Pairing allocation device for RF sensing nodes of an RF context sensing arrangement

Abstract

The invention relates to a pairing allocation device (100) comprising a sensing node position determination unit (102) configured to determine position information (P.I.) related to respective positions of external RF sensing nodes (104, 106) relative to a predefined sensing volume (108) of an RF context sensing arrangement; and a pairing allocation unit (110) configured to allocate at least one transmitter-receiver pair between the respective RF sensing nodes of the RF context sensing arrangement using the determined position information to perform an RF context sensing function, and to assign a transmitter role (Tx) and a receiver role (Rx) to the RF sensing nodes of a given transmitter-receiver pair, respectively. The pairing allocation device then provides pairing information indicative of the at least one allocated transmitter-receiver pair and the allocated transmitter and receiver roles, and thus enables to increase the tolerance of the RF context sensing arrangement to position changes of a movable object.

Description

TECHNICAL FIELD

[0001] The present invention relates to a pair assignment device for an RF context sensing arrangement, a context sensing control device, an RF context sensing arrangement, a method for controlling operation of a pair assignment device, a context sensing control device and an RF context sensing arrangement, and a computer program. BACKGROUND

[0002] US2019 / 0051342 A1 discloses a system and method for detecting or sensing human presence without fiducial elements, which uses signal absorption of radio frequency waves caused by the presence of biological matter in a communication network comprising RF sensing nodes, as well as signal forward scattering and reflection backscattering.

[0003] DE 102014211237 A1 discloses a method of detecting a state of a room. The method comprises the steps of: assigning at least one time slot to each radio device of a second plurality of radio devices arranged in or at a space; transmitting, by each radio device, a radio signal into the space (R) within the time slot assigned to the radio device; receiving, by at least a portion of the radio devices, the transmitted radio signal; determining, by each radio device, a channel information value indicative of a signal strength of the received radio signal; associating, by each wireless device (12-i), each specific channel information value with a pair of wireless devices based on the assigned time slot; and detecting (S09) the state of the space (R) in real time based on the channel information values associated with the pairs of wireless devices and using a predetermined evaluation model. SUMMARY

[0004] The RF context sensing arrangement typically depends on comparing a current value of a predetermined RF signal metric, which can be influenced by the presence of biological matter within the sensing volume, with a previously established baseline or reference value. The baseline is associated with a given pair of RF sensing nodes - the given pair of RF sensing nodes being formed by one RF sensing node operating as a transmitter and the other RF sensing node operating as a receiver - i.e. with a given wireless communication link between two different RF sensing nodes.

[0005] Sensing the presence of movable objects within the sensing volume can impact the performance of the RF context sensing arrangement, such as the presence sensing arrangement. Although RF signals are able to penetrate objects, the relative attenuation suffered by the RF signals is also influenced by the sensing volume and the objects or objects located therein, e.g. how close the object is to the transmitter or receiver. RF signals can take multiple paths from the transmitter to the receiver before being properly decoded. If there is an object close to the transmitter, then at least some of the paths from the transmitter to the receiver are influenced by that object and are therefore attenuated. On the other hand, if the object is further away, then the attenuation suffered by the RF signals when passing through the object is the same, but there are other paths that do not pass through the object (e.g. bounce off a wall and avoid the object) and are therefore not attenuated. When the receiver collects all of these paths, objects that are further away from the transmitter also appear to have less attenuation. The opposite is also valid: objects that are very far from the transmitter but very close to the receiver will result in higher attenuation, because a large portion of the signals will pass through the object before being properly received, no matter which path they take. In other words, RF signals emitted from (or received by) a transmitter that is in a position very close to a given object are more attenuated than if the object were located further away.

[0006] As the performance of the RF context sensing arrangement depends on how accurately the baseline values represent the sensing volume, and RF signals are influenced by the objects present within their propagation path, it would be beneficial to enable increasing the tolerance of the RF context sensing arrangement to changes in the position of movable objects.

[0007] According to a first aspect of the present application, a pairing allocation device is disclosed. The pairing allocation device comprises a sensing node position determination unit configured to determine position information related to respective positions of external RF sensing nodes with respect to a predefined sensing volume of an RF context sensing arrangement.

[0008] The pairing allocation device further comprises a pairing allocation unit connected to the sensing node position determination unit, and the pairing allocation unit is configured to allocate at least one transmitter-receiver pair among the respective RF sensing nodes of the RF context sensing arrangement for performing an RF context sensing function using the determined position information, to assign a transmitter role and a receiver role to the RF sensing nodes of a given transmitter-receiver pair, respectively, and to provide pairing information indicative of the at least one allocated transmitter-receiver pair and the assigned transmitter and receiver roles.

[0009] In an RF context sensing arrangement comprising n transceivers acting as RF sensing nodes, each transceiver is communicatively connected with all other transceivers, n! / (n-2)! different wireless communication links are in principle available to perform the RF presence sensing function, since each RF sensing node can take a transmitter role or a receiver role. The pairing assignment device is advantageously configured to assign one or more appropriate transmitter-receiver pairs to perform the RF context sensing function based on the determined location information. This way, an increase in reliability of the results of the RF context sensing function can be achieved.

[0010] In the following, embodiments according to the first aspect of the application will be described.

[0011] In computer science, context awareness or context sensing refers to the idea that devices can both sense and react based on their environment. Devices can have information about the conditions under which they are able to operate and react accordingly based on rules or intelligent stimuli. Context aware devices can also try to make assumptions about the current situation of a user. Context is generally defined as "any information that can be used to characterize the situation of an entity".

[0012] The RF context sensing arrangement and the corresponding sensing function are in different embodiments directed to presence sensing, respiration detection, sleep detection (in particular REM vs. non-REM detection), fall detection, etc. Depending on the technology used by the corresponding arrangement, gestures and heartbeats can be detected using appropriate RF context sensing arrangements, such as for example an arrangement using RF signals according to the 60GHz WiFi communication protocol for the RF context sensing function.

[0013] In another embodiment, the pairing assignment unit is further configured to assign both a transmitter role and a receiver role to the RF sensing nodes of a given transmitter-receiver pair. In this embodiment, both RF sensing nodes of the assigned transmitter-receiver pair are assigned both roles, so that each RF sensing node is able to perform the RF context sensing function based on the RF signals provided by the other RF sensing node. Thus, in this embodiment, it is not always one of the RF sensing nodes of the assigned pair that transmits alone and the other that receives, and the given transmitter-receiver pair results in two different communication links to perform the context sensing function. In a particular embodiment, the transmitter and receiver roles of the RF sensing nodes assigned to a given transmitter-receiver pair are dynamically changed, so that the RF sensing nodes take turns transmitting and receiving to perform the context sensing function.

[0014] The appropriate location information related to the predefined sensing volume of the external RF-sensing node relative to the RF-context sensing arrangement is any information that indicates the location of the RF-sensing node within the sensing volume. For example, it can indicate the height at which the RF-sensing node is installed (relative to the floor). The location information can for example comprise tags associated with the RF-sensing node that indicate the location at which the RF-sensing node is positioned. Examples of such tags include, but are not limited to: "wall switch", "desk lamp" or "table lamp", which indicate that the RF-sensing node is a switch on a wall or that the RF-sensing node is a lamp positioned on a desk or table and thus can be located at waist or chest height; "fire sensor", "high-bay luminaire" or "exit sign", which indicate that the RF-sensing node is located at about ceiling height; "outlet", "flood sensor", which indicate that the RF-sensing node can be positioned close to the floor; "wardrobe", "drawer", which indicate that the RF-sensing node is located inside a piece of furniture that can be opened or closed; and so on. Further, tags such as "battery-powered device" or "swing arm lamp" indicate that the associated device is a movable device, whose location within the sensing volume can change during operation.

[0015] Embodiments of the pairing distribution device advantageously comprise a tag memory, wherein the tags are associated with a predicted location.

[0016] In embodiments, the location information is determined by the pairing distribution device by evaluating one or more images of the sensing volume and identifying the relative location of the RF-sensing node relative to other RF-sensing nodes. Preferably, the image is a photographic image or a combination of photographic images that form a panoramic image of the sensing volume, and the evaluation is performed automatically by suitable software based on object recognition algorithms or based on user input or a combination of both. For example, the software and / or the user can associate objects represented in the image with suitable tags and locate the position of the RF-sensing node within the sensing volume. Information about the size or dimensions of the sensing volume is also determined by the software or by means of user input. In a particular embodiment, the image is provided by a 3D time-of-flight camera, wherein the size information of the sensing volume is readily extracted from the image. In another particular embodiment, the relative positions of the lamps are provided by a room mapping application utilizing a camera of an external device, such as but not limited to a robotic vacuum cleaner.

[0017] In an alternative preferred embodiment, the location information is received by the pairing distribution device from an external location information source, for example from the commissioning device. In this embodiment, the pairing distribution device comprises an input unit connected to the sensing node location determination unit and is configured to receive location input data indicative of the location information.

[0018] Therefore, by using appropriate selection rules, location information makes it possible to select transmitter-receiver pairs that are less affected by or more tolerant of the possible movement of objects within the sensing volume.

[0019] In one embodiment, the pairing assignment device further includes an output unit configured to provide an assigned pairing signal indicating pairing information. In another embodiment, the assigned pairing signal is provided to RF sensing nodes so that they are aware of whether they have been assigned a role, i.e., a transmitter or receiver role. In yet another embodiment, the assigned pairing signal is provided to an external control device to control the performance of the RF context sensing function in the context sensing arrangement.

[0020] In another embodiment, the pairing and assignment device further includes an environmental information determination unit configured to determine environmental information relating to one or more objects present in the sensing volume. In embodiments including the environmental information determination unit, the pairing and assignment unit is also connected to the environmental information determination unit and configured to also use the determined environmental information to assign at least one transmitter-receiver pair and transmitter and receiver roles.

[0021] Appropriate environmental information indicates the number and corresponding locations of objects within the sensing volume. Preferably, it also indicates the material used to manufacture the objects and the confidence level of the likelihood that the objects are moving or stationary. Environmental information can be provided by analyzing panoramic images and labeling the objects in the images, or by using a 3D time-of-flight camera. Environmental information may, for example, include tags associated with the objects that indicate the object's properties, material, size, or any combination thereof.

[0022] In a particular embodiment, environmental information is determined by an environmental information determination unit, for example, by evaluating one or more images of a sensed volume and identifying objects located therein. In an alternative preferred embodiment, environmental information is received by a pairing and allocation device from an external device (e.g., from a network access initialization device). In this embodiment (where environmental information is received from an external device), the pairing and allocation device includes an input unit connected to the environmental information determination unit and configured to receive location input data indicating location information. In a preferred embodiment, this input unit is the same input unit also used to receive location information.

[0023] In another embodiment, environmental information is provided alternatively or additionally by an additional data source. An example of a suitable additional data source is a microphone that acoustically monitors a specific volume. Such monitoring data provided by the microphone can be used to determine whether a specific predetermined event that has a potential impact on RF context sensing functionality has occurred. For example, the data source can receive signals from the microphone and, for example, use pre-stored microphone data patterns to identify whether a car is entering a garage, or large pieces of furniture are being moved in a particular room, or a door to a given room is being opened or closed, and provide environmental information indicating this. Alternatively, environmental information is provided by a surveillance system such as an indoor security camera system.

[0024] The typical actions expected to be taken within the sensing volume can also influence RF context sensing functionality. For example, using a transmitter-receiver pair formed by RF sensing nodes (located at chest height based on determined location information) is generally preferred because it maximizes the chance of detecting a person in the sensing volume by providing the highest signal-to-noise ratio for accurate detection (e.g., for breathing or heart rate detection). However, if the sensing volume is, for example, an office, the room can be expected to have many monitors, laptops, drawers, piles of documents, etc. (all of which are also located at waist or chest height, and therefore potentially affect RF sensing functionality when using RF sensing nodes located at waist or chest height). In office spaces, people tend to spend time sitting. Therefore, assigning a transmitter-receiver pair located closer to the floor potentially yields richer or more sensitive data for performing RF context sensing functionality. However, in other embodiments, however, a transmitter-receiver pair is assigned where one RF sensing node is near the floor and the other is near the ceiling.

[0025] Furthermore, in this embodiment, the environmental information determination unit is also configured to determine intended use information indicating the intended use of the sensing volume. In this embodiment, the pairing assignment unit is also configured to use the intended use information to assign at least one transmitter-receiver pair and transmitter and receiver roles. The intended use information is preferably provided as a tag (such as "office," "bedroom," "living room," "parking lot," etc.) and used to determine at least one transmitter-receiver pair.

[0026] In another embodiment, intended use information is used to appropriately assign transmitter-receiver pairs, also based on the expected occupancy of the room. For example, when a user is not in the room but a pet (e.g., a cat) can still move freely in one or more rooms, the pairing assignment device is configured to assign another transmitter-receiver pair that is more suitable for detecting the pet.

[0027] A second aspect of the invention is formed by a context sensing control device. The context sensing control device includes a pairing assignment device according to a first aspect of the invention. The context sensing control device also includes a baseline storage unit configured to store a baseline associated with at least one transmitter-receiver pair to perform an RF context sensing function.

[0028] The context sensing control device also includes a context determination unit connected to the baseline storage unit and the pairing allocation device. The context determination unit is configured to determine a signal quality value indicating a predetermined RF signal metric, received by the RF sensing node acting as a receiver and transmitted by the RF sensing node acting as a transmitter, the RF signal metric being susceptible to the presence of a living organism in the sensing volume. The context determination unit is further configured to use the determined signal quality value and the corresponding baseline to determine whether a predetermined contextual situation has occurred or is currently occurring.

[0029] The context-sensing control device of the second aspect shares the advantages of the pairing and allocation device of the first aspect. Embodiments of the context-sensing control device include additional features of the pairing and allocation device of the first aspect.

[0030] Further embodiments of the context sensing control device of the second aspect of the present invention will be described below.

[0031] In a particular embodiment, the baseline is a single value. In an alternative embodiment, the baseline values ​​associated with n RF sensing nodes are stored as an n×n matrix, or in embodiments where the baseline values ​​are associated with a specific period T, they are stored as an n×n×T matrix.

[0032] In one embodiment, the context sensing control device includes a pairing and assignment device integrated into the same housing. In an alternative embodiment, the pairing and assignment device is not physically integrated into the same housing, but is a separate device communicatively connected to the context determination unit.

[0033] In one embodiment, the predetermined RF signal metric is a Received Signal Strength Indication (RSSI) value, which is an estimated measurement indicating the power level that one RF sensing node is receiving from another RF sensing node. In an alternative embodiment, the RF signal metric additionally or alternatively indicates a bit error rate value or a metric based on information accessible via a given Channel State Information (CSI) (e.g., line-of-sight component, channel gain, etc.).

[0034] In one embodiment, the predetermined context is whether an object (such as a person) is present or moving within the sensing volume; that is, the context-aware sensing function is an presence sensing function, and the context determination unit is an presence determination unit. In an alternative embodiment, the predetermined context includes breathing, sleep state, falling, gestures, heartbeat, etc.

[0035] In a particular embodiment, the baseline storage unit is further configured to store multiple baselines that are determined at different times and associated with corresponding different locations of one or more objects present in the sensing volume and with corresponding transmitter-receiver pairs. In this embodiment, the detection determination unit is configured to use a signal quality value and a corresponding one of the multiple stored baselines associated with the transmitter-receiver pair to determine multiple detection events, and to use the multiple determined detection events to determine whether a predetermined contextual situation has occurred or is currently occurring (such as, for example, whether an object exists in the sensing volume).

[0036] For example, and to improve the reliability of the results of RF context-aware sensing functions (especially RF presence sensing functions), during the network access initialization phase, several baselines are determined and stored for one or more pairs of RF sensing nodes, preferably considering both the transceiver and receiver roles of each RF sensing node in a given pair. Each baseline is determined at a different point in time and is associated with a corresponding different location of one or more objects present in the sensing volume. This means that at least one pair has multiple associated baselines, one for each of the different spatial configurations of objects within the sensing volume, and the different locations of objects (such as multiple pieces of furniture) will have an impact on the baseline determined in each case. The detection determination unit of the presence sensing control device is advantageously configured to determine multiple detection events when performing the RF context sensing function, using a signal quality value and a corresponding one of the multiple stored baselines associated with the transmitter-receiver pair assigned by the pairing allocation device. For a given baseline among the multiple baselines associated with a pair of RF sensing nodes, if the pair of RF sensing nodes is an assigned transceiver-receiver pair, a detection event is determined when the determined signal quality value indicates the presence of an object. The context sensing control device is configured to use multiple defined detection events to determine whether a predetermined context has occurred, such as whether an object exists in the sensing volume.

[0037] In a particular embodiment, the context sensing control device is configured to use a plurality of determined detection events with corresponding predetermined weighting factors, the corresponding predetermined weighting factors indicating the probability of each scenario associated with each baseline occurring during the expected use of the sensing volume. Additionally or alternatively, in another embodiment, some RF sensing node pairs and corresponding baselines can be used as backups, such that when in doubt (i.e., when a determined signal quality value is within a predetermined range of uncertainty around the baseline), the RF presence sensing function can be supplemented to confirm or reject the detection hypothesis using other baselines associated with that transmitter-receiver pair.

[0038] According to a third aspect of the invention, an RF context sensing arrangement is described. The RF context sensing arrangement includes: at least two RF sensing nodes configured to transmit and receive RF signals and determine and provide signal quality values ​​indicating a predetermined RF signal metric of the RF signals received by the respective RF sensing nodes; and a context sensing control device according to a second aspect of the invention.

[0039] Therefore, the RF context sensing arrangement of the third aspect shares the advantages of the pairing allocation device of the first aspect or any embodiment thereof, as well as the advantages of the context sensing control device of the second aspect or any embodiment thereof.

[0040] An embodiment of the RF context sensing arrangement will be described below.

[0041] In a preferred embodiment, the RF context sensing arrangement is an RF-controlled lighting arrangement. The RF sensing nodes in this embodiment not only perform RF sensing functions but also form luminaires or lighting equipment, switches, sensors (such as temperature sensors, humidity sensors, window or door sensors), smoke detectors, access points, etc. The operation of such RF sensing nodes is preferably wirelessly controllable, and control signals transmitted simultaneously via a wireless communication network are used as RF signals from which RF signal metrics are determined. The assignment of transmitter and receiver roles applies to the context sensing function but not necessarily to the communication function between RF sensing nodes; that is, RF signal nodes can communicate with each other to perform communication functions, but only those RF signals provided by the RF sensing nodes of a given transmitter-receiver pair with the transmitter role and received by the RF sensing nodes of the receiver pair are used for the context sensing function.

[0042] In this embodiment, when an RF signal is received from an RF sensing node that has been assigned as a transmitter in a given transmitter-receiver pair, only those RF sensing nodes that have been assigned as receivers in that pair provide signal quality values. The RF sensing nodes are aware of their assigned roles either because they have directly received the assigned pair signal or because they have been accordingly instructed by another device (such as a hub). The context determination unit then receives the signal quality values ​​and, using a stored corresponding baseline, determines whether a predetermined contextual situation has occurred or is currently occurring (such as, for example, the presence of a person in the sensing volume). This embodiment reduces the amount of signal provided to the context determination unit but increases the complexity of the RF sensing nodes.

[0043] In an alternative embodiment, the RF sensing node provides a signal quality value (determined using information associated with the transmitting RF sensing node that has transmitted an RF signal from which the signal quality value has been determined). The context determination unit receives all signal quality values, but for the RF context sensing function, in response to RF signals provided by RF sensing nodes of correspondingly assigned transmitter-receiver pairs with transceiver roles, only the signal quality values ​​provided by one or more assigned transmitter-receiver pairs with receiver roles are used. In this embodiment, the RF sensing nodes provide signal quality values ​​independently of their assigned roles (if any), thus reducing complexity. However, the presence detection unit is relatively more complex because it must select appropriate signal quality values ​​to perform the RF context sensing function.

[0044] In another embodiment, the RF sensing node acting as a transmitter is also configured to determine and provide a signal quality value that indicates a predetermined RF signal metric of the RF signals (i.e., echo RF signals) provided and received by itself. This is generally not desirable for communication functions as it creates additional overhead, but it is suitable for improving signal quality determination by having additional relevant data. Rapid generation of such data is particularly advantageous in the detection of fast events (e.g., a person falling, gesture detection, etc.). In this embodiment, a corresponding baseline for such echo RF signals is also determined and stored. In a particular embodiment, one or more RF sensing nodes suitable for determining the signal quality value of the echo RF signals are WiFi-compatible devices (such as WiFi mesh routers) configured to simultaneously communicate (talk) on a first radio channel and receive on a second radio channel different from the first radio channel.

[0045] A fourth aspect of the invention is formed by a method for operating a pairing and allocation device, particularly for an RF context sensing arrangement. The method includes...

[0046] - Determine the location information related to the corresponding position of the external RF sensing node relative to the predefined sensing volume of the RF context sensing arrangement;

[0047] - Using the determined location information, allocate at least one transmitter-receiver pair among the various RF sensing nodes in the RF context sensing deployment to perform RF context sensing functions, and assign transmitter and receiver roles to the RF sensing nodes of a given transmitter-receiver pair, respectively; and

[0048] - Provides pairing information indicating at least one assigned transmitter-receiver pair and the assigned transmitter and receiver roles.

[0049] In an embodiment of the method in the fourth aspect, the method further includes: determining environmental information relating to one or more objects present in the sensing volume; and also using the determined environmental information to assign at least one transmitter-receiver pair and transmitter and receiver roles.

[0050] A fifth aspect of the invention is formed by a method for operating a context-sensing control device. The method includes:

[0051] - A method for performing the fourth aspect of the present invention;

[0052] - For at least one transmitter-receiver pair, store the baseline associated with it;

[0053] - Determine a signal quality value, which indicates a predetermined RF signal metric, received by the RF sensing node acting as a receiver and transmitted by the RF sensing node acting as a transmitter, the RF signal metric being susceptible to the presence of organisms in the sensing volume; and

[0054] - Using the determined signal quality value and the corresponding baseline, determine whether the predetermined context has already appeared in the sensing volume.

[0055] A sixth aspect of the invention is formed by a method for operating an RF context sensing arrangement. The method includes:

[0056] - A method for performing the fourth aspect of the present invention;

[0057] - Determine and provide a signal quality value that indicates a predetermined RF signal metric of at least one RF signal received by an RF sensing node of a transmitter-receiver pair with receiver functionality and provided by an RF sensing node of a transmitter-receiver pair with transmitter functionality;

[0058] - For at least one transmitter-receiver pair, store the baseline associated with it;

[0059] - Determine a signal quality value, which indicates a predetermined RF signal metric, received by the RF sensing node acting as a receiver and transmitted by the RF sensing node acting as a transmitter, the RF signal metric being susceptible to the presence of organisms in the sensing volume; and

[0060] - Using the determined signal quality value and the corresponding baseline, determine whether the predetermined context has already appeared in the sensing volume.

[0061] Therefore, the methods of the fourth, fifth and sixth aspects of the present invention share the advantages of the pairing allocation device, context sensing control device and RF context sensing arrangement of the first, second and third aspects of the present invention, respectively.

[0062] According to a seventh aspect of the present invention, a computer program is disclosed. The computer program includes instructions that, when executed by a computer, cause the computer to perform the method of the fourth aspect of the present invention.

[0063] It should be understood that the pairing and allocation device of claim 1, the context sensing control device of claim 7, the RF context sensing arrangement of claim 9, the methods for operating the pairing and allocation device, the context sensing control device and the RF context sensing arrangement of claims 10, 12 and 13 respectively, and the computer program of claim 14 have similar and / or identical (especially as defined in the dependent claims) preferred embodiments.

[0064] It should be understood that the preferred embodiments of the present invention may also be any combination of the dependent claims or the above embodiments with the corresponding independent claims.

[0065] These and other aspects of the invention will become apparent and will be explained with reference to the embodiments described below. Attached Figure Description

[0066] In the following figures:

[0067] Figure 1A A schematic block diagram of an embodiment of a paired distribution device that is communicatively connected to a pair of RF sensing nodes within a sensing volume is shown.

[0068] Figure 1A A schematic diagram of one embodiment of an RF context sensing arrangement is shown.

[0069] Figure 2 A schematic diagram of another embodiment of the RF context sensing arrangement is shown.

[0070] Figure 3 A schematic diagram of another embodiment of the RF context sensing arrangement is shown.

[0071] Figure 4 A schematic diagram of another embodiment of an RF context-sensing arrangement for determining (associated with corresponding different room configurations (i)-(iv)) is shown.

[0072] Figure 5 A flowchart is shown for a method of controlling the operation of the pairing and allocation device.

[0073] Figure 6 A flowchart illustrating a method for controlling the operation of a context-sensing control device is shown, and

[0074] Figure 7 A flowchart is shown for a method of controlling the operation of RF context sensing arrangement. Detailed Implementation

[0075] RF context sensing is a technique that allows for the reliable detection of predetermined contextual situations (such as movement, presence, or occupancy) based on how biological (especially human) influences or interferes with wireless signals transmitted between a group of RF sensing nodes (including transmitter nodes, receiver nodes, transceiver nodes, or any combination thereof) acting as RF sensing nodes. RF context sensing functionality ultimately relies on comparing currently determined RF signal metrics (such as Received Signal Strength Indicator (RSSI) values ​​or bit error rate values) or metrics based on information accessible via given Channel State Information (CSI) (e.g., line-of-sight components, channel gain, etc.) with a previously established baseline used as a reference. Typically, the performance of an RF context sensing setup depends on the accuracy of the established baseline. A baseline is defined for a corresponding transmitter-receiver pair of RF sensing nodes, where one node acts as a transmitter for RF presence sensing functionality, and the other RF sensing node acts as a receiver for that functionality. Thus, the baseline is associated with a given configuration of the RF sensing nodes and objects within a given sensing volume. In an exemplary case where the RF sensing nodes are in fixed positions, a baseline is established for an empty room (i.e., a room without furniture). If, at a later point in time, the current value of a predetermined RF signal metric deviates significantly from the baseline, this interference can be very definitively attributed to the movement or presence of an object in the room. However, if the baseline has already been established under “noisy” conditions—i.e., the presence of movable objects (such as, for example, chairs) in the room—it is, in principle, more difficult to distinguish between current values ​​of RF signal metrics that differ from the baseline, due to the different arrangement of objects within the sensing volume and due to the presence or movement of living organisms within the sensing volume. Therefore, ensuring a reliable transmitter-receiver pair and a corresponding baseline is crucial for the performance of an RF context sensing setup.

[0076] In the context of this invention, the term "sensing volume" refers to a predetermined space in which presence detection is to be performed, such as, for example, a room, a parking lot, or a section of street. The actual sensing volume in which presence can be detected depends on the location of the RF sensing nodes and their transmission directions, and in a first-order approximation is the sum of the individual sensing volumes associated with one or more transmitter-receiver pairs. In some cases, portions of the sensing volume are not covered by any sensing volume, and it is impossible to detect the contextual situation (such as the presence of a person in these portions of the sensing volume) using an RF context sensing arrangement.

[0077] It is important to note that the transmitter and receiver roles discussed in this article apply only to RF presence sensing functionality. RF sensing nodes (which are typically communication nodes in a wireless communication network) can dynamically change the roles of the transmitter and receiver used to perform communication functions. For example, once transmitter-receiver pairs and corresponding roles have been assigned, the RF sensing node can continue to perform the intended communication functions; however, only those RF signals provided by the RF sensing node with transmitter functionality and received by the RF sensing node with receiver functionality will be used for RF presence sensing.

[0078] Figure 1AA schematic illustration of a pairing assignment device 100 suitable for an RF context sensing arrangement is shown. The pairing assignment device 100 includes a sensing node location determination unit 102 configured to determine location information PI with respect to the respective locations of RF sensing nodes 104, 106 relative to a predefined sensing volume (room 108 in this particular case). The pairing assignment device 100 also includes a pairing assignment unit 110 connected to the sensing node location determination unit 102, and configured to: assign at least one transmitter-receiver pair among the various RF sensing nodes in the sensing arrangement to perform RF sensing functions using the determined location information PI; assign a transmitter role Tx and a receiver role Rx to the RF sensing nodes of a given transmitter-receiver pair, respectively; and provide pairing information indicating at least one assigned transmitter-receiver pair and the assigned transmitter and receiver roles. In this particular case, the pairing assignment unit assigns a transmitter role to RF sensing node 106 and a receiver role to RF sensing node 104 based on the determined location information PI and a predefined assignment algorithm. As a non-limiting example, the given allocation algorithm is configured to assign a transmitter role to RF sensing nodes located at or near the ceiling of a room and not to RF sensing nodes located near the floor, because these nodes may be more easily blocked by objects in room 108. This is due to the fact that although RF signals may pass through most objects, the relative attenuation they suffer is also a function of the distance between the transmitter of the RF signal and the interfering object. Therefore, an RF signal emitted from an RF sensing node placed close to an object may attenuate more than if the same object were placed further away, i.e., be received by another RF sensing node with higher attenuation. Therefore, according to the previous example, the predefined allocation algorithm is configured to assign transmitter and receiver roles to RF sensing nodes in a transmitter-receiver pair, taking into account the probability that an object is placed close to the RF sensing node. For example, a transmitter-receiver pair where the transmitter is an RF sensing node (preferably a lighting node) located at or near the ceiling may be less affected by changes in furniture position, as large objects are less likely to be placed under them, whereas in RF sensing nodes located on walls, objects (such as wardrobes, chairs, clothes racks, etc.) are more likely to be placed close to them.

[0079] For example, and according to an exemplary given predetermined allocation algorithm, if two RF sensing nodes are located at or near the ceiling, two transmitter-receiver pairs are allocated: wherein the first RF sensing node acts as an allocated transmitter role and the second RF sensing node is allocated a receiver role; and wherein the first RF sensing node acts as a second allocated receiver role and the second RF sensing node is allocated a transceiver role.

[0080] Optionally, as indicated by the dashed line, the pairing allocation device 100 may include an output unit 112 configured to provide an allocated pairing signal indicating pairing information. Figure 1A In a specific example, an assigned pairing signal is provided to the RF sensing nodes of the assigned transmitter-receiver pair. This is particularly advantageous for RF context sensing arrangements, where the RF sensing nodes are configured to: determine presence, i.e., include a context determination unit configured to determine the current value of a predetermined RF signal metric; and use the determined current value and a predetermined baseline to determine the presence of a living organism within the sensing volume associated with the transmitter-receiver pair. In this way, only those RF sensing nodes assigned as transmitter-receiver pairs will perform the RF context sensing function.

[0081] In an alternative example (not shown), assigned pairing signals are provided to the RF sensing arrangement control unit. This external RF sensing arrangement control unit is configured to store baselines for one or more transmitter-receiver pairs, receive current values ​​of predetermined RF signal metrics, and perform RF context sensing functions using only the values ​​associated with the transmitter-receiver pairs assigned by the pairing assignment device 100. In an alternative RF sensing arrangement, the RF sensing arrangement control unit receives detection signals from RF sensing nodes configured to determine the presence of living organisms, and, in order to perform the RF context sensing functions, uses only those detection signals associated with the assigned transmitter-receiver pairs, i.e., the detection signals provided by the RF sensing node acting as the receiver in response to RF signals received by the RF sensing node acting as the transmitter.

[0082] Additionally or alternatively, the pairing and allocation device 100 may also include an input unit 114 connected to the sensing node location determination unit and configured to receive location input data indicating location information. The location information may be generated, for example, during the network access initialization process, wherein a corresponding location-related tag is associated with the RF sensing node. In a particularly advantageous example, the network access initialization process requires input of specific location information suitable for allocating transmitter-receiver pairs according to a given allocation algorithm.

[0083] As indicated by the dashed lines, the pairing and allocation device 100 may optionally include an environmental information determination unit 116, which is configured to determine environmental information EI related to one or more objects present in the sensing volume 108. In this particular pairing and allocation device, the pairing and allocation unit is also connected to the environmental information determination unit and is configured to also use the determined environmental information to allocate at least one transmitter-receiver pair and transmitter and receiver roles. In this particular pairing and allocation device, environmental information is received via an input unit 118, which is configured to receive environmental input data indicating the environmental information EI. In the exemplary pairing and allocation device, the input unit 118 is a dedicated input unit, different from the input unit 114. However, in an alternative embodiment, a single input unit is configured to receive both environmental input data and location input data.

[0084] In a specific pairing and assignment device, environmental information is received from an external dedicated unit. This external dedicated unit may obtain the environmental information, for example, by analyzing panoramic images of a predefined sensing volume (e.g., a room). Alternatively, the external dedicated unit may include a 3D time-of-flight camera that enables the identification of objects in the room with or without further user input via an appropriate user interface, through which the user can assign predetermined tags to objects seen in the image, tags that are recognizable by the environmental information determination unit.

[0085] Additionally, in another exemplary pairing and allocation device, the environmental information determination unit is also configured to determine intended use information related to the intended use of the sensing volume. In this particular pairing and allocation device, the pairing and allocation unit is also configured to use the intended use information to allocate at least one transmitter-receiver pair and transmitter and receiver roles.

[0086] For example, typical actions performed within a predefined sensing volume (e.g., a given room) influence the assignment of transmitter-receiver pairs and the transmitter and receiver roles between those pairs. For instance, using an RF sensing node placed at chest height for RF context sensing would provide accurate detection. However, office spaces may contain numerous monitors, laptops, piles of files, desk lamps, etc., which can effectively block or negatively impact RF signals in ways detrimental to RF context sensing. However, people tend to spend most of their time sitting in office spaces. Therefore, assigning transmitter-receiver pairs to RF sensing nodes located closer to the floor could potentially generate richer or more significant data for RF presence sensing.

[0087] Figure 1BAn embodiment of an RF context sensing arrangement 150 is illustrated, including a pairing and allocation device 100 communicatively connected to a context sensing control device 152. The context sensing control device 152 includes a storage unit configured to store and provide to the pairing and allocation device location information PI relating to the respective positions of RF sensing nodes 104, 106 relative to a predefined sensing volume 108. For example, the stored and provided location information may include information indicating that the RF sensing nodes are located on the ceiling of room 108 and that the RF sensing nodes are located on a wall. Optionally, as indicated by the dashed lines, the context sensing control device 152 may also provide environmental information EI relating to one or more objects—such as chairs 107 and 109 and table 111 ultimately present in the sensing volume 108. The environmental information may also indicate the intended use of the sensing volume, such as indicating that room 108 is an office.

[0088] For an exemplary pairing and assignment device, environmental information may also include metadata about the room or objects within it, such as furniture. For example, metadata may indicate the material or shape of an object in a particular context. The presence of movable objects, such as chairs, with large metal frames suggests that RF sensing nodes located or likely to be near them may be less suitable for performing RF context sensing functions because they are more susceptible to the reflective surfaces of the metal frame. In other words, a movable chair containing metal may have a greater impact on RF context sensing functions than a chair made of plastic, fabric, or wood.

[0089] Similarly, the materials used for doors and windows, which can remain closed or open, can also be considered. In an exemplary RF context sensing arrangement, environmental information is provided by dedicated software, such as, but not limited to, LetsPlott home improvement software.

[0090] In another RF presence sensing arrangement, environmental information indicates a heatmap that highlights the frequency of a person's presence in different sampling areas of the room. The more sampling areas, the more accurate the heatmap. A pairing assignment device is advantageously configured to map the locations of RF sensing nodes onto the heatmap and assign at least two RF sensing nodes as transmitter-receiver pairs, said at least two RF sensing nodes having the minimum probability that someone is in front of them and thus blocks or attenuates the RF signal across the entire sensing volume. In an embodiment, the heatmap is determined by direct measurement. Alternatively, it is estimated by 3D time-of-flight scanning. For example, an RF sensing node located above a door is a good candidate for being assigned a transmitter role.

[0091] Based on location information and ultimately, also based on received environmental information, the pairing assignment unit assigns the transmitter role to RF sensing node 106 in a transmitter-receiver pair and the receiver role to RF sensing node 104. The pairing assignment device provides an assigned pairing signal indicating the assignment to the context sensing control device 152. The context sensing control device further includes a context determination unit 156 configured to receive pairing information and, as explained above, determine the presence of an object in the sensing volume 108 using the current value of a predetermined RF signal metric and a corresponding baseline stored in a baseline storage unit 153, which is configured to store one or more baseline values ​​associated with at least one transmitter-receiver pair. It is noteworthy that two different RF sensing nodes configured as transceivers generate two different transmitter-receiver pairs, depending on the assigned role (i.e., transmitter or receiver role).

[0092] Figure 2 A schematic block diagram of an embodiment of an RF context sensing arrangement 250 is shown, wherein the context sensing control device 252 includes a pairing assignment device 200. The current discussion will focus on... Figure 1B RF context sensing arrangement 150 and Figure 2 The RF context sensing arrangements 150 and 250 differ. The features common to both RF context sensing arrangements 150 and 250 will be referred to using the same reference numerals except for the first numeral, which is “1” for RF context sensing arrangement 150 and “2” for RF context sensing arrangement 250.

[0093] Location information, and in some specific embodiments, environmental information, is internally provided to the pairing allocation device 200, which in this case is implemented as a unit of the context sensing control device 252. Pairing information indicating the assigned transmitter-receiver pair is internally provided to the context determination unit 256, where the assigned transmitter-receiver pair in this specific example is an RF sensing node 206 acting as a transmitter and an RF sensing node 205 acting as a receiver. In this specific example, the context determination unit 256 is also configured to receive current RF signal metrics from the RF sensing nodes 204, 205, and 206 placed in the sensing volume, which may be affected by the presence of a person in the sensing volume. In this case, the predetermined RF signal metric is the current received signal strength indicator RSSI value. The RF sensing nodes 204, 205, and 206 are configured to wirelessly communicate with their respective neighboring nodes. The RF sensing nodes are configured to determine the RSSI value of a given RF signal provided by the neighboring nodes and provide that value to the context determination unit 256. For example, RF sensing node 204 provides a value RSSI indicating the signal strength of the RF signal provided by RF sensing node 205. 205 Correspondingly, RF sensing node 206 provides a value RSSI indicating the signal strength of the RF signal provided by RF sensing node 205. 205 This value is also received by node 206. RF sensing node 205 then provides the context determination unit 256 with the RSSI value, which indicates the signal strength of the RF signal provided by RF sensing node 204. 204 and the RSSI value indicating the signal strength of the RF signal provided by the RF sensing node 206. 206 .

[0094] The context determination unit also has access to the baselines stored in the baseline storage unit 253 corresponding to one or more pairs of RF sensing nodes. Specifically, since the received pairing information indicates that the RF sensing node 206 is a transmitter of the RF context sensing function and that the RF sensing node is a receiver of the RF context sensing function, the context determination unit uses the corresponding baselines to evaluate the RSSI. 206 The value is used to determine whether a person is present in the sensing volume.

[0095] Figure 3An alternative is shown, illustrating a schematic block diagram of another embodiment of the RF context sensing arrangement 350. Here, similarly, those features common to RF context sensing arrangements 150, 250, and 350 will be designated using the same reference numerals except for the first numeral, which is “1” for RF context sensing arrangement 150, “2” for RF context sensing arrangement 250, and “3” for RF context sensing arrangement 350. The RF context sensing function is performed in a slightly different manner in RF context sensing arrangement 350. Pairing assignment device 300—which is also integrated within the context sensing control device 352 in this case—is configured to provide an assigned pairing signal indicating pairing information to the RF sensing nodes via an output unit. Thus, RF sensing node 306 is aware of its role as a transmitter of the RF context sensing function. Correspondingly, RF sensing node 305 is also aware of its role as a receiver and RF sensing node 306 as a transmitter. When an RF signal provided by an RF sensing node 306 is received at an RF sensing node 305, the node determines the RSSI value of the received RF signal and provides it to a context determination unit 356. The context determination unit 356 then uses the value and the corresponding baseline stored in the baseline storage unit 353 to determine whether a person is present.

[0096] In an alternative RF context sensing arrangement (not shown), the RF sensing node itself is configured to determine the RSSI value of the received signal and use a stored baseline to determine a flag (e.g., a binary flag indicating that a predetermined detection condition has been met). The value of the corresponding flag is then provided to a context determination unit, which in turn determines, based on pairing information provided by a pairing assignment device, which will be used for the RF presence determination function.

[0097] Figure 4A schematic diagram of a room R with tables T and chairs C1-C4 having different configurations at different time points (i)-(iv) is shown. Room R has three RF sensing nodes N1, N2, and N3, and together with a context sensing control device 452, forms an RF context sensing arrangement (450). To improve the reliability of the results of the RF context sensing function, several baselines are determined and stored for each possible transmitter-receiver pair during the network access initialization phase. Each baseline is determined at different time points (i)-(iv) and is associated with a corresponding different location of one or more objects present in the sensing volume. In this particular example, and for each of the four different time points, after the network access initialization phase, the baseline storage unit includes the baselines of pairs N1-N2, N2-N1, N2-N3, N3-N2, N1-N3, and N3-N1, wherein, in the case of the pairing allocation device assigning the corresponding transmitter-receiver pair, in each pair, the node named first will be the transmitter node, and the node named second will be the receiver node. This means that each pair has four associated baselines, each of which is used for Figure 4 This diagram shows each of the four spatial configurations of objects within room R. The different positions of multiple pieces of furniture will affect the baseline determined in each case.

[0098] The presence sensing control device's detection determination unit is advantageously configured—when performing RF context sensing—to determine multiple detection events using a signal quality value and a corresponding one of multiple stored baseline values ​​associated with the transmitter-receiver pair. The detection events are then compared to a predetermined weighting factor, which is a function of the probability of each of scenarios (i)-(iv) occurring during the expected use of room R. The context sensing control device 452 then uses the multiple determined detection events to determine whether a predetermined contextual situation has occurred or is currently occurring, such as the presence of an object in the sensing volume. For example, some RF sensing node pairs and corresponding baselines can be used as backups so that the RF presence sensing function can be supplemented to confirm or reject the detection hypothesis when in doubt.

[0099] Figure 5A flowchart of a method for controlling the operation of a pairing assignment device is shown. The method includes determining, in step 502, location information PI relating to the corresponding position of an external RF sensing node relative to a predefined sensing volume of an RF context sensing arrangement. Method 500 further includes: in step 504, using the determined location information, assigning at least one transmitter-receiver pair among the respective RF sensing nodes of the RF context sensing arrangement to perform RF context sensing functions, and assigning a transmitter role and a receiver role (Rx) to the RF sensing nodes of a given transmitter-receiver pair, respectively; and in step 506, providing (506) pairing information indicating at least one assigned transmitter-receiver pair and the assigned transmitter and receiver roles.

[0100] A particular method for controlling the operation of the pairing and allocation device further includes, in step 503, determining environmental information relating to one or more objects present in the sensing volume. Step 503 is optional and therefore is represented by a box with a break line. In this particular method, step 504 involves also using the determined environmental information to allocate at least one transmitter-receiver pair and transmitter and receiver roles.

[0101] Figure 6 A flowchart is shown for a method of controlling the operation of a context-sensing control device. The method includes performing... Figure 5 The method 500 includes the following steps: in step 602, storing a baseline associated with at least one transmitter-receiver pair to perform an RF context sensing function; in step 604, determining a signal quality value indicating a predetermined RF signal metric, the RF signal being received by the RF sensing node having a receiver role and transmitted by the RF sensing node having a transmitter role, the RF signal metric being susceptible to the presence of a living organism in the sensing volume; and in step 606, using the determined signal quality value and the corresponding baseline, determining whether a predetermined context has already occurred in the sensing volume.

[0102] Figure 7 A flowchart is shown for a method of controlling the operation of an RF context sensing arrangement. The method includes performing... Figure 5 Method 500. The method further includes determining and providing a signal quality value in step 702, the signal quality value indicating a predetermined RF signal metric of at least one RF signal received by an RF sensing node of a transmitter-receiver pair having receiver functionality and provided by an RF sensing node of a transmitter-receiver pair having transmitter functionality. The method also includes performing the above-referenced... Figure 6 Steps 602, 604, and 606 are described.

[0103] In summary, the present invention relates to a pairing and allocation device, comprising: a sensing node location determination unit configured to determine location information relating to a corresponding position of an external RF sensing node relative to a predefined sensing volume of an RF context sensing arrangement; and a pairing and allocation unit configured to use the determined location information to allocate at least one transmitter-receiver pair among the respective RF sensing nodes of the RF context sensing arrangement to perform RF context sensing functions, assigning a transmitter role and a receiver role to the RF sensing nodes of a given transmitter-receiver pair, respectively. The pairing and allocation device then provides pairing information indicating at least one allocated transmitter-receiver pair and the allocated transmitter and receiver roles, thereby enabling an increased tolerance of the RF context sensing arrangement to positional changes of movable objects.

[0104] By studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement other variations of the disclosed embodiments in practicing the claimed invention.

[0105] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0106] A single unit or device can perform the functions of several items listed in the claims. The mere fact that a particular measure is referenced in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously.

[0107] Computer programs can be stored / distributed on suitable media, such as optical storage media or solid-state media, supplied together with or as part of other hardware; but they can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

[0108] Any reference numerals in the claims should not be construed as limiting the scope.

Claims

1. A context-sensing control device (252), comprising: A pairing and distribution device (100), the pairing and distribution device (100) comprising: - The sensing node location determination unit (102) is configured to determine location information related to the corresponding position of the external RF sensing node relative to a predefined sensing volume (108) of the RF context sensing arrangement (150); and - Pairing allocation unit (110), connected to the sensing node position determination unit, and configured to: - Using the determined location information, assign at least one transmitter-receiver pair among the various RF sensing nodes in the RF context sensing deployment to perform RF context sensing functions; - Assign transmitter and receiver roles to the RF sensing nodes of a given transmitter-receiver pair, respectively; and - Provides pairing information indicating at least one assigned transmitter-receiver pair and the assigned transmitter and receiver roles; and The pairing and distributing device (100) further includes: - An environmental information determination unit (116) is configured to determine environmental information relating to one or more objects present in the sensing volume; and The pairing allocation unit (110) is also connected to the environmental information determination unit (116) and is configured to further use the determined environmental information to allocate the at least one transmitter-receiver pair and transmitter and receiver roles; wherein the environmental information indicates the material used to manufacture the one or more objects and the confidence level of the probability that the one or more objects are moved or stationary; and The context sensing control device (252) also includes: The baseline storage unit (253) is configured to store the baseline associated therewith for the at least one transmitter-receiver pair; - Context determination unit (256), connected to the baseline storage unit and the pairing allocation device, is configured to determine a signal quality value of a predetermined RF signal metric indicating an RF signal received by the RF sensing node having a receiver role and transmitted by the RF sensing node having a transmitter role, the RF signal metric being affected by the presence of a living organism in the sensing volume, and the context determination unit (256) is further configured to use the determined signal quality value and the corresponding baseline to determine whether a predetermined context has occurred in the sensing volume.

2. The context sensing control device (252) according to claim 1 further includes an output unit (112) configured to provide an assigned pairing signal indicating the pairing information.

3. The context sensing control device (252) according to claim 1 further includes an input unit connected to the sensing node position determination unit and configured to receive position input data indicating the position information.

4. The context sensing control device (252) according to claim 1, wherein: - The environmental information determination unit is further configured to determine intended use information indicating the intended use of the sensing volume; and The pairing allocation unit is also configured to use the intended use information to allocate the at least one transmitter-receiver pair and transmitter and receiver roles.

5. The context sensing control device (252) according to claim 1 further includes an input unit connected to the environment information determination unit and configured to receive environmental input data indicating the environment information.

6. The context sensing control device (252) according to claim 1, wherein: - The baseline storage unit is also configured to store multiple baselines that are determined at different times and associated with corresponding different locations of one or more objects present in the sensing volume and with corresponding transmitter-receiver pairs; and -The context sensing control device (252) further includes a detection determination unit configured to determine a plurality of detection events using the signal quality value and a corresponding one of a plurality of stored baselines associated with the transmitter-receiver pair, and to determine whether a predetermined contextual situation has occurred in the sensing volume using the plurality of determined detection events.

7. An RF context sensing device, comprising: - At least two RF sensing nodes are configured to transmit and receive RF signals and determine and provide signal quality values, which indicate a predetermined RF signal metric of the RF signals received by the respective RF sensing nodes; and - The context sensing control device according to claim 1.

8. A method (500) for operating a context-sensing control device, the method comprising: - Determine location information related to the corresponding position of the external RF sensing node relative to the predefined sensing volume (108) of the RF context sensing arrangement (150); - Using the determined location information, allocate at least one transmitter-receiver pair among the RF sensing nodes in the RF context sensing arrangement to perform RF context sensing functions, and assign transmitter and receiver roles to the RF sensing nodes of a given transmitter-receiver pair, respectively. as well as - Provides pairing information indicating at least one assigned transmitter-receiver pair and the assigned transmitter and receiver roles; The method further includes: - Determine environmental information relating to one or more objects present in the sensing volume; and - It also uses the determined environmental information to assign at least one transmitter-receiver pair and transmitter and receiver roles; The environmental information indicates the material used to manufacture the one or more objects and the confidence level of the possibility that the one or more objects are moved or stationary; - For at least one transmitter-receiver pair, store the baseline associated with it; - Determine a signal quality value for a predetermined RF signal metric indicating an RF signal received by the RF sensing node acting as a receiver and transmitted by the RF sensing node acting as a transmitter, the RF signal metric being susceptible to the presence of organisms in the sensing volume; and - Use the determined signal quality value and the corresponding baseline to determine whether the predetermined context has already appeared in the sensing volume.

9. A method (700) for operating an RF context sensing arrangement, the method comprising: - Perform the method according to claim 8; - Determine and provide a signal quality value, the signal quality value indicating a predetermined RF signal metric for at least one RF signal, the at least one RF signal being received by an RF sensing node of a transmitter-receiver pair with receiver functionality and provided by an RF sensing node of a transmitter-receiver pair with transmitter functionality; - For the at least one transmitter-receiver pair, store the associated baseline; - Determine a signal quality value for a predetermined RF signal metric that indicates an RF signal received by the RF sensing node having a receiver role and transmitted by the RF sensing node having a transmitter role, the RF signal metric being susceptible to the presence of organisms in the sensing volume; as well as - Use the determined signal quality value and the corresponding baseline to determine whether the predetermined context has already appeared in the sensing volume.

10. A computer program product comprising instructions that, when executed by a computer, cause the computer to perform the method of claim 8.

Images