Network node indicating or storing absolute location information

Abstract

There is provided an apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least: generate a sidelink (SL) discovery message indicating that absolute location information is available, the absolute location information indicating an absolute location of the apparatus; at least sending an SL discovery message to the terminal device; and indicating at least one of the absolute location information or the network node storing the absolute location information to the terminal device.

Description

TECHNICAL FIELD

[0001] Various example embodiments generally relate to cellular communications. More specifically, various examples relate to network nodes indicating or storing absolute position information in sidelink positioning. BACKGROUND

[0002] Sidelink positioning (or lateral positioning) is a procedure for determining the position of one or more terminal devices based on at least sending one or more reference signals between different UEs. Relative positioning or positioning can be performed without absolute position information, but absolute positioning or positioning can require the absolute position of other UEs to be known. It can therefore be beneficial to provide a solution in a sidelink communication system that enables sharing of absolute position information. SUMMARY

[0003] According to some aspects, the subject matter of the independent claims is provided. Some further aspects are defined in the dependent claims. Embodiments not falling within the scope of the claims are to be interpreted as examples facilitating the understanding of the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0004] In the following, the present application will be described in more detail with reference to embodiments and to accompanying drawings, wherein Figure 1 A network to which one or more embodiments are applicable is presented; Figure 2 An example of sidelink positioning to which one or more embodiments are applicable is illustrated; Figure 3A , 3B , 4, 5A, 5B, 5C, 6A, 6B, 6C, and 7 illustrate some example embodiments; and Figure 8 and 9 An apparatus according to some embodiments is illustrated. DETAILED DESCRIPTION

[0005] The following embodiments are exemplary. Although the specification can A or B, A and B, or A and / or B. For purposes of the present disclosure, the phrase “A, B, and / or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).

[0006] It should be understood that, although the terms“first” and“second” and the like can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the example embodiments.

[0007] The described embodiments can be implemented in a radio system such as a radio system comprising at least one of the following radio access technologies (RATs): Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile Communications (GSM, 2G), GSM EDGE Radio Access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband code division multiple access (W-CDMA), High Speed Packet Access (HSPA), Long Term Evolution (LTE), LTE-Advanced, and Enhanced LTE (eLTE). The term“eLTE” denotes here an LTE evolution connected to a 5G core. LTE is also referred to as Evolved UMTS Terrestrial Radio Access (EUTRA) or Evolved UMTS Terrestrial Radio Access Network (EUTRAN). The term“resource” can refer to a radio resource such as a physical resource block (PRB), a radio frame, a subframe, a time slot, a subband, a frequency region, a subcarrier, a beam, etc. The terms“transmit” and / or“receive” can refer to wirelessly transmitting and / or receiving over a radio resource via a wireless propagation channel.

[0008] However, the embodiments are not limited to the system / RAT given as an example, but a person skilled in the art can apply the solution to other communication systems / networks having the necessary properties. Some examples of suitable communication networks include 5G networks and / or 6G networks. The 3GPP solution for 5G is referred to as New Radio (NR). 6G is envisioned to be a further development of 5G. NR has been conceived to use Multiple Input Multiple Output (MIMO) multi-antenna transmission techniques, more base stations or nodes than the current network deployment of LTE, a so-called small cell concept, including operation of macro sites in cooperation with smaller local area access nodes, and possibly also exploitation of various radio technologies for better coverage and enhanced data rates. 5G will likely include more than one radio access technology / radio access network (RAT / RAN), each optimized for certain use cases and / or spectrums. 5G mobile communications can have a wider range of use cases and related applications, including video streaming, augmented reality, different ways of sharing data, and various forms of machine type applications including vehicle safety, different sensors, and real-time control. 5G is expected to have multiple radio interfaces, i.e., sub-6 GHz, cmWave, and mmWave, and be integrable with existing legacy radio access technologies such as LTE.

[0009] The current architecture in LTE networks is distributed in the radio and centralized in the core network. Low latency applications and services in 5G can require bringing the content close to the radio, which leads to local breakouts and multi-access edge computing (MEC). 5G enables analytics and knowledge generation to occur at the source of the data. This approach requires leveraging resources that can not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content close to the cellular subscriber for faster response time. Edge computing encompasses a wide variety of technologies, such as wireless sensor networks, mobile data acquisition, mobile signature analysis, cooperative distributed peer-to-peer self-organizing networking and processing, which can also be classified as local cloud / fog computing and grid / mesh computing, dew computing, mobile edge computing, micro clouds, distributed data storage and retrieval, self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and / or delay critical), critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications). Edge cloud can be brought into the RAN by utilizing network function virtualization (NVF) and software-defined networking (SDN). Using edge cloud can mean access node operations to be executed at least partly in a server, host, or node that is operably coupled to a remote radio head or base station that includes radio parts. Network slicing allows multiple virtual networks to be created on top of a common shared physical infrastructure. The virtual networks are then customized to meet the specific needs of applications, services, devices, customers, or operators.

[0010] In wireless communications, node operations can be performed at least partly in a central / centralized unit CU (e.g., a server, host, or node) operably coupled to a distributed unit DU (e.g., a radio head / node). Node operations can also be distributed among multiple servers, nodes, or hosts. It will also be appreciated that the distribution of effort between core network operations and base station operations can vary depending on implementation. Thus, the 5G network architecture can be based on a so-called CU-DU split. One gNB-CU controls several gNB-DUs. The term “gNB” in 5G can correspond to the eNB in LTE. The gNB(s) can communicate with one or more UEs. The gNB-CU (central node) can control multiple spatially separated gNB-DUs, acting at least as a transmit / receive (Tx / Rx) node. However, in some embodiments, the gNB-DU (also referred to as DU) can comprise, for example, the Radio Link Control (RLC), Medium Access Control (MAC) layers, and the Physical (PHY) layer, while the gNB-CU (also referred to as CU) can comprise layers above the RLC layer, such as the Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC), and Internet Protocol (IP) layers. Other functional splits are also possible. The skilled person is familiar with the OSI model and the functions within each layer.

[0011] In embodiments, the server or CU can generate a virtual network through which the server communicates with the radio node. In general, virtual networking can involve the process of combining hardware and software network resources and network functionality into a single, software-based management entity (virtual network). Such a virtual network can provide flexible distribution of operations between the server and the radio head / node. Indeed, any digital signal processing tasks can be performed in the CU or DU, and the border of shifting responsibilities between the CU and the DU can be chosen according to implementation.

[0012] Some other possible technology advancements to be used are Software-Defined Networking (SDN), Big Data, and All-IP, to mention a few non-limiting examples. For example, network slicing can be in the form of a virtual network architecture behind the same principles of Software-Defined Networking (SDN) and Network Function Virtualization (NFV) used in fixed networks. SDN and NFV can provide greater network flexibility by allowing traditional network architecture to be divided into virtual elements that can be linked (also by software). Network slicing allows multiple virtual networks to be created on top of a common shared physical infrastructure. The virtual networks are then customized to meet the specific needs of an application, service, device, customer, or operator.

[0013] Multiple gNBs (access points / nodes) each comprising a CU and one or more DUs can be connected to each other via an Xn interface over which gNBs can negotiate. The gNBs can also be connected to a 5G core network (5GC) over a next generation (NG) interface, which can be the 5G equivalent of the core network of LTE. Such 5G CU-DU split architecture can be implemented using a cloud / server such that the CU with higher layers is located in the cloud and the DU is closer or comprises the actual radio and antenna units. Similar plans are ongoing for LTE / LTE-A / eLTE as well. When both eLTE and 5G will use similar architectures in the same cloud hardware (HW), the next step can be to combine the software (SW) such that one common SW controls both radio access networks / technologies (RAN / RAT). This can allow new ways to control the radio resources of both RANs. Furthermore, it is possible to have a configuration in which the complete protocol stack is controlled by the same HW as the CU and processed by the same radio units as the CU.

[0014] It should also be understood that the labor distribution between core network operations and base station operations can be different from the labor distribution of LTE or even not existent. Some other technology advancements that can be used are big data and all-IP, which can change the way networks are built and managed. 5G (or New Radio, NR) networks are designed to support multiple tiers, in which MEC servers can be placed between the core and the base station or NodeB (gNB). It should be understood that MEC can also be applied to 4G networks.

[0015] 5G can also leverage satellite communications to enhance or complement the coverage of 5G services. For example, by providing backhauling. Possible use cases are to provide service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for passengers on vehicles, or to ensure service availability for critical communications and future railway / maritime / aeronautical communications. Satellite communications can leverage geostationary Earth orbit (GEO) satellite systems, but also low Earth orbit (LEO) satellite systems, in particular mega-constellations (systems in which hundreds of (nano)satellites are deployed). Each satellite in a mega-constellation can cover several network entities of the supporting satellite that create ground cells. Ground cells can be created through ground relay nodes or by gNBs located on the ground or in satellites.

[0016] Embodiments can also be applicable to narrow band (NB) Internet of Things (IoT) systems, which can enable the use of cellular telecommunication bands to connect various devices and services. NB-IoT is a narrowband radio technology designed for the Internet of Things (IoT), and is one of the technologies standardized by the Third Generation Partnership Project (3GPP). Other 3GPP IoT technologies that are also suitable for implementing embodiments include Machine Type Communication (MTC) and eMTC (enhanced Machine Type Communication). NB-IoT focuses in particular on low cost, long battery life, and enabling a large number of connections. The NB-IoT technology is deployed “in-band” in spectrum allocated to Long Term Evolution (LTE) - using resource blocks within a normal LTE carrier, or in “guard-band” or “standalone” for deployments in dedicated spectrum.

[0017] Embodiments can also be applicable to device-to-device (D2D), machine-to-machine, peer-to-peer (P2P) communication. Embodiments can also be applicable to vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), infrastructure-to-vehicle (I2V), or generally to V2X or X2V communication.

[0018] Figure 1 An example of a communication system to which embodiments of the application can be applied is shown. The system can comprise a control node 110 providing one or more cells, such as cell 100, and a control node 112 providing one or more other cells, such as cell 102. Each cell can be, for example, a macrocell, microcell, femtocell or pico cell. In another view, a cell can define a coverage or service area of a respective access node. The control nodes 110, 112 can be evolved Node Bs (eNBs) as in LTE and LTE-A, ng-eNBs as in eLTE, gNBs of 5G, or any other apparatus capable of controlling radio communications and managing radio resources within a cell. The control nodes 110, 112 can be referred to as base stations, network nodes or access nodes.

[0019] The system can be a cellular communications system composed of a radio access network of access nodes, each controlling a respective cell or cells. The access node 110 can provide wireless access to other networks, such as the Internet, to user equipment (UE) 120 (one or more UEs). The wireless access can include downlink (DL) communication from the control node to the UE 120 and uplink (UL) communication from the UE 120 to the control node.

[0020] In addition, although not shown, one or more local area access nodes can be arranged such that the cells provided by the local area access nodes at least partially overlap with the cells of the access nodes 110 and / or 112. The local area access nodes can provide wireless access within a sub-cell. Examples of sub-cells can include microcells, picocells, and / or femtocells. Typically, the sub-cells provide hotspots within the macrocell. The operation of the local area access nodes can be controlled by an access node under whose control area the sub-cell is provided. Typically, the control node of the small cell can be similarly referred to as a base station, network node, or access node.

[0021] There can be one or more UEs 120, 122 in the system. The UEs 120, 122 can be served by one or more control nodes 110, 112. The UEs 120, 122 can communicate with each other, e.g., using a D2D communication interface established between them. The D2D communication can refer to, e.g., sidelink (SL) communication, such as NR sidelink communication.

[0022] The term "terminal device" or "UE" refers to any terminal device capable of wireless communication, more specifically cellular wireless communication. As examples without limitation, a terminal device can also be referred to as a communication device, a user equipment (UE), a subscriber station (SS), a portable subscriber station, a mobile station (MS), or an access terminal (AT). A terminal device can include, but is not limited to, a mobile telephone, a cellular telephone, a smart phone, a voice over Internet Protocol (VoIP) telephone, a wireless local loop (WLL) telephone, a tablet, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device, such as a digital camera, a gaming terminal device, a music storage and playback appliance, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a USB dongle, a smart device, a wireless customer-premise equipment (CPE), an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical appliance or application, such as a remote surgery appliance or application, an industrial appliance or application, such as an industrial robot or other wireless devices operating in an industrial and / or an automated processing chain context, a consumer electronics, a device operating on a business and / or a

[0023] In case of multiple access nodes in a communication network, the access nodes can be connected to each other over an interface. The LTE specification refers to such an interface as an X2 interface. For IEEE 802.11 networks, i.e. wireless local area networks, WLAN, WiFi, a similar interface can be provided between access points. The interface between LTE access points and 5G access points or between two 5G access points can be referred to as Xn. Other methods of communication between access nodes are also possible. The access nodes 110 and 112 can also be connected to a core network 116 of the cellular communication system via another interface. The LTE specification refers to the core network as the Evolved Packet Core (EPC) and the core network can comprise a Mobility Management Entity (MME) and a gateway node. The MME can handle mobility of terminal devices in tracking areas comprising multiple cells and handle signaling connections between terminal devices and the core network. The gateway node can handle data routing in the core network and to / from terminal devices. The 5G specification refers to the core network as the 5G Core (5GC) and among others the core network can comprise an Access and Mobility Management Function (AMF) and a User Plane Function / Gateway (UPF), just to name a few. The AMF can handle termination of Non-Access Stratum (NAS) signaling, NAS ciphering and integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management. The UPF node can support packet routing and forwarding, packet inspection and QoS handling, for example.

[0024] 6G networks are expected to employ flexible decentralized and / or distributed computing systems and architectures and ubiquitous computing, where local spectrum licensing, spectrum sharing, infrastructure sharing, and intelligent automated management are determined by mobile edge computing, artificial intelligence, short packet communication, and blockchain technologies. Key features of 6G will include intelligent management and control functions, programmability, integrated sensing and communication, reduction of energy occupancy, trusted infrastructure, scalability, and affordability. In addition to these, 6G targets new use cases that integrate positioning and sensing capabilities into the system definition to unify user experiences across the physical and digital worlds.

[0025] Figure 1One or more UEs 120, 122 of the cellular communication system can support sidelink positioning. In sidelink positioning, positioning is a positioning technology used, for example, in 5G NR communication networks. In sidellink positioning, signals transmitted over a sidelink (i.e., between UEs) are used to compute the location of a given UE. When a UE determines that sidelink positioning is needed, it can first determine which potential anchor UEs (i.e., UEs that can be used as reference points in the positioning computation) are within its range, and then select one or more of these anchor UEs to perform trilateration or other actions needed to determine the location. The location of the target UE can be determined at the target UE, at a location management function (LMF) (sometimes referred to as a location server or a sensing server), and / or at some other UE that supports the target UE or acts as an LMF. The location determination can be based at least on measurements of one or more positioning reference signals (PRS) communicated between the anchor UEs and the target UE.

[0026] For example, to enable an anchor UE to indicate whether its location is known, a sidelink positioning protocol (SLPP) metadata field can be included in a sidelink discovery message to indicate whether the location is known. For example, such an indication can be a flag or a binary indicator: “location known” or “location unknown”. Thus, a potential target UE can determine whether the location of an anchor UE is known, and thus whether it can be used to determine the location of the target UE (also referred to as the positioning of the target UE). The location of the target UE relative to the anchor UE can be computed based on measurements of one or more reference signals (PRS and / or SRS) transmitted between the anchor UE and the target UE. To compute the absolute location of the target UE, it can be needed to know the absolute location of the anchor UE (i.e., with multilateration relative to the anchor UE). Thus, the indication from the anchor UE can indicate whether the absolute location of the anchor UE is known. For example, if the absolute location of the anchor UE is known, the UE can be referred to as a “positioning UE”.

[0027] Some simple examples are shown with respect to how the location of the target UE 120 can be computed / determined. With reference to Figure 2 , according to a first example, the target UE 120 can measure PRS (i.e., SL PRS) transmitted by the anchor UE 122, 222 via the sidelink communication link 202, 204. According to a second example, the target UE 120 can transmit PRS (i.e., SL PRS) to the anchor UE 122, 222 via the sidelink communication link 202, 204. A combination of the first and second examples can be used.

[0028] The transmitted PRSs can be measured to obtain, for example, direction (e.g., angle of arrival (AOA)) and strength (e.g., received signal strength indicator (RSSI)) information. Based on the information and information about the location information on the anchor UE 122, 222, an absolute position of the target UE 120 can be determined. In one example, the absolute position of the target UE 120 can be determined at the target UE 120. In one example, the absolute position of the target UE 120 can be determined at the location management entity 250 (e.g., LMF or a UE acting as an LMF (e.g., referred to as a server UE)). In this case, the measurements of the PRSs can be shared with the location management entity 250. However, it has not been proposed how an (absolute position is known / absolute position is unknown) indication should be provided between UEs and how this indication should be utilized to determine the absolute position of the anchor UE at the entity that will determine the absolute position of the target UE. Therefore, a solution is proposed that enables providing absolute position information on the anchor UE.

[0029] Figure 3A and 3B A flow diagram is shown in accordance with some embodiments. Referring to Figure 3A , a method for an apparatus of a radio access network (RAN), such as a cellular communication network, is proposed. The apparatus can be or be comprised in a UE, such as Figure 1 and / or Figure 2 UE 120, 122, 222 of Figure 1. For simplicity, the apparatus performing the method of Figure 3A is referred to herein as UE 122. Thus, the apparatus can be capable of acting as an anchor UE for sidelink positioning. In some examples, the UE 122 can be referred to as a positioning UE (LUE). That is, the UE 122 can be an LUE if its absolute position is known to, for example, the UE 122 or the LME 250.

[0030] According to embodiments, Figure 3A the method comprises generating a SL discovery message indicating that absolute position information (indicative of an absolute position of the apparatus) is available (block 302), transmitting the SL discovery message to at least a terminal device (block 304), and indicating the absolute position information and / or a network node storing the absolute position information to the terminal device (block 306).

[0031] The SL discovery message can be transmitted to one or more terminal devices. For example, the SL discovery message can be broadcast by the UE 122 and other UEs can receive the broadcasted SL discovery message. In this example, the SL discovery message is transmitted to at least one UE (referred to above as a terminal device). The terminal device can be referred to hereinafter as a UE 120, which can be a target UE (tUE) that needs to be positioned via SL positioning (session-based or session-less SL positioning).

[0032] The solution herein proposes that the SL discovery message can be used to indicate that the UE 122 position is known (i.e. the position information is available and indicates that the absolute position of the UE 122 is known). For example, the indication can be a flag or bit indicator indicating that the position information is available. On the other hand, if the position information is not available, the UE 122 can send a SL discovery message indicating that the position information is not available or not send a SL discovery message at all. It can also be beneficial to also send a SL discovery message indicating that the position information is not available, since such UE can still enable performing relative positioning. However, the absolute position of the UE 122 (and possibly some other UEs) can be needed to perform absolute positioning of the target UE 120 (to improve the accuracy of the positioning). Furthermore, the solution proposes that the UE 122 indicates to the target UE 120 the absolute position information about the UE 122 or a network node storing the absolute position information about the UE 122. Thus, the target UE 120 can directly obtain the absolute position information or can request the position information from the indicated network node storing the absolute position information. Thus, the target UE 120 can obtain the absolute position information on the UE 122 which can then be used for absolute positioning of the target UE 120. As described with reference to Figure 2 the absolute position of the anchor UE can be needed to determine the absolute position of the target UE.

[0033] The indication of the absolute position information and / or the network node storing the absolute position information can be done in a number of ways. For example, the SL discovery message sent in block 304 can be used to convey such information. Other examples include sharing the information via radio resource control (RRC) signaling, via sidelink positioning protocol (SLPP) signaling, via LTE positioning protocol (LPP) signaling as ciphered information (using one or more ciphering keys) and / or as assistance data. The indicated absolute position information and / or the indication of the network node can include a validity indicator (e.g. a timer and / or a time stamp) to indicate the validity time of the indicated information. For example, the absolute position information can be indicated to be valid for a certain time. In another example, the absolute position information can be associated with a time stamp indicating the time of obtaining the absolute position of the UE 122. Thus, for example, the UE 120 can determine how long the information is valid based on the time stamp and some (pre-) configuration.

[0034] The absolute position information can be indicative of an absolute position of the UE associated with the absolute position information. For example, the absolute position information on the UE 122 can be indicative of an absolute position of the UE at least at a certain point in time. The accuracy of the absolute position can depend on the method used for positioning the UE 122 and / or the time elapsed after the positioning has been performed. The absolute position information can be indicative of the absolute position, e.g., as coordinates. For example, the coordinates can be two- or three-dimensional. For example, the coordinates can be indicative of latitude, longitude, and / or altitude.

[0035] Reference is made to Figure 4 A method for an apparatus of a wireless access network (RAN), such as a cellular communication network, is proposed. The apparatus can be or be comprised in a UE, such as the UE 120, 122, 222 of Figure 1 and / or Figure 2 For simplicity, the apparatus performing the method of Figure 4 is referred to herein as the UE 120. Thus, the apparatus can be capable of acting as a target UE for sidelink positioning. That is, the UE 120 can need to be positioned (or position itself) at a certain point.

[0036] According to embodiments, Figure 4 The method comprises receiving, from a terminal device (e.g., the UE 122), a SL discovery message indicating that absolute position information indicative of an absolute position of the terminal device (e.g., the UE 122) is available (block 312), obtaining the absolute position information or an indication of a network node storing the absolute position information from the terminal device (e.g., the UE 122) (block 314), and determining a position of the apparatus with the absolute position information and / or the indication of the network node storing the absolute position information (block 316).

[0037] The obtaining step 312 can correspond to the sending step 304 of Figure 3A That is, the SL discovery message sent (e.g., broadcast) can be received by the UE 120. Similarly, the step 314 can correspond to the step 306 of Figure 3A In block 316, the UE 120 can determine a position of the UE 120 with the absolute position information (e.g., as explained with reference to Figure 2 ), or it can request the indicated network node to provide the absolute position information in case of only indicating the network node.

[0038] One example of utilizing absolute position information is for the UE 120 to determine the absolute position of the UE 122 and further use this information in determining the absolute position of the UE 120 based on one or more reference signal measurements. Another example can be to provide the absolute position information to another entity, such as the LME 250 or another UE, for determining the absolute position of the UE 120. For example, if the UE 120 is a wrist device or similar device, it can provide the absolute position information to a mobile phone for determining the position of the UE 120.

[0039] Before going into further details, it is now highlighted that there can be at least two different ways of obtaining the absolute position information indicating the absolute position of the UE 122. A first option is for the UE 122 to directly indicate said information to the UE 120 (and possibly also to some other UE). The actual indication can be performed in a number of different ways as discussed below. A second option is for the UE 122 to indicate a network node storing the absolute position information. The indication of the network node can be performed in a number of different ways. A third option can be for both the absolute position information (which can be abbreviated as ALI) and the network node storing the absolute position information to be indicated to the UE 120.

[0040] The network node can be indicated, e.g., by indicating an identifier of the network node (e.g., a globally unique identifier). For example, the identifier can be sent from the UE 122 to the UE 120. In an embodiment, the network node is the UE 122; and thus the UE 122 can indicate itself as the network node storing the ALI. In one embodiment, the network node is an external network node. I.e., it can be a network node different from the UE 122. For example, the network node can be the LME 250 (e.g., an LMF, a location server, a sensing server, or a server UE). In case of a server UE indication, in some embodiments, the UE 122 itself is the server UE and thus can indicate itself as described above.

[0041] Instead of sending an identifier of the network node storing the ALI, the indication can be an implicit indication. For example, a default LMF (either at the core network or an LMF at a server UE) can be indicated. On the other hand, the indication can explicitly indicate the default LMF without necessarily using an identifier of the default LMF. The default LMF can refer to, e.g., a default or assumed LMF for the UE 120. Thus, if the default LMF is indicated, the UE 120 can request the ALI from the LMF associated with the UE 120 (e.g., the default LMF for the UE 120).

[0042] Let us then note that Figure 4which shows a signaling diagram in accordance with at least one embodiment. In block 400, one or more encryption keys (CKs) are assigned to UE 122 and UE 120 to enable encrypted communication for sidelink positioning. Thus, UE 122 and UE 120 can obtain one or more CKs. Similarly, if an external LME 250 is used in SL positioning, LME 250 can also obtain one or more CKs. For example, the distribution of CKs can function such that different entities involved in encrypted communication can share their respective CKs with other entities. By doing so, the CKs can be used to share encrypted information, as the information can be decrypted using the CKs obtained from the information sharing entities. Thus, for example, an indication of an ALI or a network node can be encrypted by UE 122 before sending. UE 120 can use at least one CK of UE 122 to decrypt the received information and obtain the indication of the ALI or the network node. However, other UEs or devices can not decrypt the information, as they can not have the correct CK, and thus the location of UE 122 can remain secret from the other UEs or devices. This can enhance the security of the location sharing. Similar logic can also apply to the case where a network node supplies an ALI to UE 120. That is, the ALI can be encrypted and thus can be decrypted by UE 120 using at least one CK of the network node (e.g., LMF).

[0043] Before going into details of sharing the ALI with UE 120, one example of how the ALI can be obtained on UE 122 can be shown in Figure 4 . That is, in block 404, UE 122 can start a positioning session that includes LME 250. The positioning session can be a Uu-based or SL-based positioning session in which an absolute position of UE 122 can be obtained. In another example, a non-RAN-specific positioning such as satellite positioning can be used to obtain the position of UE 122.

[0044] In the example of Figure 4 , LME 250 can obtain absolute position information about UE 122, for example, based on Uu or SL positioning of UE 122 (block 406). For example, the SL positioning can be based on a mobile terminated location request (MT-LR).

[0045] In step 408, the LME 250 can provide the UE 122 with absolute location information (i.e., ALI). Additionally, the LME 250 can request (i.e., explicitly request) the UE 122 to start advertising that the ALI is available. For example, the request can be sent with the ALI. For example, the request can be a flag or bit indicator (e.g., an indication state LUE) that requests the UE 122 to activate itself as a LUE (a located UE). For example, if the value of the indication state LUE is equal to 1, it can mean that the LME 250 requests the UE 122 to start advertising that the ALI is available.

[0046] In an embodiment, the UE 122 is configured to obtain, from a network node (e.g., the LME 250), absolute location information on the UE 122 and a request to indicate that the absolute location information is available through a broadcast SL discovery message. Thus, the UE 122 can start broadcasting a SL discovery message indicating that the location information is available.

[0047] In another example, the request to start advertising (i.e., broadcasting discovery messages) is sent separately.

[0048] In another example, the request to start advertising is implicit. That is, by sending the ALI to the UE 122, the LME 250 can implicitly request the UE 122 to start advertising.

[0049] In yet another example, the UE 122 can determine to start sending discovery messages based on the request from the LME 250 or based on receiving the ALI. In other words, as a LUE, the UE 122 can activate itself or activate based on receiving the ALI (block 410).

[0050] Alternatively, the UE 122 can obtain the absolute location information from another UE of the collective positioning group.

[0051] In block 412, the positioning session can end. However, the UE 122 can then be ready to provide the ALI or indicate to a network node that stores ALI of other UEs.

[0052] Figure 5A A signaling diagram is shown in accordance with at least one embodiment. Reference is made to Figure 5A In step 502, the UE 122 can send a SL discovery message indicating that the absolute location of the UE 122 is available. For example, the message can be received by the UE 120 (e.g., a target UE 120).

[0053] In an example embodiment, the SL discovery message includes a location status information element indicating that the absolute location of the UE 122 is available. The location status information element can be, for example, a flag or bit indicator. For example, the location status information element can be referred to as statusLUE, where a value of statusLUE equal to 1 can indicate that the absolute location of the UE 122 is available. The signaling of step 502 can be sent based at least on the absolute location information being available to the UE 122 or stored at a network node (e.g., at the LME 250), for example.

[0054] In an embodiment, the UE 122 is configured to determine whether absolute location information is available to the UE 122. Based on determining that absolute location information is available to the UE 122, the UE 122 can send the SL discovery message of step 502.

[0055] In an embodiment, the UE 122 is configured to determine whether absolute location information is stored at a network node. Based on determining that the network node stores absolute location information, the UE 122 can send the SL discovery message of step 502.

[0056] In general, the UE 122 can be configured to send the SL discovery message indicating that absolute location information is available based at least on the absolute location information being available to the UE 122 or stored at a network node.

[0057] Determining by the UE 122 that absolute location information is available to the UE 122 or stored at a network node (e.g., the LME 250) can be based on at least one of: the absolute location information being stored at the device; the absolute location information being received from the network node; the UE 122 obtaining an indication from the network node that the absolute location information is stored at the network node; or the UE 122 performing or having performed a positioning of the UE 122 with the network node (e.g., as explained with respect to Figure 4 FIG. 4).

[0058] Considering a first case, the UE 122 can determine that absolute location information is available to the UE 122 or stored at a network node based on storing the ALI at the UE 122. Thus, inevitably, the absolute location of the UE 122 is available because the ALI indicates the absolute location of the UE 122.

[0059] Considering a second case, the UE 122 can determine that absolute location information is available to the UE 122 or stored at a network node based on receiving the ALI from the LME 250. For example, the ALI can be received from the LME 250 in step 408 of Figure 4 FIG. 4.

[0060] Considering the third case, UE 122 can determine that absolute location information is available to UE 122 or stored at the network node based on receiving an indication from LME 250 that ALI is stored at LME 250.

[0061] The fourth case can be that UE 122 determines that absolute location information of UE 122 is available (i.e., stored) or at least available to LME 250 based on a positioning of UE 122 involving LME 250. For example, based on performing a positioning session as in steps 406-408 with LME 250, UE 122 can determine that LME 250 knows the absolute location of UE 122, even though the absolute location is not necessarily shared with UE 122 (as in step 408). Figure 4

[0062] UE 122 can use a combination of the different cases to determine that absolute location of UE 122 is available (i.e., ALI stored at UE 122 or at a network node).

[0063] Referring to Figure 5A , the validity of ALI can expire, as illustrated in FIG. 504. For example, ALI can be considered valid for a period of time, after which ALI can become invalid. An example of such a timer can be a TimeToLive counter or a maximum duration timer that can be reset after each UE 122 positioning event. Thus, for example, after a certain time has passed from obtaining ALI (e.g., expiration of a timer that was started when ALI was obtained), ALI can be determined to be invalid. Such a timer can be started and / or reset (i.e., started from a configured value) based on receiving ALI from LME 250, for example (e.g., as in step 408).

[0064] In another example, the validity of ALI can expire (i.e., ALI can become invalid, i.e., no longer valid or considered valid) based on a mobility event such as acceleration, timing advance change, handover, and / or a change in a reference signal such as reference signal received power (RSRP). For example, UE 122 can detect a mobility event and determine based thereon that ALI is no longer valid.

[0065] In another example, the validity of ALI can expire based on receiving a message or command from a network node (e.g., LME 250). For example, LME 250 can indicate that ALI is no longer valid.

[0066] ​Furthermore, the UE 122 can indicate to the LME 250 whether the ALI becomes invalid based on, for example, expiration of a timer or mobility event detection as discussed above. Such indication can be performed by the UE 122 sending a message to the LME indicating that the ALI is invalid. This can enable the LME 250 to start a new positioning session to locate the UE 122 so that it can continue to operate as an anchor UE, for example.

[0067] Based on the absolute location information being invalid or becoming invalid, the UE 122 can generate and transmit a discovery message indicating that the location information is not available (step 506). In another embodiment, the UE 122 can simply stop sending the message of step 502 without sending the message 506.

[0068] As discussed herein, the discovery message (e.g., of step 502) can be a SL discovery message broadcast by the UE 122. Thus, the message can be received by one or more UEs, such as by the UE 120. Thus, the UE 120 can determine whether the absolute location of the UE 122 is available.

[0069] Figure 5B Embodiments are shown in which the SL discovery message includes the absolute location information and / or an indication of a network node storing the absolute location information. Thus, the SL discovery message transmitted in step 512 can include, for example, a location status information element indicating that the absolute location of the UE 122 is available and in addition the ALI and / or an indication of a network node storing the ALI. Thus, the SL discovery message itself can be used to convey the location information (i.e., the ALI or the indication of a network node storing the ALI). This brings the benefit that additional signaling between the UE 122 and the UE 120 can not necessarily be required. However, the UE 120 can request an updated ALI from the UE 122 or an update of the ALI at a later stage (e.g., after a certain time period). Thus, the validity of the ALI can be maintained.

[0070] In embodiments, the location information is encrypted using one or more CKs.

[0071] For example, the location status information element can be a SLPP metafield (e.g., in the form of an elevated binary flag) indicating the UE 122 localization status. Also, the SLPP field can carry the UE 122 location information encrypted with a CK. In this way, other UEs (e.g., self-localization target UEs or server UEs) in possession of the CK can use the UE 122 as an anchor UE for absolute localization purposes. Once the validity of the LUE location expires (e.g., based on a fixed timer or under UE 122 mobility), the localization status can be set to reflect a non-LUE status, meaning availability for relative localization (e.g., ranging) only. See, e.g., Figure 5Aof step 506.

[0072] Furthermore, in some examples, providing the UE 120 with the ALI and the indication of the network node (via the discovery message or via some other signaling / message) can be beneficial as it can enable the UE 120 to quickly obtain the absolute position of the UE 122, but also enable the UE 120 to request the ALI from the indicated network node, e.g., after the validity of the initially provided ALI expires. That is, the ALI at the network node can have been updated based on a further or continued positioning session of the UE 122 including the indicated network node (e.g., LME 250).

[0073] In embodiments, the SL discovery message includes the absolute position information and / or the indication of the network node storing the absolute position information, but no location status information element. Thus, the ALI or the indication of the network node in the SL discovery message can implicitly indicate the location status of the UE 122 (i.e., that the UE 122 is positioned or that the absolute position of the UE 122 is available).

[0074] In embodiments, the SL discovery message, such as the SL discovery message in step 512, is transmitted based on (e.g., in response to) a SL discovery message received (i.e., transmitted by the UE 120) from the UE 120. For example, the SL discovery message received from the UE 120 can request an indication of the location status of the UE 122 (or any other UE receiving the message). Thus, the UE 122 can respond by transmitting the discovery message of step 512. For the sake of clarity, the SL discovery message transmitted by the UE 120 can be referred to herein as a SL discovery request. However, it can be a SL discovery message for requesting the location status of the UE 122.

[0075] In another embodiment, the SL discovery message, such as the SL discovery message in step 512, is transmitted without a request from the UE 120. For example, the SL discovery message can be transmitted periodically. For example, the periodic transmission can be started based on one or more criteria being met.

[0076] For example, the UE 122 can start transmitting the SL discovery message indicating that the absolute position information is available (with or without the location information as described in Figure 5B step 408 of FIG. 4) from a network node (e.g., LME 520) indicating a request for the absolute position information to be available; receiving a SL discovery request indicating whether the absolute position information is available (see, e.g., step 522 of FIG. 5); completing a positioning of the UE 122 (see, e.g., FIG. 6 showing the UE 122 being located in a cell 610 of a network node 620); and / or any other criteria. Figure 4 Figure 5C Figure 4 ​​); start acting as or determine to start acting as an anchor UE for absolute positioning; or determine that the UE 122 is or will be acting as an anchor UE for absolute positioning. Any one of the criteria described can be used as a trigger for starting to broadcast the SL discovery message indicating that absolute position is available, alone or in combination with any other of the criteria. Thus, for example, the UE 122 can be configured to start sending the SL discovery message based on satisfying both of the following conditions: receiving the request from the LME 250 and receiving the request from the UE 120. On the other hand, the UE 122 can be configured to start sending the SL discovery message based on satisfying only one of the criteria. In addition, and as mentioned above, for indicating that absolute position is available, the absolute position should be available directly from the UE 122 or from a network node storing the ALI.

[0077] In an embodiment, the UE 122 is configured to generate a location information message comprising the absolute position information and / or an indication of a network node storing the absolute position information; and send the location information message to the UE 120. The location information message can be separate from the SL discovery message. The location information message can be encrypted, e.g., using one or more CKs. This can mean, for example, that the absolute position information and / or the indication of the network node is encrypted.

[0078] In an embodiment, the UE 120 is configured to receive the location information message. If the content is encrypted, the UE 120 can decrypt the location information message to obtain the absolute position information and / or the indication of the network node.

[0079] In an embodiment, the UE 122 is configured to transmit the location information message based on receiving a location information request for the absolute position information from the UE 120. In an example, the location information message is sent in response to receiving the request. Thus, the UE 120 can be configured to generate a location information request for the absolute position information. The location information request can be generated and / or sent based on receiving a SL discovery message from the UE 122 indicating that absolute position information is available, for example, as in step 502 of Figure 5A The location information request can be encrypted (or encrypted), e.g., as shown in Figure 4 However, the main benefit of encryption can be to hide the location information (e.g., ALI) from harmful entities, and thus even if the location information is encrypted, other messaging can not be encrypted at all. However, this can depend on implementation.

[0080] Figure 5C A signaling diagram is shown in which location information is requested by the UE 122 and provided to the UE 120, according to at least one embodiment. Reference is made to Figure 5CAt step 522, UE 120 can use the SL discovery request to request that UE 122 (and possibly other UEs) indicate whether absolute location is available. UE 120 can generate the request prior to transmitting the SL discovery request.

[0081] In this example, absolute location is available for UE 122, so UE 122 can respond (e.g., begin transmitting) by transmitting a SL discovery message indicating that absolute location information is available (step 524). In this example, the SL discovery message can not include the ALI or an indication of the network node storing the ALI.

[0082] UE 120 can receive the discovery message transmitted at step 524, and based on receiving the SL discovery message, request absolute location information on UE 122 by transmitting a location information request to UE 122 (step 528). For example, the location information request can be generated and / or transmitted based on receiving the SL discovery message from UE 122 indicating that absolute location information is available (e.g., as described in step 502 of Figure 5A or step 524 of Figure 5C ).

[0083] UE 122 can receive the location information request, and based on the location information request, transmit a location information message including the ALI and / or an indication of the network node (e.g., an identifier of the network node) to UE 120 (step 530). Thus, UE 120 can obtain the ALI on UE 122, or at least can determine the network node from which the ALI can be requested.

[0084] In one embodiment, the location information request is a capability request message, such as a requestCapability message. Thus, the location information message can be a capability indication message, such as a provideCapability. Other delivery manners are possible, for example via an assistance data format and / or via RRC.

[0085] In embodiments, the SL discovery message indicating that the absolute position of the UE 122 is available (i.e., absolute location information (abbreviated as ALI) is available) comprises a validity indicator indicating a time period for which the absolute position is valid. For example, the SL discovery message can indicate that the absolute location information is valid for a certain time or time period. Or as mentioned above, the SL discovery message can simply comprise a timestamp indicating the time at which the absolute position was obtained. At this point, the timestamp can be understood as a validity indication. Based on such information, the UE 120 can determine whether to request the location information from the UE 122, e.g., as in step 528. Even expired location information can still be useful for retrospective positioning, e.g., as part of a continuous positioning tracking procedure. However, such decision can be left to implementation, as it can depend on the situation in which the UE 120 is.

[0086] In embodiments, Figure 5B and 5C may be understood to illustrate a case in which the ALI is stored at the UE 122 and thus can be provided to the UE 120 via the SL discovery message 512 or via the location information message 530 directly. This can be beneficial, e.g., in case at least one of the UEs 120, 122 is not connected to a cellular network (e.g., in a tunnel or some network interference) or more specifically to the LME 250 (e.g., LMF). Figure 6A and 6B Fig. 6 illustrates an example embodiment in which the ALI is stored at a network node (i.e., the LME 250) and thus an indication of the LME 250 can be provided by the UE 122 to the UE 120.

[0087] Referring first to Figure 6A In step 602, the UE 120 can send a SL discovery request for absolute location information to the UE 122.

[0088] In step 604, the UE 122 can respond by sending a SL discovery message indicating that the absolute position is available and further comprising an indication of the LME 250. As mentioned above, one example of such an indication is an identifier of the LME 250. Another example can be an indication of a default LME.

[0089] The UE 120 can obtain the indication of the LME storing the absolute location information based on receiving the SL discovery message (step 604).

[0090] In step 606, the UE 120 can request the absolute location information from the LME 250. The location information request of step 606 can be generated and / or sent based on the SL discovery message 604.

[0091] The LME 250 can receive the request and send a location information message to the UE 120 based on the request (step 608). The UE 120 can receive the location information message. As previously described, in at least some examples, the location information message can be encrypted. In the case that the location information message is sent by the LME 250, it includes the ALI (rather than an indication of the LME 250). Thus, in step 608, the LME 250 can send the ALI on the UE 122 to the UE 120.

[0092] Reference is then made to Figure 6B , the discovery request of step 612 can correspond to the discovery request of step 602 of Figure 6A . However, instead of indicating the LME in the discovery message (or discovery response) of step 614, the discovery message can only indicate that absolute location is available. Thus, the UE 120 can transmit a location information request to the UE 122 in step 616 to request the ALI on the UE 122.

[0093] When the ALI is stored at the LME 250 rather than at the UE 122, the UE can respond by sending a location information message indicating the LME 250 (step 618). Thus, the UE 120 can determine the network node from which the ALI can be requested (i.e., the LME 250 in the example). Thus, step 622 can correspond to step 606 of Figure 6A , and step 624 can correspond to step 608 of Figure 6A .

[0094] Figure 6C Another signaling diagram is shown in accordance with at least one embodiment. Reference is made to Figure 6C , in step 632, the LME 250 can indicate to the UE 122 to stop providing absolute location information. This can mean that the UE 122 deactivates its status as a LUE (step 634). Thus, for example, the UE 122 can stop sending SL discovery messages indicating that absolute location is available and / or start sending SL discovery messages indicating that absolute location information is not available.

[0095] In general, if absolute location is not available or invalid, the UE 122 can be caused to generate a SL discovery message indicating that absolute location information is not available; and send said another SL discovery message based on the absolute location information not being available or invalid. For example, the UE 122 can determine that absolute location information is no longer valid or no longer available based on a timer expiring or a message received from the LME 250 (e.g., step 632); and send a SL discovery message indicating that absolute location information is not available based on the determination. For example, the SL discovery message can be received by one or more UEs, such as by the UE 120.

[0096] exist Figure 6C In the example, another UE 690 requests location information about UE 122 from LME 250 (step 636). However, since UE 122 has been deactivated and is no longer an LUE, LME 250 can provide information about other anchor UEs (candidates) of UE 690. Therefore, UE 690 can request absolute location information about other anchor UE candidates.

[0097] Therefore, for example, once LUE 122 is no longer needed as an anchor (e.g., all absolute positioning sessions in the area end), LME 250 can explicitly instruct the LUE to stop advertising the LUE state (step 632). If any other UE (e.g., UE 690) simultaneously requests information about the location of LUE 122, the request can be rejected or a "null" response can be provided to indicate the LUE state. In other embodiments, alternative anchor LUEs with known location states can be provided to the target UE 690 to assist in its positioning.

[0098] Figure 7 At least one embodiment is shown. (Reference) Figure 7 The actions of UE 122 can be summarized by sending an SL discovery message indicating whether the absolute location is available.

[0099] In step 702, UE 122 may determine whether the absolute location of UE 122 is known and valid. If so, UE 122 may advertise itself as LUE (i.e., the located UE) by sending, for example, an SL discovery message indicating that the absolute location is available (box 704).

[0100] If not true, then UE 122 can determine (step 712) whether the absolute location of UE 122 is known by another network node and whether the absolute location is valid. If yes (i.e., a valid absolute location is known), then the process can continue to box 704.

[0101] If not true, UE 122 can stop advertising itself as a located UE, preventing itself from advertising itself as a located UE or as an unlocated UE. This means that UE 122 can be used for relative positioning, but not for absolute positioning of UE 120 or some other target UE (box 714).

[0102] For example, the process can continue to box 702 again, and therefore can be repeated.

[0103] For example, UE 120 (although not in Figure 7 (As shown in the image) can receive an SL discovery message indicating that absolute location information is unavailable, and therefore require different UEs to support their positioning in the future.

[0104] The embodiment shown in Figure 8 provides an apparatus 10 comprising a control circuit (CTRL) 12, such as at least one processor, and at least one memory 14 storing instructions (INSTRUCT.) that, when executed by the at least one processor, cause the apparatus to perform at least any of the processes described above. In an example, the at least one memory and the instructions are configured to, with the at least one processor, cause the apparatus to perform at least any of the processes described above. The memory can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The memory can comprise a database for storing data.

[0105] In an embodiment, the apparatus 10 comprises a terminal device of a communication system, e.g., a user terminal (UT), a computer (PC), a laptop, a tablet computer, a cellular phone, a mobile phone, a communicator, a smartphone, a palmtop computer, a mobile transportation device (e.g., a car), a household electric appliance, or any other communication apparatus, generally referred to as UE in the specification. Alternatively, the apparatus is comprised in such a terminal device. Further, the apparatus can be or comprise a module (to be attached to a UE) providing connectivity, such as a plug-in unit, a “USB dongle”, or any other type of unit. The unit can be installed inside the UE or attached to the UE with a connector or even wirelessly.

[0106] In an embodiment, the apparatus 10 is or is comprised in a UE 122. The apparatus can be caused to perform some of the functions of the processes described above, such as steps 302, 304, and 306 of Figure 3A .

[0107] The apparatus 10 can further comprise a wireless interface (TRX) 16 comprising hardware and / or software for implementing a communication connection according to one or more communication protocols. For example, the TRX can provide the apparatus with communication capabilities to access a wireless access network. For example, the TRX can enable SL communication.

[0108] The apparatus can further comprise a user interface 18 comprising, e.g., at least one keypad, a microphone, a touch display, a display, a loudspeaker, etc. The user interface can be used for controlling the apparatus by a user.

[0109] In an embodiment, the control circuit 12 comprises a generation circuit 20 for performing at least step 302 of Figure 3A ; a transmission circuit 22 for performing at least step 304 of Figure 3A ; and an indication circuit 24 for performing at least step 306 of Figure 3A .

[0110] AsFigure 9 The illustrated embodiment provides an apparatus 50 comprising a control circuit (CTRL) 52, such as at least one processor, and at least one memory 54 storing instructions (INSTRUCT.) that, when executed by the at least one processor, cause the apparatus to perform at least any of the above processes. In an example, the at least one memory and the instructions, with the at least one processor, are configured to cause the apparatus to perform at least any of the above processes. The memory can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The memory can comprise a database for storing data.

[0111] In an embodiment, the apparatus 50 comprises a terminal device of a communication system, e.g., a user terminal (UT), a computer (PC), a laptop, a tablet computer, a cellular phone, a mobile phone, a communicator, a smartphone, a palmtop computer, a mobile transportation device (e.g., a car), a home appliance, or any other communication apparatus, generally referred to as UE in the specification. Alternatively, the apparatus is comprised in such a terminal device. Further, the apparatus can be or comprise a module (to be attached to a UE) providing connectivity, such as a plug-in unit, a “USB dongle”, or any other type of unit. The unit can be installed inside the UE or attached to the UE with a connector or even wirelessly.

[0112] In an embodiment, the apparatus 50 is or is comprised in a UE 120. The apparatus can be caused to perform some functions of the above processes, such as Figure 3B steps 312, 314, and 316 of the process of FIG. 3.

[0113] The apparatus 50 can further comprise a radio interface (TRX) 56 comprising hardware and / or software for realizing communication connectivity according to one or more communication protocols. For example, the TRX can provide the apparatus with communication capabilities to access a wireless access network. For example, the TRX can enable SL communication.

[0114] The apparatus 50 can further comprise a user interface 58 comprising, e.g., at least one keypad, a microphone, a touch display, a display, a loudspeaker, etc. The user interface can be used for controlling the apparatus by a user.

[0115] In an embodiment, the control circuit 52 comprises a receiving circuit 60 for performing at least step 312 of the process of FIG. 3; an obtaining circuit 62 for performing at least step 314 of the process of FIG. 3; and a utilizing circuit 64 for performing at least step 316 of the process of FIG. 3. Figure 3B Figure 3B Figure 3B

[0116] ​​​According to an aspect, there is provided an apparatus comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform: obtaining absolute position information indicative of an absolute position of a first terminal device (e.g., UE 122); and requesting, based on a request or based on a further request via a second terminal device (e.g., UE 120), the first terminal device to send a SL discovery message indicating that the absolute position information is available. For example, the apparatus can be or be comprised in the LME 250, such as a LMF or a server UE.

[0117] In addition, the apparatus can be configured to provide the absolute position information to the first terminal device as described above (e.g., in step 408).

[0118] In addition, the apparatus can be configured to provide the absolute position information to the second terminal device based on (e.g., in accordance with) the request from the second terminal device (e.g., as in steps 606 / 608 and / or 622 / 624).

[0119] In embodiments, an apparatus performing at least some of the described embodiments comprises at least one processor and at least one memory including instructions that, when executed by the at least one processor, cause the apparatus to perform functions according to any of the described embodiments. According to an aspect, the instructions, when executed by the at least one processor, cause the apparatus to perform functions according to any of the described embodiments. According to another embodiment, an apparatus performing at least some of the described embodiments comprises at least one processor and at least one memory including instructions, wherein the at least one processor and the instructions perform at least some of the functions according to any of the described embodiments. Thus, the at least one processor, the memory and the instructions form a processing means for performing at least some of the described embodiments. According to yet another embodiment, an apparatus performing at least some of the described embodiments comprises a circuitry comprising at least one processor and at least one memory including instructions. When activated, the circuitry causes the apparatus to perform at least some of the functions according to any of the described embodiments.

[0120] As used in this application, the term "circuitry" refers to all of the following: (a) hardware-only circuitry such as only analog and / or digital circuitry, including only analog and / or digital circuitry that is solely hardware, (b) combinations of circuits and software (and / or firmware), such as (as applicable): (i) a combination of processor(s) or (ii) portions of processor(s) / software including digital signal processors, software, and memory that work together to cause an apparatus to perform various functions, and (c) circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present. This definition of "circuitry" applies to all uses of this term in this application. As a further example, as used in this application, the term "circuitry" would also cover an implementation that includes both a processor (or multiple processors) and memory that work together to cause an apparatus to perform various functions described herein. This definition of "circuitry" would also cover, for example and if applicable, baseband integrated circuitry or application-specific integrated circuitry for a mobile phone or a similar integrated circuitry in a server, cellular network device, or another network device.

[0121] In an embodiment, at least some of the processes described can be performed by a device that includes a corresponding means for performing at least some of the processes described. Some example means for performing processes can include at least one of the following: a detector, a processor (including dual-core and multi-core processors), a digital signal processor, a controller, a receiver, a transmitter, an encoder, a decoder, a memory, a RAM, a ROM, software, firmware, a display, a user interface, display circuitry, user interface circuitry, user interface software, display software, circuitry, an antenna, antenna circuitry, and circuitry.

[0122] The term non-transitory, as used herein, is a limitation of the medium itself (i.e., tangible and not a signal), and not a limitation on the persistence of the data stored thereon (e.g., RAM vs. ROM).

[0123] As used herein, the term "apparatus" shall be interpreted as singular, i.e., referring to a single element, or plural, i.e., referring to a combination of single elements. Thus, the term "apparatus for [performing A, B, C]" shall be interpreted to cover a device in which there is only one apparatus for performing A, B, and C, or in which there are separate apparatuses for performing A, B, and C, or a device in which the apparatuses for performing A, B, C are partially or completely overlapping.

[0124] The techniques and methods described herein can be implemented by various means. For example, these techniques can be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or combinations thereof. For a hardware implementation, the apparatuses of embodiments can be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. For firmware or software, the implementation can be carried out through modules of at least one chipset (e.g., processes, functions, etc.) that perform the functions described herein. The software codes can be stored in memory units and executed by processors. The memory unit can be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor via various means as is known in the art. Further, the components of the systems described herein can be rearranged and / or complemented by additional components in order to facilitate the achievements of the various aspects, etc., described with respect thereto, and they are not limited to the precise configurations set forth in the given figures, as will be appreciated by one skilled in the art.

[0125] Embodiments described can also be carried out in the form of a computer process defined by a computer program or portions thereof. Embodiments of the described methods can be carried out by execution of at least one part of a computer program comprising corresponding instructions. The computer program can be in source code form, object code form, or in some intermediate form, and it can be stored in some sort of carrier, which can be any entity or device capable of carrying the program. For example, the computer program can be stored on a computer program distribution package, which is a computer- or processor-readable medium. The computer program medium can be, for example but not limited to, a record medium, computer memory, read-only memory, electrical carrier signal, telecommunications signal, and software distribution package. The computer program medium can be non-transitory. Coding the software for execution on a computer or processor is well within the scope of one of ordinary skill in the art.

[0126] Embodiments: Example 1: An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform: generating a sidelink, SL, discovery message, the SL discovery message indicating that absolute position information is available, the absolute position information indicating an absolute position of the apparatus; transmitting the SL discovery message to at least a terminal device; and indicating to the terminal device at least one of: the absolute position information or a network node storing the absolute position information.

[0127] Example 2: The apparatus of Example 1, wherein the SL discovery message comprises at least one of: absolute position information or an indication of a network node storing the absolute position information.

[0128] Example 3: The apparatus of Example 1 or 2, wherein the SL discovery message comprises a location status information element indicating that absolute position information of the apparatus is available.

[0129] Example 4: The apparatus of any of Examples 1-3, caused to perform: generating a location information message comprising at least one of: absolute position information or an indication of a network node storing the absolute position information; and transmitting the location information message to a terminal device.

[0130] Example 5: The apparatus of Example 4, caused to perform: receiving a location information request for absolute position information, wherein generating the location information message is based on receiving the location information request.

[0131] Example 6: The apparatus of any of Examples 1-5, caused to perform: receiving a SL discovery request indicating whether absolute position information is available, wherein transmitting the SL discovery message indicating that absolute position information is available is based on receiving the SL discovery request.

[0132] Example 7: The apparatus of any of Examples 1-6, wherein the apparatus is caused to transmit the SL discovery message indicating that absolute position information is available based at least on the absolute position information being available to the apparatus or stored at the network node.

[0133] Example 8: The apparatus of Example 7, caused to perform: determining that absolute position information is available to the apparatus or stored at the network node based on at least one of: the absolute position information being stored at the apparatus; the absolute position information being received from the network node; obtaining an indication from the network node that the absolute position information is stored at the network node; or the apparatus performing or having performed a positioning of the apparatus with the network node.

[0134] Example 9: The apparatus of any of Examples 1-8, wherein the apparatus is caused to start transmitting the SL discovery message indicating that absolute position information is available based on at least one of: obtaining a request from the network node to indicate that absolute position information is available; receiving a SL discovery request indicating whether absolute position information is available; a positioning of the apparatus being completed; starting to act as or determining to start acting as an anchor UE for absolute positioning; or determining that the apparatus is or will be acting as an anchor UE for absolute positioning.

[0135] Example 10: The apparatus of any of Examples 1-9, caused to perform: obtaining absolute position information on the apparatus from the network node and a request to indicate by broadcasting the SL discovery message that the absolute position information is available.

[0136] Example 11 : The apparatus of any of examples 1 to 10, wherein the SL discovery message further indicates that the absolute position information is valid for a certain time.

[0137] Example 12: The apparatus of any of examples 1 to 11, caused to perform: generating another SL discovery message indicating that the absolute position information is not available; and based on the absolute position information being not available or being invalid, sending at least the other SL discovery message to the terminal device.

[0138] Example 13: The apparatus of example 12, caused to perform: determining, based on expiration of a timer or a message received from a network node, that the absolute position information is no longer valid; and based on the determination, sending at least the other SL discovery message to the terminal device.

[0139] Example 14: An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform: receiving, from a terminal device, a sidelink, SL, discovery message, the SL discovery message indicating that absolute position information is available, the absolute position information indicating an absolute position of the terminal device; obtaining, from the terminal device, at least one of: the absolute position information or an indication of a network node storing the absolute position information; and determining a position of the apparatus using at least one of: the absolute position information or the indication of the network node storing the absolute position information.

[0140] Example 15: The apparatus of example 14, wherein the SL discovery message comprises at least one of: the absolute position information or the indication of the network node storing the absolute position information.

[0141] Example 16: The apparatus of example 14 or 15, wherein the SL discovery message comprises a position status information element indicating that the absolute position of the terminal device is available.

[0142] Example 17: The apparatus of any of examples 14 to 16, caused to perform: receiving, from the terminal device, a position information message, the position information message comprising at least one of: the absolute position information or the indication of the network node storing the absolute position information.

[0143] Example 18: The apparatus of any of examples 14 to 17, caused to perform: generating, based on receiving the SL discovery message indicating that the absolute position information is available, a position information request for the absolute position information; and sending the position information request to the terminal device.

[0144] Example 19: The apparatus of any of examples 14 to 18, caused to perform: generating a SL discovery request for indicating whether the absolute position information is available; and sending at least the generated SL discovery request to the terminal device.

[0145] Example 20: The apparatus of any one of examples 14 to 19, caused to perform: obtaining, from the terminal device, an indication of a network node storing the absolute position information; requesting the absolute position information from the network node; and receiving the absolute position information from the network node.

[0146] Example 21 : The apparatus of any one of examples 14 to 20, wherein the received SL discovery message further indicates that the absolute position information is valid for a certain time.

[0147] Example 22: The apparatus of any one of examples 14 to 21, caused to perform: receiving, from the terminal device, a further SL discovery message indicating that the absolute position information is not available.

[0148] Example 23: An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform: obtaining absolute position information indicating an absolute position of a first terminal device; and requesting, based on a request or based on a further request via a second terminal device, the first terminal device to send a SL discovery message indicating that the absolute position information is available.

[0149] Example 24: A method comprising: generating, by an apparatus, a sidelink, SL, discovery message, the SL discovery message indicating that absolute position information is available, the absolute position information indicating an absolute position of the apparatus; sending the SL discovery message to at least a terminal device; and indicating, to the terminal device, at least one of: the absolute position information or a network node storing the absolute position information.

[0150] Example 25: A method comprising: receiving, by an apparatus from a terminal device, a sidelink, SL, discovery message, the SL discovery message indicating that absolute position information is available, the absolute position information indicating an absolute position of the terminal device; obtaining, from the terminal device, at least one of: the absolute position information or an indication of a network node storing the absolute position information; and determining a position of the apparatus utilizing at least one of: the absolute position information or the indication of the network node storing the absolute position information.

[0151] Example 26: A method comprising: obtaining, by an apparatus, absolute position information indicating an absolute position of a first terminal device; and requesting, based on a request or based on a further request via a second terminal device, the first terminal device to send a SL discovery message indicating that the absolute position information is available.

[0152] Example 27: A computer program product comprising program instructions to perform the method of any one of examples 24 to 26 when loaded into an apparatus.

[0153] Although the present application has been described above with reference to the example according to the accompanying drawings, it is apparent that the application is not limited to that, but can be modified in several ways within the scope of the attached claims. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, the embodiment. It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. Further, it will be apparent that the described embodiments are but non-limiting examples and that many details can be modified in sub-embodiments without departing from the scope of the application.

Claims

1. An apparatus comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the device to perform at least the following: Generate a sidelink SL discovery message, the SL discovery message indicating that absolute location information is available, the absolute location information indicating the absolute location of the device; At least the SL discovery message is sent to the terminal device; and Instruct the terminal device to at least one of the following: the absolute location information or the network node storing the absolute location information.

2. The apparatus of claim 1, wherein the SL discovery message includes at least one of the following: the absolute location information or an indication of the network node storing the absolute location information.

3. The apparatus of claim 1 or 2, wherein the SL discovery message includes a location status information element indicating that the absolute location of the apparatus is available.

4. The apparatus according to any one of the preceding claims is caused to perform: Generate a location information message, the location information message including at least one of the following: the absolute location information or the indication of the network node storing the absolute location information; and The location information message is sent to the terminal device.

5. The apparatus according to claim 4, wherein the following is performed: Receive a location information request for the absolute location information; The location information message is generated based on receiving the location information request.

6. The apparatus according to any one of the preceding claims is caused to perform: Receive an SL discovery request indicating whether the absolute location information is available. The SL discovery message indicating that the absolute location information is available is sent based on receiving the SL discovery request.

7. The apparatus according to any one of the preceding claims, wherein the apparatus is configured to: send an SL discovery message indicating that the absolute location information is available, at least based on the fact that the absolute location information is available to the apparatus or is stored at the network node.

8. The apparatus according to claim 7 is made to perform: The absolute location information is determined to be available to the device or stored at the network node based on at least one of the following: The absolute position information is stored in the device; The absolute location information is received from the network node; The absolute location information obtained from the network node is an indication that it is stored at the network node; or The device is performing or has performed the positioning of the device with the network node.

9. The apparatus according to any one of the preceding claims, wherein the apparatus is configured to initiate the transmission of the SL discovery message indicating that the absolute location information is available based on at least one of the following: Obtain a request from the network node indicating that the absolute location information is available; Receive an SL discovery request indicating whether the absolute location information is available; The positioning of the device has been completed; Begin to act as, or determine to begin acting as, the anchor UE for absolute positioning; or Determine that the device is currently or will be used as an anchor UE for absolute positioning.

10. The apparatus according to any one of the preceding claims is caused to perform: Obtain the absolute location information on the device from the network node, and request to indicate that the absolute location information is available by broadcasting the SL discovery message.

11. The apparatus according to any one of the preceding claims, wherein the SL discovery message further indicates that the absolute location information is valid for a specific time period.

12. The apparatus according to any one of the preceding claims is caused to perform: Generate another SL discovery message indicating that the absolute location information is unavailable; and If the absolute location information is unavailable or invalid, at least the other SL discovery message shall be sent to the terminal device.

13. The apparatus of claim 12, wherein the following is performed: Based on the expiration of the timer or a message received from the network node, it is determined that the absolute location information is no longer valid; and Based on the determination, at least the other SL discovery message is sent to the terminal device.

14. An apparatus comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the device to perform at least the following: The terminal device receives a sidelink SL discovery message, the SL discovery message indicating that absolute location information is available, and the absolute location information indicating the absolute location of the terminal device. Obtain at least one of the following from the terminal device: the absolute location information or an indication from the network node storing the absolute location information; as well as The location of the device is determined using at least one of the following: the absolute location information or the indication of the network node storing the absolute location information.

15. The apparatus of claim 14, wherein the SL discovery message includes at least one of the following: the absolute location information or the indication of the network node storing the absolute location information.

16. The apparatus of claim 14 or 15, wherein the SL discovery message includes a location status information element indicating that the absolute location of the terminal device is available.

17. The apparatus according to any one of claims 14 to 16, wherein the following is performed: The terminal device receives a location information message, the location information message including at least one of the following: the absolute location information or the indication of the network node storing the absolute location information.

18. The apparatus according to any one of claims 14 to 17, wherein the following is performed: Based on receiving the SL discovery message indicating that the absolute location information is available, a location information request is generated for the absolute location information; and Send the location information request to the terminal device.

19. The apparatus according to any one of claims 14 to 18, wherein the following is performed: Generate an SL discovery request to indicate whether absolute location information is available; and The generated SL discovery request is sent to the terminal device at least once.

20. The apparatus according to any one of claims 14 to 19, wherein the following is performed: The instruction from the network node storing the absolute location information is obtained from the terminal device; Request the absolute location information from the network node; and Receive the absolute location information from the network node.

21. The apparatus according to any one of claims 14 to 20, wherein the received SL discovery message further indicates that the absolute location information is valid for a specific time period.

22. The apparatus according to any one of claims 14 to 21 is made to perform: The terminal device receives another SL discovery message indicating that the absolute location information is unavailable.

23. An apparatus comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the device to perform at least the following: Obtain absolute position information indicating the absolute position of the first terminal device; and Based on a request or another request via a second terminal device, the first terminal device is requested to send an SL discovery message indicating that the absolute location information is available.

24. A method comprising: The device generates a sidelink SL discovery message, which indicates that the absolute location information is available and that the absolute location information indicates the absolute location of the device. At least the SL discovery message is sent to the terminal device; and Instruct the terminal device to at least one of the following: the absolute location information or the network node storing the absolute location information.

25. A method comprising: The device receives a sidelink SL discovery message from the terminal device, the SL discovery message indicating that absolute location information is available, and the absolute location information indicating the absolute location of the terminal device; Obtain at least one of the following from the terminal device: the absolute location information or an indication from the network node storing the absolute location information; as well as The location of the device is determined using at least one of the following: the absolute location information or the indication of the network node storing the absolute location information.

26. A method comprising: Obtain absolute position information indicating the absolute position of the first terminal device; as well as Based on a request or another request via a second terminal device, the first terminal device is requested to send an SL discovery message indicating that the absolute location information is available.

27. A computer program product comprising program instructions that, when loaded into a device, perform the method according to any one of claims 24 to 26.

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