Positioning method, device, storage medium, computer program, and chip system

Abstract

A positioning method, an apparatus, and a storage medium are provided, which are applied to the field of communication technology, and the method includes: a first network element receiving a first request, where the first request is used to request performing positioning based on at least one ranging terminal; a first network element determining a ranging source terminal, where the ranging source terminal is one of the at least one ranging terminal, and the ranging source terminal satisfies a first requirement; and a first network element instructing the ranging source terminal to start ranging.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a positioning method, apparatus, and storage medium.

Background Art

[0002] Location based service / location service (LBS / LCS) is a service that obtains the location information of a terminal through a wireless communication network or another positioning system, and then provides various location-related information to a user based on a geographic information system.

[0003] Currently, in the process of implementing location based service / location service, it is necessary to select a ranging start source terminal (start source UE) for starting ranging with another terminal to obtain ranging information, and thereby perform positioning based on the ranging information. How to select an appropriate ranging start source terminal to reduce network interaction is a technical problem that needs to be solved currently.

Summary of the Invention

[0004] Embodiments of this application provide a positioning method, apparatus, and storage medium for selecting an appropriate ranging terminal.

[0005] According to a first aspect, there is provided a positioning method including: a first network element receiving a first request, where the first request is used to request to perform positioning based on at least one ranging terminal; the first network element determining a ranging start source terminal, where the ranging start source terminal is one of the at least one ranging terminal and the ranging start source terminal meets a first requirement; and the first network element instructing the ranging start source terminal to start ranging.

[0006] In the above implementation, the distance measurement initiation terminal determined by the first network element satisfies the requirements (i.e., satisfies the first requirement), so an appropriate terminal can be selected from the distance measurement terminals as the distance measurement initiation terminal, and as a result, the distance measurement initiation terminal starts the distance measurement operation.

[0007] In a possible implementation, a first network element determines the distance measurement initiation terminal, which is one of at least one distance measurement terminal, and the distance measurement initiation terminal satisfies the first requirement, which includes the first network element determining the first terminal as the distance measurement initiation terminal, where information about the first terminal exists in the first network element, and the first terminal is one of at least one distance measurement terminal.

[0008] In the above implementation, information about the terminal that initiated the distance measurement (in this case, the first terminal) is present in the first network element, thus reducing network interaction.

[0009] For example, the first network element is the LMF of the positioning request terminal (referred to here as the first LMF). The ranging terminals include the first terminal and the second terminal. Information about the first terminal (e.g., context information) resides in the first LMF, while information about the second terminal does not reside in the first LMF. In this case, the first LMF selects the first terminal as the ranging initiation terminal, and as a result, the first LMF can send a positioning request (or location request or ranging request) to the first terminal, instructing the first terminal to begin the ranging operation. However, in the same scenario, if the first LMF selects the second terminal as the ranging initiation terminal, the first LMF must send a positioning request (or location request or ranging request) to the second terminal's LMF (referred to as the second LMF), which then sends a request to the second terminal, instructing the second terminal to begin the ranging operation. It can be seen that network interaction can be reduced by selecting the first terminal as the distance measurement initiation terminal compared to selecting the second terminal as the distance measurement initiation terminal.

[0010] In another example, the first network element is the serving AMF of the positioning request terminal (referred to here as the first AMF). The ranging terminal includes the first and second terminals, with information about the first terminal (e.g., context information) residing in the first AMF, and information about the second terminal not residing in the first AMF. In this case, the first AMF selects the first terminal as the terminal from which ranging is initiated. Since the first AMF contains information about the first terminal, it transmits a positioning request (or location request or ranging request) to the positioning request terminal's LMF for the first terminal, and the positioning request terminal's LMF (referred to here as the first LMF) indicates that it has established context information for the first terminal. Thus, after the first AMF transmits the positioning request (or location request or ranging request) to the first LMF, the first LMF may transmit a request to the first terminal, instructing the first terminal to begin ranging operations. However, in the same scenario, if the first AMF selects the second terminal as the starting terminal for ranging, after the first AMF sends a positioning request (or location request) to the first LMF, the first LMF does not have context information for the second terminal. Therefore, the first LMF needs to send a positioning request (or location request or ranging request) to the second terminal's LMF (referred to here as the second LMF). The second LMF then sends the request to the second terminal, asking it to start ranging. It can be seen that selecting the first terminal as the starting terminal for ranging reduces network interaction compared to selecting the second terminal as the starting terminal for ranging.

[0011] In a possible implementation, the first network element is the first LMF; the first network element determines the starting terminal for distance measurement, where the starting terminal is one of at least one distance measurement terminal, and the starting terminal satisfies the first requirement, which includes, if the first LMF does not have information about any one of the at least one distance measurement terminal, the first LMF determines the second terminal as the starting terminal for distance measurement, where the second terminal is one of at least one distance measurement terminal.

[0012] In a possible implementation, the determination of the second terminal as the starting terminal for ranging by the first LMF includes: the first LMF obtaining identifiers for the Serving Access and Mobility Management Function AMF of at least one ranging terminal from the Integrated Data Management UDM; the first LMF obtaining one or more candidate LMFs for at least one ranging terminal from the Network Repository Function NRF based on the identifiers for the Serving AMF of at least one ranging terminal; and, if one or more candidate LMFs for the second terminal include the first LMF, the first LMF being determined to be usable as the LMF for the second terminal, and the second terminal being determined as the starting terminal for ranging.

[0013] In the above implementation, since one or more candidate LMFs of the second terminal include the first LMF, the first LMF can select the second terminal as the distance measurement initiation terminal, and as a result, the first LMF can send a request to the second terminal to request the second terminal to start the distance measurement operation. If one or more candidate LMFs of the distance measurement initiation terminal selected by the first LMF do not include the first LMF, the first LMF must instruct the distance measurement initiation terminal to start the distance measurement operation by using another network element (e.g., the distance measurement initiation terminal's LMF). It can be seen that selecting the second terminal as the distance measurement initiation terminal reduces network interaction compared to selecting another terminal as the distance measurement initiation terminal.

[0014] In a possible implementation, the first LMF obtaining one or more candidate LMFs of at least one ranging terminal from the NRF based on the identifier of the serving AMF of at least one ranging terminal includes: the first LMF sending a first query request to the NRF, the first query request holding the identifier of the serving AMF of at least one ranging terminal; and the first LMF receiving a first query response sent by the NRF, the first query response holding the identifier of one or more candidate LMFs of at least one ranging terminal.

[0015] Optionally, the first query request also retains registration area information for at least one ranging terminal.

[0016] Optionally, the first LMF obtaining one or more candidate LMFs for at least one ranging terminal from the NRF based on the identifier of the serving AMF of at least one ranging terminal includes: the first LMF sending at least one first query request to the NRF, where at least one first query request has a one-to-one correspondence with at least one ranging terminal, and each first query request holds the identifier of the serving AMF of the corresponding ranging terminal; and the first LMF receiving at least one first query response sent by the NRF, where at least one first query response has a one-to-one correspondence with at least one ranging terminal, and each first query response holds the identifiers of one or more candidate LMFs of the corresponding ranging terminal.

[0017] Optionally, each first query request further retains the registration area information of the corresponding ranging terminal.

[0018] In a possible implementation, the determination of the second terminal as the starting terminal for ranging by the first LMF includes: the first LMF obtaining the identifier of the serving AMF of at least one ranging terminal from the UDM; the first LMF obtaining first information from the NRF based on the identifier of the serving AMF of at least one ranging terminal, wherein the first information indicates that the first LMF can be used as the LMF of the second terminal; and the first LMF determining the second terminal as the starting terminal for ranging based on the first information.

[0019] In a possible implementation, the acquisition of first information from the NRF by the first LMF based on the identifier of the serving AMF of at least one ranging terminal includes: the first LMF sending a second query request to the NRF, the second query request holding the identifier of the serving AMF of at least one ranging terminal; and the first LMF receiving a second query response sent by the NRF, the second query response holding the first information.

[0020] In a possible implementation, the second query request holds an identifier or first instruction information for the first LMF, the identifier or first instruction information for the first LMF indicating that: if there is at least one ranging terminal that satisfies the first condition, the first LMF can be used as the LMF for the ranging terminal that satisfies the first condition, and the first information is returned, where one or more candidate LMFs for the ranging terminal that satisfies the first condition include the first LMF, and the ranging terminal that satisfies the first condition includes the second terminal.

[0021] Optionally, the second query response also retains the identifier of the first LMF.

[0022] Optionally, the second query request also retains registration area information for at least one additional ranging terminal.

[0023] Optionally, the acquisition of first information by the first LMF from the NRF based on the identifier of the serving AMF of at least one ranging terminal includes: the first LMF sending at least one second query request to the NRF, where at least one second query request has a one-to-one correspondence with at least one ranging terminal, and each second query request holds the identifier of the serving AMF of the corresponding ranging terminal; and the first LMF receiving at least one second query response sent by the NRF, where at least one second query response has a one-to-one correspondence with at least one ranging terminal, and each second query response holds an acknowledgment, which indicates whether the first LMF can be used as the LMF of the corresponding ranging terminal.

[0024] Optionally, each second query request further retains the registration area information of the corresponding ranging terminal.

[0025] In a possible implementation, for the first LMF to obtain the identifier of the serving AMF of at least one ranging terminal from the UDM: the first LMF sends a third query request to the UDM, where the third query request holds the identifier of at least one ranging terminal, and the first LMF receives the third query response sent by the UMD, where the third query response holds the identifier of the serving AMF of at least one ranging terminal.

[0026] Optionally, the third query response further holds the registration area information of at least one ranging terminal.

[0027] Optionally, for the first LMF to obtain the identifier of the serving AMF of at least one ranging terminal from the UDM: the first LMF sends at least one third query request to the UDM, where at least one third query request has a one-to-one correspondence with at least one ranging terminal, and each third query request holds the identifier of the corresponding ranging terminal; and the first LMF receives at least one third query response sent by the UDM, where at least one third query response has a one-to-one correspondence with at least one ranging terminal, and each third query response holds the identifier of the serving AMF of the corresponding ranging terminal.

[0028] Optionally, each third query response further holds the registration area information of the corresponding ranging terminal.

[0029] In a possible implementation, the first network element is the first AMF; for the first network element to determine the ranging start source terminal, where the ranging start source terminal is one of at least one ranging terminal and the ranging start source terminal meets the first requirement: if there is no information about any one of at least one ranging terminal in the first AMF, the first AMF determines the third terminal as the ranging start source terminal, where the third terminal is one of at least one ranging terminal.

[0030] In a possible implementation, the determination by the first AMF that the third terminal is the ranging start source terminal includes: the first AMF obtaining, from the UDM, the identifier of the serving AMF of at least one ranging terminal; the first AMF obtaining, from the NRF, one or more candidate LMFs of at least one ranging terminal based on the identifier of the serving AMF of at least one ranging terminal; and determining that the third terminal is the ranging start source terminal when one or more candidate LMFs of the third terminal include the LMF of the positioning request terminal. Alternatively, the determination by the first AMF that the third terminal is the ranging start source terminal includes: the first AMF obtaining, from the UDM, the identifier of the serving AMF of at least one ranging terminal; the first AMF obtaining, from the NRF, one or more candidate LMFs of at least one ranging terminal and one or more candidate LMFs of the positioning request terminal based on the identifier of the serving AMF of at least one ranging terminal and the identifier of the serving AMF of the positioning request terminal, where the serving AMF of the positioning request terminal is the first AMF; and determining that the third terminal is the ranging start source terminal when there is an intersection between one or more candidate LMFs of the third terminal and one or more candidate LMFs of the positioning request terminal.

[0031] When the first AMF selects an LMF for the positioning request terminal, one or more candidate LMFs of the third terminal used as the ranging start source terminal include the LMF selected by the first AMF. In other words, since the LMF can serve the third terminal, the LMF may send a request to the third terminal used as the ranging start source terminal and request to start the ranging operation, thereby reducing network interaction.

[0032] If the first AMF does not select an LMF, one or more candidate LMFs for the third terminal to be used as the ranging source terminal, and one or more candidate LMFs for the positioning request terminal, have a common area. Thus, the first AMF can select an LMF for the positioning request terminal from the LMFs in the common area, and the selected LMF can also be served to the third terminal. Therefore, the LMF can send a request to the third terminal to be used as the ranging source terminal, requesting it to start ranging operations, thereby reducing network interaction.

[0033] In a possible implementation, the first AMF obtaining one or more candidate LMFs of at least one ranging terminal from the NRF based on the identifier of the serving AMF of at least one ranging terminal includes: the first LMF sending a fourth query request to the NRF, the fourth query request holding the identifier of the serving AMF of at least one ranging terminal; and the first LMF receiving a first query response sent by the NRF, the first query response holding the identifier of one or more candidate LMFs of at least one ranging terminal.

[0034] Optionally, the fourth query request further retains registration area information for at least one ranging terminal.

[0035] Optionally, the operation of a first AMF based on the identifier of a serving AMF of at least one ranging terminal may include: the first AMF sending at least one fourth query request to the NRF, where at least one fourth query request has a one-to-one correspondence with at least one ranging terminal, and each fourth query request holds the identifier of the serving AMF of the corresponding ranging terminal; and the first AMF receiving at least one fourth query response sent by the NRF, where at least one fourth query response has a one-to-one correspondence with at least one ranging terminal, and each first query response holds the identifier of one or more candidate LMFs of the corresponding ranging terminal.

[0036] Optionally, each fourth query request further retains the registration area information of the corresponding ranging terminal.

[0037] In a possible implementation, the first AMF determining the third terminal as the starting terminal for ranging includes: the first AMF obtaining the identifier of the serving AMF of at least one ranging terminal from the UDM; the first AMF obtaining second information from the NRF based on the identifier of the serving AMF of at least one ranging terminal, wherein the second information indicates that one or more candidate LMFs of the third terminal include the LMF of the positioning request terminal; and the first AMF determining the third terminal as the starting terminal for ranging based on the second information. Alternatively, the first AMF determining the third terminal as the starting terminal for ranging includes: the first AMF obtaining the identifier of the serving AMF of at least one ranging terminal from the UDM; the first AMF obtaining second information from the NRF based on the identifier of the serving AMF of at least one ranging terminal and the identifier of the serving AMF of the positioning request terminal, wherein the second information indicates that one or more candidate LMFs of the third terminal and one or more candidate LMFs of the positioning request terminal have a common part, and the serving AMF of the positioning request terminal is the first AMF; and the first AMF determining the third terminal as the starting terminal for ranging based on the second information.

[0038] In a possible implementation, the acquisition of second information from the NRF by the first AMF based on the identifier of the serving AMF of at least one ranging terminal includes: the first AMF sending a fifth query request to the NRF, where the fifth query request holds at least the identifier of the serving AMF of at least one ranging terminal; and the first AMF receiving a fifth query response sent by the NRF, where the fifth query response holds the second information.

[0039] In a possible implementation, the fifth query request holds an AMF identifier or second instruction information, the first AMF identifier or second instruction information indicates that: the second information is returned if at least one ranging terminal satisfies the second condition, where one or more candidate LMFs of ranging terminals satisfying the second condition and one or more candidate LMFs of positioning request terminals have a common part; or one or more candidate LMFs of ranging terminals satisfying the second condition include the LMF of positioning request terminals, where ranging terminals satisfying the second condition include a third terminal.

[0040] Optionally, the fifth query response may also retain the identifier of the first AMF.

[0041] Optionally, the fifth query request further retains registration area information for at least one ranging terminal.

[0042] Optionally, the first AMF obtaining second information from the NRF based on the identifier of the serving AMF of at least one ranging terminal and the identifier of the first AMF includes: the first AMF sending at least one fifth query request to the NRF, where at least one fifth query request has a one-to-one correspondence with at least one ranging terminal, and each fifth query request holds the identifier of the serving AMF of the corresponding ranging terminal; and the first AMF receiving at least one fifth query response sent by the NRF, where at least one fifth query response has a one-to-one correspondence with at least one ranging terminal, and each fifth query response holds an acknowledgment, which indicates whether one or more candidate LMFs of the corresponding ranging terminal and one or more candidate LMFs corresponding to the first AMF have common parts.

[0043] Optionally, each fifth query request further retains the registration area information of the corresponding ranging terminal.

[0044] In a possible implementation, obtaining the identifier of the serving AMF of at least one ranging terminal from the UDM by the first AMF includes: the first AMF sending a sixth query request to the UDM, the sixth query request containing the identifier of at least one ranging terminal; and the first AMF receiving a sixth query response sent by the UDM, the sixth query response containing the identifier of the serving AMF of at least one ranging terminal.

[0045] Optionally, the sixth query response further retains registration area information for at least one ranging terminal.

[0046] Optionally, the first AMF obtaining the identifier of the serving AMF of at least one ranging terminal from the UDM includes: the first AMF sending at least one sixth query request to the UDM, where at least one sixth query request has a one-to-one correspondence with at least one ranging terminal, and each sixth query request holds the identifier of the corresponding ranging terminal; and the first AMF receiving at least one sixth query response sent by the UDM, where at least one sixth query response has a one-to-one correspondence with at least one ranging terminal, and each sixth query response holds the identifier of the serving AMF of the corresponding ranging terminal.

[0047] Optionally, each sixth query response further retains the registration area information of the corresponding ranging terminal.

[0048] In a possible implementation, the first network element is the first AMF, and the first network element instructing the distance measurement initiating terminal to begin distance measurement includes: the first AMF sending a second request to the second LMF, where the second request holds the instruction information of the distance measurement initiating terminal.

[0049] Optionally, the first network element is the first AMF, and the first network element instructing the ranging source terminal to begin ranging includes the first AMF sending a third request to the first gateway mobile location center (GMLC), where the third request holds the instruction information of the ranging source terminal. Optionally, the first GMLC is the GMLC corresponding to the ranging source terminal.

[0050] Optionally, the first network element is the first AMF; if at least one ranging terminal does not include a ranging terminal that satisfies the first requirement, the method further comprises: the first AMF determining a fourth terminal as the ranging initiator terminal, where the fourth terminal is any one of the at least one ranging terminal; the first AMF obtaining the identifier of the fourth terminal's serving AMF from the UDM; and the first AMF sending a fourth request to the fourth terminal's serving AMF based on the identifier of the fourth terminal's serving AMF, where the fourth request holds a notification that the fourth terminal is the ranging initiator terminal.

[0051] In a possible implementation, the first network element is the first GMLC. The method comprises: the first GMLC receiving a first position request, which is used to request that positioning be performed based on at least one ranging terminal; the first GMLC selecting a fifth terminal from at least one ranging terminal based on the reachability of the at least one ranging terminal; and the first GMLC transmitting a second position request to the first AMF, which holds first information indicating that the fifth terminal is a ranging initiator terminal, and the first AMF is the serving AMF of the fifth terminal.

[0052] Optionally, the first GMLC is the GMLC of the positioning request terminal.

[0053] Optionally, the reception of a first position request by the first GMLC includes the first GMLC receiving the first position request from the serving AMF of a positioning request terminal, wherein the first position request holds an identifier of at least one ranging terminal.

[0054] In another embodiment, a communication device is provided that includes one or more processors. One or more memories store one or more computer programs. One or more computer programs include instructions. When the instructions are executed by one or more processors, the communication device can perform a method according to any possible implementation of the first embodiment.

[0055] In another embodiment, a computer-readable storage medium comprising a computer program is further provided. When the computer program is executed on an electronic device, the electronic device is capable of performing the method according to any possible implementation of the first embodiment.

[0056] In another embodiment, a computer program product is further provided. When the computer program product is executed on an electronic device, the electronic device is capable of performing the method according to any possible implementation of the first embodiment.

[0057] In another embodiment, a chip system is provided comprising memory configured to store computer programs and a processor. After the processor retrieves a computer program from memory and executes the computer program, the electronic device on which the chip system is installed can perform the method according to any possible implementation of the first embodiment. [Brief explanation of the drawing]

[0058] [Figure 1] This is a diagram of a reference point-based architecture for 5G non-roaming according to an embodiment of the present invention. [Figure 2] This is a diagram of a reference point-based architecture for 5G non-roaming according to an embodiment of the present invention. [Figure 3] This is a diagram showing a positioning system architecture based on a 5G system according to an embodiment of the present invention. [Figure 4]This is a diagram showing the positioning procedure according to an embodiment of the present invention. [Figure 5] This is a block diagram of the positioning procedure implemented on the first network element side according to the embodiment of the present invention. [Figure 6] This figure shows the information exchange of the procedure and the positioning procedure based on the first network element according to an embodiment of the present invention. [Figure 7A] This is a diagram of the interaction procedure in the first example according to an embodiment of the present application. [Figure 7B] This is a diagram of the interaction procedure in the first example according to an embodiment of the present application. [Figure 7C] This is a diagram of the interaction procedure in the first example according to an embodiment of the present application. [Figure 8A] This is a diagram of the interaction procedure in the second example according to the embodiment of the present application. [Figure 8B] This is a diagram of the interaction procedure in the second example according to the embodiment of the present application. [Figure 8C] This is a diagram of the interaction procedure in the second example according to the embodiment of the present application. [Figure 9] This is a diagram of the interaction procedure in the third example according to the embodiment of the present application. [Figure 10] This is a diagram of the interaction procedure in the fourth example according to the embodiment of the present application. [Figure 11] This is a diagram of the interaction procedure in the fifth example according to the embodiment of the present application. [Figure 12] This is a diagram showing the structure of a communication device according to an embodiment of the present invention. [Figure 13] This is a diagram showing the structure of a communication device according to another embodiment of the present application. [Modes for carrying out the invention]

[0059] The technical solutions in the embodiments of this application will be described clearly and completely below with reference to the accompanying drawings. The terms used in the embodiments below are intended to describe specific embodiments only and are not intended to limit this application. The singular terms “one,” “a,” and “this” used in this specification and the attached claims are also intended to include expressions such as “one or more,” unless otherwise clearly defined in context. In the embodiments of this application, “one or more” means one, two, or more, and “and / or” describes a relationship between related subjects, indicating that three relationships may exist. For example, A and / or B may indicate the following cases: only A exists, both A and B exist, and only B exists, where A and B may be singular or plural. The symbol “ / ” generally indicates an “or” relationship between related subjects.

[0060] Any reference in this specification to “embodiments,” “some embodiments,” or similar means that one or more embodiments of the Application include certain features, structures, or characteristics described by reference to the embodiments. Accordingly, the phrases “in some embodiments,” “in some other embodiments,” and similar terms in various places in this specification do not necessarily all refer to the same embodiments, but mean “one or more embodiments, but not all.” The terms “equipment,” “includes,” “have,” and their derivatives all mean “includes, but not limited to,” unless otherwise specifically emphasized.

[0061] In the embodiments of this application, “multiple” refers to two or more. It should be noted that in the description of the embodiments of this application, terms such as “first” and “second” are intended merely as distinctions in the description and should not be interpreted as indicating or suggesting relative importance or order.

[0062] Figures 1 and 2 show a 5G non-roaming reference point-based architecture according to embodiments of the present invention. The 5G system architecture is divided into two parts: the access network and the core network. As shown in Figure 1, the network functions and entities in the network structure mainly include: user equipment (UE), (radio) access network ((R)AN), user plane network element (UPF), data network (DN), access and mobility management network element (AMF), session management network element (SMF), policy control network element (PCF), application function (AF), network slice selection function (NSSF), authentication server function (AUSF), unified data repository (UDR) function, and similar. Figure 2 shows the corresponding interfaces and interaction relationships between network functions and entities. For example, UE and AMF can interact with each other through the N1 interface, and interaction messages are called N1 messages. Some interfaces are implemented as service-oriented interfaces.

[0063] UE, (R)AN, UPF, and DN are generally referred to as data plane network function entities. User data traffic can be transmitted using packet data unit sessions (PDU sessions) established between the UE and DN, and transmission passes through two network function entities: (R)AN and UPF. The other part is referred to as the control plane network function entity, and is mainly responsible for functions such as authentication and authorization, registration management, session management, mobility management, and policy control, implementing reliable and stable transmission of user layer traffic. The user plane is used to carry service data, and the control plane is used to carry signaling messages.

[0064] Based on the above-described service-based 5G system architecture and non-roaming reference point-based architecture, the functions of the network elements related to this application are as follows:

[0065] Terminal devices: Terminal devices may be UEs, handheld terminals, notebook computers, subscriber units, cellular phones, smartphones, wireless data cards, personal digital assistant (PDA) computers, tablet computers, wireless modems, handheld devices, augmented reality (AR) devices, virtual reality (VR) devices, laptop computers, cordless phones or wireless local loop (WLL) stations, machine type communication (MTC) terminals, or other devices that can access the network. Terminal devices and access network devices communicate with each other using air interface technology (e.g., new radio (NR) or long-term evolution (LTE) technology). Terminal devices may also communicate with each other using air interface technology (e.g., NR technology or LTE technology). In Internet of Vehicle communications, a communication terminal mounted on a vehicle is a terminal device, and a roadside unit (RSU) can also be used as a terminal device. A communication terminal mounted on a drone can also be considered a terminal device.

[0066] (R)AN devices: (R)AN devices are devices that provide access for terminal devices, and include RAN devices and AN devices. RAN devices are primarily 3GPP® network radio network devices, while AN devices may be access network devices as defined in non-3GPP contexts. Radio access network (RAN) devices primarily perform functions such as radio resource management, quality of service (QoS) management, and data compression and encryption on the air interface side. RAN devices may include various forms of base stations, such as macro base stations, micro base stations (also called small cells), relay stations, and access points. In systems using different radio access technologies, devices with base station functionality may have different names. For example, a device may be called RAN or gNB (5G NodeB) in 5th generation (5G) systems, evolved NodeB (eNB or eNodeB) in LTE systems, and NodeB in 3rd generation (3G) systems.

[0067] Access network devices: These network elements enable interconnection and interaction between terminal devices and the 3GPP core network by using non-3GPP technologies. Examples of non-3GPP technologies include Wireless Fidelity (Wi-Fi®), Worldwide Interoperability for Microwave Access (WiMAX®), or Code Division Multiple Access (CDMA) networks.

[0068] AMF Network Elements: AMF network elements are core network elements and are primarily responsible for signaling processes, such as access control, mobility management, attachment and detachment, and gateway selection. When providing services for a session on a terminal device, AMF network elements provide control plane storage resources for the session to store a session identifier, an SMF network element identifier associated with the session identifier, and similar information.

[0069] SMF network elements: SMF network elements are primarily responsible for session management in mobile networks, such as user plane network element selection, user plane network element redirection, Internet Protocol (IP) address assignment, bearer establishment, modification and release, and QoS control.

[0070] UPF Network Elements: UPF network elements are responsible for the transfer and reception of user data at terminal devices. UPF network elements can receive user data from the data network and transmit it to terminal devices via access network devices. Furthermore, UPF network elements can receive user data from terminal devices via access network devices and transfer it to the data network. The transmission resources and scheduling functions used by UPF network elements to provide services to terminal devices are managed and controlled by SMF network elements.

[0071] PCF network elements: PCF network elements are primarily responsible for providing policy control decisions, providing policy rules for controlling plane functions, and providing traffic-based billing control functions.

[0072] Network exposure function (NEF) network element: The network exposure function network element primarily supports secure interaction between 3GPP networks and third-party applications.

[0073] AF Network Elements: AF network elements primarily support interacting with the 3GPP core network to provide services, for example, by influencing data routing decisions and policy control functions, or by providing several third-party services to the network side. When AF and 5G systems are in different trust domains, input may be provided through the NEF application programming interface (API). When AF and 5G systems are in the same trust domain, input may be provided directly by using the Time Sensitive Communication Time Synchronization function (TSCTSF). In 5G, application function network elements may be AF network elements as shown in Figure 1 or Figure 2, for example. In future communications, such as 6G, application function network elements may still be AF network elements or may have a different name. This is not limited to the present invention.

[0074] Unified Data Management (UDM) Network Element: The Unified Data Management (UDM) network element is configured to generate authentication certificates, process user identifiers (e.g., store and manage the user's permanent identity), control access authorization, and manage subscription data, among other things.

[0075] DN: DN is a serving network that provides data transmission services to users, such as IP multimedia services (IMS) or the Internet.

[0076] NSSF Network Elements: NSSF network elements are primarily responsible for selecting network slices and determining which instances of network slices are accessible by the UE based on the UE's slice selection aids, subscription information, and similar data.

[0077] AUSF Network Element: The AUSF network element supports authentication for 3GPP access and non-3GPP access.

[0078] Network repository function (NRF) network element: The network repository function network element supports the registration and discovery of network functions.

[0079] UDR network element: The UDR network element stores and retrieves subscription data used by UDM and PCF.

[0080] The Network Data Analytics Function (NWDAF) is a network element that supports collecting data from other network functions and AFs, collecting data from operations, administration and maintenance (OAM), and providing analytical information to other network functions and AFs.

[0081] In the architecture described above, each network element in the core network may also be referred to as a functional entity, device, or network function, and may be a network element implemented on dedicated hardware, a software instance running on dedicated hardware, or an instance of virtualization functionality on an appropriate platform. For example, the virtualization platform may be a cloud platform.

[0082] In this application, network elements may also be referred to as network functions, features, entities, or similar entities, but are not limited to this application.

[0083] The distribution configuration of network elements is not limited to the embodiments of this application. The distribution configuration shown in Figure 1 is merely an example and is not limited in this application. The communication system architecture shown in Figure 1 or Figure 2 is not limited to including only the network elements shown in the figures, and may further include other devices not shown in the figures. Details of each are not described here in this application.

[0084] For the sake of clarity, the network elements shown in Figure 1 are used later in this application as illustrative examples, and the XX network elements are simply referred to as XX. It should be understood that all network element names in the embodiments of this application are used merely as examples and may be referred to by other names in future communications, or that network elements in the embodiments of this application may be replaced by other entities, devices, or similar entities with the same functionality in future communications. This is not limited to the embodiments of this application. A consolidated explanation is provided here, and further details are not described again below.

[0085] The communication systems shown in Figures 1 and 2 do not constitute any limitation on communication systems to which embodiments of the present invention may be applicable. The communication system architecture shown in Figures 1 and 2 is a 5G system architecture. Optionally, the methods in embodiments of the present invention are further applicable to various future communication systems such as 6G and other communication networks.

[0086] Figure 3 shows a positioning system architecture based on a 5G system (5GS) according to an embodiment of the present invention. The LCS location service architecture based on the 5GS architecture mainly includes the following network elements, network functions, or entities.

[0087] Location Management Function (LMF) Network Element: The Location Management Function network element is configured to calculate final position estimation information based on distance measurement information (also referred to as positioning measurement values) collected by UE and NG-RAN, and to manage the coordination and scheduling of positioning resources.

[0088] UDM: The UDM is configured to store a UE location privacy configuration profile that can instruct the UE whether to allow another client or AF to obtain the UE's location information.

[0089] NEF Network Elements: NEF network elements are configured to provide a method for accessing location-based services by using external / internal AFs or clients.

[0090] Gateway Mobile Location Center (GMLC): A Gateway Mobile Location Center is configured to provide a method for accessing location-based services using external / internal AF or clients and to perform billing.

[0091] RAN / UE: RAN / UE is configured to collect LMF positioning measurements or parameters and calculate position estimates.

[0092] AMF Network Elements: The AMF network elements are configured to manage the positioning of the target UE for all types of location requests.

[0093] Based on the positioning system architecture shown in Figure 3, Figure 4 shows an example of a currently used positioning procedure. The procedure may include the following steps:

[0094] Step 401: UE3 triggers a service request. UE3 is either an LCS service request terminal or a positioning request terminal.

[0095] Step 402: UE3 performs an uplink non-access stratum (NAS) transmission to the serving AMF, sending a distance measurement request or a service location (SL) request (referred to as an SL request below) to the AMF via uplink NAS transmission, and also sending the identifiers of UE1 and UE2 (UE1 ID and UE2 ID) to the AMF. UE1 and UE2 are distance measurement terminals.

[0096] Step 403: The AMF selects the target LMF.

[0097] Step 404: The AMF sends a ranging request or SL positioning request to the target LMF and sends the identifiers of UE1 and UE2 (UE1 ID and UE2 ID) to the target LMF.

[0098] Step 405: The target LMF selects UE2 as the source for initiating the ranging operation on the PC5 interface, that is, it selects UE2 as the ranging source terminal (source UE), and sends a ranging request or SL positioning request to UE2.

[0099] Step 406: Based on the received ranging request or SL positioning request, UE2 initiates ranging operations between UE1 and UE2.

[0100] Step 407: UE2 sends the SL measurement report to the target LMF, where the SL measurement report holds the ranging results.

[0101] Step 408: The target LMF determines the SL positioning result based on the ranging results.

[0102] Step 409: The target LMF returns the ranging response to the AMF, where the ranging response holds the SL positioning result.

[0103] Step 410: The AMF performs a downlink NAS transmission to the UE3 and sends the SL positioning results to the UE3 via the downlink NAS transmission.

[0104] In the procedure described above, there is currently no effective solution for how the LMF selects the starting terminal for ranging. A possible solution is to randomly select a terminal from UE1 and UE2 as the starting terminal for ranging. Since the serving AMF or LMF of the ranging terminals (UE1 and UE2) and the positioning request terminal (UE3) may be different, different AMFs or LMFs may exchange information, which could affect positioning efficiency.

[0105] Based on this, embodiments of the present application provide a positioning method and related devices capable of implementing the method. The method provided in embodiments of the present application may be applicable to the positioning system architecture shown in Figure 3, or to an advanced architecture of the positioning system architecture. According to some embodiments of the present application, an appropriate distance measurement initiation terminal may be selected to reduce interaction between network elements, thereby reducing complexity, reducing latency, and improving positioning efficiency.

[0106] Referring to the attached drawings, the method and apparatus provided in the embodiments of the present application will be described below.

[0107] Figure 5 is a block diagram of the positioning procedure implemented on the first network element side according to an embodiment of the present invention. Figure 6 is a diagram of the information exchange of the positioning procedure based on the first network element and procedure in Figure 5. As shown in Figures 5 and 6, the procedure may include the following steps.

[0108] S501: The first network element receives a first request, which is used to request that positioning be performed based on at least one ranging terminal.

[0109] Optionally, the first request may be an SL positioning request, a distance measurement request, a position request, or other signaling that can be used to implement a positioning or distance measurement request. This is not limited to the present embodiments of the Application.

[0110] Optionally, the first request may hold an identifier for the ranging terminal. Optionally, the first request may further hold an identifier for the positioning request terminal. There may be one or more ranging terminals, two or three ranging terminals, or any other number of ranging terminals. The ranging terminals and the positioning request terminals may be different terminals or the same terminal.

[0111] A ranging terminal can be understood as a target UE configured to perform SL ranging, and a positioning request terminal as a terminal that consumes LCS services.

[0112] In possible implementations, the first request may originate from a positioning request terminal. For example, the positioning request terminal sends the first request, which is transmitted to the first network element through the relevant network element (e.g., RAN, RAN's serving AMF, or the terminal's serving AMF).

[0113] In another possible implementation, the first request may alternatively originate from the AF. For example, the AF sends the first request, which reaches the first network element through the relevant network element. Optionally, the relevant network element may include the NEF and the GMLC of the positioning request terminal, and may further include the serving AMF of the positioning request terminal.

[0114] Optionally, if the first request is from AF, the first request may contain the identifier of the positioning requesting terminal.

[0115] Optionally, the first network element may be the serving AMF of the positioning request terminal, the LMF of the positioning request terminal, the GMLC of the positioning request terminal, or the NEF. The positioning procedure provided in the embodiments of the present application will be described below by using different network elements as the first network element.

[0116] In Figure 6, the second network element is used to represent the network element that originated the first request. As described above, the second network element may be one of the following network elements: UE, RAN, AMF, and GMLC. For example, when the first network element is LMF, the second network element is AMF; when the first network element is AMF, the second network element is RAN (or UE, e.g., UE sends the first request by using NAS messages), or GMLC; or when the first network element is GMLC, the second network element is NEF or AMF.

[0117] S502: The first network element determines the distance measurement initiation terminal, where the distance measurement initiation terminal is one of at least one distance measurement terminal, and the distance measurement initiation terminal satisfies the first requirement.

[0118] In a possible implementation, the first network element may determine the first terminal in at least one ranging terminal as the ranging initiation terminal, and the first terminal satisfies the following requirement: information about the first terminal exists in the first network element. Optionally, the information about the first terminal may include the first terminal's positioning context information or ranging context information. In other words, if information about the first terminal in a ranging terminal (the terminal's positioning context information or ranging context information) exists in the first network element, the first network element may determine the first terminal as the ranging initiation terminal.

[0119] In the scenario involving two ranging terminals (UE1 and UE2), if the AMF is UE1 initiating a ranging request to LMF3, LMF3 may be considered to have established a positioning context or ranging context for UE1.

[0120] For example, the first network element is the LMF of the positioning request terminal, which is represented as UE3. The distance measuring terminals include UE1 and UE2, and UE3's LMF is represented as LMF3. UE1's positioning context information resides in LMF3, while UE2's positioning context information does not reside in LMF3. If UE1 is selected as the distance measuring initiation terminal, LMF3 sends a distance measuring request or SL positioning request to UE1, requesting UE1 to perform the distance measuring operation, and can receive the distance measuring result returned by UE1. If UE2 is selected as the distance measuring initiation terminal, LMF3 must send a distance measuring request or SL positioning request to UE2's LMF (represented as LMF2). Next, LMF2 sends a distance measuring request or SL positioning request to UE2, requesting UE2 to perform the distance measuring operation, UE2 sends the distance measuring result to LMF2, and LMF2 sends the distance measuring result to LMF3. In addition, the interaction between LMF3 and LMF2 may need to pass through multiple intermediate network elements such as GMLC and AMF. Compared to selecting UE2 as the distance measurement initiation terminal, it can be seen that selecting UE1, which satisfies the first requirement in this embodiment of the present application, as the distance measurement initiation terminal reduces network interaction operations.

[0121] If information about multiple ranging terminals exists in the first network element at an optional level, the first network element may randomly select one of the multiple ranging terminals as the ranging initiation terminal, or it may perform the selection according to other criteria (e.g., according to terminal subscription information or UE reachability). This is not limited to the present embodiments of the Application.

[0122] In another example, the first network element is the serving AMF of the positioning request terminal, represented as UE3, the ranging terminals include UE1 and UE2, UE3's LMF is represented as LMF3, UE3's serving AMF is represented as AMF3, UE1's context information resides in AMF3, and UE2's positioning context information does not reside in AMF3. If AMF3 selects UE1 as the ranging initiation terminal, AMF3 contains UE1's positioning context information, which indicates that AMF3 has sent a positioning request (location request or ranging request) for UE1 to LMF3 and that positioning context information for UE1 has been established in LMF3. Thus, after AMF3 has sent a positioning request (or location request or ranging request) to LMF3, LMF3 may send a request to UE1 instructing the first terminal to begin ranging operations. However, in the same scenario, if AMF3 selects UE2 as the starting terminal for distance measurement, after AMF3 sends a positioning request (or location request or distance measurement request) to LMF3, LMF3 does not have positioning context information for UE2. Therefore, LMF3 needs to send the request to UE2's LMF (referred to here as LMF2), which then sends the request to UE2, instructing the second terminal to start the distance measurement operation. In addition, the interaction between LMF3 and LMF2 may need to pass through multiple intermediate network elements such as GMLC and AMF. Similarly, the above differences also exist regarding the transmission path of the distance measurement results. It can be seen that network interaction can be reduced by selecting UE1 as the starting terminal for distance measurement compared to selecting UE2.

[0123] In possible implementations, the first network element is the first LMF. Optionally, the first LMF is the LMF of the positioning request terminal. In this case, if information about any one of the at least one ranging terminals is not present in the first LMF, the first LMF identifies the second terminal of at least one ranging terminal as the ranging initiation terminal.

[0124] Optionally, the second terminal may meet the following requirements: the first LMF can be used as the second terminal's LMF. Optionally, if one or more candidate LMFs of the second terminal include the first LMF, the first LMF can be used as the second terminal's LMF. Because the first LMF can be used as the second terminal's LMF, network interaction operations can be reduced.

[0125] If multiple ranging terminals meet the above requirements, the first LMF may randomly select one of the multiple ranging terminals as the ranging initiation terminal, or it may perform the selection according to other criteria (e.g., according to terminal subscription information or UE reachability). This is not limited to the present embodiments of the Application.

[0126] In a possible implementation, the first LMF may interact with the UDM and NRF to obtain one or more candidate LMFs for the ranging terminals and, based on the one or more candidate LMFs for the ranging terminals, select the second terminal as the ranging source terminal. The process may include the following steps: the first LMF obtains the identifier of the serving AMF for each ranging terminal from the UDM and obtains one or more candidate LMFs for each ranging terminal from the NRF based on the identifier of the serving AMF for each ranging terminal; and, if one or more candidate LMFs for the second terminal include the first LMF, the first LMF is determined to be available as the LMF for the second terminal, and the first LMF determines the second terminal as the ranging source terminal.

[0127] Optionally, possible interaction processes between the first LMF and the NRF may include: the first LMF sending a first query request to the NRF, where the first query request holds an identifier for at least one serving AMF of a ranging terminal; and the NRF sending a first query response to the first LMF, where the first query response holds an identifier for one or more candidate LMFs of the ranging terminal. Optionally, the first query request further holds registration area information of the ranging terminal.

[0128] Optionally, another possible interaction process between the first LMF and the NRF may include: the first LMF sending N first query requests to the NRF (where N is an integer greater than or equal to 1, and N is the number of ranging terminals). The N first query requests have a one-to-one correspondence with the N ranging terminals, and each first query request holds the identifier of the serving AMF of the corresponding ranging terminal. For example, the first LMF sends a first query request to the NRF to query one or more identifiers of one or more candidate LMFs for ranging terminal 1; the first LMF sends a first query request to the NRF a second time to query one or more identifiers of one or more candidate LMFs for ranging terminal 2; the rest can be inferred by analogy. The NRF separately sends N first query responses. N first query responses have a one-to-one correspondence with N ranging terminals, and each first query response holds one or more identifiers of one or more candidate LMFs for the corresponding ranging terminal. Optionally, each first query request also holds registration area information for the corresponding ranging terminal.

[0129] In another possible implementation, the first LMF may, by interacting with the UDM and NRF, obtain one or more candidate LMFs for the ranging terminals and, based on the one or more candidate LMFs for the ranging terminals, select the second terminal as the ranging start terminal. The process may include the following steps: the first LMF obtains the identifier of the serving AMF for each ranging terminal from the UDM; obtains first information from the NRF based on the identifier of the serving AMF for each ranging terminal, where the first information indicates that the first LMF can be used as the LMF for the second terminal; and the first LMF confirms the second terminal as the ranging start terminal based on the first information. In the above process, the NRF may obtain one or more candidate LMFs for each ranging terminal based on the identifier of the serving AMF for each ranging terminal. If one or more candidate LMFs of the second terminal include the first LMF, the first information is transmitted to the first LMF, indicating that one or more candidate LMFs of the second terminal include the first LMF, or that the first LMF can be used as the LMF of the second terminal.

[0130] Optionally, the first information may include an identifier for the second terminal, or may include an identifier for the second terminal and directive information indicating that one or more candidate LMFs of the second terminal include the first LMF.

[0131] Optionally, the second query request may contain an identifier or first instruction information for the first LMF, the identifier or first instruction information for the first LMF indicating that: if a ranging terminal satisfying the first condition exists in the ranging terminals, the first message should be returned. One or more candidate LMFs of ranging terminals satisfying the first condition include the first LMF.

[0132] Optionally, possible interaction processes between the first LMF and the NRF may include: the first LMF sends a second query request to the NRF, where the second query request holds the identifier of the serving AMF of at least one ranging terminal; and the NRF sends a second query response to the first LMF, where the second query response holds the first information.

[0133] Optionally, the second query response may further retain the identifier of the first LMF.

[0134] Optionally, the second query request may also retain registration area information for the ranging terminal.

[0135] Optionally, another possible interaction process between the first LMF and the NRF may include: the first LMF sends N (where N is the number of ranging terminals) second query requests to the NRF, where the N second query requests correspond one-to-one with the N ranging terminals, and each second query request holds the identifier of the serving AMF of the corresponding ranging terminal; and the NRF sends N second query responses to the first LMF, where the N second query responses correspond one-to-one with the N ranging terminals, and each second query response holds an acknowledgment, which indicates whether the first LMF can be used as the LMF of the corresponding ranging terminal. Optionally, each second query request may further hold registration area information of the corresponding ranging terminal.

[0136] In a possible implementation, the process by which the first LMF interacts with the UDM to obtain the identifier of the serving AMF for the ranging terminal may include: the first LMF sends a third query request to the UDM, where the third query request contains the identifier of each ranging terminal; the UDM sends a third query response to the first LMF, where the third query response contains the identifier of the serving AMF for each ranging terminal. Optionally, the third query response may also contain registration area information for the ranging terminal.

[0137] In another possible implementation, the process by which the first LMF interacts with the UDM to obtain the identifier of the serving AMF of a ranging terminal may include: the first LMF sends N (where N is the number of ranging terminals) third query requests to the UDM, where the N third query requests correspond one-to-one with the N ranging terminals, and each third query request holds the identifier of the corresponding ranging terminal; and the UDM sends N third query responses to the first LMF, where the N third query responses correspond one-to-one with the N ranging terminals, and each third query response holds the identifier of the serving AMF of the corresponding ranging terminal. Optionally, each third query response may further hold registration area information of the corresponding ranging terminal.

[0138] In possible implementations, the first network element is the first AMF. Optionally, the first AMF is the serving AMF of the positioning request terminal. In this case, if the first AMF does not contain information about any one of at least one ranging terminal (e.g., positioning context information or ranging context information), the first AMF identifies a third terminal in at least one ranging terminal as the ranging initiation terminal.

[0139] Optionally, the third terminal must meet the following requirements.

[0140] When the first AMF selects the LMF of the positioning requesting terminal, one or more candidate LMFs of the third terminal include the LMF of the positioning requesting terminal.

[0141] Network interaction operations can be reduced by selecting a terminal that satisfies the above conditions as the starting terminal for distance measurement. For example, the positioning request terminal is represented as UE3, the distance measurement terminals include UE1 and UE2, the serving AMF of UE3 is represented as AMF3, AMF3 has selected the LMF of the positioning request terminal (represented as LMF3), one or more candidate LMFs of UE1 include LMF3, and one or more candidate LMFs of UE2 do not include LMF3. When AMF3 selects UE1 as the starting terminal for distance measurement, a distance measurement request, SL positioning request, or position request may be sent to LMF3, and as a result LMF3 sends a distance measurement request, SL positioning request, or position request to UE1 to request UE1 to perform the distance measurement operation and receives the distance measurement result returned by UE1. If AMF3 selects UE2 as the starting terminal for distance measurement, the distance measurement request, SL positioning request, or position request must be sent to UE2's serving AMF (represented as AMF2), and as a result, AMF2 sends the distance measurement request, SL positioning request, or position request to UE2's LMF (represented as LM2). Next, LMF2 sends the distance measurement request, SL positioning request, or position request to UE2, requesting UE2 to perform the distance measurement operation. UE2 sends the distance measurement result to LMF2, then LMF2 sends the distance measurement result to AMF3, and AMF3 sends the distance measurement result to LMF3. Compared to selecting UE2 as the starting terminal for distance measurement, it can be seen that network interaction operations can be reduced by selecting UE1, which satisfies the first requirement in this embodiment of the present application, as the starting terminal for distance measurement.

[0142] If multiple ranging terminals meet the above requirements, the first AMF may randomly select one of the multiple ranging terminals as the ranging initiation terminal, or it may perform the selection according to other criteria (e.g., according to terminal subscription information or UE reachability). This is not limited to the present embodiments of the Application.

[0143] When the first AMF does not select the LMF of the positioning request terminal, one or more candidate LMFs of the third terminal and one or more candidate LMFs of the positioning request terminal have a common part.

[0144] Since one or more candidate LMFs of the third terminal and one or more candidate LMFs of the positioning request terminal have a common part, the first AMF can select the same LMF for the positioning request terminal and the distance measurement initiation terminal (for example, by selecting an LMF from the common part), thereby reducing network interaction operations.

[0145] If multiple ranging terminals meet the above requirements, the first AMF may randomly select one of the multiple ranging terminals as the ranging initiation terminal, or it may perform the selection according to other criteria (e.g., according to terminal subscription information or UE reachability). This is not limited to the present embodiments of the Application.

[0146] In possible implementations, if the first AMF selects the LMF of a positioning request terminal, the first AMF may select the distance measurement initiation terminal in the following manner: The first AMF obtains the identifier of the serving AMF for each distance measurement terminal from the UDM, and based on the identifier of the serving AMF for each distance measurement terminal, obtains one or more candidate LMFs for each distance measurement terminal from the NRF; if one or more candidate LMFs for the third terminal include the LMF of the positioning request terminal selected by the first AMF, the first AMF confirms the third terminal as the distance measurement initiation terminal.

[0147] In another possible implementation, if the first AMF does not select the LMF of the positioning request terminal, the first AMF may select the distance measurement initiation terminal in the following manner: The first AMF obtains the identifier of the serving AMF of each distance measurement terminal from the UDM, and based on the identifier of the serving AMF of each distance measurement terminal and the identifier of the serving AMF of the positioning request terminal, obtains one or more candidate LMFs for each distance measurement terminal and one or more candidate LMFs for the positioning request terminal from the NRF (where the serving AMF of the positioning request terminal is the first AMF); and, if one or more candidate LMFs for the third terminal and one or more candidate LMFs for the positioning request terminal have a common part, the first AMF determines the third terminal as the distance measurement initiation terminal.

[0148] Optionally, a possible interaction process between the first AMF and NRF may include: the first LMF sends a fourth query request to the NRF, where the fourth query request holds identifiers for serving AMFs of N (where N is the number of ranging terminals); and the NRF sends a first query response to the first LMF, where the first query response holds identifiers for one or more candidate LMFs of the N ranging terminals. Optionally, the fourth query request may further hold registration area information for the ranging terminals.

[0149] Optionally, another possible interaction process between the first AMF and the NRF may include: the first AMF sends N fourth query requests to the NRF, where the N fourth query requests correspond one-to-one with N ranging terminals, and each fourth query request holds the identifier of the serving AMF of the corresponding ranging terminal; and the NRF sends N fourth query responses to the first AMF, where the N fourth query responses correspond one-to-one with N ranging terminals, and each first query response holds the identifier of one or more candidate LMFs of the corresponding ranging terminal. Optionally, each fourth query request may further hold registration area information of the corresponding ranging terminal.

[0150] In another possible implementation, if the first AMF selects the LMF of the positioning request terminal, the first AMF may select the distance measurement initiation terminal in the following manner: The first AMF obtains the identifier of the serving AMF of each distance measurement terminal from the UDM, and obtains second information from the NRF based on the identifier of the serving AMF of each distance measurement terminal, where the second information indicates that one or more candidate LMFs of the third terminal include the LMF of the positioning request terminal; and the first AMF confirms the third terminal as the distance measurement initiation terminal based on the second information.

[0151] In another possible implementation, if the first AMF does not select the LMF of the positioning request terminal, the first AMF may select the distance measurement initiation terminal in the following manner: The first AMF obtains the identifier of the serving AMF of each distance measurement terminal from the UDM, obtains second information from the NRF based on the identifier of the serving AMF of each distance measurement terminal and the identifier of the serving AMF of the positioning request terminal (where the serving AMF of the positioning request terminal is the first AMF), where the second information indicates that one or more candidate LMFs of the third terminal and one or more candidate LMFs of the positioning request terminal have a common part; and the first AMF determines the third terminal as the distance measurement initiation terminal based on the second information.

[0152] Optionally, possible interaction processes between the first AMF and the NRF may include: the first AMF sends a fifth query request to the NRF, where the fifth query request holds identifiers for at least N serving AMFs (where N is the number of ranging terminals); and the NRF sends a fifth query response to the first AMF, where the fifth query response holds the second information. Optionally, the fifth query response may further hold identifiers for the first LMF. Optionally, the fifth query request may further hold registration area information for the ranging terminals.

[0153] Optionally, the fifth query request may hold an identifier for the first AMF or second instruction information, the identifier for the first AMF or second instruction information indicating that: if a ranging terminal satisfying the second condition exists in the ranging terminals, the second information should be returned. One or more candidate LMFs of ranging terminals satisfying the second condition and one or more candidate LMFs of positioning request terminals have a common part, or one or more candidate LMFs of ranging terminals satisfying the second condition include the LMF of positioning request terminals.

[0154] Optionally, another possible interaction process between the first AMF and the NRF may include: the first AMF sends N (where N is the number of ranging terminals) fifth query requests to the NRF, where the N fifth query requests correspond one-to-one with N ranging terminals, and each fifth query request holds the identifier of the serving AMF of the corresponding ranging terminal, and optionally, the identifier of the first AMF; and the NRF sends N fifth query responses to the first AMF, where the N fifth query responses correspond one-to-one with at least one ranging terminal, and each fifth query response holds an acknowledgment, which indicates whether one or more candidate LMFs of the corresponding ranging terminal and one or more candidate LMFs corresponding to the first AMF have a common part. Optionally, each fifth query request may further hold registration area information of the corresponding ranging terminal.

[0155] In a possible implementation, the process by which the first AMF obtains the identifier of the serving AMF for at least one ranging terminal from the UDM may include: the first AMF sends a sixth query request to the UDM, which holds the identifiers of N ranging terminals (where N is the number of ranging terminals); and the UDM sends a sixth query response to the first AMF, which holds the identifiers of the serving AMFs for the N ranging terminals. Optionally, the sixth query response may further hold registration area information for the N ranging terminals.

[0156] In another possible implementation, the process by which the first AMF obtains the identifier of the serving AMF of at least one ranging terminal from the UDM may include: the first AMF sends N sixth query requests to the UDM, where the N sixth query requests correspond one-to-one with N ranging terminals, and each sixth query request holds the identifier of the corresponding ranging terminal; and the UDM sends N sixth query responses to the first AMF, where the N sixth query responses correspond one-to-one with at least one ranging terminal, and each sixth query response holds the identifier of the serving AMF of the corresponding ranging terminal. Optionally, each sixth query response may further hold registration area information of the corresponding ranging terminal.

[0157] In a possible implementation, the first network element may be the first GMLC. Optionally, the first GMLC is the GMLC of the positioning request terminal. In this case, the first GMLC receives a first request, which is used to request that positioning be performed based on at least one ranging terminal; the first GMLC selects a fifth terminal from at least one ranging terminal based on the reachability of that terminal; the first GMLC sends a second request to the first AMF (e.g., the serving AMF of the fifth terminal), which holds third information indicating that the fifth terminal is the ranging initiator terminal; as a result, the first AMF sends a request to the first terminal's LMF, which requests the fifth terminal to initiate ranging with another ranging terminal.

[0158] Optionally, the first GMLC may obtain UDM context information for the ranging terminal from the UDM, determine the reachability of the ranging terminal based on the UDM context information, and select the ranging initiation terminal based on the reachability of the ranging terminal. For example, the ranging terminals include UE1 and UE2. If UE1 is currently outside network coverage, the network cannot page UE1, and UE1 may be set to unreachable and stored in the UE's UDM context information. Similarly, if UE2 is currently within network coverage and the network can page UE2, UE2 is set to reachable and stored in the UE's UDM context information. In this case, UE1 is unreachable and UE2 is reachable.

[0159] Optionally, the process by which the first GMLC receives a first request may include the following: the first GMLC receives a first request from the serving AMF of the positioning request terminal, where the first request may contain an identifier of at least one ranging terminal. For example, the positioning request terminal sends a first location request to the first AMF (i.e., the serving AMF of the positioning request terminal). After receiving the first location request, the first AMF sends a second location request to the GMLC of the positioning request terminal (i.e., the first GMLC), where the second location request may contain information such as an identifier of a ranging terminal.

[0160] S503: The first network element instructs the distance measurement initiation terminal to start distance measurement.

[0161] In possible implementations, if the first network element is the first LMF (e.g., the LMF of the positioning request terminal), in S503, the first LMF may transmit a distance measurement request or an SL positioning request to the distance measurement initiation terminal, and as a result, the distance measurement initiation terminal initiates a distance measurement (ranging) operation among distance measurement terminals, for example, by initiating a distance measurement operation on the PC5 interface. The distance measurement initiation terminal obtains the distance measurement result based on the distance measurement operation and transmits the distance measurement result to the first LMF. Furthermore, the first LMF may transmit the distance measurement result to the distance measurement initiation terminal or AF (through the relevant network element).

[0162] In another possible implementation, if the first network element is the first AMF (e.g., the serving AMF of the positioning request terminal), in S503, the first AMF sends a second request to the first LMF (e.g., the LMF of the positioning request terminal), where the second request holds instruction information for the distance measurement initiation terminal. After receiving the second request, the first LMF sends a distance measurement request or SL positioning request to the distance measurement initiation terminal, and as a result, the distance measurement initiation terminal initiates a distance measurement (ranging) operation between terminals based on the distance measurement request or SL positioning request, for example, by initiating a distance measurement operation on the PC5 interface. The distance measurement initiation terminal obtains the distance measurement result based on the distance measurement operation and sends the distance measurement result to the first LMF. Furthermore, the first LMF may further send the distance measurement result to the distance measurement initiation terminal or AF (through the relevant network element).

[0163] Optionally, the distance measurement result may also be referred to as measurement information of the measurement result. Optionally, after receiving the measurement information, the LMF may further determine the measurement result (also referred to as the distance measurement result or positioning result) based on the measurement information, and further transmit the measurement result (also referred to as the distance measurement result or positioning result) to the positioning request terminal or AF.

[0164] In another possible implementation, if the first network element is the first GMLC, in S503, the first GMLC sends a position request to the serving AMF of the ranging-initiating terminal, where the position request holds the indicating information of the ranging-initiating terminal. The serving AMF of the ranging-initiating terminal sends a position request to the LMF of the ranging-initiating terminal, where the position request holds the indicating information of the ranging-initiating terminal. The LMF sends a ranging request or SL positioning request to the ranging-initiating terminal, as a result the ranging-initiating terminal starts ranging operations between ranging terminals, for example, starting ranging operations on the PC5 interface. The ranging-initiating terminal obtains ranging results based on the ranging operations and sends the ranging results to the LMF. Furthermore, the LMF may send the ranging results to the first GMLC, which then sends the ranging results to the ranging-initiating terminal or AF (through the relevant network element).

[0165] In another embodiment of the present application, if the first network element is a first AMF (e.g., a serving AMF for positioning requests) and there are no terminals among the ranging terminals that satisfy the first requirement (e.g., no context information for any ranging terminal is available in all first AMFs, or no context information for any ranging terminal is available in any first AMF, and the first AMF cannot select the same LMF for the positioning request terminal and the ranging initiation terminal (e.g., one or more candidate terminals of the positioning request terminal do not include one or more candidate LMFs of the ranging initiation terminal, or one or more candidate LMFs of the positioning request terminal and one or more candidate LMFs of the ranging initiation terminal have no common parts)), then the first AMF may select any one of the ranging terminals (e.g., a fourth terminal) as the ranging terminal. Next, a third request (e.g., a location request) may be transmitted to a first GMLC (i.e., the GMLC of the ranging initiation terminal), the third request holding instruction information for the ranging initiation terminal. After receiving the third request, the first GMLC transmits a position request to the LMF of the ranging-initiating terminal by using the ranging-initiating terminal's serving AMF. The LMF transmits a ranging request or SL positioning request to the ranging-initiating terminal. As a result, the ranging-initiating terminal initiates ranging operations, for example, by initiating ranging operations on the PC5 interface. The ranging-initiating terminal obtains ranging results based on the ranging operations and transmits the ranging results to the LMF. The LMF confirms the SL positioning results. Next, the LMF transmits the positioning results to the first GMLC by using the ranging-initiating terminal's serving AMF. Furthermore, the first GMLC may transmit the positioning results to the positioning requesting terminal or AF (through the relevant network elements).

[0166] In a possible implementation, if the first AMF randomly selects a terminal, for example, the fourth terminal, as the ranging terminal, the first AMF may obtain the identifier of the fourth terminal's serving AMF from the UDM and send a request (fourth request) to the fourth terminal's serving AMF based on the identifier of the fourth terminal's serving AMF, where the request holds instruction information indicating that the fourth terminal is the ranging initiation terminal. Next, the fourth terminal's serving AMF sends a positioning request to the fourth terminal's LMF, where the positioning request holds instruction information indicating that the fourth terminal is the ranging initiation terminal. The LMF sends a ranging request or SL positioning request to the fourth terminal serving as the ranging initiation terminal, and as a result, the ranging initiation terminal starts ranging operations between ranging terminals, for example, starting ranging operations on the PC5 interface. The ranging initiation terminal obtains ranging results based on the ranging operations and sends the ranging results to the LMF. The LMF determines the SL positioning result based on the ranging (ranging) results. Furthermore, the LMF may transmit the SL positioning result to the positioning request terminal or AF.

[0167] In the above implementation, the distance measurement initiation terminal determined by the first network element satisfies the requirements (i.e., satisfies the first requirement), so an appropriate terminal can be selected from the distance measurement terminals as the distance measurement initiation terminal, and as a result, the distance measurement initiation terminal starts the distance measurement operation.

[0168] Based on the above embodiment, Figures 7A, 7B, and 7C to 11 each show several examples of information exchange flowcharts. Below, the procedures shown in Figures 7A, 7B, and 7C to 11 will be described separately.

[0169] Figures 7A, 7B, and 7C illustrate the information exchange procedure in a first example according to an embodiment of the present invention. In the first example, the positioning request terminal is UE3, and the ranging terminals include UE1 and UE2. AMF1 is the serving AMF of UE1, AMF3 is the serving AMF of UE3, the LMF of UE1 is represented as LMF1, and the LMF of UE3 is represented as LMF3. The ranging request is transmitted transparently to LMF3 as a container. Since the container is invisible to the AMF, LMF3 selects the ranging initiation terminal. As shown in the figures, the procedure may include the following steps.

[0170] Step 701a: AF triggers the distance measurement requirement.

[0171] Optionally, the AF sends a position request to the AMF3 to request SL ranging services. The position request holds a container containing the identifiers of the ranging terminals UE1 and UE2 (UE1 ID and UE2 ID). Optionally, the position request may further hold the identifier of the positioning request terminal UE3 (UE3 ID). Furthermore, the container may further include information such as the SL ranging service type, measurement type, and SL ranging requirements.

[0172] Optionally, requests triggered by AF may be sent to AMF3 using NEF and GMLC3.

[0173] Step 701b: UE3 triggers the distance measurement requirement.

[0174] Optionally, UE3 sends a location request to AMF3 using NAS messages to request SL ranging services. The location request holds a container containing the identifiers of the ranging terminals UE1 and UE2 (UE1 ID and UE2 ID). Furthermore, the container may contain information such as the SL ranging service type, measurement type, and SL ranging requirements.

[0175] In a positioning scenario, generally only one of steps 701a and 701b is performed, i.e., the ranging requirement is triggered by either AF or UE3.

[0176] Step 702: AMF3 selects LMF3 for the positioning request terminal UE3.

[0177] Since positioning-related information is transmitted in container mode, the UE1 ID and UE2 ID are invisible to AMF3, and it is not possible to select the distance measurement initiation terminal from UE1 and UE2. Therefore, LMF selects the distance measurement initiation source terminal, and AMF3 selects LMF (for example, LMF3 in this example) for UE3.

[0178] Step 703: AMF3 sends a positioning request to LMF3, where the positioning request holds a container.

[0179] Step 704: LMF3 checks whether context information for UE1 or UE2 exists.

[0180] In this example, if the context information for UE1 exists in LMF3 but the context information for UE2 does not, step 705 is executed; or, if neither the context information for UE1 nor the context information for UE2 exists in LMF3, step 706 is executed.

[0181] Step 705: LMF3 selects UE1 as the starting terminal for distance measurement.

[0182] In this step, an example is used where the context information for UE1 exists in LMF3. If the context information for UE2 exists in LMF3 but the context information for UE1 does not, LMF3 selects UE2 as the starting terminal for distance measurement. If the context information for both UE1 and UE2 exists in LMF3, LMF3 may select either UE1 or UE2 as the starting terminal for distance measurement.

[0183] Step 706: Determine whether LMF3 can be used as the LMF for UE1 or UE2; if LMF3 can be used as the LMF for UE1, perform step 707, or if LMF3 cannot be used as the LMF for UE1, perform step 709.

[0184] In this step, LMF3 may interact with the NRF using the UDM to obtain candidate LMFs for UE1 and UE2, thereby determining whether LMF3 can be used as the LMF for UE1 or UE2 based on the candidate LMFs for UE1 and UE2. For example, the process may include steps 706a through 706e.

[0185] Step 706a: LMF3 sends a query request to UDM, where the query request may hold the UE1 ID and UE2 ID, and requests the identifiers of the serving AMFs for UE1 and UE2.

[0186] Step 706b: The UDM returns a query response to the LMF3, which may contain the identifier of the UE1 serving AMF (UE1 AMF ID) and the identifier of the UE2 serving AMF (UE2 AMF ID). Optionally, the query response may also contain registration area information for UE1 and UE2.

[0187] In the possible alternative solutions of steps 706a to 706b, LMF3 sends query request 1 to the UDM, which holds the identifier of UE1, and receives query response 1, which is returned by the UDM, which holds the identifier of the serving AMF for UE1. Optionally, query response 1 may further include registration area information for UE1. LMF3 sends query request 2 to the UDM, which holds the identifier of UE2, and receives query response 2, which is returned by the UDM, which holds the identifier of the serving AMF for UE2. Optionally, query response 2 may further include registration area information for UE2.

[0188] Step 706c: LMF3 sends a query request to NRF to request candidate LMFs for each ranging terminal. The query request may contain the UE1 AMF ID and UE2 AMF ID, as well as registration area information for UE1 and UE2, and information such as LMF type information.

[0189] Step 706d: NRF returns a query response to LMF3, where the query response may contain the identifiers of the candidate LMFs for UE1 and UE2. There may be one or more candidate LMFs.

[0190] In the possible alternative solutions of steps 706c to 706d, LMF3 sends query request 1 to the NRF, which holds the identifier of the serving AMF for UE1, and receives query response 1 from the NRF, which holds the identifier of a candidate LMF for UE1. Optionally, query request 1 may further include registration area information for UE1. LMF3 sends query request 2 to the NRF, which holds the identifier of the serving AMF for UE2, and receives query response 2 from the NRF, which holds the identifier of a candidate LMF for UE2. Optionally, query request 2 may further include registration area information for UE2.

[0191] In an alternative solution to steps 706c through 706d, LMF3 sends a query request to the NRF requesting that it determine whether LMF3 can serve UE1 or UE2, or whether LMF3 can be used as the LMF for UE1 or UE2. The query request may contain the UE1 AMF ID and the UE2 AMF ID, as well as registration area information for UE1 and UE2, and information such as LMF type information. The NRF returns a query response to LMF3, which includes the first information. If one or more candidate LMFs for UE1 include LMF3, the first information may contain the identifier for UE1 and optionally further include a confirmation instruction. After receiving the first information, LMF3 uses UE1 as the starting terminal for distance measurement. If one or more candidate LMFs for UE2 include LMF3, the first information may contain the identifier for UE2 and optionally further include a confirmation instruction. After receiving the first information, LMF3 uses UE2 as the starting terminal for distance measurement. If one or more candidate LMFs of UE1 and UE2 include LMF3, the first information may include identifiers of UE1 and UE2. After receiving the first information, LMF3 may use the corresponding distance measurement terminal as the starting terminal for distance measurement based on the identifier of the UE included in the first information.

[0192] In an alternative solution to steps 706c-706d, LMF3 sends query request 1 to the NRF, which holds the serving AMF for UE1. Optionally, query request 1 may further hold information such as registration area information and LMF type information for UE1. The NRF returns query response 1 to LMF3. Query response 1 includes first information indicating whether one or more candidate LMFs for UE1 include LMF3, or whether LMF3 can serve UE1. LMF3 sends query request 2 to the NRF, which holds the serving AMF for UE2. Optionally, query request 2 may further hold information such as registration area information and LMF type information for UE2. The NRF returns query response 2 to LMF3. Query response 2 includes first information indicating whether one or more candidate LMFs for UE2 include LMF3, or whether LMF3 can serve UE2.

[0193] Step 706e: LMF3 determines whether one or more candidate LMFs for UE1 or UE2 include LMF3; if one or more candidate LMFs for UE1 include LMF3, step 707 is performed, or if one or more candidate LMFs for UE1 do not include LMF3, step 709 is performed.

[0194] Note that when LMF3 receives the identifiers of candidate LMFs for UE1 and UE2, LMF3 will determine, based on the identifiers of the candidate LMFs for UE1 and UE2, whether one or more candidate LMFs for UE1 or UE2 include LMF3. When LMF3 receives the first information, LMF3 may directly determine, based on the first information, whether one or more candidate LMFs for UE1 or UE2 include LMF3.

[0195] Step 707: LMF3 selects UE1 as the starting terminal for distance measurement and proceeds to step 708.

[0196] In this step, we use an example where one or more candidate LMFs for UE1 include LMF3. If one or more candidate LMFs for UE2 include LMF3, LMF3 selects UE2 as the starting terminal for distance measurement. If candidate LMFs for both UE1 and UE2 include LMF3, LMF3 may select either UE1 or UE2 as the starting terminal for distance measurement.

[0197] Step 708: LMF3 initiates and performs the ranging operation between UE1 and UE2, and then proceeds to step 710.

[0198] This step may involve a multi-step information exchange process and may involve the serving AMF of UE1 and UE2.

[0199] Step 709: As the source of the distance measurement request, LMF3 instructs the distance measurement initiator terminal to perform the distance measurement operation by using GMLC, and then proceeds to step 710.

[0200] Optionally, step 709 may include steps 709a to 709e.

[0201] Step 709a: As a ranging request source, LMF3 sends a position request to UE1's serving AMF (AMF1) using GMLC3, where the position request may hold a container.

[0202] Step 709b: AMF1 initiates a range-measuring (ranging) positioning request for UE1 to LMF1 and requests the range-measuring (ranging) result between UE1 and UE2.

[0203] Step 709c: LMF1 begins performing ranging between UE1 and UE2. The process may involve LMF1, AMF1, UE1 and UE2, and optionally, RAN as well.

[0204] Step 709d: LMF1 returns the range measurement result to AMF1.

[0205] Step 709e: AMF1 returns the range measurement (ranging) result to LMF3 using GMLC1.

[0206] Step 710: LMF3 transmits a positioning response to AMF3, where the positioning response may contain the distance measurement result.

[0207] Step 711a: If the distance measurement is triggered by AF (see Step 701a), AMF3 transmits the distance measurement result to AF using GMLC3 and NEF.

[0208] Step 711b: If the distance measurement is triggered by UE3 (see Step 701b), AMF3 sends the distance measurement result to UE3. For example, the distance measurement result may be sent to UE3 using a downlink NAS message.

[0209] The above is illustrated by using three terminals as an example. In a two-terminal scenario, the LMF may also select the terminal that initiates the ranging process based on the principles of the procedure described above. In this scenario, LMF3 may select the terminal requesting positioning as the terminal that initiates the ranging process. In a scenario involving more than two ranging terminals, the LMF may also select the terminal that initiates the ranging process based on the principles of the procedure described above.

[0210] Figures 8A, 8B, and 8C illustrate the information exchange procedure in a second example according to an embodiment of the present invention. In the second example, the positioning request terminal is UE3, and the ranging terminals include UE1 and UE2. AMF1 is the serving AMF of UE1, AMF3 is the serving AMF of UE3, the LMF of UE1 is represented as LMF1, and the LMF of UE3 is represented as LMF3. Since the ranging requirement is visible to the AMF, the AMF selects the ranging initiation terminal. As shown in the figures, the procedure may include the following steps.

[0211] Step 801a: AF triggers the distance measurement requirement.

[0212] Optionally, AF sends a position request to AMF3 to request SL ranging service. The position request holds the identifiers of ranging terminals UE1 and UE2 (UE1 ID and UE2 ID), optionally further may hold the identifier of positioning request terminal UE3 (UE3 ID), and may further hold information such as the SL ranging service type, measurement type, and SL ranging requirement.

[0213] Optionally, requests triggered by AF may be sent to AMF3 using NEF and GMLC3.

[0214] Step 801b: UE3 triggers the distance measurement requirement.

[0215] Optionally, UE3 sends a location request to AMF3 using a NAS message to request SL ranging service. The location request may contain identifiers for ranging terminals UE1 and UE2 (UE1 ID and UE2 ID), and may also contain information such as the SL ranging service type, measurement type, and SL ranging requirement.

[0216] In a positioning scenario, generally only one of steps 801a and 801b is performed, i.e., the ranging requirement is triggered by either AF or UE3.

[0217] Step 802: AMF3 checks whether context information for UE1 or UE2 exists.

[0218] Since positioning-related information is not transmitted in container mode, it is visible to the AMF3. Therefore, the AMF3 can select the terminal that initiated the range measurement.

[0219] In this example, if context information for UE1 exists in AMF3 but context information for UE2 does not, step 803 is executed; or, if neither context information for UE1 nor context information for UE2 exists in AMF3, step 804 is executed.

[0220] Step 803: AMF3 selects UE1 as the starting terminal for range measurement.

[0221] In this step, an example is used where the context information for UE1 exists in AMF3. If the context information for UE2 exists in AMF3 but the context information for UE1 does not, AMF3 selects UE2 as the starting terminal for distance measurement. If the context information for both UE1 and UE2 exists in AMF3, AMF3 may select either UE1 or UE2 as the starting terminal for distance measurement.

[0222] Step 804: AMF3 determines whether the same LMF can be selected for UE3 and either UE1 or UE2. If the same LMF can be selected for UE3 and either UE1 or UE2, proceed to step 805; otherwise, proceed to step 807.

[0223] In this step, AMF3 may interact with NRF by using UDM to obtain candidate LMFs for UE1 and UE2, thereby determining whether AMF3 can select the same LMF for UE3 and for either UE1 or UE2 based on the candidate LMFs for UE1 and UE2. For example, the process may include steps 804a to 804e.

[0224] Step 804a: AMF3 sends a query request to UDM, where the query request may hold the UE1 ID and UE2 ID, and requests the identifiers of the serving AMFs for UE1 and UE2.

[0225] Step 804b: The UDM returns a query response to AMF3, which may contain the identifier of the serving AMF for UE1 (UE1 AMF ID) and the identifier of the serving AMF for UE2 (UE2 AMF ID). Optionally, the query response may also contain registration area information for UE1 and UE2.

[0226] In the possible alternative solutions of steps 804a to 804b, AMF3 sends query request 1 to the UDM, which holds the identifier of UE1, and receives query response 1, which is returned by the UDM, which holds the identifier of the serving AMF for UE1. Optionally, query response 1 may further include registration area information for UE1. AMF3 sends query request 2 to the UDM, which holds the identifier of UE2, and receives query response 2, which is returned by the UDM, which holds the identifier of the serving AMF for UE2. Optionally, query response 2 may further include registration area information for UE2.

[0227] Step 804c: AMF3 sends a query request to NRF to request candidate LMFs for each ranging terminal. The query request may contain the UE1 AMF ID and UE2 AMF ID, as well as registration area information for UE1 and UE2, and information such as LMF type information.

[0228] Step 804d: NRF returns a query response to AMF3, where the query response may contain the identifiers of candidate LMFs for UE1 and UE2. There may be one or more candidate LMFs.

[0229] In the possible alternative solutions of steps 804c to 804d, AMF3 sends query request 1 to the NRF, which holds the identifier of the serving AMF for UE1, and receives query response 1 from the NRF, which holds the identifier of the candidate LMF for UE1. Optionally, query request 1 may further include registration area information for UE1. AMF3 sends query request 2 to the NRF, which holds the identifier of the serving AMF for UE2, and receives query response 2 from the NRF, which holds the identifier of the candidate LMF for UE2. Optionally, query request 2 may further include registration area information for UE2.

[0230] In an alternative solution to steps 804c through 804d, AMF3 sends a query request to NRF requesting that AMF3 determine whether the same LMF can be selected for UE3 and the ranging source terminal. The query request may hold the UE1 AMF ID and UE2 AMF ID, an identifier for AMF3, registration area information for UE1 and registration area information for UE2, and information such as LMF type information. NRF returns a query response to AMF3, which includes second information. If one or more candidate LMFs for UE1 and one or more candidate LMFs for UE3 have common parts, the second information may include an identifier for UE1 and optionally further include a confirmation instruction. After receiving the second information, AMF3 uses UE1 as the ranging source terminal. If one or more candidate LMFs of UE2 and one or more candidate LMFs of UE3 have common parts, the second information may include an identifier for UE2 and optionally further include a confirmation instruction that MAF3 may use UE2 as the starting terminal for ranging after receiving the second information. If both candidate LMFs of UE1 and UE2 have common parts with one or more candidate LMFs of UE3, the second information may include an identifier for UE1 or UE2. After receiving the second information, LMF3 may use the corresponding ranging terminal as the starting terminal for ranging based on the identifier of the UE included in the second information.

[0231] Optionally, the AMF3 identifier in a query request is optional. In some scenarios, since the positioning request originates from AMF3, the LMF can by default recognize that the common part of the candidate LMFs of the ranging terminal and the positioning requesting terminal is being queried, and can automatically obtain the AMF3 ID.

[0232] In an alternative solution to steps 804c-804d, AMF3 sends query request 1 to NRF, which holds the serving AMF for UE1. Optionally, query request 1 may further hold information such as registration area information and LMF type information for UE1. NRF returns query response 1 to AMF3. Query response 1 includes second information indicating whether one or more candidate LMFs for UE1 and one or more candidate LMFs for UE3 have common parts. AMF3 sends query request 2 to NRF, which holds the serving AMF for UE1. Optionally, query request 2 may further hold information such as registration area information and LMF type information for UE2. NRF returns query response 2 to AMF3. Query response 2 includes first information indicating whether one or more candidate LMFs for UE2 and one or more candidate LMFs for UE3 have common parts.

[0233] Step 804e: AMF3 determines whether one or more candidate LMFs for UE3 have common parts with one or more candidate LMFs for UE1 or UE2. If one or more candidate LMFs for UE3 have common parts with one or more candidate LMFs for UE1, it indicates that AMF3 can select the same LMF for UE3 and UE1, and step 805 is performed. Alternatively, if one or more candidate LMFs for UE3 do not have common parts with one or more candidate LMFs for UE1 or one or more candidate LMFs for UE2, step 806 is performed.

[0234] In this step, if AMF3 receives candidate LMFs for UE1, UE2, and UE3, AMF3 may determine, based on the candidate LMFs for UE1, UE2, and UE3, whether one or more candidate LMFs for UE3 have common parts with one or more candidate LMFs for UE1 or UE2. If AMF3 receives second information, AMF3 may directly determine, based on the second information, whether one or more candidate LMFs for UE3 have common parts with one or more candidate LMFs for UE1 or UE2.

[0235] Step 805: LMF3 selects UE1 as the starting terminal for distance measurement and proceeds to step 807.

[0236] In this step, an example is used in which one or more candidate LMFs of UE1 have common parts with one or more candidate LMFs of UE3. If one or more candidate LMFs of UE2 have common parts with one or more candidate LMFs of UE3, AMF3 selects UE2 as the starting terminal for distance measurement. If both candidate LMFs of UE1 and UE2 have common parts with one or more candidate LMFs of UE3, AMF3 may select either UE1 or UE2 as the starting terminal for distance measurement.

[0237] Step 806: AMF3 randomly selects one terminal from UE1 and UE2 as the starting terminal for distance measurement, and proceeds to step 807.

[0238] In this example, the case where UE1 is selected as the starting terminal for distance measurement is used.

[0239] Step 807: AMF3 selects LMF3 and sends a positioning request to LMF3, where the positioning request may contain identifiers for UE1 and UE2 and instruction information for the terminal that initiated the distance measurement. Next, step 808 or step 809 is performed.

[0240] Step 808: LMF3 initiates and performs the ranging operation between UE1 and UE2, and then proceeds to step 810.

[0241] AMF3 can select an LMF from the common part of the candidate LMFs of UE3 and UE1. In this example, the common part includes LMF3. Therefore, AMF3 selects LMF3.

[0242] This step may involve a multi-step information exchange process and may involve the serving AMF of UE1 and UE2.

[0243] Step 809: AMF3 instructs the ranging-initiating terminal to perform the ranging operation by using GMLC, and then proceeds to step 810.

[0244] When AMF3 selects either UE1 or UE2 as the ranging source terminal, the LMF selected by AMF3 cannot directly send a request to the ranging source terminal to instruct it to perform ranging operations between UE1 and UE2. Therefore, GMLC is used to instruct the ranging source terminal to perform ranging operations.

[0245] Optionally, step 809 may include steps 809a to 809e.

[0246] Step 809a: LMF3 sends a position request to UE1's serving AMF (AMF1) by using GMLC3 as the rangening request source.

[0247] Step 809b: AMF1 initiates a range-measuring (ranging) positioning request for UE1 to LMF1 and requests the range-measuring (ranging) result between UE1 and UE2.

[0248] Step 809c: LMF1 begins performing ranging between UE1 and UE2. The process may involve LMF1, AMF1, UE1 and UE2, and optionally, RAN as well.

[0249] Step 809d: LMF1 returns the range measurement result to AMF1.

[0250] Step 809e: AMF1 returns the range measurement (ranging) result to LMF3 using GMLC1.

[0251] Step 810: LMF3 transmits a positioning response to AMF3, where the positioning response may contain the distance measurement result.

[0252] Step 811a: If the distance measurement is triggered by AF (see Step 801a), AMF3 transmits the distance measurement result to AF using GMLC3 and NEF.

[0253] Step 811b: If the distance measurement is triggered by UE3 (see Step 801b), AMF3 sends the distance measurement result to UE3. For example, the distance measurement result may be sent to UE3 using a downlink NAS message.

[0254] The above is illustrated by using three terminals as an example. In a two-terminal scenario, the LMF may also select the terminal that initiates the ranging process based on the principles of the procedure described above. In this scenario, LMF3 may select the terminal requesting positioning as the terminal that initiates the ranging process. In a scenario involving more than two ranging terminals, the LMF may also select the terminal that initiates the ranging process based on the principles of the procedure described above.

[0255] In another possible implementation, AMF3 may first select LMF3 for UE3, and then determine the starting terminal for distance measurement. In this case, AMF3 may obtain candidate LMFs for UE1 and UE2 (the method for obtaining candidate LMFs for UE1 and UE2 is the same as in the procedure above). If AMF determines that one or more candidate LMFs for UE1 include LMF3, UE1 can be used as the starting terminal for distance measurement. If AMF determines that one or more candidate LMFs for UE2 include LMF3, UE2 can be used as the starting terminal for distance measurement. If AMF determines that neither candidate LMFs for UE1 nor UE2 include LMF3, UE1 or UE2 can be used as the starting terminal for distance measurement. Refer to the process above for other steps.

[0256] Figure 9 is a diagram of the information exchange procedure in a third example according to an embodiment of the present invention. In the third example, the positioning request terminal is UE3, and the ranging terminals include UE1 and UE2. AMF1 is the serving AMF of UE1, AMF3 is the serving AMF of UE3, the LMF of UE1 is represented as LMF1, and the LMF of UE3 is represented as LMF3. Since the ranging requirement is visible to the AMF, the AMF selects the ranging initiation terminal. As shown in the figure, the procedure may include the following steps.

[0257] Step 901a: AF triggers the ranging requirement. For the implementation of this step, please refer to the relevant explanations in Figures 8A, 8B, and 8C.

[0258] Step 901b: UE3 triggers the ranging requirement. For the implementation of this step, please refer to the relevant explanations in Figures 8A, 8B, and 8C.

[0259] Step 902: AMF3 checks whether context information for UE1 or UE2 exists; if context information for UE1 exists, it executes step 903; or if neither context information for UE1 nor UE2 exists, it executes step 904.

[0260] For details on implementing this step, please refer to the relevant explanations in Figures 8A, 8B, and 8C.

[0261] Step 903: AMF3 selects UE1 as the starting terminal for ranging. Next, step 905 is performed.

[0262] In this step, an example is used where the context information for UE1 exists in AMF3. If the context information for UE2 exists in AMF3 but the context information for UE1 does not, AMF3 selects UE2 as the starting terminal for distance measurement. If the context information for both UE1 and UE2 exists in AMF3, AMF3 may select either UE1 or UE2 as the starting terminal for distance measurement.

[0263] Step 904: AMF3 randomly selects one terminal from UE1 and UE2 as the starting terminal for distance measurement, and proceeds to step 908.

[0264] In this example, the case where UE1 is selected as the starting terminal for distance measurement is used.

[0265] Step 905: AMF3 selects LMF3 and sends a positioning request to LMF3, where the positioning request may contain identifiers for UE1 and UE2 and instruction information for the terminal that initiated the distance measurement. Next, step 906 or step 907 is performed.

[0266] Step 906: LMF3 initiates and performs the ranging operation between UE1 and UE2, and then proceeds to step 908.

[0267] If context information for UE1 exists in AMF3, LMF3 may send a request to UE1 instructing it to perform a ranging operation between UE1 and UE2.

[0268] This step may involve a multi-step information exchange process and may involve the serving AMF of UE1 and UE2.

[0269] Step 907: LMF3 transmits the distance measurement result to AMF3, and then proceeds to step 909a or 909b.

[0270] Step 908: AMF3 instructs the distance measurement initiation terminal to perform the distance measurement operation by using GMLC, and then proceeds to step 909a or 909b.

[0271] When AMF3 selects either UE1 or UE2 as the ranging source terminal, the LMF selected by AMF3 cannot directly send a request to the ranging source terminal to instruct it to perform ranging operations between UE1 and UE2. Therefore, GMLC is used to instruct the ranging source terminal to perform ranging operations.

[0272] Optionally, step 908 may include steps 908a to 908e.

[0273] Step 908a: AMF3 sends a position request to UE1's serving AMF (AMF1) by using GMLC3 as the rangening request source.

[0274] Step 908b: AMF1 initiates a range-measuring (ranging) positioning request for UE1 to LMF1 and requests the range-measuring (ranging) result between UE1 and UE2.

[0275] Step 908c: LMF1 begins performing ranging between UE1 and UE2. The process may involve LMF1, AMF1, UE1 and UE2, and optionally, RAN as well.

[0276] Step 908d: LMF1 returns the F1 ranging result to AMF3.

[0277] Step 908e: AMF1 returns the range measurement (ranging) result to AMF3 using GMLC1.

[0278] Step 909a: If distance measurement is triggered by AF (see Step 901a), AMF3 transmits the distance measurement result to AF using GMLC3 and NEF.

[0279] Step 909b: If the distance measurement is triggered by UE3 (see Step 901b), AMF3 sends the distance measurement result to UE3. For example, the distance measurement result may be sent to UE3 using a downlink NAS message.

[0280] The above is illustrated by using three terminals as an example. In a two-terminal scenario, the LMF may also select the terminal that initiates the ranging process based on the principles of the procedure described above. In this scenario, LMF3 may select the terminal requesting positioning as the terminal that initiates the ranging process. In a scenario involving more than two ranging terminals, the LMF may also select the terminal that initiates the ranging process based on the principles of the procedure described above.

[0281] Figure 10 is a diagram of the information exchange procedure in a fourth example according to an embodiment of the present invention. In the fourth example, the positioning request terminal is UE3, and the ranging terminals include UE1 and UE2. AMF1 is the serving AMF of UE1, AMF3 is the serving AMF of UE3, the LMF of UE1 is represented as LMF1, and the LMF of UE3 is represented as LMF3. Since the ranging requirement is visible to the AMF, the AMF selects the ranging initiator terminal. The AMF also serves as a ranging requester (a network element in the network serves as a requester) and sends the request directly to the ranging initiator terminal's AMF via the N14 interface. The ranging initiator terminal's AMF sends the positioning request to the ranging initiator terminal's LMF. As shown in the figure, the procedure may include the following steps.

[0282] Step 1001a: AF triggers the ranging requirement. For the implementation of this step, refer to the relevant description in FIG. 9.

[0283] Step 1001b: UE3 triggers the ranging requirement. For the implementation of this step, refer to the relevant description in FIG. 9.

[0284] Step 1002: AMF3 checks whether the context information of UE1 or the context information of UE2 exists; if the context information of UE1 exists, it executes Step 1003, or if neither the context information of UE1 nor the context information of UE2 exists, it executes Step 1004.

[0285] For the implementation of this step, refer to the relevant description in FIG. 9.

[0286] Step 1003: AMF3 selects UE1 as the ranging start source terminal. Next, Step 1005 is executed.

[0287] In this step, an example where the context information of UE1 exists in AMF3 is used. If the context information of UE2 exists in AMF3 but the context information of UE1 does not exist in AMF3, AMF3 selects UE2 as the ranging start source terminal. If both the context information of UE1 and the context information of UE2 exist in AMF3, AMF3 may select either UE1 or UE2 as the ranging start source terminal.

[0288] Step 1004: AMF3 randomly selects one terminal from UE1 and UE2 as the ranging start source terminal and proceeds to Step 1006.

[0289] In this example, an example where UE1 is selected as the ranging start source terminal is used.

[0290] Step 1005: Trigger UE ranging process 1.

[0291] For example, step 1005 may include steps 1005a, 1005b, and 1005c.

[0292] Step 1005a: AMF3 selects LMF3 and sends a positioning request to LMF3, where the positioning request may contain identifiers for UE1 and UE2 and instruction information for the terminal that initiated the distance measurement.

[0293] Step 1005b: LMF3 starts and performs a ranging operation between UE1 and UE2, and then proceeds to step 1007a or 1007b.

[0294] If context information for UE1 exists in AMF3, LMF3 may send a request to UE1 instructing it to perform a ranging operation between UE1 and UE2.

[0295] This step may involve a multi-step information exchange process and may involve the serving AMF of UE1 and UE2.

[0296] Step 1005c: LMF3 transmits the distance measurement result to AMF3, and then proceeds to step 1007a or 1007b.

[0297] Step 1006: Trigger UE ranging process 2.

[0298] For example, step 1006 may include steps 1006a to 1006g.

[0299] Step 1006a: AMF3 sends a query request to the UDM, requesting to retrieve the identifier of the serving AMF for UE1. The query request may include the identifier of UE1.

[0300] Step 1006b: The UDM returns a query response to AMF3, where the query response may hold an identifier for the serving AMF of UE1 (i.e., AMF1), and optionally may further hold registration area information for UE1.

[0301] Step 1006c: AMF3 transmits a location request to AMF1, where the location request may hold identifiers for UE1 and UE2, and optionally further hold instruction information indicating that UE1 should be used as the starting terminal for distance measurement.

[0302] Step 1006d: AMF1 initiates a range-measuring (ranging) positioning request for UE1 to LMF1 and requests the range-measuring (ranging) result between UE1 and UE2.

[0303] Step 1006e: LMF1 begins performing ranging between UE1 and UE2. The process may involve LMF1, AMF1, UE1 and UE2, and optionally, RAN as well.

[0304] Step 1006f: LMF1 returns the range measurement result to AMF1.

[0305] Step 1006g: AMF1 returns the range measurement result to AMF3.

[0306] Step 1007a: If distance measurement is triggered by AF (see Step 1001a), AMF3 transmits the distance measurement result to AF using GMLC3 and NEF.

[0307] Step 1007b: If the distance measurement is triggered by UE3 (see Step 1001b), AMF3 sends the distance measurement result to UE3. For example, the distance measurement result may be sent to UE3 using a downlink NAS message.

[0308] The above is described by way of example using three terminals. In the scenario of two terminals, the LMF can also select the ranging start source terminal based on the principle of the above procedure. In this scenario, LMF3 can select the positioning request terminal as the ranging start source terminal. In a scenario with more than two ranging terminals, the LMF can also select the ranging start terminal based on the principle of the above procedure.

[0309] FIG. 11 is a diagram of an information exchange procedure in a fifth example according to an embodiment of the present application. In the fifth example, the positioning request terminal is UE3, and the ranging terminals include UE1 and UE2. AMF1 is the serving AMF of UE1, AMF3 is the serving AMF of UE3, the LMF of UE1 is represented as LMF1, and the LMF of UE3 is represented as LMF3. The GMLC of the positioning request terminal selects the ranging start source terminal. As shown in the figure, the procedure may include the following steps.

[0310] Step 1101: The AF triggers a ranging requirement.

[0311] Optionally, the AF may send a location request to AMF3 to request an SL ranging service. The location request may hold the identifiers (UE1 ID and UE2 ID) of the ranging terminals UE1 and UE2, and optionally may further hold the identifier (UE3 ID) of the positioning request terminal UE3, and further may hold information such as the SL ranging service type, measurement type, and SL ranging requirement.

[0312] Optionally, the request triggered by the AF may be sent to the GMLC (i.e., GMLC3) of the positioning request terminal by using the NEF.

[0313] Step 1102a: UE3 or UE1 triggers a ranging requirement.

[0314] For example, UE3 triggers a ranging requirement. UE3 sends a location request to AMF3, requesting an SL ranging service. The location request may contain identifiers for ranging terminals UE1 and UE2 (UE1 ID and UE2 ID), and may also contain information such as the SL ranging service type, measurement type, and SL ranging requirement.

[0315] Step 1102b: AMF3 sends a location request to GMLC3 and requests SL ranging service. The location request holds the identifiers of ranging terminals UE1 and UE2 (UE1 ID and UE2 ID), optionally holds the UE3 ID, and may also hold information such as the SL ranging service type, measurement type, and SL ranging requirement.

[0316] In this step, AMF3 serves as the distance measurement request source and sends the distance measurement requirements to GMLC3 using a position request message.

[0317] Step 1103a: GMLC3 sends a query request to UDM, which may hold the UE1 ID and UE2 ID, and requests the identifiers of the serving AMFs for UE1 and UE2.

[0318] Step 1103b: The UDM returns a query response to the GMLC3, which may contain the identifier of the Serving AMF for UE1 (UE1 AMF ID) and the identifier of the Serving AMF for UE2 (UE2 AMF ID). Optionally, the query response may also contain registration area information for UE1 and UE2.

[0319] In the possible alternative solutions of steps 1103a to 1103b, GMLC3 sends query request 1 to the UDM, which holds the identifier of UE1, and receives query response 1, which is returned by the UDM, which holds the identifier of the serving AMF for UE1. Optionally, query response 1 may further include registration area information for UE1. GMLC3 sends query request 2 to the UDM, which holds the identifier of UE2, and receives query response 2, which is returned by the UDM, which holds the identifier of the serving AMF for UE2. Optionally, query response 2 may further include registration area information for UE2.

[0320] Optionally, GMLC3 may further obtain reachability information for UE1 and UE2, UDM context information for UE1 and UE2, and similar information from the UDM, and may use the obtained information as a basis for selecting the starting terminal for distance measurement.

[0321] Step 1104: Based on the information obtained from the UDM, GMLC3 selects the starting terminal for distance measurement from UE1 and UE2.

[0322] Optionally, GMLC3 may select a test initiation terminal based on the reachability of UE1 and UE2, and the subscription information of UE1 and UE2, obtained from the UDM.

[0323] In this example, we will use the case where UE1 is selected as the starting terminal for distance measurement for illustrative purposes.

[0324] Step 1105: GMLC3 sends a position request to the serving AMF (AMF1) of the distance measurement initiation terminal UE1 and requests the distance measurement result between UE1 and UE2.

[0325] Optionally, the location request may hold identifiers for UE1 and UE2, and optionally, may further hold instructional information indicating that UE1 is to be used as the starting terminal for ranging. Furthermore, the location request may hold information such as the SL ranging service type, measurement type, and SL ranging requirements.

[0326] Optionally, if AMF1 is not currently within the service range of GMLC3, GMLC3 may select GMLC1 and initiate a location request to AMF1 by using GMLC1.

[0327] Step 1106: AMF1 sends a positioning request to LMF1 and requests the distance measurement result between UE1 and UE2.

[0328] Optionally, the location request may hold identifiers for UE1 and UE2, and instructional information indicating that UE1 is to be used as the starting terminal for ranging. Furthermore, the location request may hold information such as the SL ranging service type, measurement type, and SL ranging requirements.

[0329] Step 1107: LMF1 begins performing a ranging operation between UE1 and UE2. The process may involve LMF1, AMF1, UE1 and UE2, and optionally, RAN as well.

[0330] Step 1108: LMF1 returns the range measurement result to AMF1.

[0331] Step 1109: AMF1 returns the range measurement (ranging) results to LMF3 using GMLC3.

[0332] Step 1110: If the distance measurement is triggered by AF (see Step 1101), the GMLC3 transmits the distance measurement result to AF via the NEF.

[0333] Step 1111a: If the distance measurement is triggered by UE3 (see Steps 1102a and 1102b), GMLC3 sends the distance measurement result to AMF3.

[0334] Step 1111b: AMF3 sends the distance measurement results to UE3.

[0335] The above is illustrated by using three terminals as an example. In a two-terminal scenario, the LMF may also select the terminal that initiates the ranging process based on the principles of the procedure described above. In this scenario, LMF3 may select the terminal requesting positioning as the terminal that initiates the ranging process. In a scenario involving more than two ranging terminals, the LMF may also select the terminal that initiates the ranging process based on the principles of the procedure described above.

[0336] According to the procedure shown in Figures 7A, 7B, and any one of Figures 7C to 11, when the AMF and / or LMF of UE1, UE2, and UE3 are different, the appropriate UE is selected from UE1 and UE2 as the starting UE for distance measurement (starting UE), and this UE is used as the starter to initiate the distance measurement operation on the PC5 interface, thereby avoiding interaction between multiple AMFs and / or LMFs and reducing complexity.

[0337] Based on the same technical concept, embodiments of the present invention further provide a communication device. The communication device can perform the procedure performed by the LMF3 in any one of the procedures shown in Figures 5 to 9.

[0338] As shown in Figure 12, the communication device 1200 may include a processing unit 1201 and a transmitting / receiving unit 1202. The transmitting / receiving unit 1202 is connected to the processing unit 1201.

[0339] The transmitting / receiving unit 1202 is configured to receive a first request, which is used to request that positioning be performed based on at least one ranging terminal.

[0340] The processing unit 1201 is configured to: determine the distance measurement initiation terminal, where the distance measurement initiation terminal is one of at least one distance measurement terminals and the distance measurement initiation terminal satisfies the first requirement; and instruct the distance measurement initiation terminal to start distance measurement by using the transmit / receive unit 1202.

[0341] Optionally, the processing unit 1201 is configured to determine a first terminal as the starting terminal for distance measurement, where information about the first terminal exists in the first network element, and the first terminal is at least one of the distance measurement terminals.

[0342] When the communication device 1200 performs a procedure carried out by the first network element (e.g., LMF) in Figures 5, 6, or 7A, 7B, and 7C, the functions of the above-mentioned functional module may include the following:

[0343] Specifically, the processing unit 1201 is configured such that, if information about any one of at least one ranging terminal is not present in the communication device, the communication device determines a second terminal as the terminal from which ranging was initiated, where the second terminal is one of at least one ranging terminal.

[0344] Optionally, the processing unit 1201 is configured to: obtain identifiers for the Serving Access and Mobility Management Function (AMF) of at least one ranging terminal from the UDM by using the transmitting / receiving unit 1202; obtain one or more candidate LMFs for at least one ranging terminal from the Network Repository Function (NRF) by using the transmitting / receiving unit 1202 based on the identifiers for the Serving AMF of at least one ranging terminal; and, if one or more candidate LMFs for a second terminal include a communication device, determine that the communication device can be used as the LMF for the second terminal and determine the second terminal as the starting terminal for ranging.

[0345] Optionally, the processing unit 1201 is configured to send a first query request to the NRF by using the transmit / receive unit 1202, where the first query request holds an identifier for the serving AMF of at least one ranging terminal. The transmit / receive unit 1202 receives the first query response sent by the NRF, where the first query response holds an identifier for one or more candidate LMFs of at least one ranging terminal.

[0346] Optionally, the processing unit 1201 is configured to: obtain the identifier of the serving AMF of at least one ranging terminal from the UDM by using the transmitting / receiving unit 1202; obtain first information from the NRF based on the identifier of the serving AMF of at least one ranging terminal by using the transmitting / receiving unit 1202, where the first information indicates that the communication device can be used as the LMF of the second terminal; and determine the second terminal as the ranging start terminal based on the first information.

[0347] Optionally, the processing unit 1201 is configured to send a second query request to the NRF by using the transmit / receive unit 1202, where the second query request holds the identifier of the serving AMF of at least one ranging terminal. The transmit / receive unit 1202 is configured to receive the second query response sent by the NRF, where the second query response holds the first information.

[0348] Optionally, the second query request holds a communication device identifier or first instruction information, and the communication device identifier or first instruction information indicates that if at least one ranging terminal satisfies the first condition, the communication device can be used as the LMF of the ranging terminal that satisfies the first condition, and the first information is returned. One or more candidate LMFs of the ranging terminal that satisfies the first condition include the communication device, and the ranging terminal that satisfies the first condition includes the second terminal.

[0349] Optionally, the processing unit 1201 is configured to send a third query request to the UMD by using the transmit / receive unit 1202, where the third query request holds the identifier of at least one ranging terminal. The transmit / receive unit 1202 is configured to receive the third query response sent by the UMD, where the third query response holds the identifier of the serving AMF of at least one ranging terminal.

[0350] When the communication device 1200 performs the procedure carried out by the AMF3 in Figures 5, 6, and 8A, 8B, and 8C to 10, the functions of the above-mentioned functional module may include the following:

[0351] Specifically, the processing unit 1201 is configured to determine a third terminal as the starting terminal for distance measurement if information about any one of at least one distance measuring terminal is not available in the communication device, where the third terminal is at least one of the distance measuring terminals.

[0352] Optionally, the processing unit 1201 is configured to obtain the identifier of the serving AMF of at least one ranging terminal from the UDM by using the transmitting / receiving unit 1202; obtain one or more candidate LMFs of at least one ranging terminal from the NRF based on the identifier of the serving AMF of at least one ranging terminal by using the transmitting / receiving unit 1202; and, if one or more candidate LMFs of a third terminal include the LMF of a positioning request terminal, to determine the third terminal as the terminal from which ranging was initiated.

[0353] Optionally, the processing unit 1201 is configured to: obtain the identifier of the serving AMF of at least one ranging terminal from the UDM by using the transceiver unit 1202; obtain one or more candidate LMFs of at least one ranging terminal and one or more candidate LMFs of the positioning request terminal from the NRF based on the identifier of the serving AMF of at least one ranging terminal and the identifier of the serving AMF of the positioning request terminal, where the serving AMF of the positioning request terminal is a communication device; and determine the third terminal as the starting terminal for ranging if one or more candidate LMFs of the third terminal and one or more candidate LMFs of the positioning request terminal have a common part.

[0354] Optionally, the processing unit 1201 is configured to send a fourth query request to the NRF by using the transmit / receive unit 1202, where the fourth query request holds an identifier for the serving AMF of at least one ranging terminal. The transmit / receive unit 1202 is configured to receive a first query response sent by the NRF, where the first query response holds an identifier for one or more candidate LMFs of at least one ranging terminal.

[0355] Optionally, the processing unit 1201 is configured to obtain the identifier of the serving AMF of at least one ranging terminal from the UDM by using the transmitting / receiving unit 1202; to obtain second information from the NRF based on the identifier of the serving AMF of at least one ranging terminal by using the transmitting / receiving unit 1202, where the second information indicates that one or more candidate LMFs of the third terminal include the LMF of the positioning request terminal; and to determine the third terminal as the ranging initiation terminal based on the second information.

[0356] Optionally, the processing unit 1201 specifically obtains the identifier of the serving AMF of at least one ranging terminal from the UDM by using the transmitting / receiving unit 1202; obtains second information from the NRF based on the identifiers of the serving AMFs of at least one ranging terminal and the identifier of the serving AMF of the positioning request terminal by using the transmitting / receiving unit 1202, where the second information indicates that one or more candidate LMFs of the third terminal and one or more candidate LMFs of the positioning request terminal have a common part, and the serving AMF of the positioning request terminal is a communication terminal; and is configured to determine the third terminal as the starting terminal for ranging based on the second information.

[0357] Optionally, the processing unit 1201 is configured to send a fifth query request to the NRF by using a transmit / receive unit, where the fifth query request holds at least the identifier of the serving AMF of at least one ranging terminal. The transmit / receive unit 1202 is configured to receive a fifth query response sent by the NRF, where the fifth query response holds the second information.

[0358] Optionally, the fifth query request holds a communication device identifier or second instruction information, the communication device identifier or second instruction information indicates that the second information is returned if at least one ranging terminal satisfies the second condition, where one or more candidate LMFs of ranging terminals satisfying the second condition and one or more candidate LMFs of positioning request terminals have a common part; or one or more candidate LMFs of ranging terminals satisfying the second condition include the LMF of positioning request terminals, where ranging terminals satisfying the second condition include the third terminal.

[0359] Optionally, the processing unit 1201 is configured to send a sixth query request to the UMD by using a transmit / receive unit, where the sixth query request holds the identifier of at least one ranging terminal. The transmit / receive unit 1202 is configured to receive the sixth query response sent by the UMD, where the sixth query response holds the identifier of the serving AMF of at least one ranging terminal.

[0360] Optionally, the processing unit 1201 is configured to send a second request to the second LMF by specifically using the transmit / receive unit 1202, where the second request holds instruction information of the distance measurement initiation terminal.

[0361] The communication device 1200 can implement the steps of the method in the above embodiment and achieve the same technical effects. The parts of the embodiment of the method and the beneficial effects identical to those in this embodiment will not be described in detail again here.

[0362] For ease of understanding, Figure 13 shows only the structure necessary for the communication device 1300 to perform the method described in the present application, and does not impose any limitation on the fact that the communication device may have more components than those in the present application. The communication device 1300 may be configured to perform steps performed by the relevant network elements in the embodiments of the above method. For example, the relevant network elements may be first network elements (e.g., first LMF, first AMF, first GMLC, and similar).

[0363] The communication device 1300 may include a transceiver 1301, a memory 1303, and a processor 1302. The transceiver 1301, the memory 1303, and the processor 1302 may be connected by using a bus 1304. The transceiver 1301 may be used by the communication device to perform communication, for example, to transmit or receive signals. The memory 1303 is coupled to the processor 1302 and may be configured to store programs and data necessary to implement the functions of the communication device 1300. The memory 1303 and the processor 1302 may be integrated or independent of each other.

[0364] For example, the transceiver 1301 may be a communication port, for example, a communication port (or interface) used for communication between network elements. The transceiver 1301 may also be referred to as a transceiver unit or a communication unit. The processor 1302 may be implemented using a processing chip or processing circuit. The transceiver 1301 may receive or transmit information wirelessly or via a wired connection.

[0365] In addition, depending on the actual usage requirements, the communication device provided in the embodiments of the present application may include a processor, which calls an external transceiver and / or memory to implement the above functions, steps, or operations. The communication device may further include memory, which the processor may call and execute a program stored in memory to implement the above functions, steps, or operations. Alternatively, the communication device may include a processor and a transceiver (or communication interface), which the processor may call and execute a program stored in external memory to implement the above functions, steps, or operations. Alternatively, the communication device may include a processor, memory, and a transceiver.

[0366] Based on the same concept as the embodiments of the above-described method, embodiments of the present application further provide a computer-readable storage medium. The computer-readable storage medium stores program instructions (or referred to as computer programs or instructions). When the program instructions are executed by a processor, the computer is able to perform the actions performed by the first network element in the embodiments of the above-described method and any possible implementation of the embodiments of the above-described method.

[0367] Based on the same concept as the embodiments of the above-described method, the present application further provides a computer program product including program instructions. When the computer program product is invoked and executed by a computer, the computer may implement the operations performed by the first network element in the embodiments of the above-described method and any possible implementation of the embodiments of the above-described method.

[0368] Based on the same concept as the embodiments of the above-described method, the present application further provides a chip or chip system. The chip is coupled to a transceiver and is configured to implement the operations performed by the first network element in the embodiments of the above-described method and any possible implementation of the embodiments of the above-described method. The chip system may include the chip and components such as memory and communication interfaces.

[0369] Those skilled in the art will recognize that embodiments of the present invention may be provided as methods, systems, or computer program products. Accordingly, the present invention may take the form of complete hardware embodiments, complete software embodiments, or embodiments combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk memory, CD-ROM, and optical memory) containing computer-usable program code.

[0370] This application will be described with reference to flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to this application. It should be understood that each step and / or block in the flowcharts and / or block diagrams, and / or combinations of steps and / or blocks in the flowcharts and / or block diagrams, can be implemented using computer program instructions. These computer program instructions may be provided to a processor of a general-purpose computer, an application-specific computer, an embedded processor, or another programmable data processing device to produce a machine, and as a result, instructions executed by the processor of the computer or another programmable data processing device produce a device for implementing one or more steps in the flowchart and / or one or more blocks in the block diagram.

[0371] These computer program instructions may also be stored in computer-readable memory, which instructs the computer or another programmable data processing device to operate in a specific manner, resulting in a product that includes an instruction unit. The instruction unit implements one or more steps in a flowchart and / or one or more blocks in a block diagram.

[0372] Computer program instructions can alternatively be loaded into a computer or another programmable data processing device, resulting in a series of operations and steps being executed on the computer or another programmable device, thereby generating a computer implementation process. Therefore, instructions executed on the computer or another programmable device provide steps for implementing a specific function in one or more steps of a flowchart and / or one or more blocks of a block diagram.

[0373] Naturally, a person skilled in the art may make various modifications and variations of this application without departing from the scope of protection. This application is intended to encompass such modifications and variations of this application insofar as they fall within the scope of protection defined by the following claims and in the equivalent art thereof. 。 [Item 1] The first step involves receiving a first request by a first network element, the first request being used to request that positioning be performed based on at least one ranging terminal; The step of determining the distance measurement initiation terminal by the first network element, wherein the distance measurement initiation terminal is one of the at least one distance measurement terminals, and the distance measurement initiation terminal satisfies the first requirement; and The first network element instructs the distance measurement initiation terminal to start distance measurement. A positioning method that includes [a specific feature / feature]. [Item 2] The step of determining the distance measurement initiation terminal by the first network element, wherein the distance measurement initiation terminal is one of the at least one distance measurement terminals, and the distance measurement initiation terminal satisfies the first requirement: In the step of determining the first terminal as the distance measurement initiation terminal using the first network element, where information about the first terminal exists in the first network element, and the first terminal is one of the at least one distance measurement terminals, The method described in item 1, including the method described in item 1. [Item 3] The first network element is a first position management function LMF; The step of determining the distance measurement initiation terminal by the first network element, wherein the distance measurement initiation terminal is one of the at least one distance measurement terminals, and the distance measurement initiation terminal satisfies the first requirement: If information about any one of the at least one distance measuring terminals is not present in the first LMF, the first LMF determines the second terminal as the distance measurement initiation terminal, where the second terminal is one of the at least one distance measuring terminals. The method described in item 1, including the method described in item 1. [Item 4] The step of determining the second terminal as the starting terminal for the distance measurement using the first LMF is: The first LMF obtains the identifier of the serving access and mobility management function AMF of the at least one ranging terminal from the integrated data management UDM; The first LMF obtains one or more candidate LMFs of the at least one ranging terminal from the network repository function NRF based on the identifier of the serving AMF of the at least one ranging terminal; and If one or more candidate LMFs of the second terminal include the first LMF, the first LMF is determined to be usable as the LMF of the second terminal, and the second terminal is determined to be the terminal from which the distance measurement was initiated. The method described in item 3, comprising: [Item 5] The step of obtaining one or more candidate LMFs of the at least one ranging terminal from the NRF based on the identifier of the serving AMF of the at least one ranging terminal using the first LMF is: The first LMF transmits a first query request to the NRF, wherein the first query request holds the identifier of the serving AMF of the at least one ranging terminal; and The first LMF receives a first query response transmitted by the NRF, wherein the first query response holds one or more identifiers of the one or more candidate LMFs of the at least one ranging terminal. The method described in item 4, including the method described in item 4. [Item 6] The step of determining the second terminal as the starting terminal for distance measurement using the first LMF is: The first LMF obtains the identifier of the serving AMF of the at least one ranging terminal from the UDM; The first LMF obtains first information from the NRF based on the identifier of the serving AMF of the at least one ranging terminal, wherein the first information indicates that the first LMF can be used as the LMF of the second terminal; and The first LMF determines the second terminal as the starting terminal for distance measurement based on the first information. The method described in item 3, including the method described in item 3. [Item 7] The step of obtaining first information from the NRF based on the identifier of the serving AMF of the at least one ranging terminal using the first LMF is: The first LMF transmits a second query request to the NRF, wherein the second query request holds the identifier of the serving AMF of the at least one ranging terminal; and The first LMF receives the second query response transmitted by the NRF, where the second query response holds the first information. The method described in item 6, including the method described in item 6. [Item 8] The second query request holds the identifier or first instruction information of the first LMF, and the identifier or first instruction information of the first LMF is: If at least one of the distance measuring terminals satisfies the first condition, the first LMF can be used as the LMF of the distance measuring terminal that satisfies the first condition, and the first information is returned, where one or more candidate LMFs of the distance measuring terminal that satisfies the first condition include the first LMF, and the distance measuring terminal that satisfies the first condition includes the second terminal. The method described in item 7, which instructs the following. [Item 9] The step of obtaining the identifier of the serving AMF of the at least one ranging terminal from the UDM using the first LMF is: The first LMF sends a third query request to the UDM, where the third query request holds the identifier of the at least one ranging terminal; and The first LMF receives a third query response transmitted by the UMD, wherein the third query response holds the identifier of the serving AMF of the at least one ranging terminal. The method described in any one of items 4 through 8, including the method described in item 4 through 8. [Item 10] The first network element is the first AMF; The step of determining the distance measurement initiation terminal by the first network element, wherein the distance measurement initiation terminal is one of the at least one distance measurement terminals, and the distance measurement initiation terminal satisfies the first requirement: If information about any one of the at least one distance measuring terminals is not present in the first AMF, the first AMF determines the third terminal as the distance measurement initiation terminal, where the third terminal is one of the at least one distance measuring terminals. The method described in item 1, including the method described in item 1. [Item 11] The step of determining the third terminal as the starting terminal for the distance measurement using the first AMF is: The first AMF obtains the identifier of the serving AMF of the at least one ranging terminal from the UDM; The first AMF obtains one or more candidate LMFs of the at least one ranging terminal from the NRF based on the identifier of the serving AMF of the at least one ranging terminal; and If one or more candidate LMFs of the third terminal include the LMF of the positioning request terminal, the third terminal is determined to be the terminal from which the distance measurement was initiated. including, or; The step of determining the third terminal as the starting terminal for the distance measurement using the first AMF is: The first AMF obtains the identifier of the serving AMF of the at least one ranging terminal from the UDM; The first AMF obtains one or more candidate LMFs for the at least one ranging terminal and one or more candidate LMFs for the positioning request terminal from the NRF based on the identifier of the serving AMF of the at least one ranging terminal and the identifier of the serving AMF of the positioning request terminal, where the serving AMF of the positioning request terminal is the first AMF; and If the one or more candidate LMFs of the third terminal and the one or more candidate LMFs of the positioning request terminal have a common portion, the third terminal is determined to be the terminal from which the distance measurement was initiated. The method described in item 10, including the method described in item 10. [Item 12] The step of obtaining one or more candidate LMFs of the at least one ranging terminal from the NRF based on the identifier of the serving AMF of the at least one ranging terminal using the first AMF is: The first LMF transmits a fourth query request to the NRF, wherein the fourth query request holds the identifier of the serving AMF of the at least one ranging terminal; and The first LMF receives a first query response transmitted by the NRF, wherein the first query response holds one or more identifiers of the one or more candidate LMFs of the at least one ranging terminal. The method described in item 11, including the method described in item 11. [Item 13] The step of determining the third terminal as the starting terminal for the distance measurement using the first AMF is: The first AMF obtains the identifier of the serving AMF of the at least one ranging terminal from the UDM; The first AMF obtains second information from the NRF based on the identifier of the serving AMF of the at least one ranging terminal, wherein the second information indicates that one or more candidate LMFs of the third terminal include the LMF of the positioning request terminal; and The first AMF determines the third terminal as the starting terminal for distance measurement based on the second information. Includes; or, The step of determining the third terminal as the starting terminal for the distance measurement using the first AMF is: The first AMF obtains the identifier of the serving AMF of the at least one ranging terminal from the UDM; The first AMF is used to obtain second information from the NRF based on the identifier of the serving AMF of the at least one ranging terminal and the identifier of the serving AMF of the positioning request terminal, wherein the second information indicates that one or more candidate LMFs of the third terminal and one or more candidate LMFs of the positioning request terminal have a common part, and the serving AMF of the positioning request terminal is the first AMF; and The first AMF determines the third terminal as the starting terminal for distance measurement based on the second information. The method described in item 10, including the method described in item 10. [Item 14] The step of obtaining second information from the NRF based on the identifier of the serving AMF of the at least one ranging terminal using the first AMF is: The first AMF transmits a fifth query request to the NRF, wherein the fifth query request holds at least the identifier of the serving AMF of the at least one ranging terminal; and The first AMF receives the fifth query response transmitted by the NRF, where the fifth query response holds the second information. The method described in item 13, including the method described in item 13. [Item 15] The fifth query request holds the identifier or second instruction information of the first AMF, and the identifier or second instruction information of the first AMF is: If a distance measuring terminal that satisfies the second condition exists in at least one of the distance measuring terminals, the second information is returned, wherein one or more candidate LMFs of the distance measuring terminal that satisfies the second condition and the one or more candidate LMFs of the positioning request terminal have a common part; or, one or more candidate LMFs of the distance measuring terminal that satisfies the second condition include the LMF of the positioning request terminal, wherein the distance measuring terminal that satisfies the second condition includes the third terminal. The method described in item 14, which instructs the following. [Item 16] The step of obtaining the identifier of the serving AMF of the at least one ranging terminal from the UDM using the first AMF is: The first AMF sends a sixth query request to the UDM, wherein the sixth query request holds the identifier of the at least one ranging terminal; and The first AMF receives a sixth query response transmitted by the UMD, wherein the sixth query response holds the identifier of the serving AMF of the at least one ranging terminal. The method described in any one of items 11 to 15, including the method described in item 11 to 15. [Item 17] The first network element is the first AMF; The step of instructing the distance measurement initiation terminal to start distance measurement by the first network element is: In the step where the first AMF transmits the second request to the second LMF, the second request holds the instruction information of the distance measurement initiation terminal. The method described in any one of items 1, 2, and 10-15, including the method described in item 1, 2, and 10-15. [Item 18] The step of receiving a first position request, where the first position request is used to request that positioning be performed based on at least one ranging terminal; and In the step of determining the terminal from which the distance measurement was initiated, the terminal from which the distance measurement was initiated is one of the at least one distance measurement terminals. A positioning method applicable to the first gateway mobile location center GMLC, comprising the above. [Item 19] The aforementioned step of determining the terminal from which the distance measurement was initiated is: Steps to determine the starting terminal for distance measurement based on reachability information and / or terminal subscription information of the at least one distance measuring terminal. The method described in item 18, including the method described in item 18. [Item 20] The method according to item 19, further comprising the step of obtaining the reachability information and / or the terminal subscription information of the at least one ranging terminal from an integrated data management UDM. [Item 21] The step of obtaining the reachability information and / or terminal subscription information of the at least one ranging terminal from the UDM is: The steps include sending a first query request containing the identifier of the first ranging terminal to the UDM and receiving a first query response sent by the UDM, wherein the first query response contains reachability information and / or terminal subscription information of the first ranging terminal; and The steps include sending a second query request containing the identifier of the second distance measuring terminal to the UDM and receiving a second query response sent by the UDM, wherein the second query response contains reachability information and / or terminal subscription information of the second distance measuring terminal. The method described in item 20, including the method described in item 20. [Item 22] The steps include sending a query request to the UDM that holds the identifier of the first distance measuring terminal, and receiving a query response sent by the UDM, wherein the query response holds the identifier of the serving access and mobility management function AMF of the first distance measuring terminal; and The step of sending a query request containing the identifier of the second distance measuring terminal to the UDM and receiving a query response sent by the UDM, wherein the query response contains the identifier of the serving AMF of the second distance measuring terminal, The method according to any one of items 18 to 21, further comprising: [Item 23] The step of receiving the first position request is: In the step of receiving the first position request from the serving AMF of the positioning request terminal, the first position request holds an identifier of the at least one ranging terminal, The method described in any one of items 18 to 22, including the method described in item 18 to 22. [Item 24] In the step of transmitting a second position request to the first AMF, the second position request is used to request the acquisition of a distance measurement result between the distance measuring terminal and another distance measuring terminal at the at least one distance measuring terminal, The method described in any one of items 18 to 23, further including the method described in any one of items 18 to 23. [Item 25] The method according to item 24, wherein the second position request holds first information, the first information indicates the distance measurement initiation terminal, the first AMF is the serving AMF of the distance measurement initiation terminal, and the distance measurement initiation terminal is one of the at least one distance measurement terminals. [Item 26] The step of receiving the distance measurement result transmitted by the serving AMF of the distance measurement initiation terminal; and Steps to transmit the distance measurement result to the serving AMF of the positioning request terminal. The method described in any one of items 18 to 25, further comprising: [Item 27] The method according to any one of items 18 to 26, wherein the first GMLC is a GMLC that serves the positioning request terminal. [Item 28] A communication device comprising one or more processors, wherein the one or more memories store one or more computer programs, and the one or more computer programs include instructions, and when the instructions are executed by the one or more processors, the communication device is capable of performing the method described in any one of items 1 to 17 or any one of items 18 to 27. [Item 29] A computer-readable storage medium containing a computer program, wherein when the computer program is executed on an electronic device, the electronic device is capable of performing the method described in any one of items 1 to 17 or the method described in any one of items 18 to 27. [Item 30] A computer program product wherein, when the computer program product is executed on an electronic device, the electronic device is capable of performing the method described in any one of items 1 to 17 or the method described in any one of items 18 to 27. [Item 31] A chip system comprising memory configured to store a computer program, and a processor, wherein the processor retrieves the computer program from the memory, and after executing the computer program, the electronic device on which the chip system is installed performs the method described in any one of items 1 to 17, or the method described in any one of items 18 to 27.

Claims

1. A positioning method, A first network element receives a first request, which is used to request that positioning be performed based on at least one ranging terminal; If information about the first terminal exists in the first network element, the first network element determines the first terminal as the terminal from which distance measurement was initiated, where the first terminal is one of the at least one distance measurement terminals; and The first network element instructs the distance measurement initiation terminal to start distance measurement. A method that includes [a certain feature].

2. The method according to claim 1, wherein the at least one distance measuring terminal includes the first terminal and the second terminal, and information about the second terminal is not present in the first network element.

3. The method according to claim 1, wherein the information relating to the first terminal includes positioning context information or distance measurement context information of the first terminal.

4. The first network element is a first location management function; The first request is transmitted transparently as a container to the first location management function. The method according to claim 1.

5. The first network element is a first location management function; The aforementioned method is: If information about any one of the at least one distance measuring terminals is not present in the first position management function, the first position management function determines the second terminal as the distance measurement initiation terminal, where the second terminal is one of the at least one distance measuring terminals. The method according to claim 1, including the method described in claim 1.

6. The step of determining the second terminal as the starting terminal for distance measurement using the first position management function is as follows: The first location management function obtains identifiers for the serving access and mobility management functions of the at least one ranging terminal from the integrated data management; The first position management function obtains one or more candidate position management functions of the at least one distance measuring terminal from the network repository function based on the identifier of the serving access and mobility management functions of the at least one distance measuring terminal; and If one or more candidate location management functions of the second terminal include the first location management function, the first location management function is determined to be usable as the location management function of the second terminal, and the second terminal is determined to be the terminal from which the distance measurement was initiated. The method according to claim 5, comprising:

7. The first position management function obtains one or more candidate position management functions of the at least one distance measuring terminal from the network repository function based on the identifier of the serving access and mobility management functions of the at least one distance measuring terminal: The first location management function sends a first query request to the network repository function, wherein the first query request holds the identifier of the serving access and mobility management function of the at least one ranging terminal; and The first position management function receives a first query response transmitted by the network repository function, wherein the first query response holds one or more identifiers of the one or more candidate position management functions of the at least one ranging terminal. The method according to claim 6, including the method described in claim 6.

8. The step of determining the second terminal as the starting terminal for distance measurement using the first position management function is as follows: The first location management function obtains identifiers for the serving access and mobility management functions of the at least one ranging terminal from the integrated data management; The first location management function obtains first information from the network repository function based on the identifier of the serving access and mobility management function of the at least one ranging terminal, wherein the first information indicates that the first location management function can be used as the location management function of the second terminal; and The first position management function determines the second terminal as the starting terminal for distance measurement based on the first information. The method according to claim 5, including the method described in claim 5.

9. The step of obtaining first information from the network repository function based on the identifier of the serving access and mobility management function of the at least one ranging terminal by the first location management function is: The first location management function sends a second query request to the network repository function, wherein the second query request holds the identifier of the serving access and mobility management function of the at least one ranging terminal; and The first location management function receives a second query response transmitted by the network repository function, where the second query response holds the first information. The method according to claim 8, including the method described in claim 8.

10. The second query request holds the identifier or first instruction information of the first location management function, and the identifier or first instruction information of the first location management function is: If at least one of the distance measuring terminals satisfies the first condition, the first position management function can be used as the position management function of the distance measuring terminal that satisfies the first condition, and the first information is returned, where one or more candidate position management functions of the distance measuring terminal that satisfies the first condition include the first position management function, and the distance measuring terminal that satisfies the first condition includes the second terminal. The method according to claim 9, which provides instructions for the following.

11. The first position management function obtains identifiers for the serving access and mobility management functions of the at least one ranging terminal from the integrated data management: The first position management function sends a third query request to the integrated data management, where the third query request holds the identifier of the at least one ranging terminal; and The first location management function receives a third query response transmitted by the integrated data management, wherein the third query response holds the identifier of the serving access and mobility management function of the at least one ranging terminal. The method according to any one of claims 6 to 10, including the method described in any one of claims 6 to 10.

12. The first network element is a first access and mobility management function; The aforementioned method is: If information about any one of the at least one ranging terminals is not present in the first access and mobility management function, the first access and mobility management function determines the third terminal as the ranging source terminal, where the third terminal is one of the at least one ranging terminals. The method according to claim 1, including the method described in claim 1.

13. The step of determining the third terminal as the starting terminal for distance measurement using the first access and mobility management function is as follows: The first access and mobility management function obtains the identifier of the serving access and mobility management function of the at least one ranging terminal from the integrated data management; The first access and mobility management function obtains one or more candidate location management functions of the at least one ranging terminal from the network repository function based on the identifier of the serving access and mobility management function of the at least one ranging terminal; and If one or more candidate location management functions of the third terminal include a location management function for the positioning request terminal, then the third terminal is determined to be the terminal from which the distance measurement was initiated. Including, or; The step of determining the third terminal as the starting terminal for distance measurement using the first access and mobility management function is as follows: The first access and mobility management function obtains the identifier of the serving access and mobility management function of the at least one ranging terminal from the integrated data management; The first access and mobility management function obtains one or more candidate location management functions of the at least one distance measuring terminal and one or more candidate location management functions of the positioning request terminal from the network repository function based on the identifier of the serving access and mobility management function of the at least one distance measuring terminal and the identifier of the serving access and mobility management function of the positioning request terminal, where the serving access and mobility management function of the positioning request terminal is the first access and mobility management function; and If the one or more candidate location management functions of the third terminal and the one or more candidate location management functions of the positioning request terminal have common parts, the third terminal is determined to be the distance measurement initiation terminal. The method according to claim 12, including the method described in claim 12.

14. The step of obtaining one or more candidate location management functions of the at least one ranging terminal from the network repository function based on the identifier of the serving access and mobility management function of the at least one ranging terminal by the first access and mobility management function is as follows: The first location management function sends a fourth query request to the network repository function, wherein the fourth query request holds the identifier of the serving access and mobility management function of the at least one ranging terminal; and The first position management function receives a first query response transmitted by the network repository function, wherein the first query response holds one or more identifiers of the one or more candidate position management functions of the at least one ranging terminal. The method according to claim 13, including the method described in claim 13.

15. The step of determining the third terminal as the starting terminal for distance measurement using the first access and mobility management function is as follows: The first access and mobility management function obtains the identifier of the serving access and mobility management function of the at least one ranging terminal from the integrated data management; The first access and mobility management function obtains second information from the network repository function based on the identifier of the serving access and mobility management function of the at least one ranging terminal, wherein the second information indicates that one or more candidate location management functions of the third terminal include the location management function of the positioning request terminal; and The first access and mobility management function determines the third terminal as the starting terminal for distance measurement based on the second information. Including; or, The step of determining the third terminal as the starting terminal for distance measurement using the first access and mobility management function is as follows: The first access and mobility management function obtains the identifier of the serving access and mobility management function of the at least one ranging terminal from the integrated data management; In the first access and mobility management function, based on the identifier of the serving access and mobility management function of the at least one ranging terminal and the identifier of the serving access and mobility management function of the positioning request terminal, the second information is obtained from the network repository function, where the second information indicates that one or more candidate location management functions of the third terminal and one or more candidate location management functions of the positioning request terminal have a common part, and the serving access and mobility management function of the positioning request terminal is the first access and mobility management function; and The first access and mobility management function determines the third terminal as the starting terminal for distance measurement based on the second information. The method according to claim 12, including the method described in claim 12.

16. The step of obtaining second information from the network repository function based on the identifier of the serving access and mobility management function of the at least one ranging terminal using the first access and mobility management function is as follows: In the first access and mobility management function, a fifth query request is sent to the network repository function, wherein the fifth query request holds at least the identifier of the serving access and mobility management function of the at least one ranging terminal; and The first access and mobility management function receives a fifth query response transmitted by the network repository function, where the fifth query response holds the second information. The method according to claim 15, including the method described in claim 15.

17. The fifth query request holds the identifier or second instruction information of the first access and mobility management function, and the identifier or second instruction information of the first access and mobility management function is: If a distance measuring terminal that satisfies the second condition exists in at least one of the distance measuring terminals, the second information is returned, wherein one or more candidate position management functions of the distance measuring terminal that satisfies the second condition and the one or more candidate position management functions of the positioning request terminal have a common part; or, one or more candidate position management functions of the distance measuring terminal that satisfies the second condition include the position management function of the positioning request terminal, wherein the distance measuring terminal that satisfies the second condition includes the third terminal. The method according to claim 16, which provides instructions for the following.

18. The step of obtaining the identifier of the serving access and mobility management function of the at least one ranging terminal from integrated data management using the first access and mobility management function is as follows: The first access and mobility management function sends a sixth query request to the integrated data management, wherein the sixth query request holds the identifier of the at least one ranging terminal; and The first access and mobility management function receives a sixth query response transmitted by the integrated data management, wherein the sixth query response holds the identifier of the serving access and mobility management function of the at least one ranging terminal. The method according to any one of claims 13 to 17, including the method described in any one of claims 13 to 17.

19. The first network element is a first access and mobility management function; The step of instructing the distance measurement initiation terminal to start distance measurement by the first network element is: In the step where the first access and mobility management function transmits the second request to the second location management function, the second request holds the instruction information of the distance measurement initiation terminal. The method according to any one of claims 1 to 4 and 12 to 17, including the method described in any one of claims 1 to 4 and 12 to 17.

20. The method according to any one of claims 1 to 4 and 12 to 17, wherein the first network element is a first gateway mobile location center.

21. A positioning method applicable to the first gateway mobile location center, The step of receiving a first position request, where the first position request is used to request that positioning be performed based on at least one ranging terminal; and A step in which the terminal from which the distance measurement was initiated is determined based on the reachability information of the at least one distance measurement terminal, where the terminal from which the distance measurement was initiated is one of the at least one distance measurement terminals. A method that includes [a certain feature].

22. The aforementioned step of determining the terminal from which the distance measurement was initiated is: Steps to determine the starting terminal for distance measurement based on reachability information and terminal subscription information of the at least one distance measurement terminal. The method according to claim 21, including the method described in claim 21.

23. The method according to claim 21, wherein the at least one distance measuring terminal includes a first distance measuring terminal that is set to be reachable and a second distance measuring terminal that is set to be unreachable.

24. The method according to claim 21, further comprising the step of obtaining the reachability information of the at least one distance measuring terminal from integrated data management.

25. The step of obtaining the reachability information of the at least one distance measuring terminal from integrated data management is: The steps include sending a first query request containing the identifier of the first distance measuring terminal to the integrated data management system, and receiving a first query response sent by the integrated data management system, wherein the first query response contains reachability information for the first distance measuring terminal; and The process involves sending a second query request containing the identifier of the second distance measuring terminal to the integrated data management system, and receiving a second query response sent by the integrated data management system, wherein the second query response contains reachability information for the second distance measuring terminal. The method according to claim 24, including the method described in claim 24.

26. The steps include sending a query request containing the identifier of the first distance measuring terminal to the integrated data management system and receiving a query response sent by the integrated data management system, wherein the query response contains the identifiers of the serving access and mobility management functions of the first distance measuring terminal; and The process involves sending a query request containing the identifier of the second distance measuring terminal to the integrated data management system and receiving a query response sent by the integrated data management system, wherein the query response contains the identifiers of the serving access and mobility management functions of the second distance measuring terminal. The method according to any one of claims 21 to 25, further comprising:

27. The step of receiving the first position request is: In the step of receiving the first location request from the serving access and mobility management function of the positioning request terminal, the first location request holds an identifier of the at least one ranging terminal, The method according to any one of claims 21 to 25, including the method described in any one of claims 21 to 25.

28. In the step of transmitting a second location request to the first access and mobility management function, the second location request is used to request the acquisition of a distance measurement result between the distance measuring terminal and another distance measurement initiation terminal at the at least one distance measuring terminal, The method according to any one of claims 21 to 25, further comprising:

29. The method according to claim 28, wherein the second position request holds first information, the first information indicates the distance measurement initiation terminal, the first access and mobility management function is the serving access and mobility management function of the distance measurement initiation terminal, and the distance measurement initiation terminal is one of the at least one distance measurement terminals.

30. The step of receiving the distance measurement result transmitted by the serving access and mobility management functions of the distance measurement initiation terminal; and The step of transmitting the distance measurement result to the serving access and mobility management functions of the positioning request terminal. The method according to any one of claims 21 to 25, further comprising:

31. The method according to any one of claims 21 to 25, wherein the first gateway mobile location center is a gateway mobile location center that serves a positioning request terminal.

32. A communication device comprising one or more processors, wherein the one or more processors are linked to one or more memories that store one or more computer programs, and the one or more computer programs include instructions, and when the instructions are executed by the one or more processors, the communication device is capable of performing the method according to any one of claims 1 to 10 or the method according to any one of claims 12 to 17.

33. A communication device comprising one or more processors, wherein the one or more processors are linked to one or more memories for storing one or more computer programs, and the one or more computer programs include instructions, and when the instructions are executed by the one or more processors, the communication device is capable of performing the method according to any one of claims 21 to 25.

34. A computer-readable storage medium containing a computer program, wherein when the computer program is executed on an electronic device, the electronic device is capable of performing the method according to any one of claims 1 to 10 or the method according to any one of claims 12 to 17.

35. A computer-readable storage medium containing a computer program, wherein when the computer program is executed on an electronic device, the electronic device is capable of performing the method according to any one of claims 21 to 25.

36. A computer program for causing an electronic device to perform the method according to any one of claims 1 to 10, or the method according to any one of claims 12 to 17.

37. A computer program for causing an electronic device to perform the method described in any one of claims 21 to 25.

38. A chip system comprising: memory configured to store a computer program; and a processor, wherein the processor retrieves the computer program from the memory and executes the computer program, and the electronic device on which the chip system is installed performs the method according to any one of claims 1 to 10 or the method according to any one of claims 12 to 17.

39. A chip system comprising: a memory configured to store a computer program; and a processor, wherein the processor retrieves the computer program from the memory and executes the computer program, and the electronic device on which the chip system is installed performs the method according to any one of claims 21 to 25.

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