may correspond to, for example, the core network 110 or the LMF 112 of FIG. 1 or the LMF 320 of FIG.

[0141] Referring to FIG. 7, in block 701, assistance information is generated to assist a user device in determining a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, the assistance information being associated with at least one of at least one positioning anchor of the user device to be replaced or at least one positioning anchor to be added for the user device.

[0142] At block 702, the assistance information is transmitted to the user device.

[0143] At block 703, measurement information is received from the user device, the measurement information being associated with a subset of one or more candidate positioning anchors, the subset of one or more candidate positioning anchors satisfying at least one criterion associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device.

[0144] The blocks, associated functions, and information exchanges (messages) described above with reference to Figures 4-7 are not in absolute chronological order, and some of them may be performed simultaneously or in a different order than described. Other functions may be performed between or among them as well, other information may be sent, and / or other rules may apply. Some of the blocks, or portions of the blocks, or one or more pieces of information may also be omitted or replaced by a corresponding block, portion of the block, or one or more pieces of information.

[0145] As used herein, "at least one of the following: <list of two or more elements>" )" and "at least one of <list of two or more elements>" )" and similar phrases where a list of two or more elements is joined by "and" or "or" mean at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0146] 8 illustrates an example of an apparatus 800 comprising means for implementing one or more of the exemplary embodiments described above. For example, the apparatus 800 may be an apparatus such as, comprising, or included in a user device. The user device may correspond to one of the user devices 100, 102 of FIG. 1, or the target UE 300 of FIG. 3, or the UE-T of FIG. 4 or 5. The user device may also be referred to as a subscriber unit, a mobile station, a remote terminal, an access terminal, a user terminal, a terminal device, or user equipment (UE).

[0147] The device 800 may comprise circuitry or a chipset applicable to implementing one or more of the exemplary embodiments described above. For example, the device 800 may comprise at least one processor 810. The at least one processor 810 interprets instructions (e.g., computer program instructions) and processes data. The at least one processor 810 may comprise one or more programmable processors. The at least one processor 810 may comprise programmable hardware with embedded firmware, or alternatively or additionally, may comprise one or more application-specific integrated circuits (ASICs).

[0148] The at least one processor 810 is coupled to the at least one memory 820. The at least one processor is configured to write / read data to / from the at least one memory 820. The at least one memory 820 may comprise one or more memory units. The memory units may be volatile or nonvolatile. It is noted that there may be one or more memory units of nonvolatile memory and one or more memory units of volatile memory, or alternatively, one or more memory units of nonvolatile memory, or alternatively, one or more memory units of volatile memory. The volatile memory may be, for example, random access memory (RAM), dynamic random access memory (DRAM), or synchronous dynamic random access memory (SDRAM). The nonvolatile memory may be, for example, read-only memory (ROM), programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), flash memory, optical storage, or magnetic storage. In general, memory may be referred to as a non-transitory computer-readable medium. The term "non-transitory," as used herein, refers to a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation regarding data storage persistence (e.g., RAM vs. ROM). At least one memory 820 stores computer-readable instructions, which are executed by at least one processor 810 to implement one or more of the exemplary embodiments described above. For example, a non-volatile memory stores the computer-readable instructions, and the at least one processor 810 executes the instructions using a volatile memory for temporary storage of data and / or instructions. The computer-readable instructions may also be referred to as computer program code.

[0149] The computer-readable instructions may be pre-stored in at least one memory 820, or alternatively or additionally, the computer-readable instructions may be received by the apparatus via an electromagnetic carrier signal and / or copied from a physical entity such as a computer program product. Execution of the computer-readable instructions by the at least one processor 810 causes the apparatus 800 to implement one or more of the exemplary embodiments described above. That is, the at least one processor and at least one memory storing instructions may provide a means for providing or effecting the performance of any of the methods and / or blocks described above.

[0150] In the context of this document, "memory" or "computer-readable media" or "computer-readable medium" may be any non-transitory medium or vehicle or means that can contain, store, communicate, propagate, or transport instructions for use by or in connection with an instruction execution system, apparatus, or device such as a computer. The term "non-transitory," as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation regarding data storage persistence (e.g., RAM vs. ROM).

[0151] The device 800 may further include or be connected to an input unit 830. The input unit 830 may include one or more interfaces for receiving input. The one or more interfaces may include, for example, one or more temperature, motion, and / or orientation sensors, one or more cameras, one or more accelerometers, one or more microphones, one or more buttons, and / or one or more touch detection units. Furthermore, the input unit 830 may include an interface to which external devices may connect.

[0152] The device 800 may comprise an output unit 840. The output unit may comprise or be connected to one or more displays capable of rendering visual content, such as a light emitting diode (LED) display, a liquid crystal display (LCD), and / or a liquid crystal on silicon (LCoS) display. The output unit 840 may further comprise one or more audio outputs. The one or more audio outputs may be, for example, loudspeakers.

[0153] The device 800 further comprises a connectivity unit 850. The connectivity unit 850 enables wireless connectivity to one or more external devices. The connectivity unit 850 comprises at least one transmitter and at least one receiver, which may be integrated into the device 800 or to which the device 800 may be connected. The at least one transmitter comprises at least one transmitting antenna, and the at least one receiver comprises at least one receiving antenna. The connectivity unit 850 may comprise an integrated circuit or a set of integrated circuits that provide wireless communication capabilities for the device 800. Alternatively, the wireless connectivity may be a hardwired application-specific integrated circuit (ASIC). The connectivity unit 850 may provide means for implementing at least some of the blocks of one or more exemplary embodiments described above. The connectivity unit 850 may include one or more components, such as a power amplifier, a digital front end (DFE), an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), a frequency converter, a (de)modulator, and / or encoder / decoder circuitry, controlled by a corresponding control unit.

[0154] It is noted that the apparatus 800 may further comprise various components not shown in Figure 8. The various components may be hardware components and / or software components.

[0155] 9 illustrates an example of an apparatus 900 comprising means for implementing one or more of the exemplary embodiments described above. For example, the means may be provided by a Location Management Function (LMF) of a core network. The apparatus 900 may correspond to the core network 110 or the LMF 112 of FIG. 1, the LMF 320 of FIG. 3, or the LMF of FIG. 4 or FIG. 5.

[0156] The apparatus 900 may include, for example, circuitry or a chipset applicable to implementing one or more of the exemplary embodiments described above. The apparatus 900 may be an electronic device including one or more electronic circuitry. The apparatus 900 may include communication control circuitry 910, such as at least one processor, and at least one memory 920 storing instructions 922, which, when executed by the at least one processor, cause the apparatus 900 to implement one or more of the exemplary embodiments described above. Such instructions 922 may include, for example, computer program code (software), and the at least one memory and the computer program code (software) are configured to, with the at least one processor, cause the apparatus 900 to implement one or more of the exemplary embodiments described above. The at least one processor and the at least one memory storing instructions may provide means for providing or effecting performance of any of the methods and / or blocks described above.

[0157] The processor is coupled to the memory 920. The processor is configured to write / read data to / from the memory 920. The memory 920 may comprise one or more memory units. The memory units may be volatile or nonvolatile. It is noted that there may be one or more units of nonvolatile memory and one or more units of volatile memory, or alternatively, one or more units of nonvolatile memory, or alternatively, one or more units of volatile memory. The volatile memory may be, for example, random access memory (RAM), dynamic random access memory (DRAM), or synchronous dynamic random access memory (SDRAM). The nonvolatile memory may be, for example, read-only memory (ROM), programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), flash memory, optical storage, or magnetic storage. In general, memory may be referred to as a non-transitory computer-readable medium. The term "non-transitory," as used herein, refers to the medium itself (i.e., tangible, not signal) as opposed to the data storage persistence (e.g., RAM vs. ROM). The memory 920 stores computer-readable instructions that are executed by the processor. For example, non-volatile memory stores the computer-readable instructions, and the processor executes the instructions using volatile memory for temporary storage of data and / or instructions.

[0158] The computer-readable instructions may be pre-stored in memory 920, or alternatively or additionally, the computer-readable instructions may be received by the device via an electromagnetic carrier signal and / or copied from a physical entity such as a computer program product. Execution of the computer-readable instructions causes the device 900 to perform one or more of the functions described above.

[0159] The memory 920 may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. The memory may include a configuration database for storing configuration data. For example, the configuration database may store a current neighbor cell list and, in some exemplary embodiments, the frame structure used in detected neighbor cells.

[0160] The device 900 may further comprise a communication interface 930 comprising hardware and / or software for achieving communication connectivity according to one or more communication protocols. The communication interface 930 may comprise at least one transmitter (Tx) and at least one receiver (Rx), which may be integrated into the device 900 or to which the device 900 may be connected. The communication interface 930 may provide means for implementing some of the blocks of one or more exemplary embodiments described above. The communication interface 930 may comprise one or more components, such as a power amplifier, a digital front end (DFE), an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), a frequency converter, a (de)modulator, and / or encoder / decoder circuitry, controlled by a corresponding control unit.

[0161] The communication interface 930 provides the device with the communication capabilities to communicate in a cellular communication system. The communication interface may provide, for example, a wireless, cable, or fiber interface to one or more network nodes of a radio access network and / or one or more user devices.

[0162] It is noted that the apparatus 900 may further comprise various components not shown in Figure 9. The various components may be hardware components and / or software components.

[0163] As used in this application, the term "circuitry" may refer to one or more or all of the following: a) hardware-only circuit implementations (such as implementations with only analog and / or digital circuitry), and b) combinations of hardware circuitry and software, for example, (where applicable): i) combinations of analog hardware circuitry and / or digital hardware circuitry with software / firmware, and ii) any portion of a hardware processor with software (including digital signal processors, software, and memory that work together to cause a device such as a mobile phone to perform various functions), and c) hardware circuitry and / or processors, such as a microprocessor or portion of a microprocessor, that require software (e.g., firmware) to operate, but the software may be absent when not required for operation.

[0164] This definition of circuitry applies to all uses of the term in this application, including in any claim. As a further example, as used in this application, the term circuitry also covers merely a hardware circuit or processor (or processors), or certain portions of a hardware circuit or processor and its (or their) associated software and / or firmware implementations. The term circuitry also covers, for example, a baseband integrated circuit, or a processor integrated circuit for a mobile device, or similar integrated circuit in a server, cellular network device, or other computing or network device, if applicable to particular claim elements.

[0165] The techniques and methods described herein may be implemented by various means. For example, these techniques may be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. In a hardware implementation, the apparatus of the exemplary embodiments may be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), graphics processing units (GPUs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. In a firmware or software implementation, the implementation may be implemented through modules (e.g., procedures, functions, etc.) of at least one chipset that perform the functions described herein. Software code may be stored in a memory unit and executed by a processor. The memory unit may execute within the processor or external to the processor. In the latter case, the memory unit may be communicatively coupled to the processor by various means, as is known in the art. Furthermore, the components of the systems described herein may be rearranged and / or supplemented by additional components to facilitate accomplishing various aspects, etc., described with respect to the components, and the components are not limited to the precise configurations set forth in the given figures, as will be recognized by those skilled in the art.

[0166] It will be obvious to those skilled in the art that as technology advances, the concept of the present invention may be implemented in various ways. The embodiments are not limited to the exemplary embodiments described above, but may vary within the scope of the claims. Therefore, all words and expressions should be interpreted broadly and are intended to illustrate, not limit, exemplary embodiments.

Claims

1. 1. An apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least: receiving assistance information associated with at least one of at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; determining a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors based on the assistance information, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the device to be replaced or the at least one positioning anchor to be added for the device; transmitting measurement information associated with said subset of one or more candidate positioning anchors; A device that performs the following.

2. The apparatus of claim 1 , wherein the transmitted measurement information does not include measurement information associated with candidate positioning anchors other than the determined subset of one or more candidate positioning anchors.

3. The device according to claim 1 or 2, wherein the at least one criterion is indicated by or included in the aiding information.

4. The apparatus of any one of claims 1 to 3, wherein said assistance information comprises an identifier of said at least one positioning anchor to be replaced.

5. The apparatus of any one of claims 1 to 4, wherein said assistance information includes or indicates a reason for replacing said at least one positioning anchor to be replaced.

6. 6. The device of claim 1, wherein the assistance information includes or indicates one or more geometric characteristics of positioning anchors for the device, the positioning anchors including at least one of the at least one positioning anchor to be replaced or the at least one positioning anchor to be added.

7. 7. The device of claim 6, wherein the one or more geometric characteristics of the positioning anchor include at least one of an angle of the positioning anchor relative to a boresight direction of the device or a geographic area of ​​the positioning anchor relative to the device.

8. 8. The apparatus of claim 1, further comprising: receiving location information of the set of one or more discovered candidate positioning anchors from the set of one or more discovered candidate positioning anchors; and determining the subset of one or more candidate positioning anchors based at least on the location information and the assistance information.

9. measurement information associated with the set of one or more discovered candidate positioning anchors is further obtained by measuring one or more signals received from the set of one or more discovered candidate positioning anchors; 9. The apparatus of claim 1, wherein the transmitted measurement information associated with the subset of one or more candidate positioning anchors is obtained by selecting a subset of measurement information from the measurement information associated with the set of one or more discovered candidate positioning anchors, the subset of measurement information corresponding to the subset of one or more candidate positioning anchors.

10. The device according to any one of claims 1 to 9, wherein the at least one criterion comprises at least a criterion for a signal metric of a reference signal.

11. transmitting information including at least the criteria for the signal metrics to the set of one or more discovered candidate positioning anchors; receiving one or more signals from the subset of one or more candidate positioning anchors, the one or more signals being transmitted from the subset of one or more candidate positioning anchors based on the subset of one or more candidate positioning anchors satisfying the criteria for the signal metric; Further work was carried out, 11. The apparatus of claim 10, wherein the measurement information associated with the subset of one or more candidate positioning anchors is obtained by measuring the one or more signals received from the subset of one or more candidate positioning anchors.

12. The apparatus of any one of claims 1 to 11, wherein said at least one criterion comprises at least a threshold value for geometric precision degradation.

13. The device of any preceding claim, wherein the assistance information comprises a group identifier indicating a group of positioning anchors attached for the device.

14. 1. An apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least: generating assistance information for assisting a user device to determine a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, the assistance information being associated with at least one of at least one positioning anchor of the user device to be replaced or at least one positioning anchor to be added for the user device; transmitting the assistance information to the user device; receiving, from the user device, measurement information associated with the subset of one or more candidate positioning anchors, the subset of one or more candidate positioning anchors satisfying at least one criterion associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device; A device that performs the following.

15. selecting one or more positioning anchors from the subset of one or more candidate positioning anchors based at least on the measurement information; sending a message to the user device indicating the selected one or more positioning anchors to be used to support positioning of the user device; The apparatus of claim 14 further comprising:

16. The apparatus of claim 14 or 15, wherein the received measurement information does not include measurement information associated with candidate positioning anchors other than the subset of one or more candidate positioning anchors.

17. 17. The apparatus of claim 14, wherein the assistance information comprises at least one of an identifier of the at least one positioning anchor to be replaced or a reason for replacing the at least one positioning anchor to be replaced.

18. 18. The apparatus of claim 14, wherein the assistance information includes or indicates one or more geometric characteristics of positioning anchors for the user device, the positioning anchors including at least one of the at least one positioning anchor to be replaced or the at least one positioning anchor to be added.

19. 20. The apparatus of claim 18, wherein the one or more geometric characteristics of the positioning anchor include at least one of an angle of the positioning anchor relative to a boresight direction of the user device or a geographic area of ​​the positioning anchor relative to the user device.

20. The device according to any one of claims 14 to 19, wherein the at least one criterion comprises at least a criterion for a signal metric of a reference signal.

21. The apparatus of any one of claims 14 to 20, wherein the at least one criterion includes at least a threshold value for geometric precision degradation.

22. The apparatus of any one of claims 14 to 21, wherein the assistance information includes a group identifier indicating a group of positioning anchors to be added for the user device.

23. receiving, by a device, assistance information associated with at least one of at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; determining, by the device based on the assistance information, a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the device to be replaced or the at least one positioning anchor to be added for the device; transmitting, by the device, measurement information associated with the subset of one or more candidate positioning anchors; A method comprising:

24. generating assistance information for assisting a user device to determine a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, the assistance information being associated with at least one of at least one positioning anchor of the user device to be replaced or at least one positioning anchor to be added for the user device; transmitting the assistance information to the user device; receiving, from the user device, measurement information associated with the subset of one or more candidate positioning anchors, the subset of one or more candidate positioning anchors satisfying at least one criterion associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device; A method comprising:

25. A non-transitory computer-readable medium containing program instructions that, when executed by an apparatus, cause the apparatus to perform at least: receiving assistance information associated with at least one of at least one positioning anchor of the device to be replaced or at least one positioning anchor to be added for the device; determining a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors based on the assistance information, wherein the subset of one or more candidate positioning anchors satisfies at least one criterion associated with at least one of the at least one positioning anchor of the device to be replaced or the at least one positioning anchor to be added for the device; transmitting measurement information associated with said subset of one or more candidate positioning anchors; A non-transitory computer-readable medium for implementing the above.

26. A non-transitory computer-readable medium containing program instructions that, when executed by an apparatus, cause the apparatus to perform at least: generating assistance information for assisting a user device to determine a subset of one or more candidate positioning anchors from a set of one or more discovered candidate positioning anchors, the assistance information being associated with at least one of at least one positioning anchor of the user device to be replaced or at least one positioning anchor to be added for the user device; transmitting the assistance information to the user device; receiving, from the user device, measurement information associated with the subset of one or more candidate positioning anchors, the subset of one or more candidate positioning anchors satisfying at least one criterion associated with at least one of the at least one positioning anchor of the user device to be replaced or the at least one positioning anchor to be added for the user device; A non-transitory computer-readable medium for implementing the above.

Images