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] The present application relates to the field of communication technology, and in particular to a positioning method, device and storage medium. [Background technology]

[0002] A 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 the user based on a geographic information system.

[0003] Currently, in the process of implementing location-based services / location services, it is necessary to select a ranging initiator terminal (initiator UE) to initiate ranging with another terminal and obtain ranging information, and then perform positioning based on the ranging information. How to select an appropriate ranging initiator terminal to reduce network interaction is currently a technical problem that needs to be solved. Summary of the Invention

[0004] The embodiments of the present application provide a positioning method, apparatus and storage medium for selecting a suitable ranging terminal.

[0005] According to a first aspect, there is provided a positioning method comprising: a step of 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 step of the first network element determining a ranging initiation terminal, where the ranging initiation terminal is one of the at least one ranging terminal, and the ranging initiation terminal satisfies a first requirement; and a step of the first network element instructing the ranging initiation terminal to start ranging.

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

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

[0008] In the above implementation, since information about the ranging originating terminal (here, the first terminal) exists in the first network element, network interaction can be reduced.

[0009] For example, the first network element is the LMF of the positioning requesting terminal (referred to herein as the first LMF). Ranging terminals include a first terminal and a second terminal. Information (e.g., context information) about the first terminal exists in the first LMF, and information about the second terminal does not exist in the first LMF. In this case, the first LMF selects the first terminal as the ranging initiating terminal, so that the first LMF can send a positioning request (or a location request or a ranging request) to the first terminal and instruct the first terminal to start a ranging operation. However, in the same scenario, if the first LMF selects the second terminal as the ranging initiating terminal, the first LMF needs to send a positioning request (or a location request or a ranging request) to the LMF of the second terminal (referred to as the second LMF), and the second LMF then sends a request to the second terminal to request the second terminal to start a ranging operation. It can be seen that network interaction can be reduced by selecting the first terminal as the ranging start terminal compared to selecting the second terminal as the ranging start terminal.

[0010] In another example, the first network element is a serving AMF (herein referred to as the first AMF) of the positioning requesting terminal. The ranging terminals include a first terminal and a second terminal, and information (e.g., context information) about the first terminal exists in the first AMF, while information about the second terminal does not exist in the first AMF. In this case, the first AMF selects the first terminal as a ranging initiating terminal. Because the first AMF includes information about the first terminal, it indicates that the first AMF sends a positioning request (or a location request or a ranging request) to the LMF of the positioning requesting terminal for the first terminal, and the LMF of the positioning requesting terminal (herein referred to as the first LMF) has established context information for the first terminal. In this way, after the first AMF sends the positioning request (or a location request or a ranging request) to the first LMF, the first LMF may send a request to the first terminal and instruct the first terminal to start a ranging operation. However, in the same scenario, if the first AMF selects the second terminal as the ranging initiation terminal, after the first AMF sends a positioning request (or location request) to the first LMF, the context information of the second terminal does not exist in the first LMF, so the first LMF needs to send a positioning request (or location request or ranging request) to the LMF of the second terminal (referred to as the second LMF here), and then the second LMF sends a request to the second terminal, requesting the second terminal to start a ranging operation. It can be seen that network interaction can be reduced by selecting the first terminal as the ranging initiation terminal compared to selecting the second terminal as the ranging initiation terminal.

[0011] In a possible implementation, the first network element is a first LMF; the first network element determines the ranging initiation terminal, where the ranging initiation terminal is one of the at least one ranging terminal, and the ranging initiation terminal satisfies the first requirement, includes: if information about any one of the at least one ranging terminal is not present in the first LMF, the first LMF determines a second terminal as the ranging initiation terminal, where the second terminal is one of the at least one ranging terminal.

[0012] In a possible implementation, the first LMF determining the second terminal as a ranging initiation terminal includes: the first LMF obtaining an identifier of a serving access and mobility management function AMF of at least one ranging terminal from an integrated data management UDM; the first LMF obtaining one or more candidate LMFs of at least one ranging terminal from a network repository function NRF based on the identifier of the serving AMF of the at least one ranging terminal; and, if the one or more candidate LMFs of the second terminal include the first LMF, determining that the first LMF can be used as an LMF of the second terminal, and determining the second terminal as a ranging initiation terminal.

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

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

[0015] Optionally, the first query request further carries registration area information of 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 an identifier of a serving AMF of the at least one ranging terminal includes: the first LMF sending at least one first query request to the NRF, where the at least one first query request has a one-to-one correspondence with the at least one ranging terminal, and each first query request holds an identifier of a serving AMF of the corresponding ranging terminal; and the first LMF receiving at least one first query response sent by the NRF, where the at least one first query response has a one-to-one correspondence with the at least one ranging terminal, and each first query response holds one or more identifiers of one or more candidate LMFs of the corresponding ranging terminal.

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

[0018] In a possible implementation, the first LMF determining the second terminal as the ranging initiation terminal includes: the first LMF obtaining an identifier of a 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 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 determining the second terminal as the ranging initiation terminal based on the first information.

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

[0020] In a possible implementation, the second query request holds an identifier or first indication information of the first LMF, and the identifier or first indication information of the first LMF indicates that: if a ranging terminal that satisfies the first condition exists in at least one ranging terminal, the first LMF can be used as an 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 further carries an identifier of the first LMF.

[0022] Optionally, the second query request further carries registration area information of at least one ranging terminal.

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

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

[0025] In a possible implementation, the first LMF obtaining an identifier of a serving AMF of at least one ranging terminal from the UDM includes: the first LMF sending a third query request to the UDM, where the third query request holds an identifier of the at least one ranging terminal; and the first LMF receiving a third query response sent by the UDM, where the third query response holds an identifier of a serving AMF of the at least one ranging terminal.

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

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

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

[0029] In a possible implementation, the first network element is a first AMF; the first network element determines a ranging initiation terminal, where the ranging initiation terminal is one of the at least one ranging terminal, and the ranging initiation terminal satisfies the first requirement, which includes: if information about any one of the at least one ranging terminal does not exist in the first AMF, the first AMF determines a third terminal as a ranging initiation terminal, where the third terminal is one of the at least one ranging terminal.

[0030] In a possible implementation, the first AMF determining the third terminal as the ranging initiation terminal includes: the first AMF obtaining an identifier of a serving AMF of at least one ranging terminal from the UDM; 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 the at least one ranging terminal; and if the one or more candidate LMFs of the third terminal include the LMF of the positioning request terminal, determining the third terminal as the ranging initiation terminal. Alternatively, the first AMF determining the third terminal as a ranging initiation terminal includes: the first AMF obtaining an identifier of a serving AMF of at least one ranging terminal from the UDM; the first AMF obtaining 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 the at least one ranging terminal and the identifier of the serving AMF of the positioning request terminal, wherein 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 an intersection, determining the third terminal as a ranging initiation terminal.

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

[0032] If the first AMF does not select any LMF, one or more candidate LMFs of the third terminal used as the ranging initiation terminal and one or more candidate LMFs of the positioning requesting terminal have a common part. In this way, the first AMF can select an LMF for the positioning requesting terminal from the LMFs in the common part, and the selected LMF can also serve the third terminal. Therefore, the LMF can send a request to the third terminal used as the ranging initiation terminal, requesting it to start a ranging operation, thereby reducing network interaction.

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

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

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

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

[0037] In a possible implementation, the first AMF determining the third terminal as the ranging initiation terminal includes: the first AMF obtaining an identifier of a 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 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 determining the third terminal as the ranging initiation terminal based on the second information. Alternatively, the first AMF determining the third terminal as the ranging initiation terminal includes: the first AMF obtaining an identifier of a 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 the at least one ranging terminal and the identifier of the serving AMF of the positioning requesting 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 requesting terminal have a common portion, and the serving AMF of the positioning requesting terminal is the first AMF; and the first AMF determining the third terminal as the ranging initiation terminal based on the second information.

[0038] In a possible implementation, the first AMF obtaining the second information from the NRF 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 an identifier of the serving AMF of the 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 identifier of an AMF or second indication information, and the identifier of the first AMF or the second indication information indicates that: if a ranging terminal that satisfies the second condition exists in at least one ranging terminal, the second information is returned, where one or more candidate LMFs of the ranging terminal that satisfies the second condition and one or more candidate LMFs of the positioning request terminal have a common portion; or one or more candidate LMFs of the ranging terminal that satisfies the second condition include the LMF of the positioning request terminal, where the ranging terminal that satisfies the second condition includes a third terminal.

[0040] Optionally, the fifth query response further carries an identifier of the first AMF.

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

[0042] Optionally, the first AMF obtaining the 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 the at least one fifth query request has a one-to-one correspondence with at least one ranging terminal, and each fifth query request holds an 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 the at least one fifth query response has a one-to-one correspondence with at least one ranging terminal, and each fifth query response holds a confirmation indication, and the confirmation indication 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 portion.

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

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

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

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

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

[0048] In a possible implementation, the first network element is a first AMF, and the first network element instructing the ranging source terminal to start ranging includes: the first AMF sending a second request to the second LMF, where the second request carries instruction information of the ranging source terminal.

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

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

[0051] In a possible implementation, the first network element is a first GMLC. The method includes: receiving a first location request by the first GMLC, where the first location request is used to request performing positioning based on at least one ranging terminal; selecting a fifth terminal from the at least one ranging terminal based on reachability of the at least one ranging terminal; and sending a second location request by the first GMLC to a first AMF, where the second location request carries first information, where the first information indicates that the fifth terminal is a ranging initiator terminal, and the first AMF is a serving AMF of the fifth terminal.

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

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

[0054] According to another aspect, there is provided a communications device including one or more processors. One or more memories store one or more computer programs. The one or more computer programs include instructions. When the instructions are executed by the one or more processors, the communications device is capable of performing a method according to any possible implementation of the first aspect.

[0055] According to another aspect, there is further provided a computer-readable storage medium comprising a computer program, which when executed on an electronic device enables the electronic device to perform a method according to any possible implementation of the first aspect.

[0056] According to another aspect, there is also provided a computer program product, which, when executed on an electronic device, enables the electronic device to perform a method according to any possible implementation of the first aspect.

[0057] According to another aspect, there is provided a chip system comprising: a memory configured to store a computer program; and a processor, wherein after the processor retrieves and executes the computer program from the memory, an electronic device in which the chip system is installed is capable of executing a method according to any possible implementation of the first aspect. [Brief explanation of the drawings]

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

[0059] The following clearly and completely describes the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. The terms used in the following embodiments are only intended to describe specific embodiments and are not intended to limit the present application. The singular terms "one," "a," and "this" used in this specification and the appended claims of the present application are also intended to include expressions such as "one or more," unless otherwise clearly defined by the context. In the embodiments of the present application, "one or more" refers to one, two, or more, and "and / or" describes a relational relationship between related objects and indicates that three relationships may exist. For example, A and / or B may refer to 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 objects.

[0060] References herein to "an embodiment," "some embodiments," or the like indicate that one or more embodiments of the present application include a particular feature, structure, or characteristic described with reference to the embodiment. Thus, the phrases "in an embodiment," "in some embodiments," "in some other embodiments," and the like in various places throughout this specification do not necessarily all refer to the same embodiment, and may mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and their derivatives all mean "including, but not limited to," unless otherwise specifically emphasized.

[0061] "Plurality" in the embodiments of the present application refers to two or more. It should be noted that in describing the embodiments of the present application, terms such as "first" and "second" are merely intended as descriptive distinctions and should not be construed as indicating or suggesting relative importance or ordering.

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

[0063] The UE, (R)AN, UPF, and DN are generally referred to as data plane network function entities. User data traffic can be transmitted by using a packet data unit session (PDU session) established between the UE and the DN, and the transmission passes through two network function entities: the (R)AN and the UPF. The other part is referred to as a control plane network function entity, which mainly performs functions such as authentication and authorization, registration management, session management, mobility management, and policy control, and implements 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 service-based 5G system architecture and non-roaming reference point-based architecture, the functions of network elements relevant to this application are as follows:

[0065] Terminal device: A terminal device may be a UE, handheld terminal, notebook computer, subscriber unit, cellular phone, smartphone, wireless data card, personal digital assistant (PDA) computer, tablet computer, wireless modem, handheld device, augmented reality (AR) device, virtual reality (VR) device, laptop computer, cordless phone or wireless local loop (WLL) station, machine type communication (MTC) terminal, or another device capable of accessing a network. Terminal devices and access network devices communicate with each other by using an air interface technology (e.g., new radio (NR) or long term evolution (LTE) technology). Terminal devices may also communicate with each other by using an air interface technology (e.g., NR technology or LTE technology). In Internet of Vehicles communication, a communication terminal mounted on a vehicle is a terminal device, and a road side unit (RSU) can also be used as a terminal device. A communication terminal mounted on a drone can also be considered as a terminal device.

[0066] (R)AN device: An (R)AN device is a device that provides access for a terminal device and includes a RAN device and an AN device. RAN devices are mainly 3GPP (registered trademark) network radio network devices, while AN devices may be non-3GPP-defined access network devices. Radio access network (RAN) devices mainly 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 types 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 a RAN or gNB (5G NodeB) in a 5th generation (5G) system, an evolved NodeB (eNB or eNodeB) in an LTE system, and a NodeB in a 3rd generation (3G) system.

[0067] Access network device: This network element enables interconnection and interworking between terminal devices and the 3GPP core network by using non-3GPP technologies, such as wireless fidelity (Wi-Fi®), worldwide interoperability for microwave access (WiMAX®), or code division multiple access (CDMA) networks.

[0068] AMF network element: An AMF network element is a core network element, and is mainly responsible for functions such as signaling processing, e.g., access control, mobility management, attachment and detachment, and gateway selection. When providing a service for a session in a terminal device, the AMF network element provides control plane storage resources for the session to store a session identifier, an SMF network element identifier associated with the session identifier, and the like.

[0069] SMF network element: The SMF network element is mainly responsible for session management in a mobile network, such as user plane network element selection, user plane network element redirection, internet protocol (IP) address allocation, bearer establishment, modification and release, and QoS control.

[0070] UPF network element: The UPF network element is responsible for forwarding and receiving user data at a terminal device. The UPF network element may receive user data from a data network and transmit the user data to a terminal device through an access network device. The UPF network element may also receive user data from a terminal device through an access network device and forward the user data to a data network. The transmission resources and scheduling functions used by the UPF network element to provide services to terminal devices are managed and controlled by the SMF network element.

[0071] PCF Network Element: The PCF network element is mainly responsible for providing policy control decisions, providing policy rules for controlling plane functions, and providing traffic-based charging control functions.

[0072] Network Exposure Function (NEF) Network Element: The Network Exposure Function network element primarily supports secure interactions between 3GPP networks and third-party applications.

[0073] AF Network Element: The AF network element mainly supports interacting with the 3GPP core network to provide services, for example, influencing data routing decisions and policy control functions, or providing some third-party services to the network side. If the AF and 5G systems are in different trust domains, input can be provided through the NEF application programming interface (API). If the AF and 5G systems are in the same trust domain, input can be provided directly by using the Time Sensitive communication Time Synchronization function (TSCTSF). In 5G, the application function network element may be, for example, an AF network element as shown in FIG. 1 or FIG. 2. In future communications, for example, 6G, the application function network element may still be an AF network element or may have a different name. This is not a limitation in this application.

[0074] Unified Data Management (UDM) Network Element: A unified data management network element is configured to generate authentication credentials, handle user identifiers (e.g., store and manage users' permanent identities), control access authorization, manage subscription data, etc.

[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 element: The NSSF network element is mainly responsible for selecting a network slice and determining the instance of the network slice accessible by the UE based on the UE's slice selection assistance information, subscription information, and the like.

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

[0078] Network Repository Function (NRF) Network Element: The Network Repository Function Network Element supports registration and discovery of network functions.

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

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

[0081] In the above architecture, 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 a virtualization function on an appropriate platform, for example, a cloud platform.

[0082] In this application, a network element may also be referred to as a network function, a function, an entity, or the like, which is not limited in this application.

[0083] The distributed form of the network elements is not limited in the embodiments of the present application. The distributed form shown in Fig. 1 is merely an example and is not limited in the present application. The communication system architecture shown in Fig. 1 or 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 will not be described one by one here in the present application.

[0084] For ease of explanation, the network elements shown in FIG. 1 are used later in this application as examples for explanation, and the XX network element is simply referred to as XX. It should be understood that the names of all network elements in the embodiments of this application are used merely as examples, and may be referred to by other names in future communications, or the network elements in the embodiments of this application may be replaced by other entities, devices, or similar entities with the same functions in future communications. This is not limited in the embodiments of this application. An integrated description is provided here, and the details will not be described again below.

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

[0086] 3 shows a positioning system architecture based on a 5G system (5GS) according to an embodiment of the present application. 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 location estimates based on ranging information (also referred to as positioning measurements) collected by the UE and the NG-RAN, and manage the coordination and scheduling of positioning resources.

[0088] UDM: The UDM is configured to store a UE location privacy configuration profile that may indicate whether the UE allows another client or AF to obtain location information of the UE.

[0089] NEF Network Element: The NEF network element is configured to provide a method for accessing location-based services by using external / internal AFs or clients.

[0090] Gateway Mobile Location Center (GMLC): The Gateway Mobile Location Center provides a method for accessing location-based services by using external / internal AFs or clients and is configured to perform charging.

[0091] RAN / UE: The RAN / UE is configured to collect positioning measurements or parameters of the LMF and calculate a position estimate.

[0092] AMF Network Element: The AMF network element is 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: The UE 3 triggers a service request. The UE 3 is 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, sends a ranging request or a service location (SL) request (hereinafter referred to as an SL request) to the AMF through an uplink NAS transmission, and sends the identifiers of UE1 and UE2 (UE1 ID and UE2 ID) to the AMF. UE1 and UE2 are ranging terminals.

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

[0097] Step 404: The AMF sends a ranging request or a 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 initiator for starting the ranging operation on the PC5 interface, i.e., selects UE2 as the ranging initiator terminal (initiating UE), and sends a ranging request or SL positioning request to UE2.

[0099] Step 406: UE2 initiates a ranging operation between UE1 and UE2 based on the received ranging request or SL positioning request.

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

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

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

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

[0104] In the above procedure, there is currently no effective solution for how the LMF selects the ranging source terminal. A possible solution is to randomly select a terminal from UE1 and UE2 as the ranging source terminal. Since the serving AMF or LMF of the ranging terminals (UE1 and UE2) and the positioning requesting terminal (UE3) may be different, the different AMFs or LMFs may exchange information, which may affect the 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 Fig. 3 or an evolved version of the positioning system architecture. According to some embodiments of the present application, an appropriate ranging originating terminal may be selected to reduce interactions between network elements, thereby reducing complexity, reducing delay, and improving positioning efficiency.

[0106] With reference to the accompanying drawings, the following describes methods and apparatuses provided in embodiments of the present application.

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

[0108] S501: A first network element receives a first request, where the first request is used to request to perform positioning based on at least one ranging terminal.

[0109] Optionally, the first request may be a SL positioning request, a ranging request, a location request, or other signaling that can be used to implement a positioning or ranging request, which is not limited in this embodiment of the present application.

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

[0111] A ranging terminal can be understood to be a target UE configured to perform SL ranging, and a positioning requesting terminal can be understood to be a terminal consuming an LCS service.

[0112] In a possible implementation, the first request may be from a positioning requesting terminal, for example, the positioning requesting terminal sends the first request, and the first request is sent to the first network element through an associated network element (e.g., a RAN, a serving AMF of the RAN, or a serving AMF of the terminal).

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

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

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

[0116] 6, the second network element is used to represent the network element from which the first request originates. According to the above description, 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 an LMF, the second network element is an AMF; when the first network element is an AMF, the second network element is a RAN (or a UE, e.g., the UE sends the first request by using a NAS message), or the second network element is a GMLC; or when the first network element is a GMLC, the second network element is an NEF or an AMF.

[0117] S502: A first network element determines 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.

[0118] In a possible implementation, the first network element may determine a first terminal in at least one ranging terminal as a ranging initiation terminal, where 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 positioning context information or ranging context information of the first terminal. In other words, if information about the first terminal in the ranging terminal (positioning context information or ranging context information of the terminal) exists in the first network element, the first network element may determine the first terminal as a ranging initiation terminal.

[0119] In a scenario of two ranging terminals (UE1 and UE2), if the AMF is UE1 that initiates 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 a positioning requesting terminal, where the positioning requesting terminal is represented as UE3, and the ranging terminals include UE1 and UE2, where the LMF of UE3 is represented as LMF3, where the positioning context information of UE1 is present in LMF3, and the positioning context information of UE2 is not present in LMF3. If UE1 is selected as the ranging initiating terminal, LMF3 may send a ranging request or an SL positioning request to UE1 to request UE1 to perform a ranging operation and receive the ranging result returned by UE1. If UE2 is selected as the ranging initiating terminal, LMF3 needs to send a ranging request or an SL positioning request to the LMF of UE2 (represented as LMF2). Then, LMF2 sends a ranging request or an SL positioning request to UE2 to request UE2 to perform a ranging operation, where UE2 sends the ranging result to LMF2, and LMF2 sends the ranging result to LMF3. In addition, the interaction between LMF3 and LMF2 may further need to pass through multiple intermediate network elements, such as GMLC and AMF. It can be seen that, compared with selecting UE2 as the ranging initiation terminal, selecting UE1, which satisfies the first requirement in this embodiment of the present application, as the ranging initiation terminal can reduce network interaction operations.

[0121] Optionally, if information about multiple ranging terminals exists in the first network element, the first network element may randomly select one of the multiple ranging terminals as a ranging initiation terminal, or may perform selection according to another criterion (for example, according to terminal subscription information or UE reachability), which is not limited in this embodiment of the present application.

[0122] In another example, the first network element is a serving AMF of a positioning requesting terminal, where the positioning requesting terminal is represented as UE3, and the ranging terminals include UE1 and UE2, where the LMF of UE3 is represented as LMF3, and the serving AMF of UE3 is represented as AMF3, where context information of UE1 exists in AMF3, and positioning context information of UE2 does not exist in AMF3. When AMF3 selects UE1 as a ranging initiating terminal, AMF3 includes positioning context information of UE1, which indicates that AMF3 sends a positioning request (position request or ranging request) for UE1 to LMF3, and that positioning context information for UE1 has been established in LMF3. In this way, after AMF3 sends the positioning request (or position request or ranging request) to LMF3, LMF3 may send a request to UE1 to instruct the first terminal to initiate a ranging operation. However, in the same scenario, if AMF3 selects UE2 as the ranging initiator terminal, after AMF3 sends a positioning request (or location request or ranging request) to LMF3, since the positioning context information of UE2 does not exist in LMF3, LMF3 needs to send a request to the LMF of UE2 (referred to as LMF2 here), and then LMF2 sends a request to UE2, requesting the second terminal to initiate the ranging operation. In addition, the interaction between LMF3 and LMF2 may further need to pass through multiple intermediate network elements, such as GMLC and AMF. Similarly, there are also the above-mentioned differences in the transmission path of the ranging result. It can be seen that selecting UE1 as the ranging initiator terminal can reduce network interactions compared to selecting UE2 as the ranging initiator terminal.

[0123] In a possible implementation, the first network element is a first LMF. Optionally, the first LMF is an LMF of a positioning requesting terminal. In this case, if information about any one of the at least one ranging terminal does not exist in the first LMF, the first LMF determines a second terminal in the at least one ranging terminal as a ranging initiating terminal.

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

[0125] Optionally, if multiple ranging terminals meet the above requirements, the first LMF may randomly select one of the multiple ranging terminals as a ranging initiation terminal, or may perform selection according to another criterion (for example, according to terminal subscription information or UE reachability), which is not limited in this embodiment of the present application.

[0126] In a possible implementation, the first LMF may acquire one or more candidate LMFs of the ranging terminal by interacting with the UDM and the NRF, and select the second terminal as a ranging initiation terminal based on the one or more candidate LMFs of the ranging terminal. The process may include the following steps: the first LMF acquires an identifier of a serving AMF of each ranging terminal from the UDM, and acquires one or more candidate LMFs of each ranging terminal from the NRF based on the identifier of the serving AMF of each ranging terminal; and if the one or more candidate LMFs of the second terminal include the first LMF, it is determined that the first LMF can be used as the LMF of the second terminal, and the first LMF determines the second terminal as a ranging initiation terminal.

[0127] Optionally, a possible interaction process 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 carries an identifier of at least one serving AMF of the ranging terminal; and the NRF sending a first query response to the first LMF, where the first query response carries one or more identifiers of one or more candidate LMFs of the ranging terminal. Optionally, the first query request further carries 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 (N is an integer greater than or equal to 1, and N is the number of ranging terminals) first query requests to the NRF. The N first query requests have a one-to-one correspondence with the N ranging terminals, and each first query request holds an identifier of a serving AMF of the corresponding ranging terminal. For example, the first LMF sends a first query request to the NRF to request to query one or more identifiers of one or more candidate LMFs of ranging terminal 1; the first LMF sends a first query request to the NRF a second time to request to query one or more identifiers of one or more candidate LMFs of ranging terminal 2; the rest can be inferred by analogy. The NRF separately sends N first query responses. The N first query responses are in one-to-one correspondence with the N ranging terminals, and each first query response carries one or more identifiers of one or more candidate LMFs of the corresponding ranging terminal. Optionally, each first query response further carries registration area information of the corresponding ranging terminal.

[0129] In another possible implementation, the first LMF may acquire one or more candidate LMFs of the ranging terminal by interacting with the UDM and the NRF, and select the second terminal as a ranging initiation terminal based on the one or more candidate LMFs of the ranging terminal. The process may include the following steps: the first LMF acquires an identifier of a serving AMF of each ranging terminal from the UDM, and acquires first information from the NRF based on the identifier of the serving AMF of each ranging terminal, where 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 a ranging initiation terminal based on the first information. In the above process, the NRF may acquire one or more candidate LMFs of each ranging terminal based on the identifier of the serving AMF of the ranging terminal. If one or more candidate LMFs of the second terminal include the first LMF, first information is sent to the first LMF indicating that one or more candidate LMFs of the second terminal include the first LMF or indicating that the first LMF can be used as an LMF of the second terminal.

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

[0131] Optionally, the second query request may carry an identifier of the first LMF or first indication information, where the identifier of the first LMF or the first indication information indicates that: if a ranging terminal that satisfies a first condition exists in the ranging terminal, a first message is returned. The one or more candidate LMFs of the ranging terminal that satisfy the first condition include the first LMF.

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

[0134] Optionally, the second query request may further carry registration area information of the ranging terminal.

[0135] Optionally, another possible interaction process between the first LMF and the NRF may include: the first LMF sending N (N is the number of ranging terminals) second query requests to the NRF, where the N second query requests are in one-to-one correspondence with the N ranging terminals, and each second query request holding an identifier of a serving AMF of the corresponding ranging terminal; and the NRF sending N second query responses to the first LMF, where the N second query responses are in one-to-one correspondence with the N ranging terminals, and each second query response holding a confirmation indication, where the confirmation indication indicates whether the first LMF can be used as an 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 of the first LMF interacting with the UDM to obtain the identifier of the serving AMF of the ranging terminal may include: the first LMF sending a third query request to the UDM, where the third query request holds the identifier of each ranging terminal; the UDM sending a third query response to the first LMF, where the third query response holds the identifier of the serving AMF of each ranging terminal. Optionally, the third query response further holds registration area information of the ranging terminal.

[0137] In another possible implementation, the process of the first LMF interacting with the UDM to obtain an identifier of a serving AMF of a ranging terminal may include: the first LMF sending N (N is the number of ranging terminals) third query requests to the UDM, where the N third query requests are in a one-to-one correspondence with the N ranging terminals, and each third query request holds an identifier of the corresponding ranging terminal; and the UDM sending N third query responses to the first LMF, where the N third query responses are in a one-to-one correspondence with the N ranging terminals, and each third query response holds an 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 a possible implementation, the first network element is a first AMF. Optionally, the first AMF is a serving AMF of the positioning requesting terminal. In this case, if the first AMF does not have information (e.g., positioning context information or ranging context information) about any one of the at least one ranging terminal, the first AMF determines a third terminal in the at least one ranging terminal as a ranging initiation terminal.

[0139] Optionally, the third terminal meets 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] By selecting a terminal that satisfies the above conditions as a ranging initiation terminal, network interaction operations can be reduced. For example, a positioning requesting terminal is represented as UE3, ranging terminals include UE1 and UE2, a serving AMF of UE3 is represented as AMF3, AMF3 has selected an LMF (represented as LMF3) of the positioning requesting terminal, one or more candidate LMFs of UE1 include LMF3, and one or more candidate LMFs of UE2 do not include LMF3. If AMF3 selects UE1 as a ranging initiation terminal, a ranging request, an SL positioning request, or a location request may be sent to LMF3, so that LMF3 sends the ranging request, SL positioning request, or location request to UE1 to request UE1 to perform a ranging operation and receives the ranging result returned by UE1. If AMF3 selects UE2 as the ranging source terminal, a ranging request, SL positioning request, or location request needs to be sent to the serving AMF of UE2 (represented as AMF2), and then AMF2 sends the ranging request, SL positioning request, or location request to the LMF of UE2 (represented as LM2). Then, LMF2 sends the ranging request, SL positioning request, or location request to UE2, requesting UE2 to perform a ranging operation. UE2 sends the ranging result to LMF2, and then LMF2 sends the ranging result to AMF3, and AMF3 sends the ranging result to LMF3. It can be seen that, compared to selecting UE2 as the ranging source terminal, selecting UE1, which satisfies the first requirement, as the ranging source terminal in this embodiment of the present application can reduce network interaction operations.

[0142] Optionally, if multiple ranging terminals meet the above requirements, the first AMF may randomly select one of the multiple ranging terminals as a ranging initiation terminal, or may perform selection according to another criterion (for example, according to terminal subscription information or UE reachability), which is not limited in this embodiment of the present application.

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

[0144] Since one or more candidate LMFs of the third terminal and one or more candidate LMFs of the positioning requesting terminal have a common portion, the first AMF can select the same LMF for the positioning requesting terminal and the ranging initiating terminal (e.g., select an LMF from the common portion), thereby reducing network interaction operations.

[0145] Optionally, if multiple ranging terminals meet the above requirements, the first AMF may randomly select one of the multiple ranging terminals as a ranging initiation terminal, or may perform selection according to another criterion (for example, according to terminal subscription information or UE reachability), which is not limited in this embodiment of the present application.

[0146] In a possible implementation, when the first AMF selects the LMF of the positioning requesting terminal, the first AMF may select the ranging initiation terminal in the following manner: the first AMF obtains the identifier of the serving AMF of 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 of each ranging terminal; if the one or more candidate LMFs of the third terminal include the LMF of the positioning requesting terminal selected by the first AMF, the first AMF determines the third terminal as the ranging initiation terminal.

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

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

[0149] Optionally, another possible interaction process between the first AMF and the NRF may include: the first AMF sending N fourth query requests to the NRF, where the N fourth query requests are in a one-to-one correspondence with the N ranging terminals, and each fourth query request holds an identifier of a serving AMF of the corresponding ranging terminal; and the NRF sending N fourth query responses to the first AMF, where the N fourth query responses are in a one-to-one correspondence with the N ranging terminals, and each first query response holds one or more identifiers 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, when the first AMF selects the LMF of the positioning requesting terminal, the first AMF may select the ranging initiation terminal in the following manner: the first AMF obtains an identifier of the serving AMF of each ranging terminal from the UDM, and obtains second information from the NRF based on the identifier of the serving AMF of each ranging terminal, where the second information indicates that one or more candidate LMFs of the third terminal include the LMF of the positioning requesting terminal; and the first AMF determines the third terminal as the ranging initiation terminal based on the second information.

[0151] In another possible implementation, if the first AMF does not select an LMF of the positioning requesting terminal, the first AMF may select a ranging initiation terminal in the following manner: the first AMF obtains an identifier of a serving AMF of each ranging terminal from the UDM, and obtains second information from the NRF based on the identifier of the serving AMF of each ranging terminal and the identifier of the serving AMF of the positioning requesting terminal (where the serving AMF of the positioning requesting 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 requesting terminal have a common portion; and the first AMF determines the third terminal as a ranging initiation terminal based on the second information.

[0152] Optionally, a possible interaction process between the first AMF and the NRF may include: the first AMF sending a fifth query request to the NRF, where the fifth query request carries identifiers of serving AMFs of at least N (N is the number of ranging terminals) ranging terminals; and the NRF sending a fifth query response to the first AMF, where the fifth query response carries the second information. Optionally, the fifth query response may further carry an identifier of the first AMF. Optionally, the fifth query request may further carry registration area information of the ranging terminals.

[0153] Optionally, the fifth query request may carry an identifier of the first AMF or second indication information, where the identifier of the first AMF or the second indication information indicates that if a ranging terminal that satisfies the second condition exists in the ranging terminal, the second information is returned. One or more candidate LMFs of the ranging terminal that satisfy the second condition and one or more candidate LMFs of the positioning request terminal have a common portion, or one or more candidate LMFs of the ranging terminal that satisfy the second condition include the LMF of the positioning request terminal.

[0154] Optionally, another possible interaction process between the first AMF and the NRF may include: the first AMF sending N (N is the number of ranging terminals) fifth query requests to the NRF, where the N fifth query requests are in a one-to-one correspondence with the N ranging terminals, and each fifth query request holding an identifier of a serving AMF of the corresponding ranging terminal and, optionally, an identifier of the first AMF; and the NRF sending N fifth query responses to the first AMF, where the N fifth query responses are in a one-to-one correspondence with at least one ranging terminal, and each fifth query response holding a confirmation indication, where the confirmation indication 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 portion. Optionally, each fifth query request may further hold registration area information of the corresponding ranging terminal.

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

[0156] In another possible implementation, a process in which the first AMF obtains an identifier of a serving AMF of at least one ranging terminal from the UDM may include: the first AMF sending N sixth query requests to the UDM, where the N sixth query requests are in a one-to-one correspondence with the N ranging terminals, and each sixth query request holds an identifier of the corresponding ranging terminal; and the UDM sending N sixth query responses to the first AMF, where the N sixth query responses are in a one-to-one correspondence with at least one ranging terminal, and each sixth query response holds an 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 a first GMLC. Optionally, the first GMLC is a GMLC of a positioning requesting terminal. In this case, the first GMLC receives a first request, where the first request is used to request performing positioning based on at least one ranging terminal; the first GMLC selects a fifth terminal from the at least one ranging terminal based on the reachability of the at least one ranging terminal; and the first GMLC sends a second request to a first AMF (e.g., a serving AMF of the fifth terminal), where the second request carries third information, and the third information indicates that the fifth terminal is a ranging initiator terminal, so that the first AMF sends a request to an LMF of the first terminal, where the LMF requests the fifth terminal to start a ranging operation with another ranging terminal.

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

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

[0160] S503: The first network element instructs the ranging start terminal to start ranging.

[0161] In a possible implementation, if the first network element is a first LMF (e.g., an LMF of a positioning request terminal), in S503, the first LMF may send a ranging request or an SL positioning request to the ranging initiation terminal, so that the ranging initiation terminal initiates a ranging operation between the ranging terminals, for example, initiates a ranging operation on a PC5 interface. The ranging initiation terminal obtains a ranging result based on the ranging operation and transmits the ranging result to the first LMF. Furthermore, the first LMF may further transmit the ranging result to the ranging initiation terminal or the AF (through an associated network element).

[0162] In another possible implementation, if the first network element is a first AMF (e.g., a serving AMF of the positioning requesting terminal), in S503, the first AMF sends a second request to the first LMF (e.g., the LMF of the positioning requesting terminal), where the second request carries indication information of the ranging source terminal. After receiving the second request, the first LMF sends a ranging request or an SL positioning request to the ranging source terminal, so that the ranging source terminal initiates a ranging operation between the terminals based on the ranging request or the SL positioning request, for example, initiates the ranging operation over the PC5 interface. The ranging source terminal obtains a ranging result based on the ranging operation and transmits the ranging result to the first LMF. Furthermore, the first LMF may further transmit the ranging result to the ranging source terminal or the AF (through an associated network element).

[0163] Optionally, the ranging 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 ranging result or positioning result) based on the measurement information, and further transmit the measurement result (also referred to as ranging result or positioning result) to the positioning requesting terminal or the AF.

[0164] In another possible implementation, if the first network element is a first GMLC, in S503, the first GMLC sends a location request to the serving AMF of the ranging source terminal, where the location request holds indication information of the ranging source terminal. The serving AMF of the ranging source terminal sends a location request to the LMF of the ranging source terminal, where the location request holds indication information of the ranging source terminal. The LMF sends a ranging request or an SL positioning request to the ranging source terminal, whereby the ranging source terminal starts a ranging operation between the ranging source terminal and the ranging source terminal, for example, starts the ranging operation over the PC5 interface. The ranging source terminal obtains a ranging result based on the ranging operation and sends the ranging result to the LMF. Furthermore, the LMF may further send the ranging result to the first GMLC, and the first GMLC sends the ranging result to the ranging source terminal or the AF (through an associated network element).

[0165] In another embodiment of the present application, when the first network element is a first AMF (e.g., a serving AMF for a positioning request) and no terminals satisfying the first requirement exist among the ranging terminals (e.g., there is no context information of any ranging terminals in all first AMFs, or there is no context information of any ranging terminals in the first AMFs, and the first AMF cannot select the same LMF for the positioning request terminal and the ranging source terminal (e.g., one or more candidate terminals of the positioning request terminal do not include one or more candidate LMFs of the ranging source terminal, or one or more candidate LMFs of the positioning request terminal and one or more candidate LMFs of the ranging source terminal have no common part)), the first AMF may select any one of the ranging terminals (e.g., a fourth terminal) as the ranging terminal. Then, a third request (e.g., a location request) may be sent to the first GMLC (i.e., the GMLC of the ranging source terminal), and the third request carries indication information of the ranging source terminal. After receiving the third request, the first GMLC sends a location request to the LMF of the ranging initiation terminal by using the serving AMF of the ranging initiation terminal, and the LMF sends a ranging request or an SL positioning request to the ranging initiation terminal, so that the ranging initiation terminal initiates a ranging operation between the ranging initiation terminal and the ranging terminal, for example, initiates the ranging operation over the PC5 interface. The ranging initiation terminal obtains a ranging result based on the ranging operation and transmits the ranging result to the LMF. The LMF determines the SL positioning result. Then, the LMF transmits the positioning result to the first GMLC by using the serving AMF of the ranging initiation terminal. Furthermore, the first GMLC may transmit the positioning result to the positioning request terminal or the AF (through an associated network element).

[0166] In a possible implementation, when the first AMF randomly selects a terminal, for example, the fourth terminal, as a ranging initiation terminal from the ranging terminal, the first AMF may obtain an identifier of the serving AMF of the fourth terminal from the UDM and send a request (fourth request) to the serving AMF of the fourth terminal based on the identifier of the serving AMF of the fourth terminal, where the request holds indication information indicating that the fourth terminal is the ranging initiation terminal. Next, the serving AMF of the fourth terminal sends a positioning request to the LMF of the fourth terminal, where the positioning request holds indication information indicating that the fourth terminal is the ranging initiation terminal. The LMF sends a ranging request or an SL positioning request to the fourth terminal serving as the ranging initiation terminal, so that the ranging initiation terminal starts a ranging operation between the ranging terminal and the fourth terminal, for example, starts a ranging operation on the PC5 interface. The ranging initiation terminal obtains a ranging result based on the ranging operation and sends the ranging result to the LMF. The LMF determines the SL positioning result based on the ranging result, and may further transmit the SL positioning result to the positioning requesting terminal or the AF.

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

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

[0169] 7A, 7B, and 7C are diagrams of an information exchange procedure in a first example according to an embodiment of the present application. In the first example, the positioning requesting 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 transparently transmitted to LMF3 as a container. Since the container is invisible to the AMF, LMF3 selects a ranging initiating terminal. As shown in the figures, the procedure may include the following steps:

[0170] Step 701a: AF triggers a ranging requirement.

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

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

[0173] Step 701b: UE3 triggers a ranging requirement.

[0174] Optionally, UE3 sends a location request to AMF3 by using a NAS message to request an SL ranging service. The location request holds a container. The container includes identifiers (UE1 ID and UE2 ID) of ranging terminals UE1 and UE2. Furthermore, the container may further include information such as SL ranging service type, measurement type, and SL ranging requirement.

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

[0176] Step 702: The AMF 3 selects the LMF 3 for the positioning requesting terminal UE 3.

[0177] Since the positioning-related information is transmitted in a container mode, the UE1 ID and the UE2 ID are invisible to the AMF3, and the AMF3 cannot select the ranging-initiating terminal from the UE1 and the UE2. Therefore, the LMF selects the ranging-initiating terminal, and the AMF3 selects the LMF (e.g., LMF3 in this example) for the UE3.

[0178] Step 703: The AMF 3 sends a positioning request to the LMF 3, where the positioning request carries the container.

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

[0180] In this example, if the context information of UE1 exists in LMF3 but the context information of UE2 does not exist in LMF3, step 705 is executed; or if the context information of UE1 and the context information of UE2 do not exist in LMF3, step 706 is executed.

[0181] Step 705: The LMF 3 selects the UE 1 as the ranging start terminal.

[0182] In this step, an example is used in which the context information of UE1 exists in LMF3. If the context information of UE2 exists in LMF3 but the context information of UE1 does not exist in LMF3, LMF3 selects UE2 as the ranging source terminal. If the context information of UE1 and the context information of UE2 exist in LMF3, LMF3 can select UE1 or UE2 as the ranging source terminal.

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

[0184] In this step, LMF3 may use UDM to interact with the NRF to obtain candidate LMFs for UE1 and UE2, and thereby determine 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 to 706e.

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

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

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

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

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

[0190] In a possible alternative solution of steps 706c to 706d, LMF3 sends a query request 1 to the NRF, which carries an identifier of a serving AMF for UE1, and receives a query response 1 returned by the NRF, which carries identifiers of candidate LMFs for UE1. Optionally, query request 1 may further include registration area information for UE1. LMF3 sends a query request 2 to the NRF, which carries identifiers of serving AMFs for UE2, and receives a query response 2 returned by the NRF, which carries identifiers of candidate LMFs for UE2. Optionally, query request 2 may further include registration area information for UE2.

[0191] In another possible alternative solution of steps 706c to 706d, LMF3 sends a query request to the NRF, requesting to determine whether LMF3 can serve UE1 or UE2 or whether LMF3 can be used as an LMF for UE1 or UE2. The query request may carry UE1 AMF ID and UE2 AMF ID, may further carry UE1 registration area information and UE2 registration area information, and may further carry information such as LMF type information. The NRF returns a query response to LMF3, where the query response includes first information. If one or more candidate LMFs for UE1 include LMF3, the first information may include an identifier of UE1 and, optionally, may further include a confirmation indication. After receiving the first information, LMF3 uses UE1 as a ranging initiation terminal. If one or more candidate LMFs for UE2 include LMF3, the first information may include an identifier of UE2 and, optionally, may further include a confirmation indication. After receiving the first information, LMF3 uses UE2 as a ranging initiation terminal. 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 ranging terminal as a ranging initiation terminal based on the identifier of the UE included in the first information.

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

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

[0194] It should be noted that when LMF3 receives identifiers of candidate LMFs of UE1 and UE2, LMF3 determines whether one or more candidate LMFs of UE1 or UE2 include LMF3 based on the identifiers of the candidate LMFs of UE1 and UE2. When LMF3 receives first information, LMF3 may directly determine whether one or more candidate LMFs of UE1 or UE2 include LMF3 based on the first information.

[0195] Step 707: The LMF3 selects the UE1 as the ranging start terminal, and proceeds to step 708.

[0196] In this step, an example is used in which one or more candidate LMFs of UE1 include LMF3. If one or more candidate LMFs of UE2 include LMF3, LMF3 selects UE2 as the ranging source terminal. If the candidate LMFs of both UE1 and UE2 include LMF3, LMF3 can select UE1 or UE2 as the ranging source terminal.

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

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

[0199] Step 709: As the ranging requester, the LMF3 instructs the ranging initiator terminal to perform the ranging operation by using the GMLC, and then proceeds to step 710.

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

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

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

[0203] Step 709c: LMF1 starts to perform ranging between UE1 and UE2. The process may involve LMF1, AMF1, UE1 and UE2, and may optionally further involve the RAN.

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

[0205] Step 709e: AMF1 returns the ranging result to LMF3 by using GMLC1.

[0206] Step 710: The LMF3 sends a positioning response to the AMF3, where the positioning response may carry the ranging result.

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

[0208] Step 711b: If ranging is triggered by the UE 3 (see step 701b), the AMF 3 sends the ranging result to the UE 3. For example, the ranging result can be sent to the UE 3 by using a downlink NAS message.

[0209] The above is explained by using three terminals as an example. In a scenario with two terminals, the LMF may also select a ranging initiation terminal based on the principles of the above procedure. In this scenario, the LMF may select the positioning request terminal as the ranging initiation terminal. In a scenario with more than two ranging terminals, the LMF may also select a ranging initiation terminal based on the principles of the above procedure.

[0210] 8A, 8B, and 8C are diagrams of information exchange procedures in a second example according to an embodiment of the present application. In the second example, the positioning requesting 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 requirements are visible to the AMF, the AMF selects a ranging initiating terminal. As shown in the figures, the procedure may include the following steps:

[0211] Step 801a: AF triggers a ranging requirement.

[0212] Optionally, the AF requests an SL ranging service by sending a location request to the AMF 3. The location request carries identifiers of ranging terminals UE1 and UE2 (UE1 ID and UE2 ID), and may optionally further carry an identifier of positioning request terminal UE3 (UE3 ID), and may further carry information such as SL ranging service type, measurement type, and SL ranging requirement.

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

[0214] Step 801b: UE3 triggers a ranging requirement.

[0215] Optionally, UE3 sends a location request to AMF3 by using a NAS message to request an SL ranging service. The location request may carry identifiers (UE1 ID and UE2 ID) of ranging terminals UE1 and UE2, and may further carry information such as 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 the AF or the UE3.

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

[0218] Since the positioning related information is not transmitted in the container mode, the positioning related information is visible to the AMF 3. Therefore, the AMF 3 can select the ranging source terminal.

[0219] In this example, if the context information of UE1 exists in AMF3 but the context information of UE2 does not exist in AMF3, step 803 is executed; or if the context information of UE1 and the context information of UE2 do not exist in AMF3, step 804 is executed.

[0220] Step 803: AMF3 selects UE1 as the ranging start terminal.

[0221] In this step, an example is used in which the context information of UE1 exists in AMF3. 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 terminal. If the context information of UE1 and the context information of UE2 exist in AMF3, AMF3 can select UE1 or UE2 as the ranging start terminal.

[0222] Step 804: AMF3 determines whether the same LMF can be selected for UE3 and one of UE1 and UE2, and if the same LMF can be selected for UE3 and one of UE1 and UE2, proceed to step 805; or if the same LMF cannot be selected for UE3 and one of UE1 and UE2, proceed to step 807.

[0223] In this step, AMF3 may interact with the NRF by using UDM to obtain candidate LMFs for UE1 and UE2, and thereby determine whether AMF3 can select the same LMF for UE3 and one of UE1 and 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 carry UE1 ID and UE2 ID, requesting the identifiers of the serving AMFs of UE1 and UE2.

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

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

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

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

[0229] In a possible alternative solution of steps 804c to 804d, AMF3 sends a query request 1 to the NRF, which carries an identifier of a serving AMF for UE1, and receives a query response 1 returned by the NRF, which carries identifiers of candidate LMFs for UE1. Optionally, query request 1 may further include registration area information of UE1. AMF3 sends a query request 2 to the NRF, which carries identifiers of serving AMFs for UE2, and receives a query response 2 returned by the NRF, which carries identifiers of candidate LMFs for UE2. Optionally, query request 2 may further include registration area information of UE2.

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

[0231] Optionally, the identifier of the AMF3 in the query request is optional. In some scenarios, since the positioning request is from the AMF3, the LMF may recognize by default that the intersection of the candidate LMFs of the ranging terminal and the positioning requesting terminal is to be queried, and may automatically obtain the AMF3 ID.

[0232] In another possible alternative solution of steps 804c to 804d, the AMF3 sends a query request 1 to the NRF, which carries the serving AMF of UE1. Optionally, the query request 1 may further carry information such as registration area information and LMF type information of UE1. The NRF returns a query response 1 to the AMF3. The query response 1 includes second information indicating whether the one or more candidate LMFs of UE1 and the one or more candidate LMFs of UE3 have an intersection. The AMF3 sends a query request 2 to the NRF, which carries the serving AMF of UE1. Optionally, the query request 2 may further carry information such as registration area information and LMF type information of UE2. The NRF returns the query response 2 to the AMF3. The query response 2 includes first information indicating whether the one or more candidate LMFs of UE2 and the one or more candidate LMFs of UE3 have an intersection.

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

[0234] In this step, when AMF3 receives the candidate LMFs of UE1, UE2, and UE3, AMF3 can determine whether one or more candidate LMFs of UE3 have a common portion with one or more candidate LMFs of UE1 or UE2 based on the candidate LMFs of UE1, UE2, and UE3. When AMF3 receives the second information, AMF3 can directly determine whether one or more candidate LMFs of UE3 have a common portion with one or more candidate LMFs of UE1 or UE2 based on the second information.

[0235] Step 805: The LMF 3 selects the UE 1 as the ranging start terminal, and proceeds to step 807.

[0236] In this step, an example is used in which one or more candidate LMFs of UE1 have a common portion with one or more candidate LMFs of UE3. If one or more candidate LMFs of UE2 have a common portion with one or more candidate LMFs of UE3, AMF3 selects UE2 as the ranging source terminal. If the candidate LMFs of both UE1 and UE2 have a common portion with one or more candidate LMFs of UE3, AMF3 may select UE1 or UE2 as the ranging source terminal.

[0237] Step 806: The AMF3 randomly selects one terminal from UE1 and UE2 as the ranging start terminal, and proceeds to step 807.

[0238] In this example, an example is used in which UE1 is selected as the ranging source terminal.

[0239] Step 807: AMF3 selects LMF3 and sends a positioning request to LMF3, where the positioning request may carry the identifiers of UE1 and UE2 and the indication information of the ranging source terminal. Then, step 808 or step 809 is executed.

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

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

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

[0243] Step 809: The AMF3 instructs the ranging source terminal to perform 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 the ranging operation between UE1 and UE2. Therefore, GMLC is used to instruct the ranging source terminal to perform the ranging operation.

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

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

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

[0248] Step 809c: LMF1 starts to perform ranging between UE1 and UE2. The process may involve LMF1, AMF1, UE1 and UE2, and may optionally further involve the RAN.

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

[0250] Step 809e: AMF1 returns the ranging result to LMF3 by using GMLC1.

[0251] Step 810: The LMF3 sends a positioning response to the AMF3, where the positioning response may carry the ranging result.

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

[0253] Step 811b: If ranging is triggered by the UE 3 (see step 801b), the AMF 3 sends the ranging result to the UE 3. For example, the ranging result can be sent to the UE 3 by using a downlink NAS message.

[0254] The above is explained by using three terminals as an example. In a scenario with two terminals, the LMF may also select a ranging initiation terminal based on the principles of the above procedure. In this scenario, the LMF may select the positioning request terminal as the ranging initiation terminal. In a scenario with more than two ranging terminals, the LMF may also select a ranging initiation terminal based on the principles of the above procedure.

[0255] In another possible implementation, AMF3 may first select LMF3 for UE3 and then determine the ranging source terminal. In this case, AMF3 may acquire candidate LMFs for UE1 and UE2 (the method of acquiring candidate LMFs for UE1 and UE2 is the same as the above procedure). If the AMF determines that one or more candidate LMFs for UE1 include LMF3, UE1 may be used as the ranging source terminal. If the AMF determines that one or more candidate LMFs for UE2 include LMF3, UE2 may be used as the ranging source terminal. If the AMF determines that the candidate LMFs for UE1 and UE2 do not include LMF3, UE1 or UE2 may be used as the ranging source terminal. Please refer to the above process for other steps.

[0256] 9 is a diagram of an information exchange procedure in a third example according to an embodiment of the present application. In the third example, the positioning requesting 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 requirements are visible to the AMF, the AMF selects a ranging initiating terminal. As shown in the figure, the procedure may include the following steps:

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

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

[0259] Step 902: AMF3 checks whether UE1's context information or UE2's context information exists; if UE1's context information exists, execute step 903; or if UE1's context information and UE2's context information do not exist, execute step 904.

[0260] For the implementation of this step, please refer to the related descriptions in Figures 8A, 8B and 8C.

[0261] Step 903: AMF 3 selects UE 1 as the ranging start terminal. Then, step 905 is executed.

[0262] In this step, an example is used in which the context information of UE1 exists in AMF3. 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 terminal. If the context information of UE1 and the context information of UE2 exist in AMF3, AMF3 can select UE1 or UE2 as the ranging start terminal.

[0263] Step 904: The AMF3 randomly selects one terminal from UE1 and UE2 as the ranging start terminal, and proceeds to step 908.

[0264] In this example, an example is used in which UE1 is selected as the ranging source terminal.

[0265] Step 905: AMF3 selects LMF3 and sends a positioning request to LMF3, where the positioning request may carry the identifiers of UE1 and UE2 and the indication information of the ranging source terminal. Then, step 906 or step 907 is executed.

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

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

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

[0269] Step 907: The LMF3 sends the ranging result to the AMF3, and then proceeds to step 909a or 909b.

[0270] Step 908: The AMF3 instructs the ranging source terminal to perform ranging 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 the ranging operation between UE1 and UE2. Therefore, GMLC is used to instruct the ranging source terminal to perform the ranging operation.

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

[0273] Step 908a: AMF3 sends a location request to the serving AMF (AMF1) of UE1 by using GMLC3 as the ranging request source.

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

[0275] Step 908c: LMF1 starts to perform ranging between UE1 and UE2. The process may involve LMF1, AMF1, UE1 and UE2, and may optionally further involve the RAN.

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

[0277] Step 908e: AMF1 returns the ranging result to AMF3 by using GMLC1.

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

[0279] Step 909b: If ranging is triggered by the UE 3 (see step 901b), the AMF 3 sends the ranging result to the UE 3. For example, the ranging result can be sent to the UE 3 by using a downlink NAS message.

[0280] The above is explained by using three terminals as an example. In a scenario with two terminals, the LMF may also select a ranging initiation terminal based on the principles of the above procedure. In this scenario, the LMF may select the positioning request terminal as the ranging initiation terminal. In a scenario with more than two ranging terminals, the LMF may also select a ranging initiation terminal based on the principles of the above procedure.

[0281] 10 is a diagram of an information exchange procedure in a fourth example according to an embodiment of the present application. In the fourth example, the positioning requesting 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 requirements are visible to the AMF, the AMF selects a ranging initiating terminal. The AMF also serves as a ranging requester (a network element in the network serves as a requester) and sends a request directly to the AMF of the ranging initiating terminal through the N14 interface. The AMF of the ranging initiating terminal sends a positioning request to the LMF of the ranging initiating terminal. As shown in the figure, the procedure may include the following steps:

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

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

[0284] Step 1002: AMF3 checks whether UE1's context information or UE2's context information exists; if UE1's context information exists, execute step 1003; or if UE1's context information and UE2's context information do not exist, execute step 1004.

[0285] For the implementation of this step, see the related description in Figure 9.

[0286] Step 1003: The AMF 3 selects the UE 1 as the ranging start terminal. Then, step 1005 is executed.

[0287] In this step, an example is used in which the context information of UE1 exists in AMF3. 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 terminal. If the context information of UE1 and the context information of UE2 exist in AMF3, AMF3 can select UE1 or UE2 as the ranging start terminal.

[0288] Step 1004: The AMF 3 randomly selects one terminal from the UE 1 and the UE 2 as the ranging start terminal, and proceeds to step 1006.

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

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

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

[0292] Step 1005a: AMF3 selects LMF3 and sends a positioning request to LMF3, where the positioning request may carry identifiers of UE1 and UE2 and indication information of the ranging source terminal.

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

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

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

[0296] Step 1005c: LMF3 sends the ranging result to AMF3, then proceeds to step 1007a or 1007b.

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

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

[0299] Step 1006a: AMF3 sends a query request to UDM to request to obtain the identifier of the serving AMF of 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 carry an identifier of UE1's serving AMF (i.e., AMF1), and may optionally further carry UE1's registration area information.

[0301] Step 1006c: AMF3 sends a location request to AMF1, where the location request may carry identifiers of UE1 and UE2, and optionally further carry instruction information instructing that UE1 be used as the ranging starting terminal.

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

[0303] Step 1006e: LMF1 starts to perform ranging between UE1 and UE2. The process may involve LMF1, AMF1, UE1 and UE2, and may optionally further involve the RAN.

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

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

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

[0307] Step 1007b: If ranging is triggered by the UE 3 (see step 1001b), the AMF 3 sends the ranging result to the UE 3. For example, the ranging result can be sent to the UE 3 by using a downlink NAS message.

[0308] The above is explained by using three terminals as an example. In a scenario with two terminals, the LMF may also select a ranging initiation terminal based on the principles of the above procedure. In this scenario, the LMF may select the positioning request terminal as the ranging initiation terminal. In a scenario with more than two ranging terminals, the LMF may also select a ranging initiation terminal based on the principles of the above procedure.

[0309] 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 requesting 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 requesting terminal selects a ranging 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 requests an SL ranging service by sending a location request to the AMF 3. The location request may carry identifiers of ranging terminals UE1 and UE2 (UE1 ID and UE2 ID), optionally may further carry an identifier of positioning requesting terminal UE3 (UE3 ID), and may further carry information such as SL ranging service type, measurement type, and SL ranging requirement.

[0312] Optionally, the request triggered by the AF may be sent to the GMLC (ie, GMLC3) of the positioning requesting 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 to request an SL ranging service. The location request may carry identifiers of ranging terminals UE1 and UE2 (UE1 ID and UE2 ID), and may further carry information such as SL ranging service type, measurement type, and SL ranging requirement.

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

[0316] In this step, the AMF3 serves as a ranging requestor and sends ranging requirements to the GMLC3 by using a Location Request message.

[0317] Step 1103a: GMLC3 sends a query request to UDM, where the query request may carry UE1 ID and UE2 ID, requesting the identifiers of the serving AMFs of UE1 and UE2.

[0318] Step 1103b: The UDM returns a query response to the GMLC3, where the query response may include an identifier of the serving AMF of UE1 (UE1 AMF ID) and an identifier of the serving AMF of UE2 (UE2 AMF ID). Optionally, the query response may further include registration area information of UE1 and UE2.

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

[0320] Optionally, GMLC3 may further obtain reachability information of UE1 and reachability information of UE2, UDM context information of UE1 and UDM context information of UE2, and the like from the UDM, and may use the obtained information as a basis for selecting a ranging source terminal.

[0321] Step 1104: The GMLC3 selects a ranging start terminal from UE1 and UE2 based on the information acquired from the UDM.

[0322] Optionally, GMLC3 may select the test initiator 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, an example in which UE1 is selected as the ranging start terminal is used for explanation.

[0324] Step 1105: The GMLC3 sends a location request to the serving AMF (AMF1) of the ranging source terminal UE1, requesting the ranging result between UE1 and UE2.

[0325] Optionally, the location request may carry identifiers of UE1 and UE2, and may optionally further carry indication information indicating that UE1 is used as the ranging source terminal. Furthermore, the location request may carry information such as SL ranging service type, measurement type, and SL ranging requirement.

[0326] Optionally, if AMF1 is not currently in 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 to request the ranging result between UE1 and UE2.

[0328] Optionally, the location request may carry identifiers of UE1 and UE2, and indication information indicating that UE1 is used as the ranging source terminal. Further, the location request may carry information such as SL ranging service type, measurement type, and SL ranging requirement.

[0329] Step 1107: LMF1 starts to perform a ranging operation between UE1 and UE2. The process may involve LMF1, AMF1, UE1 and UE2, and may optionally further involve the RAN.

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

[0331] Step 1109: AMF1 returns the ranging result to LMF3 by using GMLC3.

[0332] Step 1110: If the ranging is triggered by the AF (see step 1101), the GMLC3 sends the ranging result to the AF through the NEF.

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

[0334] Step 1111b: AMF3 sends the ranging result to UE3.

[0335] The above is explained by using three terminals as an example. In a scenario with two terminals, the LMF may also select a ranging initiation terminal based on the principles of the above procedure. In this scenario, the LMF may select the positioning request terminal as the ranging initiation terminal. In a scenario with more than two ranging terminals, the LMF may also select a ranging initiation terminal based on the principles of the above procedure.

[0336] According to the procedures shown in any one of Figures 7A, 7B and 7C to 11, when the AMF and / or LMF of UE1, UE2 and UE3 are different, an appropriate UE is selected from UE1 and UE2 as a ranging initiating UE (initiating UE), and the UE is used as an initiator to start the ranging operation on the PC5 interface, thereby avoiding interaction between multiple AMFs and / or LMFs and reducing complexity.

[0337] Based on the same technical concept, an embodiment of the present application further provides a communication device, which can execute the procedure executed by the LMF 3 in the procedure shown in any one of Figures 5 to 9.

[0338] 12, the communication device 1200 may include a processing unit 1201 and a transceiver unit 1202. The transceiver unit 1202 is coupled to the processing unit 1201.

[0339] The transceiver unit 1202 is configured to receive a first request, where the first request is used to request to perform positioning based on at least one ranging terminal.

[0340] The processing unit 1201 is configured to: determine a ranging initiation terminal, where the ranging initiation terminal is one of at least one ranging terminal, and the ranging initiation terminal satisfies a first requirement; and instruct the ranging initiation terminal to start ranging by using the transceiver unit 1202.

[0341] Optionally, the processing unit 1201 is specifically configured to determine the first terminal as a ranging initiation terminal, where information about the first terminal exists in the first network element, and the first terminal is one of the at least one ranging terminal.

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

[0343] The processing unit 1201 is specifically configured to: determine, by the communication device, a second terminal as a ranging initiation terminal when information about any one of the at least one ranging terminal does not exist in the communication device, where the second terminal is one of the at least one ranging terminal.

[0344] Optionally, the processing unit 1201 is specifically configured to: obtain an identifier of a serving access and mobility management function AMF of at least one ranging terminal from the UDM by using the transceiver unit 1202; obtain one or more candidate LMFs of the at least one ranging terminal from the network repository function NRF by using the transceiver unit 1202 based on the identifier of the serving AMF of the at least one ranging terminal; and, if the one or more candidate LMFs of the second terminal include a communication device, determine that the communication device can be used as an LMF of the second terminal, and determine the second terminal as a ranging initiating terminal.

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

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

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

[0348] Optionally, the second query request carries an identifier of the communication device or first indication information, and the identifier of the communication device or the first indication information indicates that: if there is a ranging terminal that satisfies the first condition among at least one ranging terminal, the communication device can be used as an LMF for the ranging terminal that satisfies the first condition, and the first information is returned. The one or more candidate LMFs for 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 specifically configured to send a third query request to the UMD by using the transceiver unit 1202, where the third query request carries an identifier of the at least one ranging terminal. The transceiver unit 1202 is specifically configured to receive a third query response sent by the UMD, where the third query response carries an identifier of a serving AMF of the at least one ranging terminal.

[0350] When the communication device 1200 executes the procedures performed by the AMF 3 in Figures 5, 6, and 8A, 8B, and 8C to 10, the functions of the above functional modules may include:

[0351] The processing unit 1201 is specifically configured to: determine a third terminal as a ranging initiation terminal when information about any one of the at least one ranging terminal does not exist in the communication device, where the third terminal is one of the at least one ranging terminal.

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

[0353] Optionally, the processing unit 1201 is specifically configured to: obtain an identifier of a 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 by using the transceiver unit 1202 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 a communication device; and determine the third terminal as a ranging initiation terminal 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 part.

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

[0355] Optionally, the processing unit 1201 is specifically configured to: obtain an identifier of a serving AMF of at least one ranging terminal from the UDM by using the transceiver unit 1202; obtain second information from the NRF based on the identifier of the serving AMF of the at least one ranging terminal by using the transceiver 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 determine the third terminal as a ranging initiation terminal based on the second information.

[0356] Optionally, the processing unit 1201 is specifically configured to: obtain an identifier of a serving AMF of at least one ranging terminal from the UDM by using the transceiver unit 1202; obtain second information from the NRF by using the transceiver unit 1202 based on the identifier of each serving AMF of the at least one ranging terminal and the identifier of the serving AMF of the positioning request terminal, 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 portion, and the serving AMF of the positioning request terminal is a communication terminal; and determine the third terminal as a ranging start terminal based on the second information.

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

[0358] Optionally, the fifth query request carries an identifier of the communication device or second indication information, and the identifier of the communication device or the second indication information indicates that the second information is returned if a ranging terminal that satisfies the second condition exists in at least one ranging terminal, where one or more candidate LMFs of the ranging terminal that satisfies the second condition and one or more candidate LMFs of the positioning request terminal have a common portion; or one or more candidate LMFs of the ranging terminal that satisfies the second condition include the LMF of the positioning request terminal, where the ranging terminal that satisfies the second condition includes a third terminal.

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

[0360] Optionally, the processing unit 1201 is specifically configured to send a second request to the second LMF by using the transceiver unit 1202, where the second request carries indication information of the ranging origin terminal.

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

[0362] 13 shows only the necessary structure for the communication device 1300 to execute the method described herein, and does not impose any limitation on the communication device having more components than those described herein. The communication device 1300 may be configured to execute steps performed by an associated network element in the above method embodiments. For example, the associated network element may be a first network element (e.g., a first LMF, a first AMF, a first GMLC, and the like).

[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 communications, for example, to send 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 functionality of the communication device 1300. The memory 1303 and the processor 1302 may be integrated or separate from each other.

[0364] For example, the transceiver 1301 may be a communication port, e.g., a communication port (also referred to as an interface) used for communication between network elements. The transceiver 1301 may also be referred to as a transceiving 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 in a wired manner.

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

[0366] Based on the same concept as the above method embodiment, an embodiment of the present application further provides a computer-readable storage medium, which stores program instructions (also referred to as computer programs or instructions), which, when executed by a processor, enable the computer to perform the operations performed by the first network element in the above method embodiment and any possible implementation of the above method embodiment.

[0367] Based on the same concept as the above method embodiment, the present application further provides a computer program product including program instructions, which, when invoked and executed by a computer, may enable the computer to implement the operations performed by the first network element in the above method embodiment and any possible implementation of the above method embodiment.

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

[0369] Those skilled in the art will recognize that embodiments of the present application may be provided as a method, a system, or a computer program product. Thus, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied in one or more computer-usable storage media (including, but not limited to, disk memory, CD-ROM, optical memory, etc.) containing computer-usable program code.

[0370] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the present application. It should be understood that each procedure and / or block in the flowcharts and / or block diagrams, and / or combinations of procedures and / or blocks in the flowcharts and / or block diagrams, can be implemented using computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or another programmable data processing device to cause a machine, such that the instructions, when executed by the processor of the computer or another programmable data processing device, cause an apparatus to implement the functions specified in one or more procedures in the flowcharts and / or one or more blocks in the block diagrams.

[0371] These computer program instructions may also be stored in a computer-readable memory that instructs a computer or another programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable memory cause an article of manufacture that includes an instruction apparatus that implements the functions specified in one or more steps in the flowcharts and / or one or more blocks in the block diagrams.

[0372] The computer program instructions may alternatively be loaded into a computer or other programmable data processing device such that a sequence of operations and steps are executed on the computer or other programmable device, thereby generating a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing a particular function in one or more procedures of the flowcharts and / or one or more blocks of the block diagrams.

[0373] Of course, those skilled in the art may make various modifications and variations to the present application without departing from the scope of protection of the present application. The present application intends to cover these modifications and variations of the present application as long as they fall within the scope of protection defined by the following claims and their equivalent technologies. 。 [Item 1] receiving a first request by a first network element, wherein the first request is used to request performing positioning based on at least one ranging terminal; determining a ranging source terminal by the first network element, where the ranging source terminal is one of the at least one ranging terminal, and the ranging source terminal satisfies a first requirement; and instructing the ranging source terminal to start ranging by the first network element; A positioning method comprising: [Item 2] The step of determining a ranging source terminal by the first network element, where the ranging source terminal is one of the at least one ranging terminal, and the ranging source terminal satisfies a first requirement, comprises: determining, by the first network element, the first terminal as the ranging origin terminal, where information about the first terminal exists in the first network element, and the first terminal is one of the at least one ranging terminal; Item 1. The method according to item 1, comprising: [Item 3] The first network element is a first location management function (LMF); The step of determining a ranging source terminal by the first network element, where the ranging source terminal is one of the at least one ranging terminal, and the ranging source terminal satisfies a first requirement, comprises: determining, by the first LMF, a second terminal as the ranging origin terminal if information about any one of the at least one ranging terminal does not exist in the first LMF, wherein the second terminal is one of the at least one ranging terminal; Item 1. The method according to item 1, comprising: [Item 4] The step of determining the second terminal as the ranging source terminal by the first LMF includes: obtaining, by the first LMF, an identifier of a serving access and mobility management function AMF of the at least one ranging terminal from a unified data management UDM; obtaining, by the first LMF, one or more candidate LMFs of the at least one ranging terminal from a 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, determining that the first LMF can be used as an LMF of the second terminal and determining the second terminal as the ranging start terminal. The method of item 3, comprising: [Item 5] The step of acquiring, by the first LMF, one or more candidate LMFs of the at least one ranging terminal from an NRF based on the identifier of the serving AMF of the at least one ranging terminal includes: sending, by the first LMF, a first query request to the NRF, where the first query request carries the identifier of the serving AMF of the at least one ranging terminal; and receiving, by the first LMF, a first query response sent by the NRF, wherein the first query response carries one or more identifiers of the one or more candidate LMFs of the at least one ranging terminal; Item 5. The method according to item 4, comprising: [Item 6] The step of determining the second terminal as the ranging start terminal by the first LMF includes: obtaining, by the first LMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM; acquiring, by the first LMF, first information from an NRF based on the identifier of the serving AMF of the at least one ranging terminal, where the first information indicates that the first LMF can be used as an LMF of the second terminal; and determining, by the first LMF, the second terminal as the ranging start terminal based on the first information; Item 3. The method according to item 3, comprising: [Item 7] The step of obtaining, by the first LMF, first information from an NRF based on the identifier of the serving AMF of the at least one ranging terminal includes: sending, by the first LMF, a second query request to the NRF, wherein the second query request carries the identifier of the serving AMF of the at least one ranging terminal; and receiving, by the first LMF, a second query response sent by the NRF, wherein the second query response carries the first information. Item 7. The method according to item 6, comprising: [Item 8] The second query request carries an identifier or first indication information of the first LMF, and the identifier or the first indication information of the first LMF is: If a ranging terminal that satisfies a first condition exists in the at least one ranging terminal, the first LMF can be used as an LMF of the ranging terminal that satisfies the first condition, and the first information is returned, wherein one or more candidate LMFs of 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; Item 7, the method according to item 7, instructing [Item 9] The step of obtaining, by the first LMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM includes: sending, by the first LMF, a third query request to the UDM, wherein the third query request carries an identifier of the at least one ranging terminal; and receiving, by the first LMF, a third query response sent by the UMD, wherein the third query response carries the identifier of the serving AMF of the at least one ranging terminal; 9. The method according to any one of items 4 to 8, comprising: [Item 10] The first network element is a first AMF; The step of determining a ranging source terminal by the first network element, where the ranging source terminal is one of the at least one ranging terminal, and the ranging source terminal satisfies a first requirement, comprises: When information about any one of the at least one ranging terminals does not exist in the first AMF, determining a third terminal as the ranging start terminal by the first AMF, where the third terminal is one of the at least one ranging terminals. Item 1. The method according to item 1, comprising: [Item 11] The step of determining the third terminal as the ranging start terminal by the first AMF includes: obtaining, by the first AMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM; obtaining, by the first AMF, one or more candidate LMFs of the at least one ranging terminal from an NRF based on the identifier of the serving AMF of the at least one ranging terminal; and determining the third terminal as the ranging start terminal when the one or more candidate LMFs of the third terminal include the LMF of the positioning request terminal; including, or; The step of determining the third terminal as the ranging start terminal by the first AMF includes: obtaining, by the first AMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM; and obtaining, by the first AMF, one or more candidate LMFs of the at least one ranging terminal and one or more candidate LMFs of the positioning request terminal from an 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 serving AMF of the positioning request terminal is the first AMF; and determining the third terminal as the ranging start terminal when 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 part; Item 11. The method according to item 10, comprising: [Item 12] The step of obtaining, by the first AMF, one or more candidate LMFs of the at least one ranging terminal from an NRF based on the identifier of the serving AMF of the at least one ranging terminal includes: sending, by the first LMF, a fourth query request to the NRF, wherein the fourth query request carries the identifier of the serving AMF of the at least one ranging terminal; and receiving, by the first LMF, a first query response sent by the NRF, wherein the first query response carries one or more identifiers of the one or more candidate LMFs of the at least one ranging terminal; Item 12. The method according to item 11, comprising: [Item 13] The step of determining the third terminal as the ranging start terminal by the first AMF includes: obtaining, by the first AMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM; Obtaining, by the first AMF, second information from an NRF based on the identifier of the serving AMF of the at least one ranging terminal, where the second information indicates that one or more candidate LMFs of the third terminal include an LMF of a positioning requesting terminal; and determining, by the first AMF, the third terminal as the ranging start terminal based on the second information; or The step of determining the third terminal as the ranging start terminal by the first AMF includes: obtaining, by the first AMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM; Acquiring, by the first AMF, second information from an NRF based on the identifier of the serving AMF of the at least one ranging terminal and an identifier of a serving AMF of a 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 determining, by the first AMF, the third terminal as the ranging start terminal based on the second information; Item 11. The method according to item 10, comprising: [Item 14] The step of acquiring, by the first AMF, second information from an NRF based on the identifier of the serving AMF of the at least one ranging terminal includes: sending, by the first AMF, a fifth query request to the NRF, where the fifth query request carries at least the identifier of the serving AMF of the at least one ranging terminal; and receiving, by the first AMF, a fifth query response sent by the NRF, wherein the fifth query response carries the second information. Item 14. The method according to Item 13, comprising: [Item 15] The fifth query request carries an identifier or second indication information of the first AMF, and the identifier or the second indication information of the first AMF is: If a ranging terminal that satisfies a second condition exists in the at least one ranging terminal, the second information is returned, where one or more candidate LMFs of the ranging terminal that satisfy 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 ranging terminal that satisfy the second condition include the LMF of the positioning request terminal, where the ranging terminal that satisfies the second condition includes the third terminal; Item 15. The method according to item 14, wherein the method instructs [Item 16] The step of obtaining, by the first AMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM includes: sending, by the first AMF, a sixth query request to the UDM, where the sixth query request carries an identifier of the at least one ranging terminal; and receiving, by the first AMF, a sixth query response sent by the UMD, wherein the sixth query response carries the identifier of the serving AMF of the at least one ranging terminal; 16. The method according to any one of items 11 to 15, comprising: [Item 17] the first network element is the first AMF; The step of instructing the ranging source terminal to start ranging by the first network element includes: sending a second request to a second LMF by the first AMF, wherein the second request carries indication information of the ranging start terminal; 16. The method according to any one of items 1, 2, and 10 to 15, comprising: [Item 18] receiving a first position request, wherein the first position request is used to request performing positioning based on at least one ranging terminal; and determining a ranging start terminal, wherein the ranging start terminal is one of the at least one ranging terminal; A positioning method applied to a first gateway mobile location center GMLC, comprising: [Item 19] The step of determining the ranging start terminal includes: determining the ranging origin terminal based on reachability information and / or terminal subscription information of the at least one ranging terminal; Item 19. The method according to item 18, comprising: [Item 20] 20. The method of claim 19, further comprising obtaining the reachability information and / or the terminal subscription information of the at least one ranging terminal from a Unified 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 a UDM comprises: sending a first query request to the UDM, the first query request carrying an identifier of the first ranging terminal, and receiving a first query response sent by the UDM, the first query response carrying reachability information and / or terminal subscription information of the first ranging terminal; and sending a second query request to the UDM, the second query request carrying an identifier of the second ranging terminal, and receiving a second query response sent by the UDM, the second query response carrying reachability information and / or terminal subscription information of the second ranging terminal; Item 21. The method according to Item 20, comprising: [Item 22] sending a query request to the UDM, the query request carrying the identifier of the first ranging terminal, and receiving a query response sent by the UDM, the query response carrying an identifier of a Serving Access and Mobility Management Function (AMF) of the first ranging terminal; and sending a query request to the UDM, the query request carrying the identifier of the second ranging terminal, and receiving a query response sent by the UDM, where the query response carries an identifier of a serving AMF of the second ranging terminal; 22. The method of any one of items 18 to 21, further comprising: [Item 23] The step of receiving a first location request comprises: receiving the first location request from a serving AMF of a positioning requesting terminal, wherein the first location request carries an identifier of the at least one ranging terminal; 23. The method according to any one of items 18 to 22, comprising: [Item 24] sending a second location request to a first AMF, wherein the second location request is used to request obtaining a ranging result between the ranging terminal and another ranging terminal in the at least one ranging terminal; 24. The method of any one of items 18 to 23, further comprising: [Item 25] 25. The method of claim 24, wherein the second location request holds first information, the first information indicates the ranging start terminal, the first AMF is a serving AMF of the ranging start terminal, and the ranging start terminal is one of the at least one ranging terminal. [Item 26] receiving a ranging result transmitted by the serving AMF of the ranging start terminal; and transmitting the ranging result to the serving AMF of the positioning requesting terminal; 26. The method of any one of items 18 to 25, further comprising: [Item 27] 27. The method of any one of items 18 to 26, wherein the first GMLC is a GMLC serving the positioning requesting terminal. [Item 28] A communications device comprising one or more processors, wherein the one or more memories store one or more computer programs, the one or more computer programs including instructions, wherein when the instructions are executed by the one or more processors, the communications device is capable of performing the method according to any one of items 1 to 17 or any one of items 18 to 27. [Item 29] 28. A computer-readable storage medium comprising a computer program, the computer program being capable of causing an electronic device to perform the method of any one of items 1 to 17 or any one of items 18 to 27 when the computer program is run on the electronic device. [Item 30] 28. A computer program product, which, when executed on an electronic device, enables the electronic device to execute the method according to any one of items 1 to 17 or the method according to any one of items 18 to 27. [Item 31] A chip system comprising: a memory configured to store a computer program; and a processor, wherein after the processor calls up the computer program from the memory and executes the computer program, an electronic device in which the chip system is installed executes the method according to any one of items 1 to 17 or any one of items 18 to 27.

Claims

1. receiving a first request by a first network element, wherein the first request is used to request performing positioning based on at least one ranging terminal; determining a ranging source terminal by the first network element, where the ranging source terminal is one of the at least one ranging terminal, and the ranging source terminal satisfies a first requirement; and instructing the ranging source terminal to start ranging by the first network element; A positioning method comprising:

2. The step of determining a ranging source terminal by the first network element, where the ranging source terminal is one of the at least one ranging terminal, and the ranging source terminal satisfies a first requirement, comprises: determining, by the first network element, a first terminal as the ranging initiation terminal, wherein information about the first terminal exists in the first network element, and the first terminal is one of the at least one ranging terminal; The method of claim 1 , comprising:

3. the first network element is a first Location Management Function (LMF); The step of determining a ranging source terminal by the first network element, where the ranging source terminal is one of the at least one ranging terminal, and the ranging source terminal satisfies a first requirement, comprises: determining, by the first LMF, a second terminal as the ranging origin terminal when information about any one of the at least one ranging terminal does not exist in the first LMF, wherein the second terminal is one of the at least one ranging terminal; The method of claim 1 , comprising:

4. The step of determining the second terminal as the ranging start terminal by the first LMF includes: obtaining, by the first LMF, an identifier of a serving access and mobility management function AMF of the at least one ranging terminal from a unified data management (UDM); Obtaining, by the first LMF, one or more candidate LMFs of the at least one ranging terminal from a network repository function (NRF) based on the identifier of the serving AMF of the at least one ranging terminal; and If the one or more candidate LMFs of the second terminal include the first LMF, determining that the first LMF can be used as an LMF of the second terminal and determining the second terminal as the ranging start terminal. The method of claim 3 comprising:

5. The step of obtaining, by the first LMF, one or more candidate LMFs of the at least one ranging terminal from an NRF based on the identifier of the serving AMF of the at least one ranging terminal comprises: sending, by the first LMF, a first query request to the NRF, wherein the first query request carries the identifier of the serving AMF of the at least one ranging terminal; and receiving, by the first LMF, a first query response sent by the NRF, wherein the first query response carries one or more identifiers of the one or more candidate LMFs of the at least one ranging terminal; The method of claim 4, comprising:

6. The step of determining the second terminal as the ranging start terminal by the first LMF includes: obtaining, by the first LMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM; Obtaining, by the first LMF, first information from an NRF based on the identifier of the serving AMF of the at least one ranging terminal, where the first information indicates that the first LMF can be used as an LMF of the second terminal; and determining, by the first LMF, the second terminal as the ranging start terminal based on the first information; The method of claim 3, comprising:

7. The step of obtaining, by the first LMF, first information from an NRF based on the identifier of the serving AMF of the at least one ranging terminal includes: sending, by the first LMF, a second query request to the NRF, wherein the second query request carries the identifier of the serving AMF of the at least one ranging terminal; and receiving, by the first LMF, a second query response sent by the NRF, wherein the second query response carries the first information. The method of claim 6, comprising:

8. The second query request carries an identifier of the first LMF or first indication information, and the identifier of the first LMF or the first indication information is: If a ranging terminal that satisfies a first condition exists in the at least one ranging terminal, the first LMF can be used as an LMF of the ranging terminal that satisfies the first condition, and the first information is returned, wherein one or more candidate LMFs of 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. The method of claim 7, wherein the

9. The step of obtaining an identifier of a serving AMF of the at least one ranging terminal from a UDM by the first LMF includes: sending, by the first LMF, a third query request to the UDM, wherein the third query request carries an identifier of the at least one ranging terminal; and receiving, by the first LMF, a third query response sent by the UMD, wherein the third query response carries the identifier of the serving AMF of the at least one ranging terminal; 9. The method of claim 4, comprising:

10. The first network element is a first AMF; The step of determining a ranging source terminal by the first network element, where the ranging source terminal is one of the at least one ranging terminal, and the ranging source terminal satisfies a first requirement, comprises: If information about any one of the at least one ranging terminals does not exist in the first AMF, determining a third terminal as the ranging initiation terminal by the first AMF, wherein the third terminal is one of the at least one ranging terminals. The method of claim 1 , comprising:

11. The step of determining the third terminal as the ranging start terminal by the first AMF includes: obtaining, by the first AMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM; Obtaining, by the first AMF, one or more candidate LMFs of the at least one ranging terminal from an NRF based on the identifier of the serving AMF of the at least one ranging terminal; and determining the third terminal as the ranging start terminal when the one or more candidate LMFs of the third terminal include the LMF of the positioning request terminal; or The step of determining the third terminal as the ranging start terminal by the first AMF includes: obtaining, by the first AMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM; Obtaining, by the first AMF, one or more candidate LMFs of the at least one ranging terminal and one or more candidate LMFs of the positioning request terminal from an 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 serving AMF of the positioning request terminal is the first AMF; and determining the third terminal as the ranging start terminal when 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 method of claim 10, comprising:

12. The step of obtaining, by the first AMF, one or more candidate LMFs of the at least one ranging terminal from an NRF based on the identifier of the serving AMF of the at least one ranging terminal comprises: sending, by the first LMF, a fourth query request to the NRF, wherein the fourth query request carries the identifier of the serving AMF of the at least one ranging terminal; and receiving, by the first LMF, a first query response sent by the NRF, wherein the first query response carries one or more identifiers of the one or more candidate LMFs of the at least one ranging terminal; The method of claim 11 , comprising:

13. The step of determining the third terminal as the ranging start terminal by the first AMF includes: obtaining, by the first AMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM; Obtaining, by the first AMF, second information from an NRF based on the identifier of the serving AMF of the at least one ranging terminal, where the second information indicates that one or more candidate LMFs of the third terminal include an LMF of a positioning requesting terminal; and determining, by the first AMF, the third terminal as the ranging start terminal based on the second information; or The step of determining the third terminal as the ranging start terminal by the first AMF includes: obtaining, by the first AMF, an identifier of a serving AMF of the at least one ranging terminal from a UDM; Obtaining, by the first AMF, second information from an NRF based on the identifier of the serving AMF of the at least one ranging terminal and an identifier of a serving AMF of a positioning requesting 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 requesting terminal have a common part, and the serving AMF of the positioning requesting terminal is the first AMF; and determining, by the first AMF, the third terminal as the ranging start terminal based on the second information; The method of claim 10, comprising:

14. The step of obtaining, by the first AMF, second information from an NRF based on the identifier of the serving AMF of the at least one ranging terminal includes: sending, by the first AMF, a fifth query request to the NRF, where the fifth query request carries at least the identifier of the serving AMF of the at least one ranging terminal; and receiving, by the first AMF, a fifth query response sent by the NRF, wherein the fifth query response carries the second information.

14. The method of claim 13, comprising:

15. The fifth query request carries an identifier of the first AMF or second indication information, and the identifier of the first AMF or the second indication information is: If a ranging terminal that satisfies a second condition exists in the at least one ranging terminal, the second information is returned, where one or more candidate LMFs of the ranging 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 ranging terminal that satisfies the second condition include the LMF of the positioning request terminal, where the ranging terminal that satisfies the second condition includes the third terminal. The method of claim 14, wherein the

16. The step of obtaining an identifier of a serving AMF of the at least one ranging terminal from a UDM by the first AMF comprises: sending, by the first AMF, a sixth query request to the UDM, wherein the sixth query request carries an identifier of the at least one ranging terminal; and receiving, by the first AMF, a sixth query response sent by the UMD, wherein the sixth query response carries the identifier of the serving AMF of the at least one ranging terminal; 16. The method of any one of claims 11 to 15, comprising:

17. the first network element is the first AMF; The step of instructing the ranging source terminal to start ranging by the first network element includes: sending a second request to a second LMF by the first AMF, wherein the second request carries indication information of the ranging start terminal; 16. The method of any one of claims 1, 2, and 10 to 15, comprising:

18. receiving a first position request, wherein the first position request is used to request performing positioning based on at least one ranging terminal; and determining a ranging start terminal, wherein the ranging start terminal is one of the at least one ranging terminal; A positioning method applied to a first gateway mobile location center GMLC, comprising:

19. The step of determining the ranging start terminal includes: determining the ranging origin terminal based on reachability information and / or terminal subscription information of the at least one ranging terminal; 20. The method of claim 18, comprising:

20. 20. The method of claim 19, further comprising obtaining the reachability information and / or the terminal subscription information of the at least one ranging terminal from a Unified Data Management (UDM).

21. The step of obtaining the reachability information and / or terminal subscription information of the at least one ranging terminal from a UDM comprises: sending a first query request to the UDM, the first query request carrying an identifier of the first ranging terminal, and receiving a first query response sent by the UDM, the first query response carrying reachability information and / or terminal subscription information of the first ranging terminal; and sending a second query request to the UDM, the second query request carrying an identifier of the second ranging terminal, and receiving a second query response sent by the UDM, the second query response carrying reachability information and / or terminal subscription information of the second ranging terminal; 21. The method of claim 20, comprising:

22. sending a query request to the UDM, the query request carrying the identifier of the first ranging terminal, and receiving a query response sent by the UDM, the query response carrying an identifier of a Serving Access and Mobility Management Function (AMF) of the first ranging terminal; and Sending a query request to the UDM, the query request carrying the identifier of the second ranging terminal, and receiving a query response sent by the UDM, where the query response carries an identifier of a serving AMF of the second ranging terminal.

22. The method of any one of claims 18 to 21, further comprising:

23. The step of receiving a first location request comprises: receiving the first location request from a serving AMF of a positioning requesting terminal, wherein the first location request carries an identifier of the at least one ranging terminal; 23. The method of any one of claims 18 to 22, comprising:

24. Sending a second location request to a first AMF, wherein the second location request is used to request obtaining a ranging result between the ranging terminal and another ranging terminal in the at least one ranging terminal; 24. The method of any one of claims 18 to 23, further comprising:

25. 25. The method of claim 24, wherein the second location request carries first information, the first information indicating the ranging source terminal, the first AMF being a serving AMF of the ranging source terminal, and the ranging source terminal being one of the at least one ranging terminal.

26. Receiving a ranging result transmitted by the serving AMF of the ranging initiation terminal; and transmitting the ranging result to the serving AMF of the positioning requesting terminal.

26. The method of any one of claims 18 to 25, further comprising:

27. 27. The method of claim 18, wherein the first GMLC is a GMLC serving the positioning requesting terminal.

28. 28. A communications device comprising one or more processors, wherein the one or more memories store one or more computer programs, the one or more computer programs comprising instructions, wherein when the instructions are executed by the one or more processors, the communications device is capable of performing the method of any one of claims 1 to 17 or any one of claims 18 to 27.

29. 28. A computer-readable storage medium comprising a computer program, which when running on an electronic device enables the electronic device to perform the method of any one of claims 1 to 17 or the method of any one of claims 18 to 27.

30. 28. A computer program product, which when running on an electronic device enables the electronic device to perform the method of any one of claims 1 to 17 or the method of any one of claims 18 to 27.

31. A chip system comprising: a memory configured to store a computer program; and a processor, wherein after the processor calls the computer program from the memory and executes the computer program, an electronic device in which the chip system is installed executes the method of any one of claims 1 to 17 or the method of any one of claims 18 to 27.

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