UE ID mapping for 5G sidelink ranging and positioning

Abstract

The present disclosure relates to systems and methods for mapping user equipment (UE) identities (IDs), such as for sidelink ranging / positioning. In one embodiment, a method performed by a network node includes receiving a service request from a network function (NF) consumer, the service request including either (a) a subscription persistent identifier (SUPI) of a particular UE or (b) a sidelink ranging application user identification (SRAUID) and / or a sidelink ranging discovery user identification (SRDUID) of the particular UE. The method further includes sending a response to the NF consumer, the response including either (a) an SRAUID mapped to the SUPI of the particular UE and / or an SRDUID mapped to the SUPI of the particular UE if the service request includes the SUPI of the particular UE, or (b) an SRAUID mapped to the SRAUID of the particular UE and / or an SRDUID of the particular UE if the service request includes the SRAUID and / or the SRDUID of the particular UE.

Description

Related Applications

[0001] This application claims the benefit of international patent application serial number PCT / CN2022 / 110838 filed on August 8, 2022, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates to sidelink ranging and positioning in cellular communication systems. Background Art

[0003] Regarding the terminology of sidelink ranging and positioning, the 3rd Generation Partnership Project (3GPP) Technical Report (TR) 23.700-86 (see, for example, version V0.3.0) defines various terms, as shown in the following excerpt from 3GPP TR 23.700-86: *****TR 23.700-86 excerpt begins***** Ranging: refers to determining the distance between two or more UEs through the PC5 interface, and / or the direction and / or relative positioning of one UE (i.e., target UE) relative to another UE (i.e., reference UE). Reference UE: A UE that determines the reference plane and reference direction in ranging-based service and sidelink positioning. NOTE 1: The reference UE is the same as the observer UE used in TR 22.855 [2]. Target UE: In ranging-based service and sidelink positioning, a UE whose distance, direction and / or position is measured compared to a reference plane, reference direction and / or position of a reference UE. NOTE 2: Any UE participating in ranging / sidelink positioning can be both a target UE and a reference UE, and can switch roles in the same ranging / sidelink positioning session. Editor's Note: Regarding reference UE and target UE, whether new names will be defined to distinguish them from the terms reference UE and target UE used in eLCS is for further study (FFS). Assisted UE: A UE that provides ranging / sidelink positioning assistance when ranging / sidelink positioning cannot be performed directly between the reference UE and the target UE. Positioned UE: A UE whose location is known or can be known using Uu-based positioning. A positioned UE can be used to determine the location of a target UE using sidelink positioning. Editor's Note: Changed the terminology "network-assisted UE" and "second UE" to "positioning UE" throughout the document. Location server UE: Provides location server functionality to replace LMF for UEs that perform sidelink positioning and ranging via sidelink. The location server UE interacts with the target UE, reference UE, auxiliary UE, and positioning UE as needed to calculate the location of the target UE. Sidelink positioning: Use PC5 to locate the UE. Positioning: The function of detecting the geographical location and (optionally) the speed (eg, the speed of a mobile terminal). Relative position: An estimate of the UE's position relative to other network elements or other UEs. Editor’s Note: Definitions of ranging and sidelink positioning terms will be aligned with the RAN Working Group and will be revisited when any conclusions are reached by the RAN Working Group. *****End of excerpt from TR 23.700-86*****

[0004] There is a key issue #3 in 3GPP TR 23.700-86 regarding ranging / sidelink positioning device discovery, as shown in the following excerpt from 3GPP TR 23.700-86: *****TR 23.700-86 excerpt begins***** In most cases, two or more UEs in ranging-based services and sidelink positioning cannot always be aware of each other even if they are very close. In order for the reference observer UE and the target UE to perform measurements and communicate to transfer measurement data, the UEs need to be discovered by each other first. The discovery procedure is used to enable the UE to discover other nearby UEs or be discovered by other nearby UEs through the PC5 interface, in order to perform ranging and sidelink positioning. In terms of who provides the reference plane and reference direction, the reference UE and the target UE are two roles in the ranging-based service and sidelink positioning. Either of them can be discovered by the other. Ranging / sidelink positioning device discovery can be triggered at the UE itself and / or based on network instructions (e.g., when, within which distance / angle, or which UEs can be discovered under network monitoring). Under this key issue, the following aspects need to be addressed: 1. How the reference UE and target UE are identified by each other for UE-triggered and network-triggered ranging / sidelink positioning in coverage, partial coverage and out of coverage Discovery to perform ranging-based services and sidelink positioning, taking into account the following factors: -How can a target UE and a reference UE be discovered by each other? -How can a target UE and multiple reference UEs be discovered by each other? -How can a reference UE and multiple target UEs be discovered by each other? NOTE 1: The ProSe direct discovery process should be reused whenever possible. 2. How to trigger the discovery of ranging / sidelink positioning devices at the UE based on network instructions in the cases of in-coverage, partial coverage and out-of-coverage? NOTE 2: It is assumed that both the reference UE and the target UE have ranging / sidelink positioning capabilities. *****End of excerpt from TR 23.700-86*****

[0005] Some solutions to key issue #3 described in 3GPP TR 23.700-86 are described in the following excerpt from 3GPP TR 23.700-86: *****First excerpt from TR23.700-86 begins***** 6.7 Solution #7: Network-based UE-side link positioning 6.7.1 Introduction This solution addresses key issue #5 and proposes a solution where the network performs UE positioning estimation based on network-assisted sidelink positioning. 6.7.2 Functional Description This solution addresses key issue #5 for the MT-LR case and uses the following principles: - A UE within the network coverage, whether directly via Uu or via L2 U2N relay, is in a position where it cannot be positioned based on Uu - The MT-LR procedure is triggered by the network as specified in clause 6.1 of TS 23.273

[11] . -LMF requests UE to perform positioning measurements -The UE checks whether the UE can perform positioning measurements on other RAN nodes or whether a sidelink positioning method needs to be used. The UE determines that Uu-based positioning is not possible and sidelink positioning needs to be performed. The UE searches for another UE that can estimate its own position based on Uu measurements and supports ranging services. Note 1: The discovery of the second UE depends on the solution of key issue #3 “Ranging / Sidelink Positioning Device Discovery” - The UE performs ranging estimation measurements on the second UE and provides ranging estimation or ranging measurement data to the LMF. The UE also includes the UE ID of the second UE. NOTE 2: LPP (TS 37.355

[10] ) may need to be enhanced to support new measurement messages to support sidelink positioning. - When the network receives the information from the UE, the network may use the known position of the second UE, or trigger a new position estimate from the second UE. The LMF triggers any positioning procedure specified in clause 6.11 of TS 23.273

[11] to estimate the position of the second UE. -Based on the position estimate of the second UE, the LMF can estimate the position of the UE, which is the UE to which the first positioning request was sent. NOTE 3: RAN studies on sidelink positioning will determine the accuracy of the sidelink position, e.g. whether multilateration estimation is required. 6.7.3 Process 6.7.3.1 Network-based UE-side link positioning estimation (MT-LR). [Copy here as Figure 1 ] Figure 6 .7.3.1-1: Network-based UE-side link location estimation (MT-LR) 0. The AMF is triggered to start the location reporting procedure for UE1 as specified in TS 23.273

[11] . UE1 may be within the network coverage and communicating via Uu, or UE1 may communicate with the network using a Layer 2 UE-to-network relay. The Layer 2 UE-to-network relay may be a second UE or a different UE capable of providing Layer 2 UE-to-network services. NOTE 1: UE1 and UE2 may be registered and served by different AMFs. 1. According to TS23.273

[11] , AMF sends an initial request to LMF 2. In accordance with clause 6.11.1 of TS23.273

[11] , LMF uses Namf_Communication_N1N2messageTransfer to send a downlink positioning message to UE1. 3.UE1 decides to perform a discovery procedure to find a UE that supports sidelink positioning and Uu-based measurements (e.g., because UE1 has determined that it cannot perform traditional Uu positioning measurements). UE1 selects UE2. NOTE 2: The logic for determining which UE to use sidelink positioning is based on the UE implementation. For example, the UE may determine that Uu positioning is not possible based on the limited number of cells that UE1 can detect. NOTE 3: It is assumed that a discovery solution that solves key issue #3 can be used. During the discovery procedure, UE1 will obtain the UE_ID of UE2, which supports the positioning procedure defined in TS 23.273

[11] . UE_ID is the ID used by UE2 during the ProSe discovery procedure. 4. UE1 performs ranging / sidelink relative distance measurement on UE2. Note 4: It is assumed that a solution to key issue #4 is available. 5. UE1 sends a UL positioning message to LMF. The message contains ranging / sidelink positioning data and UE2's UE_ID. 6.LMF resolves the received UE_ID of UE2 by querying DDNMF and triggers the location determination of UE2. LMF may need to query UDM to find the AMF serving UE2 to start the positioning process. NOTE 4: It is assumed that LMF uses the service-based interface N5g-ddnmf to interact with DDNMF. 7. The LMF triggers the serving AMF to start the positioning procedure. The LMF receives the LCS association ID and cell ID of UE2 from the AMF and performs one or more positioning procedures described in clauses 6.11.1, 6.11.2 and 6.11.3 of TS23.273

[11] to determine the location of UE2. The LMF determines the location of UE1 based on the sidelink positioning data received in step 5 and the location of UE2. NOTE 5: UE1 mobility may impact the LMF position estimate of UE2. To reduce the impact, the LMF can try to time synchronize the UE1 position measurements and the sidelink measurements, or use timestamps and estimate the mobility based on the movement trajectory. This is a common theme for all solutions that use non-stationary devices to participate in another UE's position estimate. 8.LMF provides the UE1 location to AMF as a response to the request in step 1. ***** Second excerpt from TR 23.700-86 begins***** 6.21 Solution #21: Network-assisted sidelink positioning for partial coverage 6.21.1 Overview This solution is to address key issue #5. The UE out of coverage may be a UE that is not registered with the network or a UE that is temporarily unreachable. The UE out of coverage may be located in a known area, such as a factory or campus, or may not be in a known area, and the application server may want to know its exact location. When the UE is out of coverage, it cannot be directly positioned through Uu, and communication between the UE and 5GC is also impossible. When 5GC determines that the UE is out of network coverage, it can consider using network-assisted side link positioning to estimate the UE location. Since network-assisted sidelink positioning requires ranging / sidelink positioning between the UE and the network-assisted UE, the network-assisted UE needs to be identified. The network-assisted UE needs to be in the vicinity of the out-of-coverage UE; however, it should not be assumed that the UE will actively discover the network-assisted UE because it does not know when a location service request will be received. 6.21.2 Functional description The UE's location service request can be sent by the application server (through NEF) or LCS client to the GMLC, and then the GMLC forwards the service request to the AMF. When the UE is out of coverage, the serving AMF needs to be determined by the GMLC. The GMLC or AMF can determine the UE is out of coverage, and then the GMLC or AMF will trigger network-assisted sidelink positioning to locate the UE based on the serving AMF address retrieval result or paging result: Case 1: When the GMLC retrieves the AMF address from the UDM using the SUPI of this UE and the network address of the current serving AMF is not returned Case 2: When the UE's serving AMF identifies that the UE is in CM-IDLE state and paging cannot be successful For case 1, if the application server knows the target area where the UE is located, the application server will provide the target area to the GMLC in the LCS service request, and then the GMLC will map the target area to the cell ID / gNB ID / TAI and derive the AMF that can provide service for this area. For case 2, the serving AMF is determined based on the successful retrieval of the AMF address from the UDM. The serving AMF of the UE / target area is responsible for discovering / selecting the network-assisted UE, which can be achieved in 2 steps: 1. Providing network-assisted UE candidates: The AMF may pre-configure a list of network-assisted UEs, assuming these network-assisted UEs are mobile, or if the UE provides its capability to be a network-assisted UE during registration, the AMF stores it into the UE context. The AMF selects network-assisted UE candidates from the pre-configured list or based on the UE capabilities. 2. Select serving network-assisted UE from the network-assisted UE candidate list: If a target area is provided, the AMF selects one or more network-assisted UEs based on the target area identified by cell ID / gNB ID / TAI. If the last known cell ID of the target UE is provided, the AMF selects one or more network-assisted UEs based on the cell ID. The AMF then selects an LMF that supports network-assisted sidelink positioning as the serving LMF for the selected network-assisted UE, and sends an LCS service request to the LMF, providing the UE ID and one or more network-assisted UE IDs. When receiving both the UE ID and one or more network-assisted UE IDs, the LMF performs network-assisted sidelink positioning, including: - One or more network-assisted UEs discover the UE via PC5. When one or more network-assisted UEs have reported successful discovery of the UE, the LMF may decide to stop discovery. -Measure and derive UE position from: - Ranging / sidelink positioning results / measurement data between the UE and one or more network-assisted UEs. - Uu positioning results / measurement data of one or more network-assisted UEs. 6.21.3 Process [Copy here as Figure 2 ] 6.21.3.2-1: Network-assisted sidelink positioning procedure for partial coverage 0. The network-assisted UE provides its network-assisted sidelink positioning capability in the registration request to the AMF, and the AMF stores it in the UE context. 1.GMLC receives LCS service request from AF / LCS client, which may contain the target area where the UE is located. GMLC uses UDM to check service authorization and privacy. 2.GMLC retrieves the serving AMF for the target UE from the UDM. If no AMF address is returned and the target area is provided in the LCS service request, the GMLC decides to locate the target UE using network-assisted sidelink positioning. The GMLC maps the target area to the cell ID / gNB ID / TAI, from which it derives the serving AMF that can serve the area as the serving AMF for the network-assisted UE. If an AMF address is returned, the GMLC selects that AMF as the serving AMF for the target UE. 3.GMLC sends an LCS Service Request to the selected AMF, which contains the cell ID / gNB ID / TAI of the target area (if available). NOTE: When the AMF is derived based on the cell ID / gNB ID / TAI that identifies the target area, and multiple AMFs are derived, the LCS service request may be sent to some or all AMFs. 4. If the UE is in CM IDLE state, the AMF initiates the network-triggered service request procedure (as defined in clause 4.2.3.3 of TS23.502 [9]) to establish a signaling connection with the UE. When the AMF is derived based on the cell ID / gNB ID / TAI identifying the target area, and there is no available UE state, this step is skipped. 5. If the UE cannot be successfully paged in step 4, the AMF decides to invoke network-assisted sidelink positioning to locate the UE. The AMF selects one or more network-assisted UEs based on UE capabilities, cell ID / gNB ID / TAI of the target area, the last known cell ID of the target UE, and pre-configured information. 6.AMF selects an LMF that is capable of network-assisted side-link positioning. 7.AMF sends an LCS service request to LMF, which contains the target UE ID and one or more network assisted UEIDs. Editor’s note: Security issues such as whether the selected list of network-assisted UEs allows for possession of ranging / sidelink positioning information of the target UE are for further study (FFS) and will be evaluated in SA WG3. 8. When the UE ID and one or more network-assisted UE IDs are received in the LCS service request at the same time, the LMF sends a ranging / side link positioning request to one or more network-assisted UEs to trigger the ranging / side link positioning process. 9. The network assists the UE to trigger the ranging / sidelink positioning process, which includes the discovery and service operation process through PC5. 10. The network-assisted UE reports ranging / sidelink positioning measurements or results to the LMF. The LMF may receive measurement or result reports from multiple network-assisted UEs, and the LMF may determine whether to stop further reporting from other network-assisted UEs based on QoS requirements or pre-configuration. 11. The LMF triggers one or more procedures for locating one or more network-assisted UEs. The LCS position estimate for the UE is generated based on the ranging / sidelink positioning results / measurement data between the UE and one or more network-assisted UEs and the Uu positioning results / measurement data of one or more network-assisted UEs. 12.LMF provides the UE’s LCS position estimate to the GMLC. 13.GMLC provides the UE’s LCS position estimate to the AF or LCS client. *****End of excerpt from TR 23.700-86***** Summary of the invention

[0006] The present disclosure relates to systems and methods for mapping user equipment (UE) identification (ID), such as for sidelink ranging and positioning. In one embodiment, a method performed by a network node includes receiving a service request from a network function (NF) consumer, the service request including any of the following: (a) a subscription permanent identifier (SUPI) of a specific UE or (b) a sidelink ranging application user identity (SRAUID) of a specific UE and / or a sidelink ranging discovery user identity (SRDUID) of a specific UE. The method also includes sending a response to the NF consumer, the response including any of the following: (a) if the service request includes the SUPI of the specific UE, the SRAUID mapped to the SUPI of the specific UE and / or the SRDUID mapped to the SUPI of the specific UE, or (b) if the service request includes the SRAUID of the specific UE and / or the SRDUID and / or the SRDUID of the specific UE, the SUPI mapped to the SRAUID and / or the SRDUID of the specific UE. In this way, whether using SUPI or SRAUID / SRDUID, the UE can be identified by the network node and / or other network nodes.

[0007] In one embodiment, the service request includes the SUPI of the specific UE and additional information including either or both of the application ID and the sidelink positioning service code, and the response includes the SRAUID and / or SRDUID mapped to the SUPI.

[0008] In one embodiment, the network node stores a mapping between the SUPI of a specific UE and the SRAUID and / or SRDUID of the specific UE.

[0009] In one embodiment, the home public land mobile network (HPLMN) of the specific UE is different from the public land mobile network (PLMN) where the network node is located, and the service request includes the SUPI of the specific UE. In addition, the method also includes sending the service request to a second network node in the HPLMN of the UE and receiving a response from the second network node, the response from the second network node including an SRAUID mapped to the SUPI of the specific UE and / or an SRDUID mapped to the SUPI of the specific UE.

[0010] In one embodiment, the HPLMN of the specific UE is different from the PLMN in which the network node is located, and the service request includes the SRAUID and / or SRDUID of the specific UE. In addition, the method also includes sending the service request to a second network node in the HPLMN of the UE and receiving a response from the second network node, the response from the second network node including a SUPI mapped to the SRAUID and / or SRDUID of the specific UE.

[0011] In one embodiment, the method further includes, before receiving the service request, receiving a registration request from a specific UE, the registration request including the SUPI of the specific UE and additional information, the additional information including information indicating the service associated with the registration request and an application ID, and determining whether the specific UE is authorized to use the service. The method further includes, in response to determining that the specific UE is authorized to use the service, storing a mapping between the SUPI of the specific UE and the SRAUID and / or SRDUID of the specific UE, the SRAUID and / or SRDUID of the specific UE being included in the registration request or generated by a network node. In one embodiment, the SRAUID and / or SRDUID of the specific UE are included in the registration request. In another embodiment, the method further includes generating the SRAUID and / or SRDUID of the specific UE. In one embodiment, the method further includes sending a registration response to the specific UE, the registration response including the SRAUID and / or SRDUID of the specific UE.

[0012] In one embodiment, the NF consumer is a Location Management Function (LMF).

[0013] In one embodiment, the service request is associated with a sidelink ranging or positioning procedure, and the specific UE is a UE for which sidelink positioning is enabled for the sidelink ranging or positioning procedure.

[0014] In one embodiment, the network node is a network node implementing a Direct Discovery Name Management Function (DDNMF).

[0015] An embodiment of a corresponding network node is also disclosed. In one embodiment, the network node is adapted to receive a service request from an NF consumer, the service request including any of the following: (a) a SUPI of a specific UE or (b) a SRAUID of a specific UE and / or a SRDUID of a specific UE. The network node is also adapted to send a response to the NF consumer, the response including any of the following: (a) if the service request includes a SUPI of a specific UE, a SRAUID mapped to the SUPI of the specific UE and / or a SRDUID mapped to the SUPI of the specific UE, or (b) if the service request includes a SRAUID of a specific UE and / or a SRDUID and / or a SRDUID of a specific UE, a SUPI mapped to the SRAUID and / or SRDUID of the specific UE.

[0016] In one embodiment, the network node includes a processing circuit configured to cause the network node to receive a service request from a NF consumer, the service request including any of the following: (a) a SUPI of a specific UE or (b) a SRAUID of a specific UE and / or a SRDUID of a specific UE. The processing circuit is also configured to cause the network node to send a response to the NF consumer, the response including any of the following: (a) if the service request includes the SUPI of the specific UE, the SRAUID mapped to the SUPI of the specific UE and / or the SRDUID mapped to the SUPI of the specific UE, or (b) if the service request includes the SRAUID of the specific UE and / or the SRDUID and / or the SRDUID of the specific UE, the SUPI mapped to the SRAUID and / or the SRDUID of the specific UE.

[0017] Embodiments of methods performed by a UE are also disclosed. In one embodiment, the method performed by a UE includes sending a registration request to a network node, the registration request including the SUPI of the UE and a SRAUID of a specific UE and / or a SRDUID of a specific UE.

[0018] The present invention also discloses a corresponding embodiment of the UE. In one embodiment, the UE is adapted to send a registration request to a network node, the registration request including the SUPI of the UE and the SRAUID of a specific UE and / or the SRDUID of a specific UE.

[0019] In one embodiment, the UE includes one or more transmitters, one or more receivers, and a processing circuit associated with the one or more transmitters and the one or more receivers. The processing circuit is configured to cause the UE to send a registration request to the network node, the registration request including the SUPI of the UE and the SRAUID of a specific UE and / or the SRDUID of a specific UE.

[0020] In one embodiment, the method performed by the UE includes sending a registration request to a network node, the registration request including the SUPI of the UE, and receiving a registration response from the network node, the registration response including the SRAUID assigned to the UE and / or the SRDUID assigned to the UE.

[0021] The present invention also discloses a corresponding embodiment of the UE. In one embodiment, the UE is adapted to send a registration request to a network node, the registration request including the SUPI of the UE, and receive a registration response from the network node, the registration response including the SRAUID allocated to the UE and / or the SRDUID allocated to the UE.

[0022] In one embodiment, the UE includes one or more transmitters, one or more receivers, and processing circuits associated with the one or more transmitters and the one or more receivers. The processing circuits are configured to cause the UE to send a registration request to a network node, the registration request including the SUPI of the UE, and receive a registration response from the network node, the registration response including the SRAUID assigned to the UE and / or the SRDUID assigned to the UE. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several aspects of the disclosure and together with the description serve to explain the principles of the disclosure.

[0024] Figure 1 It is a third generation partnership project (3GPP) technical report (TR) 23.700-86. Figure 6 .7.3.1-1 duplication;

[0025] Figure 2 It is in 3GPP TR 23.700-86 Figure 6 .21.3.2-1 duplication;

[0026] Figure 3 An example of a cellular communication system according to some embodiments of the present disclosure is shown;

[0027] Figure 4 Shows Figure 3 The cellular communication system in is an example embodiment of a fifth generation (5G) system (5GS), and more specifically, shows a reference architecture for sidelink positioning and ranging based services for non-roaming and same public land mobile network (PLMN) operations currently defined in 3GPP TR23.700-86;

[0028] Figure 5 , Figure 6 , Figure 7 , Figure 8, Fig. 9 and Fig.10 An example embodiment of the present disclosure is shown;

[0029] Fig.11 is a schematic block diagram of a network node according to some embodiments of the present disclosure;

[0030] Fig.12 According to some embodiments of the present disclosure Fig.11 A schematic block diagram of an embodiment of a virtualization of a network node in;

[0031] Fig.13 According to some other embodiments of the present disclosure Fig.11 A schematic block diagram of a network node in;

[0032] Fig.14 is a schematic block diagram of a user equipment (UE) according to some embodiments of the present disclosure; and

[0033] Fig.15 According to some other embodiments of the present disclosure Fig.14 A schematic block diagram of a UE in FIG. DETAILED DESCRIPTION

[0034] The embodiments set forth below provide information that enables those skilled in the art to practice these embodiments and illustrate the best way to practice these embodiments. By reading the following description in conjunction with the accompanying drawings, those skilled in the art will understand the concepts of the present disclosure and will recognize the applications of these concepts not specifically addressed herein. It should be understood that these concepts and applications are within the scope of the present disclosure.

[0035] Radio Node: As used herein, a "radio node" is a radio access node or a wireless communication device.

[0036] Radio access node: As used herein, a "radio access node" or "radio network node" or "radio access network node" is any node in a radio access network (RAN) of a cellular communication network for wireless transmission and / or reception of signals. Some examples of radio access nodes include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a 3rd Generation Partnership Project (3GPP) fifth generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high power or macro base station, a low power base station (e.g., a micro base station, a pico base station, a home eNB, etc.), a relay node, a network node implementing part of the functionality of a base station, or a network node implementing a gNB distributed unit (gNB-DU)), or a network node implementing part of the functionality of some other type of radio access node.

[0037] Core network node: As used herein, a "core network node" is any type of node in a core network, or any node that implements a core network function. Some examples of core network nodes include, for example, Mobility Management Entity (MME), Packet Data Network Gateway (P-GW), Service Capability Exposure Function (SCEF), Home Subscriber Server (HSS), etc. Some other examples of core network nodes include nodes that implement Access and Mobility Function (AMF), User Plane Function (UPF), Session Management Function (SMF), Authentication Server Function (AUSF), Network Slice Selection Function (NSSF), Network Exposure Function (NEF), Network Function (NF) Repository Function (NRF), Policy Control Function (PCF), Unified Data Management (UDM), etc.

[0038] Communication Device: As used herein, a "communication device" is any type of device that is capable of accessing an access network. Some examples of communication devices include, but are not limited to, mobile phones, smartphones, sensor devices, meters, vehicles, household appliances, medical devices, media players, cameras, or any type of consumer electronics, such as, but not limited to, televisions, radios, lighting devices, tablets, laptops, or personal computers (PCs). A communication device may be a portable, handheld, computer-enclosed, or vehicle-mounted mobile device capable of voice and / or data communications via wireless or wired connections.

[0039] Wireless communication device: One type of communication device is a wireless communication device, which can be any type of wireless device that can access (i.e., be served by) a wireless network (e.g., a cellular network). Some examples of wireless communication devices include, but are not limited to: User Equipment (UE) in 3GPP networks, Machine Type Communication (MTC) devices, and Internet of Things (IoT) devices. These wireless communication devices can be or can be integrated into mobile phones, smartphones, sensor devices, meters, vehicles, home appliances, medical devices, media players, cameras, or any type of consumer electronics, such as but not limited to televisions, radios, lighting devices, tablets, laptops, or personal computers. A wireless communication device can be a portable, handheld, computer-contained, or vehicle-mounted mobile device capable of voice and / or data communications over a wireless connection.

[0040] Network node: As used herein, a "network node" is any node belonging to the RAN or core network of a cellular communication network / system.

[0041] Please note that the description given herein focuses on 3GPP cellular communication systems, and therefore 3GPP terminology or terminology similar to 3GPP terminology is often used. However, the concepts disclosed herein are not limited to 3GPP systems.

[0042] Note that in the description of this document, the term "cell" may be mentioned; however, particularly for 5G NR concepts, beams may be used instead of cells, and therefore it is important to note that the concepts described in this document apply equally to cells and beams.

[0043] In the current 3GPP specification, the Location Management Function (LMF) uses the Subscription Permanent Identifier (SUPI) to identify the User Equipment (UE). However, when the UE performs device discovery over the PC5 reference point, the SUPI is not used in the discovery message. Instead, the application layer or service layer user identity (ID) is usually used in the PC5 discovery message. Therefore, if the LMF wants to inform the target UE of the reference UE ID, the SUPI cannot be provided. The LMF needs to provide the target UE with the application layer user ID of the reference UE, or provide the target UE with the application layer user ID of the reference UE, as shown in solution #21 above. The problem is that there is currently no process for the LMF to obtain the application layer user ID of the UE.

[0044] In another scenario, the target UE can select the reference UE by itself and send the reference UE ID to the LMF, as shown in Solution #7, step 5. In this case, the problem is that there is currently no process for the LMF to find the SUPI of the reference UE from its application layer user ID. Solution #7 mentions that the fifth generation (5G) Direct Discovery Name Management Function (DDNMF) can help, but no specific details are provided.

[0045] Disclosed herein are systems and methods for addressing the above and / or other challenges. In one embodiment, a new 5G DDNMF service is disclosed that provides an ID mapping between a SUPI and an application layer or service layer user ID. Specifically, with respect to sidelink ranging / positioning, in one embodiment, the UE uses a sidelink ranging application user ID (SRAUID) in a PC5 discovery message. In one embodiment, the SRAUID is assigned by an application server. In another embodiment, the SRAUID is assigned by the 5G DDNMF. In one embodiment, the UE registers with or requests its SRAUID from the 5G DDNMF.

[0046] Embodiments of the solution described herein have many advantages over existing solutions. For example, embodiments of the solution described herein enable the LMF to identify the UE when the UE performs device discovery over the PC5 reference point (ie, over the sidelink).

[0047] Figure 3An example of a cellular communication system 300 in which embodiments of the present disclosure may be implemented is shown. In the embodiments described herein, the cellular communication system 300 is a 5G system (5GS), including a next generation RAN (NG-RAN) and a 5G core network (5GC); however, the embodiments disclosed herein may be used for any cellular communication system that utilizes a side link for discovery. In this example, the RAN includes base stations 302-1 and 302-2, including NR base stations (gNBs) and optional next generation eNBs (ng-eNBs) (e.g., LTE RAN nodes connected to 5GC) in the 5GS, controlling corresponding (macro) cells 304-1 and 304-2. Herein, base stations 302-1 and 302-2 are generally referred to collectively as base stations 302, and individually as base stations 302. Similarly, herein, (macro) cells 304-1 and 304-2 are generally referred to collectively as (macro) cells 304, and individually as (macro) cells 304. The RAN may also include a plurality of low-power nodes 306-1 to 306-4, which control corresponding small cells 308-1 to 308-4. The low-power nodes 306-1 to 306-4 may be small base stations (e.g., micro base stations or femto base stations) or RRHs, etc. It is worth noting that, although not shown, one or more of the small cells 308-1 to 308-4 may be provided alternatively by the base station 302. Herein, the low-power nodes 306-1 to 306-4 are generally referred to as low-power nodes 306, and are individually referred to as low-power nodes 306. Similarly, herein, the small cells 308-1 to 308-4 are generally referred to as small cells 308, and are individually referred to as small cells 308. The cellular communication system 300 also includes a core network 310, which is referred to as 5GC in 5GS. The base station 302 (and the optional low-power node 306) are connected to the core network 310.

[0048] Base station 302 and low power node 306 provide services to wireless communication devices 312-1 to 312-5 in respective cells 304 and 308. Wireless communication devices 312-1 to 312-5 are generally referred to herein as wireless communication devices 312 in general and individually as wireless communication devices 312. In the following description, wireless communication device 312 is often a UE, but the present disclosure is not limited thereto.

[0049] Figure 4 A wireless communication system of a 5G network architecture consisting of core network functions (NF) is shown. Figure 4 can be seen as Figure 3 Specifically, Figure 4 According to 3GPPTR 23.700-86 Figure 4.3.1-1 embodiment of a system 300 based on a reference architecture for sidelink positioning and ranging services for non-roaming and same public land mobile network (PLMN) operation. Please note that this is just an example. For example, the system 300 may alternatively use one of the other reference architectures defined in 3GPP TR 23.700-86 for inter-PLMN operation or inter-PLMN operation with roaming.

[0050] like Figure 4 As shown, the system 300 includes UE 312 (referred to as UE A, UE B, UE C and UE D) and corresponding PC5 interfaces (i.e., side links) therebetween. In this example, UE A and UE B have Uu interfaces to the RAN (e.g., to their respective base stations 302). As shown, in this example, the core network 310 includes various NFs, including a location management function (LMF) 400, an NRF 402, a UDR 404, an AMF 406, an SMF 408, a UPF 410, a GMLC 412, and an LRF 414, a UDM 416, a PCF 418, a NEF 420, and a 5GDDNMF 422.

[0051] Note that a NF can be implemented as a network element on dedicated hardware, as a software instance running on dedicated hardware, or as a virtualized function instantiated on an appropriate platform (e.g., cloud infrastructure).

[0052] In the following sections, how the 5G DDNMF 422 provides a service for mapping a SUPI to an application layer / service layer user ID is described in detail. Sidelink (SL) ranging is used as an example use case. Specifically, in the first section below, embodiments related to how the 5G DDNMF 422 establishes an association between a SUPI and an application layer / service layer user ID are described. In the second section below, embodiments related to how the 5G DDNMF 422 provides a service for mapping a SUPI to an application layer / service layer user ID are described. In the third section below, SL ranging is used as a use case and embodiments related to how the LMF 400 uses such a service to obtain a UE SUPI or an application layer / service layer ID are described. Application layer / service layer user ID registration to 5G DDNMF

[0053] In one embodiment, in the SL ranging use case, the UE 312 uses a Sidelink Ranging Application User ID (SRAUID) in the PC5 discovery message. Note that this document uses the term "SRAUID" as an example; however, any name may be used for this ID. Therefore, as used herein, the term "SRAUID" should be understood to refer to this ID, regardless of the actual name of this ID. The SRAUID may be assigned by the application server, or may be assigned by the PCF 418 or the 5G DDNMF 422.

[0054] Figure 5 A process according to an example embodiment of the present disclosure is shown. The process involves UE 312, 5G DDNMF 422 and UDM 500. Figure 5 The process steps are described below.

[0055] Step 502: UE 312 sends a registration request to 5G DDNMF 422 using its SUPI, application ID and / or SL location service code. If UE 312 obtains its SRAUID from AF (application function, application server) or PCF 418, UE 312 registers the SRAUID in 5G DDNMF 422. In other words, if UE 312 obtains its SRAUID from AF or PCF 418, UE 312 includes the SRAUID in the registration request. In this regard, SRAUID is an optional element of the registration request. If the SRAUID should be assigned by 5G DDNMF 422, UE 312 does not include any SRAUID in the registration request.

[0056] Step 504: 5G DDNMF 422 obtains UE subscription data of UE 312 from UDM 500, and uses the UE subscription data to check whether UE 312 is authorized to use SL ranging / positioning services.

[0057] Step 505 (optional): The 5G DDNMF 422 may contact the PCF 418 or AF to check whether the UE 312 is authorized to use the SL ranging / positioning service for a specific SRAUID, application ID and / or SL positioning service code.

[0058] For example, if the SRAUID is assigned by the AF, the 5G DDNMF 422 can issue a Naf_ProSe_DiscoveryAuthorization request to the AF, which contains the SRAUID, application ID, and optional SL positioning service code. If the SRAUID is a valid user ID using the SL ranging / positioning service, the AF will respond with the ProSeDiscovery UE ID (PDUID) (defined in 3GPP TS23.304) registered by the UE 312 in the AF. If the PDUID from the AF matches the PDUID from the PCF 418, the 5G DDNMF 422 will use the SRAUID as a valid SRAUID associated with the UE 312.

[0059] Step 506: If step 504 and step 505 are normal, if 5G DDNMF 422 should allocate SRAUID for UE 312, 5G DDNMF 422 generates SRAUID for UE 312. Note that 5G DDNMF 422 can generate SRAUID for all applications using SL ranging / positioning, or can generate SRAUID for each application.

[0060] Step 507: Regardless of whether the SRAUID is generated by the 5G DDNMF 422 or provided by the UE 312 in the registration request of step 502, the 5G DDNMF 422 maintains the mapping between the UE SUPI and the SRAUID, and optionally also maintains the Application ID and / or SL Location Service Code.

[0061] Step 508: 5G DDNMF 422 sends a response to UE 312, indicating whether the registration is successful or rejected. In addition, if 5G DDNMF 422 generates a SRAUID in step 506, 5G DDNMF 422 may also send the generated SRAUID to UE 312 in the response.

[0062] Step 510: If the ID is assigned by the 5G DDNMF 422, the UE 312 may register its SRAUID in the application server.

[0063] If the SRAUID is assigned by PCF 418 or 5G DDNMF 422, it may contain information about the Home PLMN (HPLMN) of UE 312.

[0064] In an alternative embodiment, another user ID other than SRAUID, such as a sidelink ranging discovery user ID (SRDUID), is assigned by PCF 418 or 5G DDNMF 422. This user ID can be used within the 5GC and used for SL positioning at the PC5 interface and contains the HPLMN information of the UE. In this regard, in all the above steps, SRAUID can be replaced by SRAUID and / or SRDUID.

[0065] The 5G DDNMF 422 maintains the mapping between UE SUPI and SRAUID and / or SRDUID. New service of 5G DDNMF maps SUPI to application layer / service layer user ID

[0066] In one embodiment, a new service of the 5G DDNMF 422 is provided to map the SUPI to the application layer / service layer user ID. Herein, this new service is referred to as the N5g-ddnmf_UEID_Retrieval service; however, this name is just an example. This service may use other names.

[0067] Figure 6 The process of a new service when the UE 312 belongs to the same PLMN of the 5G DDNMF 422 according to one embodiment of the present disclosure is shown. The process involves the 5G DDNMF 422 and the NF consumer 600. The process steps are described as follows.

[0068] When the UE belongs to the PLMN of the 5G DDNMF 422, this means that the 5G DDNMF 422 should have the mapping between SUPI and SRAUID itself, i.e. it does not need to query the 5G DDNMF of another PLMN.

[0069] Step 602: The NF consumer 600 of the N5g-ddnmf_UEID_Retrieval service sends a request to the 5GDDNMF 422. If the NF consumer 600 wants to retrieve the UE SUPI, the SRAUID and the application ID and / or the SL location service code are included in the request. If the NF consumer 600 wants to retrieve the SRAUID of the UE 312, the SUPI and the application ID and / or the SL location service code are included in the request.

[0070] Step 604: 5G DDNMF 422 sends SRAUID or SUPI according to the request.

[0071] In an alternative embodiment, SRAUID is replaced with SRAUID and / or SRDUID from the above steps.

[0072] Figure 7 A flow according to another example embodiment is shown, where the NF consumer 700 wants to obtain the UE SRAUID, but the UE's home PLMN (HPLMN) is different from the PLMN of the current 5G DDNMF 422. The flow involves the (current) 5G DDNMF 422, the NF consumer 700 and another 5G DDNMF 702 of the UE's HPLMN. The flow steps are described as follows.

[0073] Step 704: The 5G DDNMF 422 receives the N5g-ddnmf_UEID_Retrieval request, but the SUPI included in the request belongs to another PLMN. This means that the current 5G DDNMF 422 has no UE context or ID mapping.

[0074] Step 706: The 5G DDNMF 422 sends a N5g-ddnmf_UEID_Retrieval request to the 5G DDNMF 702 of the HPLMN of the UE.

[0075] Step 708 and step 710: The 5G DDNMF 702 of the HPLMN of the UE sends the SRAUID of the UE back to the first 5G DDNMF 422. The first 5G DDNMF 422 sends the SRAUID back to the NF consumer 700.

[0076] In an alternative embodiment, SRAUID is replaced with SRAUID and / or SRDUID from the above steps.

[0077] Figure 8 A flow according to another example embodiment is shown, where the NF consumer 800 wants to obtain the UE SUPI, but the HPLMN of the UE is different from the PLMN of the current 5G DDNMF 422. The flow involves the 5G DDNMF 422, the NF consumer 800, the 5G DDNMF 802 of the HPLMN of the UE, and the AF 804. The flow steps are described as follows.

[0078] Step 806: The 5G DDNMF 422 receives the N5g-ddnmf_UEID_Retrieval request, but cannot recognize the SRAUID in the request. It is possible that the corresponding UE 312 belongs to another PLMN, so the current 5G DDNMF 422 has no UE context or ID mapping.

[0079] Step 808: The 5G DDNMF 422 sends a Naf_ProSe_DiscoveryAuthorization request to the application server / AF 804, where the request includes the SRAUID.

[0080] Naf_ProSe_DiscoveryAuthorization is defined in TS23.304.

[0081] Step 810: If the application server has a context for the SRAUID, the application server will reply to the 5G DDNMF 422 with the PDUID (defined in TS23.304).

[0082] Step 812: If the 5G DDNMF 422 obtains the PDUID from the application server, it can obtain the UE's HPLMN information. Using this information, the 5G DDNMF 422 sends a N5g-ddnmf_UEID_Retrieval request to the 5G DDNMF 802 of the UE's HPLMN, with the PDUID and / or SRAUID.

[0083] Step 814 and step 816: The 5G DDNMF 802 of the HPLMN of the UE sends the SUPI of the UE back to the first 5G DDNMF 422. The first 5G DDNMF 422 sends the SUPI back to the NF consumer 800.

[0084] In an alternative embodiment, if the SRAUID contains HPLMN information or the SRDUID is received in step 806 (instead of steps 808-810), the 5G DDNMF 422 directly contacts the 5G DDNMF 802 of the HPLMN and sends the N5g-ddnmf_UEID_Retrieval request to the 5G DDNMF 802 of the UE's home PLMN (HPLMN). Using N5g-ddnmf_UEID_Retrieval service in SL ranging / positioning scenarios

[0085] Fig. 9 An example embodiment of a process is shown in which the LMF 400 receives a positioning / ranging request for a target UE 902. The LMF 400 also has information indicating that a specific reference UE 900 should be used for SL ranging / positioning. This process steps are described as follows.

[0086] Step 904 and step 906: The target UE 902 and the 5G DDNMF 422 perform for the target UE 902 Figure 5 The specific details are the same as described above. Similarly, reference is made to UE 900 and 5G DDNMF 422 for UE 900 to perform Figure 5 The registration process.

[0087] Step 908: LMF 400 receives the positioning / ranging request of target UE 902. LMF 400 also has information indicating that reference UE 900 should be used for SL ranging / positioning. However, since LMF 400 only has the SUPI of reference UE 900, LMF 400 needs to obtain the SRAUID of reference UE 900.

[0088] Step 910: LMF 400, as a consumer of the N5g-ddnmf_UEID_Retrieval service, retrieves the SRAUID of the reference UE 900, as described above, for example, Figure 6 , Figure 7 or Figure 8 .

[0089] Step 912: LMF 400 sends a SL ranging / positioning request to the target UE 902 using the SRAUID of the reference UE.

[0090] Steps 914-920: These steps are shown only to ensure the completeness of the process. These details are outside the scope of this disclosure.

[0091] Fig.10 A flow according to another example embodiment is shown, where the LMF 400 receives a positioning / ranging request for a target UE 1002, but it does not have information of a reference UE 1000. The flow steps are as follows.

[0092] Step 1004 and step 1006: The target UE 1002 and the 5G DDNMF 422 perform Figure 5 The specific details are the same as described above. Similarly, reference is made to UE 1000 and 5G DDNMF 422 for UE 1000 to perform Figure 5 The registration process.

[0093] Steps 1008-1014: Similar to steps 1–5 in solution #7 of TR 23.700-86.

[0094] Step 1016: LMF 400, as a consumer of N5g-ddnmf_UEID_Retrieval service, retrieves the SUPI of reference UE 1000, as described above, for example, reference Figure 6 , Figure 7 or Figure 8 .

[0095] Step 1018 and step 1020: These steps are shown only to ensure the completeness of the process. These details are outside the scope of this disclosure. Further description

[0096] Fig.11 1 is a schematic block diagram of a network node 1100 according to some embodiments of the present disclosure. Optional features are represented by dashed boxes. The network node 1100 may be, for example, a core network node that implements a NF (e.g., 5G DDNMF 422, LMF 400, NF consumer 600, NF consumer 700, 5G DDNMF 702, NF consumer 800, 5G DDNMF 802, etc.), or a network node that implements all or part of the functions of a NF (e.g., all or part of the functions of the 5G DDNMF 422, LMF 400, NF consumer 600, NF consumer 700, 5G DDNMF 702, NF consumer 800, 5G DDNMF 802, etc. described herein). As shown, the network node 1100 includes one or more processors 1104 (e.g., a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), and / or the like), a memory 1106, and a network interface 1108. In this document, the one or more processors 1104 are also referred to as processing circuits. The one or more processors 1104 operate to provide one or more functions of the network node 1100 described herein (e.g., one or more functions of the 5G DDNMF 422, LMF 400, NF consumer 600, NF consumer 700, 5G DDNMF 702, NF consumer 800, or 5G DDNMF 802 described herein). In some embodiments, the function is implemented in software stored in, for example, the memory 1106 and executed by one or more processors 1104.

[0097] Fig.121 is a schematic block diagram of a virtualized embodiment of a network node 1100 according to some embodiments of the present disclosure. Again, optional features are represented by dashed boxes. As used herein, a "virtualized" network node is an implementation of a network node 1100 in which at least a portion of the functionality of the network node 1100 is implemented as a virtual component (e.g., by a virtual machine executed on a physical processing node in the network). As shown, in this example, the network node 1100 includes one or more processing nodes 1200 coupled to a network 1202 or included as part of the network 1202. Each processing node 1200 includes one or more processors 1204 (e.g., CPU, ASIC, FPGA, etc.), a memory 1206, and a network interface 1208. In this example, the functionality 1210 of the network node 1100 described herein (e.g., one or more functions of the 5G DDNMF 422, LMF 400, NF consumer 600, NF consumer 700, 5G DDNMF 702, NF consumer 800, or 5G DDNMF 802 described herein) is implemented at one or more processing nodes 1200, or distributed in any desired manner across two or more processing nodes 1200. In some specific embodiments, some or all of the functionality 1210 of the network node 1100 described herein is implemented as a virtual component executed by one or more virtual machines implemented in a virtual environment hosted by the processing node 1200.

[0098] In some embodiments, a computer program is provided, the computer program including instructions, when the instructions are executed by at least one processor, so that the at least one processor performs the functions of the network node 1100 of any embodiment described herein, or the functions of a node (e.g., processing node 1200) that implements one or more functions 1210 of the network node 1100 in a virtual environment. In some embodiments, a carrier including the aforementioned computer program product is provided. The carrier is one of an electrical signal, an optical signal, a radio signal, or a computer-readable storage medium (e.g., a non-transitory computer-readable medium, such as a memory).

[0099] Fig.13 1 is a schematic block diagram of a network node 1100 according to some other embodiments of the present disclosure. The network node 1100 includes one or more modules 1300, each of which is implemented in software. The modules 1300 provide the functions of the network node 1100 described herein. The discussion also applies to Fig.12 processing nodes 1200 , wherein module 1300 may be implemented on one of processing nodes 1200 , or distributed on multiple processing nodes 1200 .

[0100] Fig.141400 is a schematic block diagram of a wireless communication device 1400 according to some embodiments of the present disclosure. As shown, the wireless communication device 1400 includes one or more processors 1402 (e.g., CPU, ASIC, FPGA, etc.), a memory 1404, and one or more transceivers 1406, each transceiver 1406 including one or more transmitters 1408 and one or more receivers 1410, coupled to one or more antennas 1412. The transceiver 1406 includes a radio front-end circuit connected to the antenna 1412, which is configured to adjust the signals transmitted between the antenna 1412 and the processor 1402, as understood by a person of ordinary skill in the art. Herein, the processor 1402 is also referred to as a processing circuit. Herein, the transceiver 1406 is also referred to as a radio circuit. In some embodiments, the functions of the wireless communication device 1400 described above may be implemented in whole or in part in software, which is, for example, stored in the memory 1404 and executed by the processor 1402. It should be noted that the wireless communication device 1400 may include Fig.14 Additional components not shown, such as one or more user interface components (e.g., input / output interfaces, including displays, buttons, touch screens, microphones, speakers, and / or the like and / or any other components for allowing information to be entered into the wireless communication device 1400 and / or allowing information to be output from the wireless communication device 1400), power sources (e.g., batteries and associated power circuits), etc.

[0101] In some embodiments, a computer program is provided, the computer program including instructions, when the instructions are executed by at least one processor, the at least one processor performs the functions of the wireless communication device 1400 according to any embodiment described herein. In some embodiments, a carrier including the aforementioned computer program product is provided. The carrier is one of an electric signal, an optical signal, a radio signal or a computer-readable storage medium (e.g., a non-transitory computer-readable medium, such as a memory).

[0102] Fig.15 1 is a schematic block diagram of a wireless communication device 1400 according to some other embodiments of the present disclosure. The wireless communication device 1400 includes one or more modules 1500, each of which is implemented in software. The modules 1500 provide the functions of the wireless communication device 1400 described herein.

[0103] Any suitable steps, methods, features, functions or benefits disclosed herein may be performed by one or more functional units or modules of one or more virtual devices. Each virtual device may include multiple such functional units. These functional units may be implemented by processing circuits, which may include one or more microprocessors or microcontrollers and other digital hardware, which may include digital signal processors (DSPs), dedicated digital logic, etc. The processing circuit may be configured to execute program codes stored in a memory, which may include one or more types of memory, such as read-only memory (ROM), random access memory (RAM), cache, flash memory device, optical storage device, etc. The program code stored in the memory includes program instructions for executing one or more telecommunications and / or data communication protocols and instructions for executing one or more technologies described herein. In some implementations, the processing circuit may be used to enable each functional unit to perform the corresponding functions of one or more embodiments of the present disclosure.

[0104] Although the processes in the figures may show a specific order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (for example, alternative embodiments may perform operations in a different order, combine certain operations, overlap certain operations, etc.).

[0105] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered to fall within the scope of the concepts disclosed herein.

Claims

1. A method performed by a network node, comprising: ● Receive (602;) from the network function NF consumer (600); 704； 806) A service request, wherein the service request includes any of the following: o A subscription permanent identifier SUPI (312) of a specific user equipment UE; or o A sidelink ranging application user identifier SRAUID of the specific UE (312) and / or a sidelink ranging discovery user identifier SRDUID of the specific UE (312); ● Sending (604; 710; 816) a response to the NF consumer (600), the response including any of the following: o If the service request includes a SUPI of the specific UE (312), a SRAUID mapped to the SUPI of the specific UE (312) and / or a SRDUID mapped to the SUPI of the specific UE (312); or o If the service request includes the SRAUID and / or SRDUID of the specific UE (312) and / or the SRDUID of the specific UE (312), the SUPI mapped to the SRAUID and / or SRDUID of the specific UE (312).

2. The method according to claim 1, wherein: The service request includes the SUPI of the specific UE (312) and additional information, the additional information including one or both of: an application ID and a sidelink positioning service code; and The response includes the SRAUID and / or SRDUID mapped to the SUPI.

3. The method according to claim 1 or 2, wherein: The network node stores a mapping between the SUPI of the specific UE (312) and the SRAUID and / or SRDUID of the specific UE (312).

4. The method according to claim 1 or 2, wherein: The home public land mobile network HPLMN of the specific UE (312) is different from the public land mobile network PLMN where the network node is located, the service request includes the SUPI of the specific UE (312), and the method further includes: sending (706) the service request to a second network node (702) in the HPLMN of the UE (312); and A response is received (708) from the second network node (702), the response from the second network node (702) including a SRAUID mapped to the SUPI of the specific UE (312) and / or a SRDUID mapped to the SUPI of the specific UE (312).

5. The method according to claim 1 or 2, wherein: The home public land mobile network HPLMN of the specific UE (312) is different from the public land mobile network PLMN where the network node is located, the service request includes the SRAUID and / or SRDUID of the specific UE (312), and the method further includes: sending (812) the service request to a second network node (802) in the HPLMN of the UE (312); and A response is received (814) from the second network node (802), the response from the second network node (802) including the SUPI mapped to the SRAUID and / or SRDUID of the specific UE (312).

6. The method according to any one of claims 1 to 5, before receiving the service request, further comprising: receiving (502) a registration request from the specific UE (312), the registration request comprising the SUPI of the specific UE (312) and additional information, the additional information comprising information indicating a service associated with the registration request and an application identification ID; determining (504) whether the particular UE (312) is authorized to use the service; as well as In response to determining (504) that the particular UE (312) is authorized to use the service: A mapping between the SUPI of the specific UE (312) and a SRAUID and / or SRDUID of the specific UE (312) is stored (507), the SRAUID and / or SRDUID of the specific UE (312) being included in a registration request or generated by the network node.

7. The method according to claim 6, wherein: The SRAUID and / or SRDUID of the specific UE (312) is included in the registration request.

8. The method of claim 6, further comprising generating (506) the SRAUID and / or SRDUID for the specific UE (312).

9. The method of claim 8, further comprising sending (508) a registration response to the specific UE (312), the registration response comprising the SRAUID and / or SRDUID of the specific UE (312).

10. The method according to any one of claims 1 to 9, wherein: The NF consumer is the Location Management Function LMF (400).

11. The method according to any one of claims 1 to 10, wherein: The service request is associated with a sidelink ranging or positioning procedure, and the specific UE (312) is a UE for which sidelink positioning is enabled for the sidelink ranging or positioning procedure.

12. The method according to any one of claims 1 to 11, wherein the network node is a network node implementing DDNMF.

13. A network node, adapted to: ● receiving (602; 704; 806) a service request from a network function NF consumer (600), the service request comprising any of the following: o a subscription permanent identifier SUPI of a specific user equipment UE (312); or o A sidelink ranging application user identifier SRAUID of the specific UE (312) and / or a sidelink ranging discovery user identifier SRDUID of the specific UE (312); ● Sending (604; 710; 816) a response to the NF consumer (600), the response including any of the following: o If the service request includes a SUPI of the specific UE (312), a SRAUID mapped to the SUPI of the specific UE (312) and / or a SRDUID mapped to the SUPI of the specific UE (312); or o If the service request includes the SRAUID and / or SRDUID of the specific UE (312) and / or the SRDUID of the specific UE (312), the SUPI mapped to the SRAUID and / or SRDUID of the specific UE (312).

14. The network node according to claim 13, further adapted to perform the method according to any one of claims 2 to 12.

15. A network node comprising a processing circuit configured to cause the network node to: ● receiving (602; 704; 806) a service request from a network function NF consumer (600), the service request comprising any of the following: o a subscription permanent identifier SUPI of a specific user equipment UE (312); or o A sidelink ranging application user identifier SRAUID of the specific UE (312) and / or a sidelink ranging discovery user identifier SRDUID of the specific UE (312); ● Sending (604; 710; 816) a response to the NF consumer (600), the response including any of the following: o If the service request includes a SUPI of the specific UE (312), a SRAUID mapped to the SUPI of the specific UE (312) and / or a SRDUID mapped to the SUPI of the specific UE (312); or o If the service request includes the SRAUID and / or SRDUID of the specific UE (312) and / or the SRDUID of the specific UE (312), the SUPI mapped to the SRAUID and / or SRDUID of the specific UE (312).

16. The network node according to claim 15, wherein the processing circuit is further configured to cause the network node to perform the method according to any one of claims 2 to 12.

17. A computer program comprising instructions which, when executed on at least one processor, cause the processor to perform the method according to any one of claims 1 to 12.

18. A carrier comprising the computer program according to claim 17, wherein the carrier is one of an electric signal, an optical signal, a radio signal or a computer-readable storage medium.

19. A non-transitory computer-readable medium comprising instructions executable by a processing circuit of a network node, whereby the network node is operable to: ● receiving (602; 704; 806) a service request from a network function NF consumer (600), the service request comprising any of the following: o a subscription permanent identifier SUPI of a specific user equipment UE (312); or o A sidelink ranging application user identifier SRAUID of the specific UE (312) and / or a sidelink ranging discovery user identifier SRDUID of the specific UE (312); ● Sending (604; 710; 816) a response to the NF consumer (600), the response including any of the following: o If the service request includes a SUPI of the specific UE (312), a SRAUID mapped to the SUPI of the specific UE (312) and / or a SRDUID mapped to the SUPI of the specific UE (312); or o If the service request includes the SRAUID and / or SRDUID of the specific UE (312) and / or the SRDUID of the specific UE (312), the SUPI mapped to the SRAUID and / or SRDUID of the specific UE (312).

20. A method performed by a user equipment UE (312), the method comprising: Sending (502) a registration request to a network node (422), the registration request comprising: o a subscription permanent identifier SUPI of the UE (312); and o The sidelink ranging application user identifier SRAUID of the specific UE (312) and / or the sidelink ranging discovery user identifier SRDUID of the specific UE (312).

21. A user equipment UE (312), adapted to: Sending (502) a registration request to a network node (422), the registration request comprising: o a subscription permanent identifier SUPI of the UE (312); and o The sidelink ranging application user identifier SRAUID of the specific UE (312) and / or the sidelink ranging discovery user identifier SRDUID of the specific UE (312).

22. A user equipment UE (312), comprising: one or more transmitters; one or more receivers; as well as processing circuitry associated with the one or more transmitters and the one or more receivers, the processing circuitry being configured to cause the UE to send (502) a registration request to a network node (422), the registration request comprising: ● a subscription permanent identifier SUPI of the UE (312); as well as The sidelink ranging application user identifier SRAUID of the specific UE (312) and / or the sidelink ranging discovery user identifier SRDUID of the specific UE (312).

23. A method performed by a user equipment UE (312), the method comprising: sending (502) a registration request to a network node (422), the registration request comprising a subscription permanent identifier (SUPI) of the UE (312); as well as A registration response is received (508) from a network node (422), the registration response including a sidelink ranging application user identifier SRAUID assigned to the UE (312) and / or a sidelink ranging discovery user identifier SRDUID assigned to the UE (312).

24. A user equipment UE (312), adapted to: sending (502) a registration request to a network node (422), the registration request comprising a subscription permanent identifier (SUPI) of the UE (312); and A registration response is received (508) from the network node (422), the registration response including a sidelink ranging application user identifier SRAUID assigned to the UE (312) and / or a sidelink ranging discovery user identifier SRDUID assigned to the UE (312).

25. A user equipment UE (312), comprising: one or more transmitters; one or more receivers; as well as processing circuitry associated with the one or more transmitters and the one or more receivers, the processing circuitry being configured to cause the UE to: sending (502) a registration request to a network node (422), the registration request comprising a subscription permanent identifier (SUPI) of the UE (312); as well as A registration response is received (508) from the network node (422), the registration response including a sidelink ranging application user identifier SRAUID assigned to the UE (312) and / or a sidelink ranging discovery user identifier SRDUID assigned to the UE (312).

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