WO2023274518A1

WO2023274518A1 - Method and apparatus for providing localization based on sidelink communication

Info

Publication number: WO2023274518A1
Application number: PCT/EP2021/067963
Authority: WO
Inventors: Sami Mekki
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2023-01-05
Also published as: CN117378223A

Abstract

The present disclosure pertains to a method and a localization system that provide responses to positioning requests for user equipment involved in a sidelink communication.

Description

METHOD AND APPARATUS FOR PROVIDING LOCALIZATION BASED ON SIDELINK

COMMUNICATION

Technical Field

The present disclosure pertains to a method and apparatus for providing localization information of a first device that participates in a sidelink communication with a second device and a localization management system comprising one or more computing entities, a receiver and a transmitter.

Background

In view of the increasing amount of smart devices, such as tablets, smartphones, or laptops, that are carried along by users, the increasing demand for accurate end user equipment localization has been a major issue in the last years in view of wireless communication.

In order to provide localization information for user equipment, it has been known, for example, that a user equipment itself performs a localization method. This may be done by, for example, GPS data obtained by communicating with satellites or positioning estimation using surrounding radio access network nodes (RAN nodes).

While the known methods are able to determine the position of the user equipment, for which localization information is required with a high degree of accuracy, executing these methods involves actions to be taken by the user equipment itself. User equipment, such as smartphones, only have limited energy resources (for example battery power), which result in services that require localization information of user equipment having a negative impact on the lifetime of a battery of the such user equipment. Furthermore, the determination of the location of the user equipment by the device itself may cause further messages that have to be transferred within the telecommunication architecture, which may cause further channel utilization.

The known methods further require that the user equipment is able to provide or obtain its own localization information, for example by using GPS localization. The necessary means for doing so are, however, not always available (for example on some laptops). Moreover, when the user equipment has to take appropriate steps to obtain its localization information, this might take some time, thereby causing a delay or lag in the response to the requesting entity that requested the localization information. This might negatively influence user experience and might also have negative impact on the service quality. Thus, it may be desirable to provide localization information of user equipment or device in a way that results in less impact on the available energy resources of the user equipment as well signaling overhead. It may also be desirable to reduce the delay between issuance of a request for localization information and the provision of a response.

Summary

Embodiments of the present disclosure may allow for providing localization information of a first device that participates in a sidelink communication with a second device in a way that has reduced impact on the battery lifetime of the first device.

Embodiments of the invention may take advantage of available information in order to provide localization information with short delay, for example compared to classical methods of obtaining localization information.

Some embodiments presented herein provide a method for providing localization information of a first device that participates in a sidelink communication with a second device according to independent claim 1. Some further embodiments presented herein may provide a localization management system comprising one or more computing entities, a receiver and a transmitter in line with independent claim 10.

Further embodiments presented herein provide a computer-readable storage medium comprising computer-executable instructions that, when executed by a localization management system comprising one or more computing entities, a receiver and a transmitter, cause the localization management system to perform a method according to one or more of the embodiments presented herein, in line with claim 19.

One embodiment of the present disclosure refers to a method for providing localization information of a first device that participates in a sidelink communication with a second device, the method comprising: receiving, at a localization management system, a positioning request for the first device from a requesting entity; obtaining, at the localization management system, correlation information, wherein the correlation information indicative of location correlation between the first device and the second device based on sidelink communication; updating, at the localization management system, a position of the first device as equal to or associated to a position of the second device based on the correlation information; sending, by the localization management system, a response to the requesting entity based on the updated position of the first device. In the context of the present disclosure, the “first device” may be understood as referring to a mobile device, such as a smartphone, a laptop or a tablet or other entities that may preferably be powered by a battery having limited battery lifetime before a new loading cycle of the battery or an exchange of the battery becomes necessary. The first device may additionally or alternatively be understood as a device that, on its own, does not have capability to perform localization determination or obtain localization information associated with the device. For example, the first device may be a device that is not capable of obtaining localization information through GPS or a GPS or corresponding positioning systems. Likewise, the first device may be understood as a device for which such positioning services are at least temporarily not available (for example due to being switched off or disabled or due to low reception quality of necessary signals). The second device may be any device, for which the position is either accurately known so that it can be used to update the position of the first device with the position of the second device or for which performing methods to determine the position of the second device only has a small or negligible impact on the available energy or power. This may include, but is not limited to a second device that can be a vehicle, such as a car or any other vehicle that has preferably an energy source that has a longer lifetime than that of the first device even if localization methods are performed periodically or very often.

That a position of the first device is updated to be equal to or associated to the position of the second device based on the correlation information is intended to include cases where the position of the first device is set identical (also referred to equal) to the position of the second device, and it is also intended to include realizations where the position of the first device is not updated to be identical to that of the second device, but rather, for example, to a position that is within an area around the position of the second device. For example, this may be determined based on the accuracy with which the position of the second device is known or based on a degree of correlation between the localization of the first device and the localization of the second device or any other parameters.

With this embodiment, the determination of the position of the first device can be performed without the first device performing a method of determining its own position, thereby saving the energy of the first device.

In a further embodiment, the position of the second device is obtained by the localization management system upon receiving the positioning request, or wherein the position of the second device is periodically obtained by the localization management system.

In the first case, also the determination of the position of the second device can be done in a resource-efficient manner, specifically with respect to the required energy consumption, as the position of the second device may, in some embodiments, only be obtained upon receiving the positioning request and may not be determined in other cases. By obtaining the position of the second device periodically, the position of the second device is available at all times, so that a response to the positioning request can be provided in reduced time, as no delay due to obtaining the position of the second device by the localization management system has to be performed upon receiving the positioning request.

In one embodiment, it is provided that, after receiving the positioning request and before obtaining the correlation information, the localization management system determines whether the first device is participating in a sidelink communication, comprising determining the second device with which the first device participates in the sidelink communication.

With this embodiment, the localization management system can whether a sidelink communication and a second device are at all available for employing the methods according to the present disclosure for determining the position of the first device. The further execution of the methods according to embodiments of the present disclosure can thereby be rendered depending on whether or not sidelink communication and/or a corresponding second device can be determined, thereby executing the method for providing the localization information of a first device in a more efficient way.

In one embodiment, the correlation information is obtained from a first signal associated with a sidelink communication signal of the first device and a second signal associated with a sidelink communication signal of the second device.

The first signal and the second signal used to obtain the correlation information may, for example, encompass a signal power of the first signal and a signal power of the second signal. Also other characteristics of the first signal and the second signal associated with the sidelink communication signal of the first device and the second device respectively, may be employed to obtain the correlation information. With this embodiment, reliable evaluation of potential spatial adjacency of the first device and the second device may be achieved.

It may further be provided that the correlation information is obtained from a correlation coefficient and the correlation coefficient is obtained from a first variance associated with a sidelink communication signal of the first device and a second variance associated with a sidelink communication signal of the second device.

The variance may be a variance of the signal strength (for example, the signal power received at an RAN node of the localization management system) or another variance that can be obtained from the sidelink communication signals. In some embodiments, the correlation coefficient may range from 0 to 1, wherein 0 denotes no correlation between the location of the first device and the location of the second device, whereas the value 1 may denote exact correlation of the location of the first device and the second device.

In one embodiment, the correlation information comprises at least one of: a correlation value, an identification of the first device, an identification of the second device, a first signal power associated with a sidelink communication signal of the first device or a value derived from the first signal power, a second signal power associated with a sidelink communication signal of the second device or a value derived therefrom, a value derived from the first signal power and the second signal power, an indication of a degree of correlation, an indication that the position of the first device is equal to or associated with the position of the second device, a first variance associated with the sidelink communication signal of the first device, a second variance associated with the sidelink communication signal of the second device, a value derived from a time series of a value associated with the sidelink communication signal of the first device, a value derived from a time series of a value associated with the sidelink communication signal of the second device.

At least some of these characteristics can be used to determine, with high accuracy, whether it is appropriate to update the position of the first device with the position of the second device, so that the position of the first device is either equal to or associated to a position of the second device. Furthermore, at least some of these values or characteristics obtained from the at least one of the signals of the first device and the second device may be advantageously used to determine whether to update the position of the first device as equal to the position of the second device or whether to update the position of the first device as being associated to the position of the second device.

It may be provided that the localization management system comprises a RAN node and/or a location management function, LMF, and/or an access and mobility management function, AMF.

In one embodiment, the correlation information comprises a correlation value and the method further comprises determining if the correlation value is larger than or equal to a threshold and, if it is determined that the correlation value is not larger than or equal to the threshold, the localization management system requests the first device to perform a reference signal time difference measurement.

The comparison of the correlation value with a threshold can be implemented in a computationally efficient way that allows for fast determination of whether the first device is to be instructed to perform a reference signal time difference measurement for determining its own position, thereby reducing the delay between receiving the positioning request and providing a response to the positioning request, which for example, may encompass localization information comprising the updated position of the first device.

In one embodiment, the first device is or comprises at least one of a mobile phone, a smart phone, a tablet, a laptop; and/or the second device is or is part of a vehicle, wherein the vehicle optionally is at least one of a car, a train, a bus; and/or the requesting entity is the first device or a third device that is different from the first device and the second device.

By combining a first device according to this embodiment with a second device that is or is at least part of a vehicle, the constraints following from the first device having only limited battery lifetime can be overcome while not resulting in a disadvantageous increase of the energy consumption at the second device, or at least an increase in the energy consumption at the second device that is negligible compared to the overall energy consumption of the second device.

Furthermore, the advantages of the embodiments according to the present disclosure can still be achieved even if the requesting entity is the first device itself or a third device, such as a remote service.

In one embodiment, A localization management system comprising one or more computing entities, a receiver and a transmitter, wherein: the receiver can receive a positioning request for the first device from a requesting entity; the one or more computing entities can obtain correlation information, wherein the correlation information is indicative of location correlation between the first device and the second device based on sidelink communication; the one or more computing entities can update a position of the first device as equal to or associated to a position of the second device based on the correlation information; the transmitter can send a response to the requesting entity based on the updated position of the first device

With this system, the advantages described above can be realized when serving the positioning requests from requesting entities.

It can further be provided that the one or more computing entities can obtain the position of the second device upon receiving the positioning request, or wherein the one or more computing entities can obtain the position of the second device periodically. Obtaining the position of the second device upon receiving the positioning requests allows for only performing a determination of the position of the second device if there is a need to do so. This does not exclude cases where the position of the second device is nevertheless determined depending, for example, on other requests that do not pertain to positioning requests of or related to the first device.

The alternative of obtaining the position of the second device periodically ensures that the position of the second device is available at all times, at least with some degree of accuracy. For example, the position of the second device can be obtained every second or every ten seconds if this is considered appropriate. Instead of a fixed time period, the periodicity may also be set depending on the localization management system or other entities in the network. For example, a required periodicity may be set by the LLP protocol. In another example, the periodicity may be set depending on a position accuracy that is targeted by the GPS chip set on the second device itself. Instead of a GPS chip set, also other positioning system chip sets may be provided that determine a targeted position accuracy.

In one embodiment, the one or more computing entities can determine, after receiving the positioning request and before obtaining the correlation information, whether the first device is participating in a sidelink communication, comprising determining the second device with which the first device participates in the sidelink communication.

With this determination, it can be ensured that further procedures are only carried out by the localization management system in response to a positioning request if either the first device is determined to participate in a sidelink communication or not.

In a further embodiment, the one or more computing entities can obtain the correlation information from a first signal associated with a sidelink communication signal of the first device and a second signal associated with a sidelink communication signal of the second device.

The first and second signals can, for example, be received at a radio access network node (RAN-node) and can be further processed by this node or another entity of the localization management system. Specifically, a signal power of the first signal and a signal power of the second signal can be used to obtain the correlation information by, for example, processing the time-dependent solution of the first signal and the second signal or the first signal power and the second signal power, respectively.

In a further aspect, the one or more computing entities can obtain the correlation information from a correlation coefficient and/or can obtain the correlation coefficient from a first variance associated with a sidelink communication signal of the first device and a second variance associated with a sidelink communication signal of the second device.

Obtaining the correlation information from a correlation coefficient can be computationally efficient, as the involved calculations and further processing might be implemented in a computationally efficient way.

The correlation information may comprise at least one of: a correlation value, an identification of the first device, an identification of the second device, a first signal power associated with a sidelink communication signal of the first device or a value derived from the first signal power, a second signal power associated with a sidelink communication signal of the second device or a value derived therefrom, a value derived from the first signal power and the second signal power, an indication of a degree of correlation, an indication that the position of the first device is equal to or associated with the position of the second device, a first variance associated with the sidelink communication signal of the first device, a second variance associated with the sidelink communication signal of the second device, a value derived from a time series of a value associated with the sidelink communication signal of the first device, a value derived from a time series of a value associated with the sidelink communication signal of the second device.

With these characteristics and/or values, the correlation information can provide a reliable indication of whether the first position can or is to be updated with the position of the second device.

In one embodiment, the localization management system comprises a RAN node and/or a location management function, LMF, and/or an access and mobility management function, AMF.

In some embodiments, it can further be provided that the localization management system can be adapted to receive the positioning request at the LMF and, upon receiving the positioning request at the LMF, to obtain, by the RAN-node, the correlation information and to provide, depending on the correlation information, from the RAN-node to the LMF, information that is indicative of the correlation information, wherein the LMF is adapted to obtain, upon receiving the information at the LMF, the position of the second device and to update the position of the first device as equal to or associated to the position of the second device and to provide a response to the requesting entity based on the updated position of the first device. With this embodiment, the LMF is free from having to determine the correlation information, as this is done by the RAN-node that receives the signal from the first device and the second device. The LMF may thus only be provided with the correlation information or information that is indicative of the correlation information. This can allow the LMF to make a decision on whether or not to update the position of the first device with the position of the second device.

In a further embodiment, the information provided from the RAN-node to the LMF can indicate the position of the first device as being equal to or associated to the position of the second device. The further processing at the LMF can thereby be efficiently reduced by responding to the positioning request with the updated position of the first device as equal to or associated to the position of the second device. Thereby, the LMF can process and respond to a large number of positioning requests while the actual calculation of the correlation information can be done in a decentralized way by the RAN-nodes.

It can also be provided that the correlation information comprises a correlation value and the one or more computing entities can determine if the correlation value is larger than or equal to a threshold and can request, if it is determined that the correlation value is not larger than or equal to the threshold, the first device to perform a reference signal time difference measurement.

With this embodiment, the localization management system can ensure that a response to the positioning request is provided in any case irrespective of whether the position of the first device can be obtained by updating it to the position of the second device based on the correlation information, or if such position of the second device is not available or does not indicate a corresponding correlation, by using a reference signal time difference measurement.

In a further embodiment, a computer-readable storage medium is provided that comprises computer-executable instructions that, when executed by a localization management system comprising one or more computing entities, a receiver and a transmitter, cause the localization management system to perform a method according to any of the above embodiments.

With this embodiment, a localization management system can, for example, be adapted to perform the method according to any of the above embodiments by executing the computer- executable instructions provided on the computer-readable storage medium. As the infrastructure, i.e. hardware components, which may be used for performing methods according to embodiments of the present disclosure can be the same as already currently employed, this serves for using the already available telecommunication infrastructure without having to apply modifications to the same, which thereby results in a cost-efficient implementation of the present disclosure. Brief description of the drawings

Figure 1 shows types of V2X applications;

Figure 2 shows LLP configuration for control- and user-plane positioning in E-UTRAN or NG-RAN (TS 37.355 V16.1.0);

Figure 3 shows a table of supported versions of user equipment positioning methods in TS 38.305 V16.1.0;

Figure 4 shows location service support by NG-RAN in TS 38.305 V16.1.0;

Figure 5 shows a LPP location information transfer procedure in TS 37.355 V16.1.0;

Figure 6 shows user equipment positioning operations to support MT-LR or NI-LR in TS

38.305 V16.1.0; Figure 7 shows an example use case of a V2X and V2Ps; Figure 8 shows an example V2X initiated location information delivery procedure; Figure 9 shows an example LMF initiated location information delivery procedure; Figure 10 shows V2X and V2Ps use case with two moving profiles; Figure 11 shows an example of a power profile of a received signal from V2X as seen by eNB;

Figure 12 shows a further example of a power profile of a received signal from V2P1 as seen by eNB;

Figure 13 shows a further example of a power profile for a received signal from V2P2 as seen by eNB; Figure 14 shows a variance of the received power profiles as computed by the eNB; Figure 15 shows a V2P (user equipment) positioning update method in a sidelink communication with V2X with correlation computation on the NG-RAN node according to one embodiment;

Figure 16 shows a V2P (user equipment) positioning update method in a sidelink communication with V2X with correlation computation on the LMF according to one embodiment;

Figure 17 shows an embodiment for a location service in a sidelink communication with correlation computation at an RAN-node side;

Figure 18 shows one embodiment for a location service in a sidelink communication with correlation computation at the LMF side;

Figure 19 shows a further embodiment for V2X position update when correlation with the target user equipment meets with a threshold and computed at the LMF side;

Figure 20 shows a schematic depiction of an architecture of a localization management system according to one embodiment; Figure 21 shows a general flow diagram of an exemplary method for providing localization information of a first device that participates in a sidelink communication with a second device;

Figure 22 shows a further flow diagram of an embodiment for providing localization information of a first device that participates in a sidelink communication with a second device, wherein the correlation information is obtained at the RAN node;

Figure 23 shows a further flow diagram of an alternative embodiment for providing localization information of a first device that participates in a sidelink communication with a second device, wherein the correlation information is obtained at a localization management function; Figure 24 shows a further flow diagram of an embodiment comprising updating the position of the second device;

Figure 25 shows a further schematic embodiment of a localization management system according to one of embodiment. Detailed Description

The present disclosure will now be further described with respect to the accompanying figures. It is noted that the embodiments described in the following specifically with respect to Figures 1 to 19 are intended also to be combined with the more general description of the embodiments of the present disclosure in line with Figures 20 to 25.

Accurate and fast user equipment (UE) localization has been always the major issue of wireless communication in orderto provide the best services according to the situation. Indeed, the knowledge of UE localization will improve the radio resources allocation such as for high data rate transmission, or for autonomous driving, etc.

The procedure for UE localization, as it is described in 3GPP standard, does not take into account the available side services in order to retrieve the UE position, which might lead to resources loss or under use of available resources especially when sidelink (V2X to UE) communication is available and supported by the network. Thus, the UEs who are inside the vehicles (V2X) are sharing the same position as the V2X.

Sidelink communication has been described in 3GPP standard of 4G or 5G in order to support Vehicle-to-vehicle (V2V) and V2X services. The V2X is referring to as vehicle to everything, which could be one of the following four different types:

• Vehicle-to-vehicle (V2V)

• Vehicle-to-infrastructure (V2I)

• Vehicle-to-Network (V2N)

• Vehicle 2 pedestrian (V2P)

Figure 1 summarize the different types of V2X application.

As the future car will, for example and among other more sophisticated functionalities, be able to support autonomous driving and sidelink communication, the car localization is updated frequently, on its initiative or on the demand of the location server, with few impact on the battery consumption. In general, it may also be the case that the updating of the car localization even periodically or frequently does not significantly impact the available energy of the car, thus allowing, in some embodiments, also for updating of the localization of the car several hundred or thousand times a minute.

Figure 2 depicts car positioning in Evolved Universal Terrestrial Radio Access Network (E- UTRAN) or Next Generation-Radio Access Network (NG-RAN) Embodiments of the present disclosure pertain, among others, to a method and apparatus that take advantage of the sidelink communication, once established between the V2X and target UE. The method for providing localization information of a first device that participates in a sidelink communication with a second device, in some embodiments, comprises: receiving, at a localization management system, a positioning request for the first device from a requesting entity; obtaining, at the localization management system, correlation information, wherein the correlation information indicative of location correlation between the first device and the second device based on sidelink communication; updating, at the localization management system, a position of the first device as equal to or associated to a position of the second device based on the correlation information; sending, by the localization management system, a response to the requesting entity based on the updated position of the first device.

The method may allow for optimizing the radio resource utilization by reducing the unnecessary exchanged protocol between the target UE and the location server and retrieve the UE position from V2X position. The proposed procedure according to embodiments of the present disclosure may provide a faster UE localization than applying the classical method as described in the standard. Hence, the UE localization accuracy is improved compared to the classical method especially when the target UE is moving.

The UE localization has been defined in 3GPP standard to meet the demand of certain service such as navigation or radio resources allocation for higher data rate transmission. Thus, in 3GPP standard, different methods for UE localization has been described according to the available methodology as showed in the table in figure 3.

Each method has its accuracy limit and drawbacks. Such as, global navigation satellite system (GNSS) localization method provides high accurate position in outdoor, however it suffers from high energy consumption. Indeed, this method quickly drains the UE’s battery life if the UE position is updated very often or periodically. The sensor based localization suffers essentially from sensors quality and from unpredictable user’s movement which will limit the UE position tracking. The UE-based position, i.e. Terrestrial Beacon System (TBS), Downlink Time Difference Of Arrival (DL-TDOA), and Downlink Angle-of-Departure (DL-AoD), depends essentially on the received signal quality and on the algorithm used at UE side for positioning. The NG-RAN UE positioning method retrieves the UE measurement in order to offload the computational complexity on the location server, which will save the UE energy and get the UE position. However, this process comes with high cost of exchanged signaling (such as LTE Positioning Protocol (LPP) messages) and allocated resources for signal measurement.

The present disclosure, in some embodiments, pertains to RAN UE positioning and/or NG-

RAN UE positioning. The UEs localization in 5G standard are initiated either by the mobile or the network or a third party entity through different protocols (Mobile Originated Location Request (MO-LR), Mobile Terminated Location Request (MT-LR), Network Induced Location Request (NI-LR)) as showed in figure 4 [TS 38.305 V16.1.0] where

- The LMF (Location management function) processes the location services request which may include transferring assistance data to the target UE to assist with UE-based and/or UE- assisted positioning and/or may include positioning of the target UE. The LMF then returns the result of the location service back to the AMF.

- The AMF (Access and mobility Management Function) receives all connection and session related information from the User Equipment (UE) (N1/N2) but is responsible only for handling connection and mobility management tasks

Each location request sent by the server to the target or sent by the UE to the server for location assistance is handled by the LPP protocol. Thus, the UE localization requires radio resources allocation for LPP protocol exchange and Reference Signal Time Difference (RSTD) measurement feedback as shown in figure 5.

However, when the UE is involved in a sidelink communication as defined in current standard(like for example and without limitation [TR37.985 V16.0.0]), the classical UE- localization procedure, as described previously, might lead to loss or under use of radio resources. Thus, embodiments disclosed herein allow for minimizing the unnecessary exchanged radio resources while performing UE localization who is involved in sidelink communication.

Embodiments of the present disclosure pertain, among others, to a solution to retrieve the UE position involved in a sidelink communication with a V2X without the need to initiate the localization services as described in the standard. Indeed, the classical localization procedure involves several LPP message that are exchanged between the target UE and the LMF in order to retrieve the UE position as shown in shown in figure 6.

Embodiments disclosed herein allow for saving these LPP messages and map the UE position to the one of the V2X to which the target UE is attached. To do so, available information that is/are common to V2X and the target UE when they are at the same position or very close to each other may be used according to some embodiments. For example, the propagation channel profile of target UEs who are inside the V2X are very correlated with the one of V2X (i.e. pathloss profile, multipath reflection profile, etc.). Even if the channel propagation of UEs inside the vehicle (V2Ps) are distorted due to the vehicle structure, the channel profile of V2Ps and V2X are proportional. The channel correlation between the target UE (V2P) and V2X could be extracted from channel propagation features, such as amplitude channel variance over a time window, channel coefficient, median, third quartile etc. (refer to [Lin2019, Table III] for the list of features). In order to select the best feature for channel propagation, embodiments may apply a Minimum Redundancy Maximum Relevance (mRMR) algorithm as described in [Lin2019]

Embodiments of the present disclosure may allow for reducing the unnecessary radio resource, i.e. the exchanged LPP message and other message used for UE localization when the target UE is involved in sidelink communication.

In the above and in the following, reference has been and will be made to literature and standards listed below. The content of which is herewith incorporated by reference in its entirety.

Embodiments of the present disclosure may allow for optimizing the radio resources and reduce the exchanged message, during the localization process, between the location server and the target UE who is involved in a sidelink communication that is supported by the network. To do so, a correlation between one or more features of the propagation channel of the target UE and V2X may be obtained, for example by computational calculation.

Once the correlation of the one or more channel features between the target UE and V2X is computed and assessed that they are highly correlated, it can be determined that the position of the target UE is the same as that of V2X. Thus, the UE position can be updated without the need to perform new measurement by the target UE or initiate LPP message exchange with the location server. In some embodiments, it may be provided that, if the correlation of the one or more channel features between the target UE and V2X does not reach a critical or satisfactory threshold, the position of the target UE is updated following the conventional positioning procedure.

In the following, exemplary embodiments that describe how sidelink communication that is supported by cellular network can be used in order to retrieve the position of the target. This can be done without overloading the network with unnecessary messages.

To this end, two UEs attached to V2X (the car, for example) through a sidelink communication as shown in figure 7 will be considered as an example.

In this configuration, only V2P_t is inside the car, however F2 P₂ is a pedestrian user who is in the range of sidelink communication. The V2X position is updated periodically since the energy consumption does not significantly affect the battery life as in mobile phone. The V2X position may, for example, be updated based on GNSS measurement where the V2X position is sent to the LMF on V2X initiative as shown in figure 8 or on LMF initiative as shown in figure 9 according to 3GPP standard TS 38.305 V16.1.0.

If GNSS information is not available at V2X level, the LMF retrieve the V2X position based on the radio signal measurement as described in the standard and shown in figure 4.

The process of V2X positioning is out of the scope of the present disclosure but may be done in line with one of several known ways on the further descriptions pertains to V2Ps (UEs) localization and their update, in order to minimize the radio resources usage. The initialization of the sidelink communication between V2X and V2P follows the 3GPP standard and will not be treated here specifically.

In one embodiment, a case where the car V2X is moving at speed S_t = 50 km/h, for example, so the user V2P_t too, while the pedestrian V2 P₂ is walking at speed S_t = SAkm/h, for example, as shown in figure 10.

The car V2X and the pedestrian V2 P₂ are moving in the same direction as shown in the figure 10. Since, V2X, V2P_t and V2 P₂ are involved in sidelink communication, their respective channel profile, as seen or received by the eNB (which may be a RAN-node or an NG-RAN node) at f_c = 2 GHz at a high of 15m, are given in figures 11 , 12 and 13.

In order to be able to update the position of V2P_t as equal to the position of V2X, in some embodiments, a variance of the received signal power over a sliding time window W may be obtained. For each UE connected to the network involved in a sidelink communication, a vector of variance, i.e. sg_2c, s v2_Pt> ^snir₂ ^may be obtained. The result of channel variance over time for V2X, V2P and V2 P₂ are displayed in figure 14.

Then, in some embodiments, correlation coefficients of the variance vectors may be obtained. The correlation coefficient between two variance vectors A = (A_lr

...,A_N ) and B = (b_ί, ,Bi , ... , B_N ) is given by

where m_A and s_A are the mean and standard deviation of variance vector A, respectively, and m_B and s_B are the mean and standard deviation of variance vector B. Thus, the correlation coefficient between V2X and V2P_t and between V2X and V2 P₂ may be obtained using the above equation. The result over a sliding time window of 1s for the example values indicated above shows that p(o_y2X, s _2Ri) = 0.9, wheras p(o_y2X, s_g2r2) = 0.03.

These values are, of course, only exemplarily and depend on multiple factors, like distortion of received signals, changes in velocity of the pedestrian user and/or the car or the like. The values indicated here are thus for explanatory purpose only.

According to the above results, it can be seen that, in the exemplary case, the correlation coefficient between channel variance of V2X and V2P₁ is close to 1, thus, it may, in some embodiments, be determined that V2X and V2P₁ have the same position since their one or more channel features are highly correlated. So, the position of V2P₁ may, in some embodiments, be updated at the location server without initiating LPP procedure with the target UE or without requesting V2P₁ to perform new channel measurement.

However, the correlation coefficient between V2X and V2 P₂ is close to zero in the above example. This means that the channel profile (or the one or more channel features) of V2 P₂ is less correlated with the channel profile of V2X. So, V2 P₂ has a different position than V2X. Thus, the localization of V2 P₂ may be extracted in another way, such as using the described procedure in the 3GPP standard.

In one embodiment, when the position request of the target UE is received by the LMF, the LMF may instigate one or more NRPPa (NR Positioning Protocol A) procedures between the NG-RAN Node and the LMF. Thus, the NG-RAN node may first check if the target UE is involved into a sidelink communication or not.

If it is determined that the target UE is involved into a sidelink communication, the NG-RAN may compute the channel correlation in line with one or more embodiments already explained above, as seen by the NG-RAN node, between the target UE and the V2X to which the target UE is attached.

In some embodiments, if the correlation meet the threshold, the NG-RAN may inform the LMF that the target UE has the same position as the V2X. The NG-RAN could use the TRP ID (Transmission-Reception Point ID) to send back the ID of V2X to which the target UE is attached in order to map the position of target UE with the position of V2X. Thus, this procedure will save LPP signaling message between the LMF and the UE. With this process it is possible to retrieve the position of the target UE when the UE is involved in a sidelink communication without sending initiating LPP messages exchange between the LMF and the target UE.

In one embodiment, the correlation computation may be offloaded to the LMF. The NG-RAN node transmits to the LMF the channel information of UEs that are involved in a sidelink communication through NRPPa procedure, such as the observed channel of V2X and V2Ps. Then the LMF computes the correlation between these channel features in order to be able to decide if the UEs have the same position based on the correlation procedure described in the above embodiment.

For both procedures, if the correlation does not reach a fixed threshold, the LMF may initiate LPP procedures with the target UE in order to retrieve the UE position as described in the standard.

Figures 15 and 16 display the flowchart of the above embodiments that summarize the procedure of UE positioning involved in sidelink communication. These procedures may save the radio resources necessary for localization and save time for positioning update.

One or more embodiments of the present disclosure can be shown to be standard compliant. This will be explained in the following with respect to figure 17. The detailed flow diagram in figure 17 is provided so that all the exchanged messages on the air interface are removed and all the processes are performed on LMF or NG-RAN node server as described in the above embodiments. In what follows, it will be assumed that V2X position (for example the position of the car) is known by the LMF, where its position update is performed in a separate procedure.

The first case described below refers to the embodiments where correlation processing is performed at the NG-RAN node side.

As mentioned previously, the V2X positioning and the sidelink communication initialization with the target UE (i.e. V2P) are established in one or more separate procedures. These procedures are depicted in the first two boxes 1701 (for periodically updating the position of the V2X) and 1702 for establishing the sidelink communication just to recall the context.

In order to get the UE position the following steps are performed: In a first step, any entities or devices, such as a 5GC entity or a UE or the AMF, that requests the position of a target UE, send the request to the AMF, for example the requests 1703 and 1704. Then, the AMF will transfer the location service request to an LMF as indicated by 1705. These both steps are the same as described in 3GPP standard.

In a next step denoted with 1706, the LMF may instigate location procedures with the serving NG-RAN node - e.g. to obtain positioning measurements or assistance data. Once the NG- RAN receives the request about the target UE from the LMF, the NG-RAN checks first if the target UE is involved into sidelink communication with V2X, as denoted with 1707.

If the target UE is attached to V2X through a sidelink communication, the NG RAN performs the correlation computation in 1708 between the V2X and the target UE, i.e. V2P, on the observed signal from each devices without interrupting the UEs communication.

If the result of correlation is close to 1 (or above a fixed threshold), the NG-RAN informs the LMF that the target UE is attached to V2X with the strong channel correlation through NRPPa message as described in the above embodiment, for example by sending a corresponding message 1709. Then, the LMF retrieves the position of the V2X in 1710 and updates in 1711 the UE position as equal to V2X position.

However, if the correlation result does not reach the fixed threshold, the legacy procedure is applied where the LMF initiate the UE procedure through as detailed in the standard as shown in figure 4.

As part of a service location response 1712, the LMF may provide the location information comprising, for example, the updated position of the V2P to the AMF. Location service responses 1713, 1714 and 1715 may then be provided from the LMF to the devices that requested the position of the V2P, like the 5G LCS entities or the V2P device itself.

In a second case, it will now be described how the procedure of correlation computation between the observed signal of V2X and V2P could be performed at the LMF side. The difference with the first case is on the exchanged message between the (NG-)RAN node and the LMF. As shown in figure 18, when the LMF may instigate location procedures with the serving NG-RAN node in 1806, the NG-RAN node informs the LMF that the target UE is attached to V2X through NRPPa message in 1807.

Then, in 1808 the LMF may ask the NG-RAN to send observed signal of V2X and the target UE. In 1809 the NG-RAN will listen to the exchanged message between the V2X and the target UE without interrupting the sidelink communication and send the measurement to LMF 1810. Once the LMF receives the observed signals, the LMF computes 1811 the correlation between V2X and the target UE on observed signal. Then, based on the result, for example if the correlation result is close to 1 or above a predefined threshold, the LMF retrieves 1812 the V2X position and updates 1813 the position of the target UE as equal to the position of V2X. If the correlation result between V2X and UE does not reach a certain threshold, the LMF performs the classical procedure as described in the standard though initiating the UE procedure which involve LPP message exchange with the target UE.

In step 1814, the LMF sends a location service response to the AMF as in figure 17. Also in line with the embodiments described in figure 17, the AMF respond the initial request from the corresponding entities or devices in 1815, 1816, 1817.

If V2X position is unavailable or not updated on the LMF side and the position of the target UE who is attached to V2X is requested, a legacy procedure as described in the standard may be applied in order to retrieve the position of the target UE. In other hand, once the position target UE is retrieved using the legacy procedure, the LMF could update the V2X position if the correlation result meet the threshold. Figure 19 shows a proposal for V2X position update when its position is unknown but the correlation between V2X and the target UE satisfies the threshold.

The flow diagram depicted in Figure 19 corresponds in parts to what was describes with respect to Figures 17 and 18. The steps 1901 to 1910 will thus not be described here in further detail, but reference is made to steps 1701 to 1709 of Figure 17 and the steps 1801 to 1810 of Figure 18.

In contrast to Figures 17 and 18, during step 1911 , the LMF determines that the position of the vehicle is not available. This may be determined by the LMF upon querying a database for the position of the vehicle upon having received, in step 1910, information on the signals of the target UE and the vehicle for example from the RAN-node, as was explained above already in relation to Figures 17 and 18.

Upon this determination, the LMF may cause the target UE to initiate a procedure for obtaining the localization information in step 1912. This may, for example, encompass using, by the target UE, the GPS system and integrated chips of the target UE to obtain localization information of the target UE or any other approach for obtaining localization information. Once this localization information is then obtained by the LMF, a location service response may be provided in step 1913 to the AMF which may then provide one or more location service responses in steps 1914 to 1916 based on the localization information obtained by the LMF.

Additionally, the position of the vehicle may be determined or updated by using the localization information of the target UE that was obtained in step 1912. As it was determined that there is a correlation between the position of the target UE and the position of the vehicle, this can be used here to update the position of the vehicle to the position of the target UE. Figure 20 generally depicts an architecture of a localization management system 2001 that can interact with a first device 2021 and a second device 2022 as well as a requesting entity 2023 according to one embodiment.

The localization management system 2001 may generally be regarded as an entity that is adapted to perform the methods disclosed therein. For this purpose, the localization management system 2001 may, without limitation, comprise a localization management function 2011, LMF, and a radio access network node 2012, RAN-node. These may be in communication with each other, as indicated by the dashed line between them. The localization management system may further comprise an access and mobility management function 2013, AMF. Also the AMF may be in communication with at least one or both of the LMF and the RAN-node.

Generally, the localization management system 2001 may be adapted to receive a positioning request from the requesting entity 2023. This positioning request may, for example, be a positioning request for a first device 2021 and may, at least in some embodiments, pertain to a positioning request for localization information for the first device 2021.

The requested localization information may specifically pertain to information that specifies or is indicative of the position of the first device 2021 at least at a given point in time. For example, the localization information requested by the positioning request may specify the position of the first device 2021 at the point in time where the positioning request is received at the localization management system 2001 or in a short time frame immediately after the point in time at which the positioning request was received at the localization management system 2001.

The first device 2021 may specifically be a smartphone, a tablet or any other mobile phone or mobile device that may generally be considered as the device that has a limited battery life time and would need connection to a current source for recharging.

The second device 2022 may be a device, with which the first device 2021 is or can be in a specific sidelink communication, such as the communication described in the 3GPP Standard of 4G or 5G. Among these different entities, vehicle-to-vehicle services (V2V) and vehicle-to- device services may be provided. This was already explained above in relation to figures 1 to 19 and is encompassed by the embodiments according to figure 20 and the following embodiments described in relation to figures 21 to 24.

The localization management system 2001, according to some embodiments of the present disclosure, may be adapted to “listen” to the sidelink communication 2030 established between the first device 2021 and the second device 2022. This “listening” to the communication may specifically be understood as not pertaining to or not encompassing the actual obtaining of messages (and their content) exchanged between the first device 2021 and the second device

2022. Rather, the “listening” may be understood to refer to the receiving of electromagnetic signals, for example, at the RAN-node 2012 of the localization management system 2001, which are associated with the sidelink communication 2030 between the first device 2021 and the second device 2022.

Specifically, the first device 2021 may send a first signal in an omnidirectional mode that will not only be received at the second device 2022, but also at the localization management system 2001 (for example, at the RAN-node 2012). Correspondingly, a second signal sent from the second device 2022 preferably in an omnidirectional manner, will be received not only at the first device 2021, but also at the localization management system 2001 and may specifically be received at the RAN-node.

The localization management system 2001 may, in some embodiments, be adapted to respond to the positioning request of the requesting entity 2023 with the localization information and specifically a position of the first device 2021 , wherein the position of the first device 2021 is, according to some embodiments, obtained via the correlation information that is obtained based on the sidelink communication between the first device 2021 and the second device 2022 and by using the position of the second device 2022 as far as it is available.

Specifically, the localization management system 2001, according to one embodiment, may determine whether there is a high correlation between the location of the first device 2021 and the location of the second device 2022. The localization management system 2001 may update the position of the first device 2021 as being equal to or associated with the position of the first device 2021.

This updated position may then be included or form the basis for at least part of a response that the localization management system 2001 sends in response to the requesting entity

2023. For example, the response may include the updated position of the first device 2021 and may be sent to the requesting entity 2023 in response to the positioning request.

Though the first device 2021, the second device 2022 and the requesting entity 2023 have been described in general terms, some embodiments may encompass that the first device 2021 is or comprises at least one of a mobile phone, a smartphone, a tablet or a laptop. Alternatively or additionally, the second device 2022 may be or may be part of a vehicle. The vehicle may, for example, be a car, a train or a bus. In the case of the second device 2022 being a car or a bus, the car or the bus may be driven by a combustion engine or by electric driving means, which also encompass the use of one or more batteries. In some embodiments, the available energy from the combustion engine and/or the batteries may be much larger in some embodiments compared to the capacity or available energy of the battery or the power source of the first device 2021.

Though not specified further, the requesting entity 2023 may be any entity that, for example, can provide services to the first device 2021 and/or the second device 2022 or any other devices. Thus, this requesting entity 2023 may, for example, be a server, a specifically dedicated computer or any other remote device that is different from the first device 2021 and the second device 2022, in some embodiments.

However, in some embodiments, the requesting entity 2023 may be the first device 2021 itself. In such a case, the first device 2021 may issue a positioning request to the localization management system 2001 because, if this request can be answered by the localization management system 2001 without the first device 2021 having to determine its position on its own, this may be more efficient with respect to the battery consumption at the first device.

In this respect, Figure 21 discloses a flow diagram of a method for providing localization information of a first device 2021 that potentially participates in a sidelink communication with a second device 2022, as exemplarily depicted in relation to Figure 20 and also in relation to the above Figures 1 to 19. All embodiments described in relation to Figure 21 are intended to be combinable with all embodiments described in relation to Figures 1 to 20.

The method depicted in Figure 21 begins in Step 2101 with receiving, at the localization management system 2001, a positioning request from a requesting entity. This may be requesting entity 2023, as shown in Figure 20. In some more specific embodiments, the requesting entity may be identical to the first device 2021 , but it can also be any other entity that comprises software and/or hardware that issues a corresponding request to the localization management system 2001.

In case the localization management system is realized as comprising a localization management function, a radio access network node (RAN-node) and an access and mobility management function (AMF), it may be provided that the AMF receives the positioning request, and upon that communicates with the LMF and/or the RAN-node for performing the further processing of this positioning request until finally a response can be provided to the requesting entity. Specifically, either the LMF or the RAN-node or both may process information on the sidelink communication to obtain correlation information and update, based on the correlation information, the position of the first device based on which the AMF may then send a response to the requesting entity. Proceeding further with the method in Figure 21, an optional step 2102 can be provided, according to which it may be determined by the localization management system whether the first device participates in sidelink communication at all.

Such a step may, in some embodiments, be advantageous, as the positioning request in step 2101 can generally be issued by a requesting entity regardless of whether or not the first device participates in sidelink communication at all and a response would have to be provided to the requesting entity. However, the advantages achieved with some of the embodiments according to the present disclosure are obtained when the first device participates in sidelink communication.

Therefore, at least for some embodiments, it may be advantageous to include an optional step of determining whether the first device participates in sidelink communication in line with step 2102. This may be done, for example, by analyzing or evaluating the signals received at one or more RAN-nodes of the localization management system, which may indicate that the first device participates in sidelink communication with a second device, and which, for example, may also allow for concluding which second device is participating in sidelink communication with the first device. From this, it may, for example, be possible to obtain an identification of both the first and the second device participating in the sidelink communication or an identification of at least one of these devices.

If it is determined in the step 2102 that the first device does not participate in sidelink communication with a second device, a method may be performed in step 2109 to determine the position of the first device. This may, for example, encompass determining by the first device itself its position using, for example, data from GPS satellites or GLONAS satellites or any other satellites that allow for determining the position of a device using one or more timing signals of the respective satellites.

Specifically, as part of determining the position of the first device in step 2109, the first device may perform a reference signal time difference measurement to determine its own position. Having done so, the first device may provide to the localization management system the determined position of the first device and the localization management system may send, as part of the step 2108, a response to the requesting entity with the corresponding localization information, which may, for example, include the position of the first device.

In case the requesting entity is the first device itself, this process may also be shortened by, for example, determining, in response to determining in step 2102 that the first device does not participate in sidelink communication with the second device, that a response from the localization management system including the localization information is not necessary, but the respective information is obtained by the first device itself during step 2109. In such a case, the sending of the position of the first device to the localization management system and the sending of a corresponding response to the first device from the localization management system can be omitted. Thereby, energy can be saved, since after having determined the position by the first device itself, no further exchange with the localization management system is necessary.

Returning again to Figure 21, the further process upon determining in the optional step 2102 that the first device participates in sidelink communication will be explained. It is noted that the step 2102 could also be omitted and the method would immediately proceed from this step 2101 to the step 2103, which is described in the following.

In the step 2103, correlation information may be obtained by the localization management system. This correlation information may be information or may comprise information or indicator that is indicative of a correlation between the location or position of the first device and the location or position of the second device. A location correlation may thus, for example, pertain to or provide information on whether the first device is in close proximity to the second device, with which it is in sidelink communication and/or moves together with the second device.

Example location correlations may thus be separated into three cases.

In one case of location correlation, the first device moves together with the second device (for example, a smartphone that is carried by a driver of a car, who is driving through the environment). In such a case, there is a strong correlation between the location of the second device and the location of the first device. Strong correlation may, for example, indicate that the position of the first device can be considered as being identical to the position of the second device or the first device being, also over longer periods of time, in close proximity to the second device.

In a second case, the first device and the second device may move with identical speed, but have comparably distance. This may pertain to cases where the first device is carried by a user driving with a car that is comparably far away from the car with which the first device is in sidelink communication with the second device. In some cases, while there may be some correlation between the location of the first and the location of the second device, the degree of correlation may be too weak to justify assuming that the position of the first device could be set to be equal to or associated with the position of the second device. In a third case, even though the first device and the second device may, at a given point in time, be in close proximity to each other, they move with different velocities. For example, this may be the case if a pedestrian carrying the first device (for example, a smartphone) stands close to a street or walks close to a street, along which a car as second device is driving. In such cases, for a short period of time, the position of the first device and the position of the second device may almost be identical. However, as they may move at all times or at least for a period of time with different velocities, the position of the first devices changes in a way that is independent from the position of the second device. This case may thus be considered to not allow for assuming that the position of the first device is somehow correlated with the position of the second device.

The three cases and the extent to which some or more of these cases are realized can be included in the correlation information. This may be done, for example, by providing a correlation value that indicates a degree of correlation between the location of the first device and the location of the second device as part of the correlation information. The correlation value may, for example, range from 0 to 1 , where 0 indicates a degree of correlation that is lower compared to the degree of correlation with value 1. For example, the correlation value 0 may indicate no correlation at all which may be understood to mean that the position of the first device is independent from the position of the second device, whereas the correlation value 1 may indicate high or perfect correlation which may be understood to mean that the position of the first device is, at all times, the same as the position of the second device.

Additionally, the correlation information may include identifications of the first device and/or the second device. These may be obtained for example during the optional step 2102. Furthermore, signal powers associated with a sidelink communication of the first device and/or the second device or any values derived therefrom (for example, mean values or square mean values or any other reasonable values) may be included in the correlation information and could, for example, be used for further processing.

Moreover, the correlation information may comprise a value that is derived from the first signal and the second signal or specifically a first signal power associated with a sidelink communication signal of the first device and a second signal power associated with a sidelink communication signal of the second device. Instead or in addition, the correlation information may also include an indication of a degree of correlation, wherein this indication may, for example, range between values from 0 to 1 , where 0 may indicate that there is no correlation between the location of the first device and the second device, and a value of 1 indicates high or exact correlation between the position of the first device and the position of the second device. Moreover, the correlation information may include an (explicit) indication that the position of the first device is equal to or associated with the position of the second device. Such an indication can, for example, be advantageously provided in case the correlation information is obtained by the RAN-node. In such a case, the correlation information will be sent from the RAN-node to the LMF, and it may be computationally efficient to include, in such a case, in the correlation information a value that is indicative of whether there is a high degree of correlation and therefore the position of the first device is equal to or associated with the position of the second device. This is because based on this information (which might be a binary information, wherein a first value, for example, 0, indicates that the position of the first device is not equal to or associated with the position of the second device and a second value, for example, 1 , indicates that the position of the first device is equal to or associated with the position of the second device), the LMF can determine, with reduced processing, whether or not the position of the first device is to be updated as equal to or associated to the position of the second device.

Additionally or alternatively, the correlation information may include a first value associated with the sidelink communication signal of the first device, a second value associated with the sidelink communication signal of the second device, or a value derived from a time series of values associated with the sidelink communication signal of the first device or a corresponding value derived from a time series of values associated with the sidelink communication signal of the second device.

This includes, for example, standard deviations of the signal power received at an RAN-node for both the first sidelink communication signal and the second sidelink communication signal. Likewise, a median signal power of the first signal and/or the second signal or a calculation of third quantiles or a fast Fourier transformation of the first signal and/or the second signal associated with the first device and/or the second device may be included in the correlation information.

After obtaining this correlation information, it may be determined in a subsequent optional step 2104 whether the position of the second device that participates in the sidelink communication with the first device is available at the localization management system. This optional step can also be performed at another position within the flow diagram. For example, this determination may be done during obtaining of the correlation information or in parallel to this step 2103. Alternatively, this optional step 2104 may be performed before obtaining correlation information and after receiving the positioning request. More specifically, this step 2104 can be part of the optional step 2102, if provided. Returning to step 2104, this step may comprise determining whether the LMF has information that pertains to or indicates the position of the second device. If it is determined in the optional step 2104 that the position of the second device is not available, it may either be proceeded with the method of determining the position of the first device in line with step 2109, as already indicated above. Alternatively, a method for determining the position of the second device may be performed in step 2110.

For example, in some embodiments, the position of the second device is determined periodically. In such a case, an almost accurate or sufficiently accurate position of the second device will usually be available, while the method according to Figure 21 is performed. In such a case, no further determination of the position of the second device may be necessary.

However, in other cases, it may be provided that the position of the second device is only determined in response to receiving a positioning request in line with step 2101. In such a case, in response to determining that the position of the second device is not available in step 2104, the step 2110 may be performed so as to determine the position of the second device. This may be done in the same way as the position of the first device would be determined in line with step 2109.

Irrespective of whether step 2110 is performed or whether it is determined in step 2104 that the position of the second device is available to the localization management system, the method proceeds with step 2105. This comprises an updating of the position of the first device based on the correlation information by also using, in some embodiments, the position of the second device.

This “updating” of the position of the first device is to be understood as not only encompassing cases wherein the most recent position of the first device is updated in the sense that a new position is used for the first device or this new position is replacing this most recent position of the first device. Furthermore, also cases are encompassed, in which the position of the first device is previously unknown and the “updating” of the position thus encompasses the setting of the position of the first device for the first time.

The updating of the position of the first device based on the correlation information may be performed in two ways. In the first case, according to step 2106, the position of the first device may be updated as equal to or associated with the position of the second device. This requires that the position of the second device is available.

In some embodiments, the step 2106 may be performed only if the correlation information indicates that there is a high correlation between the position of the first device and the position of the second device (corresponding, for example, to the case in which the first device is a smartphone that is carried by a user driving in a car, which constitutes the second device).

In the other case, in which the correlation information indicates that there is no sufficient or no correlation at all between the location of the first device and the location of the second device, in step 2107, the position of the first device itself may be determined. This may be done in a way identical to the way in which the position of the first device would be determined according to step 2109.

Having updated the position of the first device either along step 2106 or by means of the step 2107, the method proceeds with the method of the step 2108 by sending a response to the requesting entity, where this response is based on the updated position of the first device. For example, the response may include the updated position of the first device or information derived therefrom.

Figure 22 shows a more specific embodiment of the general method described in relation to Figure 21.

According to this embodiment, the localization management system comprises a localization management function and a RAN-node, which may, in some embodiments, be a NG-RAN node. The localization management system may further comprise an access and mobility management function AMF, as described above, which receives all connection and session related information from the user equipment (like the first device) and may also receive, for example, the positioning request as was already explained above. However, this is of no relevance to the procedure described in relation to Figure 22, but the Figure 22 pertains to the case in which the correlation information is obtained at the RAN-node and is provided to the localization management function LMF.

In view of this, the method begins with the step 2201, in which the positioning request is received at the localization management system. This step may be identical to the step 2101 and may, for example, encompass that the positioning request is received at the AMF or is generally received at the localization management system. In a further optional step 2202, it may be determined (corresponding to the step 2102) whether the first device participates in sidelink communication with a second device. This may optionally comprise determining the second device with which the first device participates in sidelink communication.

If it is determined in the optional step 2102 that the first device does not participate in sidelink communication with any second device, the method may proceed with the step 2211 for performing a method for determining the position of the first device in line with the embodiment described above in relation to step 2109 in the embodiment of Figure 21.

After that and after determining the position of the first device, the method may proceed with the step 2209, which comprises sending a response to the requesting entity based on the position of the first device, which may, for example, also comprise the position determined for the first device. All further explanations and embodiments mentioned with respect to the order of steps 2211 and 2209 corresponding to the steps 2109 and 2108 in Figure 21 are also valid for the embodiments described in relation to Figure 22.

The method proceeds, either if it is determined in step 2202 that the first device participates in sidelink communication with a second device or if this step is not present, with the step 2203, according to which correlation information is obtained at the RAN-node. In this embodiment, the correlation information that is obtained in the RAN-node may be, in its general meaning, correlation information that allows, when being received by the LMF, to determine whether the position of the first device can be updated as equal to or associated with the position of the second device.

Therefore, in some embodiments, it is preferred if the RAN-node obtains, for example, from a first signal power associated with a sidelink communication signal of the first device or a value derived from the first signal power and/or a second signal power associated with a sidelink communication signal of the second device or a value derived therefrom, an indication of a degree of correlation of the location of the first device and the location of the second device. This indication may, for example, be a value ranging from 0 to 1 , wherein 0 indicates low or no correlation of the location of the first device with the location of the second device at all, whereas a value of 1 indicates perfect or almost perfect or at least high correlation of the location of the first device and the location of the second device.

In an alternative embodiment, the correlation information obtained by the RAN node may be or may comprise an indication or indicator that the position of the first device is equal to or associated with the position of the second device. This can be performed, for example, by using binary values, wherein a value of 0 indicates that the position of the first device is not equal to or associated with the position of the second device, and a value of 1 indicates that the position of the first device is or can be considered equal to or associated with the position of the second device.

The indication or indicator that the position of the first device is equal to or associated with the position of the second device or the indication or indicator of the degree of the correlation may be obtained by the RAN-node using information associated with the sidelink communication between the first device and the second device.

For example, as mentioned above, an identification of the first device and/or an identification of the second device and/or a first signal power associated with the sidelink communication signal of the first device or a value derived therefrom and/or a second signal power associated with the sidelink communication signal of the second device or a value derived therefrom, or a value derived from the first signal power and the second signal power may be used to obtain the respective indications. For example, this may encompass determining or calculating a first variance associated with the sidelink communication signal, and specifically the first signal power of the first device at the RAN-node and/or a second variance associated with the sidelink communication signal of the second device or the second signal power of the sidelink communication signal of the second device at the RAN-node.

Specifically, for obtaining, in one embodiment, information indicative of the correlation of the position of the first device and the position of the second device, correlation coefficients of variance vectors associated with the signal power of the first device and the signal power of the second device may be calculated by

where m_A and s_A are the mean and standard deviation of the variance vector A = (A_lr ... A ... , A_n) (for example of the first device), respectively, and m_B and s_B are the mean and standard deviation of the variance vector B = (B_lr

...,¾) (for example of the second device). The value p(A,B) is larger the more the signals and thus the positions of the first device and the second device are.

All of the above values may be obtained by evaluating the first signal power and the second signal power over a time period of, for example, 1s, 2s, 0,5s, 10s or the like.

Correspondingly, also the values derived from a time series of a value associated with the sidelink communication of the first and/or the second device (for example, the first signal power or the second signal power) may be used to determine the indications.

For example, instead of the above equation, a median value or a fast Fourier transformation of both the first signal power and the second signal power may be used to determine a correlation between the location of the first device and the location of the second device, and to derive therefrom an indication of a degree of correlation or an indication that the position of the first device is equal to or associated with the position of the second device. Having obtained this correlation information in Step 2203, this correlation information may be provided in step 2204 to the localization management function, LMF. This may be performed via a data connection between the LMF and the RAN node.

In step 2205, it may optionally be determined whether the position of the second device is available at the LMF. This step and the further steps 2211 and 2210 may correspond to the steps 2104, 2109 and 2110 in line with the embodiments described in relation to the Figure 21, and will thus not be repeated here.

In any case, if it is possible to obtain the position of the second device at the LMF, or the position of the second device is already available at the LMF, the method proceeds in step 2206 by updating, via the LMF, the position of the first device based on the correlation information.

Depending on the correlation information (whether it is determined that there is a high degree correlation or there is no correlation between the location of the first device and the second device), this may be performed either by updating the position of the first device as being equal to or associated to the position of the second device, in line with step 2207. This step essentially corresponds to the step 2106 and will thus not be repeated here.

Alternatively, if the correlation information indicates that the location of the first device is not correlated to the position of the second device, the step 2208 may be performed according to which the first device may be requested, by the localization management system, to determine the position of the first device. This may be done in a way that is in line with the explanations provided with respect to step 2107 in Figure 21.

Having thus obtained the position of the first device either by means of step 2207 or 2208, the method proceeds with sending a response to the requesting entity in line with step 2209.

The sending of the response may correspond to the sending of the response explained in step 2108 in Figure 21. Specifically, this may encompass that the LMF sends the position or the updated position of the first device to the AMF, which in turn, sends the response to the requesting entity based on the localization information.

Figure 23 shows a further flow diagram according to an alternative embodiment of the invention, wherein the correlation information is obtained at the localization management system. The method begins with step 2301 comprising receiving a positioning request at the localization management system. This positioning request originates from a requesting entity, such as the requesting entity explained in relation to Figure 20. After that, an optional step 2302 may be provided once again that comprises determining whether the first device participates in a sidelink communication with a second device. This may be performed in the same way as described in relation to Figures 21 and 22, respectively.

If it is determined that the first device does not participate in a sidelink communication at all in the step 2302, the method may proceed with the step 2311 , in which a method is executed to determine the position of the first device.

The method then proceeds with the step 2310 comprising sending a response to the requesting entity based on the updated position of the first device, which may be the position of the first device determined in the step 2311. The details regarding this approach, which were explained above with respect to Figures 21 and 22 and are thus not repeated here, are explicitly intended to combine with the embodiment according to Figure 23.

Either in case it is determined in step 2302 that the first device participates in sidelink communication or in case this step is not provided, the method proceeds with step 2303, in which the RAN-node obtains at least one signal of either the first device or the second device, or both, or obtains information associated with at least one signal associated with the sidelink communication of the first device and/or the second device. As explained above with respect to Figure 20, for example, the RAN-node “listens” to the sidelink communication between the first device and the second device. It can therefore obtain the signals exchanged between the first device and the second device or derive or obtain information associated with the signals without having to know the actual content transmitted via the signals.

For example, the RAN node may obtain a signal strength associated with the first signal associated with sidelink communication of the first device or the second signal associated with the sidelink communication of the second device. The RAN-node can also obtain both signal powers.

The RAN node can then provide information on the signals to the LMF. This may either be the information the RAN-node actually obtained in the step 2303 or may comprise process information of the signals. For example, the RAN node may provide to the LMF the first signal power and/or the second signal power mentioned above. Alternatively or additionally, the RAN node may provide a value derived from the first signal power and/or the second signal power to the LMF or a value derived from the first signal power and the value derived from the second signal power, respectively.

Alternatively or additionally, the RAN node may obtain a variance associated with the sidelink communication signal of the first device and/or a variance associated with the sidelink communication signal of the second device, and/or a value derived from these variances. These values or variances may be provided to the LMF.

After providing the information on the signals to the LMF, the LMF may then determine whether a position of the second device is available at the LMF in the optional step 2305. The further procedure in the step 2311, if it is determined that the position of the second device is not available at the LMF, corresponds to what was described above in relation to the steps 2211 and 2109 in Figures 22 and 21, respectively. The alternative approach, wherein the position of the second device is not available at the LMF, but can be determined, for example upon having received a corresponding positioning request in step 2312, corresponds to what was already described in relation to the steps 2210 and 2110 in Figures 22 and 21, respectively. These embodiments are not repeated here.

Having obtained the position of the second device, the method of Figure 23 may proceed with the step 2306 of obtaining the correlation information at the LMF. The way in which the correlation information is obtained may depend on what information was provided to the LMF by the RAN-node in the step 2304.

For example, if the signal powers of the first signal and the second signal were provided to the LMF by the RAN-node, the LMF may derive the correlation values from the signal powers and may determine a variance associated with the sidelink communication signal of the first device and a second variance associated with the sidelink communication signal of the second device, and may derive therefrom, a value or an indication that is indicative of the degree of correlation between the location of the first device and the second device. This may, for example, be a number within the range of 0 to 1, wherein 0 corresponds to no correlation and 1 corresponds to exact or full or high correlation. The correlation may be determined using equation (1) as referred to above.

The LMF can then, in some embodiments, compare the obtained indication or value to a threshold, and, if the value or indication exceeds the respective threshold, the LMF can assume that there is correlation between the location of the first device and the second device to such an extend that the position of the first device can be set as equal to or associated to the position of the second device.

For example, if a value p = 0,7 is obtained in one case and a threshold value p_thresuoi_d = 0-95, the LMF may conclude that the actual correlation value is smaller than the threshold and thus the correlation between the position of the first device and the position of the second device does not qualify to update the position of the first device as equal to or associated to the position of the second device. In case, for example, p = 0,97, this value can be determined to exceed the threshold value and the LMF can determine that the correlation between the position of the first device and the position of the second device qualifies to update the position of the first device as equal to or associated to the position of the second device.

This can be performed during the step 2307, where the position of the first device is updated based on the correlation information. If the correlation information indicates that the location of the first device and the location of the second device correlate with each other, and the position of the second device is available at the LMF, then the method can proceed in step 2308 with updating the position of the first device as being equal to or associated with the position of the second device.

This updated position can then be used to provide a response to the requesting entity in step 2310, wherein the response may comprise or may at least be based on the updated position of the first device as being equal to or associated to the position of the second device. For example, the response to the requesting entity may comprise the updated position of the first device.

In case it is determined in step 2307 that the position of the first device does not correlate with or is not correlated with the location of the second device, then the method can proceed in step 2309 with determining the position of the first device, for example, in line with the determination of the position of the first device in step 2311. This may comprise requesting the first device to perform a reference signal time difference measurement to obtain its position. Once this position is obtained, the obtained position or information associated with or based on the obtained position can be provided by the first device to the LMF, which in response to the positioning request, send a response to the requesting entity in step 2310, based on the position of the first device determined in step 2309.

Extending the concepts discussed in relation to Figures 21 to 23, Figure 24 discusses a further special case where, even though it is determined with any of the methods described in relation to Figures 21 to 23, that there is a correlation between the position of the first device and the position of the second device, the position of the second device is not available to the localization management system (for example the LMF) and, thus, updating the position of the first device as equal to the second device cannot be performed.

The method shown in Figure 24 may follow the steps 2104, 2205 or 2305, according to which it is determined, for example at the LMF, whether the position of the second device is available.

If the position of the second device is available, the methods described in relation to Figures 21 to 23 can proceed in the way as already described above. If the position of the second device is not available, the position of the first device has to be determined, as was also already described above.

This is shown in Figure 24 in step 2403. Any of the above described methods for obtaining localization information and/or the position of the first device can be employed in this step.

It may be provided that, before performing step 2403, the method comprises obtaining the correlation information in step 2402, as was also already described above. The step 2402 can, however, also be performed after the step 2403 or it can be performed before the step 2401 during which it is determined whether the position of the second device is available.

Once the correlation information and the position of the first device is obtained, the method can proceed in step 2404 with updating the position of the second device based on the correlation information. This may encompass updating the position of the second device as equal to or associated with the position of the first device (for which the position has been determined in step 2403) if the correlation information for example indicates that there is high correlation of the position of the first device and the position of the second device, as is indicated with step 2405. If the correlation information indicates that the correlation of the position of the first device is not sufficient to set the position of the second device equal to or associated with the position of the first device (for example because a correlation value of provided in the correlation information is below a given threshold), then the method may proceed to step 2407 where an updating of the position of the second device is not performed or is at least not done in a way so as to set the position of the second device equal to or associated to the position of the first device.

After the position of the second device has been updated in steps 2405 to 2407 or in parallel to these steps or before these steps, for example in response to having performed the step 2403, a response to the requesting entity may be sent based on the obtained localization information, as was already described in relation to Figures 21 to 23.

Figure 25 illustrates a schematic depiction of a localization management system according to one embodiment.

The localization management system 2500 in this embodiment comprises one or more computing entities 2501 , a receiver 2502 and a transmitter 2503. It is understood that the receiver 2502 and the transmitter 2503 can also be provided as an integrated device in the form of a transceiver not separately depicted here. Such a transceiver, when implemented, for example, as hardware is adapted to realize both the functionalities of a receiver and a transmitter. The one or more computing entities 2501 may be realized, for example, as one or more processors having associated therewith a corresponding storage in some embodiments.

According to some embodiments, the receiver 2502 can receive a positioning request for the first device from a requesting entity not shown in Figure 25. The requesting entity was explained above in relation to Figure 20 and the embodiments described in relation this requesting entity are considered applicable also to Figure 25.

The one or more computing entities 2501 can obtain correlation information, wherein the correlation information is indicative of the location correlation between the first device and the second device based on the sidelink communication between the first device and the second device. The one or more computing entities 2501 may optionally be able to determine, before obtaining the correlation information, whether the first device and the second device are participating in a sidelink communication. This may comprises determining the second device that participates in the sidelink communication with the first device and may optionally comprise obtaining identifications of the first device and/or the second device.

The one or more computing entities 2501 can further update a position of the first device as being equal to or associated with the position of the second device based on the correlation information. How this can be performed was explained above in further detail with respect to Figures 21 to 24 and is not repeated here.

The transmitter 2503 can send a response to the requesting entity in response to the positioning request based on the updated position of the first device. As explained above in further detail, this response may comprise the updated position of the first device or may at least be based on this updated position.

The localization management system according to the embodiments explained above in relation to Figure 25 is suitable for carrying out any of the methods described in relation to the above figures.

While the above disclosure refer to components, such as computing entities, receivers and transmitters, it is understood that each of these components or combinations thereof may be implemented by specifically dedicated hardware and/or specifically adapted software to perform the necessary functions. The software includes programming that may, for example, be provided in one or more dedicated storages that can be executed by at least the one or more computing entities explained above in relation to Figure 25.

Claims

1. A method for providing localization information of a first device that participates in a sidelink communication with a second device, the method comprising: receiving, at a localization management system, a positioning request for the first device from a requesting entity; obtaining, at the localization management system, correlation information, wherein the correlation information indicative of location correlation between the first device and the second device based on sidelink communication; updating, at the localization management system, a position of the first device as equal to or associated to a position of the second device based on the correlation information; sending, by the localization management system, a response to the requesting entity based on the updated position of the first device.

2. The method according to claim 1 , wherein the position of the second device is obtained by the localization management system upon receiving the positioning request, or wherein the position of the second device is periodically obtained by the localization management system.

3. The method according to claim 1 or 2, wherein, after receiving the positioning request and before obtaining the correlation information, the localization management system determines whether the first device is participating in a sidelink communication, comprising determining the second device with which the first device participates in the sidelink communication.

4. The method according to any of claims 1 to 3, wherein the correlation information is obtained from a first signal associated with a sidelink communication signal of the first device and a second signal associated with a sidelink communication signal of the second device.

5. The method according to any of claims 1 to 4, wherein the correlation information is obtained from a correlation coefficient and the correlation coefficient is obtained from a first variance associated with a sidelink communication signal of the first device and a second variance associated with a sidelink communication signal of the second device.

6. The method according to any of claims 1 to 5, wherein the correlation information comprises at least one of: a correlation value, an identification of the first device, an identification of the second device, a first signal power associated with a sidelink communication signal of the first device or a value derived from the first signal power, a second signal power associated with a sidelink communication signal of the second device or a value derived therefrom, a value derived from the first signal power and the second signal power, an indication of a degree of correlation, an indication that the position of the first device is equal to or associated with the position of the second device, a first variance associated with the sidelink communication signal of the first device, a second variance associated with the sidelink communication signal of the second device, a value derived from a time series of a value associated with the sidelink communication signal of the first device, a value derived from a time series of a value associated with the sidelink communication signal of the second device .

7. The method according to any of claims 1 to 6, wherein the localization management system comprises a RAN node and/or a location management function, LMF, and/or an access and mobility management function, AMF.

8. The method according to any of claims 1 to 7, wherein, the correlation information comprises a correlation value and the method further comprises determining if the correlation value is larger than or equal to a threshold and, if it is determined that the correlation value is not larger than or equal to the threshold, the localization management system requests the first device to perform a reference signal time difference measurement.

9. The method according to any of claims 1 to 8, wherein the first device is or comprises at least one of a mobile phone, a smart phone, a tablet, a laptop; and/or wherein the second device is or is part of a vehicle, wherein the vehicle optionally is at least one of a car, a train, a bus; and/or wherein the requesting entity is the first device or a third device that is different from the first device and the second device.

10. A localization management system comprising one or more computing entities, a receiver and a transmitter, wherein: the receiver can receive a positioning request for the first device from a requesting entity; the one or more computing entities can obtain correlation information, wherein the correlation information is indicative of location correlation between the first device and the second device based on sidelink communication; the one or more computing entities can update a position of the first device as equal to or associated to a position of the second device based on the correlation information; the transmitter can send a response to the requesting entity based on the updated position of the first device.

11. The localization management system according to claim 10, wherein the one or more computing entities can obtain the position of the second device upon receiving the positioning request, or wherein the one or more computing entities can obtain the position of the second device periodically.

12. The localization management system according to claim 10 or 11, wherein the one or more computing entities can determine, after receiving the positioning request and before obtaining the correlation information, whether the first device is participating in a sidelink communication, comprising determining the second device with which the first device participates in the sidelink communication.

13. The localization management system according to any of claims 10 to 12, wherein the one or more computing entities can obtain the correlation information from a first signal associated with a sidelink communication signal of the first device and a second signal associated with a sidelink communication signal of the second device.

14. The localization management system according to any of claims 10 to 13, wherein the one or more computing entities can obtain the correlation information from a correlation coefficient and/or can obtain the correlation coefficient from a first variance associated with a sidelink communication signal of the first device and a second variance associated with a sidelink communication signal of the second device.

15. The localization management system according to any of claims 10 to 14, wherein the correlation information comprises at least one of: a correlation value, an identification of the first device, an identification of the second device, a first signal power associated with a sidelink communication signal of the first device or a value derived from the first signal power, a second signal power associated with a sidelink communication signal of the second device or a value derived therefrom, a value derived from the first signal power and the second signal power, an indication of a degree of correlation, an indication that the position of the first device is equal to or associated with the position of the second device, a first variance associated with the sidelink communication signal of the first device, a second variance associated with the sidelink communication signal of the second device, a value derived from a time series of a value associated with the sidelink communication signal of the first device, a value derived from a time series of a value associated with the sidelink communication signal of the second device.

16. The localization management system according to any of claims 10 to 15, wherein the localization management system comprises a RAN node and/or a location management function, LMF, and/or an access and mobility management function, AMF.

17. The localization management system according to any of claims 10 to 16, wherein, the correlation information comprises a correlation value and the one or more computing entities can determine if the correlation value is larger than or equal to a threshold and can request, if it is determined that the correlation value is not larger than or equal to the threshold, the first device to perform a reference signal time difference measurement.

18. The localization management system according to any of claims 10 to 17, wherein the first device is or comprises at least one of a mobile phone, a smart phone, a tablet, a laptop; and/or wherein the second device is or is part of a vehicle, wherein the vehicle optionally is at least one of a car, a train, a bus; and/or wherein the requesting entity is the first device or a third device that is different from the first device and the second device.

19. A computer-readable storage medium comprising computer-executable instructions that, when executed by a localization management system comprising one or more computing entities, a receiver and a transmitter, cause the localization management system to perform a method according to any of claims 1 to 9.