Sidelink synchronization during user equipment selection

Abstract

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

Description

Technology Field

[0001] Some exemplary embodiments may generally relate to mobile or wireless telecommunication systems, such as LTE (Long Term Evolution) or 5th generation (5G) NR (New Radio) access technology, or post-5G or other communication systems. For example, certain exemplary embodiments may relate to devices, systems, and / or methods for sidelink (SL) synchronization during user equipment (UE) selection. Background Technology

[0002] Examples of mobile or wireless telecommunications systems may include UMTS (Universal Mobile Telecommunications System), UTRAN (Terrestrial Radio Access Network), E-UTRAN (LTE Evolved UTRAN), LTE-A (LTE-Advanced), MulteFire, LTE-A Pro, and / or 5th generation (5G) radio access technology or NR access technology. 5G radio systems refer to next-generation (NG) radio systems and network architectures. While 5G network technology is mostly based on NR (new radio) technology, 5G (or NG) networks can also be built on E-UTRAN radio. NR is estimated to provide bit rates of approximately 10–20 Gbit / s and support at least enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC). NR is expected to provide extreme broadband, ultra-strong, low-latency connectivity, and massive networking to support the IoT.

[0003] Some exemplary embodiments may relate to a method. The method may include the step of receiving one or more messages from one or more devices of a set of selected devices. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. The method may also include the step of selecting at least one device of a set of selected devices for a positioning communication session based on the synchronization information. The method may further include the step of performing a positioning estimation of a device based on positioning signals received through a positioning communication session from at least one device of a set of selected devices.

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

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

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

[0007] Other exemplary embodiments may relate to a computer program product that performs the method. The method may include the step of receiving one or more messages from one or more devices of a set of selected devices. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. The method may also include the step of selecting at least one device of a set of selected devices for a positioning communication session based on the synchronization information. The method may further include the step of performing a positioning estimation of a device based on positioning signals received through a positioning communication session from at least one device of a set of selected devices.

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

[0009] Some exemplary embodiments may relate to a method. The method may include the step of receiving a request for synchronization information from a device. The method may also include the step of performing a synchronization status evaluation with one or more devices of a set of devices in accordance with the received request. The method may further include the step of transmitting one or more messages to the device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. Furthermore, the method may include the step of receiving a request to establish a positioning session based on the synchronization information. Additionally, the method may include the step of performing positioning with the device in response to the request to establish a positioning session.

[0010] Other exemplary embodiments may relate 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 to use at least one processor to enable the device to receive a synchronization information request from at least one device. The device may also be caused to perform a synchronization status evaluation with one or more devices of a set of devices in accordance with the received request. The device may further be caused to transmit one or more messages to the device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. Furthermore, the device may be caused to receive a positioning session establishment request based on the synchronization information. Additionally, the device may be caused to perform positioning with the device in response to the positioning establishment request.

[0011] Other exemplary embodiments may relate to a device. The device may include means for receiving a request for synchronization information from the device. The device may also include means for performing a synchronization status evaluation with one or more devices of a set of devices in accordance with the received request. The device may further include means for transmitting one or more messages to the device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. Furthermore, the device may include means for receiving a request to establish a positioning session based on the synchronization information. Additionally, the device may include means for performing positioning with the device in response to the request to establish a positioning session.

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

[0013] Other exemplary embodiments may relate to a computer program product that performs the method. The method may include the step of receiving a synchronization information request from a device. The method may also include the step of performing a synchronization status evaluation with one or more devices of a set of devices in accordance with the received request. The method may further include the step of transmitting one or more messages to the device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. Furthermore, the method may include the step of receiving a positioning session establishment request based on the synchronization information. Additionally, the method may include the step of performing positioning with the device in response to the positioning establishment request.

[0014] Other exemplary embodiments may relate to a device that may include a circuit configured to receive a request for synchronization information from a device. The device may also include a circuit configured to perform a synchronization status evaluation with one or more devices of a set of devices in accordance with the received request. The device may further include a circuit configured to transmit one or more messages to the device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. Furthermore, the device may include a circuit configured to receive a request to establish a positioning session based on the synchronization information. Additionally, the device may include a circuit configured to perform positioning with the device in response to the request to establish a positioning session. Brief explanation of the drawing

[0015] To properly understand the exemplary embodiments, reference should be made to the attached drawings. Figure 1 illustrates an exemplary side link (SL) positioning scenario. Figure 2(a) illustrates an example of SL positioning similar to the downlink-time-to-arrival difference (DL-TDOA). Figure 2(b) illustrates an example of SL positioning similar to uplink-TDOA (UL-TDOA). Figure 3 illustrates an example of priority groups of synchronization reference sources. FIG. 4a illustrates an example of an SL positioning scenario signal flow diagram according to certain exemplary embodiments. FIG. 4b illustrates a subsequent part of the SL positioning scenario signal flow diagram of FIG. 4a according to certain exemplary embodiments. FIG. 4c illustrates an additional subsequent part of the SL positioning scenario signal flow diagram of FIG. 4a according to certain exemplary embodiments. FIG. 5 illustrates additional examples of SL positioning scenario signal flow diagrams according to certain exemplary embodiments. FIG. 6 illustrates an exemplary flowchart of an SL positioning method according to certain exemplary embodiments. FIG. 7 illustrates a set of devices according to certain exemplary embodiments. Specific details for implementing the invention

[0016] It will be readily understood that the components of certain exemplary embodiments, as generally described and illustrated in the drawings herein, can be arranged and designed in a wide variety of different configurations. The following is a detailed description of some exemplary embodiments of systems, methods, devices, and computer program products for SL synchronization during UE selection. For example, certain exemplary embodiments may relate to SL synchronization considerations during anchor UE selection.

[0017] As used herein, “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 mean at least one of the elements, or at least two or more of the elements, or at least all of the elements, where the list of two or more elements is connected by “and” or “or”.

[0018] The features, structures, or characteristics of the exemplary embodiments described throughout this specification may be combined in any suitable manner among one or more exemplary embodiments. For example, throughout this specification, the use of “some embodiments,” “exemplary embodiments,” “some embodiments,” or other similar language indicates that a specific feature, structure, or characteristic described in relation to an embodiment may be included in at least one embodiment. Accordingly, the appearance of phrases such as “in some embodiments,” “exemplary embodiments,” “some embodiments,” “other embodiments,” or other similar language throughout this specification does not necessarily refer to embodiments of the same group, and the described features, structures, or characteristics may be combined in any suitable manner among one or more exemplary embodiments. Additionally, throughout this specification, the terms “cell,” “gNB,” “network,” or other similar language may be used interchangeably. Additionally, throughout this specification, the terms “synchronization,” “synchronization,” “synchronicity,” or other similar language may be used interchangeably.

[0019] As used herein, the target UE may refer to the UE to be positioned, and the anchor UE may refer to a UE that supports the positioning of the target UE (e.g., by transmitting and / or receiving reference signals for positioning through the SL interface). The functions of the anchor UE (i.e., anchor node) may be similar to uplink / downlink (UL / DL) based positioning, and gNBs acting as anchors transmit and receive reference signals to and from target UEs for positioning. Additionally, as used herein, the SL positioning reference signal (PRS) may refer to a reference signal transmitted through the SL for positioning.

[0020] SL PRS (pre)configuration may collectively refer to the (pre)configured parameters of the SL PRS, such as time-frequency resources including bandwidth and period, and direction-related parameters (e.g., beam direction, beam width, number of beams). SL PRS (pre)configuration may also refer to (pre)configured parameters of the SL PRS, such as transmit power. Additionally, coverage or partial coverage may be determined by the network (e.g., Location Management Function (LMF) or gNB), while coverage may be pre-configured and / or determined autonomously by the UEs. SL synchronization considerations during anchor UE selection may also include Roadside Units (RSUs) where the UE type or gNB type fixed infrastructure entity supports V2X (Vehicle-to-Everything) applications. Absolute positioning may mean estimating the location of the UE using 2D / 3D geographic coordinates (e.g., latitude, longitude, altitude) within a coordinate system. Additionally, relative positioning may refer to the estimation of relative positioning with respect to other network elements or other UEs. Additionally, ranging may refer to determining the distance between two UEs and / or the orientation between one UE and other UEs through direct device connections.

[0021] The technical specifications of the 3rd Generation Partnership Project (3GPP) consider Short-Line (SL) positioning in cases such as V2X, public safety, and the Commercial and Industrial Internet of Things (IIoT). Additionally, 3GPP considers scenarios and requirements for in-coverage, partial-coverage, and out-of-coverage NR positioning use cases, with a focus on V2X and public safety use cases. SA1 developed requirements for ranging-based services at 3GPP and developed positioning accuracy requirements for IIoT use cases in out-of-coverage scenarios. Positioning requirements can be captured through Key Performance Indicators (KPIs). KPIs may include, for example, horizontal and vertical accuracy, where vertical accuracy represents elevation accuracy, determining the floor in indoor use cases and distinguishing overlapping tracks in road and rail use cases (e.g., bridges). KPIs may also include positioning service availability, which corresponds to a percentage value obtained by dividing the amount of time the positioning service provides position-related data requiring positioning services within performance requirements by the time the system is expected to provide positioning services according to specifications in the target service area. KPIs may further include positioning service latency, which corresponds to the elapsed time between the event triggering the position-related data decision and the availability of the position-related data at the system interface. Additionally, KPIs may include time to fix (TTFF), which corresponds to the elapsed time between the event triggering the position-related data decision for the first time and the availability of the position-related data at the position system interface. KPIs may also include update rate and energy consumption parameters.

[0022] FIG. 1 illustrates an exemplary SL positioning scenario. SL positioning can enable the location of the target UE (110) to be determined within the precise latency and precise requirements of the corresponding SL positioning session based on SL-PRS transmissions (or SL-PRS exchanges between the anchor UE and the target UE) from a plurality of anchor UEs (112-114) to be received by the target UE (110). For example, as illustrated in FIG. 1, the target UE (110) may be conducting an SL positioning session (i.e., exchanging SL-PRS with at least two anchor UEs (112, 114) to determine the location of the target UE (110). In FIG. 1, the anchor UEs (112, 114) may provide SL-PRS support (including SL-PRS) to the target UE (110) so that the target UE (110) can determine its location.

[0023] FIG. 2(a) illustrates an example of DL-TDOA (DL-Time Difference of Arrival), such as SL TDOA, and FIG. 2(b) illustrates an example of UL-TDOA, such as SL TDOA. The SL-TDOA technique is a positioning technique that does not require bidirectional SL PRS transmission between a transmitter and a receiver. 3GPP supports two types of TDOA techniques, including, for example, DL-TDOA and UL-TDOA. SL-TDOA can be implemented with concepts and principles similar to DL-TDOA and UL-TDOA. In an exemplary embodiment, DL-TDOA and UL-TDOA may correspond to Type 1 and Type 2 of TDOA techniques, respectively. As illustrated in FIG. 2(a), in DL-TDOA (method type 1), the target UE (210) can estimate a reference signal time difference (RSTD) measurement from SL positioning reference signals (212a-218a) transmitted by different anchor UEs (212-218) and compute the location of the target UE (210). As illustrated in FIG. 2(b), in UL-TDOA (type 1), the target UE (210) can transmit SL-PRS (212b-218b) to a number of anchor UEs (212-218), and the anchor UEs (212-218) can measure a relative time of arrival (RTOA) similar to UL-TDOA (type 2). This measurement may be reported to a location computing entity (e.g., LMF (230) or target UE (210)) for positioning estimation of the target UE (210). Since both the DL-TDOA and UL-TDOA procedures may be based on TDOA measurements, both procedures may require accurate time synchronization between reference UEs (212-218) to obtain an accurate positioning estimate of the target UE (210).

[0024] SL positioning may also include SL transmissions organized into frames identified by a direct frame number (DFN). The DFN may enable a UE (e.g., any one of 212-218) to synchronize wireless frame transmissions according to an SL timing reference (220). In an exemplary embodiment, the UEs (212-218) may perform SL synchronization by synchronizing with the same reference (e.g., SL timing reference (220)) so that they have the same SL timing reference (220) for SL communication between neighboring UEs. In an exemplary embodiment, the reference (220) illustrated as a set reference (220) in FIG. 2(a) and FIG. 2(b) may include one or more of a plurality of sources (220a to 220c) for a synchronization reference (SyncRef), such as a Global Navigation Satellite System (GNSS) (220a), an NR cell (gNB) or an EUTRAN cell (eNB) (220b), and a SyncRef UE (220c). In another exemplary embodiment, the SyncRef UE (220c) may be any one of the anchor UE's own internal clocks (e.g., 212c-218c).

[0025] FIG. 3 illustrates an example of priority groups of synchronization reference sources. As illustrated in FIG. 3, the UE (210) can select a SyncRef (e.g., 220) having sources of different priorities (P0 to P6) (where P0 to P6 correspond to the highest priority to the lowest priority, respectively) depending on whether it is GNSS-based synchronization (320a / 220a) (GNSS has the highest priority) or gNB / eNB-based synchronization (320b / 220b) (gNB / eNB has the highest priority).

[0026] As mentioned above (see, for example, FIG. 2(a) and 2(b)), in SL, UEs (212-218) can perform SL synchronization by synchronizing with the same reference source (220) so that they have the same SL timing reference (220) for SL communication between neighboring UEs (e.g., 212-218). If a gNB / eNB (320b / 220b) or GNSS (320a / 220a) cannot be used as a synchronization reference source, a UE (e.g., UE (212)) can perform SL synchronization by synchronizing with a SyncRef UE (e.g., UE (214)). However, during this process, synchronization mismatches may occur between the UEs (212, 214) due to, for example, synchronization mismatches of each UE's SyncRef (e.g., 220d, 220e), UE's own clock stability (e.g., UE clocks (212c, 214c)), and / or UE implementation errors. Therefore, in SL positioning, it may be difficult to support and maintain high-level synchronization between the anchor UEs (212-218), especially considering that the anchor UEs (212-218) may be built with significantly cheaper hardware / software equipment compared to the gNBs (e.g., 220b). Additionally, the anchor UEs (212-218) may have lower processing power than the gNBs (220b), and the anchor UEs (212-218) may also be randomly distributed mobile UEs without any backhaul connection support.

[0027] In TDOA-based SL positioning solutions, positioning accuracy may depend on the synchronization precision between anchor UEs (e.g., 212, 214), and a timing mismatch of 1 nsec can lead to a positioning error of approximately 36 cm. Therefore, to support the SL TDOA method to meet the accuracy requirements of SL positioning, highly synchronized anchor UEs may be required. However, as discussed above, not all anchor UEs (212-218) are well synchronized. Therefore, 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. Taking into account the disadvantages described above, certain exemplary embodiments may provide a method for selecting / determining a set of anchor UEs (212-218) synchronized to a desired precision level so that the UE can perform accurate SL positioning. That is, certain exemplary embodiments may include solutions for a target UE (210) of an SL positioning session having information on the synchronization accuracy between anchor UEs (212-218) to allow high accuracy positioning.

[0028] According to certain exemplary embodiments, the first UE (210) (e.g., target UE) may be configured to perform certain operations with anchor UEs (212-218) including operations illustrated in FIG. 4a-4c, for example, referenced herein. For simplification of description and for illustrative purposes, elements described in FIG. 2 may be used to illustrate the descriptions in FIG. 4a through 4c, for example, the UEs (210 through 218) of FIG. 2 may correspond to the UEs (410 through 418) of FIG. 4a through 4c. Likewise, elements (217, 219, and 220), although not explicitly illustrated in FIG. 4a through 4c, may be considered functionally present for illustrative and illustrative purposes.

[0029] For example, the first UE (410) (e.g., target UE) may select a set of second UEs (412-418) (e.g., one or more of anchors 1-4) as candidate anchor UEs for SL positioning (e.g., see FIG. 4a-4c, operation 1). The first UE (410) may also request sync state support information from at least one second UE (412) (e.g., one or more of candidate anchor 1 UE, anchor 2 UE, anchor 3 UE and / or anchor 4 UE) (e.g., see FIG. 4a-4c, operation 2). According to certain exemplary embodiments, the sync state support information may include at least one or more various information elements (IE). For example, the IEs may include types of sync state support information desired by the target UE (410).

[0030] In some exemplary embodiments, the synchronization state support information type may be type 1, which may include synchronization state information for one or more other UEs (414) (i.e., Anchor 2 in FIG. 4a-4c) that can be mutually synchronized with the second UE (412) (i.e., Anchor 1), which may have a synchronization accuracy within the indicated synchronization accuracy threshold L1. In some exemplary embodiments illustrated in operation 2a, the synchronization accuracy threshold L1 may correspond to a real number (e.g., x0 nsec).

[0031] In some exemplary embodiments, the synchronization accuracy threshold L1 may be explicitly or implicitly indicated in a request (i.e., operation 1) transmitted 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 mutually synchronized UEs (and potentially number (N) of synchronized UEs, in this case N=2 for the UE), IDs of one or more desynchronized UEs (i.e., 217, 219 as shown in FIG. 2), and / or synchronization levels for other mutually synchronized UEs (416-418) (e.g., anchors 3 and 4).

[0032] In other exemplary embodiments (e.g., operation 2c), the IE may include type 2 synchronization status support information, which may include synchronization status information for a synchronization level L2 (i.e., synchronization threshold) for one or more of the third UE(s) (e.g., UE (412)). In some exemplary embodiments, the UE(s) (412) may be indicated by the first UE (410) to a request (i.e., operation 1) to other anchor UEs (414, 416, 418).

[0033] In additional exemplary embodiments, the IE may include a type of information type 3, which may include information related to the synchronization reference source(s) of the second UE (412) (i.e., Anchor 1 UE) or the synchronization reference sources of other mutually synchronized UEs (if available). In some exemplary embodiments, the target UE (410) may select a synchronization reference source (420) (similar to 220 in FIG. 2) and a threshold, and request synchronization support information from anchor UEs (e.g., any one of anchor UEs (412-418)) having the same synchronization reference source (220) within the threshold. In other exemplary embodiments, the request to the second UE (412) may include information regarding synchronization reliability (e.g., dispersion of synchronization errors). For example, synchronization reliability may exist between anchor UEs, between anchor UEs and reference sources, or between anchor UEs and one other selected UE (potentially an anchor UE). Synchronization reliability can ensure that anchor UEs (e.g., anchors 2, 3, anchors 1, 3, anchors 1, 2) are synchronized regardless of whether the target UE is synchronized with the anchor UE.

[0034] According to certain exemplary embodiments, the target UE (410) may receive synchronization status support information from one or more of the second UEs (i.e., anchors 1-4 or UEs (412-418); see FIG. 4a-4c, operations 4 and 4a-4e), and this information may include one or more of the exemplary embodiments above based on the requested information type(s). For example, if the information is of type 1, the target UE (410) may receive from the anchor UE (412) IDs and / or synchronization levels of other nodes mutually synchronized with the anchor UE (412) (e.g., anchors (414 and 416)), and / or IDs of other mutually synchronized UEs (414-418) and a synchronization level L2 between the second UE (412) and the other UEs (414-418). In other exemplary embodiments, the level may not be limited to level L2, and multiple synchronization levels may exist. If the information is of type 2, the information may include a synchronization level between the second UE (412) and the indicated third UE(s) (414). Additionally, if the information is of type 3, the information may include information about the SyncRef source of the second UE (e.g., SyncRef UE ID), or whether the same reference source (420) is used with the third UE (414).

[0035] In some exemplary embodiments, when the target UE (410) obtains the requested synchronization state support information, the target UE (410) may perform an anchor UE (re)selection for SL positioning (any one of anchors 1-4 or UEs (412-418); see FIG. 4a-4c, operation 5) based on at least the synchronization state support information. If an anchor UE(s) (e.g., anchor 1 or UE (412)) is selected, the target UE (410) may establish and perform SL communication with the selected anchor UE(s) (e.g., anchor 1 or UE (412); see FIG. 4a-4c, operations 6-8).

[0036] According to certain exemplary embodiments, the second UE (412) may receive a request transmitted from the first UE (410) (see FIG. 4a, operation 2), wherein the request may be for synchronization status information. When the second UE (412) receives the request, the second UE (412) may perform a synchronization status evaluation (see FIG. 4a, operation 3) in accordance with the request. For example, if the request is a type 1 or type 2 request, the second UE (412) (anchor 1) may cooperate with other anchor UEs (414-418) (e.g., anchors 2-4) regarding the position synchronization status. The second UE (412) may also receive positioning signals from the other anchor UEs (414-418), calculate the signal transmission time based on the anchor UEs' position knowledge and / or estimate the synchronization accuracy by considering the anchor UEs' PRS transmission failures. Additionally, the second UE (412) may communicate with a positioning reference point and request synchronization information from other anchor UEs (414-418). The synchronization information may represent the time drift between the transmission times of reference signals of the given devices (e.g., anchor UEs). In some exemplary embodiments, to determine the synchronization accuracy, the second UE (412) may use techniques such as, for example, ultra-wideband (UWB) signals. In some exemplary embodiments, if the request is a type 3 request, the second UE (412) may estimate the synchronization PRS drift by comparing it with the synchronization reference source (420) or the positioning reference point.

[0037] According to certain exemplary embodiments, the second UE (412) may transmit synchronization status support information to the third UE (414) (see FIG. 4a-4c, operations 4 and 4a-4e) in response to a received request. According to other exemplary embodiments, the second UE (412) may receive a request to establish SL positioning from the target UE (see FIG. 4a-4c, operation 6), and upon receiving the request to establish SL positioning, may perform SL positioning with the target UE (410) (see FIG. 4a-4c, operations 7 and 8).

[0038] FIGS. 4a-4c further illustrate exemplary signal flow diagrams (400) according to certain exemplary embodiments. As illustrated in FIGS. 4a-4c, the target UE (410) may request one or more initially selected anchor nodes 1-4 (i.e., anchor UEs (412-418)) to provide feedback on the anchor nodes being synchronized (e.g., anchors 1, 2; anchors 1, 3; anchors 1, 4; anchors 2, 3, etc.).

[0039] In operation 1, the target UE (410) detects potential anchor UEs (anchors 1-4) and may select a subset of anchor UEs (e.g., anchors 1 and 2) to trigger an initial SL positioning session. According to certain exemplary embodiments, detection by the target UE (410) may be performed using direct search models (e.g., models A and / or B) or indirect models. Subsequently, the target UE (410) may select a set of initial anchor nodes for positioning information exchange. According to certain exemplary embodiments, the selection may be based on basic information received from search messages (i.e., received signal quality, period and / or bandwidth) and additional information achieved by measuring / estimating the received reference signals (or search messages). For example, the measurement / estimation may include proximity, previous positioning experience, line of sight (LOS) conditions, received reference signal received power (RSRP), or reference signal received quality (RSRQ), etc. In the example of FIGS. 4a-4c, it can be assumed that the target UE (410) 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.

[0040] In operation 2, the target UE (410) may 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 at least a request for support information regarding the synchronization status (and potentially additional information required for SL positioning). In certain exemplary embodiments, the request may be for anchors that are mutually synchronized within a threshold (e.g., 2a of Example 1 in FIG. 4a). For example, in this exemplary embodiment, the target UE may determine a synchronization accuracy threshold (e.g., x0 nsec) and request the selected anchor node to provide feedback along with the IDs of other anchor nodes that are mutually synchronized with the selected anchor node within a predefined threshold (e.g., any one of anchors (412-418), or anchors other than 412-418). As illustrated in FIG. 4a-4c, the target UE (410) may send a request to anchor nodes 1-4. Alternatively, in other exemplary embodiments, the target UE (410) may also request selected anchors 1-4 to report anchors that are not synchronized in a given area (i.e., anchors (412-418) and other anchors).

[0041] In other exemplary embodiments, the request may be for mutually synchronized anchors that satisfy a synchronization accuracy threshold set by the target UE (e.g., Example 2b of FIG. 4a). For example, in this exemplary embodiment, the target UE (410) may request anchor nodes 1-4 to provide feedback on at least N mutually synchronized UEs (i.e., anchors identical or different from anchors (412-418)) and the corresponding synchronization accuracy levels. In certain exemplary embodiments, the synchronization accuracy levels may correspond to a discretized number or levels having different accuracy value ranges, such as low, medium, and high.

[0042] According to certain exemplary embodiments, the request may be a request for the synchronization status of other anchor UEs (e.g., 2b of Example 3 in FIG. 4a). For example, in this exemplary embodiment, the target UE may determine a synchronization threshold with anchor node(s) (e.g., anchor1) (or a set of anchor node(s)). Subsequently, the target UE may request other anchor nodes to provide feedback to the target UE regarding whether the other anchor nodes are synchronized with the specified anchor node (i.e., anchor1) within a predefined threshold. Alternatively, in other exemplary embodiments, the target UE may request anchors 1-4 to provide feedback regarding the synchronization accuracy level.

[0043] In some exemplary embodiments, the request may be a request for a synchronization reference source (e.g., 2d of Example 4 of FIG. 4a). For example, in this exemplary embodiment, the target UE message / request may include a request for information regarding the reference synchronization source and an estimation of the accuracy of the anchor node's PRS signals regarding the reference source. In other exemplary embodiments, the target UE (410) may request anchor nodes 1-4 to provide information regarding the source and synchronization level of other anchor nodes corresponding to anchors (412-418) or anchors other than anchors (412-418) (if available due to coordination between UEs between anchor nodes).

[0044] According to certain exemplary embodiments, the request may be a request for a synchronization reference source having a threshold (e.g., 2e of Example 5 of FIG. 4b). For example, in this exemplary embodiment, the target UE may determine / select a synchronization reference source (420) (e.g., GNSS) and a threshold margin (e.g., x1 nsec) and request a response from anchor nodes (e.g., candidate anchor UEs) that use a similar reference source (420) and are synchronized within a predefined threshold.

[0045] In addition to the various requests described above that may be transmitted by the target UE, in other exemplary embodiments, the target UE may request feedback from anchor nodes 1-4 regarding the sustainability of synchronization between anchor nodes 1-4. In this exemplary embodiment, the selected anchor node(s) may provide feedback regarding the duration of time during which synchronization can be maintained (at a predefined precision and reliability level) with other anchor nodes, such as anchors (412-418) or additional anchors (or reference sources). In other exemplary embodiments, the target UE may also request feedback from the selected anchor node regarding the supported coverage and the duration of SL-PRS transmission. In some exemplary embodiments, some anchor nodes may broadcast SL-PRS for a limited time in a specific direction (i.e., a specific panel of FR2) and may have limited power (or beam gain of FR2) to transmit SL-PRS at a higher power that can be received at a greater distance when the target UE is moving. In some exemplary embodiments, depending on the scenario, the target UE (410) may not necessarily request a response from all anchor UEs (412-418).

[0046] Returning to FIG. 4a, in operation 3, anchor nodes 1-4 can receive a request from a target UE and perform a request synchronization evaluation. According to certain exemplary embodiments, the synchronization evaluation between anchor nodes can be achieved by applying various methods such as coordination between anchor nodes, communication with a positioning reference unit, and the use of UWB signals.

[0047] In operation 4, anchor UEs may respond to a target UE positioning synchronization request by providing at least the necessary synchronization information to the target UE. For example, in some exemplary embodiments, as a response to a target UE request in operation 2a of operation 2, where the target UE requests to have IDs of nodes mutually synchronized with an accuracy threshold of x0 nsec (e.g., 4a of response 1 of Example 1 in FIG. 4a), the synchronization information may include a response from anchor node 1 stating that anchor node 1 is synchronized with anchor node 2 and anchor node 3. Additionally, anchor node 2 may respond that it is synchronized with anchor node 1 and anchor node 3. Additionally, anchor node 3 may respond that it is synchronized with anchor nodes 1 and 2. Additionally, anchor node 4 may respond that it is synchronized with anchor node 5 (an anchor node 5 not shown in FIG. 4a).

[0048] As further illustrated in FIG. 4a, in response to the target UE request in operation 2, 2b, where the target UE requests the IDs of mutually synchronized nodes and the synchronization level (SL) (e.g., 4b of the response in Example 2 of FIG. 4a), anchor node 1 sets SL=y 12 Synchronized with anchor node 2 with an SL value of nsec, and SL=y 23 It can respond that it is synchronized with Anchor Node 3 with an SL value of nsec. Additionally, Anchor Node 3 has SL=y 23 Synchronized with anchor node 2 at nsec, and SL=y 13 It can respond that it is synchronized with Anchor Node 1 in nsec. Additionally, Anchor Node 4 has SL = y 45 You can respond that it is synchronized with anchor node 5 in nsec.

[0049] FIG. 4a also illustrates a response to a target UE request in 2c of operation 2, where the target UE requests the synchronization status of another anchor UE (i.e., whether the anchor nodes are synchronized with anchor node 1 with an SL faster than 1x nsec) (e.g., 4c of the response to Example 3 in FIG. 4). In this exemplary embodiment, anchor node 2 has SL=y 12 It can respond that it is synchronized with Anchor Node 1 in nsec. Additionally, Anchor Node 3 has SL = y 13 It can respond that it is synchronized with Anchor Node 1 in nsec. Additionally, Anchor Node 4 can respond that the synchronization status with Anchor Node 1 is unknown.

[0050] As further illustrated in FIG. 4, in response to the target UE request in operation 2d of which the target UE requests information regarding the reference synchronization source (RSS) of the anchor nodes and the estimated PRS estimation accuracy of the anchor nodes (e.g., 4d of response in Example 4 of FIG. 4a), anchor node 1 may respond that its RSS=GNSS and SL=z1 nsec. Additionally, anchor node 2 may respond that its RSS=GNSS and SL=z2 nsec. Additionally, anchor node 3 may respond that its RSS=GNSS and SL=z3 nsec. Additionally, anchor node 4 may respond that its RSS=LTE eNB and SL=z4 nsec.

[0051] In FIG. 4a, in response to a target UE request of operation 2, 2e, in which the target UE asks whether anchor nodes use GNSS with a reference synchronization source (420) having an SL smaller than w0 nsec (e.g., 4e of response of Example 5 in FIG. 4b), anchor node 1 may respond with "Yes" with SL=z1 nsec. Additionally, anchor node 2 (UE (414)) may respond with "Yes" with SL=z2 nsec. Additionally, anchor node 3 (UE (416)) may respond with "Yes" with SL=z3 nsec, and anchor node 4 may or may not provide a response.

[0052] In operation 5 of FIG. 4b, the target UE (410) may recognize that the anchor nodes (e.g., anchor nodes 1, 2, and 3) are sufficiently synchronized with each other, and this applies equally to anchor nodes 4 (UE (418)) and anchor node 5 (not shown in FIG. 4b, but similar to UE (217) or UE (219) in FIG. 2a-2b). The target UE may decide to establish a positioning session with anchor nodes 1, 2, and 3, taking into account other factors (e.g., received signal power / quality, bandwidth, signal period, signal duration length, etc.). As further illustrated in FIG. 4c, in operation 6, the target UE (410) may establish a positioning session with selected anchor nodes (e.g., anchor nodes 1, 2, and 3). Additionally, in operation 7, anchor nodes 1, 2, and 3 can broadcast SL-PRS to the target UE (410), and in operation 8, the target UE (410) can perform TDOA positioning based on the received SL-PRS signal.

[0053] FIG. 5 illustrates an exemplary flowchart of a method according to certain exemplary embodiments. In an exemplary embodiment, the method of FIG. 5 may be performed by a network entity, a network node, or a group of multiple network elements of a 3GPP system such as LTE or 5G-NR. For example, in an exemplary embodiment, the method of FIG. 5 may be performed by a target UE similar to, for example, the devices (10 or 20) illustrated in FIG. 7.

[0054] According to certain exemplary embodiments, the method of FIG. 5 may include, in 500, the step of receiving one or more messages from one or more devices of a set of selected devices. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. The method may also include, in 505, the step of selecting at least one device of a set of selected devices for a positioning communication session based on the synchronization information. The method may further include, in 510, the step of performing a positioning estimation of a device based on positioning signals received through a positioning communication session from at least one device of a set of selected devices.

[0055] According to certain exemplary embodiments, the synchronization information may include at least one of the identifiers of one or more other devices of a set of selected devices that are mutually synchronized with one or more devices of a set of selected devices and one or more devices different from the set of selected devices, identifiers of one or more other devices of a set of selected devices, a synchronization level between one or more devices of a set of selected devices and one or more other devices of a set of selected devices and one or more devices different from the set of selected devices, a synchronization level between one or more devices of a set of selected devices and one or more other devices of a set of selected devices and one or more devices different from the set of selected devices, an indication that one or more devices of a set of selected devices use the same synchronization reference source as one or more other devices of a set of selected devices and one or more devices different from the set of selected devices, or an indication of synchronization reliability.

[0056] According to some exemplary embodiments, the method may also include the step of selecting a set of selected devices from a set of a plurality of devices, and the step of transmitting a synchronization information request from the set of selected devices to one or more devices of the set of selected devices. According to certain exemplary embodiments, the selection of the set of devices is performed prior to transmitting the synchronization information request. According to other exemplary embodiments, positioning signals received from at least one device of the set of selected devices may include a positioning reference signal.

[0057] In some exemplary embodiments, the synchronization information may include synchronization status support information indicating at least a synchronization level threshold. In some exemplary embodiments, positioning signals may be received from at least one device of a set of selected devices via one or both of a sidelink interface and a wireless interface. In other exemplary embodiments, the synchronization information is received from one of a network node, a peer anchor user device, or a global navigation satellite system. In additional exemplary embodiments, the set of selected devices may include an anchor user device, and the device is a target user device.

[0058] FIG. 6 illustrates an exemplary flowchart of a method according to certain exemplary embodiments. In an exemplary embodiment, the method of FIG. 6 may be performed by a network entity, a network node, or a group of multiple network elements of a 3GPP system such as LTE or 5G-NR. For example, in an exemplary embodiment, the method of FIG. 6 may be performed by an anchor UE (i.e., an anchor node) similar to, for example, the devices (10 or 20) illustrated in FIG. 7.

[0059] According to certain exemplary embodiments, the method of FIG. 6 may include, at 600, the step of receiving a synchronization information request from a device. The method may also include, at 605, the step of performing a synchronization status evaluation with one or more devices of a set of devices in accordance with the received request. The method may further include, at 610, the step of transmitting one or more messages to the device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. Furthermore, the method may include, at 615, the step of receiving a request to establish a positioning session based on the synchronization information. Additionally, the method may include, at 620, the step of performing positioning with the device in response to the request to establish a positioning session.

[0060] According to certain exemplary embodiments, the performance of the synchronization state evaluation may include at least one of coordinating with one or more other devices of a set of devices regarding the positioning synchronization state, receiving a positioning signal from one or more other devices of a set of devices, calculating a signal transmission time based on location information of one or more devices of a set of devices, and estimating the synchronization accuracy by considering positioning reference signal transmission failures, or communicating with a positioning reference point, and requesting synchronization information from one or more other devices of a set of devices.

[0061] According to some exemplary embodiments, the performance of the synchronization state evaluation may include estimating the synchronization positioning reference signal drift of the device in comparison with the device's synchronization reference source or positioning reference point. According to other exemplary embodiments, the synchronization information comprises at least one of identifiers of one or more other devices in a set of devices that are mutually synchronized with one or more devices in a set of devices, identifiers of one or more other devices in a set of devices, and a synchronization level between one or more devices in a set of devices and one or more other devices in a set of devices, a synchronization level between one or more devices in a set of devices and one or more other devices in a set of devices, an indication that one or more devices in a set of devices use the same synchronization reference source as one or more other devices in a set of devices, or an indication of the reliability of the synchronization.

[0062] In some exemplary embodiments, the synchronization information may include synchronization status support information indicating at least a synchronization level threshold. In some exemplary embodiments, the synchronization information is transmitted from one of a network node, a peer anchor user device, or a global navigation satellite system. In other exemplary embodiments, one or more other devices of a set of devices may include an anchor user device, and the device is a target user device.

[0063] 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 have instructions that, when executed by the at least one processor (12), cause the device (10) to receive one or more messages from one or more devices of a set of selected devices (e.g., steps 4a-4e of FIGS. 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 of a set of selected devices for a positioning communication session based on the synchronization information (e.g., steps 5 and 6 of FIGS. 4a-4c). According to additional exemplary embodiments, the device (10) may be caused to perform a positioning estimation of the device based on positioning signals received through a positioning communication session from at least one device of a set of selected devices (e.g., steps 7 and 8 of FIG. 4a-4c).

[0064] According to certain exemplary embodiments, the synchronization information may include at least one of the identifiers of one or more devices of a set of selected devices that are mutually synchronized with one or more devices of a set of selected devices and one or more devices that are different from the set of selected devices (e.g., type 1 information), identifiers of one or more devices of a set of selected devices, and a synchronization level between one or more devices of a set of selected devices and one or more other devices of a set of selected devices and one or more devices that are different from the set of selected devices (e.g., type 1 information), a synchronization level between one or more devices of a set of selected devices and one or more other devices of a set of selected devices and one or more devices that are different from the set of selected devices (e.g., type 2 information), an indication that one or more devices of a set of selected devices use the same synchronization reference source as one or more other devices of a set of selected devices and one or more devices that are different from the set of selected devices (e.g., type 3 information), or an indication of synchronization reliability.

[0065] According to certain exemplary embodiments, at least one memory (14) and computer program code may be further configured to store instructions that, when executed by at least one processor (12), cause the device (10) to select a set of selected devices from a set of multiple devices (e.g., step 1 of FIG. 4a-4c) and to transmit a request for synchronization information of the set of selected devices to one or more devices of the set of selected devices (e.g., steps 2a-2e of FIG. 4a-4c). According to some exemplary embodiments, the selection of the set of devices may be performed before transmitting the request for synchronization information.

[0066] According to certain exemplary embodiments, positioning signals received from at least one device of a set of selected devices may include a positioning reference signal (e.g., steps 7 and 8 of FIGS. 4a-4c). In some exemplary embodiments, the synchronization information may include synchronization status support information indicating at least a synchronization level threshold (e.g., steps 2a-2e of FIGS. 4a-4c). In other exemplary embodiments, the positioning signals may be received from at least one device of a set of selected devices via one or both of a sidelink interface and a wireless interface (e.g., step 7 of FIGS. 4a-4c).

[0067] According to certain exemplary embodiments, synchronization information is received from one of a network node, peer anchor user equipment, or global navigation satellite system (e.g., steps 4a-4e and 5 of FIG. 4a-4c). According to further exemplary embodiments, a set of selected devices may include anchor user equipment (e.g., 412-418), and the device is target user equipment (e.g., 410).

[0068] 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 that, when executed by at least one processor (22), cause the device (20) to receive a request for synchronization information from a device (e.g., steps 2a-2e of FIGS. 4a-4c). According to other exemplary embodiments, the device (20) may be caused to perform a synchronization status evaluation with one or more devices of a set of devices in response to a received request (e.g., step 3 of FIGS. 4a-4c). According to further exemplary embodiments, the device (20) may be caused to transmit one or more messages to the device based on the synchronization status evaluation (e.g., steps 4a-4e of FIGS. 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 request to establish a positioning session based on synchronization information (e.g., step 6 of FIGS. 4a-4c). According to further exemplary embodiments, the device (20) may be caused to perform positioning with a device in response to the request to establish a positioning session (e.g., steps 7 and 8 of FIGS. 4a-4c).

[0069] According to certain exemplary embodiments, the performance of the synchronization state evaluation may include at least one of coordinating with one or more other devices of a set of devices regarding the positioning synchronization state (e.g., requesting type 1 or type 2 information), receiving positioning signals from one or more other devices of a set of devices, calculating the signal transmission time based on the position information of one or more devices of a set of devices, and estimating the synchronization accuracy by considering positioning reference signal transmission failures (e.g., requesting type 1 or type 2 information), communicating with a positioning reference point, and requesting synchronization information from one or more other devices of a set of devices (e.g., requesting type 1 or type 2 information). In some exemplary embodiments, the performance of the synchronization state evaluation may include estimating the synchronization positioning reference signal drift of a device by comparing it with the device's synchronization reference source or positioning reference point (e.g., requesting type 3 information). In other exemplary embodiments, the synchronization information includes at least one of identifiers of one or more other devices in a set of devices that are mutually synchronized with one or more devices in a set of devices (e.g., type 1 information), identifiers of one or more other devices in a set of devices, and a synchronization level between one or more devices in a set of devices and one or more other devices in a set of devices (e.g., type 1 information), a synchronization level between one or more devices in a set of devices and one or more other devices in a set of devices (e.g., type 2 information), an indication that one or more devices in a set of devices use the same synchronization reference source as one or more other devices in a set of devices (e.g., type 3 information), or an indication of the reliability of the synchronization.

[0070] In some exemplary embodiments, the synchronization information may include synchronization status support information indicating at least a synchronization level threshold (e.g., steps 2a-2e of FIG. 4a-4c). In some exemplary embodiments, the synchronization information may be transmitted from one of a network node, a peer anchor user device, or a global navigation satellite system (e.g., steps 4a-4e and 5 of FIG. 4a-4c). In other exemplary embodiments, one or more other devices of the set of devices may include anchor user devices (e.g., 412-418), and the device is a target user device (e.g., 410).

[0071] FIG. 7 illustrates a set of devices (10 and 20) according to certain exemplary embodiments. In certain exemplary embodiments, the device (10) may be an element of a communication network or associated with such a network, such as a target UE, an anchor UE, a mobile device (ME), a mobile station, a mobile device, a fixed device, an IoT device, or other device. A person skilled in the art should note that the device (10) may include components or features not illustrated in FIG. 7.

[0072] In some exemplary embodiments, the device (10) may include one or more processors, one or more computer-readable storage media (e.g., memory, storage or similar), one or more wireless access components (e.g., modem, transceiver or similar) and / or a user interface. In some exemplary embodiments, the device (10) may be configured to operate using one or more wireless access technologies such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-IoT, Bluetooth, NFC, MulteFire and / or any other wireless access technology. A person skilled in the art should note that the device (10) may include components or features not illustrated in FIG. 7.

[0073] As illustrated in the example of FIG. 7, the device (10) may include or be coupled with a processor (12) for processing information and executing commands or operations. The processor (12) may be any type of general-purpose or special-purpose processor. In practice, the processor (12) may include, as examples, one or more of general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture. Although a single processor (12) is illustrated in FIG. 7, 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 that can form a multiprocessor system capable of supporting multiprocessing (e.g., in this case, the processor (12) may represent a multiprocessor). According to certain exemplary embodiments, multiprocessor systems may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0074] The processor (12) can perform functions related to the operation of the device (10), and the functions include the processes and examples illustrated in FIGS. 1-6, some examples including pre-coding of antenna gain / phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the device (10).

[0075] The device (10) may be coupled to the processor (12) and may additionally include or be coupled thereto a memory (14) (internal or external) for storing information and instructions that can be executed by the processor (12). The memory (14) may be one or more memories and may be of any type suitable for a local application environment and may be implemented using any suitable volatile or non-volatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, a fixed memory and / or a removable memory. For example, the memory (14) may be composed of random access memory (RAM), read-only memory (ROM), static storage such as a magnetic or optical disk, a hard disk drive (HDD), or any other type of non-transient mechanical or computer-readable media. Instructions stored in the memory (14) may include program instructions or computer program code that enable the device (10) to perform tasks as described herein when executed by the processor (12).

[0076] In some exemplary embodiments, the device (10) may further include or be coupled thereto a drive or port (internal or external) configured to receive 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 illustrated in FIGS. 1–6.

[0077] In some exemplary embodiments, the device (10) may also include or be coupled thereto one or more antennas (15) for receiving downlink signals and transmitting from the device (10) through the UL. The device (10) may further include a transceiver (18) configured to transmit and receive information. The transceiver (18) may also include a wireless interface (e.g., a modem) coupled to the antenna (15). The wireless interface may correspond to a plurality of wireless access technologies including one or more of GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, etc. The wireless interface may include other components such as filters, converters (e.g., digital-to-analog converters, etc.), symbol demappers, signal shaping components, inverse fast Fourier transform (IFFT) modules, etc., to process symbols such as OFDMA symbols returned by the downlink or the UL.

[0078] For example, the transceiver (18) may be configured to modulate information into a carrier waveform for transmission by the antenna(s) (15) and to demodulate information received through the antenna(s) (15) for further processing by other elements of the device (10). In other exemplary embodiments, the transceiver (18) may directly transmit or receive signals or data. Additionally or alternatively, in some exemplary embodiments, the device (10) may include an input and / or output device (I / O device). In certain exemplary embodiments, the device (10) may further include a user interface such as a graphical user interface or a touchscreen.

[0079] In some exemplary embodiments, memory (14) stores software modules that provide functions when executed by the processor (12). The modules may include, for example, an operating system that provides operating system functions to the device (10). Memory may also store one or more function modules, such as applications or programs, to provide additional functions to the device (10). The components of the device (10) may be implemented in hardware or in any suitable combination of hardware and software. According to some exemplary embodiments, the device (10) may be optionally configured to communicate with the device (20) via a wireless or wired communication link (70) according to any wireless access technology, such as NR.

[0080] According to certain exemplary embodiments, the processor (12) and memory (14) may be included in or form part of a processing circuit or control circuit. In addition, in some exemplary embodiments, the transceiver (18) may be included in or form part of a transceiver circuit.

[0081] For example, in certain exemplary embodiments, 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 of a set of selected devices. According to certain exemplary embodiments, 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 of a set of selected devices for a positioning communication session based on the synchronization information. The device (10) may further be controlled by the memory (14) and the processor (12) to perform a positioning estimation of the device based on positioning signals received through a positioning communication session from at least one device of a set of selected devices.

[0082] In other exemplary embodiments, the device (10) may be controlled by memory (14) and processor (12) to receive a synchronization information request from a device. The device (10) may also be controlled by memory (14) and processor (12) to perform a synchronization status evaluation with one or more devices of a set of devices in accordance with the received request. The device (10) may further be controlled by memory (14) and processor (12) to transmit one or more messages to the device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. Additionally, the device (10) may be controlled by memory (14) and processor (12) to receive a positioning establishment request based on the synchronization information. Furthermore, the device (10) may be controlled by memory (14) and processor (12) to perform positioning with the device in response to the positioning establishment request.

[0083] As illustrated in the example of FIG. 7, the device (20) may be a network, core network element or element of a communication network, or may be associated with a network such as a gNB, cell, or NW. A person skilled in the art should note that the device (20) may include components or features not shown in FIG. 7.

[0084] As illustrated in the example of FIG. 7, the device (20) may include a processor (22) for processing information and executing commands or operations. The processor (22) may be any type of general-purpose or special-purpose processor. For example, the processor (22) may include one or more of general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), field programming gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture as examples. Although a single processor (22) is illustrated in FIG. 7, multiple processors may be utilized 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 that can form a multiprocessor system capable of supporting multiprocessing (e.g., in this case, the processor (22) may represent a multiprocessor). In certain exemplary embodiments, multiprocessor systems may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0085] According to certain exemplary embodiments, the processor (22) may perform functions associated with the operation of the device (20), and the functions may include the processes and examples illustrated in FIGS. 1-4, for example, pre-coding of antenna gain / phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the device (20).

[0086] The device (20) may be coupled to the processor (22) and may additionally include or be coupled thereto a memory (24) (internal or external) for storing information and instructions that can be executed by the processor (22). The memory (24) may be one or more memories and may be of any type suitable for a local application environment and may be implemented using any suitable volatile or non-volatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, a fixed memory and / or a removable memory. For example, the memory (24) may be composed of random access memory (RAM), read-only memory (ROM), static storage such as a magnetic or optical disk, a hard disk drive (HDD), or any other type of non-transient mechanical or computer-readable media. Instructions stored in the memory (24) may include program instructions or computer program code that enable the device (20) to perform tasks as described herein when executed by the processor (22).

[0087] In some exemplary embodiments, the device (20) may further include or be coupled thereto a drive or port (internal or external) configured to receive 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 (22) and / or the device (20) to perform the methods and examples illustrated in FIGS. 1-4.

[0088] In some exemplary embodiments, the device (20) may also include or be coupled thereto one or more antennas (25) for transmitting and receiving signals and / or data to and from the device (20). The device (20) may additionally include or be coupled thereto a transceiver (28) configured to transmit and receive information. The transceiver (28) may include a plurality of wireless interfaces that may be coupled to, for example, the antenna(s) (25). The wireless interfaces may correspond to a plurality of wireless 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 wireless interface includes components such as filters, converters (e.g., digital-to-analog converters, etc.), mappers, and Fast Fourier Transform (FFT) modules, and can generate symbols for transmission over one or more downlinks (e.g., via UL) and receive symbols.

[0089] Thus, the transceiver (28) may be configured to modulate information into a carrier waveform for transmission by the antenna(s) (25) and to demodulate information received through the antenna(s) (25) for further processing by other elements of the device (20). In other exemplary embodiments, the transceiver (18) may directly transmit and receive signals or data. Additionally or alternatively, in some exemplary embodiments, the device (20) may include an input and / or output device (I / O device).

[0090] In a given exemplary embodiment, memory (24) may store software modules that provide functions when executed by the processor (22). The modules may include, for example, an operating system that provides operating system functions to the device (20). Memory may also store one or more function modules, such as applications or programs, to provide additional functions to the device (20). The components of the device (20) may be implemented in hardware or in any suitable combination of hardware and software.

[0091] According to some exemplary embodiments, the processor (22) and memory (24) may be included in or form part of a processing circuit or control circuit. Additionally, in some exemplary embodiments, the transceiver (28) may be included in or form part of a transceiver circuit.

[0092] As used herein, the term “circuit” may refer to hardware-only circuit implementations (e.g., analog and / or digital circuits), combinations of hardware circuits and software, any parts of hardware processor(s) together with software (including digital signal processors) that works together to enable devices (e.g., devices (10 and 20) to perform various functions), and / or hardware circuit(s) and / or processor(s) or parts thereof that use software for operation but may not exist when software is not required to operate. As an additional example, as used herein, the term “circuit” may also include a simple implementation of a hardware circuit or processor (or multiprocessors), or a part of a hardware circuit or processor and the accompanying software and / or firmware. The term circuit may also include, for example, a baseband integrated circuit of a server, a cellular network node or device, or other computing or network device.

[0093] In some exemplary embodiments, the device (e.g., device (10) and / or device (20)) may include means for performing the methods, processes, or any variations discussed herein. Examples of means may include one or more processors, memory, controllers, transmitters, receivers, and / or computer program code for causing the performance of operations.

[0094] Some exemplary embodiments may relate to an apparatus comprising means for receiving one or more messages from one or more devices of a set of selected devices. According to some 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 of a set of selected devices for a positioning communication session based on the synchronization information. The apparatus may further include means for performing a positioning estimation of the device based on positioning signals received through a positioning communication session from at least one device of a set of selected devices.

[0095] Other exemplary embodiments may also relate to a device comprising means for receiving a synchronization information request from a device. The device may also include means for performing a synchronization status evaluation with one or more devices of a set of devices in accordance with the received request. The device may further include means for transmitting one or more messages to the device based on the synchronization status evaluation. According to certain exemplary embodiments, each of the one or more messages may include synchronization information. Furthermore, the device may include means for receiving a positioning establishment request based on the synchronization information. Additionally, the device may include means for performing positioning with the device in response to the positioning establishment request.

[0096] The specific exemplary embodiments described herein provide various technical improvements, enhancements, and / or benefits. For example, in some exemplary embodiments, positioning accuracy can be improved to meet 3GPP's precise positioning requirements and customer requirements for industrial indoor positioning. In other exemplary embodiments, synchronization between anchor candidates can be provided to the server UE (or target UE, depending on the application) before the session starts and thereby before accuracy evaluation, thereby enabling faster establishment of a positioning session. In other words, (re)selection of anchor UEs due to anchor synchronization mismatch can be prevented.

[0097] A computer program product may include one or more computer-executable components configured to perform some exemplary embodiments when the program is executed. One or more computer-executable components may be at least one piece of software code or part thereof. Modifications and configurations necessary to implement the functions of some exemplary embodiments may be performed as routine(s), which may be implemented as added or updated software routine(s). Software routine(s) may be downloaded to a device.

[0098] For example, software or computer program code or part thereof may be in the form of source code, object code, or some intermediate form, and may be stored on any kind of carrier, distribution medium, or computer-readable medium that may be any entity or device capable of carrying the program. Such carriers may include, for example, recording media, computer memory, read-only memory, optoelectric and / or electric carrier signals, telecommunication signals, and software distribution packages. Depending on the processing power required, the computer program may be executed on a single electronic digital computer or distributed across multiple computers. The computer-readable medium or computer-readable storage medium may be a non-transient medium.

[0099] In other exemplary embodiments, the function may be performed by hardware or circuits included in the device (e.g., device (10) or device (20)) using, for example, an application-specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software. In yet another exemplary embodiment, the function may be implemented by intangible means that can be carried out by a signal, namely an electromagnetic signal downloaded from the Internet or another network.

[0100] According to certain exemplary embodiments, a device such as a node, device, or corresponding component may be composed of a circuit, a computer or microprocessor, such as a single-chip computer element, or a chipset comprising at least a memory for providing storage capacity used for arithmetic operations and an arithmetic processor for executing arithmetic operations.

[0101] A person skilled in the art will readily understand that the exemplary disclosures discussed above may be implemented in different sequences of procedures and / or with hardware elements of configurations different from those disclosed. Therefore, although the present disclosure has been described based on these exemplary embodiments, it will be apparent to a person skilled in the art that certain modifications, variations, and alternative configurations will be apparent within the spirit and scope of the exemplary embodiments. While the above embodiments refer to 5G NR and LTE technologies, the above embodiments may also apply to any other current or future 3GPP technologies, such as LTE-Advanced and / or 4th generation (4G) technology. Explanation of the symbols

[0102] 3GPP 3rd Generation Partnership Project 5G 5th generation 5GCN 5G Core Network 5GS 5G System BS Base Station DL Download Link eNB Enhanced Node B gNB 5G or next-generation NodeB ID identifier IE information elements IIoT Industrial Internet of Things IUC vs. UE coordination LMF location management function LTE Long Term Evolution NR New Wireless Access NW network PRS Positioning Reference Signal RSRP reference signal reception power RSS-based synchronization source RSTD reference signal time difference RTOA relative arrival time RTT round trip time SL Sidelink TDOA arrival time difference TRP Transmit / Receive Point UE User Equipment UL Uplink UWB Ultra-Wideband V2X Vehicle-to-All WI Task Item

Claims

Claim 1 A device comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code, when executed by the at least one processor, the device comprises: receiving one or more messages from one or more devices of a set of selected devices, each of the one or more messages comprising synchronization information; selecting at least one device of a set of selected devices for a positioning communication session based on the synchronization information; selecting a set of selected devices from a set of multiple devices; transmitting a request for synchronization information from the set of selected devices to one or more devices of the set of selected devices, wherein the selection of the set of devices is performed prior to transmitting the request for synchronization information; and storing instructions for performing a positioning estimation of the device based on positioning signals received through a positioning communication session from at least one device of the set of selected devices. Claim 2 The device according to claim 1, wherein the synchronization information comprises: identifiers of one or more devices of a set of selected devices and one or more other devices of a set of selected devices that are mutually synchronized with one or more devices different from the set of selected devices; identifiers of one or more other devices of a set of selected devices; a synchronization level between one or more devices of a set of selected devices and one or more other devices of a set of selected devices and one or more devices different from the set of selected devices; a synchronization level between one or more devices of a set of selected devices and one or more other devices of a set of selected devices and one or more devices different from the set of selected devices; an indication that one or more devices of a set of selected devices use the same synchronization reference source as one or more other devices of a set of selected devices and one or more devices different from the set of selected devices, or at least one indication of the reliability of the synchronization. Claim 3 A device according to claim 1, wherein positioning signals received from at least one device of a set of selected devices include a positioning reference signal. Claim 4 A device according to any one of claims 1 to 3, wherein the synchronization information includes at least synchronization state support information indicating a synchronization level threshold. Claim 5 A device according to any one of claims 1 to 3, wherein positioning signals are received from at least one device of a set of selected devices through one or both of a sidelink interface and a wireless interface. Claim 6 In any one of claims 1 to 3, the synchronization information is: a device transmitted from one of a network node, peer anchor user equipment, or a global navigation satellite system. Claim 7 In any one of claims 1 to 3, the set of selected devices includes anchor user equipment, and the device is target user equipment. Claim 8 A device comprising at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to store commands such that, when executed by the at least one processor, the device receives a request for synchronization information from a device; performs a synchronization state evaluation with one or more devices of a set of devices in accordance with the received request; transmits one or more messages to the device based on the synchronization state evaluation, each of the one or more messages including synchronization information; receives a request to establish a positioning session based on the synchronization information; and performs positioning with the device in response to the request to establish a positioning session. Claim 9 In claim 8, the performance of the synchronization state evaluation comprises: coordinating with one or more other devices of a set of devices regarding a positioning synchronization state; receiving positioning signals from one or more other devices of a set of devices; calculating a signal transmission time based on location knowledge of one or more devices of a set of devices; and estimating synchronization accuracy by considering positioning reference signal transmission failures, or communicating with a positioning reference point and requesting synchronization information from one or more other devices of a set of devices, the device. Claim 10 In claim 8, the performance of the synchronization state evaluation comprises: estimating the synchronization positioning reference signal drift of the device by comparing it with the device's synchronization reference source or positioning reference point. Claim 11 A device according to any one of claims 8 to 10, wherein the synchronization information comprises: identifiers of one or more other devices of a set of devices that are mutually synchronized with one or more devices of a set of devices; identifiers of one or more other devices of a set of devices; a synchronization level between one or more devices of a set of devices and one or more other devices of a set of devices; a synchronization level between one or more devices of a set of devices and one or more other devices of a set of devices; an indication that one or more devices of a set of devices use the same synchronization reference source as one or more other devices of a set of devices; or at least one indication of the reliability of the synchronization. Claim 12 A device according to any one of claims 8 to 10, wherein the synchronization information includes at least synchronization state support information indicating a synchronization level threshold. Claim 13 In any one of claims 8 through 10, the synchronization information is: a device transmitted from one of a network node, peer anchor user equipment, or a global navigation satellite system. Claim 14 In claim 9, the device, and one or both of one or more other devices of the set of devices, comprise an anchor user device, wherein the device is a target user device. Claim 15 delete

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