WO2025193136A1

WO2025193136A1 - Multi-static sensing

Info

Publication number: WO2025193136A1
Application number: PCT/SE2024/050686
Authority: WO
Inventors: Behrooz MAKKI; Georgios MYLONOPOULOS; Gabor Fodor; Stefano BUZZI
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2024-03-14
Filing date: 2024-07-15
Publication date: 2025-09-18
Anticipated expiration: 2026-09-14

Abstract

A method for multi-static sensing. The method includes configuring a multi-static sensing system to sense a non-cooperative object. The multi-static sensing system comprises a first node and a second node. Configuring the multi-static sensing system to sense the non-cooperative object comprises configuring the first node for transmitting a sensing signal and, based on the configuration of the first node, configuring the second node for receiving the sensing signal. The first node has at least two sub-arrays, and/or the second node has at least two sub-arrays.

Description

MULTI-STATIC SENSING

TECHNICAL FIELD

[0001] Disclosed are embodiments related to multi-static sensing.

BACKGROUND

[0002] Joint Communication and Sensing (JCS)

[0003] Radar technology for sensing and cellular technology for wireless telecommunication have coexisted for decades, and thanks to interference management efforts, the two technologies have coexisted without causing interference to one another. But this interference management has caused additional costs for infrastructure and inefficiencies in spectrum usage. With Fifth Generation (5G) and beyond, however, we have access to wide bandwidth and large antenna systems, which are the key requirements for sensing functionalities.

[0004] Also, key radar bands for high resolution sensing are merging with the millimeter wave (mmw) communication bands. For instance, some of the popular radar bands like K (18 GHz-26.5GHz) and Ka (26.5 GHz - 40 GHz) are close to popular mmw communication bands. Also, possible use of sub-THz bands (100-300 GHz) in Sixth Generation (6G) makes it possible to perform accurate sensing using different wireless access points, e.g., 5G base station (gNBs). These open up opportunities for the so-called joint communication and sensing (JCS) systems, which are also called integrated communication and sensing (ICS) systems. Currently in 3GPP, the term “integrated sensing and communication (ISAC)” is used. However, the terms “integrated sensing and communication (ISAC)”, “integrated communication and sensing (ICS)” and “Joint Communication and Sensing (JCS)” all mean the same thing.

[0005] With JCS, the objective is to share the spectrum more efficiently and/or reuse the existing cellular network infrastructure for sensing. In other words, the JCS refers to the introduction of sensing capability as part of a wireless communication networks. Here, sensing refers to “radar-like” functionalities, i.e., the ability to detect the presence, and to track the movement, and other characteristics of connected or unconnected objects under the coverage of the wireless network. Compared to the deployment of a separate network for sensing functionality, the main benefit of JCS is that the sensing capability can be introduced on large scale at a relatively low incremental cost by reusing the infrastructure that is deployed for communication purposes.

[0006] In general, as described in reference [1], sensing methods can be divided into two categories: Mono-static sensing and Multi-static sensing.

[0007] With mono-static sensing, the transmission of the sensing signal and the reception of the reflected signal are handled by the same node. In contrast, with multi-static sensing, the transmission and the reception can be handled by different collaborating nodes. The most common type of multi-static sensing is bi-static sensing where a first node transmits a sensing signal and a second node receives the reflections of the transmitted sensing signal.

[0008] Mono-static sensing typically requires full duplex capability at the sensing- capable node (e.g., base station). This is intuitively because in a typical sensing scenario the sensing range may be in the order of few to hundreds of meters and, thereby, the reflected wave may be received within a fraction of a microseconds which is shorter than in typical data communication systems with larger time scales (in the order of tens of microseconds). Full duplex, however, may be challenging as it requires high level of self-interference cancellation. With a multi-static sensing, on the other hand, full duplex is not required as the signal is transmitted and received by different nodes. On the other hand, multi-static sensing requires tight coordination and timing synchronization between the two or more nodes.

[0009] Large Antenna Systems

[00010] Multiple-input multiple-output (MIMO) is one of the key physical layer technologies in 5G. Here, a gNB with many, e.g., 64, antenna elements provide large array gains and/or performs spatial multiplexing of many users on the same time-frequency resources. Particularly, the received signal-to-noise ratio (SNR) increases with the number of antenna elements. Hence, the spectral efficiency can be increased or, equivalently, the required power to satisfy a quality-of-service requirement can be decreased as the number of antenna elements increases.

[00011] Due to the success of MIMO, it is expected that beyond 5G and 6G systems will make use of even larger antenna systems at the gNB. Particularly, currently very large arrays are deeply discussed as a possible study in 3GPP Rel-19, where different aspects such as channel modeling, CSI acquisition, and precoding enhancement, etc. may be included in 3GPP Rel-19. transmission and reception points (TRPs) operating at high bands may have multiple antenna panels where sometimes the panels will be pointing in different directions.

SUMMARY

[00012] Certain challenges presently exist. For instance, with a large number of antenna elements at the transmitter node and/or the receiver node of a multi-static sensing network, it is probable that different groups of antenna elements (a.k.a., sub-arrays) see different scattering clusters or different blocking objects, which results in significantly different channel responses observed by the different sub-arrays and, consequently, sensing quality. This cluster diversity probability increases considerably as the distance between the transmitters, receivers and the objects of interest for detection and tracking decreases and/or the carrier frequency increases.

[00013] Additionally, depending on the transmitting and/or receiving nodes capabilities, e.g., for full duplex communications and JCS operation, and/or the sensing accuracy and communication quality-of-service (QoS) requirements, it may be required to operate with only some of the sub-arrays at the transmitting/receiving nodes, since a disjoint sub-set may be strictly reserved for communication purposes, blocked, etc.

[00014] The problem in these situations consists of configuring the available antenna resources such that both the communication and sensing performances are satisfactory and the sensing (detection and parameter estimation) as well as communication QoS requirements are met, both when objects are far from or close to the transmitting/receiving nodes.

[00015] Accordingly, in one aspect there is provided a method for multi-static sensing. The method includes configuring a multi-static sensing system to sense a non-cooperative object. The multi-static sensing system comprises a first node and a second node. Configuring the multistatic sensing system to sense the non-cooperative object comprises configuring the first node for transmitting a sensing signal and, based on the configuration of the first node, configuring the second node for receiving the sensing signal. The first node has at least two sub-arrays, and/or the second node has at least two sub-arrays.

[00016] In another aspect there is provided a computer program comprising instructions which when executed by processing circuitry of an apparatus causes the apparatus to perform any of the methods disclosed herein. In one embodiment, there is provided a carrier containing the computer program wherein the carrier is one of an electronic signal, an optical signal, a radio signal, and a computer readable storage medium. In another aspect there is provided an apparatus that is configured to perform the methods disclosed herein. The apparatus may include memory and processing circuitry coupled to the memory.

[00017] An advantage of the embodiments disclosed herein is that they enable proper multi-static sensing of non-cooperative objects in the cases with a large number of antenna elements at the transmitting and/or the receiving nodes, depending on the node’s capabilities/sensing accuracy requirements and/or the channel conditions in different subarrays. This enables the network to analyze the coverage area in both short and long distances, which, in turn, helps the sensing and communication quality to meet minimum requirements. In this way, the proposed embodiments address one of the points of interest in Rel-19 as well as in 6G.

BRIEF DESCRIPTION OF THE DRAWINGS

[00018] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments.

[00019] FIG. 1 illustrates an example multi-static sensing scenario.

[00020] FIG. 2 illustrates an example multi-static sensing scenario.

[00021] FIG. 3 illustrates an example multi-static sensing scenario.

[00022] FIG. 4 illustrates an example multi-static sensing scenario.

[00023] FIG. 5 illustrates a multi-static sensing system according to an embodiment.

[00024] FIG. 6 is a flowchart illustrating a process according to an embodiment.

[00025] FIG. 7 is a flowchart illustrating a process according to an embodiment.

[00026] FIG. 8 is a flowchart illustrating a process according to an embodiment.

[00027] FIG. 9 is a flowchart illustrating a process according to an embodiment.

[00028] FIG. 10 is a block diagram of a network node according to an embodiment.

DETAILED DESCRIPTION [00029] As noted above, it is possible that different sub-arrays of a transmitting node and/or receiving node a may experience significantly different channel conditions, e.g., they may see different scattering clusters or different blocking objects. Such a probability and its effect increase considerably as the distance decreases and/or the carrier frequency /array sizes increases. It is noted that, as used herein, a “sub-array” is an arbitrary subset of antenna elements and/or panels of an antenna system.

[00030] FIGs. 1, 2, 3, and 4 illustrate various multi-static sensing use cases where a subarray in the transmitting/receiving nodes is blocked or useful for the sensing functionalities and different parts in the transmitting/receiving nodes have different sensing requirements.

[00031] FIG. 1 shows a scenario in which a transmitting node 101 that is used to sense a target 111 includes an antenna system having two sub-arrays: sub-array 102 (a.k.a., “TX subarray 1”) and sub-array 104 (a.k.a., “TX sub-array 2”). In the example shown, an obstacle 109 blocks TX sub-array 1. A portion of the transmitted energy is reflected by the target 111. One sensing node, node 121 (a.k.a., “Rx node 1”), which includes a first sub-array 131 and a second sub-array 132, receives the target’s echo, with a portion of the sensing node being blocked by an obstacle. Another node 122 used for sensing (a.k.a., “Rx node 2”) receives the transmitted energy directly but with a sub-array 123 of node 122’s antenna system 130 being shadowed by the target.

[00032] FIG. 2 shows a scenario where sub-array 131, such as a first panel, and sub-array 132, such as a second panel, may inspect an area with different geometrical characteristics, i.e., angle and range. Different inspection perspectives allow for target triangulation algorithms to be employed. Moreover, different regions are visible to different sub-arrays. As illustrated in FIG. 2, sub-array 131 may be positioned on a first side of a building 299 while sub-array 132 is on a second side of building 299.

[00033] FIG. 3 show a use-case scenario where i) a first target 301 is sensed using a first sensing signal 351 transmitted using a first transmitting (TX) sub-array 311 and using RX subarray 131 to receive signal 351 and ii) a second target 302 is sensed using a second sensing signal 352 transmitted using a second TX sub-array 312 and using RX sub-array 132 to receive signal 352. That is, in the example, shown, target 301 is visible to sub-array 131 and target 302 is visible to sub-array 132. As further shown in FIG. 3, sub-array 311 may be positioned on a first side of a building 390 while sub-array 312 is on a second side of building 390.

[00034] FIG. 4 shows a scenario where i) a first target 401 is sensed using a sensing signal 451 transmitted using TX array 411 and using RX sub-array 131 to receive signal 451 and ii) a second target 402 is sensed using a second sensing signal 452 transmitted using TX array 411 and using RX sub-array 132 to receive signal 452. That is, FIG. 4 illustrates that different targets can be visible to different sub-arrays of receiving sensing node 121. FIG. 4 further illustrates repeater-assisted sensing using a reflector. That is, in the example illustrated in FIG. 4, signal 451 is reflected by a reflector 420 prior to being reflected by target 401. The repeater/strong reflector may provide an inspection point visible to a portion of the receiving sensing node. Also, in this scenario, sub-array 131 and sub-array 132 are mounted on a vehicle 490. In the example shown in FIG. 4, TX array 411 benefits from the presence of a strong reflector, intelligent reflecting surface (IRS), network-controlled repeater (NCR), etc. to transmit sensing signals in different directions which are received by the receiving sub-arrays with different directions/properties and the sensing quality can be improved via, e.g., triangulation.

[00035] In the examples shown, the sub-arrays of TX node 101 and RX node 121 are nonoverlapping, however, in other embodiments, the sub-arrays of a node may be overlapping.

[00036] Depending on a node’s capabilities, e.g., for interference cancellation/full duplex operation/JCS operation, and/or the sensing quality requirement, it may be required and/or beneficial to operate only some of the node’s sub-arrays. Moreover, nodes operating at high bands may have multiple sub-arrays, such as, for example, multiple panels, and sometimes the sub-arrays will be pointing in different directions (see, e.g., FIG. 3). In these cases, different subarrays may provide different views on the target. Here, one example is vehicle-mounted arrays, where different panels point in different directions as shown in FIG. 4.

[00037] As illustrated by the above examples, there is a need for methods to i) determine whether different transmit/receive sub-arrays require different configurations for sensing, ii) configure them properly, and iii) adapt the sensing method accordingly. This is a motivation for this disclosure, which describes, among other things, methods for sub-array-based sensing of non-cooperative objects in a multi-static sensing environment. [00038] FIG. 5 illustrates a JCS, multi-static sensing system 500 according to an embodiment. System 500 includes TX node 101, RX node 121, and a controller 501, which may also be referred to as a “central unit.” TX node 101 may be a gNB, UE, fixed wireless access (FWA) node, integrated access and backhaul (IAB) node, etc. Likewise, RX node 121 may be a gNB, UE, FWA node, IAB node, etc. While controller 501 is shown as being separate and apart from nodes 101 and 121, in other scenarios controller 501 may be a component of node 101 and/or node 121.

[00039] System 500 is capable of sensing a target 591, which in this case is a non- cooperative object. In one embodiment, the sensing of target 591 is based on an adaptive subarray configuration. At a high-level, the adaptive sub-array configuration includes: 1) controller 501 configures the transmitting node 101 and/or the receiving node 121 with transmit and receive configurations, respectively, based on sub-array processing, 2) controller 501 configuring the receiving node 121 with an appropriate sensing method based on sub-array processing, and 3) controller 501 receiving a report about target 591 based on the determined configuration and the selected sensing method. Moreover, according to an embodiment, controller 501 may receive initial indications from the transmitting/receiving nodes 101 and 121 which helps the controller 501 to determine the need for sub-array -based sensing.

[00040] In short, this disclosure provides multi-static sensing non-cooperative objects that may be close or far from the transmitting and/or receiving node (measured in carrier wavelength) while a controller (which may be part of the at the transmitter(s), receiver(s) or other nodes) controls the available array resources for sensing and communications and uses sub-array processing. This is of interest in the cases with large arrays, which is the case of interest in 3 GPP Rel-19 as well as in 6G. In one embodiment, based on possible initial determinations of the need for sub-array -based processing, the controller configures the transmitting and/or the receiving nodes with proper transmitting and/or receiving configurations in their sub-arrays. Also, an appropriate sub-array-based sensing method is decided accordingly and the transmitting/receiving sub-arrays configurations to improve the sensing quality.

[00041] FIG. 6 is a flowchart illustrating a process according to an embodiment. In FIGs. 6-9 a dashed-line box indicates an optional step. In step 100 shown in FIG. 6, controller 501 configures the transmitting and/or the receiving nodes with transmit and receive configurations, respectively, based on sub-array processing, and configures the receiving node(s) with an appropriate sensing method based on sub-array processing.

[00042] In one embodiment, configuring the transmitting node(s) with the transmit configuration may include one or more of

(1) determining the proper beam configurations for transmission in a set of sub-arrays/panels;

(2) determining the proper time/frequency resource blocks with respect to each beam configuration for a set of sub-arrays/panels;

(3) determining the sensing parameters including, e.g., the duration, the bandwidth, the frequency, the periodicity of the sensing signal, the transmit power in a set of sub-arrays,. . .

(4) determining the proper polarization for a set of sub-arrays/panels;

(5) turning ON/OFF a set of sub-arrays/panels in the transmitting node(s);

(6) determining the near- or far-field based beam configuration for a set of sub-arrays/panels of the transmitting node(s),

(7) dedicating a set of sub-arrays/panels for communication purposes.

[00043] In one embodiment, configuring the receiving node(s) with the receive configuration may include one or more of

(1) determining the proper beam configurations for reception in a set of sub-arrays/panels;

(3) informing the receiving node(s) about the sensing parameters used by the selected set of sub-arrays including, e.g., the duration, the bandwidth, the periodicity of the sensing signal, the transmit power in a set of transmitting sub-arrays/panels,. . . ;

(4) determining the proper polarization for a set of receiving sub-arrays/panels;

(5) turning ON/OFF a set of receiving sub-arrays/panels in the receiving node(s) (to save energy);

(6) determining the near- or far-field based beam configuration for a set of sub-arrays/panels of the receiving node(s); (7) dedicating a set of sub-arrays/panels for communication purposes.

[00044] For the transmission and/or reception configurations, the time/frequency resource block association indicates which beam(s) to be used by which set of sub- arrays/panels in which time/frequency resource blocks. Also, the time resource may be indicated in terms of symbols, slots, sub-frames, frames, specific time period, etc., and the time resource may be indicated based on a combination of the beginning, ending, periodicity, duration, etc. of the desired period. In another embodiment, the ON/OFF configuration of the transmitting/receiving sub-arrays may be implicit or explicit where implicit OFF indication is via lack of beam/time configuration for the set of transmitting/receiving sub-arrays/panels (otherwise, a sub-array with a beam and/or time configuration is ON).

[00045] Note that, for both transmit and/or receive configurations, near-field or far-field based beam configuration follows the beam-focusing and beamforming method, respectively, in the set of sub-arrays/panels of the transmitting/receiving node(s). With beamforming, the beams cover different directions. With beam-focusing, on the other hand, each beam focuses the energy on a specific direction plus distance, i.e., it provides a focal point.

[00046] With transmit (respectively, receive) beam configuration, at least one sensing signal is sent (respectively, received) for one or more transmitting (respectively, receiving) beams of the selected set of sub-arrays/panels of the transmitting (respectively, receiving) node(s), e.g., one or more sensing signals is transmitted (respectively, received) in multiple different beams by the selected set of sub-arrays of the transmitting (respectively, receiving) node(s), where the beams can be narrow, semi-wide or wide, and they cover different directions and/or distances.

[00047] In one embodiment, controller 501 may inform the receiving node(s) about the determined sub-array -based configuration of the transmitting node(s).

[00048] In one embodiment, the configurations of the transmitting and/or receiving nodes may be periodic, semi -persistent or dynamic. In another embodiment, the signaling to the transmitting and/or receiving nodes about the proper configuration is based on downlink control information (DCI), MAC control element (MAC CE), Radio Resource Control (RRC), Xn interface, etc. [00049] In an optional step 80 of FIG. 6, prior to determining the transmit/receive configurations, controller 501 may receive a capability report about the transmitting and/or the receiving nodes. Here, the report about the transmitting and/or receiving node(s) may be received separately or jointly. In one embodiment, the capability report may be based on RRC or MAC-CE signaling.

[00050] In one embodiment, controller 501 may receive the capability report from: the transmitting and/or the receiving node(s), higher layers, 0AM, or another node.

[00051] In another embodiment, the capability report may include information about one or more of:

(1) the number of antennas/panels, polarizations, antennas/panels coordinates, etc. in the array and/or sub-arrays of the transmitting and/or the receiving nodes,

(2) the antenna constellations (X-by-Y) in the transmitting and/or the receiving node(s),

(3) the capability for sub-array -based processing in the transmitting and/or the receiving node(s),

(4) the ON/OFF capability of the transmitting and/or the receiving node(s) in the sub- arrays/panels,

(5) the power allocation capability of the transmitting node(s) in the array and/or sub-arrays,

(6) the pointing direction of the sub-arrays/panels of the transmitting and/or the receiving nodes,

(7) the beamforming capabilities (number of beams, beam types, etc.) in the arrays/panels and/or sub-arrays of the transmitting and/or receiving node(s),

(8) the near-filed and/or far-field based beamforming capabilities of the transmitting and/or receiving node(s),

(9) the transmitting and/or the receiving node’s full-duplex operation capability,

(10) the transmitting and/or the receiving node’s JCS operation capability,

(11) the transmitting and/or the receiving node’s capability for Tx/Rx switching in different subarrays,

(12) the downlink (DL) and/or uplink (UL) switching delay for sensing,

(13) the DL and/or UL switching time accuracy for sensing, [00052] The sensing may be based on single polarization, dual polarization, or alternating polarization.

[00053] In one embodiment, the configuration of the transmitting and/or receiving nodes may be based on: the sensing and/or the communication quality-of-service requirement; the transmitting and/or receiving node(s) capability reports received in step 80; controller 501 ’s prior knowledge about the area; and/or previous reports from the receiving node(s), e.g., about the object.

[00054] In one embodiment, the receive configuration of the receiving node(s) may be associated with the transmit configuration of the transmitting node(s). In another embodiment, adapting the transmit/receive configurations for different sub-arrays in the transmitting and receiving nodes may be based on the communication data traffic if the nodes operate in the JCS mode.

[00055] In an optional step 90 of FIG. 6, controller 501 may receive assistance information, implicit or explicit, that helps controller 501 to determine the need for sub-array- based sensing. Such an assistance information may include information about: the possible presence of obstacles blocking a set of transmitting and/or receiving sub-arrays, an estimate of LOS/NLOS links with respect to a set of sub-arrays, capability of the receiving node(s) to sense the object, and/or observing considerably different metrics in the sub-arrays. Different metrics to be measured in the sub-arrays may include: received power in different sub-arrays of the receiving node(s), angle-of-arrival in different sub-arrays of the receiving node(s), the Doppler-shift in different sub-arrays of the receiving node(s), timing measurement in different sub-arrays of receiving node(s), the number of received signals (echos) in different sub-arrays of the receiving node(s), the LOS/NLOS condition for different sub-arrays of the receiving node(s), and/or the polarization of the received signals (echos) for different sub-arrays of the receiving node(s).

[00056] After the transmit and receive configurations are determined, controller 501 triggers the transmission of at least one sensing signal via the selected set of transmitting subarrays. Then, using the receive configuration, the selected set of sub-arrays of the receiving node(s) receive reflections from the signals transmitted by the selected set of sub-arrays of the transmitting node(s) towards the object and the location of the object is sensed by processing at least one received signal in a set of sub-arrays of the receiving node(s). Here, the object can be sensed by additional knowledge of the beam direction of the transmitting and/or the receiving nodes’ beams used to transmit/receive the at least one sensing signal in different sub-arrays.

Also, the object may be sensed by evaluation of the received signal(s) in different sub-arrays of the receiving node(s).

[00057] In one embodiment, evaluation of the received signal in different sub- arrays/panels may be based on:

(1) measurements of the received power in different sub-arrays/panels of the receiving node(s)’ array/panels,

(2) measurements of the angle-of-arrival in different sub-arrays/panels of the receiving node(s),

(3) measurements of the Doppler-shift in different sub-arrays/panels of the receiving node(s),

(4) timing measurements in different sub-arrays/panels of the receiving node(s),

(5) an evaluation of the number of received signals (echos) in different sub-arrays/panels of the receiving node(s),

(6) the LOS/NLOS condition for different sub-arrays/panels, and/or

(7) the polarization of the received signals (echos) for different sub-arrays of the receiving node(s).

[00058] Evaluating and identifying different received signals among sub-arrays, in terms of, e.g., received power, angle-of-arrival, timing, etc., allows the identification of: (1) different links between the sensed target and the receive nodes, (2) different target(s) sensed by different sub-arrays (identifying distinctively different echos), (3) different target(s) obstructing a number of receive sub-arrays that a number of transmit sub-arrays is expected to illuminate, and/or subarrays that do not contribute due to obstructions.

[00059] Then, depending on the geometrical characteristics of the considered application and the information available, e.g., known repeater positions, known obstacles etc., the configurations and/or sensing method can be adapted. This may include turning ON/OFF a number of Tx sub-arrays and/or Rx sub-arrays, ignoring the signals received in some sub-arrays, allocating a number of Tx and/or Rx sub-arrays for communication purposes, using triangulations for sensing the object, proper configuration of the intermediate repeaters, etc.

[00060] Different state-of-the-art methods can be used to determine the LOS/NLOS condition for different sub-arrays. For instance, the estimated location of the object together with beam directions of the transmitting and/or receiving nodes in different sub-arrays may be used to estimate the probability that there is a LOS/NLOS path between the object and a sub- array/panel.

[00061] In one embodiment, the employed sensing method may be based on processing a subset of sub-arrays of the receiving node(s). For instance, a sub-array based sensing method may be based on triangulation of the signals received in different sub-arrays of the receiving node(s). In another embodiment, the sensing method may be based on the considered near-field (beam-focusing) or far-field (beamforming) based beam configurations of the transmitting and/or receiving sub-arrays. Also, the sub-array-based sensing method may exploit the information obtained from different combinations of the transmitting and receiving sub-arrays in the transmitting and receiving nodes, respectively.

[00062] In step 110 of FIG. 6, controller 501 receives a report about the sensed object based on the determined configuration and the selected sensing method. In one embodiment, the report may include information about: the position of the object, the velocity of the object, the selected sensing method, the receiving node(s) (in)ability to sense the object, LOS/NLOS probability of the object-receiving node links, an estimated accuracy of the sensing results, and/or the number of objects sensed. The report may also include a request for a new sub- array-based processing. In one embodiment, the report may include information per sub-array. In one embodiment, the report may be based on Xn interface or MAC-CE, DCI, RRC, signaling.

[00063] In this way, accurate multi-static sensing using sub-array processing is enabled. This, in turn, improves the network understanding of the area and improves the communication quality.

[00064] Depending on the considered sensing quality and/or the number of transmit/receive sub-arrays, the sensing signal parameters may be adapted. For example, the duration, bandwidth, periodicity of the sensing signal, and/or Tx power are among the parameters that may be adapted. For a specific sensing time resource, the signal can be adjusted for sensing. For instance, based on the considered sensing quality, the sensing signal parameters can be selected. As an example, the duration, bandwidth, frequency, and periodicity of the sensing signal can be selected based on Table 1 below. Table 1. Determining the sensing signal parameters.

[00065] FIG. 7 is a flowchart illustrating a process performed by a receiving node. The process may begin with optional steps 180 and 190. In step 180, the receiving node transmits a capability report to controller 501 (a.k.a., “central unit”). In step 190, the receiving node transmits to controller 501 the assistance information described above to assist controller 501 in determining whether sub-array based sending is needed. In step 200, the receiving node receives i) receiver configuration information indicating a sub-array configuration and ii) information indicating a sensing method. In step 210, the receiving node receives reflections of at least one sensing signal and performs the indicated sensing method. In step 220, the receiving node transmits a report containing the information described above with respect to step 110.

[00066] FIG. 8 is a flowchart illustrating a process performed by a transmitting node. The process may begin with optional step 290. In step 290, the transmitting node transmits a capability report to controller 501. In step 300, the transmitting node receives transmitter configuration information indicating a sub-array configuration for the transmitting node. In step 310, the transmitting node transmits at least one sensing signal based on the received transmitter configuration.

[00067] FIG. 9 is a flow chart illustrating a process 900, according to an embodiment, for multi-static sensing. Process 900 may begin in step s902. Step s902 comprises configuring a multi-static sensing system (e.g., system 500) to sense a non-cooperative object. The multi-static sensing system comprises a first node and a second node. Configuring the multi-static sensing system to sense the non-cooperative object comprises configuring the first node for transmitting a sensing signal and, based on the configuration of the first node, configuring the second node for receiving the sensing signal. The first node has at least two sub-arrays, and/or the second node has at least two sub -arrays.

[00068] In some embodiments, the method further comprises: prior to configuring the multi-static sensing system to sense the non-cooperative object, determining whether there is a need to perform the configuration based on transmit and/or receive sub-arrays properties.

[00069] In some embodiments, the method further comprises obtaining decision information, determining whether there is a need to perform the configuration comprises using the decision information to determine whether there is a need to perform the configuration, and the decision information comprises one or more of information indicating the presence of an obstacle blocking a sub-array of the first node and/or blocking a sub-array of the second node, information indicating an estimate of line-of-sight, LOS, links with respect to the sub-array of the first node and/or the sub-array of the second node, information indicating that the second node is not capable of sensing the non-cooperative object, received power information indicating a received power of a signal received using a first sub-array of the second node and a received power of the signal received using a second sub-array of the second node, angle-of-arrival (AoA) information indicating an AoA a signal received using the first sub-array of the second node and an AoA of the signal received using the second sub-array of the second node, doppler shift information indicating a first doppler shift associated with the first sub-array of the second node and a second doppler shift associated with the second sub-array of the second node, timing measurement information indicating a first timing measurement associated with the first subarray of the second node and a second timing measurement associated with the second sub-array of the second node, echo signal information indicating a first number of echo signals associated with the first sub-array of the second node and a second number of echo signals associated with the second sub-array of the second node, LOS information indicating a first LOS condition associated with the first sub-array of the second node and a second LOS condition associated with the second sub-array of the second node, or echo signal polarization information indicating a first polarization of a first echo signal received using first sub-array of the second node and a second polarization of a second echo signal received using second sub-array of the second node.

[00070] In some embodiments, the first node has a first sub-array and a second sub-array, and configuring the first node comprises: configuring the first node to use the first sub-array to transmit a first beam having a first beam width; and configuring the first node to use the second sub-array to transmit a second beam having a second beam width that is narrower than the first beam width.

[00071] In some embodiments, the first node has a first sub-array and a second sub-array, and configuring the first node comprises: configuring the first node to use the first sub-array to transmit a first beam in a first direction, and configuring the first node to use the second subarray to transmit a second beam in a second direction.

[00072] In some embodiments, the first node has a first sub-array and a second sub-array, and configuring the first node comprises: configuring the first node to use the first sub-array to transmit a sensing signal for use in sensing the non-cooperative object, and configuring the first node to use the second sub-array for transmitting communication signals, or configuring the first node to use the first sub-array to transmit a sensing signal for use in sensing the non-cooperative object, and configuring the first node to turn-off the second sub-array.

[00073] In some embodiments, the second node has a first sub-array and a second subarray, and configuring the second node comprises: configuring the second node to use the first sub-array and a first receive beam for receiving signals; and configuring the second node to use the second sub-array and a second receive beam for receiving signals, wherein the second receive beam is narrower than the first receive beam.

[00074] In some embodiments, the second node has a first sub-array and a second subarray, and configuring the second node comprises: configuring the second node to use the first sub-array and a first receive beam pointing in a first direction for receiving signals; and configuring the second node to use the second sub-array and a second receive beam pointing in a second direction for receiving signals, wherein the second direction is different than the first direction.

[00075] In some embodiments, the second node has a first sub-array and a second subarray, and configuring the second node comprises: configuring the second node to use the first sub-array to receive a sensing signal for use in sensing the non-cooperative object, and configuring the second node to use the second sub-array for receiving communication signals or to turn-off the second sub-array.

[00076] In some embodiments, configuring the second node further comprises informing the second node about sensing parameters of sensing signal transmitted by the first node.

[00077] In some embodiments, the sensing parameters include one or more of: a duration of the sensing signal, a bandwidth of the sensing signal, a periodicity of the sensing signal, or a transmit power.

[00078] In some embodiments, the method further comprises, prior to configuring the first node, receiving a first capability report pertaining to the first node, and the first capability report comprises first capability information indicating one or more of: a number of antenna arrays that the first node can use for sensing the non-cooperative object, an antenna constellation in the first node, a capability for sub-array processing, a power allocation capability, for one or more subarrays of the first node, a pointing direction of the sub-array, a beamforming capability, a full- duplex operation capability, a joint communication and sensing, JCS, capability, a switching delay capability, a position of a sub-array of the first node, or a switching time accuracy.

[00079] In some embodiments, the method further comprises, prior to configuring the second node, receiving a second capability report pertaining to the second node, and the second capability report comprises second capability information indicating one or more of: a number of antenna arrays that the second node can use for sensing the non-cooperative object, an antenna constellation in the second node, a capability for sub-array processing, a power allocation capability, for one or more sub-arrays of the second node, a pointing direction of the sub-array, a beamforming capability, a full-duplex operation capability, a joint communication and sensing, JCS, capability, a switching delay capability, a position of a sub-array of the second node, or a switching time accuracy. [00080] In some embodiments, the method further comprises: selecting a sensing method; and instructing the second node to use the selected sensing method to sense the non-cooperative object.

[00081] In some embodiments, the selected sensing method is a sensing method based one or more of: time of arrival measurements, received power measurements, phase measurements, doppler shift measurements, triangulation of received reflections of the sensing signal, or beam configurations of the first node and/or second node.

[00082] In some embodiments, the method further comprises triggering the first node to transmit the sensing signal, and the second node receives a reflection of the sensing signal.

[00083] In some embodiments, the second node estimates a location of the non- cooperative object by performing one or more of: measuring received power of the reflection of the sensing signal, measuring an angle-of-arrival, AoA, of the reflection of the sensing signal, measuring a doppler shift of the reflection of the sensing signal, determining a timing difference between the time the reflection of the sensing signal is received at a first sub-array of the second node and the time the reflection of the sensing signal is received at a second sub-array of the second node, determining a number of reflected signals received, or determining a polarization of the reflected signal.

[00084] In some embodiments, the method further comprises determining a probability that there is a line-of-sight, LOS, path between the non-cooperative object and a sub-array of the first node or second node.

[00085] In some embodiments, the probability is based on the estimate of the location of the object and a direction of beam that was used to transmit or receive the sensing signal.

[00086] In some embodiments, the method further comprises receiving a report, and the report includes information about one or more of: a position of a sensed object a velocity of the sensed object, an indication of the selected sensing method, a LOS probability, an estimated accuracy of the sensing results, or the number of sensed objects.

[00087] In some embodiments, the method is performed by the first node, the method is performed by the second node, the method is performed by a controller separate from the first node and the second node, the first node is a first base station, and/or the second node is a user equipment or a second base station.

[00088] FIG. 10 is a block diagram of network node 1000, according to some embodiments, which can implement TX node 101, RX node 121, and/or controller 501. As shown in FIG. 10, network node 1000 may comprise: processing circuitry (PC) 1002, which comprises one or more processors (P) 1055 (e.g., one or more general purpose microprocessors and/or one or more other processors, such as an application specific integrated circuit (ASIC), field-programmable gate arrays (FPGAs), and the like), which processors may be co-located in a single housing or in a single data center or may be geographically distributed (e.g., network node 1000 may be a distributed computing apparatus comprising two or more computers or a monolithic computing apparatus consisting of a single computer); at least one network interface 1048 (e.g., a physical interface or air interface) comprising a transmitter (Tx) 1045 and a receiver (Rx) 1047 for enabling network node 1000 to transmit data to and receive data from other nodes connected to network 110 (e.g., an Internet Protocol (IP) network) to which network interface 1048 is connected (physically or wirelessly) (e.g., network interface 1048 may be coupled to an antenna arrangement comprising one or more antennas for enabling network node 1000 to wirelessly transmit/receive data); and a storage unit (a.k.a., “data storage system”) 1008, which may include one or more non-volatile storage devices and/or one or more volatile storage devices. In embodiments where PC 1002 includes a programmable processor, a computer readable storage medium (CRSM) 1042 may be provided. CRSM 1042 may store a computer program (CP) 1043 comprising computer readable instructions (CRI) 1044. CRSM 1042 may be a non-transitory computer readable medium, such as, magnetic media (e.g., a hard disk), optical media, memory devices (e.g., random access memory, flash memory), and the like. In some embodiments, the CRI 1044 of computer program 1043 is configured such that when executed by PC 1002, the CRI causes network node 1000 to perform steps described herein (e.g., steps described herein with reference to the flow charts). In other embodiments, network node 1000 may be configured to perform steps described herein without the need for code. That is, for example, PC 1002 may consist merely of one or more ASICs. Hence, the features of the embodiments described herein may be implemented in hardware and/or software.

[00089] While various embodiments are described herein, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of this disclosure should not be limited by any of the above-described exemplary embodiments. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

[00090] As used herein transmitting a message “to” or “toward” an intended recipient encompasses transmitting the message directly to the intended recipient or transmitting the message indirectly to the intended recipient (i.e., one or more other nodes are used to relay the message from the source node to the intended recipient). Likewise, as used herein receiving a message “from” a sender encompasses receiving the message directly from the sender or indirectly from the sender (i.e., one or more nodes are used to relay the message from the sender to the receiving node). Further, as used herein “a” means “at least one” or “one or more.”

[00091] Additionally, while the processes described above and illustrated in the drawings are shown as a sequence of steps, this was done solely for the sake of illustration. Accordingly, it is contemplated that some steps may be added, some steps may be omitted, the order of the steps may be re-arranged, and some steps may be performed in parallel.

[00092] References

[00093] [1] Behravan, A., et. al., "Introducing sensing into future wireless communication systems," 2nd IEEE International Symposium on Joint Communications & Sensing (JC&S), Seefeld, Austria, 1322, pp. 1-5.

Claims

1. A method (900) for multi-static sensing, the method comprising: configuring a multi-static sensing system (500) to sense a non-cooperative object (101, 301, 302, 401, 402, 591), wherein the multi-static sensing system comprises a first node (101) and a second node (121), and configuring the multi-static sensing system to sense the non-cooperative object comprises: configuring the first node for transmitting a sensing signal (351, 352, 451, 452); and based on the configuration of the first node, configuring the second node for receiving the sensing signal, wherein the first node has at least two sub-arrays (102, 104), and/or the second node has at least two sub-arrays (131, 132).

2. The method of claim 1, wherein the method further comprises: prior to configuring the multi-static sensing system to sense the non-cooperative object, determining whether there is a need to perform the configuration based on transmit and/or receive sub-arrays properties.

3. The method of claim 2, wherein the method further comprises obtaining decision information, determining whether there is a need to perform the configuration comprises using the decision information to determine whether there is a need to perform the configuration, and the decision information comprises one or more of: information indicating the presence of an obstacle blocking a sub-array of the first node and/or blocking a sub-array of the second node, information indicating an estimate of line-of-sight, LOS, links with respect to the subarray of the first node and/or the sub-array of the second node, information indicating that the second node is not capable of sensing the non- cooperative obj ect, received power information indicating a received power of a signal received using a first sub-array of the second node and a received power of the signal received using a second sub-array of the second node, angle-of-arrival (AoA) information indicating an AoA a signal received using the first sub-array of the second node and an AoA of the signal received using the second sub-array of the second node, doppler shift information indicating a first doppler shift associated with the first subarray of the second node and a second doppler shift associated with the second sub-array of the second node, timing measurement information indicating a first timing measurement associated with the first sub -array of the second node and a second timing measurement associated with the second sub-array of the second node, echo signal information indicating a first number of echo signals associated with the first sub-array of the second node and a second number of echo signals associated with the second sub-array of the second node,

LOS information indicating a first LOS condition associated with the first sub-array of the second node and a second LOS condition associated with the second subarray of the second node, or echo signal polarization information indicating a first polarization of a first echo signal received using first sub-array of the second node and a second polarization of a second echo signal received using second sub-array of the second node.

4. The method of any one of claims 1-3, wherein the first node has a first sub-array and a second sub-array, and configuring the first node comprises: configuring the first node to use the first sub-array to transmit a first beam having a first beam width; and configuring the first node to use the second sub-array to transmit a second beam having a second beam width that is narrower than the first beam width.

5. The method of any one of claims 1-3, wherein the first node has a first sub-array and a second sub-array, and configuring the first node comprises: configuring the first node to use the first sub-array to transmit a first beam in a first direction, and configuring the first node to use the second sub-array to transmit a second beam in a second direction.

6. The method of any one of claims 1-3, wherein the first node has a first sub-array and a second sub-array, and configuring the first node comprises: configuring the first node to use the first sub -array to transmit a sensing signal for use in sensing the non-cooperative object, and configuring the first node to use the second sub-array for transmitting communication signals, or configuring the first node to use the first sub -array to transmit a sensing signal for use in sensing the non-cooperative object, and configuring the first node to turn-off the second sub-array.

7. The method of any one of claims 1-6, wherein the second node has a first sub-array and a second sub-array, and configuring the second node comprises: configuring the second node to use the first sub -array and a first receive beam for receiving signals; and configuring the second node to use the second sub-array and a second receive beam for receiving signals, wherein the second receive beam is narrower than the first receive beam.

8. The method of any one of claims 1-6, wherein the second node has a first sub-array and a second sub-array, and configuring the second node comprises: configuring the second node to use the first sub -array and a first receive beam pointing in a first direction for receiving signals; and configuring the second node to use the second sub-array and a second receive beam pointing in a second direction for receiving signals, wherein the second direction is different than the first direction.

9. The method of any one of claims 1-6, wherein the second node has a first sub-array and a second sub-array, and configuring the second node comprises: configuring the second node to use the first sub -array to receive a sensing signal for use in sensing the non-cooperative object, and configuring the second node to use the second sub-array for receiving communication signals or to turn-off the second sub-array.

10. The method of any one of claims 7-9, wherein configuring the second node further comprises informing the second node about sensing parameters of sensing signal transmitted by the first node.

11. The method of claim 10, wherein the sensing parameters include one or more of a duration of the sensing signal, a bandwidth of the sensing signal, a periodicity of the sensing signal, or a transmit power.

12. The method of any one of claims 1-11, wherein the method further comprises, prior to configuring the first node, receiving a first capability report pertaining to the first node, and the first capability report comprises first capability information indicating one or more of a number of antenna arrays that the first node can use for sensing the non-cooperative object, an antenna constellation in the first node, a capability for sub-array processing, a power allocation capability, for one or more sub-arrays of the first node, a pointing direction of the sub-array, a beamforming capability, a full-duplex operation capability, a joint communication and sensing, JCS, capability, a switching delay capability, a position of a sub-array of the first node, or a switching time accuracy.

13. The method of any one of claims 1-12, wherein the method further comprises, prior to configuring the second node, receiving a second capability report pertaining to the second node, and the second capability report comprises second capability information indicating one or more of: a number of antenna arrays that the second node can use for sensing the non- cooperative obj ect, an antenna constellation in the second node, a capability for sub-array processing, a power allocation capability, for one or more sub-arrays of the second node, a pointing direction of the sub-array, a beamforming capability, a full-duplex operation capability, a joint communication and sensing, JCS, capability, a switching delay capability, a position of a sub-array of the second node, or a switching time accuracy.

14. The method of any one of claims 1-13, wherein the method further comprises: selecting a sensing method; and instructing the second node to use the selected sensing method to sense the non- cooperative obj ect.

15. The method of claim 14, wherein the selected sensing method is a sensing method based one or more of: time of arrival measurements, received power measurements, phase measurements, doppler shift measurements, triangulation of received reflections of the sensing signal, or beam configurations of the first node and/or second node.

16. The method of any one of claims 1-15, wherein the method further comprises triggering the first node to transmit the sensing signal, and the second node receives a reflection of the sensing signal.

17. The method of claim 16, wherein the second node estimates a location of the non- cooperative object by performing one or more of: measuring received power of the reflection of the sensing signal, measuring an angle-of-arrival, AoA, of the reflection of the sensing signal, measuring a doppler shift of the reflection of the sensing signal, determining a timing difference between the time the reflection of the sensing signal is received at a first sub-array of the second node and the time the reflection of the sensing signal is received at a second sub-array of the second node, determining a number of reflected signals received, or determining a polarization of the reflected signal.

18. The method of claim 17, wherein the method further comprises determining a probability that there is a line-of-sight, LOS, path between the non-cooperative object and a subarray of the first node or second node.

19. The method of claim 18, wherein the probability is based on the estimate of the location of the object and a direction of beam that was used to transmit or receive the sensing signal.

20. The method of any one of claims 1-19, wherein the method further comprises receiving a report, and the report includes information about one or more of a position of a sensed object a velocity of the sensed object, an indication of the selected sensing method, a LOS probability, an estimated accuracy of the sensing results, or the number of sensed objects.

21. The method of any one of claims 1-20, wherein the method is performed by the first node, the method is performed by the second node, the method is performed by a controller separate from the first node and the second node, the first node is a first base station, and/or the second node is a user equipment or a second base station.

22. A computer program (1043) comprising instructions (1044) which when executed by processing circuitry (1002) of a node causes the node to perform the method of any one of claims 1-21.

23. A carrier containing the computer program of claim 22, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, and a computer readable storage medium (1042).

24. A controller (501), the controller being configured to perform a method comprising: configuring a multi-static sensing system (500) to sense a non-cooperative object (101, 301, 302, 401, 402, 591), wherein the multi-static sensing system comprises a first node (101) and a second node (121), and configuring the multi-static sensing system to sense the non-cooperative object comprises: configuring the first node for transmitting a sensing signal (351, 352, 451, 452); and based on the configuration of the first node, configuring the second node for receiving the sensing signal, wherein the first node has at least two sub-arrays (102, 104), and/or the second node has at least two sub-arrays (131, 132).

25. The controller of claim 24, wherein the method further comprises: prior to configuring the multi-static sensing system to sense the non-cooperative object, determining whether there is a need to perform the configuration based on transmit and/or receive sub-arrays properties.

26. The controller of claim 25, wherein the method further comprises obtaining decision information, determining whether there is a need to perform the configuration comprises using the decision information to determine whether there is a need to perform the configuration, and the decision information comprises one or more of: information indicating the presence of an obstacle blocking a sub-array of the first node and/or blocking a sub-array of the second node, information indicating an estimate of line-of-sight, LOS, links with respect to the subarray of the first node and/or the sub-array of the second node, information indicating that the second node is not capable of sensing the non- cooperative obj ect, received power information indicating a received power of a signal received using a first sub-array of the second node and a received power of the signal received using a second sub-array of the second node, angle-of-arrival (AoA) information indicating an AoA a signal received using the first sub-array of the second node and an AoA of the signal received using the second sub-array of the second node, doppler shift information indicating a first doppler shift associated with the first subarray of the second node and a second doppler shift associated with the second sub-array of the second node, timing measurement information indicating a first timing measurement associated with the first sub -array of the second node and a second timing measurement associated with the second sub-array of the second node, echo signal information indicating a first number of echo signals associated with the first sub-array of the second node and a second number of echo signals associated with the second sub-array of the second node,

27. The controller of any one of claims 24-26, wherein the first node has a first sub-array and a second sub-array, and configuring the first node comprises: configuring the first node to use the first sub-array to transmit a first beam having a first beam width; and configuring the first node to use the second sub-array to transmit a second beam having a second beam width that is narrower than the first beam width.

28. The controller of any one of claims 24-26, wherein the first node has a first sub-array and a second sub-array, and configuring the first node comprises: configuring the first node to use the first sub-array to transmit a first beam in a first direction, and configuring the first node to use the second sub-array to transmit a second beam in a second direction.

29. The controller of any one of claims 24-26, wherein the first node has a first sub-array and a second sub-array, and configuring the first node comprises: configuring the first node to use the first sub-array to transmit a sensing signal for use in sensing the non-cooperative object, and configuring the first node to use the second sub-array for transmitting communication signals, or configuring the first node to use the first sub-array to transmit a sensing signal for use in sensing the non-cooperative object, and configuring the first node to turn-off the second sub-array.

30. The controller of any one of claims 24-29, wherein the second node has a first sub-array and a second sub-array, and configuring the second node comprises: configuring the second node to use the first sub-array and a first receive beam for receiving signals; and configuring the second node to use the second sub-array and a second receive beam for receiving signals, wherein the second receive beam is narrower than the first receive beam.

31. The controller of any one of claims 24-29, wherein the second node has a first sub-array and a second sub-array, and configuring the second node comprises: configuring the second node to use the first sub-array and a first receive beam pointing in a first direction for receiving signals; and configuring the second node to use the second sub-array and a second receive beam pointing in a second direction for receiving signals, wherein the second direction is different than the first direction.

32. The controller of any one of claims 24-29, wherein the second node has a first sub-array and a second sub-array, and configuring the second node comprises: configuring the second node to use the first sub-array to receive a sensing signal for use in sensing the non-cooperative object, and configuring the second node to use the second sub-array for receiving communication signals or to turn-off the second sub-array.

33. The controller of any one of claims 30-32, wherein configuring the second node further comprises informing the second node about sensing parameters of sensing signal transmitted by the first node.

34. The controller of claim 33, wherein the sensing parameters include one or more of a duration of the sensing signal, a bandwidth of the sensing signal, a periodicity of the sensing signal, or a transmit power.

35. The controller of any one of claims 24-34, wherein the method further comprises, prior to configuring the first node, receiving a first capability report pertaining to the first node, and the first capability report comprises first capability information indicating one or more of a number of antenna arrays that the first node can use for sensing the non-cooperative object, an antenna constellation in the first node, a capability for sub-array processing, a power allocation capability, for one or more sub-arrays of the first node, a pointing direction of the sub-array, a beamforming capability, a full-duplex operation capability, a joint communication and sensing, JCS, capability, a switching delay capability, a position of a sub-array of the first node, or a switching time accuracy.

36. The controller of any one of claims 24-35, wherein the method further comprises, prior to configuring the second node, receiving a second capability report pertaining to the second node, and the second capability report comprises second capability information indicating one or more of: a number of antenna arrays that the second node can use for sensing the non- cooperative obj ect, an antenna constellation in the second node, a capability for sub-array processing, a power allocation capability, for one or more sub-arrays of the second node, a pointing direction of the sub-array, a beamforming capability, a full-duplex operation capability, a joint communication and sensing, JCS, capability, a switching delay capability, a position of a sub-array of the second node, or a switching time accuracy.

37. The controller of any one of claims 24-36, wherein the method further comprises: selecting a sensing method; and instructing the second node to use the selected sensing method to sense the non- cooperative obj ect.

38. The controller of claim 37, wherein the selected sensing method is a sensing method based one or more of: time of arrival measurements, received power measurements, phase measurements, doppler shift measurements, triangulation of received reflections of the sensing signal, or beam configurations of the first node and/or second node.

39. The controller of any one of claims 24-38, wherein the method further comprises triggering the first node to transmit the sensing signal, the second node receives a reflection of the sensing signal, and the second node estimates a location of the non-cooperative object by performing one or more of: measuring received power of the reflection of the sensing signal, measuring an angle-of-arrival, AoA, of the reflection of the sensing signal, measuring a doppler shift of the reflection of the sensing signal, determining a timing difference between the time the reflection of the sensing signal is received at a first sub-array of the second node and the time the reflection of the sensing signal is received at a second sub-array of the second node, determining a number of reflected signals received, or determining a polarization of the reflected signal.