WO2024027905A1

WO2024027905A1 - Positioning reference unit activation

Info

Publication number: WO2024027905A1
Application number: PCT/EP2022/071662
Authority: WO
Inventors: Taylan SAHIN; Stepan Kucera; Diomidis Michalopoulos
Original assignee: Nokia Technologies Oy
Priority date: 2022-08-02
Filing date: 2022-08-02
Publication date: 2024-02-08

Abstract

Disclosed is a method comprising receiving an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; transmitting, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and based on accepting the activation request, performing at least one of the following: transmit an uplink reference signal to one or more transmission and reception points, measure a downlink reference signal received from the one or more transmission and reception points, transmit a sidelink reference signal to the user device, or measure a sidelink reference signal received from the user device.

Description

POSITIONING REFERENCE UNIT ACTIVATION

FIELD

The following example embodiments relate to wireless communication and to positioning.

BACKGROUND

Positioning technologies may be used to estimate a physical location of a device. It is desirable to improve the positioning accuracy in order to estimate the location of the device more accurately.

BRIEF DESCRIPTION

The scope of protection sought for various example embodiments is set out by the independent claims. The example embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments.

According to an aspect, there is provided an apparatus comprising at least one processor, and at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to: receive an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; transmit, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and based on accepting the activation request, perform at least one of the following: transmit an uplink reference signal to one or more transmission and reception points, measure a downlink reference signal received from the one or more transmission and reception points, transmit a sidelink reference signal to the user device, or measure a sidelink reference signal received from the user device.

According to another aspect, there is provided an apparatus comprising: means for receiving an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; means for transmitting, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and means for performing, based on accepting the activation request, at least one of the following: transmitting an uplink reference signal to one or more transmission and reception points, measuring a downlink reference signal received from the one or more transmission and reception points, transmitting a sidelink reference signal to the user device, or measuring a sidelink reference signal received from the user device.

According to another aspect, there is provided a method comprising: receiving an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; transmitting, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and based on accepting the activation request, performing at least one of the following: transmit an uplink reference signal to one or more transmission and reception points, measure a downlink reference signal received from the one or more transmission and reception points, transmit a sidelink reference signal to the user device, or measure a sidelink reference signal received from the user device.

According to another aspect, there is provided a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; transmitting, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and based on accepting the activation request, performing at least one of the following: transmit an uplink reference signal to one or more transmission and reception points, measure a downlink reference signal received from the one or more transmission and reception points, transmit a sidelink reference signal to the user device, or measure a sidelink reference signal received from the user device. According to another aspect, there is provided a computer readable medium comprising program instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; transmitting, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and based on accepting the activation request, performing at least one of the following: transmit an uplink reference signal to one or more transmission and reception points, measure a downlink reference signal received from the one or more transmission and reception points, transmit a sidelink reference signal to the user device.

According to another aspect, there is provided a non-transitory computer readable medium comprising program instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; transmitting, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and based on accepting the activation request, performing at least one of the following: transmit an uplink reference signal to one or more transmission and reception points, measure a downlink reference signal received from the one or more transmission and reception points, transmit a sidelink reference signal to the user device.

According to another aspect, there is provided an apparatus comprising at least one processor, and at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to: transmit an activation request to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the apparatus; receive, from the one or more positioning reference units, a response to the activation request, wherein the response indicates an acceptance of the activation request; and transmit, to a network element, based on the response, a message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

According to another aspect, there is provided an apparatus comprising: means for transmitting an activation request to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the apparatus; means for receiving, from the one or more positioning reference units, a response to the activation request, wherein the response indicates an acceptance of the activation request; and means for transmitting, to a network element, based on the response, a message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

According to another aspect, there is provided a method comprising: transmitting, by a user device, an activation request to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the user device; receiving, by the user device, from the one or more positioning reference units, a response to the activation request, wherein the response indicates an acceptance of the activation request; and transmitting, by the user device, to a network element, based on the response, a message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

According to another aspect, there is provided a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: transmitting an activation request to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the apparatus; receiving, from the one or more positioning reference units, a response to the activation request, wherein the response indicates an acceptance of the activation request; and transmitting, to a network element, based on the response, a message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

According to another aspect, there is provided a computer readable medium comprising program instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: transmitting an activation request to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the apparatus; receiving, from the one or more positioning reference units, a response to the activation request, wherein the response indicates an acceptance of the activation request; and transmitting, to a network element, based on the response, a message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

According to another aspect, there is provided a non-transitory computer readable medium comprising program instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: transmitting an activation request to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the apparatus; receiving, from the one or more positioning reference units, a response to the activation request, wherein the response indicates an acceptance of the activation request; and transmitting, to a network element, based on the response, a message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

According to another aspect, there is provided an apparatus comprising at least one processor, and at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to: receive, from a user device or from one or more positioning reference units, a message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device; and based on receiving the message, obtain measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.

According to another aspect, there is provided an apparatus comprising: means for receiving, from a user device or from one or more positioning reference units, a message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device; and means for obtaining, based on receiving the message, measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.

According to another aspect, there is provided a method comprising: receiving, from a user device or from one or more positioning reference units, a message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device; and based on receiving the message, obtaining measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.

According to another aspect, there is provided a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving, from a user device or from one or more positioning reference units, a message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device; and based on receiving the message, obtaining measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.

According to another aspect, there is provided a computer readable medium comprising program instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving, from a user device or from one or more positioning reference units, a message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device; and based on receiving the message, obtaining measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.

According to another aspect, there is provided a non-transitory computer readable medium comprising program instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving, from a user device or from one or more positioning reference units, a message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device; and based on receiving the message, obtaining measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.

LIST OF DRAWINGS

In the following, various example embodiments will be described in greater detail with reference to the accompanying drawings, in which

FIG. 1 illustrates an example of a cellular communication network; FIG. 2 illustrates an example of a positioning scenario;

FIG. 3 illustrates a signaling diagram according to an example embodiment;

FIG. 4 illustrates a signaling diagram according to an example embodiment; FIG. 5 illustrates a signaling diagram according to an example embodiment; FIG. 6 illustrates a signaling diagram according to an example embodiment; FIG. 7 illustrates a signaling diagram according to an example embodiment; FIG. 8 illustrates a signaling diagram according to an example embodiment; FIG. 9 illustrates a flow chart according to an example embodiment;

FIG. 10 illustrates a flow chart according to an example embodiment;

FIG. 11 illustrates a flow chart according to an example embodiment;

FIG. 12 illustrates an example of an apparatus; and

FIG. 13 illustrates an example of an apparatus.

DETAILED DESCRIPTION

The following embodiments are exemplifying. Although the specification may refer to “an”, “one”, or “some” embodiment(s) in several locations of the text, this does not necessarily mean that each reference is made to the same embodiment(s), or that a particular feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.

In the following, different example embodiments will be described using, as an example of an access architecture to which the example embodiments may be applied, a radio access architecture based on long term evolution advanced (LTE Advanced, LTE-A), new radio (NR, 5G), beyond 5G, or sixth generation (6G) without restricting the example embodiments to such an architecture, however. It is obvious for a person skilled in the art that the example embodiments may also be applied to other kinds of communications networks having suitable means by adjusting parameters and procedures appropriately. Some examples of other options for suitable systems may be the universal mobile telecommunications system (UMTS) radio access network (UTRAN or E-UTRAN), long term evolution (LTE, substantially the same as E- UTRA), wireless local area network (WLAN or Wi-Fi), worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra- wideband (UWB) technology, sensor networks, mobile ad-hoc networks (MANETs) and Internet Protocol multimedia subsystems (IMS) or any combination thereof.

FIG. 1 depicts examples of simplified system architectures showing some elements and functional entities, all being logical units, whose implementation may differ from what is shown. The connections shown in FIG. 1 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that the system may also comprise other functions and structures than those shown in FIG. 1.

The example embodiments are not, however, restricted to the system given as an example but a person skilled in the art may apply the solution to other communication systems provided with necessary properties.

The example of FIG. 1 shows a part of an exemplifying radio access network.

FIG. 1 shows user devices 100 and 102 configured to be in a wireless connection on one or more communication channels in a radio cell with an access node (AN) 104, such as an evolved Node B (abbreviated as eNB or eNodeB) or a next generation Node B (abbreviated as gNB or gNodeB), providing the radio cell. The physical link from a user device to an access node may be called uplink (UL) or reverse link, and the physical link from the access node to the user device may be called downlink (DL) or forward link. A user device may also communicate directly with another user device via sidelink (SL) communication. It should be appreciated that access nodes or their functionalities may be implemented by using any node, host, server or access point etc. entity suitable for such a usage.

A communication system may comprise more than one access node, in which case the access nodes may also be configured to communicate with one another over links, wired or wireless, designed for the purpose. These links may be used for signaling purposes and also for routing data from one access node to another. The access node may be a computing device configured to control the radio resources of communication system it is coupled to. The access node may also be referred to as a base station, a base transceiver station (BTS), an access point or any other type of interfacing device including a relay station capable of operating in a wireless environment. The access node may include or be coupled to transceivers. From the transceivers of the access node, a connection may be provided to an antenna unit that establishes bi-directional radio links to user devices. The antenna unit may comprise a plurality of antennas or antenna elements. The access node may further be connected to a core network 110 (CN or next generation core NGC). Depending on the deployed technology, the counterpart that the access node may be connected to on the CN side may be a serving gateway (S-GW, routing and forwarding user data packets), packet data network gateway (P-GW) for providing connectivity of user devices to external packet data networks, user plane function (UPF), mobility management entity (MME), or an access and mobility management function (AMF), etc.

With respect to positioning, the service-based architecture (core network) may comprise an AMF 111 and a location management function (LMF) 112. The AMF may provide location information for call processing, policy, and charging to other network functions in the core network and to other entities requesting for positioning of terminal devices. The AMF may receive and manage location requests from several sources: mobile-originated location requests (MO-LR) from the user devices and mobile-terminated location requests (MT-LR) from other functions of the core network or from other network elements. The AMF may select the LMF for a given request and use its positioning service to trigger a positioning session. The LMF may then carry out the positioning upon receiving such a request from the AMF. The LMF may manage the resources and timing of positioning activities. The LMF may uses a Namf_Communication service on an NL1 interface to request positioning of a user device from one or more access nodes, or the LMF may communicate with the user device over N1 for UE-based or UE-assisted positioning. The positioning may include estimation of a location and, additionally, the LMF may also estimate movement or accuracy of the location information when requested. Connection-wise, the AMF may be between the access node and the LMF and, thus, closer to the access nodes than the LMF.

The user device illustrates one type of an apparatus to which resources on the air interface may be allocated and assigned, and thus any feature described herein with a user device may be implemented with a corresponding apparatus, such as a relay node.

An example of such a relay node may be a layer 3 relay (self-backhauling relay) towards the access node. The self-backhauling relay node may also be called an integrated access and backhaul (1AB) node. The 1AB node may comprise two logical parts: a mobile termination (MT) part, which takes care of the backhaul link(s) (i.e., link(s) between 1AB node and a donor node, also known as a parent node) and a distributed unit (DU) part, which takes care of the access link(s), i.e., child link(s) between the 1AB node and user device(s), and/or between the 1AB node and other 1AB nodes (multi-hop scenario).

Another example of such a relay node may be a layer 1 relay called a repeater. The repeater may amplify a signal received from an access node and forward it to a user device, and/or amplify a signal received from the user device and forward it to the access node.

The user device may also be called a subscriber unit, mobile station, remote terminal, access terminal, user terminal, terminal device, or user equipment (UE) just to mention but a few names or apparatuses. The user device may refer to a portable computing device that includes wireless mobile communication devices operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: a mobile station (mobile phone), smartphone, personal digital assistant (PDA), handset, device using a wireless modem (alarm or measurement device, etc.), laptop and/or touch screen computer, tablet, game console, notebook, multimedia device, reduced capability (RedCap) device, wireless sensor device, or any device integrated in a vehicle.

It should be appreciated that a user device may also be a nearly exclusive uplink-only device, of which an example may be a camera or video camera loading images or video clips to a network. A user device may also be a device having capability to operate in Internet of Things (loT) network which is a scenario in which objects may be provided with the ability to transfer data over a network without requiring human- to-human or human-to-computer interaction. The user device may also utilize cloud. In some applications, a user device may comprise a small portable or wearable device with radio parts (such as a watch, earphones or eyeglasses) and the computation may be carried out in the cloud or in another user device. The user device (or in some example embodiments a layer 3 relay node) may be configured to perform one or more of user equipment functionalities.

Various techniques described herein may also be applied to a cyberphysical system (CPS) (a system of collaborating computational elements controlling physical entities). CPS may enable the implementation and exploitation of massive amounts of interconnected ICT devices (sensors, actuators, processors microcontrollers, etc.) embedded in physical objects at different locations. Mobile cyber physical systems, in which the physical system in question may have inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals.

Additionally, although the apparatuses have been depicted as single entities, different units, processors and/or memory units (not all shown in FIG. 1) may be implemented.

5G enables using multiple input - multiple output (M1M0) antennas, many more base stations or nodes than the LTE (a so-called small cell concept), including macro sites operating in co-operation with smaller stations and employing a variety of radio technologies depending on service needs, use cases and/or spectrum available. 5G mobile communications may support a wide range of use cases and related applications including video streaming, augmented reality, different ways of data sharing and various forms of machine type applications (such as (massive) machinetype communications (mMTC), including vehicular safety, different sensors and realtime control. 5G may have multiple radio interfaces, namely below 6GHz, cmWave and mmWave, and also being integrable with existing legacy radio access technologies, such as the LTE. Integration with the LTE may be implemented, at least in the early phase, as a system, where macro coverage may be provided by the LTE, and 5G radio interface access may come from small cells by aggregation to the LTE. In other words, 5G may support both inter-RAT operability (such as LTE-5G) and inter-Rl operability (inter-radio interface operability, such as below 6GHz - cmWave - mmWave). One of the concepts considered to be used in 5G networks may be network slicing, in which multiple independent and dedicated virtual sub-networks (network instances) may be created within the substantially same infrastructure to run services that have different requirements on latency, reliability, throughput and mobility.

The current architecture in LTE networks may be fully distributed in the radio and fully centralized in the core network. The low latency applications and services in 5G may need to bring the content close to the radio which leads to local break out and multi-access edge computing (MEC). 5G may enable analytics and knowledge generation to occur at the source of the data. This approach may need leveraging resources that may not be continuously connected to a network such as laptops, smartphones, tablets and sensors. MEC may provide a distributed computing environment for application and service hosting. It may also have the ability to store and process content in close proximity to cellular subscribers for faster response time. Edge computing may cover a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, cooperative distributed peer-to-peer ad hoc networking and processing also classifiable as local cloud/fog computing and grid/mesh computing, dew computing, mobile edge computing, cloudlet, distributed data storage and retrieval, autonomic self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and/or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications).

The communication system may also be able to communicate with one or more other networks 113, such as a public switched telephone network or the Internet, or utilize services provided by them. The communication network may also be able to support the usage of cloud services, for example at least part of core network operations may be carried out as a cloud service (this is depicted in FIG. 1 by “cloud” 114) . The communication system may also comprise a central control entity, or the like, providing facilities for networks of different operators to cooperate for example in spectrum sharing.

Edge cloud may be brought into radio access network (RAN) by utilizing network function virtualization (NFV) and software defined networking (SDN). Using edge cloud may mean access node operations to be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head (RRH) or a radio unit (RU), or an access node comprising radio parts. It is also possible that node operations may be distributed among a plurality of servers, nodes or hosts. Application of cloudRAN architecture enables RAN real-time functions being carried out at the RAN side (in a distributed unit, DU 105) and non-real time functions being carried out in a centralized manner (in a centralized unit, CU 108).

It should also be understood that the distribution of functions between core network operations and access node operations may differ from that of the LTE or even be non-existent. Some other technology advancements that may be used include big data and all-lP, which may change the way networks are being constructed and managed. 5G (or new radio, NR) networks may be designed to support multiple hierarchies, where MEC servers may be placed between the core and the access node. It should be appreciated that MEC may be applied in 4G networks as well.

5G may also utilize non-terrestrial communication, for example satellite communication, to enhance or complement the coverage of 5G service, for example by providing backhauling. Possible use cases may be providing service continuity for machine-to-machine (M2M) or Internet of Things (loT) devices or for passengers on board of vehicles, or ensuring service availability for critical communications, and future railway/maritime/aeronautical communications. Satellite communication may utilize 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). A given satellite 106 in the mega-constellation may cover several satellite-enabled network entities that create on-ground cells. The on- ground cells may be created through an on-ground relay node or by an access node 104 located on-ground or in a satellite.

6G networks are expected to adopt flexible decentralized and/or distributed computing systems and architecture and ubiquitous computing, with local spectrum licensing, spectrum sharing, infrastructure sharing, and intelligent automated management underpinned by mobile edge computing, artificial intelligence, short-packet communication and blockchain technologies. Key features of 6G may include intelligent connected management and control functions, programmability, integrated sensing and communication, reduction of energy footprint, trustworthy infrastructure, scalability and affordability. In addition to these, 6G is also targeting new use cases covering the integration of localization and sensing capabilities into system definition to unifying user experience across physical and digital worlds.

It is obvious for a person skilled in the art that the depicted system is only an example of a part of a radio access system and in practice, the system may comprise a plurality of access nodes, the user device may have access to a plurality of radio cells and the system may also comprise other apparatuses, such as physical layer relay nodes or other network elements, etc. At least one of the access nodes may be a Home eNodeB or a Home gNodeB.

Furthermore, the access node may also be split into: a radio unit (RU) comprising a radio transceiver (TRX), i.e., a transmitter (Tx) and a receiver (Rx); one or more distributed units (DUs) that may be used for the so-called Layer 1 (LI) processing and real-time Layer 2 (L2) processing; and a central unit (CU) (also known as a centralized unit) that may be used for non-real-time L2 and Layer 3 (L3) processing. The CU may be connected to the one or more DUs for example by using an Fl interface. Such a split may enable the centralization of CUs relative to the cell sites and DUs, whereas DUs may be more distributed and may even remain at cell sites. The CU and DU together may also be referred to as baseband or a baseband unit (BBU). The CU and DU may also be comprised in a radio access point (RAP).

The CU maybe defined as a logical node hosting higher layer protocols, such as radio resource control (RRC), service data adaptation protocol (SDAP) and/or packet data convergence protocol (PDCP), of the access node. The DU may be defined as a logical node hosting radio link control (RLC), medium access control (MAC) and/or physical (PHY) layers of the access node. The operation of the DU may be at least partly controlled by the CU. The CU may comprise a control plane (CU-CP), which may be defined as a logical node hosting the RRC and the control plane part of the PDCP protocol of the CU for the access node. The CU may further comprise a user plane (CU- UP), which may be defined as a logical node hosting the user plane part of the PDCP protocol and the SDAP protocol of the CU for the access node. Cloud computing platforms may also be used to run the CU and/or DU. The CU may run in a cloud computing platform, which may be referred to as a virtualized CU (vCU). In addition to the vCU, there may also be a virtualized DU (vDU) running in a cloud computing platform. Furthermore, there may also be a combination, where the DU may use so-called bare metal solutions, for example application-specific integrated circuit (ASIC) or customer-specific standard product (CSSP) system-on-a-chip (SoC) solutions. It should also be understood that the distribution of functions between the above-mentioned access node units, or different core network operations and access node operations, may differ.

Additionally, in a geographical area of a radio communication system, a plurality of different kinds of radio cells as well as a plurality of radio cells may be provided. Radio cells may be macro cells (or umbrella cells) which may be large cells having a diameter of up to tens of kilometers, or smaller cells such as micro-, femto- or picocells. The access node(s) of FIG. 1 may provide any kind of these cells. A cellular radio system may be implemented as a multilayer network including several kinds of radio cells. In multilayer networks, one access node may provide one kind of a radio cell or radio cells, and thus a plurality of access nodes may be needed to provide such a network structure.

For fulfilling the need for improving the deployment and performance of communication systems, the concept of “plug-and-play” access nodes may be introduced. A network which may be able to use “plug-and-play” access nodes, may include, in addition to Home eNodeBs or Home gNodeBs, a Home Node B gateway, or HNB-GW (not shown in FIG. 1). An HNB-GW, which may be installed within an operator’s network, may aggregate traffic from a large number of Home eNodeBs or Home gNodeBs back to a core network.

Positioning technologies may be used to estimate a physical location of a user device. Herein the user device to be positioned is referred to as a target UE. For example, the following positioning techniques may be used in NR: downlink time difference of arrival (DL-TDoA), uplink time difference of arrival (UL-TDoA), downlink angle of departure (DL-AoD), uplink angle of arrival (UL-AoA), and/or multi-cell round trip time (multi- RTT). In wireless positioning, multiple positioning anchors in known locations may transmit and/or receive one or more positioning reference signals (PRS) to/from the target UE. In the uplink, a sounding reference signal (SRS) may be used as a positioning reference signal. For example, multilateration techniques may then be used to localize (i.e., position) the target UE with respect to the positioning anchors. The positioning anchors may also be referred to as anchors, anchor nodes, multilateration anchors, or reference points herein. The positioning anchors may be, for example, radio access nodes (in uplink/downlink positioning) or other UEs (in sidelink positioning).

Sidelink (SL) positioning refers to the positioning approach, where the target UE utilizes the sidelink (i.e., the direct device-to-device link) to position itself, either in an absolute manner (in case of absolute positioning, where the coordinates of the target UE are obtained in the form of global or local Cartesian coordinates) or in a relative manner (in case of relative positioning, where the location of the target UE is estimated with respect to another entity, for example another non-static UE).

Sidelink positioning involves the use of a supporting UE or a set of supporting UEs, referred to as the “anchor UE(s)”, which assist(s) the positioning session of the target UE. The anchor UE support can be implemented in various ways, including the anchor UE(s) estimating the location of the target UE, target UE obtaining positioning assistance data by the anchor UE(s), etc., and the target UE measuring reference signals from the anchor UE(s) (or vice versa) for positioning purposes.

Positioning reference units may be used in the positioning session for increasing the positioning accuracy of target UEs. A positioning reference unit (PRU) at a known location may perform positioning measurements, such as reference signal time difference (RSTD), reference signal received power (RSRP), UE receptiontransmission time difference measurements, etc., and report these measurements to a location server such as an LMF. In addition, the PRU may transmit an UL SRS for positioning to enable transmission and reception points (TRPs) to measure and report UL positioning measurements (e.g., relative time of arrival, UL-AoA, gNB receptiontransmission time difference, etc.) from PRUs at a known location. The PRU measurements maybe compared by a location server with the measurements expected at the known PRU location to determine correction terms for other nearby target UEs. The DL and/or UL location measurements for other target UEs can then be corrected based on the previously determined correction terms. From a location server perspective, the PRU functionality may be realized by a UE with a known location.

The difference between a PRU and an anchor UE is that an anchor UE may not know its own location, whereas a PRU may know its own location. PRUs may also serve as positioning anchors for the target UE, or they may just provide correction data (e.g., to LMF) to help in positioning the target UE.

In other words, PRUs located at known locations may act as reference target UEs, such that their calculated position is compared with the known location. The comparison of the known and estimated location may result in correction data, which can be used for the location estimation process of other target UEs in the vicinity, under the assumption that the same or similar accuracy determination effects apply to both the location of the PRU and the location of the other target UEs. Then, the correction data may be used for fine-tuning the location of the target UEs, thereby increasing the positioning accuracy.

The location of the UE can be calculated either at the network, for example at the LMF (in the case of LMF-based positioning), or at the UE itself (in the case of UE- based positioning).

FIG. 2 illustrates an example, where one or more PRUs 202, 202A, 202B are used for positioning a target UE 200. The PRUs maybe configured to transmit reference signals that are measured for the purpose of positioning the target UE 200. The target UE 200 may further transmit a reference signal for the purpose of positioning the target UE 200. One or more access nodes 204, 204A, 204B may measure the reference signals received from the PRU(s) 202, 202A, 202B and from the target UE 200. In case of sidelink positioning, the target UE 200 may measure reference signals received from the PRU(s) 202, 202A, 202B, and/or the PRU(s) 202, 202A, 202B may measure reference signals received from the target UE and/or from other UEs or PRUs. Measured parameters (measurement data) derived from the received reference signals may include a reference signal reception time, reference signal time difference (RSTD), reference signal angle-of-arrival, and/or RSRP, for example. The measurement data may be reported to a network element acting as a location management function (LMF) 212 configured to carry out the positioning on the basis of the measurement data. The LMF 212 may estimate a location of the target UE 200 on the basis of the received measurement data and the known locations of the PRU(s) measured by the reporting access node(s). For example, location estimation functions used in real-time kinematic positioning (RTK) applications of global navigation satellite systems may be employed. As an example, if the measurements indicate that signals received from the target UE 200 and one of the PRU(s) 202 have high correlation, the location of the target UE 200 may be estimated to be close to that PRU 202 and further away from the other PRUs 202A, 202B. A correction from the location of a given PRU 202A, 202B may be computed on the basis of the measurement data, for example by using the difference between the measurement data associated with the target UE 200 and the measurement data associated with the closest PRU 202. For example, multi-lateration measurements (multiple measurements of the RSRP, RSTD, and/or other parameters) may indicate that the target UE 200 is to a certain direction from the closest PRU 202, and the correction may be made to that direction.

There is a challenge as to what process is followed to activate PRUs for a given positioning service request. For example, the LTE positioning protocol (LPP) procedures may be followed for PRUs as well, similar to target UEs. This means that whenever a PRU is to be activated, the LMF may initiate a location service (LCS) request for that PRU. This relates to the problem described in the following.

Determining and activating the proper PRU for a positioning session, namely finding the right PRU to use its correction data for highly accurate positioning of a given target UE in the sense of low geometric dilution of precision (GDOP), within a short time (latency constraint) and with minimal overhead, is challenging. For example, in low latency positioning applications, the (accurate) position of a UE needs to be estimated within a short time. Some examples of such low latency applications may include automotive use cases, where the UE itself may initiate the positioning process for example via a mobile-originated location request (MO-LR). In other words, MO-LR means that the request to locate the target UE comes from the target UE itself.

For example, the positioning latency requirements may be set to just a few milliseconds. If we count the additional time needed to select and configure the proper PRU (that is, the PRU that is used to provide assistance data for fine-tuning the target UE location), the low latency becomes even more challenging.

Another challenging aspect is that, in contrast to global navigation satellite system (GNSS) positioning, in terrestrial positioning, the technique to refine the positioning accuracy based on correction data may require that the PRU and the target UE experience the same (or substantially same) radio conditions. That is, in order to be able to apply the same correction data for the target UE as that of the PRU, the target UE and PRU may need to be measured by the same set of TRPs and with the same conditions (e.g., line-of-sight, bandwidth, measurement capability, etc). This means that the PRU and target UE should have similar measurement capabilities and be physically located as close as possible to one another.

The LPP-based legacy approach for activating a PRU may require that the LMF initiates an LCS request to the PRU after it receives the LCS request for the target UE. Also, the LMF may need to have an as-accurate-as-possible estimation of the target UE location for identifying the proper PRU. This results in high latency, since in principle it means that the LMF needs to run two positioning processes, one after another: one process for estimating the location of the target UE; then another process to activate the PRU based on the stored database and estimate the location of the PRU. Finally, based on the estimated location of the PRU, the LMF may refine the location estimation of the target UE.

Some example embodiments may address the problem of high latency for activating and exploiting PRUs, by providing a time-efficient PRU activation process that is based on coordinating the PRUs used for a target UE via sidelink.

Some example embodiments may enable the proactive activation of appropriate PRU(s) for a positioning request by a target UE. The activation may be based on a sidelink transmission between the target UE and potential PRUs carried out before the start of the positioning session of the target UE. This allows the target UE to indicate within its own initial MO-LR which PRUs can be used by the network to refine the location estimation of the target UE.

A positioning session may be associated with signaling for activation of devices and/or signals, delivery of assistance data, reporting of measurement information, as well as estimating the location of the target UE. The positioning session may start with a positioning request.

Some example embodiments may leverage the fact that PRUs are devices that are treated as UEs by the network. In some example embodiments, devices coordinate among themselves to decide which devices will serve as PRUs of the given target UE. The target UE then evaluates which other devices can be the PRUs for its positioning session, and indicates the PRU identifiers to the network, together with its request to be positioned (e.g., MO-LR).

The proactive activation of PRUs via sidelink may result in reduced latency, which allows the PRUs to be operational at the time when the positioning of the target UE is carried out, thereby not introducing additional latency caused by additional procedures for PRU selection and activation as in legacy LMF-based procedures. Further, sidelink-based activation helps exploiting the information related to sidelink, e.g., proximity, which may not be known to the network, to help selecting the PRUs and improve the accuracy of the target UE location estimate.

Some example embodiments are described below using principles and terminology of 5G technology without limiting the example embodiments to 5G communication systems, however.

FIG. 3 illustrates a signaling diagram according to an example embodiment. This example embodiment considers the MO-LR case, and assumes that the network (e.g., corresponding serving gNBs) pre-configures UL SRS resources for PRUs, which together may result in higher gain in terms of latency.

In FIG. 3, “SgNB” refers to a serving gNB of a target UE (i.e., the “UE” in FIG. 3) or a PRU, and “NgNBs” refer to neighbor gNBs of the SgNB.

Referring to FIG. 3, in block 301, one or more network elements (e.g., corresponding serving gNBs) of a radio access network (pre) configure UL SRS transmission and/or DL PRS reception of PRUs served by different gNBs, and provide these configurations to the PRUs. These configurations may indicate the radio resources used for UL SRS transmission and/or DL PRS transmission. Alternatively, or additionally, the one or more network elements may provide assistance data that indicates active/ongoing DL PRS transmissions. Alternatively, or additionally, the one or more network elements, or another UE, or the PRU itself may (pre) configure SL PRS transmission and/or reception to the PRUs.

In block 302, the target UE that would like to initiate MO-LR transmits a sidelink broadcast message to request activation of one or more nearby PRUs. In other words, the target UE generates and transmits an activation request to one or more PRUs via sidelink, wherein the activation request comprises a request for activating the one or more PRUs for a positioning session of the target UE.

The activation request may further indicate at least one of the following: whether uplink measurements, downlink measurements, or sidelink measurements are required for positioning, a preference of selecting already active PRUs, and/or a proximity range with regard to the target UE and/or already active PRUs.

The already active PRUs may mean PRUs that are already activated for a positioning session of another target UE. It may be beneficial to reuse already active PRUs that are already consuming some radio resources. Activating new PRUs would mean a need for additional resource allocation.

The proximity range may comprise a minimum distance and/or maximum distance from the target UE and/or from the already active PRUs. For example, if the distance between the target UE and a given PRU is above or equal to the minimum distance, and/or below or equal to the maximum distance, then the PRU may activate itself.

The activation request may propagate among PRUs beyond the range of the target UE. A given PRU may determine to activate itself based on other PRUs getting activated in its proximity.

In block 303, the one or more nearby PRUs receiving the activation request process the activation request and determine whether to activate themselves, i.e., whether to accept the activation request or not. The one or more nearby PRUs may activate themselves, if they accept the activation request. The activation means that the one or more nearby PRUs may start performing at least one of the following: transmitting an UL SRS to one or more TRPs (e.g., their serving gNB), measuring a DL PRS received from the one or more TRPs (e.g., their serving gNB), transmitting an SL PRS to the target UE, and/or measuring an SL PRS received from the target UE. The PRUs may consider some criteria to determine whether to activate themselves, for example, based on further information exchanged with the target UE. For example, a given PRU may determine whether to accept the activation request based on at least one of the following: coordinates of the PRU, a list of access nodes (e.g., gNBs) visible to the target UE and to the PRU, a state of the target UE, and/or a state of the PRU. Herein the state may refer to, for example, RRC_CONNECTED state, RRCJDLE state, or RRCJNACT1VE state.

In block 304, the one or more nearby PRUs generate and transmit, to the target UE, a response to the activation request via sidelink. The response indicates whether the activation request is accepted or not by a given PRU. For example, this indication may be an acknowledgement (ACK) or a negative acknowledgement (NACK). In other words, the indication may be ACK/NACK-based, or NACK-only.

In block 305, based on the response received from the one or more nearby PRUs, the target UE transmits an MO-LR to a network element, for example to its serving gNB, wherein the MO-LR comprises an indication of one or more activated PRUs for this positioning session. For example, the MO-LR may comprise an identifier of the one or more activated PRUs, which indicated an acceptance of the activation request in their response. The serving gNB of the target UE may forward the MO-LR to a network element of a core network, for example to an LMF, via NR positioning protocol A.

In block 306, the one or more activated PRUs may transmit a UL SRS to one or more TRPs, for example to their serving gNB, based on the preconfigured resources from block 301. Alternatively, or additionally, the one or more activated PRUs may receive and measure a DL PRS from the one or more TRPs, for example from their serving gNB, based on the preconfiguration. Alternatively, or additionally, the one or more activated PRUs may transmit an SL PRS to the target UE based on the preconfiguration. Alternatively, or additionally, the one or more activated PRUs may receive and measure an SL PRS from the target UE based on the preconfiguration.

In block 307, one or more network elements may collect measurements associated with the UL SRS transmission of the one or more activated PRUs and/or the target UE. For example, the serving gNBs of the one or more activated PRUs and/or the target UE may collect the measurement information and report it to the LMF via NRPPa. Alternatively, or additionally, the one or more activated PRUs and/or the target UE may report measurement information associated with the received DL PRS and/or SL PRS to the LMF via their serving gNB or directly to the LMF via the LTE positioning protocol [LPPJ.

In block 308, the LMF utilizes the measurement information related to the one or more activated PRUs as well as the target UE to estimate the location of the target UE. For example, the LMF may select proper PRU measurements, gather correction data, and apply the correction data to the estimated target UE location. The LMF may further select measurements belonging to just a subset of the activated PRU(s), based on some criteria, such as related to characteristics and/or similarity of the collected measurement information.

It should be noted that the network, for example the LMF, may also perform other positioning procedures, such as time-based measurements, between blocks 307 and 308 for positioning the target UE.

FIG. 4 illustrates a signaling diagram according to an example embodiment. This example embodiments considers the MO-LR case, and assumes that the network (e.g., corresponding serving gNBs) pre-configures UL SRS resources for PRUs. In this example embodiment, the PRUs respond to the network instead of to the target UE.

In FIG. 4, “SgNB” refers to a serving gNB of a target UE (i.e., the “UE” in FIG. 4) or a PRU, and “NgNBs” refer to neighbor gNBs of the SgNB.

Referring to FIG. 4, in block 401, one or more network elements (e.g., serving gNBs) of a radio access network (pre) configure UL SRS transmission and/or DL PRS reception of PRUs served by different gNBs, and provide these configurations to the PRUs. These configurations may indicate the radio resources used for UL SRS transmission and/or DL PRS transmission. Alternatively, or additionally, the one or more network elements may provide assistance data that indicates active/ongoing DL PRS transmissions. Alternatively, or additionally, the one or more network elements, or another UE, or the PRU itself may (pre) configure SL PRS transmission and/or reception to the PRUs.

In block 402, the target UE that would like to initiate MO-LR transmits a sidelink broadcast message to request activation of one or more nearby PRUs. In other words, the target UE generates and transmits an activation request to one or more PRUs via sidelink, wherein the activation request comprises a request for activating the one or more PRUs for a positioning session of the target UE.

In block 403, the one or more nearby PRUs receiving the activation request process the activation request and determine whether to activate themselves, i.e., whether to accept the activation request or not. The one or more nearby PRUs may activate themselves, if they accept the activation request. The activation means that the one or more nearby PRUs may start performing at least one of the following: transmitting an UL SRS to one or more TRPs (e.g., their serving gNB), measuring a DL PRS received from the one or more TRPs (e.g., their serving gNB), transmitting an SL PRS to the target UE, and/or measuring an SL PRS received from the target UE.

The PRUs may consider some criteria to determine whether to activate themselves, for example, based on further information exchanged with the target UE. For example, a given PRU may determine whether to accept the activation request based on at least one of the following: coordinates of the PRU, a list of access nodes (e.g., gNBs) visible to the target UE and to the PRU, a state of the target UE, and/or a state of the PRU. Herein the state may refer to, for example, RRC_CONNECTED state, RRCJDLE state, or RRCJNACT1VE state.

In block 404, the one or more nearby PRUs generate and transmit, to a network element (e.g., their own serving gNB), a response to the activation request. The response indicates whether the activation request is accepted or not by a given PRU, i.e., whether or not the PRU is activated. The serving gNB of a given PRU may forward the response to an LMF via NRPPa. Thus, the PRUs may inform the network about their activation. The response may further comprise an identifier of the target UE that requested the activation, so as to let the network know about it.

In block 405, the target UE transmits an MO-LR to the network, for example to its own serving gNB, which may forward the MO-LR to the LMF via NRPPa. The network would know about the activated PRUs for this positioning session via the response transmitted by the PRUs in block 404.

In block 406, the one or more activated PRUs may transmit a UL SRS to one or more TRPs, for example to their serving gNB, based on the preconfigured resources from block 401. Alternatively, or additionally, the one or more activated PRUs may receive and measure a DL PRS from the one or more TRPs, for example from their serving gNB, based on the preconfiguration. Alternatively, or additionally, the one or more activated PRUs may transmit an SL PRS to the target UE based on the preconfiguration. Alternatively, or additionally, the one or more activated PRUs may receive and measure an SL PRS from the target UE based on the preconfiguration.

In block 407, one or more network elements may collect measurements associated with the UL SRS transmission of the one or more activated PRUs and/or the target UE. For example, the serving gNBs of the one or more activated PRUs and/or the target UE may collect the measurement information and report it to the LMF via NRPPa. Alternatively, or additionally, the one or more activated PRUs and/or the target UE may report measurement information associated with the received DL PRS and/or SL PRS to the LMF via their serving gNB or directly to the LMF via LPP.

In block 408, the LMF utilizes the measurement information related to the one or more activated PRUs as well as the target UE to estimate the location of the target UE. For example, the LMF may select proper PRU measurements, gather correction data, and apply the correction data to the estimated target UE location. The LMF may further select measurements belonging to just a subset of the activated PRU(s), based on some criteria, such as related to characteristics and/or similarity of the collected measurement information.

It should be noted that the network, for example the LMF, may also perform other positioning procedures, such as time-based measurements, between blocks 407 and 408 for positioning the target UE. It should be noted that the example embodiments of FIGS. 3 and 4 may have different benefits regarding signaling efficiency. While the example embodiment of FIG. 3 results in signaling in sidelink, it reduces the signaling on UL that is needed to inform the network. On the other hand, the example embodiment of FIG. 4 can reuse the MO- LR message, and hence may have less impact on the current signaling specifications.

FIG. 5 illustrates a signaling diagram according to an example embodiment. This example embodiment considers the activation of PRUs for mobile-terminated location request (MT-LR) with preconfigured UL SRS transmission resources. In this example embodiment, the PRUs respond to the target UE.

In FIG. 5, “SgNB” refers to a serving gNB of a target UE (i.e., the “UE” in FIG. 5) or a PRU, and “NgNBs” refer to neighbor gNBs of the SgNB.

Referring to FIG. 5, in block 501, one or more network elements (e.g., serving gNBs) of a radio access network (pre) configure UL SRS transmission and/or DL PRS reception of PRUs served by different gNBs, and provide these configurations to the PRUs. These configurations may indicate the radio resources used for UL SRS transmission and/or DL PRS transmission. Alternatively, or additionally, the one or more network elements may provide assistance data that indicates active/ongoing DL PRS transmissions. Alternatively, or additionally, the one or more network elements, or another UE, or the PRU itself may (pre) configure SL PRS transmission and/or reception to the PRUs.

In block 502, a network element of a core network, for example an LMF, receives an MT-LR for example from an LCS client that would like to know the position of the target UE.

In block 503, the LMF informs the target UE about the positioning request, and requests the target UE to activate one or more PRUs around it for a positioning session of the target UE.

In block 504, based on the request received from the LMF, the target UE transmits a sidelink broadcast message to request activation of one or more nearby PRUs. In other words, the target UE generates and transmits an activation request to one or more PRUs via sidelink, wherein the activation request comprises a request for activating the one or more PRUs for the positioning session of the target UE. The activation request may further indicate at least one of the following: whether uplink measurements, downlink measurements, or sidelink measurements are required for positioning, a preference of selecting already active PRUs, and/or a proximity range with regard to the target UE and/or already active PRUs.

In block 505, the one or more nearby PRUs receiving the activation request process the activation request and determine whether to activate themselves, i.e., whether to accept the activation request or not. The one or more nearby PRUs may activate themselves, if they accept the activation request. The activation means that the one or more nearby PRUs may start performing at least one of the following: transmitting an UL SRS to one or more TRPs (e.g., their serving gNB), measuring a DL PRS received from the one or more TRPs (e.g., their serving gNB), transmitting an SL PRS to the target UE, and/or measuring an SL PRS received from the target UE.

In block 506, the one or more nearby PRUs generate and transmit, to the target UE, a response to the activation request via sidelink. The response indicates whether the activation request is accepted or not by a given PRU. For example, this indication may be ACK/NACK-based, or NACK-only.

In block 507, based on the response received from the one or more nearby PRUs, the target UE transmits a message to a network element, for example to its serving gNB, wherein the message indicates the activation of one or more PRUs for this positioning session. For example, the message may comprise an identifier of the one or more activated PRUs, which indicated an acceptance of the activation request in their response. The serving gNB of the target UE may forward the message to the LMF via NRPPa. Alternatively, the target UE may transmit the message directly to the LMF via LPP.

In block 508, the one or more activated PRUs may transmit UL SRS to one or more TRPs, for example to their serving gNB, based on the preconfigured resources from block 501. Alternatively, or additionally, the one or more activated PRUs may receive and measure a DL PRS from the one or more TRPs, for example from their serving gNB, based on the preconfiguration. Alternatively, or additionally, the one or more activated PRUs may transmit an SL PRS to the target UE based on the preconfiguration. Alternatively, or additionally, the one or more activated PRUs may receive and measure an SL PRS from the target UE based on the preconfiguration.

In block 509, one or more network elements may collect measurements associated with the UL SRS transmission of the one or more activated PRUs and/or the target UE. For example, the serving gNBs of the one or more activated PRUs and/or the target UE may collect the measurement information and report it to the LMF via NRPPa. Alternatively, or additionally, the one or more activated PRUs and/or the target UE may report measurement information associated with the received DL PRS and/or SL PRS to the LMF via their serving gNB or directly to the LMF via LPP.

In block 510, the LMF utilizes the measurement information related to the one or more activated PRUs as well as the target UE to estimate the location of the target UE. For example, the LMF may select proper PRU measurements, gather correction data, and apply the correction data to the estimated target UE location. The LMF may further select measurements belonging to just a subset of the activated PRU(s), based on some criteria, such as related to characteristics and/or similarity of the collected measurement information.

It should be noted that the network, for example the LMF, may also perform other positioning procedures, such as time-based measurements, between blocks 509 and 510 for positioning the target UE.

FIG. 6 illustrates a signaling diagram according to an example embodiment. This example embodiment considers the activation of PRUs for MT-LR with preconfigured UL SRS transmission resources. In this example embodiment, the PRUs respond to the network instead of to the target UE.

In FIG. 6, “SgNB” refers to a serving gNB of a target UE (i.e., the “UE” in FIG. 6) or a PRU, and “NgNBs” refer to neighbor gNBs of the SgNB.

Referring to FIG. 6, in block 601, one or more network elements (e.g., serving gNBs) of a radio access network (pre) configure UL SRS transmission and/or DL PRS reception of PRUs served by different gNBs, and provide these configurations to the PRUs. These configurations may indicate the radio resources used for UL SRS transmission and/or DL PRS transmission. Alternatively, or additionally, the one or more network elements may provide assistance data that indicates active/ongoing DL PRS transmissions. Alternatively, or additionally, the one or more network elements, or another UE, or the PRU itself may (pre) configure SL PRS transmission and/or reception to the PRUs.

In block 602, a network element of a core network, for example an LMF, receives an MT-LR for example from an LCS client that would like to know the position of the target UE.

In block 603, the LMF informs the target UE about the positioning request, and requests the target UE to activate one or more PRUs around it for a positioning session of the target UE.

In block 604, based on the request received from the LMF, the target UE transmits a sidelink broadcast message to request activation of one or more nearby PRUs. In other words, the target UE generates and transmits an activation request to one or more PRUs via sidelink, wherein the activation request comprises a request for activating the one or more PRUs for the positioning session of the target UE.

In block 605, the one or more nearby PRUs receiving the activation request process the activation request and determine whether to activate themselves, i.e., whether to accept the activation request or not. The one or more nearby PRUs may activate themselves, if they accept the activation request. The activation means that the one or more nearby PRUs may start performing at least one of the following: transmitting an UL SRS to one or more TRPs (e.g., their serving gNB), measuring a DL PRS received from the one or more TRPs (e.g., their serving gNB), transmitting an SL PRS to the target UE, and/or measuring an SL PRS received from the target UE.

In block 606, the one or more nearby PRUs generate and transmit, to a network element (e.g., their own serving gNB), a response to the activation request. The response indicates whether the activation request is accepted or not by a given PRU, i.e., whether or not the PRU is activated. The serving gNB of a given PRU may forward the response to the LMF via NRPPa. Thus, the PRUs may inform the network about their activation. The response may further comprise an identifier of the target UE that requested the activation, so as to let the network know about it.

In block 607, the one or more activated PRUs may transmit UL SRS to one or more TRPs, for example to their serving gNB, based on the preconfigured resources from block 601. Alternatively, or additionally, the one or more activated PRUs may receive and measure a DL PRS from the one or more TRPs, for example from their serving gNB, based on the preconfiguration. Alternatively, or additionally, the one or more activated PRUs may transmit an SL PRS to the target UE based on the preconfiguration. Alternatively, or additionally, the one or more activated PRUs may receive and measure an SL PRS from the target UE based on the preconfiguration.

In block 608, one or more network elements may collect measurements associated with the UL SRS transmission of the one or more activated PRUs and/or the target UE. For example, the serving gNBs of the one or more activated PRUs and/or the target UE may collect the measurement information and report it to the LMF via NRPPa. Alternatively, or additionally, the one or more activated PRUs and/or the target UE may report measurement information associated with the received DL PRS and/or SL PRS to the LMF via their serving gNB or directly to the LMF via LPP.

In block 609, the LMF utilizes the measurement information related to the one or more activated PRUs as well as the target UE to estimate the location of the target UE. For example, the LMF may select proper PRU measurements, gather correction data, and apply the correction data to the estimated target UE location. The LMF may further select measurements belonging to just a subset of the activated PRU(s), based on some criteria, such as related to characteristics and/or similarity of the collected measurement information.

It should be noted that the network, for example the LMF, may also perform other positioning procedures, such as time-based measurements, between blocks 608 and 609 for positioning the target UE.

FIG. 7 illustrates a signaling diagram according to an example embodiment. This example embodiment considers the activation of PRUs for MO-LR without preconfigured UL SRS transmission resources, wherein PRUs respond to the target UE.

In FIG. 7, “SgNB” refers to a serving gNB of a target UE (i.e., the “UE” in FIG. 7) or a PRU, and “NgNBs” refer to neighbor gNBs of the SgNB.

Referring to FIG. 7, in block 701, the target UE transmits a sidelink broadcast message to request activation of one or more nearby PRUs. In other words, the target UE generates and transmits an activation request to one or more PRUs via sidelink, wherein the activation request comprises a request for activating the one or more PRUs for a positioning session of the target UE.

In block 702, the one or more nearby PRUs receiving the activation request process the activation request and determine whether to accept the activation request or not.

The PRUs may consider some criteria to determine whether to accept the activation request, for example, based on further information exchanged with the target UE. For example, a given PRU may determine whether to accept the activation request based on at least one of the following: coordinates of the PRU, a list of access nodes (e.g., gNBs) visible to the target UE and to the PRU, a state of the target UE, and/or a state of the PRU. Herein the state may refer to, for example, RRC_CONNECTED state, RRCJDLE state, or RRCJNACTIVE state.

In block 703, the one or more nearby PRUs generate and transmit, to the target UE, a response to the activation request via sidelink. The response indicates whether the activation request is accepted or not by a given PRU. For example, this indication may be ACK/NACK-based, or NACK-only.

In block 704, based on the response received from the one or more nearby PRUs, the target UE transmits a message to a network element, for example to its serving gNB, to request activation of one or more PRUs, from which a response indicating acceptance of the activation request is received. The message may be, for example, an MO-LR comprising a request to activate the one or more PRUs for this positioning session. The serving gNB may forward the message to an LMF via NRPPa. Alternatively, the target UE may transmit the message directly to the LMF via LPP.

In block 705, based on the received message, the LMF transmits an indication to one or more serving gNBs of the one or more PRUs to activate the one or more PRUs that the target UE requested to be activated. The LMF may also inform one or more neighbor gNBs about the target UE to be positioned.

In block 706, the one or more serving gNBs determine and activate an UL SRS and/or DL PRS configuration for the one or more PRUs and the target UE. Alternatively, or additionally, the one or more serving gNBs may determine a configuration for SL PRS transmission and/or reception for the one or more PRUs and for the target UE.

In block 707, the one or more serving gNBs transmit the UL SRS configuration and/or the DL PRS configuration to the one or more PRUs and to the target UE. Alternatively, or additionally, the one or more serving gNBs may transmit the SL PRS configuration to the one or more PRUs and to the target UE.In block 708, the one or more serving gNBs inform the LMF about the configured UL SRS and/or DL PRS.

In block 709, the LMF informs the one or more neighbor gNBs about the configured UL SRS and/or DL PRS.

In block 710, based on the UL SRS configuration, the one or more activated PRUs and the target UE may transmit UL SRS to one or more TRPs, for example to their own serving gNB. Alternatively, or additionally, based on the DL PRS configuration, the one or more activated PRUs and the target UE may measure a DL PRS received from the one or more TRPs, for example from their own serving gNB. Alternatively, or additionally, the one or more activated PRUs may transmit an SL PRS to the target UE based on the SL PRS configuration. Alternatively, or additionally, the one or more activated PRUs may receive and measure an SL PRS from the target UE based on the SL PRS configuration.

In block 711, one or more network elements may collect measurements associated with the UL SRS transmission of the one or more activated PRUs and the target UE. For example, the serving gNBs of the one or more activated PRUs and the target UE may collect the measurement information and report it to the LMF via NRPPa. Alternatively, or additionally, the one or more activated PRUs and the target UE may report measurement information associated with the received DL PRS and/or SL PRS to the LMF via their serving gNB or directly to the LMF via LPP.

In block 712, the LMF utilizes the measurement information related to the one or more activated PRUs as well as the target UE to estimate the location of the target UE. For example, the LMF may select proper PRU measurements, gather correction data, and apply the correction data to the estimated target UE location. The LMF may further select measurements belonging to just a subset of the activated PRU(s), based on some criteria, such as related to characteristics and/or similarity of the collected measurement information.

It should be noted that the network, for example the LMF, may also perform other positioning procedures, such as time-based measurements, between blocks 711 and 712 for positioning the target UE.

FIG. 8 illustrates a signaling diagram according to an example embodiment. This example embodiment considers the activation of PRUs for MO-LR without preconfigured UL SRS transmission resources, wherein PRUs respond to the network (instead of to the target UE). In FIG. 8, “SgNB” refers to a serving gNB of a target UE (i.e., the “UE” in FIG. 7) or a PRU, and “NgNBs” refer to neighbor gNBs of the SgNB.

Referring to FIG. 8, in block 801, the target UE transmits a sidelink broadcast message to request activation of one or more nearby PRUs. In other words, the target UE generates and transmits an activation request to one or more PRUs via sidelink, wherein the activation request comprises a request for activating the one or more PRUs for a positioning session of the target UE.

In block 802, the one or more nearby PRUs receiving the activation request process the activation request and determine whether to accept the activation request or not.

In block 803, the one or more nearby PRUs generate and transmit, to a network element (e.g., their own serving gNB), a response to the activation request. If a given PRU accepted the activation request, then the response comprises a request to be activated for the positioning session of the target UE. The response may further comprise an identifier of the target UE that requested the activation, so as to let the network know about it.

In block 804, the target UE transmits an MO-LRto the network, for example to its own serving gNB, which may forward the MO-LR to the LMF via NRPPa. The network would know about the activated PRUs for this positioning session via the response transmitted by the PRUs in block 803.

In block 805, based on the response received from the one or more PRUs, the one or more serving gNBs determine and activate an UL SRS and/or DL PRS configuration for the one or more PRUs and the target UE. Alternatively, or additionally, the one or more serving gNBs may determine a configuration for SL PRS transmission and/or reception for the one or more PRUs and for the target UE.

In block 806, the one or more serving gNBs transmit the UL SRS configuration and/or the DL PRS configuration to the one or more PRUs and to the target UE. Alternatively, or additionally, the one or more serving gNBs may transmit the SL PRS configuration to the one or more PRUs and to the target UE.

In other words, based on the request to be activated, the one or more PRUs may receive a configuration for at least one of the following: an uplink reference signal (e.g., UL SRS), a downlink reference signal (e.g., DL PRS), or a sidelink reference signal (e.g., SL PRS).

In block 807, the one or more serving gNBs inform the LMF about the configured UL SRS and/or DL PRS.

In block 808, the LMF informs the one or more neighbor gNBs about the configured UL SRS and/or DL PRS.

In block 809, based on the UL SRS configuration, the one or more activated PRUs and the target UE may transmit UL SRS to one or more TRPs, for example to their own serving gNB. Alternatively, or additionally, based on the DL PRS configuration, the one or more activated PRUs and the target UE may measure a DL PRS received from the one or more TRPs, for example from their own serving gNB. Alternatively, or additionally, the one or more activated PRUs may transmit an SL PRS to the target UE based on the SL PRS configuration. Alternatively, or additionally, the one or more activated PRUs may receive and measure an SL PRS from the target UE based on the SL PRS configuration.

In block 810, one or more network elements may collect measurements associated with the UL SRS transmission of the one or more activated PRUs and the target UE. For example, the serving gNBs of the one or more activated PRUs and the target UE may collect the measurement information and report it to the LMF via NRPPa. Alternatively, or additionally, the one or more activated PRUs and the target UE may report measurement information associated with the received DL PRS and/or SL PRS to the LMF via their serving gNB or directly to the LMF via LPP.

In block 811, the LMF utilizes the measurement information related to the one or more activated PRUs as well as the target UE to estimate the location of the target UE. For example, the LMF may select proper PRU measurements, gather correction data, and apply the correction data to the estimated target UE location. The LMF may further select measurements belonging to just a subset of the activated PRU(s), based on some criteria, such as related to characteristics and/or similarity of the collected measurement information.

It should be noted that the network, for example the LMF, may also perform other positioning procedures, such as time-based measurements, between blocks 810 and 811 for positioning the target UE.

FIG. 9 illustrates a flow chart according to an example embodiment of a method performed by an apparatus such as, or comprising, or comprised in, a positioning reference unit. The positioning reference unit may correspond to the user device 102 of FIG. 1 and/or to any of the PRUs 202, 202A, 202B of FIG. 2.

Referring to FIG. 9, in block 901, an activation request is received from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device. Herein the user device may refer to a target UE to be positioned. The activation request may be received via sidelink.

The activation request may further indicate at least one of the following: whether uplink measurements, downlink measurements or sidelink measurements are required for positioning, a preference of selecting already active positioning reference units, a proximity range with regard to the already active positioning reference units, or a proximity range with regard to the user device. In block 902, a response to the activation request is transmitted to the user device or to a network element, wherein the response indicates whether the activation request is accepted.

The apparatus may determine whether to accept the activation request based on at least one of the following: coordinates of the apparatus, a list of access nodes visible to the user device and to the apparatus, a state of the user device, or a state of the apparatus. Herein the state may refer to an RRC state, such as RRC_CONNECTED, RRCJNACT1VE, or RRCJDLE.

The network element may be a network element of a radio access network or a core network. For example, the network element may be the serving gNB of the apparatus, or an LMF.

In block 903, based on accepting the activation request, the apparatus performs at least one of the following: transmitting an uplink reference signal to one or more transmission and reception points, measuring a downlink reference signal received from the one or more transmission and reception points, transmitting a sidelink reference signal to the user device, or measuring a sidelink reference signal received from the user device.

The uplink reference signal may be, for example, an uplink sounding reference signal (UL PRS) or any other uplink reference signal. The downlink reference signal may be, for example, a downlink positioning reference signal (DL PRS) or any other downlink reference signal. The sidelink reference signal may be, for example, a sidelink positioning reference signal (SL PRS) or any other sidelink reference signal.

FIG. 10 illustrates a flow chart according to an example embodiment of a method performed by an apparatus such as, or comprising, or comprised in, a user device. The user device may also be called a subscriber unit, mobile station, remote terminal, access terminal, user terminal, terminal device, user equipment (UE), or target UE. The user device may correspond to the user device 100 of FIG. 1 and/or to the target UE 200 of FIG. 2.

Referring to FIG. 10, in block 1001, an activation request is transmitted to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the apparatus. The activation request may be transmitted via sidelink.

The activation request may further indicate at least one of the following: whether uplink measurements, downlink measurements or sidelink measurements are required for positioning, a preference of selecting already active positioning reference units, a proximity range with regard to the already active positioning reference units, or a proximity range with regard to the user device.

In block 1002, a response to the activation request is received from the one or more positioning reference units, wherein the response indicates an acceptance of the activation request.

In block 1003, based on the response, a message is transmitted to a network element, the message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

FIG. 11 illustrates a flow chart according to an example embodiment of a method performed by an apparatus such as, or comprising, or comprised in, a network element of a radio access network or a core network. For example, the network element may be an access node (e.g., a gNB) or a location management function (LMF). The network element may correspond to the access node 104 of FIG. 1 and/or to any of the access nodes 204, 204A, 204B of FIG. 2. Alternatively, the network element may correspond to the LMF 112 of FIG. 1 and/or to the LMF 212 of FIG. 2.

Referring to FIG. 11, in block 1101, a message is received from a user device or from one or more positioning reference units, the message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device. The user device may refer to a target UE to be positioned.

The message may comprise at least one of the following: an identifier of the user device, and/or an identifier of the one or more positioning reference units.

In block 1102, based on receiving the message, the apparatus obtains measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.

The apparatus may then estimate the location of the user device based at least partly on the obtained measurement information.

The blocks, related functions, and information exchanges (messages) described above by means of FIGS. 3-11 are in no absolute chronological order, and some of them may be performed simultaneously or in an order differing from the described one. Other functions can also be executed between them or within them, and other information may be sent, and/or other rules applied. Some of the blocks or part of the blocks or one or more pieces of information can also be left out or replaced by a corresponding block or part of the block or one or more pieces of information.

As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

FIG. 12 illustrates an example of an apparatus 1200 comprising means for performing the method of FIG. 9, or the method of FIG. 10, or any other example embodiment described above. For example, the apparatus 1200 may be an apparatus such as, or comprising, or comprised in, a user device or a positioning reference unit. The apparatus 1200 may correspond to the user device 100 of FIG. 1 and/or to the target UE 200 of FIG. 2. Alternatively, the apparatus 1200 may correspond to the user device 102 of FIG. 1 and/or to any of the PRUs 202, 202A, 202B of FIG. 2. The apparatus 1200 may also be called a subscriber unit, mobile station, remote terminal, access terminal, user terminal, terminal device, user equipment (UE), target UE, or positioning reference unit (PRU).

The apparatus 1200 comprises at least one processor 1210. The at least one processor 1210 interprets computer program instructions and processes data. The at least one processor 1210 may comprise one or more programmable processors. The at least one processor 1210 may comprise programmable hardware with embedded firmware and may, alternatively or additionally, comprise one or more applicationspecific integrated circuits (ASICs).

The at least one processor 1210 is coupled to at least one memory 1220. The at least one processor is configured to read and write data to and from the at least one memory 1220. The at least one memory 1220 may comprise one or more memory units. The memory units may be volatile or non-volatile. It is to be noted that there may be one or more units of non-volatile memory and one or more units of volatile memory or, alternatively, one or more units of non-volatile memory, or, alternatively, one or more units of volatile memory. Volatile memory may be for example random-access memory (RAM), dynamic random-access memory (DRAM) or synchronous dynamic random-access memory (SDRAM). Non-volatile memory may be for example read-only memory (ROM), programmable read-only memory (PROM), electronically erasable programmable read-only memory (EEPROM), flash memory, optical storage or magnetic storage. In general, memories may be referred to as non-transitory computer readable media. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM). The at least one memory 1220 stores computer readable instructions that are executed by the at least one processor 1210 to perform one or more of the example embodiments described above. For example, non-volatile memory stores the computer readable instructions, and the at least one processor 1210 executes the instructions using volatile memory for temporary storage of data and/or instructions. The computer readable instructions may refer to computer program code.

The computer readable instructions may have been pre-stored to the at least one memory 1220 or, alternatively or additionally, they may be received, by the apparatus, via an electromagnetic carrier signal and/or may be copied from a physical entity such as a computer program product. Execution of the computer readable instructions by the at least one processor 1210 causes the apparatus 1200 to perform one or more of the example embodiments described above. That is, the at least one processor and the at least one memory storing the instructions may provide the means for providing or causing the performance of any of the methods and/or blocks described above.

In the context of this document, a “memory” or “computer-readable media” or “computer-readable medium” may be any non-transitory media or medium or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

The apparatus 1200 may further comprise, or be connected to, an input unit 1230. The input unit 1230 may comprise one or more interfaces for receiving input. The one or more interfaces may comprise for example one or more temperature, motion and/or orientation sensors, one or more cameras, one or more accelerometers, one or more microphones, one or more buttons and/or one or more touch detection units. Further, the input unit 1230 may comprise an interface to which external devices may connect to.

The apparatus 1200 may also comprise an output unit 1240. The output unit may comprise or be connected to one or more displays capable of rendering visual content, such as a light emitting diode (LED) display, a liquid crystal display (LCD) and/or a liquid crystal on silicon (LCoS) display. The output unit 1240 may further comprise one or more audio outputs. The one or more audio outputs may be for example loudspeakers.

The apparatus 1200 further comprises a connectivity unit 1250. The connectivity unit 1250 enables wireless connectivity to one or more external devices. The connectivity unit 1250 comprises at least one transmitter and at least one receiver that may be integrated to the apparatus 1200 or that the apparatus 1200 may be connected to. The at least one transmitter comprises at least one transmission antenna, and the at least one receiver comprises at least one receiving antenna. The connectivity unit 1250 may comprise an integrated circuit or a set of integrated circuits that provide the wireless communication capability for the apparatus 1200. Alternatively, the wireless connectivity may be a hardwired application-specific integrated circuit (ASIC). The connectivity unit 1250 may comprise one or more components, such as: power amplifier, digital front end (DFE), analog-to-digital converter (ADC), digital-to- analog converter (DAC), frequency converter, (de) modulator, and/or encoder/decoder circuitries, controlled by the corresponding controlling units.

It is to be noted that the apparatus 1200 may further comprise various components not illustrated in FIG. 12. The various components may be hardware components and/or software components.

FIG. 13 illustrates an example of an apparatus 1300 comprising means for performing the method of FIG. 11 or any other example embodiment described above. For example, the apparatus 1300 may be an apparatus such as, or comprising, or comprised in, a network element of a radio access network or a core network. For example, the network element may correspond to any of the access nodes 104, 204, 204A, 204B, or to the LMF 112, 212. The network element may also be referred to, for example, as a network node, a radio access network (RAN) node, a next generation radio access network (NG-RAN) node, a NodeB, an eNB, a gNB, a base transceiver station (BTS), a base station, an NR base station, a 5G base station, an access node, an access point (AP), a relay node, a repeater, an integrated access and backhaul (LAB) node, an 1AB donor node, a distributed unit (DU), a central unit (CU), a baseband unit (BBU), a radio unit (RU), a radio head, a remote radio head (RRH), a transmission and reception point (TRP), a core network entity, or a location server.

The apparatus 1300 may comprise, for example, a circuitry or a chipset applicable for realizing one or more of the example embodiments described above. The apparatus 1300 may be an electronic device comprising one or more electronic circuitries. The apparatus 1300 may comprise a communication control circuitry 1310 such as at least one processor, and at least one memory 1320 storing instructions which, when executed by the at least one processor, cause the apparatus 1300 to carry out one or more of the example embodiments described above. Such instructions may, for example, include a computer program code (software) 1322 wherein the at least one memory and the computer program code (software) 1322 are configured, with the at least one processor, to cause the apparatus 1300 to carry out one or more of the example embodiments described above. Herein computer program code may in turn refer to instructions which, when executed by the at least one processor, cause the apparatus 1300 to perform one or more of the example embodiments described above. That is, the at least one processor and the at least one memory storing the instructions may provide the means for providing or causing the performance of any of the methods and/or blocks described above.

The processor is coupled to the memory 1320. The processor is configured to read and write data to and from the memory 1320. The memory 1320 may comprise one or more memory units. The memory units may be volatile or non-volatile. It is to be noted that there may be one or more units of non-volatile memory and one or more units of volatile memory or, alternatively, one or more units of non-volatile memory, or, alternatively, one or more units of volatile memory. Volatile memory may be for example random-access memory (RAM), dynamic random-access memory (DRAM) or synchronous dynamic random-access memory (SDRAM). Non-volatile memory may be for example read-only memory (ROM), programmable read-only memory (PROM), electronically erasable programmable read-only memory (EEPROM), flash memory, optical storage or magnetic storage. In general, memories may be referred to as non- transitory computer readable media. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM). The memory 1320 stores computer readable instructions that are executed by the processor. For example, non-volatile memory stores the computer readable instructions and the processor executes the instructions using volatile memory for temporary storage of data and/or instructions.

The computer readable instructions may have been pre-stored to the memory 1320 or, alternatively or additionally, they may be received, by the apparatus, via an electromagnetic carrier signal and/or may be copied from a physical entity such as a computer program product. Execution of the computer readable instructions causes the apparatus 1300 to perform one or more of the functionalities described above.

The memory 1320 may 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/or removable memory. The memory may comprise a configuration database for storing configuration data. For example, the configuration database may store a current neighbour cell list, and, in some example embodiments, structures of the frames used in the detected neighbour cells.

The apparatus 1300 may further comprise a communication interface 1330 comprising hardware and/or software for realizing communication connectivity according to one or more communication protocols. The communication interface 1330 comprises at least one transmitter (Tx) and at least one receiver (Rx) that may be integrated to the apparatus 1300 or that the apparatus 1300 may be connected to. The communication interface 1330 may comprise one or more components, such as: power amplifier, digital front end (DFE), analog-to-digital converter (ADC), digital-to- analog converter (DAC), frequency converter, (de) modulator, and/or encoder/decoder circuitries, controlled by the corresponding controlling units.

The communication interface 1330 provides the apparatus with radio communication capabilities to communicate in the cellular communication system. The communication interface may, for example, provide a radio interface to one or more user devices. The apparatus 1300 may further comprise another interface towards a core network entity such as the network coordinator apparatus or AMF, and/or to the access nodes of the cellular communication system.

It is to be noted that the apparatus 1300 may further comprise various components not illustrated in FIG. 13. The various components may be hardware components and/or software components.

As used in this application, the term “circuitry” may refer to one or more or all of the following: a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry); and b) combinations of hardware circuits and software, such as (as applicable): i) a combination of analog and/or digital hardware circuit(s) with software/firmware and ii) any portions of hardware processor(s) with software (including digital signal processor(s), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone, to perform various functions); and c) hardware circuit(s) and/or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (for example firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

The techniques and methods described herein may be implemented by various means. For example, these techniques may 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 apparatus(es) of example embodiments may 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), graphics processing units (GPUs), 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 (for example procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in a memory unit and executed by processors. The memory unit may be implemented within the processor or externally to the processor. In the latter case, it can be communicatively coupled to the processor via various means, as is known in the art. Additionally, the components of the systems described herein may be rearranged and/or complemented by additional components in order to facilitate the achievements of the various aspects, etc., described with regard 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.

It will be obvious to a person skilled in the art that, as technology advances, the inventive concept may be implemented in various ways. The embodiments are not limited to the example embodiments described above, but may vary within the scope of the claims. Therefore, all words and expressions should be interpreted broadly, and they are intended to illustrate, not to restrict, the example embodiments.

LIST OF ABBREVIATIONS

4G: fourth generation

5G: new radio / fifth generation

6G: sixth generation

ACK: acknowledgement

ADC: analog-to-digital converter

AMF: access and mobility management function

AN: access node

AP: access point

ASIC: application-specific integrated circuit

BBU: baseband unit

CN: core network

CPS: cyber-physical system

CSSP: customer-specific standard product

CU: central unit

CU-CP: central unit control plane

CU-UP: central unit user plane

DAC: digital-to-analog converter

DFE: digital front end

DL: downlink

DL-AoD: downlink angle of departure

DL-TDoA: downlink time difference of arrival

DRAM: dynamic random-access memory DSP: digital signal processor

DSPD: digital signal processing device

DU: distributed unit

EEPROM: electronically erasable programmable read-only memory eNB: evolved NodeB / 4G base station

FPGA: field programmable gate array

GDOP: geometric dilution of precision

GEO: geostationary earth orbit gNB: next generation NodeB / 5G base station

GNSS: global navigation satellite system

GPU: graphics processing unit

HNB-GW: home node B gateway

1AB: integrated access and backhaul

IMS: internet protocol multimedia subsystem loT: internet of things

LI: Layer 1

L2: Layer 2

L3: Layer 3

LCD: liquid crystal display

LCoS: liquid crystal on silicon

LCS: location service

LED: light emitting diode

LEO: low earth orbit

LMF: location management function

LPP: LTE positioning protocol

LTE: longterm evolution

LTE-A: long term evolution advanced

M2M: machine-to-machine

MAC: medium access control

MANET: mobile ad-hod network

MEC: multi-access edge computing

M1M0: multiple input and multiple output

MME: mobility management entity mMTC: massive machine-type communications

MO-LR: mobile-originated location request

MT: mobile termination MT-LR: mobile-terminated location request multi-RTT: multi-cell round trip time NACK: negative acknowledgement NFV: network function virtualization NGC: next generation core NR: new radio

NRPPa: NR positioning protocol A

PCS: personal communications services

PDA: personal digital assistant

PDCP: packet data convergence protocol P-GW: packet data network gateway PHY: physical

PLD: programmable logic device

PROM: programmable read-only memory

PRS: positioning reference signal PRU: positioning reference unit RAM: random-access memory RAN: radio access network RAP: radio access point

RAT: radio access technology Rl: radio interface

RLC: radio link control

ROM: read-only memory RRC: radio resource control

RRH: remote radio head

RSRP: reference signal received power RSTD: reference signal time difference RTK: real-time kinematic positioning RU: radio unit

RX: receiver

SDAP: service data adaptation protocol

SDN: software defined networking

SDRAM: synchronous dynamic random-access memory S-GW: serving gateway

SIM: subscriber identification module SL: sidelink SoC: system-on-a-chip

SRS: sounding reference signal

TRP: transmission and reception point

TRX: transceiver TX: transmitter

UE: user equipment

UL: uplink

UL-AoA: uplink angle of arrival

UL-TDoA: uplink time difference of arrival UMTS: universal mobile telecommunications system

UTRAN: UMTS radio access network

UWB: ultra-wideband vCU: virtualized central unit vDU: virtualized distributed unit WCDMA: wideband code division multiple access

WiMAX: worldwide interoperability for microwave access WLAN: wireless local area network

Claims

1. An apparatus comprising at least one processor, and at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to: receive an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; transmit, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and based on accepting the activation request, perform at least one of the following: transmit an uplink reference signal to one or more transmission and reception points, measure a downlink reference signal received from the one or more transmission and reception points, transmit a sidelink reference signal to the user device, or measure a sidelink reference signal received from the user device.

2. The apparatus according to claim 1, wherein the activation request is received via sidelink.

3. The apparatus according to any preceding claim, wherein the activation request further indicates at least one of the following: whether uplink measurements, downlink measurements or sidelink measurements are required for positioning, a preference of selecting already active positioning reference units, a proximity range with regard to the already active positioning reference units, or a proximity range with regard to the user device.

4. The apparatus according to any preceding claim, further being caused to: determine whether to accept the activation request based on at least one of the following: coordinates of the apparatus, a list of access nodes visible to the user device and to the apparatus, a state of the user device, or a state of the apparatus.

5. The apparatus according to any preceding claim, wherein the response transmitted to the network element comprises a request to be activated; and wherein the apparatus is further caused to: receive, from the network element, based on the request to be activated, a configuration for at least one of the following: the uplink reference signal, the downlink reference signal, or the sidelink reference signal.

6. The apparatus according to any preceding claim, wherein the response further comprises an identifier of the user device from which the activation request is received.

7. The apparatus according to any preceding claim, wherein the apparatus comprises, or is comprised in, a positioning reference unit.

8. An apparatus comprising at least one processor, and at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to: transmit an activation request to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the apparatus; receive, from the one or more positioning reference units, a response to the activation request, wherein the response indicates an acceptance of the activation request; and transmit, to a network element, based on the response, a message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

9. The apparatus according to claim 8, wherein the activation request is transmitted via sidelink.

10. The apparatus according to any of claims 8-9, wherein the activation request further indicates at least one of the following: whether uplink measurements, downlink measurements, or sidelink measurements are required for positioning, a preference of selecting already active positioning reference units, a proximity range with regard to the already active positioning reference units, or a proximity range with regard to the apparatus.

11. The apparatus according to any of claims 8-10, further being caused to: receive, from the network element, a request for activating the one or more positioning reference units for the positioning session of the apparatus, wherein the activation request is transmitted based on the request received from the network element.

12. The apparatus according to any of claims 8-11, wherein the message transmitted to the network element comprises an identifier of the one or more positioning reference units from which the response is received.

13. The apparatus according to any of claims 8-12, wherein the apparatus comprises, or is comprised in, a user device.

14. An apparatus comprising at least one processor, and at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to: receive, from a user device or from one or more positioning reference units, a message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device; and based on receiving the message, obtain measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.

15. The apparatus according to claim 14, wherein the message comprises at least one of the following: an identifier of the user device, or an identifier of the one or more positioning reference units.

16. The apparatus according to any of claims 14-15, further being caused to: transmit, to the user device, a request for activating the one or more positioning reference units for the positioning session of the user device, wherein the message indicating the activation of the one or more positioning reference units is received based on the request transmitted to the user device.

17. The apparatus according to any of claims 14-15, further being caused to: transmit, to the one or more positioning reference units, based on the message requesting the activation of the one or more positioning reference units, a configuration for at least one of the following: the uplink reference signal, the downlink reference signal, or the sidelink reference signal.

18. The apparatus according to any of claims 14-17, wherein the apparatus comprises, or is comprised in, a network element of a radio access network or a core network.

19. An apparatus comprising: means for receiving an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; means for transmitting, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and means for performing, based on accepting the activation request, at least one of the following: transmitting an uplink reference signal to one or more transmission and reception points, measuring a downlink reference signal received from the one or more transmission and reception points, transmitting a sidelink reference signal to the user device, or measuring a sidelink reference signal received from the user device.

20. An apparatus comprising: means for transmitting an activation request to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the apparatus; means for receiving, from the one or more positioning reference units, a response to the activation request, wherein the response indicates an acceptance of the activation request; and means for transmitting, to a network element, based on the response, a message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

21. An apparatus comprising: means for receiving, from a user device or from one or more positioning reference units, a message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device; and means for obtaining, based on receiving the message, measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.

22. A method comprising: receiving an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; transmitting, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and based on accepting the activation request, performing at least one of the following: transmit an uplink reference signal to one or more transmission and reception points, measure a downlink reference signal received from the one or more transmission and reception points, transmit a sidelink reference signal to the user device, or measure a sidelink reference signal received from the user device.

23. A method comprising: transmitting, by a user device, an activation request to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the user device; receiving, by the user device, from the one or more positioning reference units, a response to the activation request, wherein the response indicates an acceptance of the activation request; and transmitting, by the user device, to a network element, based on the response, a message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

24. A method comprising: receiving, from a user device or from one or more positioning reference units, a message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device; and based on receiving the message, obtaining measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.

25. A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving an activation request from a user device, wherein the activation request comprises a request for activating one or more positioning reference units for a positioning session of the user device; transmitting, to the user device or to a network element, a response to the activation request, wherein the response indicates whether the activation request is accepted; and based on accepting the activation request, performing at least one of the following: transmit an uplink reference signal to one or more transmission and reception points, measure a downlink reference signal received from the one or more transmission and reception points, transmit a sidelink reference signal to the user device, or measure a sidelink reference signal received from the user device.

26. A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: transmitting an activation request to one or more positioning reference units, wherein the activation request comprises a request for activating the one or more positioning reference units for a positioning session of the apparatus; receiving, from the one or more positioning reference units, a response to the activation request, wherein the response indicates an acceptance of the activation request; and transmitting, to a network element, based on the response, a message indicating or requesting activation of the one or more positioning reference units from which the response indicating the acceptance is received.

27. A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving, from a user device or from one or more positioning reference units, a message indicating or requesting activation of the one or more positioning reference units for a positioning session of the user device; and based on receiving the message, obtaining measurement information associated with at least one of the following: an uplink reference signal transmitted from the one or more positioning reference units, a downlink reference signal transmitted to the one or more positioning reference units, a sidelink reference signal transmitted from the one or more positioning reference units, or a sidelink reference signal transmitted to the one or more positioning reference units.