Sidelink synchronization during user device selection

Abstract

The present disclosure relates to systems, methods, apparatus, and computer program products for sidelink (SL) synchronization during user equipment (UE) selection. The method may include receiving one or more messages from one or more devices in a selected device set. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. The method may also include selecting at least one device in the selected device set for a positioning communication session based on the synchronization information. The method may further include performing a position estimation for the device based on a positioning signal received through the positioning communication session from the at least one device in the selected device set.

Description

Technical Field

[0001] Some exemplary embodiments may generally relate to mobile or wireless telecommunications systems such as Long Term Evolution (LTE) or 5th Generation (5G) New Radio (NR) access technologies, or 5G Beyond, or other communication systems. For example, certain exemplary embodiments may relate to an apparatus, system, and / or method for sidelink (SL) synchronization during user equipment (UE) selection.

Background Art

[0002] Examples of mobile or wireless telecommunications systems may include Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), LTE Evolved UTRAN (E-UTRAN), LTE Advanced (LTE-A), MulteFire, LTE-A Pro, and / or 5th Generation (5G) radio access technology or NR access technology. The 5G wireless system refers to the next generation (NG) wireless system and network architecture. 5G network technology is mainly based on New Radio (NR) technology, but the 5G (or NG) network can also be based on E-UTRAN radio. NR is expected to provide bitrates of about 10 - 20 Gbit / s or more and support at least enhanced mobile broadband (eMBB), and ultra-reliable low-latency communication (URLLC), as well as massive machine type communication (mMTC). NR is expected to provide extremely wideband and ultra-robust low-latency connectivity and large-scale networking for supporting the Internet of Things (IoT).

Summary of the Invention

Means for Solving the Problems

[0003] Several exemplary embodiments can be directed to a method. The method may include receiving one or more messages from one or more devices in a selected set of devices. According to a particular exemplary embodiment, each of the one or more messages may include synchronization information. The method may also include selecting at least one device in the selected set of devices for a positioning communication session based on the synchronization information. The method may further include performing a position estimation of the device based on a positioning signal received through the positioning communication session from at least one device in the selected set of devices.

[0004] Other exemplary embodiments may be directed to the apparatus. The apparatus may include at least one processor and at least one memory containing computer program code. The at least one memory and computer program code may also be configured to cause the apparatus, using at least one processor, to receive one or more messages from at least one or more devices in a selected set of devices. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. Based on the synchronization information, the apparatus may be caused to select at least one device in the selected set of devices for a positioning communication session. The apparatus may further be caused to perform position estimation of the apparatus based on positioning signals received through the positioning communication session from at least one device in the selected set of devices.

[0005] Other exemplary embodiments may be directed to the apparatus. The apparatus may include means for receiving one or more messages from one or more devices in a selected set of devices. According to a particular exemplary embodiment, each of the one or more messages includes synchronization information. The apparatus may also include means for selecting at least one device in the selected set of devices for a positioning communication session based on the synchronization information. The apparatus may further include means for performing position estimation of the apparatus based on positioning signals received through the positioning communication session from at least one device in the selected set of devices.

[0006] According to other exemplary embodiments, instructions capable of performing a method executed in hardware can be encoded on a non-temporary computer-readable medium. The method may include receiving one or more messages from one or more devices in a selected set of devices. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. The method may also include selecting at least one device in the selected set of devices for a positioning communication session based on the synchronization information. The method may further include performing a position estimation of the device based on a positioning signal received through the positioning communication session from at least one device in the selected set of devices.

[0007] Other exemplary embodiments may be directed to a computer program product that implements the method. The method may include receiving one or more messages from one or more devices in a selected set of devices. According to a particular exemplary embodiment, each of the one or more messages may include synchronization information. The method may also include selecting at least one device in the selected set of devices for a positioning communication session based on the synchronization information. The method may further include performing a position estimation of the device based on a positioning signal received through the positioning communication session from at least one device in the selected set of devices.

[0008] Other exemplary embodiments may be directed to a device that may include a circuit configured to receive one or more messages from one or more devices in a selected set of devices. According to a particular exemplary embodiment, each of the one or more messages may include synchronization information. The device may also include a circuit configured to select at least one device in the selected set of devices for a positioning communication session based on the synchronization information. The device may further include a circuit configured to perform position estimation of the device based on positioning signals received through the positioning communication session from at least one device in the selected set of devices.

[0009] Several exemplary embodiments can be directed to a method. The method may include receiving a request from a device for synchronization information. The method may also include performing a synchronization status evaluation using one or more devices in a set of devices in accordance with the received request. The method may further include sending one or more messages to that device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. In addition, the method may also include receiving a positioning session establishment request based on the synchronization information. Furthermore, the method may include performing positioning with that device in response to the positioning establishment request.

[0010] Other exemplary embodiments may be directed to a device. The device may include at least one processor and at least one memory containing computer program code. The at least one memory and computer program code may also be configured, using at least one processor, to cause the device to receive at least a request for synchronization information from a device. The device may also be caused to perform a synchronization status evaluation using one or more devices in a set of devices in accordance with the received request. The device may further be caused to send one or more messages to that device based on the synchronization status evaluation. According to a particular exemplary embodiment, each of the one or more messages may contain synchronization information. In addition, the device may be caused to receive a positioning session establishment request based on the synchronization information. Furthermore, the device may be caused to perform positioning with that device in response to the positioning establishment request.

[0011] Other exemplary embodiments may be directed to a device. The device may include means for receiving a request for synchronization information from a device. The device may also include means for performing a synchronization status evaluation using one or more devices in a set of devices in accordance with the received request. The device may further include means for sending one or more messages to the device based on the synchronization status evaluation. According to a particular exemplary embodiment, each of the one or more messages may include synchronization information. In addition, the device may also include means for receiving a positioning session establishment request based on the synchronization information. Furthermore, the device may include means for performing positioning with the device in response to the positioning establishment request.

[0012] According to other exemplary embodiments, instructions capable of performing a method executed in hardware can be encoded on a non-temporary computer-readable medium. The method may include receiving a request from a device for synchronization information. The method may also include performing a synchronization status evaluation using one or more devices in a set of devices in accordance with the received request. The method may further include sending one or more messages to that device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. In addition, the method may also include receiving a positioning session establishment request based on the synchronization information. Furthermore, the method may include performing positioning with that device in response to the positioning establishment request.

[0013] Other exemplary embodiments may be directed to a computer program product that implements the method. The method may include receiving a request from a device for synchronization information. The method may also include performing a synchronization status evaluation using one or more devices in a set of devices in accordance with the received request. The method may further include sending one or more messages to that device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. In addition, the method may also include receiving a positioning session establishment request based on the synchronization information. Furthermore, the method may include performing positioning with that device in response to the positioning establishment request.

[0014] Other exemplary embodiments may be directed to an apparatus that may include a circuit configured to receive a request for synchronization information from a device. The apparatus may also include a circuit configured to perform a synchronization status evaluation using one or more devices in a set of devices in accordance with the received request. The apparatus may further include a circuit configured to send one or more messages to that device based on the synchronization status evaluation. According to a particular exemplary embodiment, each of the one or more messages may include synchronization information. In addition, the apparatus may also include a circuit configured to receive a positioning session establishment request based on the synchronization information. Furthermore, the apparatus may include a circuit configured to perform positioning with that device in response to the positioning establishment request.

[0015] Please refer to the attached drawings for a proper understanding of the exemplary embodiments. [Brief explanation of the drawing]

[0016] [Figure 1] This figure shows an exemplary side link (SL) positioning scenario. [Figure 2A]This figure shows an example of SL positioning similar to the Downlink Arrival Time Difference (DL-TDOA). [Figure 2B] This figure shows an example of SL positioning similar to the uplink TDOA (UL-TDOA). [Figure 3] This figure shows an example of priority groups for synchronous reference sources. [Figure 4A] This figure shows an example of a signal flow diagram for an SL positioning scenario according to a specific exemplary embodiment. [Figure 4B] This figure shows a continuation of the SL positioning scenario signal flow diagram of Figure 4A, according to a specific exemplary embodiment. [Figure 4C] This figure shows a further continuation of the SL positioning scenario signal flow diagram of Figure 4A, according to a specific exemplary embodiment. [Figure 5] This figure shows a further example of an SL positioning scenario signal flow diagram according to a specific exemplary embodiment. [Figure 6] This figure shows an exemplary flowchart of an SL positioning method according to a specific exemplary embodiment. [Figure 7] This figure shows a set of devices according to a specific exemplary embodiment. [Modes for carrying out the invention]

[0017] It will be readily apparent that the components of the particular exemplary embodiments described herein and shown in the figures can be arranged and designed in a wide variety of different configurations. The following is a detailed description of several exemplary embodiments of systems, methods, apparatus, and computer program products for SL synchronization during UE selection. For example, certain exemplary embodiments can be directed towards the consideration of SL synchronization during anchor UE selection.

[0018] In this specification, "at least one of the following <list of two or more elements>" and "at least one of <list of two or more elements>" and similar expressions (where the list of two or more elements is connected by "and" or "or") mean at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0019] The features, structures, or characteristics of the exemplary embodiments described throughout this specification can be combined in any suitable manner in one or more exemplary embodiments. For example, when phrases such as "a particular embodiment", "an exemplary embodiment", "some embodiments", or other similar expressions are used throughout this specification, it refers to the fact that the particular features, structures, or characteristics described in relation to one embodiment can be included in at least one embodiment. Therefore, when phrases such as "in a particular embodiment", "an exemplary embodiment", "in some embodiments", "in other embodiments", or other similar expressions appear throughout this specification, they do not necessarily refer to the same group of embodiments, and the described features, structures, or characteristics can be combined in any suitable manner in one or more exemplary embodiments. Additionally, throughout this specification, terms such as "cell", "gNB", "network", or other similar expressions can be used interchangeably. In addition, throughout this specification, terms such as "sync", "synchronization", "synchronicity", or other similar expressions can be used interchangeably.

[0020] In this specification, a target UE can refer to a UE to be positioned, and an anchor UE can refer to a UE that supports the positioning of the target UE (e.g., by transmitting and / or receiving positioning reference signals via the SL interface). The function of an anchor UE (i.e., an anchor node) may be similar to UL / DL-based positioning where a gNB acting as an anchor transmits / receives reference signals to / from the target UE for positioning. In addition, in this specification, an SL positioning reference signal (PRS) can refer to a reference signal transmitted via the SL for positioning purposes.

[0021] The SL PRS (pre)configuration can collectively refer to the (pre)configured parameters of the SL PRS, such as the time-frequency resources including the bandwidth and periodicity of the SL PRS, as well as direction-related parameters (e.g., beam direction, beam width, and number of beams). The SL PRS (pre)configuration can also refer to the (pre)configured parameters of the SL PRS, such as transmission power. Furthermore, coverage or partial coverage can be determined by the network (e.g., by a Location Management Function (LMF) or a gNB), and outside the coverage, it can be autonomously preconfigured and / or determined by the UE. Consideration of SL synchronization during anchor UE selection can involve a Road Side Unit (RSU) where a fixed infrastructure entity of the UE type or gNB type supports vehicle-to-everything V2X applications. Absolute positioning can refer to estimating the position of a UE in 2D / 3D geographical coordinates (e.g., latitude, longitude, altitude) within a coordinate system. In addition, relative positioning can refer to estimating the position relative to other network elements or relative to other UEs. Furthermore, ranging can refer to the determination of the distance between two UEs and / or the direction of one UE from another UE by direct device connection.

[0022] The technical specifications for the Third Generation Partnership Project (3GPP) consider SL positioning in cases such as V2X, public safety, and the Internet of Things (IIoT) for commercial and industrial applications. Furthermore, 3GPP considers scenarios and requirements for NR positioning use cases in in-coverage, partial-coverage, and out-of-coverage scenarios, focusing on V2X and public safety use cases. SA1 is developing 3GPP requirements for distance-based services and positioning accuracy requirements for IIoT use cases in out-of-coverage scenarios. Positioning requirements can be captured by key performance indicators (KPIs). KPIs may include, for example, horizontal accuracy and vertical accuracy, where vertical accuracy refers to accuracy at altitude, determining the floor in the case of indoor use cases and distinguishing overlapping tracks (e.g., bridges) in the case of road and rail use cases. The KPI may also include positioning service availability, which corresponds to the percentage of the quotient obtained by dividing the amount of time the positioning service provides the required location-related data within performance requirements by the amount of time the system is expected to provide positioning services according to specifications within the targeted service area. The KPI may further include positioning service delay, which corresponds to the time elapsed from the event that triggers the determination of location-related data until the location-related data becomes available at the system interface. In addition, the KPI may also include time to fix (TTFF), which corresponds to the amount of time elapsed from the event that first triggers the determination of location-related data until the location-related data becomes available at the positioning system interface. The KPI may also include update rate and energy consumption parameters.

[0023] Figure 1 shows an exemplary SL positioning scenario. SL positioning can be based on the transmission of SL-PRS by multiple anchor UEs 112-114 (or SL-PRS exchange between anchor UEs and target UEs) to be received by target UE 110, enabling the positioning of target UE 110 within the strict delay and accuracy requirements of the corresponding SL positioning session. For example, as shown in Figure 1, target UE 110 may be performing an SL positioning session (i.e., exchanging SL-PRS with at least two anchor UEs 112, 114 to determine the position of target UE 110). In Figure 1, anchor UEs 112, 114 can provide SL-PRS assistance (including SL-PRS) to target UE 110 so that target UE 110 can determine its position.

[0024] Figure 2(a) shows an example of DL-TDOA-like SL TDOA, and Figure 2(b) shows an example of UL-TDOA-like SL TDOA. The SL-TDOA technique is a positioning technique that does not require bidirectional SL PRS transmission between the transmitter and receiver. 3GPP supports two types of TDOA techniques, including, for example, DL-TDOA and UL-TDOA. SL-TDOA can be implemented using concepts and principles similar to DL-TDOA and UL-TDOA. In one exemplary embodiment, DL-TDOA and UL-TDOA can correspond to TDOA techniques type 1 and type 2, respectively. In DL-TDOA (technique type 1), as shown in Figure 2(a), the target UE210 can calculate the position of the target UE210 by estimating reference signal time difference (RSTD) measurements from SL positioning reference signals (212a-218a) transmitted by different anchor UEs (212-218). In UL-TDOA (Type 1), as shown in Figure 2(b), the target UE210 can transmit SL-PRS(212b-218b) to multiple anchor UE212-218s, and the anchor UE212-218s can measure the relative time of arrival (RTOA), similar to UL-TDOA (Type 2). This measurement can be reported to a position calculation entity (e.g., LMF230 or target UE210) for position estimation of the target UE210. Since both the DL-TDOA and UL-TDOA procedures can be based on TDOA measurements, both procedures may require high-precision time synchronization between the reference UE212-218s to obtain an accurate position estimation of the target UE210.

[0025] SL positioning may also involve SL transmissions planned within frames identified by a Direct Frame Number (DFN). The DFN allows a UE (e.g., any of 212-218) to synchronize its radio frame transmissions according to an SL timing reference 220. In an exemplary embodiment, UEs 212-218 can perform SL synchronization for the use of the same SL timing reference 220 for SL communication between neighboring UEs by synchronizing with the same reference (e.g., SL timing reference 220). In an exemplary embodiment, the reference 220 shown as the entire reference 220 in Figures 2(a) and 2(b) may include one or more of several sources 220a to 220c for the SyncRef, which include, for example, a Global Navigation Satellite System (GNSS) 220a, an NR cell (gNB) or EUTRAN cell (eNB) 220b, and a SyncRef UE 220c. In another exemplary embodiment, SyncRef UE220c may be any of the internal clocks (e.g., 212c-218c) of the anchor UE itself.

[0026] Figure 3 shows an example of a priority group for a sync reference source. As shown in Figure 3, the UE210 can select its SyncRef (e.g., 220) using different source priorities P0 to P6 (where P0 to P6 correspond to the highest priority to the lowest priority, respectively), depending on whether it is a GNSS-based 320a / 220a sync (GNSS as the highest priority) or a gNB / eNB-based 320b / 220b sync (gNB / eNB as the highest priority).

[0027] As described above (see also Figures 2(a) and 2(b) for illustration), in SL, UE212-218 can perform SL synchronization to use the same SL timing reference 220 for SL communication between neighboring UEs (e.g., 212-218) by synchronizing with the same reference source 220. If gNB / eNB320b / 220b or GNSS320a / 220a is not available as a synchronization reference source, UE (e.g., UE212) can perform SL synchronization by synchronizing with a SyncRef UE (e.g., UE214). However, during this procedure, synchronization errors may occur between UEs (212, 214) due to, for example, synchronization misalignments of the SyncRef (e.g., 220d, 220e) corresponding to each of the UEs (212, 214), the stability of the UE's own clock (e.g., UE clocks 212c, 214c), and / or UE implementation errors. Therefore, in SL positioning, it can be difficult to support and maintain a high level of synchronization between anchor UE212-218s, especially considering that anchor UE212-218s may be built using significantly lower-cost hardware / software equipment compared to gNBs (e.g., 220b). In addition, anchor UE212-218s may have lower processing power than gNB220b, and anchor UE212-218s may be randomly distributed mobile UEs without any backhaul connection support.

[0028] In TDOA-based SL positioning solutions, positioning accuracy depends on the synchronization lead between anchor UEs (e.g., 212, 214), where a 1 nsec timing difference can result in a positioning error of approximately 36 cm. Therefore, highly synchronized anchor UEs may be required to support the SL TDOA method and meet the accuracy requirements of SL positioning. However, as discussed above, not all anchor UEs 212-218 are always sufficiently synchronized. Consequently, if there is a synchronization mismatch between anchor UEs 212-218 during an SL positioning session, the positioning accuracy of the target UE 210 may be degraded. In light of the drawbacks described above, certain exemplary embodiments may provide a way to select / determine a pair of anchor UEs 212-218 synchronized to the desired level of precision so that the UE can perform high-precision SL positioning. That is, certain exemplary embodiments may include a solution for the target UE 210 in an SL positioning session that uses information about the synchronization accuracy between anchor UEs 212-218 to enable high-precision positioning.

[0029] According to certain exemplary embodiments, the first UE 210 (e.g., target UE) can be configured to perform specific actions with respect to anchor UEs 212-218, including, for example, the actions shown in Figures 4A-4C referenced herein. For the sake of simplicity and for illustrative purposes, elements described in Figure 2 may be used to illustrate the description in Figures 4A-4C, for example, UEs 210-218 in Figure 2 may correspond to UEs 410-418 in Figures 4A-4C. Similarly, elements 217, 219, and 220, although not explicitly shown in Figures 4A-4C, can be considered to exist functionally for illustrative and illustrative purposes.

[0030] For example, a first UE410 (e.g., a target UE) can select a set of second UE412-418 (e.g., one or more of anchors 1 through 4) as candidate anchor UEs for SL positioning (see, e.g., Figures 4A-4C, Operation 1). The first UE410 can also request synchronization (sync) status assistance information from at least one second UE412 (e.g., any or more of candidate anchor 1 UE, anchor 2 UE, anchor 3 UE, and / or anchor 4 UE) (see, e.g., Figures 4A-4C, Operation 2). According to a particular exemplary embodiment, the synchronization status assistance information may include at least one of various information elements (IEs). For example, an IE may include multiple types of synchronization status assistance information desired by the target UE410.

[0031] In some exemplary embodiments, the synchronization status assistance information type may be of type 1, which may include synchronization status information for one or more other UE414 (i.e., anchor 2 in Figures 4A-4C) that can be synchronized with a second UE412 (i.e., anchor 1) and have a synchronization accuracy within a specified synchronization accuracy threshold L1. In some exemplary embodiments, as shown in operation 2a, the synchronization accuracy threshold L1 may correspond to some real number (e.g., x0 nsec).

[0032] In certain exemplary embodiments, the synchronization accuracy threshold (L1) can be explicitly or implicitly indicated in a request (i.e., operation 1) sent by the first UE 410 to the second UE 412. Type 1 synchronization status information that the first UE 410 may request from the second UE 412 may include, for example, identifiers (IDs) of one or more synchronized UEs (and possibly several N synchronized UEs, in this case N=2 for UEs), IDs of one or more unsynchronized UEs (i.e., 217, 219 shown in Figure 2), and / or synchronization levels for other synchronized UEs 416-418 (e.g., anchors 3 and 4).

[0033] In other exemplary embodiments (e.g., operation 2c), the IE may include Type 2 synchronization status assistance information, which may include synchronization status information about synchronization level L2 (i.e., synchronization threshold) for one or more of the third UEs (e.g., UE412). In some exemplary embodiments, UE412 may be directed by the first UE410 to the remaining anchor UEs 414, 416, and 418 in the request (i.e., operation 1).

[0034] In further exemplary embodiments, the IE may include a type 3 information type, which may include information relating to the synchronization reference source of a second UE412 (i.e., Anchor 1 UE) or to the synchronization reference source of another UE (if available) that is synchronized together. In a particular exemplary embodiment, target UE410 may select one synchronization reference source 420 (similar to 220 in Figure 2) and a threshold, and request synchronization assistance information from any of the anchor UEs (e.g., any of the anchor UEs 412-418) that have the same synchronization reference source 220 and are within that threshold. In other exemplary embodiments, the request to the second UE412 may include information regarding the reliability of the synchronization (e.g., synchronization error variance). For example, the reliability of the synchronization may be between anchor UEs, between the anchor UE and the reference source, or between the anchor UE and another selected UE (potentially the anchor UE). The reliability of the synchronization ensures that the anchor UEs are synchronized with each other (for example, anchor 2, 3, anchor 1, 3, anchor 1, 2), regardless of whether the target UE is synchronized with the anchor UE or not.

[0035] According to a particular exemplary embodiment, target UE410 can receive synchronization status assistance information from one or more of the second UEs (i.e., anchors 1-4 or UE412-418; see Figures 4A-4C, operations 4 and 4a-4e), which may include one or more of the above exemplary embodiments based on the requested information type. For example, if the information is of type 1, target UE410 can receive from anchor UE412 the IDs and / or synchronization levels of other nodes synchronized with anchor UE412 (e.g., anchors 414 and 416), as well as the IDs of other synchronized UE414-418, and the synchronization level L2 between the second UE412 and the other UE414-418. In other exemplary embodiments, the level may not be limited to level L2, and there may be multiple synchronization levels. If the information is of type 2, the information may include the synchronization level between the second UE412 and the designated third UE414. Furthermore, if the information is of type 3, it may include information about the SyncRef source of the second UE (e.g., the SyncRef UE ID), or whether the same reference source 420 is also used in the third UE 414.

[0036] In a particular exemplary embodiment, after the target UE410 has obtained the requested synchronization status assistance information, the target UE410 may perform anchor UE (re)selection for SL positioning (any of anchors 1 to 4 or UE412-418; see Figures 4A-4C, operation 5) based at least on the synchronization status assistance information. After an anchor UE (e.g., anchor 1 or UE412) has been selected, the target UE410 may establish and perform SL communication with the selected anchor UE (e.g., anchor 1 or UE412; see Figures 4A-4C, operations 6-8).

[0037] According to a particular exemplary embodiment, a second UE412 can receive a request sent from the first UE410 (see Figure 4A, Operation 2), which may request synchronization status information. After the second UE412 receives the request, it can perform a synchronization status evaluation in accordance with the request (see Figure 4A, Operation 3). For example, if the request is a Type 1 or Type 2 request, the second UE412 (Anchor 1) can coordinate with other anchor UEs 414-418 (e.g., Anchors 2-4) regarding their positioning synchronization status. The second UE412 can also receive positioning signals from the other anchor UEs 414-418, calculate the signal transmission time based on the position information of the anchor UEs, and / or estimate the synchronization accuracy by taking into account PRS transmission failures of the anchor UEs. Furthermore, the second UE412 can communicate with a positioning reference point and request synchronization information from the other anchor UEs (414-418). Synchronization information can refer to the time drift between the transmission times of reference signals between given devices (e.g., between anchor UEs). In some exemplary embodiments, the second UE 412 may use techniques such as ultra-wideband (UWB) signals for determining the synchronization accuracy. In certain exemplary embodiments, if the requirement is a type 3 requirement, the second UE 412 may estimate its synchronization PRS drift compared to its synchronization reference source 420 or positioning reference point.

[0038] According to a particular exemplary embodiment, the second UE412 may transmit synchronization status assistance information to the third UE414 in accordance with the received request (see Figures 4A–4C, operations 4 and 4a–4e). According to another exemplary embodiment, the second UE412 may receive an SL positioning establishment request from the target UE (see Figures 4A–4C, operation 6) and, after receiving the SL positioning establishment request, perform SL positioning together with the target UE410 (see Figures 4A–4C, operations 7 and 8).

[0039] Figures 4A–4C further illustrate exemplary signal flow diagrams 400 according to a particular exemplary embodiment. As shown in Figures 4A–4C, target UE 410 can request one or more initially selected anchor nodes 1–4 (i.e., anchor UEs 412–418) to provide feedback with respect to the anchor nodes with which they are synchronized (e.g., anchor 1, 2, anchor 1, 3, anchor 1, 4, anchor 2, 3, etc.).

[0040] In operation 1, the target UE410 can detect possible anchor UEs (anchors 1-4) and select a subset of anchor UEs (e.g., anchors 1 and 2) to trigger an initial SL positioning session. According to certain exemplary embodiments, the detection by the target UE410 can be performed using a direct discovery model (e.g., models A and / or B) or an indirect model. The target UE410 can then select an initial set of anchor nodes for positioning information exchange. According to certain exemplary embodiments, the selection can be based on basic information received from the discovery message (i.e., received signal quality, periodicity, and / or bandwidth), as well as additional information obtained by measurement / estimation of the received reference signal (or discovery message). For example, the measurement / estimation may include proximity, positioning experience, line-of-sight (LOS) conditions, received reference signal received power (RSRP), or reference signal received quality (RSRQ). In the example shown in Figures 4A-4C, it can be assumed that the target UE410 selects anchor nodes 1 through 4 (i.e., anchors 412-418) for initial positioning information exchange. However, in other exemplary embodiments, more anchors may be selected.

[0041] In operation 2, target UE 410 can send a request to at least one of the initially selected anchor UEs (e.g., one or more of anchor nodes 1-4). The request may include a request for assistance information about the synchronization status (and possibly additional information required for SL positioning). In certain exemplary embodiments, the request may be a request for anchors synchronized together within a threshold (e.g., Embodiment 1, 2a in Figure 4A). For example, in this exemplary embodiment, target UE may determine a synchronization accuracy threshold (e.g., x0nsec) and request the selected anchor node to provide feedback with the IDs of other anchor nodes (e.g., any of anchors 412-418, or anchors other than 412-418) that are synchronized together with the selected anchor node within a predefined threshold. As shown in Figures 4A-4C, target UE 410 can send a request to anchor nodes 1-4. Alternatively, in another exemplary embodiment, the target UE410 may request the selected anchors 1-4 to report any unsynchronized anchors (i.e., other anchors different from anchors 412-418) within a specific area.

[0042] In other exemplary embodiments, the request may be a request for a group of synchronized anchors that satisfy a synchronization accuracy threshold set by the target UE (e.g., Embodiment 2b in Figure 4A). For example, in this exemplary embodiment, the target UE 410 may request anchor nodes 1-4 to provide feedback on at least N group of synchronized UEs (i.e., the same anchors as anchors 412-418, or different anchors from anchors 412-418) and their corresponding synchronization accuracy levels. In certain exemplary embodiments, the synchronization accuracy levels may correspond to a discretized number or level, such as low, medium, and high, with different accuracy value ranges.

[0043] According to certain exemplary embodiments, the request may be a request for the synchronization status of another anchor UE (e.g., Embodiment 3, 2b in Figure 4A). For example, in this exemplary embodiment, the target UE can determine an anchor node (or a set of anchor nodes) (e.g., Anchor 1) and a synchronization threshold. The target UE can then request the other anchor node to provide feedback to the target UE regarding whether the other anchor node is synchronized with the specified anchor node (i.e., Anchor 1) within a predefined threshold. Alternatively, in other exemplary embodiments, the target UE may request anchors 1-4 to provide feedback regarding their synchronization accuracy levels.

[0044] In certain exemplary embodiments, the request may be a request for a synchronization reference source (e.g., Embodiment 4, 2d in Figure 4A). For example, in this exemplary embodiment, the target UE message / request may include a request for information about the reference synchronization source and the anchor node accuracy estimation of the PRS signal of the anchor node relative to the reference source. In other exemplary embodiments, the target UE 410 may request anchor nodes 1-4 to provide information about the source and synchronization level of other anchor nodes corresponding to anchors 412-418, or other anchor nodes corresponding to anchors different from anchors 412-418 (but available for inter-UE coordination between anchor nodes).

[0045] According to a particular exemplary embodiment, the request may be a request for a synchronous reference source at a certain threshold (e.g., Embodiment 5, 2e in Figure 4B). For example, in this exemplary embodiment, the target UE may determine / select a synchronous reference source 420 (e.g., GNSS) and a threshold margin (e.g., x1nsec) and request a response from an anchor node (e.g., a candidate anchor UE) that uses a similar reference source 420 and is synchronized within a predefined threshold.

[0046] In addition to the various requests that can be sent by the target UE as described above, in other exemplary embodiments, the target UE may also request feedback from anchor nodes 1-4 regarding the sustainability of synchronization between anchor nodes 1-4. In this exemplary embodiment, a selected anchor node may provide feedback on the duration for which it can maintain synchronization (at a predefined level of precision and reliability) with other anchor nodes (or reference sources), such as anchors 412-418 or any additional anchors. In other exemplary embodiments, the target UE may also request feedback from a selected anchor node regarding the supported coverage and duration of the selected anchor node's SL-PRS transmission. In some exemplary embodiments, some anchor nodes may be able to broadcast SL-PRS in a specific direction (i.e., a specific panel in FR2) for a limited period of time, and may have limited power (or beam gain in FR2) for SL-PRS transmission at higher power that can be received from longer distances when the target UE is mobile. In certain exemplary embodiments, depending on the scenario, target UE 410 may not necessarily request all anchor UEs 412-418 to respond.

[0047] Returning to Figure 4A, in operation 3, anchor nodes 1-4 can receive requests from the target UE and perform request synchronization evaluation. According to a particular exemplary embodiment, synchronization evaluation between anchor nodes can be achieved by applying various methods, such as coordination between anchor nodes, communication with a positioning reference unit, or the use of UWB signals.

[0048] In operation 4, the anchor UE can respond to the target UE positioning synchronization request by providing the target UE with at least the required synchronization information. For example, in a particular exemplary embodiment, in response to the target UE request in operation 2a (e.g., 4a Embodiment 1 response in Figure 4A), where the target UE requests to receive the IDs of the nodes synchronized together with a precision threshold of x0nsec, the synchronization information may include a response from anchor node 1 stating that anchor node 1 is synchronized with anchor nodes 2 and 3. Furthermore, anchor node 2 may respond that it is synchronized with anchor nodes 1 and 3. In addition, anchor node 3 may respond that it is synchronized with anchor nodes 1 and 2. Furthermore, anchor node 4 may respond that it is synchronized with anchor node 5 (anchor node 5 not shown in Figure 4A).

[0049] As further shown in Figure 4A, in response to the target UE request in operation 2b (e.g., 4b Embodiment 2 response in Figure 4A), where the target UE requests to receive the synchronization level (SL) in addition to the IDs of the nodes synchronized together, anchor node 1 may respond that it is synchronized with anchor node 2 at an SL value of SL=y12nsec and with anchor node 3 at SL=y23nsec. Furthermore, anchor node 3 may respond that it is synchronized with anchor node 2 at SL=y23nsec and with anchor node 1 at SL=y13nsec. In addition, anchor node 4 may respond that it is synchronized with anchor node 5 at SL=y45nsec.

[0050] Figure 4A also shows it as a response to a target UE request in operation 2c (e.g., 4c in Figure 4, Embodiment 3 response), where the target UE requests the synchronization status with another anchor UE (i.e., whether each anchor node is synchronized with anchor node 1 at a better SL than 1xnsec). In this exemplary embodiment, anchor node 2 may respond that it is synchronized with anchor node 1 at SL=y12nsec. Furthermore, anchor node 3 may respond that it is synchronized with anchor node 1 at SL=y13nsec. In addition, anchor node 4 may respond with an unknown synchronization status with anchor node 1.

[0051] As further shown in Figure 4, in response to the target UE request in operation 2d, where the target UE requests information about the anchor node's reference synchronization source (RSS) and the estimated PRS estimation accuracy of the anchor node (e.g., 4d in Figure 4A, Embodiment 4 response), anchor node 1 may respond that its RSS=GNSS and SL=z1nsec. Furthermore, anchor node 2 may respond that its RSS=GNSS and SL=z2nsec. In addition, anchor node 3 may respond that its RSS=GNSS and SL=z3nsec. Furthermore, anchor node 4 may respond that its RSS=LTE eNB and SL=z4nsec.

[0052] In Figure 4A, in response to the target UE request in operation 2e, where the target UE asks whether the anchor node is using GNSS as the reference synchronization source 420 with a better SL than w0nsec (e.g., response in embodiment 5, 4e in Figure 4B), anchor node 1 may respond with "yes" with SL=z1nsec. Furthermore, anchor node 2 (UE414) may respond with "yes" with SL=z2nsec. In addition, anchor node 3 (UE416) may respond with "yes" with SL=z3nsec, and anchor node 4 may or may not respond.

[0053] In operation 5 of Figure 4B, the target UE410 can recognize that the anchor nodes (e.g., anchor nodes 1, 2, and 3) are well synchronized with each other, and the same applies to anchor node 4 (UE418) and anchor node 5 (not shown in Figure 4B, but similar to UE217 or UE219 in Figures 2A-2B). By taking other factors (e.g., received signal power / quality, bandwidth, signal periodicity, signal duration, etc.) into consideration, the target UE can decide to establish a positioning session with anchor nodes 1, 2, and 3. In operation 6, as further shown in Figure 4C, the target UE410 can establish a positioning session with the selected anchor nodes (e.g., anchor nodes 1, 2, and 3). In addition, in operation 7, anchor nodes 1, 2, and 3 can broadcast SL-PRS to the target UE410, and in operation 8, the target UE410 can perform TDOA positioning based on the received SL-PRS signal.

[0054] Figure 5 shows an exemplary flowchart of the method according to a particular exemplary embodiment. In one exemplary embodiment, the method of Figure 5 can be implemented by a network entity, network node, or group of network elements within a 3GPP system such as LTE or 5G-NR. For example, in one exemplary embodiment, the method of Figure 5 can be implemented by a target UE similar to device 10 or 20 shown in Figure 7 as an example.

[0055] According to a particular exemplary embodiment, the method of Figure 5 may include, in 500, receiving one or more messages from one or more devices in a selected set of devices. According to a particular exemplary embodiment, each of the one or more messages may include synchronization information. The method may also include, in 505, selecting at least one device in the selected set of devices for a positioning communication session based on the synchronization information. The method may further include, in 510, performing a position estimation of the device based on a positioning signal received through the positioning communication session from at least one device in the selected set of devices.

[0056] According to certain exemplary embodiments, the synchronization information may include identifiers of one or more other devices in the selected device set that are synchronized with one or more devices in the selected device set and one or more devices different from the selected set of devices; identifiers of one or more other devices in the selected device set; the level of synchronization between one or more devices in the selected device set and one or more devices different from the selected set of devices and the selected set of devices; the level of synchronization between one or more devices in the selected device set and one or more devices different from the selected set of devices and the selected set of devices; an indicator showing that one or more devices in the selected device set are using the same synchronization reference source as one or more other devices in the selected device set and one or more devices different from the selected set of devices; or an indicator showing the reliability of the synchronization.

[0057] According to some exemplary embodiments, the method may also include selecting a set of devices from a set of devices and sending a request to one or more devices in the selected set of devices for synchronization information from the selected set of devices. According to certain exemplary embodiments, the selection of a set of devices is performed before sending the request for synchronization information. According to other exemplary embodiments, the positioning signal received from at least one device in the selected set of devices may include a positioning reference signal.

[0058] In certain exemplary embodiments, the synchronization information may include synchronization status assistance information indicating at least a synchronization level threshold. In some exemplary embodiments, the positioning signal may be received from at least one device in a selected set of devices via one or both of the sidelink interface and / or air interface. In other exemplary embodiments, the synchronization information may be received from one of the following: a network node, a peer anchor user device, or a global navigation satellite system. In further exemplary embodiments, the selected set of devices may include an anchor user device, where the device is a target user device.

[0059] Figure 6 shows an exemplary flowchart of the method according to a particular exemplary embodiment. In one exemplary embodiment, the method of Figure 6 can be implemented by a network entity, network node, or group of network elements within a 3GPP system such as LTE or 5G-NR. For example, in one exemplary embodiment, the method of Figure 6 can be implemented by an anchor UE (i.e., anchor node) similar to device 10 or 20 shown in Figure 7 as an example.

[0060] According to a particular exemplary embodiment, the method in Figure 6 may include, in 600, receiving a request from a device for synchronization information. The method may also include, in 605, performing a synchronization status evaluation using one or more devices in a set of devices in accordance with the received request. The method may further include, in 610, sending one or more messages to the device based on the synchronization status evaluation. According to a particular exemplary embodiment, each of the one or more messages may include synchronization information. In addition, the method may also include, in 615, receiving a positioning session establishment request based on the synchronization information. Furthermore, the method may include, in 620, performing positioning with the device in response to the positioning establishment request.

[0061] According to certain exemplary embodiments, performing a synchronization status evaluation may include at least one of the following: coordinating with one or more other devices in the device set regarding positioning synchronization status; receiving positioning signals from one or more other devices in the device set, calculating signal transmission times based on positional information of one or more devices in the device set, estimating synchronization accuracy by taking into account positioning reference signal transmission failures; or communicating with a positioning reference point and requesting synchronization information from one or more other devices in the device set.

[0062] According to some exemplary embodiments, performing a synchronization status evaluation may include estimating the device's synchronization positioning reference signal drift compared to the device's synchronization reference source or positioning reference point. According to other exemplary embodiments, the synchronization information may include at least one of the following: identifiers of one or more other devices in the device set that are synchronized with one or more devices in the device set; the level of synchronization between the identifiers of one or more other devices in the device set and one or more devices in the device set and one or more other devices in the device set; the level of synchronization between one or more devices in the device set and one or more other devices in the device set; an indication that one or more devices in the device set are using the same synchronization reference source as one or more other devices in the device set; or an indication of synchronization reliability.

[0063] In certain exemplary embodiments, the synchronization information may include synchronization status assistance information indicating at least a synchronization level threshold. In some exemplary embodiments, the synchronization information is transmitted from one of the following: a network node, a peer anchor user device, or a global navigation satellite system. In other exemplary embodiments, one or more other devices in the device set may include an anchor user device, and the device is a target user device.

[0064] In certain exemplary embodiments, the device 10 may include at least one processor 12 and at least one memory 14 containing computer program code. The at least one memory 14 and the computer program code may be configured to store instructions, which, when executed by the at least one processor 12, cause the device 10 to receive one or more messages from one or more devices in a selected set of devices (e.g., steps 4a-4e in Figures 4A-4C). According to certain exemplary embodiments, each of the one or more messages may include synchronization information. According to other exemplary embodiments, the device 10 may also be caused to select at least one device in a selected set of devices for a positioning communication session based on the synchronization information (e.g., steps 5 and 6 in Figures 4A-4C). According to further exemplary embodiments, the device 10 may be caused to perform position estimation of the device based on positioning signals received through the positioning communication session from at least one device in the selected set of devices (e.g., steps 7 and 8 in Figures 4A-4C).

[0065] In certain exemplary embodiments, the synchronization information may include at least one of the following: identifiers of one or more other devices in the selected device set that are synchronized with one or more devices in the selected device set and one or more devices different from the selected set of devices (e.g., Type 1 information); identifiers of one or more other devices in the selected device set; and the level of synchronization between one or more devices in the selected device set and one or more devices different from the selected set of devices and the selected set of devices (e.g., Type 1 information); the level of synchronization between one or more devices in the selected device set and one or more devices different from the selected set of devices and the selected set of devices (e.g., Type 2 information); an indication that one or more devices in the selected device set are using the same synchronization reference source as one or more other devices in the selected device set and one or more devices different from the selected set of devices (e.g., Type 3 information); or an indication of the reliability of the synchronization.

[0066] According to certain exemplary embodiments, at least one memory 14 and computer program code may be further configured to store instructions, which, when executed by at least one processor 12, cause the device 10 to select one set of devices from a plurality of sets of devices (e.g., step 1 in Figures 4A-4C) and to send a request to one or more devices in the selected set of devices for synchronization information from the selected set of devices (e.g., steps 2a-2e in Figures 4A-4C). According to some exemplary embodiments, the selection of a set of devices may be performed before sending the request for synchronization information.

[0067] In certain exemplary embodiments, the positioning signal received from at least one device in the selected set of devices may include a positioning reference signal (e.g., steps 7 and 8 in Figures 4A-4C). In some exemplary embodiments, the synchronization information may include synchronization status assistance information indicating at least a synchronization level threshold (e.g., steps 2a-2e in Figures 4A-4C). In other exemplary embodiments, the positioning signal may be received from at least one device in the selected set of devices via either or both of the sidelink interface and / or air interface (e.g., step 7 in Figure 4A-4C).

[0068] According to certain exemplary embodiments, synchronization information is received from one of the following: a network node, a peer anchor user device, or a global navigation satellite system (e.g., steps 4a-4e and 5 in Figures 4A-4C). According to further exemplary embodiments, a selected set of devices may include anchor user devices (e.g., 412-418), and the device is a target user device (e.g., 410).

[0069] In certain exemplary embodiments, the device 20 may include at least one processor 22 and at least one memory 24 containing computer program code. The at least one memory 24 and the computer program code may be configured to store instructions, which, when executed by the at least one processor 22, cause the device 20 to receive a request from a device for synchronization information (e.g., steps 2a-2e in Figure 4A-4C). According to other exemplary embodiments, the device 20 may also be caused to perform a synchronization status evaluation using one or more devices in a set of devices in accordance with the received request (e.g., step 3 in Figure 4A-4C). According to further exemplary embodiments, the device 20 may be caused to send one or more messages to that device based on the synchronization status evaluation (e.g., steps 4a-4e in Figure 4A-4C). According to certain exemplary embodiments, each of the one or more messages contains synchronization information. According to other exemplary embodiments, the device 20 may be caused to receive a positioning session establishment request based on the synchronization information (e.g., step 6 in Figure 4A-4C). According to further exemplary embodiments, the apparatus 20 may be made to perform positioning together with the device in response to a positioning establishment request (for example, steps 7 and 8 in Figures 4A-4C).

[0070] In certain exemplary embodiments, performing a synchronization status evaluation may include at least one of the following: coordinating with one or more other devices in the device set regarding positioning synchronization status (e.g., a Type 1 or Type 2 information request); receiving positioning signals from one or more other devices in the device set, calculating signal transmission times based on position information of one or more devices in the device set, and estimating synchronization accuracy by taking into account positioning reference signal transmission failures (e.g., a Type 1 or Type 2 information request); or communicating with a positioning reference point and requesting synchronization information from one or more other devices in the device set (e.g., a Type 1 or Type 2 information request). In some exemplary embodiments, performing a synchronization status evaluation may include estimating the device's synchronous positioning reference signal drift compared to the device's synchronization reference source or positioning reference point (e.g., a Type 3 information request). In other exemplary embodiments, the synchronization information includes at least one of the following: identifiers of one or more other devices in the device set that are synchronized with one or more devices in the device set (e.g., type 1 information); the level of synchronization between the identifiers of one or more other devices in the device set and one or more devices in the device set and one or more other devices in the device set (e.g., type 1 information); the level of synchronization between one or more devices in the device set and one or more other devices in the device set (e.g., type 2 information); an indication that one or more devices in the device set are using the same synchronization reference source as one or more other devices in the device set (e.g., type 3 information); or an indication of the reliability of the synchronization.

[0071] In certain exemplary embodiments, the synchronization information may include synchronization status assistance information indicating at least a synchronization level threshold (e.g., steps 2a-2e in Figures 4A-4C). In some exemplary embodiments, the synchronization information may be transmitted from one of the following: a network node, a peer anchor user device, or a global navigation satellite system (e.g., steps 4a-4e and 5 in Figures 4A-4C). In other exemplary embodiments, one or more other devices in the device set may include anchor user devices (e.g., 412-418), and the device may be a target user device (e.g., 410).

[0072] Figure 7 shows a set of devices 10 and 20 according to a particular exemplary embodiment. In a particular exemplary embodiment, device 10 may be an element in a communication network or an element related to such a network, such as a target UE, anchor UE, mobile equipment (ME), mobile station, mobile device, fixed device, IoT device, or other device. It should be noted that those skilled in the art will understand that device 10 may include components or features not shown in Figure 7.

[0073] In some exemplary embodiments, the device 10 may include one or more processors, one or more computer-readable storage media (e.g., memory, storage, etc.), one or more radio access components (e.g., modems, transceivers, etc.), and / or user interfaces. In some exemplary embodiments, the device 10 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-IoT, Bluetooth, NFC, MultiFire, and / or any other radio access technologies. It should be noted that those skilled in the art will understand that the device 10 may include components or features not shown in Figure 7.

[0074] As shown in the example in Figure 7, the device 10 may include or be coupled to a processor 12 for processing information and executing instructions or operations. The processor 12 can be any type of general-purpose or purpose-specific processor. In fact, the processor 12 may include, for example, one or more of the following: a general-purpose computer, a dedicated computer, a microprocessor, a digital signal processor (DSP), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), and a processor based on a multicore processor architecture. Although Figure 7 shows a single processor 12, multiple processors may be utilized according to other exemplary embodiments. For example, it should be understood that in certain exemplary embodiments, the device 10 may include two or more processors capable of forming a multiprocessor system that supports multiprocessing (for example, in this case, the processor 12 may represent a multiprocessor). According to certain exemplary embodiments, the multiprocessor system may be tightly coupled or loosely coupled (for example, forming a computer cluster).

[0075] The processor 12 can perform functions related to the operation of the device 10, including, as some examples, precoding antenna gain / phase parameters, encoding and decoding individual bits that form a communication message, formatting information, and overall control of the device 10, including the processes and examples shown in Figures 1-6.

[0076] The device 10 may further include or be coupled to a memory 14 (internal or external), which may be coupled to the processor 12 to store information and instructions that can be executed by the processor 12. The memory 14 may consist of one or more memories of any type suitable for the local usage environment and may be implemented using any suitable volatile or non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. For example, the memory 14 may consist of any combination of random access memory (RAM), read-only memory (ROM), static storage such as magnetic disks or optical disks, hard disk drives (HDDs), or any other type of non-temporary machine-readable or computer-readable medium. Instructions stored in the memory 14 may include program instructions or computer program code that, when executed by the processor 12, enable the device 10 to perform the tasks described herein.

[0077] In certain exemplary embodiments, the device 10 may further include, or be further coupled to, a (internal or external) drive or port configured to accept and read an external computer-readable storage medium, such as an optical disc, a USB drive, a flash drive, or any other storage medium. For example, the external computer-readable storage medium may store a computer program or software to be executed by the processor 12 and / or the device 10 to perform any of the methods and examples shown in Figures 1-6.

[0078] In some exemplary embodiments, the device 10 may include or be coupled to one or more antennas 15 for receiving downlink signals and for transmitting from the device 10 via UL. The device 10 may further include a transceiver 18 configured to transmit and receive information. The transceiver 18 may also include a radio interface (e.g., a modem) coupled to the antenna 15. The radio interface may support multiple radio access technologies, including one or more of GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, etc. The radio interface may include other components for processing symbols such as OFDMA symbols carried by the downlink or UL, such as filters, converters (e.g., digital-to-analog converters), symbol demappers, signal shaping components, and inverse fast Fourier transform (IFFT) modules.

[0079] For example, the transceiver 18 may be configured to modulate information onto a carrier waveform for transmission by the antenna 15, and to demodulate the information received via the antenna 15 for further processing by other elements of the device 10. In other exemplary embodiments, the transceiver 18 may be capable of directly transmitting and receiving signals or data. In addition to or instead of this, in some exemplary embodiments, the device 10 may also include input and / or output devices (I / O devices). In certain exemplary embodiments, the device 10 may further include a user interface, such as a graphical user interface or a touchscreen.

[0080] In certain exemplary embodiments, memory 14 stores software modules that, when executed by processor 12, provide functionality. These modules may include, for example, an operating system that provides operating system functionality to device 10. Memory may also store one or more functional modules, such as applications or programs, to provide additional functionality to device 10. Components of device 10 may be implemented in hardware form, or as any suitable combination of hardware and software. According to certain exemplary embodiments, device 10 may optionally be configured to communicate with device 20 via a wireless communication link 70 or a wired communication link 70 using any radio access technology, such as NR.

[0081] According to certain exemplary embodiments, the processor 12 and memory 14 may be included in a processing circuit or control circuit, or may form part of a processing circuit or control circuit. In addition, in some exemplary embodiments, the transceiver 18 may be included in a transmit / receive circuit, or may form part of a transmit / receive circuit.

[0082] For example, in a particular exemplary embodiment, the device 10 may be controlled by the memory 14 and the processor 12 to receive one or more messages from one or more devices in a selected set of devices. According to a particular exemplary embodiment, each of the one or more messages may include synchronization information. The device 10 may also be controlled by the memory 14 and the processor 12 to select at least one device in the selected set of devices for a positioning communication session based on the synchronization information. The device 10 may also be further controlled by the memory 14 and the processor 12 to perform position estimation of the device based on positioning signals received through the positioning communication session from at least one device in the selected set of devices.

[0083] In other exemplary embodiments, the device 10 may be controlled by memory 14 and processor 12 to receive a request from a device for synchronization information. The device 10 may also be controlled by memory 14 and processor 12 to perform a synchronization status evaluation using one or more devices in a set of devices in accordance with the received request. The device 10 may further be controlled by memory 14 and processor 12 to send one or more messages to that device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may contain synchronization information. Furthermore, the device 10 may be controlled by memory 14 and processor 12 to receive a positioning establishment request based on the synchronization information. In addition, the device 10 may be controlled by memory 14 and processor 12 to perform positioning with that device in response to the positioning establishment request.

[0084] As shown in the example in Figure 7, the device 20 can be a network, a core network element, or an element within or related to a communication network, such as a gNB, cell, or NW. It should be noted that those skilled in the art will understand that the device 20 may include components or features not shown in Figure 7.

[0085] As shown in the example in Figure 7, the device 20 may include a processor 22 for processing information and executing instructions or operations. The processor 22 can be any type of general-purpose or purpose-specific processor. For example, the processor 22 may include, as an example, one or more of the following: a general-purpose computer, a dedicated computer, a microprocessor, a digital signal processor (DSP), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), and a processor based on a multicore processor architecture. Although Figure 7 shows a single processor 22, multiple processors may be used according to other exemplary embodiments. For example, it should be understood that in certain exemplary embodiments, the device 20 may include two or more processors capable of forming a multiprocessor system that supports multiprocessing (for example, in this case, the processor 22 may represent a multiprocessor). In certain exemplary embodiments, the multiprocessor system may be tightly coupled or loosely coupled (for example, forming a computer cluster).

[0086] According to certain exemplary embodiments, the processor 22 can perform functions related to the operation of the device 20, which may include, for example, precoding antenna gain / phase parameters, encoding and decoding individual bits that form a communication message, formatting information, and overall control of the device 20, including the processes and examples shown in Figures 1-4.

[0087] The device 20 may further include or be coupled to a memory 24 (internal or external), which may be coupled to the processor 22 to store information and instructions that can be executed by the processor 22. The memory 24 may consist of one or more memories of any type suitable for the local usage environment and may be implemented using any suitable volatile or non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. For example, the memory 24 may consist of any combination of random access memory (RAM), read-only memory (ROM), static storage such as magnetic disks or optical disks, hard disk drives (HDDs), or any other type of non-temporary machine-readable or computer-readable medium. Instructions stored in the memory 24 may include program instructions or computer program code that, when executed by the processor 22, enable the device 20 to perform the tasks described herein.

[0088] In certain exemplary embodiments, the device 20 may further include, or be further coupled to, a (internal or external) drive or port configured to accept and read an external computer-readable storage medium, such as an optical disc, USB drive, flash drive, or any other storage medium. For example, the external computer-readable storage medium may store a computer program or software to be executed by the processor 22 and / or the device 20 to carry out the methods and examples shown in Figures 1-4.

[0089] In certain exemplary embodiments, the device 20 may include or be coupled to one or more antennas 25 for transmitting signals and / or data to and from the device 20. The device 20 may further include or be coupled to a transceiver 28 configured to transmit and receive information. The transceiver 28 may include, for example, multiple radio interfaces, which may be coupled to the antennas 25. The radio interfaces may support multiple radio access technologies, including one or more of GSM, NB-IoT, LTE, 5G, WLAN, Bluetooth, BT-LE, NFC, Radio Frequency Identifier (RFID), Ultra-Wideband (UWB), MulteFire, etc. The radio interfaces may include components such as filters, converters (e.g., digital-to-analog converters), mappers, and Fast Fourier Transform (FFT) modules for generating symbols for transmission over one or more downlinks and for receiving symbols (e.g., via UL).

[0090] Therefore, the transceiver 28 can be configured to modulate information onto a carrier waveform for transmission by the antenna 25, and to demodulate the information received via the antenna 25 for further processing by other elements of the device 20. In other exemplary embodiments, the transceiver 18 may be capable of directly transmitting and receiving signals or data. In addition to or instead of that, in some exemplary embodiments, the device 20 may also include input and / or output devices (I / O devices).

[0091] In certain exemplary embodiments, memory 24 may store software modules that, when executed by processor 22, provide functionality. These modules may include, for example, an operating system that provides operating system functionality to device 20. Memory may also store one or more functional modules, such as applications or programs, to provide additional functionality to device 20. Components of device 20 may be implemented in hardware form, or as any suitable combination of hardware and software.

[0092] According to some exemplary embodiments, the processor 22 and memory 24 may be included in a processing circuit or control circuit, or may form part of a processing circuit or control circuit. In addition, in some exemplary embodiments, the transceiver 28 may be included in a transmitting / receiving circuit, or may form part of a transmitting / receiving circuit.

[0093] In this specification, the term “circuit” can refer to a hardware-only circuit implementation (e.g., analog and / or digital circuits), a combination of hardware circuits and software, a combination of analog hardware circuits and / or digital hardware circuits and software / firmware, any part of a hardware processor and software (including digital signal processors) that work together to cause devices (e.g., devices 10 and 20) to perform various functions, and / or a hardware circuit and / or processor or part thereof that uses software for operation, but may not be present when software is not required for operation. As a further example, in this specification, the term “circuit” can also refer simply to an implementation of a hardware circuit or processor (or more processors) or a part of a hardware circuit or processor and its associated software and / or firmware. The term “circuit” can also refer to a baseband integrated circuit in, for example, a server, a cellular network node or cellular network device, or other computing device or network device.

[0094] In some exemplary embodiments, the apparatus (e.g., apparatus 10 and / or apparatus 20) may include means for carrying out any of the methods, processes, or variations discussed herein. Examples of such means may include one or more processors, memory, controllers, transmitters, receivers, and / or computer program code for causing the operation to be carried out.

[0095] Certain exemplary embodiments may be directed to an apparatus that includes means for receiving one or more messages from one or more devices in a selected set of devices. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. The apparatus may also include means for selecting at least one device in the selected set of devices for a positioning communication session based on the synchronization information. The apparatus may further include means for performing position estimation of the apparatus based on positioning signals received through the positioning communication session from at least one device in the selected set of devices.

[0096] Other exemplary embodiments may also be directed to an apparatus that includes means for receiving a request for synchronization information from a device. The apparatus may also include means for performing a synchronization status evaluation using one or more devices in a set of devices in accordance with the received request. The apparatus may further include means for sending one or more messages to the device based on the synchronization status evaluation. According to a particular exemplary embodiment, each of the one or more messages may include synchronization information. In addition, the apparatus may also include means for receiving a positioning establishment request based on the synchronization information. Furthermore, the apparatus may include means for performing positioning with the device in response to the positioning establishment request.

[0097] Certain exemplary embodiments described herein offer several technical improvements, enhancements, and / or advantages. For example, some exemplary embodiments can enhance positioning accuracy in line with 3GPP requirements for high-precision positioning and customer requirements for industrial indoor positioning. Other exemplary embodiments can provide faster positioning session establishment, because synchronization between anchor candidates can be provided to the server UE (or, depending on the application, the target UE) before the session starts, thereby before accuracy is evaluated. In other words, it can be possible to avoid (re)selection of anchor UEs due to anchor synchronization mismatches.

[0098] A computer program product may include one or more computer executable components configured to perform several exemplary embodiments when the program is being executed. One or more computer executable components may be at least one piece of software code or a portion thereof. Modifications and configurations required to implement the functionality of a particular exemplary embodiment may be implemented as routines, and routines may be implemented as additional or updated software routines. Software routines may be downloaded to the device.

[0099] For example, software or computer program code or a portion thereof may take the form of source code, object code, or some intermediate form, and may be stored in some carrier, distribution medium, or computer-readable medium, and any carrier, distribution medium, or computer-readable medium may be any entity or device capable of carrying a program. Such carriers may include, for example, recording media, computer memory, read-only memory, photoelectric and / or electrical carrier signals, telecommunication signals, and software distribution packages. Depending on the processing power required, a computer program may run in a single electronic digital computer, or it may be distributed across several computers. The computer-readable medium or computer-readable storage medium may be a non-temporary medium.

[0100] In other exemplary embodiments, the function may be implemented by hardware or circuitry contained within the device (e.g., device 10 or device 20), for example, through the use of application-specific integrated circuits (ASICs), programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), or any other combination of hardware and software. In yet another exemplary embodiment, the function may be implemented as a signal, which is an intangible means that can be carried by electromagnetic signals downloaded from the Internet or other networks.

[0101] According to certain exemplary embodiments, a device such as a node, a device, or a corresponding component may be configured as a circuit, a computer, or a microprocessor such as a single-chip computer element, or as a chipset including at least memory for providing storage capacity used for arithmetic operations and an arithmetic processor for performing arithmetic operations.

[0102] Those skilled in the art will readily understand that the present disclosure discussed above can be put into practice using a different sequence of procedures and / or using hardware elements with configurations different from those disclosed. Therefore, although the present disclosure has been described based on these exemplary embodiments, those skilled in the art will also find it obvious that certain modifications, variations, and alternative structures will become apparent, while remaining within the spirit and scope of the exemplary embodiments. While the above embodiments refer to 5G NR and LTE technologies, the above embodiments can also be applied to any other current or future 3GPP technologies, such as LTE Advanced and / or 4G technologies. [Explanation of Symbols]

[0103] 3GPP Third Generation Partnership Project 5G (5th generation) 5GCN 5G Core Network 5GS 5G system BS base station DL Downlink eNB Enhanced Node B gNB 5G or Next Generation Node B ID identifier IE Information Element IIoT (Industrial Internet of Things) IUC UE coordination LMF location management function LTE Long-Term Evolution NR new radio NW Network PRS positioning reference signal RSRP Reference Signal Received Power RSS reference synchronization source RSTD reference signal time difference RTOA (Relative Time of Arrival) Round-trip time (RTT) SL Sidelink TDOA arrival time difference TRP Transmit / Receive Point UE User Equipment UL Uphill Link UWB (Ultra Wideband) V2X Vehicle to Anything WI work item

Claims

1. A target user device, At least one processor, At least one memory containing computer program code and Equipped with, At least one memory and computer program code are configured to store instructions, and when an instruction is executed by at least one processor, the target user device is configured to store at least one, Receiving one or more messages from one or more anchor user devices in a selected set of anchor user devices, wherein each of the one or more messages contains synchronization information. Based on synchronization information, select at least one anchor user device from the selected set of anchor user devices for the positioning communication session, Selecting a set of anchor user devices from multiple sets of anchor user devices, Sending a request for synchronization information to one or more anchor user devices in a selected set of anchor user devices, wherein the selection of the selected set of anchor user devices is performed before sending the request for synchronization information. The position estimation of the target user device is performed based on positioning signals received through a positioning communication session from one or more anchor user devices in the selected set of anchor user devices. The target user device that will execute the command.

2. Synchronization information, Identifiers of one or more other anchor user devices in the selected set of anchor user devices, synchronized with one or more anchor user devices in the selected set of anchor user devices and one or more anchor user devices that are not in the selected set of anchor user devices. Identifiers of one or more other anchor user devices within the selected set of anchor user devices, and the level of synchronization between one or more anchor user devices within the selected set of anchor user devices and one or more other anchor user devices outside the selected set of anchor user devices. The level of synchronization between one or more anchor user devices in the selected set of anchor user devices, one or more other anchor user devices in the selected set of anchor user devices, and one or more anchor user devices that are not part of the selected set of anchor user devices. An indication that one or more anchor user devices in the selected set of anchor user devices are using the same synchronous reference source as one or more other anchor user devices in the selected set of anchor user devices and one or more anchor user devices that are different from the selected set of anchor user devices, or Indicators showing the reliability of synchronization The target user device according to claim 1, comprising at least one of the following.

3. The target user device according to claim 1, wherein a positioning signal received from at least one anchor user device in a selected set of anchor user devices includes a positioning reference signal.

4. The target user device according to any one of claims 1 to 3, wherein the synchronization information includes synchronization status assistance information indicating at least a synchronization level threshold.

5. The target user device according to any one of claims 1 to 3, wherein a positioning signal is received from at least one anchor user device in a selected set of anchor user devices via one or both of the side link interface and the air interface.

6. Synchronization information, Network node, Peer anchor user equipment, or Global Navigation Satellite System A target user device according to any one of claims 1 to 3, which is received from one of the following.

7. An anchor user device, At least one processor, At least one memory containing computer program code and Equipped with, At least one memory and computer program code are configured to store instructions, and when an instruction is executed by at least one processor, the anchor user device is configured to store at least one, Receiving a request for synchronization information from the target user device, In accordance with the received request, perform a synchronization status evaluation using one or more anchor user devices from the set of anchor user devices, Sending one or more messages to a target user device based on a synchronization status evaluation, wherein each of the one or more messages contains synchronization information. Based on synchronization information, receive a positioning session establishment request, In response to a positioning establishment request, positioning is performed relative to the target user equipment. An anchor user device that enables execution.

8. The implementation of synchronous status evaluation is To coordinate with one or more other anchor user devices in a set of anchor user devices regarding positioning synchronization status. Receiving positioning signals from one or more other anchor user devices in a set of anchor user devices, calculating signal transmission time based on the position information of one or more anchor user devices in the set of anchor user devices, and estimating synchronization accuracy by taking into account positioning reference signal transmission failures, or To communicate with a positioning reference point and request synchronization information for one or more other anchor user devices in a set of anchor user devices. The anchor user device according to claim 7, comprising at least one of the following.

9. The implementation of synchronous status evaluation is To estimate the synchronous positioning reference signal drift of an anchor user device compared to the synchronous reference source or positioning reference point of the anchor user device. An anchor user device according to claim 7, including the following:

10. Synchronization information, Identifiers of one or more other anchor user devices in a set of anchor user devices that are synchronized with one or more other anchor user devices in a set of anchor user devices. Identifiers of one or more other anchor user devices in the set of anchor user devices, and the level of synchronization between one or more anchor user devices in the set of anchor user devices and one or more other anchor user devices in the set of anchor user devices. The level of synchronization between one or more anchor user devices in a set of anchor user devices and one or more other anchor user devices in a set of anchor user devices. An indication that one or more anchor user devices in a set of anchor user devices are using the same synchronous reference source as one or more other anchor user devices in the set of anchor user devices, or Indicators showing the reliability of synchronization An anchor user device according to any one of claims 7 to 9, comprising at least one of the following.

11. The anchor user device according to any one of claims 7 to 9, wherein the synchronization information includes synchronization status assistance information indicating at least a synchronization level threshold.

12. Synchronization information, Network node, Peer anchor user equipment, or Global Navigation Satellite System An anchor user device according to any one of claims 7 to 9, transmitted from one of the following.

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