WO2024082484A1

WO2024082484A1 - Method and apparatus of supporting positioning method selection

Info

Publication number: WO2024082484A1
Application number: PCT/CN2023/074432
Authority: WO
Inventors: Lihua Yang; Jie Hu; Jing HAN; Luning Liu; Haiming Wang
Original assignee: Lenovo (Beijing) Limited
Priority date: 2023-02-03
Filing date: 2023-02-03
Publication date: 2024-04-25

Abstract

Embodiments of the present application relate to a method and apparatus of supporting positioning method selection. An exemplary method includes: receiving, from an LMF, a first request message associated with selecting a second positioning method to replace a first positioning method; and transmitting, to the LMF, a first response message for the LMF to select the second positioning method.

Description

METHOD AND APPARATUS OF SUPPORTING POSITIONING METHOD SELECTION

TECHNICAL FIELD

Embodiments of the present application are related to wireless communication technology, especially, related to positioning techniques for wireless communication, e.g., a method and apparatus of supporting positioning method selection.

BACKGROUND OF THE INVENTION

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, and so on. Wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power) . Examples of wireless communication systems may include fourth generation (4G) systems such as long term evolution (LTE) systems, LTE-advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may also be referred to as new radio (NR) systems. However, wireless communication system still needs to evolve to pursue better service quality, better service experience and lower cost.

For example, positioning integrity concepts were introduced to support global navigation satellite system (GNSS) positioning in 3rd generation partnership project (3GPP) release (Rel) -17, which is also referred to as radio access technology (RAT) independent positioning. Regarding positioning integrity, it is defined as a measure of the trust in the accuracy of the position-related data provided by a positioning system and as the ability to provide timely and valid warnings to location service (LCS) clients when the positioning system does not fulfil the condition for intended operations. In Rel-18, researches on positioning integrity will focus on RAT-dependent positioning techniques. However, different from GNSS positioning method, RAT dependent positioning techniques involve both user equipment (UE) , next generation radio access network (NG-RAN) node (e.g., transmit-receive point (TRP) and 5G Node-B (gNB) , etc. ) and location management function (LMF) entities. Thus, error sources or feared events caused by UE moving or environment changing may affect the positioning performance. Thus, although RAT-dependent positioning will reuse some concepts and principles developed for GNSS positioning where possible, a mass of technical problems still need to be solved for RAT-dependent positioning techniques to support reliable positioning, which include but not limited to positioning method selection (or reselection) .

SUMMARY

An objective of the embodiments of the present application is to provide a technical solution for wireless communication, especially a technical solution of supporting positioning method selection, e.g., how to trigger and transfer signaling for a positioning method reselection procedure to improve the integrity of RAT-dependent positioning.

Some embodiments of the present application provide an exemplary UE, which includes: a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to: receive, from an LMF, a first request message associated with selecting a second positioning method to replace a first positioning method; and transmit, to the LMF, a first response message for the LMF to select the second positioning method.

Some other embodiments of the present application provide an exemplary method of supporting positioning method selection, which can be performed in a UE. The exemplary method includes: receiving, from an LMF, a first request message associated with selecting a second positioning method to replace a first positioning method; and transmitting, to the LMF, a first response message for the LMF to select the second positioning method.

In some embodiments of the present application, the processor is further configured to transmit capability information of the UE for the LMF to select the second positioning method.

In some embodiments of the present application, in the case that triggering a procedure of selecting the second positioning method is determined by the LMF, before receiving the first request message, the processor is further configured to transmit at least one of the following to the LMF: target device errors associated with the first positioning method; calculated or estimated positioning results associated with the first positioning method; error sources related to downlink measurement associated with the first positioning method; integrity key performance indicator (KPIs) for LMF based integrity with mobile originated (MO) location request (LR) service; calculated integrity results associated with the first positioning method; or information indicating that a positioning system using the first positioning method is unavailable or integrity events occur.

In some embodiments of the present application, before receiving the first request message, the processor is further configured to: determine whether to trigger a procedure of selecting the second positioning method; and transmit a positioning method reselection request to the LMF in the case of determining to trigger the procedure of selecting the second positioning method.

According to some embodiments of the present application, the processor is configured to determine to trigger the procedure of selecting the second positioning method in the case of: receiving error causes associated with the first positioning method from the LMF; or calculated or estimated positioning results associated with the first positioning method being lower than quality of service (QoS) requirements.

According to some embodiments of the present application, the processor is configured to determine to trigger the procedure of selecting the second positioning method in the case of a number of DoNotUse (DNU) flags being true associated with the first positioning method is larger than a preconfigured or configured threshold of DNU flags.

In some scenarios, the processor is configured to receive the preconfigured or configured threshold of DNU flags from the LMF.

In some scenarios, DNU flags associated with the first positioning method are DNU flags associated with downlink measurement, DNU flags associated with uplink measurement or DNU flags associated with assistance data.

In some cases, a DNU flag associated with downlink measurement is configured by the UE, a DNU flag associated with uplink measurement or assistance data is configured by a radio access network (RAN) node involved in a positioning system with the first positioning method, and the processor is configured to receive DNU flags associated with uplink measurement or assistance data from the RAN node or via the LMF.

In some cases, DNU flags are configured by the LMF, and the processor is configured to: transmit error sources associated with downlink measurements to the LMF so that the LMF will configure the DNU flag associated with downlink measurement based on the received error sources; and receive information related to the configured DNU flags from the LMF.

According to some embodiments of the present application, the processor is configured to determine to trigger the procedure of selecting the second positioning method in the case of determining that a positioning system using the first positioning method is unavailable or integrity events occur.

In some scenarios, the processor is configured to: receive an integrity KPI from the LMF; and compare integrity results with the integrity KPI to determine whether the positioning system is unavailable or whether there happen integrity events.

In some cases, the processor is configured to: report information indicating that the positioning system is unavailable or integrity events occur to the LMF.

Some yet other embodiments of the present application provide an exemplary LMF, which includes: a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to: transmit, to at least one positioning device of a positioning system, a first request message associated with selecting a second positioning method to replace a first positioning method; receive, from the at least one positioning device, a first response message for selecting the second positioning method; and determine the second positioning method at least based on the first response message and stored capability information of the positioning system.

Some yet other embodiments of the present application provide an exemplary method of supporting positioning method selection, which can be performed in an LMF. The exemplary method includes: transmitting, to at least one positioning device of a positioning system, a first request message associated with selecting a second positioning method to replace a first positioning method; receiving, from the at least one positioning device, a first response message for selecting the second positioning method; and determining the second positioning method at least based on the first response message and stored capability information of the positioning system.

In some embodiments of the present application, the processor is further configured to receive capability information of one or more positioning devices to be used to update the positioning system, and the second positioning method is selected further based on the requested capability information.

In some embodiments of the present application, the processor is configured to transmit the first request message in response to at least one of the following: receiving target device errors associated with the first positioning method from a UE of the at least one target positioning device; receiving radio network causes associated with the first positioning method from a RAN node of the at least one positioning device; receiving positioning results calculated or estimated by the UE associated with the first positioning method being lower than QoS requirements; or positioning results calculated or estimated by the LMF associated with the first positioning method being lower than QoS requirements.

In some embodiments of the present application, the processor is configured to transmit the first request message in response to a number of DNU flags being true is larger than a preconfigured or configured threshold of DNU flags.

According to some embodiments of the present application, the processor is configured to: receive error sources associated with downlink measurement from a UE of the at least one target positioning device; and configure DNU flags associated with the received error sources.

According to some embodiments of the present application, the processor is configured to: receive error sources associated with uplink measurement and/or associated with assistance data from a RAN node of the at least one positioning device; and configure DNU flags associated with the received error sources.

In some embodiments of the present application, the processor is configured to transmit the first request message in response to that: comparison of integrity results with integrity KPIs indicates that the positioning system is unavailable or integrity events occur; or receiving information indicating that the positioning system using the first positioning method is unavailable or integrity events occur.

According to some embodiments of the present application, the processor is configured to transfer the integrity KPIs to the UE, and the integrity results or the information indicating that the positioning system using the first positioning method is unavailable or integrity events occur are received from a UE of the at least one target positioning device; or the processor is configured to receive the integrity KPIs from the UE, and the integrity results are calculated by the LMF.

In some embodiments of the present application, the processor is configured to transmit the first request message in response to receiving a positioning method reselection request from a UE of the at least one target positioning device.

According to some embodiments of the present application, before receiving the positioning method reselection request, the processor is configured to transmit error causes to the UE.

According to some embodiments of the present application, before receiving the positioning method reselection request, the processor is configured to transmit a preconfigured or configured threshold of DNU flags for determining whether a number of DNU flag being true is larger than the threshold of DNU flags, to the at least positioning device.

In some scenarios, the processor is configured to: receive DNU flags configured by a RAN node of the at least one positioning device from the RAN node; and transmit the received DNU flags to the UE.

In some scenarios, the processor is configured to: configure DNU flags corresponding to error sources from the at least one positioning device; and transmit information related to the configured DNU flags to the UE.

According to some embodiments of the present application, before receiving the positioning method reselection request, the processor is configured to: receive information indicating that the positioning system is unavailable or integrity events occur from the UE.

In some scenarios, the processor is configured to: transmit integrity KPIs to the UE, so that the information indicating that the positioning system is unavailable or integrity events occur will be determined based on the integrity KPIs.

Given the above, embodiments of the present application propose a technical solution of positioning UE. When the positioning results are not accurate, the positioning system fails or is unavailable or integrity events occur during procedure (s) for LCS, a positioning method (re) selection procedure will be triggered and performed to improve the integrity of RAT-dependent positioning. Since unchanged information will be reused in the positioning procedure with the new selected positioning method, signaling and overhead will be reduced. Accordingly, embodiments of the present application will improve the existing positioning technology and facilitate the implementation of NR.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which advantages and features of the present application can be obtained, a description of the present application is rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. These drawings depict only exemplary embodiments of the present application and are not therefore intended to limit the scope of the present application.

FIG. 1 is a schematic diagram illustrating an exemplary wireless communication system according to some embodiments of the present application.

FIG. 2 is a flow chart illustrating an exemplary procedure of a method of supporting positioning method selection according to some embodiments of the present application.

FIG. 3 illustrates a block diagram of an apparatus of supporting positioning method selection according to some embodiments of the present application.

FIG. 4 illustrates a block diagram of an apparatus of supporting positioning method selection according to some other embodiments of the present application.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of the currently preferred embodiments of the present application and is not intended to represent the only form in which the present application may be practiced. It is to be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present application.

Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architecture and new service scenarios, such as 3GPP 5G, 3GPP LTE, and so on. It is contemplated that along with the developments of network architectures and new service scenarios, all embodiments in the present application are also applicable to similar technical problems. Moreover, the terminologies recited in the present application may change, which should not affect the principle of the present application.

FIG. 1 illustrates a schematic diagram of an exemplary wireless communication system 100 according to some embodiments of the present application.

As shown in FIG. 1, the wireless communication system 100 includes at least one BS 101 and at least one UE 102. In particular, the wireless communication system 100 includes one BS 101 and two UE 102 (e.g., a first UE 102a and a second UE 102b) for illustrative purpose. Although a specific number of BSs and UEs are illustrated in FIG. 1 for simplicity, it is contemplated that the wireless communication system 100 may include more or less BSs and UEs in some other embodiments of the present application.

The wireless communication system 100 is compatible with any type of network that is capable of sending and receiving wireless communication signals. For example, the wireless communication system 100 is compatible with a wireless communication network, a cellular telephone network, a time division multiple access (TDMA) -based network, a code division multiple access (CDMA) -based network, an orthogonal frequency division multiple access (OFDMA) -based network, an LTE network, a 3GPP-based network, a 3GPP 5G network, a satellite communications network, a high altitude platform network, and/or other communications networks.

The BS 101 may communicate with a core-network (CN) node (not shown) , e.g., a mobility management entity (MME) or a serving gateway (S-GW) , a mobility management function (AMF) , a user plane function (UPF) , or an LMF etc. via an interface. A BS also be referred to as an access point, an access terminal, a base, a macro cell, a node-B, an enhanced node B (eNB) , a gNB, a home node-B, a relay node, or a device, or described using other terminology used in the art. In 5G NR, a BS may also refer to as a RAN node or network apparatus. Each BS may serve a number of UE (s) within a serving area, for example, a cell or a cell sector via a wireless communication link. Neighbor BSs may communicate with each other as necessary, e.g., during a handover procedure for a UE.

The UE 102, e.g., the first UE 102a and second UE 102b should be understood as any type terminal device, which may include computing devices, such as desktop computers, laptop computers, personal digital assistants (PDAs) , tablet computers, smart televisions (e.g., televisions connected to the Internet) , set-top boxes, game consoles, security systems (including security cameras) , vehicle on-board computers, network devices (e.g., routers, switches, and modems) , or the like. According to an embodiment of the present application, the UE may include a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiver, or any other device that is capable of sending and receiving communication signals on a wireless network. In some embodiments, the UE may include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the UE may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art.

Besides RAT independent positioning techniques, RAT-dependent positioning techniques are also introduced for positioning UE etc. RAT-dependent positioning techniques involve many positioning methods, e.g., NR-enhanced cell identity (ECID) , multi-roundtrip time (RTT) , downlink (DL) -angle of departure (AoD) , DL-time difference of arrival (TDoA) , uplink (UL) -TDoA, and UL-angle-of-arrival (AoA) , etc. According to the latest Rel-18 SID, integrity of RAT-dependent positioning techniques will be studied. Integrity performance for different positioning methods may be different.

Depending on wireless communication deployments and scenarios, positioning of UE (or UE location estimation) can be done in either UE side or LMF side. For example, to support positioning of a target UE and delivery of location assistance data to the UE with NG-RAN access in 5G system (5GS) , location related functions are distributed as shown in the architecture provided in Figure 5.1-1 in TS 38.305 and the overall sequence of events applicable to the UE, NG-RAN and LMF for any location service are clarified in detail in TS 23.501 and TS 23.273.

According to 3GPP TS 38.305, for positioning a target UE, the LMF will decide the positioning method to be used based on a plurality of factors, e.g., LCS client type, required QoS, UE positioning capabilities, gNB positioning capabilities and NG-eNB positioning capabilities etc. In a current positioning procedure, when estimated positioning results are not reliable or the positioning system is unavailable, the positioning system may declare positioning failures and/or restart another positioning procedure (a new positioning procedure) . The new positioning procedure will include transfer procedures of capability information of UE and RAN node (s) (e.g., NG-eNB etc. ) participating in the positioning, assistance data for the positioning, and location information etc. Since partial information, e.g., information on UE capabilities, unchanged gNB or NG-eNB capabilities etc. may be the same as the former (or old or previous etc. ) positioning procedure, transferring such information will cause large signaling and latency overhead.

At least to solve the above issues, embodiments of the present application propose triggering and performing a positioning method reselection procedure (or a procedure of selecting a new positioning method, or a positioning method selection procedure) in the case of the positioning system being unavailable or integrity events occur. For example, technical solutions for integrity of RAT-dependent positioning techniques provided in embodiments of the present application include the triggering of the positioning method reselection procedure, and the signaling (or messages) procedure of the updated (or new) integrity assistance data and updated capability information to the LMF to assist determining (selecting or reselecting etc. ) the new positioning method.

Regarding "the updated or new integrity assistance data, " it may refer to the information that needs to be transferred after triggering the positioning method selection (or reselection) procedure for RAT-dependent positioning. According to R1-2205344 RAN1#109 e-meeting, exemplary new integrity assistance data may be the information caused by UE moving, including dynamic errors and radio propagation environment errors. Exemplary dynamic errors include uncertainty of line of sight (LoS) indicator and/or non LoS (NLoS) indicator; and uncertainty of measurements, e.g., UE or network (NW) wrongly assessment of LoS/NLoS, positioning reference signal (PRS) reference signal received power (RSRP) , PRS signal to interference plus noise ratio (SINR) , etc. Exemplary radio propagation environment errors include radio link failures and/or beam failures, handover failures, poor coverage detection from UE, spoofing, and interference etc.

FIG. 2 is a flow chart illustrating an exemplary procedure of a method of supporting positioning method selection according to some embodiments of the present application. Although the method is illustrated in a system level by a target apparatus, e.g., a UE 102 as shown in FIG. 1 and a CN function entity, e.g., an LMF, persons skilled in the art can understand that the method implemented in the UE and that implemented in the LMF can be separately implemented and incorporated by other apparatus with the like functions.

Referring to FIG. 2, instead of starting (restarting or performing etc. ) a totally new positioning procedure, according to some embodiments of the present application, when positioning results using a first positioning method are not accurate, or the positioning system (or current positioning system or the like) using a first positioning method (current positioning method, or former positioning method, or old positioning method or the like) fails or is (deemed or declared or determined or the like) unavailable or integrity events occur, a positioning method selection procedure will be triggered and performed to select a second positioning method (updated positioning method, or (re) selected positioning method, or new positioning method or the like) to replace the first positioning method. The capability information that is the same as the former (or old or failed or the like) positioning procedure using the first positioning method, e.g., UE's capabilities, unchanged RAN node (s) ' capabilities (e.g., gNB(s) 's capabilities etc. will be stored and used in the new positioning procedure associated with the second positioning procedure to reduce signaling and latency.

Specifically, in response to an exemplary positioning method selection procedure being triggered, in step 201, the LMF may transmit, to the UE, a first request message associated with selecting the second positioning method to replace the first positioning method. In exemplary scenarios, although the UE is the target device, it also acts as a positioning device for the positioning. Exemplary first request message is a new integrity assistance data request, which requests the information that needs to be transferred after triggering a procedure of selecting the second positioning method. Accordingly, in step 202, the UE will receive the first request message. The first request message is associated with selecting the second positioning method. In some other embodiments of the present application, the first request message may also be transmitted to other positioning device (s) (if any) , e.g., a gNB of the positioning system associated with selecting the second positioning method (or potential to be used to update the positioning system) . That is, other positioning device (s) may be involved in the updated positioning system, e.g., the positioning system using the second positioning method. Persons skilled in the art should well know that although the old positioning system (or the like) and the updated positioning system are used for simplicity and clearness, the substance of the positioning system may not change along with different positioning methods. Other positioning device (s) that may be involved in the positioning systems using the first positioning method and the second positioning method for positioning the UE may be the same or partially same or totally different.

In step 204, the positioning device (s) , e.g., the UE that receives the first request message may transmit a first response message to the LMF, which can be used for selecting the second positioning method. For example, the first response message may indicate the new integrity assistance data, e.g., the information caused by UE movement, including dynamic errors and radio propagation environment errors etc. Accordingly, in step 205, the LMF will receive the first response message from the positioning device (s) at least including the UE.

At least based on the first response message and stored capability information of the positioning system, the LMF will determine (or select, or reselect) the second positioning method in step 207. For example, the LMF will reselect a second positioning method from the remaining RAT-dependent positioning methods except for the first positioning method at least according to the received new integrity assistance data and the stored capability information, e.g., unchanged UE capability information and unchanged gNB capability information.

In some cases, e.g., new positioning device (s) may be potential to be involved in the updated positioning system compared with that using the first positioning method, the LMF may further transmit a second request message to one or more positioning devices (e.g., new gNB) that are associated with selecting the second positioning method, requesting capability information of the one or more positioning devices or other information associated with selecting the second positioning method. Accordingly, the LMF will receive a second response message from the one or more positioning devices in response to the second request message, indicating the requested capability information or other information associated with selecting the second positioning method. Besides the first response message and stored capability information, the second positioning method will be selected also based on the requested capability information or other information associated with selecting the second positioning method. The at least one positioning device receiving the first request message may be the same or different from the one or more positioning devices receiving the second request message. For example, in some cases, the one or more positioning devices are only new positioning devices compared with that using the first positioning method.

Then, the LMF will deliver positioning assistance data to the positioning device (s) targeting for the second positioning method. The new positioning procedure associated with the second positioning method will be performed.

Whether positioning results using the first positioning method is inaccurate, a positioning system using a first positioning method fails or is (deemed or declared or determined or the like) unavailable or integrity events occur can be determined in various manners according to some embodiments of the present application. Accordingly, a positioning method selection procedure will be triggered in various manners. For example, the positioning method selection procedure may be triggered by the LMF or UE in the case of at least one condition (or trigger condition) being satisfied, which may be during the positioning procedure, positioning integrity procedure, and/or other procedure (s) . Regarding the positioning procedure and positioning integrity procedure, they are separate procedures in some embodiments of the present application or are merged into a single procedure in some other embodiments of the present application. In the case that at least one of the positioning procedure or positioning integrity procedure may be a part of another whole procedure, the other whole procedure may also be referred to as a super procedure for simplicity and clearness.

Hereafter, more detailed embodiments of the present application will be illustrated in view of different trigger scenarios, e.g., by LMF or UE in the positioning procedure or positioning integrity procedure. Persons skilled in the art should well know that due to the consistency between the LMF side and remote side, although some embodiments are illustrated only concerning on one side as an example, the corresponding operations except for special operations in the other side should also be clearly determined.

Scenarios I: LMF determines whether to trigger a positioning method selection procedure

In Scenarios I, the LMF will determine whether positioning results using the first positioning method is inaccurate, or whether a positioning system using the first positioning method fails, or whether a positioning system using the first positioning method is unavailable, or whether integrity events occur, and determine whether to trigger a positioning method selection procedure. Whether positioning results using the first positioning method is inaccurate, or whether a positioning system using the first positioning method fails, or whether a positioning system using the first positioning method is unavailable, or whether integrity events occur can be determined in various manners in Scenarios I. Thus, the trigger conditions for a positioning method selection procedure are also various.

For example, in the perspective of the LMF, it may determine to trigger a positioning method selection procedure in response to at least one of the following: receiving target device errors associated with the first positioning method from a UE of at least one target positioning device; or receiving radio network causes associated with the first positioning method from a RAN node of the at least one positioning device; or receiving positioning results calculated or estimated by the UE associated with the first positioning method being lower than QoS requirements; or positioning results calculated or estimated by the LMF associated with the first positioning method being lower than QoS requirements. The LMF may transmit the first request message in the case of determining to trigger a positioning method selection procedure. In the perspective of the UE, it may transmit at least one of the following to the LMF in Scenarios I so that the LMF will determine whether to trigger a positioning method selection procedure: target device errors associated with the first positioning method; calculated or estimated positioning results associated with the first positioning method; error sources related to downlink measurement associated with the first positioning method; integrity KPIs for LMF based integrity with MO-LR service; calculated integrity results associated with the first positioning method; or information indicating that a positioning system using the first positioning method is unavailable or integrity events occur.

According to some embodiments of the present application, the LMF will determine whether to trigger a positioning method selection procedure during the positioning procedure or a super procedure at least including the positioning procedure or the like. For example, the LMF may determine that a positioning system using the first positioning method fails or positioning results are inaccurate and to trigger a positioning method selection procedure in response to at least one specific error (or error cause) indicated from positioning device (s) , e.g., the UE and/or RAN node (s) . For another example, the LMF may trigger a positioning method selection procedure in response to calculated positioning results and/or estimated positioning results cannot satisfy the QoS requirements.

Exemplary specific errors from the UE may be target device error (s) (e.g., represented by a parameter TargetDeviceError) associated with the first positioning method from the UE, e.g., via a long term evolution (LTE) positioning protocol (LPP) message (or signaling) . For example, in the case that the LMF receives at least one specific error from the UE, e.g., target device error (s) associated with DL-TDoA, DL-AoD, or multi-RTT etc., respectively identified by parameters NR-DL-TDoA-TargetDeviceErrorCauses, NR-DL-AoD-TargetDeviceErrorCauses, NR-Multi-RTT-TargetDeviceErrorCauses, and/or other target device error (s) in an LPP provide location information message or other LPP message, the LMF may trigger the positioning method selection procedure. Persons skilled in the art should well know that the name of the parameters are only used as examples for clearly illustrating the embodiments, which may be replaced by other names, and thus should not be unduly used to limit the scope of the present application.

Exemplary specific errors from the RAN node (s) may be radio network cause (s) from at least one RAN node, e.g., via the information element (IE) "Radio Network Layer Cause" , from at least one gNB participating in the positioning using the first positioning method. For example, in the case that the LMF receives at least one specific error from the RAN node (s) , e.g., "Requested Item Temporarily not Available, " "Requested Item not Supported, " "Serving NG-RAN node changed, " "Requested Item not Supported on Time" and/or other specific error (s) from gNB (s) , the LMF may trigger the positioning method reselection procedure.

Regarding the calculated positioning results and/or estimated positioning results, they will be illustrated respectively in view of UE-based positioning and LMF-based positioning considering that positioning of the UE can be done in either UE side (UE-based positioning) or LMF side (LMF-based positioning) .

In the scenarios of the UE-based positioning, the UE will calculate and/or estimate positioning results. The UE may send the calculated positioning results and/or estimated positioning results to the LMF using the LPP location information message or other LPP message. The LMF will compare the calculated and/or estimated positioning results with the required QoS to determine whether to trigger the positioning method selection procedure. For example, in the case that the calculated and/or estimated positioning results cannot satisfy the required QoS, the LMF may determine that the positioning system using the first positioning method fails or positioning results are inaccurate and determine to trigger the positioning method selection procedure.

In the scenarios of the LMF-based positioning, the LMF will calculate and/or estimate the positioning results. Similarly, the LMF will compare the calculated and/or estimated positioning results with the required QoS to determine whether to trigger the positioning method selection procedure. For example, in the case that the calculated and/or estimated positioning results cannot satisfy the required QoS, the LMF may determine that the positioning system using the first positioning method fails or positioning results are inaccurate and determine to trigger the positioning method selection procedure.

Although the above embodiments associated with the specific errors and associated with calculated and/or estimated positioning results are respectively illustrated, persons skilled in the art should well know that they can be applied in combination.

According to some other embodiments of the present application, the LMF will determine whether to trigger a positioning method selection procedure during the positioning integrity procedure (also referred to as an integrity procedure) or a super-procedure at least including the positioning integrity procedure or the like. A positioning integrity procedure may be a UE-based integrity procedure (or UE-based integrity) or LMF-based integrity procedure (or LMF-based integrity) based on whether the integrity results are calculated in the UE side or the LMF side. In the scenarios of UE-based integrity, the integrity will be calculated in the UE side; and in the scenarios of LMF-based integrity, the integrity will be calculated in the LMF side. The trigger conditions are associated with DNU flags, or integrity results, or the combination of DNU flags and integrity results. For example, the LMF may trigger a positioning method selection procedure in response to that the number of DNU flags being true (e.g., identified by parameter "DNU-true" ) is larger than a predefined or (pre) configured threshold of DNU flags. An exemplary threshold of DNU flags may be configured by the LMF. For another example, the LMF may trigger a positioning method selection procedure in response to that comparison of integrity results with integrity KPIs indicates the positioning system using the first positioning method unavailable or integrity event occurrence.

In the case that whether to trigger a positioning method selection procedure is based on DNU flags associated with error sources, there are various embodiments considering that the error sources are various. For example, in some embodiments of the present application, DNU flags can be configured (or marked) by the LMF, which may be based on error sources related to assistance data, error sources related to DL measurement and/or error sources related to UL measurement.

In the scenarios of error sources related to assistance data (also referred to as error source related to assistance data transfer procedures) , RAN node (s) , e.g., NG-RAN nodes for positioning will provide the error sources related to assistance data to the LMF by an NR positioning protocol A (NRPPa) message (or signaling) . An exemplary error source related to assistance data may be an error source related to inter-TRP synchronization, TRP location, or antenna reference point (ARP) location, etc. An exemplary NRPPa message may be TRP configuration information exchange message. Based on the received error sources related to assistance data, the LMF will configure the DNU flag associated with each error source to be true or false in a corresponding IE, e.g., NR-Integrity-ServiceAlert, and/or NR-RealTimeIntegrity etc. For example, a DNU flag related to inter-TRP synchronization being configured may be NR-RTD-InfoDoNotUse, a DNU flag related to TRP location being configured may be NR-TRP-LocationInfoDoNotUse, and a DNU flag related to ARP location being configured may be ARPLocationInformationDoNotUse, etc. In the case that the number of DNU flags related to the assistance data being true is larger than the threshold of DNU flags, the LMF may trigger a positioning method selection procedure.

In the scenarios of error sources related to DL measurement (also referred to as error sources related to DL measurement transfer procedure) , the UE may provide the error sources related to DL measurement to the LMF by LPP message (s) or the like, e.g., LPP provide location information messages. An exemplary error source related to DL measurement may be an error source related to RSTD measurement, or UE receiving (Rx) -transmitting (Tx) time difference measurement etc. Based on the received error sources related to DL measurement, the LMF will configure the DNU flag to be true or false associated with each error source, e.g., in corresponding IE NR-Integrity-DL-MeasurementAlert. For example, the LMF may configure a DNU flag related to RSTD measurement by generating NR-RSTDDoNotUse, or configure a DNU flag related to UE Rx-Tx time difference measurement by generating NR-UE-RxTxTimeDiffDoNotUse etc., which indicates whether the corresponding DL measurement error can be used for calculating integrity. In the case that the number of DNU flags related to DL measurement errors is larger than the threshold of DNU flags, the LMF will trigger a positioning method selection procedure.

In the scenarios of error sources related to UL measurement (also referred to as error sources related to UL measurement transfer procedure) , RAN node (s) , e.g., NG-RAN nodes for positioning may provide the error sources related to UL measurement to the LMF by NRPPa message (s) or the like, e.g., NRPPa measurement response messages. An exemplary error source related to UL measurement may be an error source related to RTOA measurement, AoA measurement, or gNB Rx-Tx time difference measurement etc. Based on the received error sources related to UL measurement, the LMF will configure the DNU flag to be true or false associated with each error source, e.g., in a corresponding IE (e.g., NR-Integrity-UL-MeasurementAlert) . For example, the LMF may configure a DNU flag related to RTOA measurement by generating NR-RTOADoNotUse, configure a DNU flag related to AoA measurement by generating NR-AoADoNotUse, or configure a DNU flag related to gNB Rx-Tx time difference measurement by generating NR-gNB-RxTxTimeDiffDoNotUse etc., which indicates whether the corresponding UL measurement error can be used for calculating integrity. In the case that the number of DNU flags related to UL measurement errors is larger than the threshold of DNU flags, the LMF will trigger a positioning method selection procedure.

Although the above embodiments associated with the error sources related to assistance data, error sources related to DL measurement and/or error sources related to UL measurement are respectively illustrated for simplicity and clearness, persons skilled in the art should well know that they can be applied in combination. That is, the number of DNU flags being true associated with the first positioning method will consider all of the error sources (if any) .

In the case that whether to trigger a positioning method selection procedure is based on integrity results, they will also be respectively illustrated in view of UE-based integrity or LMF-based integrity. Integrity results leading to system unavailable or integrity event occurring may be represented by binary flag=1 indicating system unavailable or binary flag=0 with integrity event occurring. Exemplary integrity KPI may be target integrity risk (TIR) , alert limit (AL) , time-to-alert (TTA) , etc. Exemplary calculated integrity results may be protection level (PL) etc.

Integrity KPI may be transferred between the UE and the LMF in some scenarios (the transferred integrity KPI may also be referred to as source of integrity KPI or source of KPI) . For example, in the scenarios of UE-based integrity with mobile terminated (MT) -LR and deferred MT-LR services, the integrity KPI may be transferred from the LMF to the UE via LPP message (s) or the like, e.g., LPP request location information message (s) , which reuses the agreements on GNSS integrity. In the scenarios of LMF-based integrity with MO-LR service, the integrity KPI may be transferred from the UE to the LMF, which may be carried in MO-LR location request message or in legacy LPP procedures (e.g., legacy LPP procedures for capability information, assistance data, or location information) .

Herein (throughout the specification) , only AL and PL will be illustrated as examples. In some embodiments of the present application, PL being larger than AL (PL>AL) indicates the corresponding positioning system unavailable, and PL being smaller than AL (PL<AL) indicates the corresponding positioning system available. However, integrity event (s) , e.g., misleading information (MI) , or Hazardous MI (HMI) etc. may occur even in the case of PL<AL indicating positioning system available.

In the scenarios of the UE-based integrity (e.g., MT-LR and deferred MT-LR services) , the UE will report the calculated integrity results, e.g., PL to the LMF. The LMF will compare the calculated integrity results with the integrity KPI, e.g., AL. In the case that PL is larger than AL, which indicates the positioning system unavailable, the LMF may trigger the positioning method selection procedure. In the case that PL is smaller than AL, which indicates the positioning system available, while integrity event (s) occurs, the LMF may also trigger the positioning method selection procedure. Otherwise, in the case that the positioning system is available and no integrity event happens, the LMF will not trigger the positioning method selection procedure. In some embodiments of the present application, the UE will compare the calculated integrity results with the integrity KPI and transmit the information indicates the comparison result to the LMF, e.g., transmitting information indicating that a positioning system using the first positioning method is unavailable or integrity events occur.

In the scenarios of the LMF-based integrity, the LMF will calculate the integrity results, e.g., PL and compare the integrity results with the integrity KPI, e.g., AL. Similarly, in the case that PL is larger than AL, which indicates the positioning system unavailable, the LMF may trigger the positioning method selection procedure. In the case that PL is smaller than AL while integrity event (s) occurs, the LMF may also trigger the positioning method selection procedure. Otherwise, in the case that the positioning system is available and no integrity event happens, the LMF will not trigger the positioning method selection procedure.

Scenarios II: UE determines whether to trigger a positioning method selection procedure

Besides the manner that the LMF determines whether to trigger a positioning method selection procedure, embodiments of the present application also provide the manner that the UE determines whether to trigger a positioning method selection procedure. In the perspective of the UE, it may determine whether to trigger a procedure of selecting the second positioning method, and transmit a positioning method selection request (or positioning method reselection request or the like) to the LMF in the case of determining to trigger the procedure of selecting the second positioning method. In the perspective of the LMF, it may transmit the first request message in response to receiving a positioning method selection request from the UE.

Similar to Scenarios I, the positioning method selection procedure may be triggered by the UE both in positioning procedure and positioning integrity procedure in response to trigger condition (s) being satisfied.

Specifically, according to some embodiments of the present application, the UE will determine whether to trigger a positioning method selection procedure during the positioning procedure (or a super-procedure at least including the positioning procedure or the like) . For example, the UE may trigger a positioning method selection procedure in response to at least one specific error indicated from the LMF. For another example, the UE may trigger a positioning method selection procedure in response to that calculated positioning results and/or estimated positioning results cannot satisfy the QoS requirements.

Exemplary specific errors from the LMF may be location server error (s) (e.g., identified by a parameter LocationServerError) associated with the first positioning method from the LMF, e.g., via an LPP message or the like. An exemplary LPP message or signaling may be an LPP provide assistance data message. For example, the UE may receive at least one specific error from the LMF, e.g., location server error (s) related to DL-TDOA, DL-AoD or multi-RTT etc., which may be respectively identified by parameters NR-DL-TDOA-LocationServerErrorCauses, NR-DL-AoD-LocationServerErrorCauses, or NR-Multi-RTT-LocationServerErrorCauses etc. Accordingly, the UE may determine to trigger the positioning method selection procedure and send a positioning method selection request to the LMF, e.g., in an Abort message or another LPP message to the LMF.

Regarding the calculated positioning results and/or estimated positioning results, only the UE-based positioning will be considered in Scenarios II. The UE will compare the calculated and/or estimated positioning results with the QoS requirement to determine whether to trigger the positioning method selection procedure. For example, in the case that the calculated and/or estimated positioning results cannot satisfy the required QoS, the UE may determine that the positioning system using the first positioning method fails or positioning results are inaccurate and to trigger the positioning method selection procedure. The UE may send a positioning method selection request to the LMF to trigger the positioning method selection procedure, wherein the positioning method selection request may be integrated in the LPP provide location information message or in an LPP message separate from the LPP provide location information message.

Similarly, although the above embodiments associated with the specific errors and associated with calculated and/or estimated positioning results are respectively illustrated, persons skilled in the art should well know that they can be applied in combination.

According to some other embodiments of the present application, the UE will determine whether to trigger a positioning method selection procedure during the positioning integrity procedure or a super-procedure at least including the positioning integrity procedure or the like. Similarly, a positioning integrity procedure may be a UE-based integrity procedure (or UE-based integrity) or LMF-based integrity procedure (or LMF-based integrity) based on whether the integrity results are calculated in the UE side or the LMF side. The trigger conditions are associated with DNU flag, or integrity results or the combination of them. For example, the UE may trigger a positioning method selection procedure in response to that the number of integrity parameters with DNU flags being true is larger than a predefined or (pre) configured threshold of DNU flags. An exemplary threshold of DNU flags may be configured by the LMF. For another example, the UE may trigger a positioning method selection procedure in response to that comparison of integrity results with integrity KPIs indicates the positioning system using the first positioning method unavailable or integrity event occurrence.

In the case that whether to trigger a positioning method selection procedure is based on DNU flags, the DNU flags can be configured by the UE, or other positioning device (s) (e.g., positioning RAN node (s) ) , or LMF.

In the case that DNU flags are configured by the UE and/or other positioning device (s) , the threshold of DNU flags (pre) configured by the LMF may be transferred to the UE via an LPP message, e.g., LPP request capability information message or LPP provide assistance data message or the like.

In some cases, the UE may configure the DNU flags based on error sources related to DL measurement similar to Scenarios I. For example, the UE may generate an IE, e.g., NR-Integrity-DL-MeasurementAlert to indicate whether the corresponding DL measurement error can be used for calculating integrity. An exemplary DNU flag may be configured by the UE based on error sources related to RSTD measurement, e.g., identified by NR-RSTDDoNotUse, or configured by the UE based on error sources related to UE Rx-Tx time difference measurement, e.g., identified by NR-UE-RxTxTimeDiffDoNotUse, etc.

In some cases, the positioning RAN node (s) may configure the DNU flags based on error sources related to assistance data and UL measurement similar to Scenarios I.

For example, the positioning RAN node (s) , e.g., gNB may generate corresponding IE (s) , e.g., NR-Integrity-ServiceAlert, and/or NR-RealTimeIntegrity etc. to indicate whether the corresponding assistant data errors can be used for calculating integrity. An exemplary DNU flag may be configured by the positioning RAN node (s) based on error sources related to each assistance data elements in the corresponding IE, e.g., based on error sources related to RTD, e.g., identified by NR-RTD-InfoDoNotUse, or based on error sources related to TRP location, e.g., identified by NR-TRP-LocationInfoDoNotUse, or based on error sources related to ARP location, e.g., identified by RPLocationInformationDoNotUse, etc.

For another example, the positioning RAN node (s) , e.g., gNB may generate IE(s) , e.g., NR-Integrity-UL-MeasurementAlert to indicate whether the corresponding UL measurement errors can be used for calculating integrity. An exemplary DNU flag may be configured by the positioning RAN node (s) based on error sources related to each UL measurement element in the corresponding IE, e.g., based on error sources related to RTOA measurement (e.g., identified by NR-RTOADoNotUse) , or based on error sources related to AoA measurement (e.g., identified by NR-AoADoNotUse) , or by error sources related to gNB Rx-Tx time difference measurement (e.g., identified by NR-gNB Rx-Tx Time DifferenceDoNotUse) etc.

The positioning RAN node (s) , e.g., gNB will send the configured DNU flags to the UE for DNU flag configuration in various manners. In some cases, the RAN node may directly transmit the configured DNU flags to the UE, e.g., via radio resource control (RRC) message or the like. In some other cases, the RAN node may transmit the configured DNU flags to the UE via the LMF. For example, the RAN node may transmit the configured DNU flags to the LMF via NRPPa message, and then the LMF will transmit the received DNU flags to the UE via the LPP message or the like.

In the case that the number of the DNU flags configured to be true, e.g., the number of “DNU=true” configured by the UE based on the DL measurement error, and/or the “DNU=true” configured by the RAN node (s) based on the assistant data error and/or UL measurement error is larger than the corresponding threshold of DNU flags, the UE may determine to trigger the positioning method selection procedure and send the positioning method selection request to the LMF.

In some other embodiments of the present application, DNU flag (s) may be configured by the LMF, which may be based on error sources related to assistance data, error sources related to DL measurement and/or error sources related to UL measurement similar to Scenarios I. Similarly, a threshold will be provided for the UE to compare it with the number of DNU flags being true. For example, a threshold preconfigured or configured by the LMF may be transferred to the UE by an LPP message or the like, e.g., by LPP request capability information message or LPP provide assistance data message. The LMF will configure the DNU flag for each error source provided by the UE and gNB, e.g., error source related to assistance data, DL measurements, and/or UL measurements etc. Details are similar to Scenarios I and thus will not be repeated.

The LMF will transmit the information related to the configured DNU flags to the UE. Based on the information related to the configured DNU flags, the UE will determine whether the number of DNU flags being true is larger than the threshold of DNU flags. For example, the LMF may directly transmit the number of DNU flags being true to the UE in assistance data, or indicate information of the DNU flags being true to the UE in assistance data so that the UE can determine the number of DNU flags being true. In the case that the number of DNU flags being true is larger than the threshold of DNU flags, the UE may determine to trigger the positioning method selection procedure and send the positioning method selection request to the LMF.

Similar to Scenarios I, whether to trigger a positioning method selection procedure can also be determined based on integrity results in the positioning integrity procedure according to some other embodiments of the present application. Different from Scenarios I, only UE-based integrity will be considered in Scenarios II. Similarly, integrity results leading to positioning system unavailable may be binary flag=1 (e.g., PL>AL) indicating positioning system unavailable. Integrity results leading to integrity event occurrence may be binary flag=0 (PL<AL) with integrity event (e.g., MI, HMI) occurring. In some embodiments of the present application, the UE may also report the binary flag, e.g., 0 and 1 to the LMF, to indicate whether the positioning system is available or not via LPP provide location information message or another LPP message.

In the case that the binary flag is 1 (e.g., PL>AL indicating system unavailable) or the binary flag is 0 with integrity event occurring (e.g., PL<AL with integrity event, the UE may determine to trigger a positioning method selection procedure and send a positioning method selection request to the LMF.

Besides methods of supporting positioning method selection, some embodiments of the present application also provide an apparatus of supporting positioning method selection. For example, FIG. 3 illustrates a block diagram of an apparatus of supporting positioning method selection 300 according to some embodiments of the present application.

As shown in FIG. 3, the apparatus 300 may include at least one non-transitory computer-readable medium 301, at least one receiving circuitry 302, at least one transmitting circuitry 304, and at least one processor 306 coupled to the non-transitory computer-readable medium 301, the receiving circuitry 302 and the transmitting circuitry 304. The at least one processor 306 may be a central processing unit (CPU) , a digital signaling processing (DSP) , a microprocessor etc. The apparatus 300 may be a UE or LMF configured to perform a method illustrated in the above or the like.

Although in this figure, elements such as the at least one processor 306, transmitting circuitry 304, and receiving circuitry 302 are described in the singular, the plural is contemplated unless a limitation to the singular is explicitly stated. In some embodiments of the present application, the receiving circuitry 302 and the transmitting circuitry 304 can be combined into a single device, such as a transceiver. In certain embodiments of the present application, the apparatus 300 may further include an input device, a memory, and/or other components.

In some embodiments of the present application, the non-transitory computer-readable medium 301 may have stored thereon computer-executable instructions to cause a processor to implement the method with respect to a remote apparatus, e.g., a UE as described above. For example, the computer-executable instructions, when executed, cause the processor 306 interacting with receiving circuitry 302 and transmitting circuitry 304, so as to perform the steps with respect to a UE as depicted above.

In some embodiments of the present application, the non-transitory computer-readable medium 301 may have stored thereon computer-executable instructions to cause a processor to implement the method with respect to a CN node, e.g., an LMF as described above. For example, the computer-executable instructions, when executed, cause the processor 306 interacting with receiving circuitry 302 and transmitting circuitry 304, so as to perform the steps with respect to an LMF as depicted above.

FIG. 4 is a block diagram of an apparatus of supporting positioning method selection 400 according to some other embodiments of the present application.

Referring to FIG. 4, the apparatus 400, for example a UE or an LMF may include at least one processor 402 and at least one transceiver 404 coupled to the at least one processor 402. The transceiver 404 may include at least one separate receiving circuitry 406 and transmitting circuitry 408, or at least one integrated receiving circuitry 406 and transmitting circuitry 408. The at least one processor 402 may be a CPU, a DSP, a microprocessor etc.

According to some embodiments of the present application, when the apparatus 400 is a remote apparatus, e.g., a UE. The UE includes a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to: receive, from an LMF, a first request message associated with selecting a second positioning method to replace a first positioning method; and transmit, to the LMF, a first response message for the LMF to select the second positioning method.

According to some other embodiments of the present application, when the apparatus 400 is a CN node, e.g., an LMF. The LMF includes a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to: transmit, to at least one positioning device of a positioning system, a first request message associated with selecting a second positioning method to replace a first positioning method; receive, from the at least one positioning device, a first response message for selecting the second positioning method; and determine the second positioning method at least based on the first response message and stored capability information of the positioning system.

The method according to embodiments of the present application can also be implemented on a programmed processor. However, the controllers, flowcharts, and modules may also be implemented on a general purpose or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an integrated circuit, a hardware electronic or logic circuit such as a discrete element circuit, a programmable logic device, or the like. In general, any device capable of implementing the flowcharts shown in the figures may be used to implement the processor functions of this application. For example, an embodiment of the present application provides an apparatus, including a processor and a memory. Computer programmable instructions for implementing a method are stored in the memory, and the processor is configured to perform the computer programmable instructions to implement the method. The method may be a method as stated above or other method according to an embodiment of the present application.

An alternative embodiment preferably implements the methods according to embodiments of the present application in a non-transitory, computer-readable storage medium storing computer programmable instructions. The instructions are preferably executed by computer-executable components preferably integrated with a network security system. The non-transitory, computer-readable storage medium may be stored on any suitable computer readable media such as random access memory (RAMs) , read only memory (ROMs) , flash memory, electrically erasable programmable read only memory (EEPROMs) , optical storage devices (compact disc (CD) or digital video disc (DVD) ) , hard drives, floppy drives, or any suitable device. The computer-executable component is preferably a processor but the instructions may alternatively or additionally be executed by any suitable dedicated hardware device. For example, an embodiment of the present application provides a non-transitory, computer-readable storage medium having computer programmable instructions stored therein. The computer programmable instructions are configured to implement a method as stated above or other method according to an embodiment of the present application.

In addition, in this disclosure, the terms "includes, " "including, " or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "a, " "an, " or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element. Also, the term "another" is defined as at least a second or more. The terms "having, " and the like, as used herein, are defined as "including. "

Claims

A user equipment (UE) , comprising:

a transceiver; and

a processor coupled to the transceiver, wherein the processor is configured to:

receive, from a location management function (LMF) , a first request message associated with selecting a second positioning method to replace a first positioning method; and

transmit, to the LMF, a first response message for the LMF to select the second positioning method.
The UE of claim 1, wherein, in the case that triggering a procedure of selecting the second positioning method is determined by the LMF, before receiving the first request message, the processor is further configured to transmit at least one of the following to the LMF:

target device errors associated with the first positioning method;

calculated or estimated positioning results associated with the first positioning method;

error sources related to downlink measurement associated with the first positioning method;

integrity key performance indicators (KPIs) for LMF based integrity with mobile originated location request (MO-LR) service;

calculated integrity results associated with the first positioning method; or

information indicating that a positioning system using the first positioning method is unavailable or integrity events occur.
The UE of claim 1, wherein, before receiving the first request message, the processor is further configured to:

determine whether to trigger a procedure of selecting the second positioning method; and

transmit a positioning method reselection request to the LMF in the case of determining to trigger the procedure of selecting the second positioning method.
The UE of claim 3, wherein, the processor is configured to determine to trigger the procedure of selecting the second positioning method in the case of:

receiving error causes associated with the first positioning method from the LMF; or

calculated or estimated positioning results associated with the first positioning method being lower than quality of service (QoS) requirements.
The UE of claim 3, wherein, the processor is configured to determine to trigger the procedure of selecting the second positioning method in the case of a number of DoNotUse (DNU) flags being true associated with the first positioning method is larger than a preconfigured or configured threshold of DNU flags.
The UE of claim 5, wherein, DNU flags associated with the first positioning method are DNU flags associated with downlink measurement, DNU flags associated with uplink measurement or DNU flags associated with assistance data.
The UE of claim 6, wherein, a DNU flag associated with downlink measurement is configured by the UE, a DNU flag associated with uplink measurement or assistance data is configured by a radio access network (RAN) node involved in a positioning system with the first positioning method, and the processor is configured to receive DNU flags associated with uplink measurement or assistance data from the RAN node or via the LMF.
The UE of claim 6, wherein, DNU flags are configured by the LMF, and the processor is configured to:

transmit error sources associated with downlink measurements to the LMF so that the LMF will configure the DNU flag associated with downlink measurement based on the received error sources; and

receive information related to the configured DNU flags from the LMF.
The UE of claim 3, wherein, the processor is configured to determine to trigger the procedure of selecting the second positioning method in the case of determining that a positioning system using the first positioning method is unavailable or integrity events occur.
The UE of claim 9, wherein, the processor is configured to:

receive an integrity key performance indicator (KPI) from the LMF; and

compare integrity results with the integrity KPI to determine whether the positioning system is unavailable or whether there happen integrity events.
The UE of claim 10, wherein, the processor is configured to:

report information indicating that the positioning system is unavailable or integrity events occur to the LMF.
A location management function (LMF) , comprising:

a transceiver; and

a processor coupled to the transceiver, wherein the processor is configured to:

transmit, to at least one positioning device of a positioning system, a first request message associated with selecting a second positioning method to replace a first positioning method;

receive, from the at least one positioning device, a first response message for selecting the second positioning method; and

determine the second positioning method at least based on the first response message and stored capability information of the positioning system.
The LMF of claim 12, wherein, the processor is further configured to receive capability information of one or more positioning devices to be used to update the positioning system, and the second positioning method is selected further based on the requested capability information.
The LMF of claim 12, wherein, the processor is configured to:

receive error sources associated with uplink measurement and/or associated with assistance data from a radio access network (RAN) node of the at least one positioning device;

configure DoNotUse (DNU) flags associated with the received error sources; and

transmit the first request message in response to a number of DNU flags being true is larger than a preconfigured or configured threshold of DNU flags.
A method of supporting positioning method selection, comprising:

receiving, from a location management function (LMF) , a first request message associated with selecting a second positioning method to replace a first positioning method; and

transmitting, to the LMF, a first response message for the LMF to select the second positioning method.