Node synchronization status information to facilitate sensing in a wireless network

Abstract

Embodiments include methods performed by a first node of a wireless network to facilitate sensing in the wireless network. Such methods include receiving, from a second node of the wireless network, synchronization status information (SSI) associated with the second node or with a third node of the wireless network. Such methods include, based on the received SSI, performing one or more operations to facilitate sensing in the wireless network. Other embodiments include complementary methods performed by the second node, as well as node apparatus configured to perform such methods.

Description

[0001] NODE SYNCHRONIZATION STATUS INFORMATION TO FACILITATE SENSING IN A WIRELESS NETWORK

[0002] TECHNICAL FIELD

[0003] The present disclosure relates generally to wireless networks, and more specifically to techniques for determining timing, frequency, and / or phrase synchronization status of various nodes in a wireless network, and using such information to facilitate sensing operations in the wireless network (e.g., integrated sensing and communications).

[0004] BACKGROUND

[0005] Currently the fifth generation (“5G”) of cellular systems - also referred to as New Radio (NR) - is being standardized within the Third-Generation Partnership Project (3GPP). 5G / NR is developed for maximum flexibility to support multiple and substantially different use cases. These include enhanced mobile broadband (eMBB), machine type communications (MTC), ultra-reliable low latency communications (URLLC), side-link device-to-device (D2D), and several other use cases. 5G / NR was initially specified in Release 15 (Rel-15) and continues to evolve through subsequent releases.

[0006] 3 GPP standards provide various ways for positioning (e.g., determining the position of, locating, and / or determining the location of) user equipment (UEs) operating in 3GPP networks. In general, a positioning node configures a target device (e.g., UE) and / or a radio access network (RAN) node to perform one or more positioning measurements according to one or more positioning methods. For example, the positioning measurements can include timing (and / or timing difference) measurements on UE, RAN, and / or satellite transmissions, such as RAN- transmitted positioning reference signals (PRS), The positioning measurements are used by the target device, the RAN node, and / or the positioning node to determine the location of the target device.

[0007] 3GPP TR 22.837 (vl9.4.0) specifies use cases and requirements for enhancement of the 5G system to provide sensing services that address various verticals and / or applications such as autonomous / assisted driving, vehicle-to-everything (V2X) communications, unmanned aerial vehicles (UAVs), three-dimensional (3D) map reconstruction, smart cities / homes / factories, healthcare, and maritime. In this context, the general goal of sensing is to detect and localize a target that is not necessarily connected to the network, such as a pedestrian, an animal, an object, etc. This integration of sensing into 5G (and later-generation) networks is often referred to as joint communications and sensing (JCAS) or Integrated Sensing and Communication (IS AC).

[0008] Sensing involves the network transmitting radio signals and receiving / measuring versions of those signals that have been reflected by the target (and possibly other surroundings). The transmitting and receiving can be performed by the same node(s) or by different node(s). Processing output of the sensing measurements yields information of the target and its surroundings that the radio signals interacted with, possibly including sources of attenuation, reflection, refraction, etc.

[0009] A sensing request may originate from applications internal or external to the network. 3 GPP has defined a Sensing Management Function (SeMF) to handle these requests and to trigger the necessary sensing operations in the RAN, including any UEs that have capability to assist with the sensing. SeMF is a logical entity that resides in the RAN (e.g., gNB) or in 5GC (e.g., a NF). 3GPP has also defined sensing units (SUs, also called sensing radio units, SRUs) to perform radio signal transmission, reception, and / or measurement for sensing operations in the RAN. SUs can be standalone or integrated with another RAN node (including sharing of antennas). A sensing operation may involve multiple SUs, which are selected and configured by SeMF.

[0010] 3GPP has also defined a sensing processing function (SPF) to receive and process SU measurements to obtain one or more sensing results, which the SPF may provide to an SeMF. The SPF can be a separate entity, integrated in a network node (including SeMF), or distributed over multiple network nodes. Upon receiving results from SPF, the SeMF can provide them to the originator of the corresponding sensing request.

[0011] SUMMARY

[0012] To manage sensing operations, an SeMF needs to know whether the involved SUs (or RAN nodes hosting them) are sufficiently synchronized to perform the relevant sensing operations. 5G / NR and fourth-generation Long-Term Evolution (4G / LTE) networks offer various techniques for time synchronization between RAN nodes and for reporting of time synchronization characteristics to other entities. Even so, these techniques are inadequate for ISAC applications that will require inter-SU synchronization in time, frequency, and phase. Thus, new techniques are needed.

[0013] An object of embodiments of the present disclosure is to improve ISAC operation in RANs, such as by providing, enabling, and / or facilitating solutions to exemplary problems summarized above and described in more detail below.

[0014] Embodiments include methods e.g., procedures) performed by a first node of a wireless network to facilitate sensing in the wireless network.

[0015] These exemplary methods include receiving, from a second node of the wireless network, synchronization status information (SSI) associated with the second node or with a third node of the wireless network. These exemplary methods also include, based on the received SSI, performing one or more operations to facilitate sensing in the wireless network In some embodiments, these exemplary methods also include sending to the second node a request to report SSI. The SSI is received in accordance with the request. In other embodiments, the SSI is received in response to condition for reporting SSI being fulfilled at the second node.

[0016] Various examples of operations performed by the first node, based on the received SSI, to facilitate sensing in the wireless network are disclosed herein.

[0017] In some embodiments, these exemplary methods also include receiving from a fourth node a request for a sensing operation in the wireless network. The operations to facilitate sensing may be further based on the request for a sensing operation.

[0018] Other embodiments include exemplary methods (e.g., procedures) performed by a second node of a wireless network to facilitate sensing in the wireless network. These embodiments are generally complementary to first node embodiments summarized above.

[0019] These exemplary methods include obtaining SSI associated with the second node or with a third node of the wireless network. These exemplary methods also include sending the SSI to a first node of the wireless network.

[0020] In some embodiments, these exemplary methods also include receiving from the first node a request to report SSI. The SSI is sent in accordance with the request. In other embodiments, the SSI is sent in response to determining that one or more parameters of the obtained SSI fulfills a condition for SSI reporting.

[0021] In various embodiments summarized above, the SSI sent by the second node and received by the first node may include one or more of the following information associated with the second node or with the third node:

[0022] • synchronization state;

[0023] • indication or level of overall synchronization in time, frequency, and phase;

[0024] • time synchronization error;

[0025] • frequency synchronization error

[0026] • phase synchronization error;

[0027] • compensation for time, frequency, and / or phase synchronization errors;

[0028] • traceability of synchronization to universal time coordinate (UTC);

[0029] • traceability of synchronization to global navigation satellite system (GNSS);

[0030] • synchronization source;

[0031] • synchronization offset with respect to a reference node in the wireless network;

[0032] • reference time for synchronization;

[0033] • transmission and / or reception timing characteristics;

[0034] • local clock accuracy; • local clock frequency stability or drift;

[0035] • local clock offset from UTC;

[0036] • radio interface subframe number (SFN) offset;

[0037] • antenna alignment or orientation;

[0038] • synchronization-related capabilities;

[0039] • fulfillment of a first condition that triggers SSI reporting;

[0040] • fulfillment of a second condition that triggers resynchronization; and

[0041] • a synchronization-related command or request.

[0042] In various embodiments summarized above, the request for SSI sent by the first node and received by the second node includes or identifies one or more of the following:

[0043] • one or more SSI parameters of interest;

[0044] • respective ranges of interest for the one or more SSI parameters of interest;

[0045] • a first condition for reporting the one or more SSI parameters of interest;

[0046] • one or more network resources of interest for SSI;

[0047] • an SSI reporting configuration; and

[0048] • a second condition for initiating or requesting resynchronization of the second node and / or the third node.

[0049] In various embodiments summarized above, the first node is one of the following: a RAN node, an SU, an SRU, an SeMF, and an SPF. Also, the second node is one of the following: a second RAN node, a second SU, a UE, an LMF, and an operations / administration / maintenance (OAM) node. In some embodiments, the SSI is associated with the third node, which is one of the following: a third RAN node, a third SU, and a second UE.

[0050] Other embodiments include node apparatus configured to perform operations corresponding to any of the exemplary methods summarized above. Other embodiments include non-transitory, computer-readable media storing program instructions that, when executed by processing circuitry, configure such nodes to perform operations corresponding to any of the exemplary methods summarized above.

[0051] These and other embodiments described herein can provide various benefits and / or advantages. For example, knowledge of synchronization status of other sensing nodes may enable an SeMF to select appropriate sensing nodes for bistatic sensing. As another example, knowledge of synchronization status may improve accuracy of sensing results based on reducing, eliminating, and / or compensating for synchronization errors / differences among involved sensing nodes. Similar improvements can be obtained when combining results from concurrent monostatic sensing operations by multiple sensing nodes. In this case, the multiple results may be combined coherently based on knowledge of synchronization status, thereby improving resolution and / or accuracy.

[0052] These and other objects, features, and advantages of embodiments of the present disclosure will become apparent upon reading the following Detailed Description in view of the Drawings briefly described below.

[0053] BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 shows a high-level view of an exemplary 5G / NR network architecture.

[0055] Figure 2 shows an exemplary configuration of 5G / NR user plane (UP) and control plane (CP) protocol stacks.

[0056] Figure 3 illustrates a high-level architecture for positioning in NR networks.

[0057] Figure 4 illustrates various sensing techniques that can be used in a 5G network to detect and / or localize a target (e.g., pedestrian).

[0058] Figure 5 illustrates a high-level architecture for ISAC and positioning in 5G / NR networks.

[0059] Figure 6 shows an exemplary procedure for 5GC monitoring of gNB timing synchronization.

[0060] Figures 7-8 show two exemplary procedures for UE monitoring of gNB timing synchronization.

[0061] Figures 9-10 show signaling diagrams of two SSI reporting procedures according to various embodiments of the present disclosure.

[0062] Figure 11 shows a flow diagram of an exemplary method (e.g., procedure) for a first node, according to various embodiments of the present disclosure.

[0063] Figure 12 shows a flow diagram of an exemplary method (e.g., procedure) for a second node, according to various embodiments of the present disclosure.

[0064] Figure 13 shows a communication system according to some embodiments of the present disclosure.

[0065] Figure 14 shows a UE according to various embodiments of the present disclosure.

[0066] Figure 15 shows a network node according to some embodiments of the present disclosure.

[0067] Figure 16 shows a virtualization environment in which functions implemented by some embodiments of the present disclosure may be virtualized.

[0068] DETAILED DESCRIPTION

[0069] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0070] In general, all terms used herein are to be interpreted according to their ordinary meaning to a person of ordinary skill in the relevant technical field, unless a different meaning is expressly defined and / or implied from the context of use. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise or clearly implied from the context of use. The operations of any methods and / or procedures disclosed herein do not have to be performed in the exact order disclosed, unless an operation is explicitly described as following or preceding another operation and / or where it is implicit that an operation must follow or precede another operation. Any feature of any embodiment disclosed herein can apply to any other disclosed embodiment, as appropriate. Likewise, any advantage of any embodiment described herein can apply to any other disclosed embodiment, as appropriate.

[0071] Furthermore, the following terms are used throughout the description given below:

[0072] • Radio Access Node: As used herein, a “radio access node” (or equivalently “radio network node,” “radio access network node,” or “RAN node”) can be any node in a radio access network (RAN) that operates to wirelessly transmit and / or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., gNB in a 5G / NR network or eNB in a LTE network), base station distributed components (e.g., CU and DU), a high-power or macro base station, a low-power base station (e.g., micro, pico, femto, or home base station, or the like), an integrated access backhaul (IAB) node, a transmission point (TP), a transmission reception point (TRP), a remote radio unit (RRU or RRH), and a relay node.

[0073] • Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a serving gateway (SGW), a PDN Gateway (P-GW), a Policy and Charging Rules Function (PCRF), an access and mobility management function (AMF), a session management function (SMF), a user plane function (UPF), a Charging Function (CHF), a Policy Control Function (PCF), an Authentication Server Function (AUSF), a location management function (LMF), or the like.

[0074] • Wireless Device: As used herein, a “wireless device” (or “WD” for short) is any type of device that is capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other wireless devices. Communicating wirelessly can involve transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information through air. Unless otherwise noted, the term “wireless device” is used interchangeably herein with the term “user equipment” (or “UE” for short), with both of these terms having a different meaning than the term “network node”.

[0075] • Network Node: As used herein, a “network node” is any node that is either part of a radio access network (e.g., a radio access node or equivalent term) or of a core network (e.g., a core network node) of a cellular communications network. Functionally, a network node is equipment capable, configured, arranged, and / or operable to communicate directly or indirectly with a wireless device and / or with other network nodes or equipment in the cellular communications network, to enable and / or provide wireless access to the wireless device, and / or to perform other functions (e.g., administration) in the cellular communications network.

[0076] • Base station: As used herein, a “base station” may comprise a physical or a logical node transmitting or controlling the transmission of radio signals, e.g., eNB, gNB, ng-eNB, en- gNB, centralized unit (CU) / distributed unit (DU), transmitting radio network node, transmission point (TP), transmission reception point (TRP), remote radio head (RRH), remote radio unit (RRU), Distributed Antenna System (DAS), relay, etc.

[0077] • Node: As used herein, the term “node” (without prefix) can be any type of node that can operate in or with a wireless network (including RAN and / or core network), including a radio access node (or equivalent term), core network node, or wireless device. However, the term “node” may be limited to a particular type (e.g., radio access node) based on its specific characteristics in any given context.

[0078] The above definitions are not meant to be exclusive. In other words, various ones of the above terms may be explained and / or described elsewhere in the present disclosure using the same or similar terminology. Nevertheless, to the extent that such other explanations and / or descriptions conflict with the above definitions, the above definitions should control.

[0079] Note that the description given herein focuses on a 3 GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system. Furthermore, although the term “cell” is used herein, it should be understood that (particularly with respect to 5G NR) beams may be used instead of cells and, as such, concepts described herein apply equally to both cells and beams.

[0080] Figure 1 illustrates a high-level view of an exemplary 5G network architecture, consisting of a Next Generation Radio Access Network (NG-RAN, 199) and a 5G Core Network (5GC, 198). As shown in the figure, the NG-RAN can include gNBs (e.g, 110a, b) and ng-eNBs (e.g, 120a, b) that are interconnected with each other via respective Xn interfaces. The gNBs and ng-eNBs are also connected via NG interfaces to the 5GC, more specifically to access and mobility management functions (AMFs, e.g., 130a, b) via respective NG-C interfaces and to user plane functions (UPFs, e.g., 140a, b) via respective NG-U interfaces. Moreover, the AMFs can communicate with one or more policy control functions (PCFs, e.g., 150a,b) and network exposure functions (NEFs, e.g., 160a, b) in the 5GC.

[0081] The radio technology for the NG-RAN is often referred to as “New Radio” (NR). Each of the gNBs can support the NR radio interface including frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof. Each of ng-eNBs can support the fourth generation (4G) Long-Term Evolution (LTE) radio interface. Each of the gNBs and ng-eNBs can serve a geographic coverage area including one or more cells (e.g., l l la-b and 121a-b). Depending on the cell in which it is located, a user equipment (LIE, e.g., 105) can communicate with the gNB or ng-eNB serving that cell via the NR or LTE radio interface, respectively. Although Figure 1 shows gNBs and ng-eNBs separately, it is also possible that a single NG-RAN node provides both LTE and NR functionality.

[0082] NG RAN logical nodes (e.g., gNBs 1 lOa-b) may include a Central Unit (CU) and one or more Distributed Units (DUs). CUs are logical nodes that host higher-layer protocols and perform various gNB functions such controlling the operation of DUs. DUs are decentralized logical nodes that host lower layer protocols and can include, depending on the functional split option, various subsets of the gNB functions. A CU connects to one or more associated DUs over respective Fl logical interfaces. Each CU and DU can include various circuitry needed to perform their respective functions, including processing circuitry, communication interface circuitry e.g., transceivers), and power supply circuitry.

[0083] Figure 2 shows an exemplary configuration of NR user plane (UP) and control plane (CP) protocol stacks between a UE (210), a gNB (220), and an AMF (230), such as those shown in Figures 1-2. The Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP) layers between the UE and the gNB are common to UP and CP. PDCP provides ciphering / deciphering, integrity protection, sequence numbering, reordering, and duplicate detection for both CP and UP. In addition, PDCP provides header compression and retransmission for UP data.

[0084] On the UP side, Internet protocol (IP) packets arrive to PDCP as service data units (SDUs), and PDCP creates protocol data units (PDUs) to deliver to RLC. The Service Data Adaptation Protocol (SDAP) layer handles quality-of-service (QoS) including mapping between QoS flows and Data Radio Bearers (DRBs) and marking QoS flow identifiers (QFI) in UL and DL packets.

[0085] When each IP packet arrives, PDCP starts a discard timer. When this timer expires, PDCP discards the associated SDU and the corresponding PDU. If the PDU was delivered to RLC, PDCP also indicates the discard to RLC. The RLC layer transfers PDCP PDUs to the MAC through logical channels (LCH). RLC provides error detection / correction, concatenation, segmentation / reassembly, sequence numbering, reordering of data transferred to / from the upper layers. If RLC receives a discard indication from associated with a PDCP PDU, it will discard the corresponding RLC SDU (or any segment thereof) if it has not been sent to lower layers.

[0086] MAC provides mapping between LCHs and PHY transport channels, LCH prioritization, multiplexing into or demultiplexing from transport blocks (TBs), hybrid ARQ (HARQ) error correction, and dynamic scheduling (in gNB). PHY provides transport channel services to MAC and handles transfer over the NR radio interface, e.g., via modulation, coding, antenna mapping, and beam forming.

[0087] On the CP side, the non-access stratum (NAS) layer between UE and AMF handles UE / gNB authentication, mobility management, and security control. RRC sits below NAS in the UE but terminates in the gNB rather than the AMF. RRC controls communications between UE and gNB at the radio interface as well as the mobility of a UE between cells in the NG-RAN. RRC also broadcasts system information (SI) and performs establishment, configuration, maintenance, and release of DRBs and Signaling Radio Bearers (SRBs) and used by UEs. Additionally, RRC controls addition, modification, and release of carrier aggregation (CA) and dual -connectivity (DC) configurations for UEs, and performs various security functions such as key management.

[0088] After a UE is powered ON it will be in the RRC IDLE state until an RRC connection is established with the network, at which time the UE will transition to RRC_CONNECTED state (e.g., where data transfer can occur). The UE returns to RRC IDLE after the connection with the network is released. In RRC IDLE state, the UE s radio is active on a discontinuous reception (DRX) schedule configured by upper layers. During DRX active periods (also referred to as “DRX On durations"’), an RRC IDLE, UE receives SI broadcast in the cell where the UE is camping, performs measurements of neighbor cells to support cell reselection, and monitors a paging channel on PDCCH for pages from 5GC via gNB, An NR UE in RRC IDLE, state is not known to the gNB serving the cell where the UE is camping. However, NR RRC includes an RRC_INACTIVE state in which a UE is known (e.g., via UE context) by the serving gNB. RRC INACTIVE has some properties similar to a “suspended” condition used in LTE.

[0089] In addition to providing coverage via cells as in LTE, gNBs also provide coverage via “beams.” In general, a downlink (DL, i.e., network to UE) “beam” is a coverage area of a network- transmitted reference signal (RS) that may be measured or monitored by a UE. In NR, for example, RS can include any of the following: synchronization signal / PBCH block (SSB), channel state information RS (CSLRS), tertiary reference signals (or any other sync signal), positioning RS (PRS), demodulation RS (DMRS), phase-tracking reference signals (PTRS), etc. In general, SSB is available to all UEs regardless of the state of their connection with the network, while other RS (e.g., CSI-RS, DM-RS, PTRS) are associated with specific UEs that have a network connection.

[0090] Figure 3 is a block diagram illustrating a high-level architecture for supporting UE positioning in NR networks. NG-RAN (320) can include nodes such as gNBs (e.g., 322) and ng-eNBs (e.g., 321). Each ng-eNB may control one or more transmission points (TPs), such as remote radio heads. Similarly, each gNB may control one or more transmission / reception points (TRPs).

[0091] In addition, the NG-RAN nodes communicate with an AMF (330) in the 5GC via respective NG-C interfaces, while the AMF communicates with a location management function (LMF, 340) via an NLs interface. The LMF supports various functions related to UE positioning, including location determination for a UE, obtaining DL location measurements or a location estimate from the UE, obtaining UL location measurements from the NG RAN, and obtaining non-UE associated assistance data from the NG RAN.

[0092] In addition, positioning-related communication between UEs (e.g., 210) and NG-RAN nodes occurs via the RRC protocol, while positioning-related communication between NG-RAN nodes and LMF occurs via an NRPPa protocol. Optionally, the LMF can also communicate with an enhanced serving mobile location center (E-SMLC, 350) and a secure user plane location platform (SLP, 360) in an LTE network.

[0093] In a typical operation, the AMF can receive a request for a location service associated with a particular target UE from another entity (e.g., a gateway mobile location center, GMLC), or the AMF can initiate a location service on behalf of a particular target UE (e.g., for an emergency call by the UE). The AMF then sends a location services (LS) request to the LMF. The LMF processes the LS request, which may include transferring assistance data to the target UE to assist with UE- based and / or UE-assisted positioning; and / or positioning of the target UE. The LMF then returns the result of the LS (e.g., a position estimate for the UE and / or an indication of any assistance data transferred to the UE) to the AMF or to another entity (e.g., GMLC) that requested the LS.

[0094] 3GPP TR 22.837 (vl9.4.0) specifies use cases and requirements for enhancement of the 5G system to provide sensing services that address various verticals and / or applications such as autonomous / assisted driving, V2X communications, UAVs, 3D map reconstruction, smart cities / homes / factories, healthcare, and maritime. In this context, the general goal of sensing is to detect and localize a target that is not necessarily connected to the network, such as a pedestrian, an animal, an object, etc. This integration of sensing into 5G (and later-generation) networks is often referred to as joint communications and sensing (JCAS) or Integrated Sensing and Communication (ISAC). Sensing involves the network transmitting radio signals and receiving / measuring versions of those signals that have been reflected by the target (and possibly other surroundings). The transmitting and receiving can be performed by the same node(s) or by different node(s). In general, a goal is to detect and localize a non-connected and / or passive target such as a pedestrian, animal, object, etc. However, sensing targets may include connected UEs such that sensing can be used to improve communication-based positioning of such UEs.

[0095] Figure 4 illustrates various sensing techniques that can be used in a 5G network to detect and / or localize a target (e.g., pedestrian). In the upper left, mono-static sensing involves the same node (or antenna) transmitting the sensing signals and receiving / measuring the versions reflected by the target. In the upper right, a first type of bi-static sensing involves a first RAN node transmitting the sensing signals and a second RAN node at a different location receiving / measuring the reflected versions. In the bottom left, a second type of bi-static sensing involves a RAN node transmitting the sensing signals and a UE (or SU) at a different location receiving / measuring the reflected versions. In the bottom right, a third type of bi-static sensing involves a UE (or SU) transmitting the sensing signals and a RAN node at a different location receiving / measuring the reflected versions. Although not shown in Figure 4, multi-static sensing involves multiple nodes at different locations transmitting sensing signals and multiple nodes at different locations receiving / measuring the reflected versions.

[0096] In any of these cases, the receiver may perform one or more of the following sensing measurements on the received sensing signals:

[0097] • Timing measurement (e.g., round-trip time, TOA, Rx-Tx time difference, etc.) of the signal (time when signal was sent + time when the reflected signal was received by the sender)

[0098] • Signal strength, signal quality, signal-to-noise ratio, etc.

[0099] • Phase measurement;

[0100] • Channel impulse response, multipath characteristics, power delay profile;

[0101] • Delay spread, Doppler spectra, Doppler spread, Doppler shift, Doppler frequency,

[0102] • Velocity, Angle of arrival, angle of departure.

[0103] These various measurements can be processed to obtain information about the target and its surroundings that affected the transmitted sensing signals, including one or more of the following:

[0104] • Characteristics (shape, size, number, etc.) of target and / or obstacles ;

[0105] • Velocity of target and / or obstacles;

[0106] • Weather conditions (e.g., rain);

[0107] • Recognition of objects (e.g., wall, blocker, scatterer, etc.). As mentioned above, a sensing target may be a passive object that is unable to communicate with the 5G network but whose presence / position / characteristic needs to be determined. In most cases, the passive object is moving or at least is able to move, such as when the passive object is a vehicle without subscriber identity module (SIM), a person without a UE, an animal, etc. Movement of the passive object enables it to be differentiated from other static objects in the same environment such as walls, buildings, structures, etc.

[0108] A sensing request may originate from applications internal or external to the network. 3 GPP has defined a Sensing Management Function (SeMF) to handle these requests and to trigger the necessary sensing operations in the RAN, including any UEs that have capability to assist with the sensing. SeMF is a logical entity that resides in the RAN (e.g., gNB) or in 5GC (e.g., a NF). 3GPP has also defined SUs to perform radio signal transmission, reception, and / or measurement for sensing operations in the RAN. SUs can be standalone or integrated with another RAN node (including sharing of antennas).

[0109] For example, SeMF can be a sensing server that sends to the RAN a request to trigger a sensing session, sensing measurements, etc. The sensing session is configured based at least on sensing task, sensing target information (e.g., object type, weather condition, etc.), and / or sensing area information (e.g., forest, indoor factory, house, area size, etc.). The SeMF may select a set of SUs to perform sensing measurements, which may include RF sensors and non-RF sensors (e.g. cameras, motion sensors, heat sensors, etc.). Example measurements include raw samples, radio measurements, timing measurements, velocity, temperature, sensing event indication such as weather change or motion pattern change, etc.

[0110] 3GPP has also defined a sensing processing function (SPF) to receive and process SU measurements to obtain one or more sensing results, which the SPF may provide to an SeMF. The SPF can be a separate entity, integrated in a network node (including SeMF), or distributed over multiple network nodes. Upon receiving results from SPF, the SeMF can provide them to the originator of the corresponding sensing request.

[0111] Figure 5 illustrates a high-level architecture for ISAC and positioning in 5G / NR networks. In particular, Figure 5 illustrates how SeMF, SPF, and SUs defined for sensing operations may be integrated into the exemplary 5G positioning architecture shown in Figure 3. In the ISAC architecture shown in Figure 5, each of gNB (522), ng-eNB (521), and UE (510) includes an optional SU (511, respectively 511a, 511b, and 511c). In addition, SeMF (530) communications with the LMF via a Cl interface, with the AMF via a C2 interface, and with SPF (540) via an 12 interface. In addition, the SPF communicates with NG-RAN (520) via an II interface. Although not shown in Figure 5, the ISAC architecture in 5G / NR networks may also include one or more synchronization reference units (SRUs). Each SRU has access to an absolute synchronization source (e.g., GNSS) and can be used as a synchronization source for other nodes. For example, an SRU can be (or be included in) a RAN node (e.g., gNB) or a UE.

[0112] 3GPP networks utilize various techniques for time synchronization of RAN nodes. For example, 4G / LTE networks utilize radio-interface based synchronization (RIBS) in which an eNB can maintain time synchronization based on monitoring RS transmitted by another eNB. Network operations / administration / maintenance (OAM) function configures the eNBs with available RS information such as pattern, periodicity, and offset, and coordinates mapping of different eNBs to different stratum levels. Each increase in stratum level represents another separation from master clock source (e.g., GNSS). To increase hearability of RS for synchronization, listening eNBs may request other eNBs to mute their transmissions of interfering RS.

[0113] RIBS is not used in 5G / NR networks. Instead, a Time Sensitive Communication and Time. Synchronization Function (TSCTSF) in the 5GC may receive timing synchronization status from various gNBs via AMF. Each gNB detects timing synchronization degradation or improvement locally and informs the TSCTSF. Additionally, each gNB may also provide clock quality information to the UEs that it serves.

[0114] Figure 6 shows an exemplary procedure for 5GC monitoring of gNB timing synchronization. The gNB in this example includes a CU and a DU. In operation 0, the DU may be pre-configured with thresholds for various timing synchronization status (TSS) attributes via OAM. Such TSS attributes may include synchronization state, traceability to universal time coordinate (UTC), traceability to GNSS, clock frequency stability, clock accuracy, parent time source, and possibly other attributes defined in 3GPP TS 23.501. When the thresholds are met or exceeded, events will be triggered (e.g., operation 7) and the DU reports Timing Synchronization Status to AMF via the CU (e.g., operations 8-9). Alternately, the CU may receive a request for TSS information from the AMF, based on which it queries the DU and receives a corresponding response and report, and provides these to the AMF (e.g. operations 1-6).

[0115] Figure 7 shows an exemplary procedure for UE monitoring of gNB timing synchronization. The gNB in this example includes a CU and a DU. In operation 1, the gNB receives clock quality reporting control information for a UE, e.g., from an AMF in an INITIAL CONTEXXT SETUP REQUEST message. In operation 2, the gNB responds with an appropriate message, e.g., an INITIAL CONTEXXT SETUP RESPONSE. The clock quality reporting control information may include clock quality detail level (i.e., "metrics" or "acceptable / not acceptable indication") and clock quality acceptance criteria for the UE (i.e., if the clock quality detail level equals "acceptable / not acceptable indication"). Based on the clock quality reporting control information, the gNB determines what clock quality information to provide to the UE. For example, if the clock quality detail level equals "clock quality metrics", the gNB provides clock quality metrics (i.e., ones supported the gNB) to the UE. This may include one or more of TSS attributes mentioned above in relation to Figure 6. On the other hand, if the clock quality detail level equals "acceptable / not acceptable indication", the gNB indicates “acceptable” to the UE if the gNB's timing synchronization status matches the acceptance criteria received from the AMF; otherwise, the gNB indicates “not acceptable.” For UEs in RRC CONNECTED state, the gNB uses unicast RRC signaling (e.g., DLInfoTransfer message) to provide an event ID and the determined clock quality information.

[0116] Figure 8 shows an exemplary procedure for UE monitoring of gNB timing synchronization, particularly for UEs not in RRC CONNECTED state. In this case, the UE first needs to set up or resume its RRC connection to receive the clock quality information from the gNB via the unicast RRC signaling. When time synchronization status of the gNB changes (e.g., operation 0), the gNB broadcasts in SIB9 an event ID that informs UEs about its time synchronization status (e.g., operation 1).

[0117] In operation 2, a UE in RRC INACTIVE or RRC IDLE determines if there is clock quality information update available at the gNB based on the received SIB9 information. If there is a time synchronization status update available, the UEs RRC layer indicates this to the UE’s NAS, which may request the UE’s RRC layer to setup (i.e., from RRC IDLE) or resume (i.e., from RRC INACTIVE) the UE’s RRC connection with the gNB in operation 3. In operations 4- 5, the gNB determines which clock quality information should be reported to the UE (e.g., metrics or "acceptable / not acceptable") and sends this information via unicast RRC signaling.

[0118] To manage sensing operations, an SeMF needs to know whether the involved SUs (or RAN nodes hosting them) are sufficiently synchronized to perform the relevant sensing operations. The above-described time synchronization techniques used in 5G / NR and 4G / LTE networks are inadequate for ISAC applications such as distributed MIMO (D-MIMO) and carrier phase positioning (CPP), which inter-SU synchronization in time, frequency, and phase. Thus, new techniques are needed.

[0119] Embodiments of the present disclosure address these and other problems, issues, and / or difficulties by techniques for a first sensing node (e.g., SeMF, SU, RAN node, etc.) to request a second node to start or stop reporting of timing, frequency, and phase synchronization status information (SSI), and for the second node to receive the request and provide the requested SSI accordingly. The SSI can be associated with the second node or with a third node. Alternately, the first node can provide the second node with one or more conditions that, when fulfilled, cause the second node to provide SSI to the first node. Upon receiving the SSI, the first node may use it for various operations such as compensating sensing measurements for delays due to synchronization mismatch. These techniques may be applicable for wireless integrated sensing and communication (ISAC) networks, such as in conjunction with 5G and / or 6G networks.

[0120] Embodiments can provide various benefits and / or advantages. For example, knowledge of synchronization status of other sensing nodes may enable an SeMF to select appropriate sensing nodes for the bistatic sensing. As another example, knowledge of synchronization status may improve accuracy of sensing results based on reducing, eliminating, and / or compensating for synchronization errors / differences among involved sensing nodes. Similar improvements can be obtained when combining results from concurrent monostatic sensing operations by multiple sensing nodes. In this case, the multiple results may be combined coherently based on knowledge of synchronization status, thereby improving resolution and / or accuracy.

[0121] In some embodiments, a first node (e.g., SeMF, SU, RAN node) sends to a second node (e.g., SeMF, SU, RAN node) a request to start or stop reporting of timing, frequency, and / or phase SSI (which also may be referred to as “sensing SSI”). In various embodiments, the request may include or identify one or more of the following:

[0122] • one or more specific SSI parameters of interest;

[0123] • range(s) of interest for one or more SSI parameters of interest;

[0124] • a condition (e.g., event, threshold, etc.) associated with one or more SSI parameters of interest;

[0125] • one or more network resources (e.g., cells, beams, TRPs, antenna reference points, etc.) of interest for SSI;

[0126] • an SSI reporting configuration, which may include a reporting periodicity, a reporting start time, a reporting trigger condition or event, a sensing QoS requirement, specific SSI parameters to be reported, etc.; and

[0127] • a further condition (e.g., event, threshold, etc.) for triggering a resynchronization and / or a request (e.g., alarm) for resynchronization.

[0128] Subsequently, the second node provides SSI to the first node in accordance with the request. For example, if the request includes one or more specific SSI parameters of interest and a condition (e.g., threshold XI) associated with one or more SSI parameters of interest, the second node reports the requested parameters of interest when the condition is fulfilled (e.g., by the parameters of interest). As another example, if the request includes one or more specific SSI parameters of interest and a reporting configuration with a reporting start time and periodicity, the second node reports the requested SSI parameters initially at the reporting start time and at subsequent times corresponding to the periodicity. In some embodiments, the second node can also send an acknowledgement of the request, e.g., separate from the SSI report itself. This acknowledgement may be beneficial when the request includes an SSI reporting condition that may be fulfilled at some unknown later time. In some embodiments, when the first node initially requests the second node to report SSI (e.g., with a periodicity), the first node later sends a further request for the second node to stop the reporting of SSI, with which the second node complies.

[0129] In other embodiments, the second node may provide SSI to the first node independent of any request, such as in response to a triggering condition (e.g., a change or update in SSI, a change triggering the need to update the SSI, a synchronization characteristic changes with respect to a threshold, a mobility-related change such as a cell change), a rule, expiration of a periodic or aperiodic timer, etc.

[0130] In some embodiments, the second node’s reporting of SSI may be adaptive based on change in relevant synchronization characteristics. For example, the second node may adapt its reporting periodicity and / or granularity based on rate of change (drift rate) of its own synchronization status or another node’s synchronization status. The second node’s reporting may also be adaptive based on a sensing QoS requirement (e.g., for an application) received from the first RAN node.

[0131] In some embodiments, the reported SSI can be associated with the second node. The following are some examples of these embodiments:

[0132] • first node = SU1, second node = SU2.

[0133] • first node = SU, second node = RAN node that provides time, frequency, and / or phase reference to assist the SU in synchronization.

[0134] • first node = RAN node, second node = SU.

[0135] • first node = SeMF, second node = SU.

[0136] • first node = SeMF, second node = RAN node.

[0137] • first node = SRU, second node = SU (e.g., SU sending SSI to obtain synchronization reference, assistance, and / or command from SRU).

[0138] • first node = SU, second node = SRU (e.g., SRU controlling or assisting in synchronization of SU).

[0139] In other embodiments, the reported SSI can be associated with a third node different than the second node. The following are some examples of these embodiments:

[0140] • first node = SU1, second node =SeMF, and third node = SU1, other SU, RAN node, or UE. As a more specific example, an SeMF may provide SSI associated with the third node that enables SU1 to synchronize with the third node and / or a command to adjust one or more sync-related parameters in SU1. • first node =SeMF or SPF, second node = LMF, and third node = SU, RAN node, or UE.

[0141] • first node =SeMF or SPF, second node = OAM node, and third node = SU, RAN node, or UE.

[0142] • first node =SeMF or SPF, second node = RAN node, and third node = SU, other RAN node, or UE.

[0143] • first node = SU1 or SPF, second node = SeMF or OAM, and third node = SU2 or SRU.

[0144] Upon receiving the SSI from the second node, the first node may perform various operations based on the SSI, including one of more of the following:

[0145] • sending the SSI to another node;

[0146] • generating assistance information for an SU to receive radio signals to be used for sensing measurements, and providing the assistance information to the SU;

[0147] • performing sensing measurements on radio signals;

[0148] • transmitting one or more radio signals for sensing by other nodes;

[0149] • selecting one or more SUs to perform sensing measurements on received radio signals;

[0150] • selecting one or more SUs to transmit radio signals for sensing measurements (e.g., by the receiving SUs), which for the case of bistatic sensing may be done in conjunction with the selection of the receiving SUs;

[0151] • grouping of SUs by SSI similarity, e.g., first group of SUs with same or similar SSI and a second group of SUs with SSI that is the same or similar but different from the SSI associated with the first group;

[0152] • grouping of SUs by synchronization source, e.g., for participating in the same sensing operation or task;

[0153] • excluding one or more SUs from participating in a sensing operation or task, e.g., based on SSI for such SUs not fulfilling a threshold requirement;

[0154] • discarding or reducing weight of measurements received from one or more SUs, e.g., e.g., based on SSI for such SUs not fulfilling a threshold requirement;

[0155] • selecting a sensing method to be used for a sensing operation or task, e.g., a more accurate sensing method when the SSI indicates better synchronization;

[0156] • determining whether a target QoS for a requested sensing operation or task can be fulfilled (e.g., based on SSI vs. some threshold);

[0157] • sending to a requesting node an indication of whether the target QoS for the requested sensing operation or task can be fulfilled (e.g., a negative indication when SSI is worse than the threshold);

[0158] • initiating synchronization of one or more nodes (e.g., first, second, third), which may include one or more of the following operations: o updating a synchronization reference of the first node; o adjusting timing of radio signals transmitted or received by the first node; o sending a synchronization reference signal and / or a synchronization command to the second node and / or to the third node; o controlling adjustment of signal transmission or reception by the second node and / or the third node;

[0159] • determining quality of a previously obtained sensing result, e.g., based on SSI of the SUs involved in measurements on which the sensing result is based;

[0160] • determining amount of compensation needed for a previously obtained sensing measurement or result, e.g., to reduce or remove error due to synchronization inaccuracy or misalignment;

[0161] • applying compensation indicated by or determined from the SSI to a previously obtained sensing measurement or result;

[0162] • sending to OAM a notification of a synchronization failure, e.g., when SSI indicates synchronization error is beyond some threshold.

[0163] In various embodiments, the SSI provided by the second node to the first node can include or indicate one or more of the following information:

[0164] • time / frequency / phase synchronization state (e.g., locked, holdover, or free running);

[0165] • time synchronization error (e.g., resolution of 25 ns);

[0166] • frequency synchronization error (e.g., range of + / -5ppm with resolution 0. Ippm);

[0167] • phase synchronization error (e.g., range of 0-2K radians or 0-359 degrees);

[0168] • indication or level of overall synchronization in time, frequency, and phase;

[0169] • compensation for time, frequency, and / or phase synchronization error;

[0170] • time / frequency / phase synchronization drift model(s);

[0171] • traceability of synchronization to UTC (e.g., yes / no, stratum level);

[0172] • traceability of synchronization to GNSS (e.g., yes / no, stratum level);

[0173] • source(s) or reference(s) for timing, frequency, and / or phase synchronization, such as GNSS, RAN node, SRU, SU, radio resource (e.g., carrier, cell, beam), transport network, Precision Time Protocol (PTP), Network Time Protocol (NTP), handset (e.g., wireless device / UE), atomic clock, etc.;

[0174] • time, frequency, and / or phase synchronization offset with respect to a reference node (e.g., delay in symbols / timeslots / subframes, frequency shit, phase shift, etc.);

[0175] • reference time for timing, frequency, and / or phase synchronization (e.g., UTC or radio interface event such as subframe number (SFN), function of SFN, slot number, etc.); • transmission and / or reception timing characteristics (e.g., receive time difference (RTD), maximum receive time difference (MRTD), transmit time difference (TTD), maximum transmit time difference (MTTD), time alignment error (TAE), timing advance (TA), etc.);

[0176] • local clock accuracy;

[0177] • local clock frequency stability or drift;

[0178] • local time offset (e.g., from UTC);

[0179] • subframe number (SFN) offset;

[0180] • antenna alignment / orientation (e.g., to support Carrier Phase Positioning);

[0181] • synchronization-related capabilities (e.g., supported accuracy, maximum drift, error limit, minimum timing resolution, etc.);

[0182] • a synchronization-related condition (e.g., threshold, target value, target range, etc.) whose fulfillment triggered reporting of the SSI; and

[0183] • a synchronization-related command or request (e.g., to adjust transmission timing, frequency, and / or phase).

[0184] More generally, the SSI can include any parameter(s), characteristic(s), estimate(s), or indication(s) related to timing, frequency, and / or phase synchronization or alignment. For example, the SSI can include synchronization assistance data that facilitates receiving and / or performing a sensing-related measurement.

[0185] The SSI can provided from the second node to the first node in various forms according to differing embodiments. The following are some illustrative examples:

[0186] • absolute values of relevant information, e.g., the current or most recent values.

[0187] • relative to corresponding values that were previously provided;

[0188] • relative to corresponding values associated with another (e.g., reference) node; and

[0189] • one or more statistics of values over a relevant time period (e.g., maximum, minimum, mean, median, standard deviation, confidence level, confidence interval, etc.).

[0190] Figure 9 shows a signaling diagram of an SSI reporting procedure according to some embodiments of the present disclosure. The procedure may be applicable to wireless ISAC networks, such as in conjunction with 5G and / or 6G networks. The procedure involves a first SU (SU1, 910), a second SU (SU2, 920), and an SeMF (930). Although the operations of Figure 9 are given numerical labels, this is done to facilitate the following explanation rather than to imply or require any particular operational order, unless expressly stated otherwise.

[0191] In operation 1, the SeMF sends to SU1 a request to start or stop reporting of time, frequency, and / or phase synchronization information, which corresponds to the SSI discussed above. In operation 2, SU1 sends a message confirming the start or stop of reporting in accordance with the request. In case the request is to start reporting, in operation 3 SU1 sends a report of SSI to the SeMF in accordance the request in operation 1. For example, the report may include one or more SSI parameters of interest as indicated in the request.

[0192] In operation 4, the SeMF selects one or more sensing nodes to perform a sensing operation or task. For example, the SeMF may select SU1 based on the reported SSI. The sensing operation or task may be associated with a task ID and / or an SeMF ID. In operation 5, the SeMF sends the SSI reported by SU1 (or assistance information derived therefrom) to SU2. Putting operations 1- 5 in the context of more generic embodiments described above, the SeMF performs operations attributed to the first node while SU1 performs operations attributed to the second node.

[0193] In operation 6, SU 1 sends to SU2 a request to start or stop reporting of time, frequency, and / or phase synchronization information, which corresponds to the SSI discussed above. In operation 7, SU2 sends a message confirming the start or stop of reporting in accordance with the request. In case the request is to start reporting, in operation 8 SU2 sends a report of SSI to SU1 in accordance the request in operation 6. For example, the report may include one or more SSI parameters of interest as indicated in the request.

[0194] In operation 9, SU1 selects one or more sensing nodes to perform a sensing operation or task. For example, SU1 may select SU2 based on the reported SSI. The sensing operation or task may be associated with a task ID and / or an SeMF ID. In operation 10, SU1 sends the SSI reported by SU2 (or assistance information derived therefrom) to the SeMF. Putting operations 6-10 in the context of more generic embodiments described above, SU1 performs operations attributed to the first node while SU2 performs operations attributed to the second node.

[0195] Figure 10 shows a signaling diagram of an SSI reporting procedure according to other embodiments of the present disclosure. The procedure may be applicable to wireless ISAC networks, such as in conjunction with 5G and / or 6G networks. The procedure involves a first SU (SU1, 910), a second SU (SU2, 920), and an SPF (940). Although the operations of Figure 10 are given numerical labels, this is done to facilitate the following explanation rather than to imply or require any particular operational order, unless expressly stated otherwise.

[0196] In operation 1, SU2 detects a change in relevant SSI values, which may be associated with SU2 or with another SU (e.g., SU1). For example, the detected change may be greater than a preconfigured threshold or any change that may affect performance of a sensing operation or task. Based on this detected change, SU2 sends a report of SSI to SU1 (operation 2) and the SPF (operation 3). Note that these reports are independent of any SSI reporting requests from these nodes. Upon receiving the SSI from SU2, the SPF uses it for processing of sensing measurements provided by SU2, such as for delay compensation. Although not shown, SU1 may use SSI received from SU2 for various purposes, such as sensing measurements of signals transmitted by SU1. Some embodiments may be realized as 3 GPP specification text that describes messages and / or procedures. The messages and / or procedures may be applicable to wireless ISAC networks, such as in conjunction with 5G and / or 6G networks. The example 3GPP specification text below provides definitions of some inter-node messages that may contain SSI-related information described above for other embodiments.

[0197] *** Begin exemplary 3 GPP specification text ***

[0198] SSI STATUS REQUEST

[0199] This message is sent by the first node to request the second node to start or stop reporting of sensing synchronization status information.

[0200] Direction: First node Second node

[0201] SSI STATUS RESPONSE

[0202] This message is sent by the second node to confirm the request to start or stop reporting of sensing synchronization status information.

[0203] Direction: Second node First node

[0204] SSI STATUS FAILURE

[0205] This message is sent by the second node to indicate that reporting of sensing synchronisation status information cannot be initiated.

[0206] Direction: Second node First node

[0207] SSI STATUS REPORT

[0208] This message is sent by the second node to report previously requested sensing synchronisation status information.

[0209] Direction: Second node First node

[0210] SensingSSI Information Element (IE)

[0211] *** End exemplary 3 GPP specification text *** Various features of the embodiments described above correspond to various operations illustrated in Figures 11-12, which show exemplary methods (e.g., procedures) for a first node and a second node, respectively. In other words, various features of the operations described below correspond to various embodiments described above. Furthermore, the exemplary methods shown in Figures 11-12 can be used cooperatively to provide various benefits, advantages, and / or solutions to problems described herein. Although Figures 11-12 show specific blocks in particular orders, the operations of the exemplary methods can be performed in different orders than shown and can be combined and / or divided into blocks having different functionality than shown. Optional blocks or operations are indicated by dashed lines.

[0212] In particular, Figure 11 shows an exemplary method (e.g., procedure) for a first node to facilitate sensing in a wireless network, according to various embodiments of the present disclosure. The exemplary method can be performed by any appropriate node (e.g., UE, RAN node, SU, SRU, SPF, SeMF, etc.) such as described elsewhere herein.

[0213] The exemplary method includes the operations of block 1130, where the first node receives, from a second node of the wireless network, synchronization status information (SSI) associated with the second node or with a third node of the wireless network. The exemplary method also includes the operations of block 1160, where based on the received SSI, the first node performs one or more operations to facilitate sensing in the wireless network.

[0214] In some embodiments, the exemplary method also includes the operations of block 1110, where the first node sends to the second node a request to report SSI. The SSI is received in block 1130 in accordance with the request. In some of these embodiments, the request includes or identifies one or more of the following:

[0215] • one or more SSI parameters of interest;

[0216] • respective ranges of interest for the one or more SSI parameters of interest;

[0217] • a first condition for reporting the one or more SSI parameters of interest;

[0218] • one or more network resources of interest for SSI;

[0219] • an SSI reporting configuration; and

[0220] • a second condition for initiating or requesting resynchronization of the second node and / or the third node.

[0221] In some variants of these embodiments, the SSI reporting configuration includes one or more of the following: a periodicity for periodic SSI reporting, a start time for periodic SSI reporting, a trigger condition for aperiodic SSI reporting, and a sensing quality-of-service (QoS) requirement. In some variants of these embodiments, the one or more network resources of interest include any of the following: one or more cells, one or more beams, one or more transmission reception points (TRPs), and one or more antenna reference points (ARPs). In some of these embodiments, after receiving the SSI in one or more reports in block 1130, the exemplary method also includes the operations of block 1140, where the first node sends to the second node a further request to stop reporting SSI. In other of these embodiments, before receiving the SSI in one or more reports in block 1130, the exemplary method also includes the operations of block 1120, where the first node receives from the second node an acknowledgement of the request in block 1110.

[0222] In other embodiments, the SSI is received in response to condition for reporting SSI being fulfilled at the second node.

[0223] In some embodiments, the received SSI includes or indicates one or more of the following information associated with the second node or with the third node:

[0224] • synchronization state;

[0225] • indication or level of overall synchronization in time, frequency, and phase;

[0226] • time synchronization error;

[0227] • frequency synchronization error

[0228] • phase synchronization error;

[0229] • compensation for time, frequency, and / or phase synchronization errors;

[0230] • traceability of synchronization to universal time coordinate (UTC);

[0231] • traceability of synchronization to global navigation satellite system (GNSS);

[0232] • synchronization source;

[0233] • synchronization offset with respect to a reference node in the wireless network;

[0234] • reference time for synchronization;

[0235] • transmission and / or reception timing characteristics;

[0236] • local clock accuracy;

[0237] • local clock frequency stability or drift;

[0238] • local clock offset from UTC;

[0239] • radio interface subframe number (SFN) offset;

[0240] • antenna alignment or orientation;

[0241] • synchronization-related capabilities;

[0242] • fulfillment of a first condition that triggers SSI reporting;

[0243] • fulfillment of a second condition that triggers resynchronization; and

[0244] • a synchronization-related command or request.

[0245] Various specific examples of the information in the above list were discussed above.

[0246] In some of these embodiments, the indicated synchronization source is one of the following: GNSS, a transport network, Precision Time Protocol (PTP), Network Time Protocol (NTP), atomic clock, or a node or radio resource in the wireless network. In some variants of these embodiments, the indicated synchronization source is one of the following nodes or radio resources in the wireless network: radio access network (RAN) node, synchronization reference unit (SRU), sensing unit (SU), user equipment (UE), carrier, cell, or beam.

[0247] In some of these embodiments, the synchronization-related capabilities include one or more of the following: synchronization adjustment resolution, minimum synchronization accuracy, maximum synchronization error, maximum synchronization drift, and synchronization drift model.

[0248] In some embodiments, the one or more operations in block 1160 based on the received SSI include one or more of the following, labelled with corresponding sub-block numbers:

[0249] • (1160a) sending the received SSI to one or more other nodes in the wireless network;

[0250] • (1160b) selecting one or more sensing units (SUs) in the wireless network to participate in sensing measurements;

[0251] • (1160c) generating assistance information for one or more SUs in the wireless network to perform sensing measurements on radio signals transmitted by the node associated with the received SSI (i.e., the second or third node), and sending the assistance information to the one or more SUs;

[0252] • (1160d) performing sensing measurements on radio signals transmitted by the node associated with the received SSI; and

[0253] • (1160e) transmitting one or more radio signals for sensing measurements by the node associated with the received SSI.

[0254] In some of these embodiments, selecting the one or more SUs based on the received SSI in sub-block 1160b includes one or more of the following operations:

[0255] • selecting one or more first SUs to transmit radio signals for sensing measurements; and

[0256] • selecting one or more second SUs to perform sensing measurements on received radio signals.

[0257] The node associated with the received SSI is selected to be at least one of the following: one of the first SUs, and one of the second SUs.

[0258] In some variants of these embodiments, the node associated with the received SSI is selected based on the received SSI including one or more parameters in common with further SSI associated with at least one of the following: other selected first SUs, and other selected second SUs. In some further variants, the one or more parameters in common include a synchronization source.

[0259] In some embodiments, the exemplary method also includes the operations of block 1150, where the first node receives from a fourth node a request for a sensing operation in the wireless network. In such case, the one or more operations performed in block 1160 based on the received SSI include one or more of the following, labelled with corresponding sub-block numbers:

[0260] • (1160f) selecting a sensing method to be used for the sensing operation, based on a synchronization state, quality, or accuracy indicated by the received SSI;

[0261] • (1160g) selecting or excluding the node associated with the received SSI for participating as a sensing unit (SU) in the sensing operation;

[0262] • (1160h) determining use, weighting, and / or compensation of measurements, for the sensing operation, that were performed by the node associated with the received SSI; and

[0263] • (1160i) determining quality and / or compensation of a sensing result, for the sensing operation, that is based on measurements performed by the node associated with the received SSI.

[0264] In some of these embodiments, the request for the sensing operation indicates a target quality-of-service (QoS), and the one or more operations performed in block 1160 based on the received SSI also include one or more of the following, labelled with corresponding sub-block numbers:

[0265] • (1160j) determining whether the target QoS for the sensing operation can be fulfilled; and

[0266] • (1160k) sending to the fourth node an indication of whether the target QoS for the sensing operation can be fulfilled.

[0267] In other embodiments, the one or more operations performed in block 1160 based on the received SSI include one or more of the following synchronization-related operations, labelled with corresponding sub-block numbers:

[0268] • (1160m) updating a synchronization reference of the first node;

[0269] • (1160n) adjusting timing, frequency, and / or phase of radio signal transmission and / or reception by the first node;

[0270] • (1160p) initiating adjustment of timing, frequency, and / or phase of radio signal transmission and / or reception by the node associated with the SSI;

[0271] • (1160q) transmitting a synchronization reference signal to the node associated with the SSI; and

[0272] • (1160r) sending, to an operations / administration / maintenance (0AM) node of the wireless network, an indication of synchronization failure of the node associated with the SSI. In some of these embodiments, the one or more synchronization-related operations are performed based on one of the following in the SSI: a synchronization command or request, an indication that a condition for triggering resynchronization has been fulfilled.

[0273] In some embodiments, the first node is one of the following: a RAN node, an SU, an SRU, an SeMF, and an SPF. Also, the second node is one of the following: a second RAN node, a second SU, a UE, an LMF, and an operations / administration / maintenance (OAM) node. Various specific combinations of one of these first nodes and one of these second nodes were given above, but in general any useful combination may be employed. In some of these embodiments, the SSI is associated with the third node, which is one of the following: a third RAN node, a third SU, and a second UE.

[0274] In addition, Figure 12 shows an exemplary method (e.g., procedure) for a second node to facilitate sensing in a wireless network, according to various embodiments of the present disclosure. The exemplary method can be performed by any appropriate node (e.g., UE, RAN node, SU, SRU, SPF, SeMF, etc.) such as described elsewhere herein.

[0275] The exemplary method includes the operations of block 1210, where the second node obtains SSI associated with the second node or with a third node of the wireless network. The exemplary method also includes the operations of block 1250, where the second node sends the SSI to a first node of the wireless network.

[0276] In some embodiments, the exemplary method also includes the operations of block 1220, where the second node receives from the first node a request to report SSI. The SSI is sent in block 1250 in accordance with the request. In various embodiments, the request may include or identify any of the corresponding information described above in relation to first node embodiments.

[0277] In some of these embodiments, after sending the SSI in one or more reports in block 1250, the exemplary method also includes the operations of block 1260, where the second node receives from the first node a further request to stop reporting SSI. For example, the second node may stop SSI reporting upon receive of the further request. In some of these embodiments, before sending the SSI in one or more reports in block 1250, the exemplary method also includes the operations of block 1230, where the second node sends to the first node an acknowledgement of the request in block 1220.

[0278] In other embodiments, the SSI is sent in response to the operations of block 1240, where the second node determines that one or more parameters of the obtained SSI fulfills a condition for SSI reporting.

[0279] In various embodiments, the SSI may include or indicate any of the corresponding information described above in relation to first node embodiments. In some embodiments, the first node is one of the following: a RAN node, an SU, an SRU, an SeMF, and an SPF. Also, the second node is one of the following: a second RAN node, a second SU, a UE, an LMF, and an OAM node. Various specific combinations of one of these first nodes and one of these second nodes were given above, but in general any useful combination may be employed. In some of these embodiments, the SSI is associated with the third node, which is one of the following: a third RAN node, a third SU, and a second UE.

[0280] Although various embodiments are described above in terms of methods, techniques, and / or procedures, the person of ordinary skill will readily comprehend that such methods, techniques, and / or procedures can be embodied by various combinations of hardware and software in various systems, communication devices, computing devices, control devices, apparatuses, non-transitory computer-readable media, computer program products, etc.

[0281] Figure 13 shows an example of a communication system 1300 in accordance with some embodiments. In this example, communication system 1300 includes a telecommunication network 1302 that includes an access network 1304 (e.g., RAN) and a core network 1306, which includes one or more core network nodes 1308. Access network 1304 includes one or more access network nodes, such as network nodes 13 lOa-b (one or more of which may be generally referred to as network nodes 1310), or any other similar 3GPP access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, telecommunication network 1302 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in telecommunication network 1302 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in telecommunication network 1302, including one or more network nodes 1310 and / or core network nodes 1308.

[0282] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU- CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an 0-2 interface defined by the 0-RAN Alliance or comparable technologies. Network nodes 1310 facilitate direct or indirect connection of UEs, such as by connecting UEs 1312a-d (one or more of which may be generally referred to as UEs 1312) to core network 1306 over one or more wireless connections.

[0283] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, communication system 1300 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. Communication system 1300 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0284] UEs 1312 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with network nodes 1310 and other communication devices. Similarly, network nodes 1310 are arranged, capable, configured, and / or operable to communicate directly or indirectly with UEs 1312 and / or with other network nodes or equipment in telecommunication network 1302 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in telecommunication network 1302.

[0285] In the depicted example, core network 1306 connects network nodes 1310 to one or more hosts, such as host 1316. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. Core network 1306 includes one or more core network nodes (e.g., 1308) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of core network node 1308. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0286] Host 1316 may be under the ownership or control of a service provider other than an operator or provider of access network 1304 and / or telecommunication network 1302, and may be operated by the service provider or on behalf of the service provider. Host 1316 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0287] As a whole, communication system 1300 of Figure 13 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0288] In some examples, telecommunication network 1302 is a cellular network that implements 3 GPP standardized features. Accordingly, telecommunication network 1302 may support network slicing to provide different logical networks to different devices that are connected to telecommunication network 1302. For example, telecommunication network 1302 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive loT services to yet further UEs.

[0289] In some examples, UEs 1312 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to access network 1304 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from access network 1304. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0290] In some embodiments, any of UEs 1312 and network nodes 1310 may be configured to perform operations attributed to a first node in various embodiments described above, including the exemplary method shown in Figure 11. Likewise, in some embodiments, any of UEs 1312 and network nodes 1310 can be configured to perform operations attributed to a second node in various embodiments described above, including the exemplary method shown in Figure 12.

[0291] In the example, hub 1314 communicates with access network 1304 to facilitate indirect communication between one or more UEs (e.g., 1312c and / or 1312d) and network nodes (e.g., 1310b). In some examples, hub 1314 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, hub 1314 may be a broadband router enabling access to core network 1306 for the UEs. As another example, hub 1314 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 1310, or by executable code, script, process, or other instructions in hub 1314. As another example, hub 1314 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, hub 1314 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, hub 1314 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which hub 1314 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, hub 1314 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0292] Hub 1314 may have a constant / persistent or intermittent connection to network node 1310b. Hub 1314 may also allow for a different communication scheme and / or schedule between hub 1314 and UEs (e.g., 1312c and / or 1312d), and between hub 1314 and core network 1306. In other examples, hub 1314 is connected to core network 1306 and / or one or more UEs via a wired connection. Moreover, hub 1314 may be configured to connect to an M2M service provider over access network 1304 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with network nodes 1310 while still connected via hub 1314 via a wired or wireless connection. In some embodiments, hub 1314 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to network node 1310b. In other embodiments, hub 1314 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1310b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0293] Figure 14 shows a UE 1400 in accordance with some embodiments. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by 3 GPP, including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0294] A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0295] UE 1400 includes processing circuitry 1402 that is operatively coupled via a bus 1404 to an input / output interface 1406, a power source 1408, a memory 1410, a communication interface 1412, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 14. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0296] Processing circuitry 1402 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in memory 1410. Processing circuitry 1402 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, processing circuitry 1402 may include multiple central processing units (CPUs). In the example, input / output interface 1406 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into UE 1400. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0297] In some embodiments, power source 1408 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. Power source 1408 may further include power circuitry for delivering power from power source 1408 itself, and / or an external power source, to the various parts of UE 1400 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of power source 1408. Power circuitry may perform any formatting, converting, or other modification to the power from power source 1408 to make the power suitable for the respective components of UE 1400 to which power is supplied.

[0298] Memory 1410 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, memory 1410 includes one or more application programs 1414, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1416. Memory 1410 may store, for use by UE 1400, any of a variety of various operating systems or combinations of operating systems.

[0299] Memory 1410 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ Memory 1410 may allow UE 1400 to access instructions, application programs and the like, stored on transitory or non- transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in memory 1410, which may be or comprise a device-readable storage medium.

[0300] Processing circuitry 1402 may be configured to communicate with an access network or other network using communication interface 1412. Communication interface 1412 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1422. Communication interface 1412 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 1418 and / or a receiver 1420 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, transmitter 1418 and receiver 1420 may be coupled to one or more antennas (e.g., antenna 1422) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0301] In the illustrated embodiment, communication functions of communication interface 1412 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0302] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 1412, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0303] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0304] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to UE 1400 shown in Figure 14.

[0305] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3 GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0306] In some embodiments, UE 1400 may be configured to perform operations attributed to a first node in various embodiments described above, including the exemplary method shown in Figure 11. In other embodiments, UE 1400 may be configured to perform operations attributed to a second node in various embodiments described above, including the exemplary method shown in Figure 12.

[0307] Figure 15 shows a network node 1500 in accordance with some embodiments. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (e.g., radio base stations, Node Bs, eNBs, gNBs), and O-RAN nodes or components of an O-RAN node (e g., O-RU, O-DU, O-CU).

[0308] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0309] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0310] Network node 1500 includes processing circuitry 1502, memory 1504, communication interface 1506, and power source 1508. Network node 1500 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node 1500 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node 1500 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1504 for different RATs) and some components may be reused (e.g., a same antenna 1510 may be shared by different RATs). Network node 1500 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1500, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1500.

[0311] Processing circuitry 1502 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 1500 components, such as memory 1504, to provide network node 1500 functionality.

[0312] In some embodiments, processing circuitry 1502 includes a system on a chip (SOC). In some embodiments, processing circuitry 1502 includes one or more of radio frequency (RF) transceiver circuitry 1512 and baseband processing circuitry 1514. In some embodiments, RF transceiver circuitry 1512 and baseband processing circuitry 1514 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1512 and baseband processing circuitry 1514 may be on the same chip or set of chips, boards, or units.

[0313] Memory 1504 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by processing circuitry 1502. Memory 1504 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions (collectively denoted computer program 1504a, which may be in the form of a computer program product) capable of being executed by processing circuitry 1502 and utilized by network node 1500. Memory 1504 may be used to store any calculations made by processing circuitry 1502 and / or any data received via communication interface 1506. In some embodiments, processing circuitry 1502 and memory 1504 is integrated.

[0314] Communication interface 1506 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, communication interface 1506 comprises port(s) / terminal(s) 1516 to send and receive data, for example to and from a network over a wired connection. Communication interface 1506 also includes radio front- end circuitry 1518 that may be coupled to, or in certain embodiments a part of, antenna 1510. Radio front-end circuitry 1518 comprises filters 1520 and amplifiers 1522. Radio front-end circuitry 1518 may be connected to an antenna 1510 and processing circuitry 1502. The radio front-end circuitry may be configured to condition signals communicated between antenna 1510 and processing circuitry 1502. Radio front-end circuitry 1518 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. Radio front-end circuitry 1518 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1520 and / or amplifiers 1522. The radio signal may then be transmitted via antenna 1510. Similarly, when receiving data, antenna 1510 may collect radio signals which are then converted into digital data by radio front-end circuitry 1518. The digital data may be passed to processing circuitry 1502. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0315] In certain alternative embodiments, network node 1500 does not include separate radio front-end circuitry 1518, instead, processing circuitry 1502 includes radio front-end circuitry and is connected to antenna 1510. Similarly, in some embodiments, all or some of RF transceiver circuitry 1512 is part of communication interface 1506. In still other embodiments, communication interface 1506 includes one or more ports or terminals 1516, radio front-end circuitry 1518, and RF transceiver circuitry 1512, as part of a radio unit (not shown), and communication interface 1506 communicates with baseband processing circuitry 1514, which is part of a digital unit (not shown).

[0316] Antenna 1510 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. Antenna 1510 may be coupled to radio front-end circuitry 1518 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, antenna 1510 is separate from network node 1500 and connectable to network node 1500 through an interface or port.

[0317] Antenna 1510, communication interface 1506, and / or processing circuitry 1502 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, antenna 1510, communication interface 1506, and / or processing circuitry 1502 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0318] Power source 1508 provides power to the various components of network node 1500 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 1508 may further comprise, or be coupled to, power management circuitry to supply the components of network node 1500 with power for performing the functionality described herein. For example, network node 1500 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of power source 1508. As a further example, power source 1508 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0319] Embodiments of network node 1500 may include additional components beyond those shown in Figure 15 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, network node 1500 may include user interface equipment to allow input of information into network node 1500 and to allow output of information from network node 1500. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1500.

[0320] In some embodiments, network node 1500 may be configured to perform operations attributed to a first node in various embodiments described above, including the exemplary method shown in Figure 11. In other embodiments, network node 1500 may be configured to perform operations attributed to a second node in various embodiments described above, including the exemplary method shown in Figure 12.

[0321] Figure 16 is a block diagram illustrating a virtualization environment 1600 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1600 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1600 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface. Applications 1602 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 1600 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein. For example, a virtual node 1602 may be configured to perform operations attributed to a first node in various embodiments described above, including the exemplary method shown in Figure 11. In other embodiments, a virtual node 1602 may be configured to perform operations attributed to a second node in various embodiments described above, including the exemplary method shown in Figure 12.

[0322] Hardware 1604 includes processing circuitry, memory that stores software and / or instructions (collectively denoted computer program 1604a, which may be in the form of a computer program product) executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1606 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1608a-1608b (one or more of which may be generally referred to as VMs 1608), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. Virtualization layer 1606 may present a virtual operating platform that appears like networking hardware to the VMs 1608.

[0323] VMs 1608 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1606. Different embodiments of the instance of a virtual appliance 1602 may be implemented on one or more of VMs 1608, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0324] In the context of NFV, each VM 1608 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each VM 1608, and that part of hardware 1604 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1608 on top of the hardware 1604 and corresponds to the application 1602.

[0325] Hardware 1604 may be implemented in a standalone network node with generic or specific components. Hardware 1604 may implement some functions via virtualization. Alternatively, hardware 1604 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration function 1610, which, among others, oversees lifecycle management of applications 1602. In some embodiments, hardware 1604 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1612 which may alternatively be used for communication between hardware nodes and radio units.

[0326] The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, and procedures that, although not explicitly shown or described herein, embody the principles of the disclosure and can be thus within the spirit and scope of the disclosure. Various exemplary embodiments can be used together with one another, as well as interchangeably therewith, as should be understood by those having ordinary skill in the art.

[0327] The term unit, as used herein, can have conventional meaning in the field of electronics, electrical devices and / or electronic devices and can include, for example, electrical and / or electronic circuitry, devices, modules, processors, memories, logic solid state and / or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and / or displaying functions, and so on, as such as those that are described herein.

[0328] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and / or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

[0329] As described herein, device and / or apparatus can be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device or apparatus, instead of being hardware implemented, be implemented as a software module such as a computer program or a computer program product comprising executable software code portions for execution or being run on a processor. Furthermore, functionality of a device or apparatus can be implemented by any combination of hardware and software. A device or apparatus can also be regarded as an assembly of multiple devices and / or apparatuses, whether functionally in cooperation with or independently of each other. Moreover, devices and apparatuses can be implemented in a distributed fashion throughout a system, so long as the functionality of the device or apparatus is preserved. Such and similar principles are considered as known to a skilled person.

[0330] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0331] In addition, certain terms used in the present disclosure, including the specification and drawings, can be used synonymously in certain instances (e.g., “data” and “information”). It should be understood, that although these terms (and / or other terms that can be synonymous to one another) can be used synonymously herein, there can be instances when such words can be intended to not be used synonymously.

Claims

CLAIMS1. A method performed by a first node of a wireless network to facilitate sensing in the wireless network, the method comprising: receiving (1130), from a second node of the wireless network, synchronization status information, SSI, associated with the second node or with a third node of the wireless network; and based on the received SSI, performing (1160) one or more operations to facilitate sensing in the wireless network.

2. The method of claim 1, further comprising sending (1110) to the second node a request to report SSI, wherein the SSI is received in accordance with the request.

3. The method of claim 2, wherein the request includes or identifies one or more of the following: one or more SSI parameters of interest; respective ranges of interest for the one or more SSI parameters of interest; a first condition for reporting the one or more SSI parameters of interest; one or more network resources of interest for SSI; an SSI reporting configuration; and a second condition for initiating or requesting resynchronization of at least one of the second node and the third node.

4. The method of claim 3, wherein the SSI reporting configuration includes one or more of the following: a periodicity for periodic SSI reporting, a start time for periodic SSI reporting, a trigger condition for aperiodic SSI reporting, and a sensing quality-of-service, QoS, requirement.

5. The method of any of claims 3-4, wherein the one or more network resources of interest include any of the following: one or more cells; one or more beams; one or more transmission reception points, TRPs; and one or more antenna reference points, ARPs.

6. The method of any of claims 2-5, further comprising, after receiving (1130) the SSI in one or more reports, sending (1140) to the second node a further request to stop reporting SSI.

7. The method of any of claims 2-5, further comprising, before receiving (1130) the SSI, receiving (1120) from the second node an acknowledgement of the request.

8. The method of claim 1, wherein the SSI is received in response to condition for reporting SSI being fulfilled at the second node.

9. The method of any of claims 1-8, wherein the received SSI includes or indicates one or more of the following information associated with the second node or with the third node: synchronization state; indication or level of overall synchronization in time, frequency, and phase; time synchronization error; frequency synchronization error phase synchronization error; compensation for time, frequency, and / or phase synchronization errors; traceability of synchronization to universal time coordinate, UTC; traceability of synchronization to global navigation satellite system, GNSS; synchronization source; synchronization offset with respect to a reference node in the wireless network; reference time for synchronization; transmission and / or reception timing characteristics; local clock accuracy; local clock frequency stability or drift; local clock offset from UTC; radio interface subframe number, SFN, offset; antenna alignment or orientation; synchronization-related capabilities; fulfillment of a first condition that triggers SSI reporting; fulfillment of a second condition that triggers resynchronization; and a synchronization-related command or request.

10. The method of claim 9, wherein the indicated synchronization source is one of the following: GNSS; a transport network; Precision Time Protocol, PTP; Network Time Protocol, NTP; atomic clock; or a node or radio resource in the wireless network.

11. The method of claim 10, wherein the indicated synchronization source is one of the following nodes or radio resources in the wireless network: radio access network, RAN, node; synchronization reference unit, SRU; sensing unit, SU; user equipment, UE; carrier; cell; or beam.

12. The method of any of claims 9-11, wherein the synchronization-related capabilities include one or more of the following: synchronization adjustment resolution, minimum synchronization accuracy, maximum synchronization error, maximum synchronization drift, and synchronization drift model.

13. The method of any of claims 1-12, wherein the one or more operations based on the received SSI include one or more of the following: sending (1160a) the received SSI to one or more other nodes in the wireless network; selecting (1160b) one or more sensing units, SUs, in the wireless network to participate in sensing measurements; generating (1160c) assistance information for one or more SUs in the wireless network to perform sensing measurements on radio signals transmitted by the node associated with the received SSI, and sending the assistance information to the one or more SUs; performing (1160d) sensing measurements on radio signals transmitted by the node associated with the received SSI; and transmitting (1160e) one or more radio signals for sensing measurements by the node associated with the received SSI.

14. The method of claim 13, wherein selecting (1160b) the one or more SUs based on the received SSI includes one or more of the following operations: selecting one or more first SUs to transmit radio signals for sensing measurements; and selecting one or more second SUs to perform sensing measurements on received radio signals, wherein the node associated with the received SSI is selected to be at least one of the following: one of the first SUs, and one of the second SUs.

15. The method of claim 14, wherein the node associated with the received SSI is selected based on the received SSI including one or more parameters in common with further SSIassociated with at least one of the following: other selected first SUs, and other selected second SUs.

16. The method of claim 15, wherein the one or more parameters in common include a synchronization source.

17. The method of any of claims 1-12, further comprising receiving (1150) from a fourth node a request for a sensing operation in the wireless network, wherein the one or more operations performed based on the received SSI include one or more of the following selecting (1160f) a sensing method to be used for the sensing operation, based on a synchronization state, quality, or accuracy indicated by the received SSI; selecting or excluding (1160g) the node associated with the received SSI for participating as a sensing unit, SU, in the sensing operation; determining (1160h) use, weighting, and / or compensation of measurements, for the sensing operation, that were performed by the node associated with the received SSI; and determining (1160i) quality and / or compensation of a sensing result, for the sensing operation, that is based on measurements performed by the node associated with the received SSI.

18. The method of claim 17, wherein the request for the sensing operation indicates a target quality-of-service, QoS, and the one or more operations performed based on the received SSI also include: determining (1160j) whether the target QoS for the sensing operation can be fulfilled; and sending (1160k) to the fourth node an indication of whether the target QoS for the sensing operation can be fulfilled.

19. The method of any of claims 1-12, wherein the one or more operations performed based on the received SSI include one or more of the following synchronization-related operations: updating (1160m) a synchronization reference of the first node; adjusting (1160n) timing, frequency, and / or phase of radio signal transmission and / or reception by the first node; initiating (1160p) adjustment of timing, frequency, and / or phase of radio signal transmission and / or reception by the node associated with the SSI;transmitting (1160q) a synchronization reference signal to the node associated with the SSI; and sending (1160r), to an operations / administration / maintenance, OAM, node of the wireless network, an indication of synchronization failure of the node associated with the SSI.

20. The method of claim 19, wherein the one or more synchronization-related operations are performed based on one of the following in the SSI: a synchronization command or request, an indication that a condition for triggering resynchronization has been fulfilled.

21. The method of any of claims 1-19, wherein: the first node is one of the following: a radio access network, RAN, node; a sensing unit, SU; a sensing reference unit, SRU; a sensing management function, SeMF; and a sensing processing function, SPF; and the second node is one of the following: a second RAN node; a second SU; a user equipment, UE; a location management function, LMF; and an operations / administration / maintenance, OAM, node.

22. The method of claim 21, wherein the SSI is associated with the third node, which is one of the following: a third RAN node, a third SU, and a second UE.

23. A method performed by a second node of a wireless network to facilitate sensing in the wireless network, the method comprising: obtaining (1210) synchronization status information, SSI, associated with the second node or with a third node of the wireless network; and sending (1250) the SSI to a first node of the wireless network.

24. The method of claim 23, further comprising receiving (1220) from the first node a request to report SSI, wherein the SSI is sent in accordance with the request.

25. The method of claim 24, wherein the request includes or identifies one or more of the following: one or more SSI parameters of interest; respective ranges of interest for the one or more SSI parameters of interest; a first condition for reporting the one or more SSI parameters of interest;one or more network resources of interest for SSI; an SSI reporting configuration; and a second condition for initiating or requesting resynchronization of at least one of the second node and the third node.

26. The method of claim 25, wherein the SSI reporting configuration includes one or more of the following: a periodicity for periodic SSI reporting, a start time for periodic SSI reporting, a trigger condition for aperiodic SSI reporting, and a sensing quality-of-service, QoS, requirement.

27. The method of any of claims 25-26, wherein the one or more network resources of interest include any of the following: one or more cells; one or more beams; one or more transmission reception points, TRPs; and one or more antenna reference points, ARPs.

28. The method of any of claims 24-27, further comprising, after sending (1250) the SSI in one or more reports, receiving (1260) from the first node a further request to stop reporting SSI.

29. The method of any of claims 24-27, further comprising, before sending (1250) the SSI, sending (1230) to the first node an acknowledgement of the request.

30. The method of claim 23, wherein the SSI is sent in response to determining (1240) that one or more parameters of the obtained SSI fulfills a condition for SSI reporting.

31. The method of any of embodiments 23-30, wherein the SSI includes or indicates one or more of the following information associated with the second node or with the third node: synchronization state; indication or level of overall synchronization in time, frequency, and phase; time synchronization error; frequency synchronization error phase synchronization error; compensation for time, frequency, and / or phase synchronization errors; traceability of synchronization to universal time coordinate, UTC; traceability of synchronization to global navigation satellite system, GNSS; synchronization source; synchronization offset with respect to a reference node in the wireless network; reference time for synchronization;transmission and / or reception timing characteristics; local clock accuracy; local clock frequency stability or drift; local clock offset from UTC; radio interface subframe number, SFN, offset; antenna alignment or orientation; synchronization-related capabilities; fulfillment of a first condition that triggers SSI reporting; fulfillment of a second condition that triggers resynchronization; and a synchronization-related command or request.

32. The method of claim 31, wherein the indicated synchronization source is one of the following: GNSS; a transport network; Precision Time Protocol, PTP; Network Time Protocol, NTP; atomic clock; or a node or radio resource in the wireless network.

33. The method of claim 32, wherein the indicated synchronization source is one of the following nodes or radio resources in the wireless network: radio access network, RAN, node; synchronization reference unit, SRU; sensing unit, SU; user equipment, UE; carrier; cell; or beam.

34. The method of any of claims 31-33, wherein the synchronization-related capabilities include one or more of the following: synchronization adjustment resolution, minimum synchronization accuracy, maximum synchronization error, maximum synchronization drift, and synchronization drift model.

35. The method of any of claims 23-34, wherein: the first node is one of the following: a radio access network, RAN, node; a sensing unit, SU; a sensing reference unit, SRU; a sensing management function, SeMF; and a sensing processing function, SPF; and the second node is one of the following: a second RAN node; a second SU; a user equipment, UE; a location management function, LMF; and an operations / administration / maintenance, OAM, node.

36. The method of claim 35, wherein the SSI is associated with the third node, which is one of the following: a third RAN node, a third SU, and a second UE.

37. A first node (511, 530, 540, 910, 930, 940, 1310, 1312, 1400, 1500, 1602) configured to facilitate sensing in a wireless network (520, 1304), the first node comprising: communication interface circuitry (1412, 1506, 1604) arranged to communicate with a second node (511, 530, 910, 920, 930, 1310, 1312, 1400, 1500, 1602) of the wireless network; and processing circuitry (1402, 1502, 1604) operably coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to: receive, from the second node, synchronization status information, SSI, associated with the second node or with a third node of the wireless network; and based on the received SSI, perform one or more operations to facilitate sensing in the wireless network.

38. The first node of claim 37, wherein the processing circuitry and the communication interface circuitry are further configured to perform operations corresponding to any of the methods of claims 2-22.

39. A first node (511, 530, 540, 910, 930, 940, 1310, 1312, 1400, 1500, 1602) configured to facilitate sensing in a wireless network (520, 1304), the first node being further configured to: receive, from a second node of the wireless network, synchronization status information, SSI, associated with the second node or with a third node of the wireless network; and based on the received SSI, perform one or more operations to facilitate sensing in the wireless network.

40. The first node of claim 39, being further configured to perform operations corresponding to any of the methods of claims 2-22.

41. A non-transitory, computer-readable medium (1410, 1504, 1604) storing computerexecutable instructions that, when executed by processing circuitry (1402, 1502, 1604) of a first node (511, 530, 540, 910, 930, 940, 1310, 1312, 1400, 1500, 1602) configured to facilitate sensing in a wireless network (520, 1304), configure the first node to perform operations corresponding to any of the methods of claims 1-22.

42. A computer program product (1414, 1504a, 1604a) comprising computer-executable instructions that, when executed by processing circuitry (1402, 1502, 1604) of a first node (511, 530, 540, 910, 930, 940, 1310, 1312, 1400, 1500, 1602) configured to facilitate sensing in a wireless network (520, 1304), configure the first node to perform operations corresponding to any of the methods of claims 1-22.

43. A second node (511, 530, 910, 920, 930, 1310, 1312, 1400, 1500, 1602) configured to facilitate sensing in a wireless network (520, 1304), the second node comprising: communication interface circuitry (1412, 1506, 1604) arranged to communicate with at least a first node (511, 530, 540, 910, 930, 940, 1310, 1312, 1400, 1500, 1602) of the wireless network; and processing circuitry (1402, 1502, 1604) operably coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to: obtain synchronization status information, SSI, associated with the second node or with a third node of the wireless network; and send the SSI to the first node.

44. The second node of claim 43, wherein the processing circuitry and the communication interface circuitry are further configured to perform operations corresponding to any of the methods of claims 24-36.

45. A second node (511, 530, 910, 920, 930, 1310, 1312, 1400, 1500, 1602) configured to facilitate sensing in a wireless network (520, 1304), the second node being further configured to: obtain synchronization status information, SSI, associated with the second node or with a third node of the wireless network; and send the SSI to a first node of the wireless network.

46. The second node of claim 45, being further configured to perform operations corresponding to any of the methods of claims 24-36.

47. A non-transitory, computer-readable medium (1410, 1504, 1604) storing computerexecutable instructions that, when executed by processing circuitry (1402, 1502, 1604) of a second node (511, 530, 910, 920, 930, 1310, 1312, 1400, 1500, 1602) configured to facilitatesensing in a wireless network (520, 1304), configure the second node to perform operations corresponding to any of the methods of claims 23-26.

48. A computer program product (1414, 1504a, 1604a) comprising computer-executable instructions that, when executed by processing circuitry (1402, 1502, 1604) of a second node (511, 530, 910, 920, 930, 1310, 1312, 1400, 1500, 1602) configured to facilitate sensing in a wireless network (520, 1304), configure the second node to perform operations corresponding to any of the methods of claims 23-36.

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