Channel state information forwarding in passive wireless sensing networks

Abstract

The invention relates to performing sensing in a wireless network based on detecting changes in received radio frequency signals, and in particular to performing such sensing based on analysing channel state information. The wireless network comprises at least one node of a first type and a plurality of nodes of a second type, the at least one node of the first type being arranged for performing analysis of channel state information relating to wireless signals transmitted in the wireless network. One or more wireless signals are transmitted between the plurality of nodes of the second type, and at least one of the nodes determines channel state information relating to the one or more wireless signals and transmits at least a portion of the determined channel state information to a node of the at least one node of the first type. The node of the first type receives at least a portion of the determined channel state information and analyses it to determine a sensing value.

Description

Technical Field

[0001] The present invention relates to a method, apparatus, and system for performing passive wireless sensing in a wireless network based on detecting changes in received radio frequency signals, and more particularly to performing such sensing based on analyzing channel state information. Background Technology

[0002] Wireless networks, such as Wi-Fi networks, consist of several nodes that communicate with each other using radio frequency (RF) signals. These RF signals exchanged between nodes can be affected by absorption, reflection, and scattering from objects such as walls, doors, and human or animal bodies (when present). In recent years, Wi-Fi devices have begun to use Channel State Information (CSI), which indicates how a wireless signal propagates along multiple spatial paths at a specific carrier frequency in the wireless channel between the transmitter and receiver. Therefore, CSI captures the wireless characteristics of the surrounding environment because its amplitude and phase are affected by multipath effects, including amplitude attenuation and phase shift of the radio signal.

[0003] Time series of multiple CSI measurements capture how wireless signals propagate through space in the time, frequency, and spatial domains; therefore, the signals can be analyzed to enable a wide range of different wireless sensing applications. For example, the CSI amplitude variations in the time domain exhibit different patterns for different people, activities, postures, etc., which can be used for presence detection, motion detection, activity recognition, and more.

[0004] Analyzing RF signals can require powerful hardware, in terms of computing power and / or memory. This is especially true when performing analysis based on CSI, such as when the link has many subcarrier frequencies. Indeed, for modern Wi-Fi networks with multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM), CSI measurements provide a three-dimensional complex-valued matrix representing the changes in amplitude attenuation and phase shift over time.

[0005] Because multiple nodes are required, increasing the number of nodes in such a wireless network to improve coverage of the monitored area and allow for improved sensing can make such a system very expensive. Summary of the Invention

[0006] In a first aspect, a method for performing sensing in a wireless network is provided. The wireless network includes at least one node of a first type and a plurality of nodes of a second type. At least one node of the first type is arranged to perform analysis of channel state information (CSI) related to wireless signals transmitted in the wireless network. Therefore, this node requires specific hardware (e.g., a certain amount of memory and / or a certain amount of computing power) to allow it to perform this analysis. The second type of node differs from the first type of node. The second type of node does not need to be able to perform CSI analysis, although this does not preclude such nodes from having robust hardware requirements, such as for performing other functions.

[0007] The method includes transmitting one or more wireless signals among a plurality of second-type nodes. These signals may be transmitted solely for the purpose of performing analysis; however, they may also include data transmissions between nodes performed for other purposes. At least one of the plurality of second-type nodes determines a CSI associated with the one or more wireless signals. The at least one of the plurality of second-type nodes then transmits at least a portion of the determined CSI to a node of at least one first-type node. The at least one first-type node then receives at least a portion of the determined CSI and analyzes the received CSI. Based on the analysis, a sensed value is determined.

[0008] The second type of node is therefore able to determine (or, in other words, extract) and transmit (or, in other words, forward) at least a portion of the CSI, and at least one first type of node is able to process at least a portion of the received CSI. This allows the use of CSI associated with signals transmitted between multiple second type nodes during sensing, without requiring these second type of nodes themselves to perform the analysis. As a result, second type of nodes can be used to improve the coverage and / or quality of sensing performed in a wireless network, while reducing hardware requirements compared to utilizing only first type nodes, which may be more expensive. In other words, the system may include a first type node A located in area A and two second type nodes B1 and B2 located in area B, where areas A and B do not overlap. Prior art shows that node A can determine the CSI of a first signal transmitted from node B1 to node A, and further optionally determine the CSI of a second signal transmitted from node B2 to node A. Node A can analyze the CSI associated with the first signal and optionally the second signal to determine a sensed value (e.g., presence). Therefore, the sensed value is determined based on the CSI associated with the signals transmitted between (multiple) nodes in region B and nodes in region A; thus, sensing is performed on a combination of at least a portion of region A and at least a portion of region B. In this example, if presence sensing is performed, it can be detected when a person moves in region B (assuming the first or second signal is affected by the person moving in region B); however, if a person moves in region A, this detection will also be triggered (again, assuming the first or second signal is affected by the person moving in region A). Furthermore, the coverage of region B may not be optimal.

[0009] Continuing this example, as an alternative or supplement to the transmission of the first signal and optional second signal as described above, the present invention provides that one or more third signals are transmitted between nodes in region B (e.g., from B1 to B2), and in this example, the CSI of these one or more third signals is determined by B2 based on the signals it has already received from B1. The determined CSI (or a portion thereof) associated with these one or more third signals is then sent from the node that determined it (node ​​B2 in this example) to node A. Node A can then process (a portion thereof) of the CSI it has received. This CSI is now only associated with the signals(s) transmitted in region B between nodes in region B. In this example, the CSI analyzed by node A is associated with the signals transmitted from node B1 to node B2. Therefore, presence can be detected in region B instead of a combination of regions A and B, and the coverage of sensing in region B can be further improved.

[0010] The second type of node can be deployed to compress data (e.g., CSI) to occupy a smaller payload during transmission, for filtering or removing noise on multiple previously determined CSIs and / or extracting specific secondary features on multiple previously determined CSIs. For example, secondary features may indicate maximum / minimum amplitude / deviation / phase shift; if these maximum / minimum values ​​are not significantly different from previous values ​​received by the second type of node, the node can simply avoid processing the CSI and use its computational resources for other purposes. The level and / or type of preprocessing performed at the second type of node can be determined based on its computational power, its battery power level, power consumption, its memory usage, any other functions it is performing, etc., and based on the computational power of at least one first type of node. Furthermore, the type of sensing being performed (e.g., requiring maximum detection latency), the state of the wireless network, etc., can determine the extent of preprocessing performed.

[0011] In one embodiment, the method further includes transmitting one or more additional wireless signals between the node in at least one first-type node and one or more nodes in a plurality of second-type nodes. The node in at least one first-type node determines additional CSIs associated with the additional one or more wireless signals and analyzes the CSIs. The step of determining a sensed value is also based on the analysis of the additional CSIs.

[0012] This allows sensing to be performed based on both CSI extracted in relation to wireless signals transmitted between multiple second-type nodes and wireless signals transmitted between at least one first-type node and one or more second-type nodes, thereby further improving the quality coverage of the performed sensing. The sensed value may relate to a single characteristic, such as detecting the presence of a person; it may also relate to multiple characteristics, such as detecting the presence of a person and detecting the presence of an animal. Each such characteristic can be determined based on CSI related to signals transmitted between multiple second-type nodes, wireless signals transmitted between at least one first-type node and one or more second-type nodes, or both. For example, based on CSI related to wireless signals transmitted between at least one first-type node and one or more second-type nodes, the status of a residence can be determined as occupied or unoccupied, while CSI related to signals transmitted between multiple second-type nodes is used to determine the status of a single room (or multiple rooms, together or individually) as occupied or unoccupied.

[0013] In this embodiment, optionally, one or more additional wireless signals include the transmission of at least a portion of the determined CSI. Therefore, at least one node of the first type receives at least a portion of the CSI and further determines additional CSIs based on the transmission of that at least portion of the CSI. This allows the same message carrying at least a portion of the determined CSI to be used to determine additional CSIs, thereby making more efficient use of the wireless network and / or other resources.

[0014] In another embodiment, the sensed value indicates movement of an object within a sensed area defined by the positions of at least a plurality of nodes of a second type. For example, the plurality of second-type nodes may be located in rooms of a building (e.g., a residence). The sensed area can then be defined as that room (or a portion thereof). This facilitates movement detection (including presence detection) and thus allows the detection of the movement or presence of a person, animal (e.g., a pet), or another object.

[0015] In another embodiment, determining the CSI associated with one or more wireless signals by at least one of a plurality of second-type nodes includes extracting a plurality of time-series values ​​from the communication stack of at least one of the plurality of second-type nodes. Determining the CSI associated with one or more wireless signals by at least one of the plurality of second-type nodes may further include, for example, selecting the frequency or period from which the CSI is extracted, or what CSI is extracted (e.g., which sub-frequency / carrier).

[0016] Optionally, determining the CSI associated with the one or more wireless signals by at least one of a plurality of nodes of the second type further includes selecting at least a portion of the determined CSIs to be transmitted. In this case, selecting at least a portion of the determined CSIs to be transmitted can be performed based on at least one of the following: the state of the wireless network, the sensed value to be determined, the capabilities of the node transmitting the CSI and / or the node receiving the CSI, and the size of the extracted CSI in terms of processing, memory, or network requirements. This can be advantageously used to avoid using too many resources, such as avoiding overwhelming the wireless network with messages carrying CSI data.

[0017] In another embodiment, the analysis of at least a portion of the received CSI performed by the node of at least one of the first types of nodes differs from the analysis of other CSI performed by the node of at least one of the first types of nodes. This is advantageous, for example, if the area covered by the signal transmitted between a plurality of second-type nodes (e.g., a specific room or floor of a building) differs from the area covered by other wireless signals (e.g., the general perimeter of a building, such as a residence). Alternatively or additionally, the sensed values ​​may be different (e.g., detecting the presence of a person versus performing respiratory detection).

[0018] In yet another embodiment, at least one of the first-type nodes controls which of a plurality of second-type nodes determines the CSI associated with the wireless signal. Advantageously, this allows the first-type nodes to orchestrate the CSI determination, for example by changing over time which second-type node performs the CSI determination to perform sensing in a specific area (e.g., periodically). This is particularly advantageous if it is necessary to limit traffic in the wireless network and sensing may be limited to a specific area.

[0019] In another embodiment, the node in at least one of the first types of nodes controls the characteristics of transmitting at least a portion of the determined CSI from at least one of a plurality of second types of nodes to the node in at least one of the first types of nodes. The characteristics may include one or more of the following: how often at least a portion of the CSI is transmitted, which portion of the CSI is transmitted, when the CSI is transmitted, and how the CSI is transmitted (e.g., in what format, along with other data).

[0020] In a particularly advantageous embodiment, the wireless network includes a plurality of nodes of a first type, and the method further includes: selecting one or more of the plurality of first-type nodes, transmitting at least a portion of the determined CSI to one or more of the plurality of first-type nodes, such that the selected one or more of the plurality of first-type nodes receive at least a portion of the determined CSI and analyze the received at least a portion of the CSI. This allows for balancing which of the first-type nodes performs the analysis and can be used particularly when performing different types of analysis (e.g., for determining different characteristics of the sensed values) on each first-type node.

[0021] According to a second aspect, a computer program product is provided. The computer program product includes instructions that, when executed by a processor, cause the processor to perform a method according to the first aspect and any embodiment thereof.

[0022] According to a third aspect, a system is provided comprising a wireless network including at least one node of a first type and a plurality of nodes of a second type. The at least one node of the first type is arranged to perform CSI analysis related to wireless signals transmitted in the wireless network. The plurality of nodes of the second type differ from the first type.

[0023] Each of the plurality of second-type nodes is arranged to: transmit one or more radio signals among the plurality of second-type nodes; determine CSI associated with one or more radio signals; and transmit at least a portion of the determined CSI to a node of at least one first-type node.

[0024] Each of at least one node of the first type is further arranged to: receive at least a portion of the determined CSI; and analyze at least a portion of the received CSI, and determine a sensed value based on the analysis.

[0025] According to a fourth aspect, an apparatus is provided. The apparatus serves as a node of a first type in a system according to a third aspect. The apparatus includes: input for receiving at least a portion of a determined CSI from a second type of node; and a processor arranged for analyzing at least a portion of the received CSI, and further for determining a sensed value based on the analysis. Attached Figure Description

[0026] Referring to the accompanying drawings, these and other aspects of the invention will be clear and further illustrated by way of example, in which:

[0027] Figure 1 A first system according to the prior art is shown, which has a limited sensing coverage range;

[0028] Figure 2 A second system based on existing technology is shown, which requires the use of many expensive nodes;

[0029] Figure 3 A system for performing sensing in a wireless network, according to the first aspect, is shown;

[0030] Figure 4 It shows Figure 3 The characteristics of the system shown;

[0031] Figure 5 An embodiment of the system according to the first aspect is shown, which includes a plurality of nodes of a first type;

[0032] Figure 6 The characteristics of a system including many second-type nodes are shown;

[0033] Figure 7An embodiment of the system according to the first aspect is shown, which solves the problem Figure 6 The characteristics shown; and

[0034] Figure 8 This is a block diagram of a method for performing sensing in a wireless network.

[0035] Corresponding elements in the accompanying drawings are represented by the same reference numerals. Detailed Implementation

[0036] Figure 1 A building (house 100 in this example) is shown, comprising a first area 115 (e.g., the ground floor) and a second area 120 (e.g., floors above the ground floor). A first wireless network sensing system 105, according to prior art, is installed in house 100. System 105 includes a first type of node 110 and two second type nodes 120, 130. The first type of node 110 is capable of processing channel state information (CSI) associated with wireless links within the wireless network sensing system 110 and determining the presence of any person based on this analysis. The second type of nodes 120, 130 do not analyze CSI because they may be unable to do so due to limitations such as memory or processing power, or other constraints. The second type of nodes may be relatively cheaper than the first type of nodes due to reduced requirements given that these nodes do not need to be able to perform CSI analysis.

[0037] The advantage of the first system 105 according to the prior art is that it is relatively inexpensive because it only requires a single node 110 of the first type. However, the signals transmitted within system 105 that can be used to perform sensing based on CSI analysis are limited to first signals 112 and second signals 114, which are respectively associated with the links between the first type node 110 and the second type first node 120 and the second type second node 130. As a result, based on the analysis of CSI, a first person A and a third person C can be detected in residence 100; however, a second person B may not be detected because the second person does not sufficiently influence links 112 and 114.

[0038] Figure 2 A second wireless network sensing system 205 according to the prior art is shown. In this system 205, there are three nodes of a first type: 110, 220, and 230. Each of these nodes can analyze the link-related CSI between each node. Because a third signal 225 related to the link between the second node 220 of the first type and the third node 230 of the first type now exists, a second person B can also be detected, because it differs from... Figure 1 System 105 is now affected by link 225.

[0039] The advantage of this second system 205 according to the prior art is that it provides a greater coverage area for sensing in house 100. However, it is relatively expensive because, compared to [other systems]... Figure 1 Compared to the existing first wireless network sensing system 105, it requires more first-type nodes.

[0040] exist Figure 3 The image shows a system 305 according to an embodiment of the first aspect. The system 305 includes a first node 310 of a first type and two nodes 320, 330 of a second type. Similar to... Figure 1 In the system shown, the first node of the first type analyzes the CSI associated with each link 312, 314 of the first node and the second nodes 320, 330 of the second type. Although the second type of nodes cannot analyze the CSI associated with the link 325 between them, signals are transmitted between the first and second nodes 320, 330 of the second type. The determination of the CSI of this signal 325 can be made by one of the second type nodes 220, 230.

[0041] like Figure 4 As shown, CSI associated with one or more wireless signals transmitted between nodes 320 and 330 of the second type is extracted, and at least a portion of the CSI is transmitted by one of the nodes 330 of the second type to node 310 of the first type via link 410. Whether one or both nodes of the second type transmit CSI data can be determined in various ways; for example, each node of the second type can independently determine whether to transmit the extracted CSI to node 310 of the first type, or the nodes 320 and 330 of the second type can determine this together, for example, in a master / slave configuration, or node 110 of the first type can poll or instruct nodes 220 and 230 of the second type to transmit at least a portion of the extracted CSI.

[0042] The first type of node 310 then analyzes at least a portion of the received CSI, which is related to the wireless signal transmitted between the second type of nodes 320 and 330. Therefore, the system 305 is able to, for example, detect... Figure 3 This shows all three people A, B, and C, but only requires at least one node of type 1. This provides Figure 1 The lower cost advantage of the system 105 shown, and Figure 2 The system 205 shown has the advantage of a larger coverage area.

[0043] Despite Figure 4 The system 305 shown only requires a single node of type 1, but as Figure 5As shown in system 505, there can be multiple first-type nodes 310, 540. One of the second-type nodes 330 transmits at least a portion of the CSI to one or both of the first-type nodes 310, 540. Which of the first-type nodes(s) to which the extracted CSI is transmitted can be determined autonomously by the second-type nodes, or can be predetermined by the first-type nodes, user-configured, set, etc. Transmitting only a portion of the determined CSI to a single first-type node reduces the bandwidth required to transmit this data in the wireless network. By transmitting at least a portion of the determined CSI to multiple first-type nodes, each such first-type node can track changes in the determined CSI over time, or each such node can use different algorithms to perform sensing; for example, a first-type node can determine a value indicating a person moving around the area based on analysis of the extracted CSI, while a second-type node can determine a value indicating a person breathing; furthermore, these determined values ​​can be used together to determine a value indicating the presence of a person.

[0044] Figures 3-5 The example provided only shows two nodes of the second type. (See example from...) Figure 5 The examples provided show that there can be more than one node of type 1. In fact, there can be any number of nodes of type 1, as long as there is at least one. There can also be any number of nodes of type 2, as long as there are multiple (i.e., at least two) nodes of type 2. Figure 6 The diagram illustrates a system 605 comprising four second-type nodes 620, 630, 650, and 660. In this system 605, each second-type node creates a link with every other node of the second type, and further, a first-type node 310 creates a link with each of the second-type nodes 620, 630, 650, and 660. This creates a large number of links 600, which can, for example, allow for the expansion of the coverage area where sensing is performed; however, this may also be detrimental to improving sensing, for example, when the wireless network becomes congested, when latency increases, or when messages are lost.

[0045] exist Figure 7 In the middle, it was shown again Figure 6The system 605, however, has a limited number of links between sensing devices. In this example, three different wireless signals 710, 720, and 730 are each transmitted between two nodes 620, 630, 650, and 660 of the second type. Although optional, this allows a message to be sent from the first node 620 to the second node 650 so that the second node determines the CSI associated with its link to the first node and sends at least a portion of that CSI as message 720 to the third node 630. The third node 630 can then determine the CSI associated with its link to the second node 650 and transmit at least a portion of that CSI, along with CSI data received from the second node 650 associated with its link 710 with the first node 620, to the fourth node 660. Finally, the fourth node 660 can again determine the CSI associated with its link 730 with the third node and transmit at least a portion of the CSI it has determined to the first type node 740. The fourth node 660 will further send the CSI data it has already received from the third node to the first-type node, which includes the CSI data that the third node has already received from the second node. The first-type node 310 can then analyze the CSI data associated with each of the three links 710, 720, and 730 mentioned above. Furthermore, the first-type node 310 can extract and analyze the CSI data associated with its link 740 with the second-type fourth node 660.

[0046] exist Figure 8 The diagram illustrates an example of a method 800 for performing sensing in a wireless network. The wireless network includes at least one node of a first type and a plurality of nodes of a second type, different from the first type, arranged to perform CSI analysis related to wireless signals transmitted in the wireless network. The method includes:

[0047] - Transmit one or more 810 wireless signals between multiple Type II nodes;

[0048] - The CSI associated with one or more wireless signals is determined by at least one of a plurality of second-type nodes;

[0049] - At least a portion of the CSI determined by 830 is transmitted from at least one of a plurality of second-type nodes to at least one of a plurality of first-type nodes;

[0050] - The node in at least one of the first type of nodes receives at least a portion of the CSI determined by 840; and

[0051] - At least a portion of the CSI received by 850 is analyzed by at least one of the nodes of the first type, and the sensing value of 860 is determined based on the analysis.

[0052] Various embodiments of the present invention can be implemented as a program product for use with a computer system, wherein the program(s) of the program product define the functionality of the embodiments (including the methods described herein). In one embodiment, the program(s) may be contained on a variety of non-transitory computer-readable storage media, wherein, as used herein, the expression “non-transitory computer-readable storage media” includes all computer-readable media, with the sole exception of transient propagation signals. In another embodiment, the program(s) may be contained on a variety of transient computer-readable storage media. Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media on which information is permanently stored (e.g., read-only memory devices within a computer, such as CD-ROM discs readable by a CD-ROM drive, ROM chips, or any type of solid-state non-volatile semiconductor memory); and (ii) writable storage media on which changeable information is stored (e.g., flash memory, floppy disks within a floppy disk drive or hard disk drive, or any type of solid-state random access semiconductor memory). The computer program may run on a processor.

[0053] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that, when used in this specification, the term “comprising” specifies the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0054] All the means or steps plus functional elements in the following claims are intended to include any structure, material, action, and equivalent for performing a function in combination with other claimed elements as specifically claimed. Descriptions of embodiments of the invention have been shown for illustrative purposes, but are not intended to be exhaustive or limited to the embodiments in the disclosed forms. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Embodiments have been chosen and described in order to best explain the principles of the invention and some practical applications, and to enable others skilled in the art to understand the invention with respect to various embodiments with various modifications suitable for particular intended uses.

Claims

1. A method for performing sensing in a wireless network, the wireless network comprising at least one node of a first type arranged for performing analysis of channel state information related to wireless signals transmitted in the wireless network, the wireless network further comprising a plurality of nodes of a second type different from the first type, and the method comprising: transmitting one or more wireless signals between the plurality of nodes of the second type; determining, by at least one of the plurality of nodes of the second type, channel state information related to the one or more wireless signals transmitted between the plurality of nodes of the second type; transmitting, by the at least one of the plurality of nodes of the second type, one or more further wireless signals to a node of the at least one node of the first type, the one or more further wireless signals comprising at least a portion of the determined channel state information related to the one or more wireless signals transmitted between the plurality of nodes of the second type; receiving, by the node of the at least one node of the first type, the one or more further wireless signals comprising at least a portion of the determined channel state information related to the one or more wireless signals transmitted between the plurality of nodes of the second type; determining, by the node of the at least one node of the first type, further channel state information related to the one or more further wireless signals transmitted between the at least one of the plurality of nodes of the second type and the node of the at least one node of the first type; analyzing, by the node of the at least one node of the first type, the following two: - at least a portion of the received channel state information related to the one or more wireless signals transmitted between the plurality of nodes of the second type, and - the determined further channel state information related to the one or more further wireless signals transmitted between the at least one of the plurality of nodes of the second type and the node of the at least one node of the first type; and determining, by the node of the at least one node of the first type, a sensing value based on the analysis. The sensing value is indicative of movement of an object in a sensing area, the sensing area being defined at least by locations of a plurality of nodes of the plurality of nodes of the second type.

2. The method of claim 1, wherein, Determining, by the at least one of the plurality of nodes of the second type, channel state information related to the one or more wireless signals comprises extracting a plurality of time series values from a communication stack of the at least one of the plurality of nodes of the second type.

3. The method of claim 1 or 2, wherein, Determining, by the at least one of the plurality of nodes of the second type, channel state information related to the one or more wireless signals further comprises selecting a frequency or periodicity at which the channel state information is extracted.

4. The method of claim 3, wherein, Determining, by the at least one of the plurality of nodes of the second type, channel state information related to the one or more wireless signals further comprises selecting at least a portion of the determined channel state information to be transmitted.

5. The method of claim 3, wherein, ​ 6. The method of claim 5, wherein, The selecting of the at least part of the determined channel state information to be transmitted is performed based on at least one of a status of the wireless network, a sensed value to be determined, and an amount of extracted channel state information.

7. The method of claim 1 or 2, wherein, The analysis of the at least part of the received channel state information performed by the node of the at least one first type of nodes is different from an analysis of further channel state information performed by the node of the at least one first type of nodes.

8. The method of claim 1 or 2, wherein, The node of the at least one first type of nodes controls which at least one of the plurality of second type of nodes determines channel state information related to the wireless signal.

9. The method of claim 1 or 2, wherein, The node of the at least one first type of nodes controls a characteristic of the transmission of the at least part of the determined channel state information by the at least one of the plurality of second type of nodes to the node of the at least one first type of nodes.

10. The method of claim 1, wherein, The wireless network comprises a plurality of first type of nodes, and wherein the method further comprises: selecting one or more of the plurality of first type of nodes to which the at least part of the determined channel state information is transmitted, such that the one or more of the selected plurality of first type of nodes receives the at least part of the determined channel state information, and analyzing the at least part of the received channel state information.

11. A computer program product comprising instructions which, when executed by a processor, cause the processor to carry out the method according to any one of the preceding claims.

12. A system comprising a wireless network, the wireless network comprising: at least one first type of nodes arranged for performing an analysis of channel state information related to wireless signals transmitted in the wireless network, and a plurality of second type of nodes different from the first type, wherein each of the plurality of second type of nodes is arranged for: transmitting one or more wireless signals between the plurality of second type of nodes; determining, by at least one of the plurality of second type of nodes, channel state information related to the one or more wireless signals transmitted between the plurality of second type of nodes; and transmitting, by the at least one of the plurality of second type of nodes, one or more further wireless signals to a node of the at least one first type of nodes, the one or more further wireless signals comprising at least part of the determined channel state information related to the one or more wireless signals transmitted between the plurality of second type of nodes; wherein each of the at least one first type of nodes is further arranged for: receiving the one or more further wireless signals, the one or more further wireless signals comprising at least part of the determined channel state information related to the one or more wireless signals transmitted between the plurality of second type of nodes; determining further channel state information related to the one or more further wireless signals transmitted between the at least one of the plurality of second type of nodes and the node of the at least one first type of nodes, and ​ to analyse both the received at least part of the channel state information and the further channel state information in relation to one or more wireless signals transmitted between a plurality of nodes of a second type, and to determine a sensing value based on said analysis.

13. A device for use as a node of a first type in a system according to claim 12, the device comprising: an input for receiving from a node of a second type at least part of determined channel state information; and a processor arranged to analyse both the received at least part of the channel state information and the further channel state information, and further to determine a sensing value based on said analysis.

14. A node of a second type for use in a system according to claim 12, the node comprising: an input for receiving from a node of a first type at least part of further channel state information; and a processor arranged to determine a sensing value based on said received at least part of further channel state information.

15. A node of a first type for use in a system according to claim 12, the node comprising: an input for receiving from a node of a second type at least part of determined channel state information; and a processor arranged to analyse both the received at least part of the channel state information and the further channel state information, and further to determine a sensing value based on said analysis.

16. A node of a second type for use in a system according to claim 12, the node comprising: an input for receiving

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