Radio frequency based sensing for dense node deployments

Abstract

The invention relates to performing RF-based sensing in an RF system (100) comprising a plurality of nodes (10, 27, 28, 29, 30), at least two nodes (10) of the plurality of nodes comprising a dense node arrangement (26). A first group of nodes is formed comprising at least one node (10) of the dense node arrangement (26) and a second group of nodes comprising at least one node of the first group and at least one additional node of the dense node arrangement. RF-based sensing is performed by the first group in a first sensing area for detecting a first sensing event indicative of a presence of an object (32) in the first sensing area. If the first sensing event is detected, RF-based sensing is performed by the second group in a second sensing area (60) at least partially overlapping the first sensing area for identifying a second sensing event indicative of an object activity.

Description

Technical Field

[0001] The present invention relates to a radio frequency (RF) system having multiple nodes, an RF supersystem having two or more RF systems, a method for performing RF-based sensing in an RF system having multiple nodes, and a computer program product. Background Technology

[0002] US 2019 / 0384409 A1 discloses a system comprising a wireless communication device operable to transmit wireless signals through space, a network-connected device associated with the space, and a computer device including one or more processors. The computer device is operable to perform operations including: obtaining channel information based on wireless signals transmitted through the space by the one or more wireless communication devices via an operation of a gesture recognition engine; analyzing the channel information to detect gestures in the space; identifying an action to be initiated in response to the detected gesture; and sending an instruction to the network-connected device associated with the space to perform the action. Detecting the gesture includes using a time-frequency filter to detect the time-frequency characteristics of the gesture.

[0003] WO 2020 / 043592 A1 discloses a system for selecting one or more devices in a wireless network to transmit, receive, and / or process RF signals for presence and / or location detection. The system includes at least one processor configured to determine the suitability of each of a plurality of devices for transmitting, receiving, and / or processing RF signals for presence and / or location detection, select a subset of devices from the plurality of devices based on the suitability determined for each of the plurality of devices, and instruct at least one device in the subset of devices to act as a device for transmitting, receiving, and / or processing RF signals for presence and / or location detection.

[0004] WO 2020 / 037399 A1 discloses a method for mapping the boundaries of a given environment using a processor of a computer system. The method includes: determining the trajectory of a body within the given environment over a given time period; and determining one or more of an outer boundary and an inner boundary of the given environment based on the body's trajectory. The method also includes determining a movement pattern of the body within the given environment over the given time period; and determining the functional identity of at least one region within the given environment based on the body's movement pattern to obtain the mapped given environment. Summary of the Invention

[0005] One object of the present invention can be considered as providing an RF system, an RF supersystem, a method for performing RF-based sensing in an RF system, a computer program product for performing RF-based sensing in an RF system, and a computer-readable medium that allows for improved performance of RF-based sensing for identifying object activity.

[0006] In a first aspect of the invention, an RF system is proposed comprising a plurality of nodes for performing RF-based sensing. At least two of the plurality of nodes are included in a dense node arrangement. The RF system is configured to: form a first set of nodes including at least one node in the dense node arrangement; form a second set of nodes including at least one node in the first set and at least one additional node in the dense node arrangement; perform RF-based sensing by the first set in a first sensing region for detecting a first sensing event indicating the presence of an object in the first sensing region; and if the first sensing event is detected, perform RF-based sensing by the second set in a second sensing region that at least partially overlaps with the first sensing region to identify a second sensing event indicating object activity.

[0007] Because the RF system initially performs RF-based sensing by a first group to detect the presence of an object in a first sensing area, and then, if the presence of an object is detected, a second group performs RF-based sensing in a second sensing area that at least partially overlaps with the first sensing area to identify the object's activity, the radio interference and cost associated with identifying activity can be reduced. This allows for the initial use of a first group with lower bandwidth, followed by the use of a second group with higher bandwidth. The use of a large number of densely arranged nodes allows for the identification of object activity, as activity identification requires a large number of nodes that are closer to each other. The use of at least one densely arranged node (e.g., only one or a few nodes) allows for reduced radio interference to other functions of the nodes (e.g., data exchange), because less radio signal is emitted when the first group performs RF-based sensing compared to when the second group performs the RF-based sensing.

[0008] These nodes can be configured to perform functions, such as providing lighting, heating, cooling, or any other function besides performing RF-based sensing. One or more of the nodes can be illuminators or lamps.

[0009] A sensing area corresponds to a specific volume or space in which RF-based sensing is performed. A first sensing area may be defined by a first set. A second sensing area may be defined by a second set. For example, the locations of a set of nodes can define a corresponding sensing area, such that the corresponding sensing area is formed between the locations of that set of nodes. The first and second sensing areas at least partially overlap because the second set includes the nodes of the first sensing area and at least one additional node in a dense node arrangement. The second sensing area may be smaller than the first sensing area; for example, the second sensing area may be part of the first sensing area in which the object is located. The sensing area may also be predefined. For example, the first and second sensing areas may be the same, for example, corresponding to a specific volume, such as a room or floor in a building.

[0010] The first sensing event can indicate the presence of one or more objects. Objects can be, for example, people, robots, animals, or any other type of object that can be detected by RF-based sensing. The second sensing event can also indicate one or more activities of one or more objects. Activities can include, for example, posture, cooking, jumping, falling, breathing, or any other activity of the object.

[0011] The presence of a detected object should be understood as the object being present in the first sensing area. The activity of the detected object will be understood as what the detected object is doing in the second sensing area. For example, when an object (e.g., a user such as a person) jumps into the first sensing area, the first group can initially detect the user's presence in the first sensing area, and subsequently the second group (i.e., with a higher number of nodes) can be used to identify the user's activity, i.e., jumping.

[0012] Dense node arrangement refers to a node arrangement where the distance between nodes allows for higher resolution RF-based sensing, sufficient to perform object activity recognition. A dense node arrangement can be, for example, a multi-node device, which can take the form of multiple light sources, such as a chandelier comprising a certain number of nodes and / or a densely packed set of nodes, for example, in the form of a downlight, e.g., in a kitchen. A dense node arrangement can have a node density with a lower limit as a threshold and / or a distance between nodes with an upper limit as a threshold; for example, nodes in a dense node arrangement are tightly packed and the distance between nodes is small. For example, the lower limit of the node density threshold could be at least 5 nodes per square meter and / or the maximum distance between nodes could be less than 20 cm. A dense node arrangement can have a node density of, for example, at least 5 nodes per square meter (e.g., at least 10 nodes per square meter). For example, the distance between nodes could be between 10 cm and 30 cm. Higher node density allows for better resolution to perform RF-based sensing. RF-based sensing performed by an RF system utilizing a higher node density can, due to its higher resolution, allow for the recognition of, for example, the movement of different fingers. Conversely, if RF-based sensing is performed by an RF system utilizing a lower node density, arm movement can be identified, but the RF system may not be able to distinguish finger movement due to its lower resolution.

[0013] RF-based sensing allows for the detection of the presence of objects in a first sensing area and the identification of various activities of objects in a second sensing area. Sensing algorithms can detect and analyze how objects within the respective sensing areas affect RF signals. RF signals are used, for example, to transmit RF messages between node pairs. RF-based sensing can be used as a means of detecting and classifying object activity in open spaces or buildings (such as homes, offices, etc.). For example, based on Zigbee messages transmitted and received by nodes in the form of smart lights, RF-based sensing can determine the presence of objects, for example, in the form of user gestures in a room to automatically turn on lights and user gestures to activate specific lighting scenes. For example, a node in the form of a WiFi router can identify a user's breathing rate, etc.

[0014] Analysis of RF signals can be performed at the appropriate nodes or in the central control unit of the RF system, for example, for presence detection or activity identification. A reference list (e.g., a lookup table) including the identified activities can be stored in the nodes or control unit. The reference list can be compared with the current activity of the object to identify the current activity. Alternatively, machine learning (ML) or artificial intelligence (AI) based algorithms can be used to identify the activity of the object, such as a user's gesture, which are trained to extract features from the harassed RF messages.

[0015] The fundamental principle of RF-based sensing is that interference in the RF signals within each sensing area is a function of both the physical elements (e.g., moving objects) and the frequency of the RF signals. For example, the location and number of objects, their weight, size, direction of movement, and other object properties can affect the RF signals. Therefore, interference caused by small objects (e.g., small users such as children) is different from interference caused by larger objects (e.g., larger users such as adults). This allows not only the detection of the presence of objects but also the detection of the type of object present, such as a child or an adult. Furthermore, interference caused by a single object differs from interference caused by multiple objects.

[0016] When RF-based sensing jumps between a range of very different frequency bands (e.g., from 2.4 GHz WiFi to 5 GHz WiFi, and then to 60 GHz used by the upcoming WiFi 6 standard), this can produce significantly different passive sensing results. However, channels within the same frequency band (e.g., 2.4 GHz WiFi channel 1 at 2412 MHz and WiFi channel 13 at 2472 MHz) can also affect RF-based sensing results.

[0017] An RF system can be configured to perform RF-based sensing by a second group based on a first sensing event (e.g., depending on the detection result, such as detecting the presence of a small user, a large user, a single user, or a group of users). For example, if the activity indicated by the second sensing event is breathing, children typically have a higher respiratory rate than adults and may require higher resolution. In this case, the message frequency used to transmit RF messages and / or the frequency of the RF signals used by the second group to perform RF-based sensing can be increased to provide higher resolution. The message frequency defines how many RF messages are transmitted per time interval, e.g., how many RF messages are transmitted per second. A higher message frequency allows for higher resolution. The frequency of the RF signals defines the frequency of the wave used to transmit the RF messages.

[0018] RF-based sensing can be performed, for example, by a group comprising at least two nodes, by transmitting RF signals from one node to another (i.e., between nodes in a pair) and analyzing the received RF signals. If the RF signals interact with one or more objects along their paths between the nodes, the RF signals are interfered with, for example, by being scattered, absorbed, reflected, or any combination thereof. These interferences can be analyzed and used to perform RF-based sensing in order to detect the presence of one or more objects.

[0019] If a group comprises only one node, that node can perform RF-based sensing by transmitting RF signals to a corresponding sensing area (e.g., a specific volume) associated with the group, receiving reflected RF signals from the specific volume, and analyzing the reflected RF signals. For example, one antenna in a node's antenna array can transmit RF signals, and another antenna in the same node's antenna array can receive reflected RF signals, allowing analysis of the reflected RF signals within the same node that transmitted the RF signals. RF-based sensing can also be performed in this manner by multiple nodes in an RF system.

[0020] Alternatively or additionally, in a group comprising at least two nodes, one node can transmit RF signals to a corresponding sensing area (e.g., a specific volume) associated with the group, and the reflected RF signals can be received and analyzed by another node in the group to perform RF-based sensing.

[0021] Interferenced and / or reflected RF signals can comprise RF-based sensing fingerprints based on RF signal parameters, such as the real and imaginary parts of permittivity and magnetic susceptibility. Different communication technologies have different absorption and reflection characteristics, resulting in different RF-based sensing fingerprints.

[0022] The first group can be optimized for performing presence detection. The RF system can be configured to perform RF-based sensing in a first sensing area by the first group, so as to detect a first sensing event indicating the presence of an object in the first sensing area based on a first setting of RF-based sensing parameters (e.g., including a first message frequency, such as 30 Hz, between 10 Hz and 300 Hz). The first group may consist of just one node from a dense node arrangement. Additionally, the first group may include other nodes from a plurality of nodes in the RF system. Performing RF-based sensing at a lower message frequency allows for reduced wireless interference.

[0023] The second group can be optimized for performing activity recognition, such as gesture recognition. The RF system can be configured to perform RF-based sensing in a second sensing area by the second group, so as to identify second sensing events indicating activity of objects in the second sensing area based on a second setting of RF-based sensing parameters (e.g., including a second message frequency, such as 1000 Hz, between 300 Hz and 5000 Hz). Performing RF-based sensing at a higher message frequency allows for higher resolution.

[0024] RF systems can be configured for calibration, including groups of RF systems. RF system calibration can allow for improvements in RF-based sensing because it can determine the optimal number, physical location, and configuration of nodes, for example, to perform presence detection and activity recognition, as well as proximity detection.

[0025] Calibration can include arranging nodes, such as placing nodes at certain physical locations, forming groups by including nodes in corresponding groups, and / or defining sensing areas (e.g., including a first sensing area and a second sensing area). Placing nodes at certain physical locations can include arranging nodes at specific distances from each other. The second sensing area can be defined as a context-aware area, i.e., a specific activity is expected to be performed in the second sensing area; for example, if the activity is cooking, the sensing area is defined as the kitchen. The first sensing area can also be defined as a context-aware area. Defining sensing areas can allow for pre-definition of sensing areas and reduce or avoid false positives, such as detecting the presence of objects in adjacent rooms. Detecting false positives can increase costs, for example, when there are no objects in the room and it is unlikely that the second group will perform activity identification. Furthermore, actions performed in response to the detection of the presence of an object may be performed incorrectly, such as activating lighting in the room.

[0026] The calibration of an RF system can be performed on an object-dependent basis. For example, different objects (such as users) may be subjected to different latency or perform different activities, such as cooking, training, or playing games. This allows the RF system to be optimized to perform RF-based sensing for the sensing applications typically required by users of RF systems.

[0027] The RF system can be configured to optimize RF-based sensing based on user feedback. The RF system can be configured, for example, to require the user to perform activities at different locations when forming a second group, to calibrate the RF-based sensing parameters used to perform the RF-based sensing, including message frequency and recognition algorithm.

[0028] An RF system can be configured to form a first group of nodes, such that the first group includes at least one node in a dense node arrangement and at least one node not included in the dense node arrangement. The corresponding two nodes (one of the at least one node in the dense node arrangement and one of the at least one node not included in the dense node arrangement) can form a node pair. The node pair can perform RF-based sensing by exchanging RF signals between the two nodes in the node pair. This can improve the performance of RF-based sensing because the node not included in the dense node arrangement has a greater distance from at least one node in the dense node arrangement, and this can increase the size of the first sensing area if RF messages are transmitted between the node pair containing the node not included in the dense node arrangement and the node included in the dense node arrangement.

[0029] The RF system can be configured to perform RF-based sensing by a second group in a second sensing area to identify a second sensing event when a first sensing event is detected.

[0030] The RF system can also be configured to perform RF-based sensing by a second group in a second sensing area to identify a second sensing event if additional conditions are met. One such additional condition could be, for example, that the object is near a dense node arrangement.

[0031] Upon detection of a first sensing event, the RF system can be configured to perform RF-based sensing in a third sensing region by at least one node of a first group to detect a third sensing event indicating the location of an object near a dense node arrangement. The third sensing region may at least partially overlap with the first and second sensing regions. The RF system can be configured to perform RF-based sensing at the location of the object by a second group upon detection of both the first and third sensing events to identify a second sensing event.

[0032] This allows for a reduction in the number of nodes used by the RF system over time. Proximity detection and activity recognition typically require higher resolution and therefore higher density RF signals, provided by a greater number of nodes and / or higher message frequencies. Higher RF signal density increases resolution but also increases wireless interference. Performing RF-based sensing to detect a third sensing event indicating the location of an object in the vicinity of a dense node array in a cascade—that is, after the object's presence has been detected in the first sensing area—allows for reduced wireless interference. Furthermore, costs can be reduced because fewer nodes can be used to perform RF-based sensing to detect the object's presence. In summary, the RF system allows for a reduction in the number of nodes needed to perform RF-based sensing to detect the proximity of an object to a dense node array and the duration of object activity recognition, because the first set can use very few nodes to perform RF-based sensing to continuously detect the object's presence until it is detected. Only after presence is detected is a larger number of nodes needed to improve the resolution of the RF-based sensing.

[0033] The third sensing event can indicate that an object's location is close to the dense node arrangement, i.e., the object is near the dense node arrangement. For example, if the object's location is within a specific distance to, for example, the outer surface or center of the dense node arrangement, the object's location can be detected as being near the dense node arrangement. The object's location near the dense node arrangement can be, for example, a location corresponding to a physical location, such as a coordinate location, such as the object's location in the xy plane, or a relative location of the object with respect to the dense node arrangement, such as the object's location relative to the center of the dense node arrangement in the north, east, south, or west direction.

[0034] To determine the position of an object in the xy-plane, triangulation can be performed using at least three nodes. For example, if the first group includes at least three nodes, these nodes can be used; otherwise, additional nodes, such as those in a second group, can be used. The RF system can also be configured to form a third group of nodes, including at least one node from the first group and additional nodes, such as those from the second group. For example, if the first sensing area is asymmetrical relative to the dense node arrangement, two nodes can be used to determine the relative position of the object with respect to the dense node arrangement. For example, if beamforming and / or directional antenna arrays are used, the wireless transmission of the RF system can be directional, and the relative position of the object with respect to the dense node arrangement can be determined. For example, if WiFi is used as a communication protocol to perform RF-based sensing, WiFi channel state information (CSI) data describing wireless multipath characteristics can be used to determine the distance from the object to the dense node arrangement, i.e., whether the object is close to the dense node arrangement.

[0035] The third sensing area can be predefined or defined by a node performing RF-based sensing to detect a third sensing event. The third sensing area can be the same as the first and second sensing areas.

[0036] Optionally, in addition to the nodes in the first group, one or more nodes in the second group, not included in the first group, can perform RF-based sensing to detect a third sensing event. This can allow for improved resolution when performing proximity detection.

[0037] The detection of a third sensing event can also be used as a trigger for nodes near the location of a controlled object. For example, if the object is near a node, the node is activated, or a control mode that allows the corresponding node to be controlled via physical control, app, or voice commands is activated. These nodes can be activated to be included in a second group and used to perform RF-based sensing in a second sensing area.

[0038] RF systems can be configured to orchestrate RF messages transmitted for performing RF-based sensing and other data exchanges, such as RF data messages for lighting control, in order to reduce or avoid wireless interference. For example, RF messages, such as RF sensing messages, can be transmitted in different time intervals and / or on different channels than RF data messages. This allows for the reduction or avoidance of wireless interference.

[0039] The RF system can be configured to form a second group based on the object's location upon detection of a third sensing event. This allows for improved RF-based sensing because the selection of nodes included in the second group can be optimized so that the second sensing area is optimally covered by nodes used to identify the object's activity.

[0040] The RF system can be configured to adapt the message frequencies of one or more nodes (e.g., all nodes) in a second group for RF-based sensing performed by the second group. Node pairs that exchange RF messages for performing RF-based sensing closer to the object location can perform RF-based sensing at a lower message frequency compared to node pairs that exchange RF messages for performing RF-based sensing closer to the object location. The message frequency can be, for example, between 300 and 1000 messages per second, depending on the object's location relative to the corresponding node or node pair.

[0041] The RF system can be configured to form a first group by selecting nodes to be included in the first group based on one or more RF system parameters and / or activities to be identified by the second group. Alternatively or additionally, the RF system can be configured to form a second group by selecting at least one additional node in a dense node arrangement to be included in the second group, in addition to the nodes of the first group, based on one or more RF system parameters and / or activities to be identified by the second group. RF system parameters may include, for example, distances between nodes, corresponding locations of nodes, or any other RF system parameters. Additional nodes may be selectively added to the first group to form the second group in order to optimize the coverage of the second sensing area.

[0042] An RF system can be configured to adjust the message frequency used for transmitting RF messages by its nodes, thereby performing RF-based sensing based on which sensing event the node wants to detect or identify. Additionally or alternatively, the RF system can be configured to adjust the directionality of RF message transmission based on which sensing event the node wants to detect or identify.

[0043] The RF system can be configured, for example, to adjust the message frequency of one or more nodes in the second group when a third sensing event is detected, so that the activity of the object can be identified.

[0044] The RF system can also be configured to adjust the transmission power of the RF system based on the distance between the second set of nodes and objects.

[0045] Alternatively or additionally, the RF system can be configured to adjust the transmission frequency used to perform RF-based sensing, for example, from 2.4 GHz to 5 GHz WiFi. This can allow for improved RF-based sensing because, for example, 5 GHz WiFi is better suited for certain sensing applications (such as breathing rate recognition) because 5 GHz WiFi signals are more spatially confined than 2.4 GHz WiFi signals, which are prone to leakage and thus increase the risk of picking up other nearby movement.

[0046] The RF system can be configured to stop performing RF-based sensing to detect any other sensing events in the second sensing area when the second group performs RF-based sensing in the second sensing area to identify the second sensing event.

[0047] The RF system can stop performing RF-based sensing to detect any other sensing events in a second sensing area, or even in the first and third sensing areas. The RF system can be configured to stop RF-based sensing performed by the first group to detect a first sensing event and / or a third sensing event when RF-based sensing is performed by nodes in the second group to identify a second sensing event. In other words, the RF system can be configured to disable presence detection and / or proximity detection when the second group performs RF-based sensing to identify object activity. This allows for reduced wireless interference and optimized RF-based sensing because presence and proximity detection are not required when identifying object activity.

[0048] The RF system can be configured to have a second group perform RF-based sensing in a second sensing area to identify a second sensing event until a stop condition is met. The stop condition can include one or more of the following: identification of a second event, detection of a stop event, a predetermined duration having elapsed since the second group began RF-based sensing in the second sensing area to identify the second sensing event, and identification of inactivity of an object. This allows it to ensure that the second group, and therefore a larger number of nodes, only temporarily performs RF-based sensing.

[0049] A stop event is an event that causes the second set of RF-based sensing to cease performing the activity detection for an object. When activity is detected, a timer can be reset to a predetermined duration and begin counting down. If the timer reaches zero, inactivity of the object can be detected. A stop event could be, for example, if the object moves out of the second sensing area. For example, a stop event can be combined with a stop condition that identifies inactivity of the object. For example, if multiple activities are expected, such as an elderly person with dementia returning to the toilet twice immediately after waking up because they immediately forget their previous activities, this can allow ensuring that the second set of RF-based sensing performs the activity detection if additional activities are expected. For example, for a second sensing event in the form of respiratory rate recognition during sleep monitoring, a stop event could be, for example, the user waking up. This allows the determination of the user's respiratory rate to stop as long as it is no longer needed when the user wakes up and sleep monitoring ends.

[0050] The predetermined duration and stop event can depend on the activity indicated by the second sensing event. This allows the duration and stop event to be customized based on the expected end of the user's activity. The RF system can be configured to perform sleep stage monitoring of the user, for example, by performing RF-based sensing (e.g., WiFi RF-based sensing) based on recognizing the user's breathing rate. For example, the user waking up when the second event indicates a specific change in the user's breathing rate can be a stop event. Changing the breathing rate during the user's sleep can also be used to monitor the user's sleep. This allows for differentiation between REM sleep, non-REM sleep, and the user being awake. The RF system can be configured to detect a stop event, for example, recognizing that the user has transitioned from a sleep state to a wakeful state. Upon detecting a stop event, the RF system can stop the sleep stage monitoring performed by the second set of RF-based sensing based on the breathing rate.

[0051] The RF system can be configured to perform RF-based sensing for detecting a first or third sensing event when the second group stops performing RF-based sensing for detecting a second sensing event. In other words, when activity identification performed by the RF system is deactivated, the RF system can resume presence or proximity detection. This allows ensuring the use of the minimum number of nodes required for the current sensing application, thereby reducing wireless interference and cost.

[0052] The RF system can be configured to perform actions based on a detected first sensing event, a detected third sensing event, an identified second sensing event, and / or contextual information. The primary function of the RF system or at least one node of the first group can be, for example, performing actions based on presence detection in the form of automatically activating one or more functions of the RF system, such as providing security or turning lighting on and off. The RF system can be configured to perform functions upon detection of the first or third sensing event and upon identification of the second sensing event, such as activating or deactivating a node's function or adjusting the node's operating parameters, for example, in the form of a lighting fixture, such as dimming a light if cooking is detected as activity.

[0053] RF systems can be configured to perform more complex controls by combining identified activity with contextual information obtained from external devices. For example, an alarm can be activated if a user's smartphone GPS indicates that the user is not near the RF system, and the presence of a human-shaped object is detected by the opening of the first group or main door.

[0054] The second group can be configured to perform RF-based sensing via unicast RF messages. Unicast can be performed between one or more nodes in a dense node deployment and one or more nodes not included in the dense node deployment.

[0055] The second set of nodes may include directional antennas. This allows beamforming to be used to narrow the second sensing area.

[0056] The RF system can be configured to use different channels and therefore different frequencies to perform RF-based sensing by a second group to identify second sensing events, for example, switching from 2.4 GHz to 5 GHz or 60 GHz.

[0057] RF systems can be calibrated to perform RF-based sensing to detect sensing events and identify the activity of individual objects, such as users.

[0058] In another aspect of the invention, the RF super system includes two or more RF systems according to at least one of claims 1 to 9 or any embodiment of an RF system, such that the RF super system includes two or more densely arranged nodes at different locations.

[0059] The RF super system can be configured to form several first and second groups to identify second sensing events in various sensing areas within the RF super system. Different locations can be in the same room, on the same floor, or on different floors. The RF super system can also perform RF-based sensing between floors, such as inter-floor sensing, where a illuminator on the ceiling below an object (e.g., in a room on a lower floor) performs RF-based sensing of objects above it.

[0060] The RF super system can perform, for example, health monitoring or sleep monitoring for two users in a double bed. Health monitoring and sleep monitoring can include or be performed by respiratory rate recognition. In this case, for example, two dense node arrangements can be arranged in the same room on different sides of the double bed, such that each dense node arrangement can perform respiratory rate recognition during one user's sleep monitoring. The dense node arrangement can include, for example, several LED strips around the double bed, multi-lamp ceiling lights above the double bed, lights on various side tables on the sides of the double bed, reading lights mounted at the head of the double bed, etc. The dense node arrangement can also include non-lighting devices. The dense node arrangement of the RF super system can allow the detection of minute movements of the user's chest to identify the respiratory rate. Because the RF supersystem allows for the formation of a second set of RF-based sensing for performing RF-based sensing based on the location of an object (e.g., a user) upon the detection of a third sensing event (i.e., an indication of a user's location near a dense node arrangement), a user can be located, and an appropriate set of RF-based sensing can be formed to allow for sleep monitoring of the user when both users are sleeping in a double bed or even when only one user is sleeping while the other is still awake. For example, sleep monitoring including respiratory rate recognition can allow for the determination of a user's health status.

[0061] In another aspect of the invention, a method is provided for performing RF-based sensing in an RF system comprising a plurality of nodes for performing RF-based sensing. At least two of the plurality of nodes are included in a dense node arrangement. The method includes the following steps: - Form a first group of nodes that includes at least one node in a dense node arrangement. - Form a second group of nodes, including at least one node from the first group and at least one additional node in a dense node arrangement. - The first group performs RF-based sensing in the first sensing area to detect a first sensing event indicating the presence of an object in the first sensing area, and If a first sensing event is detected, the second group performs RF-based sensing in a second sensing region that at least partially overlaps with the first sensing region to identify a second sensing event indicating object activity.

[0062] A first group can be formed, such that the first group includes at least one node in the dense node arrangement and at least one node not included in the dense node arrangement.

[0063] The method may additionally include one or more of the following steps: - Upon detection of a first sensing event, at least one node of the first group performs RF-based sensing in a third sensing region to detect a third sensing event indicating the location of an object near a dense node arrangement. The third sensing region at least partially overlaps with the first and second sensing regions. Furthermore, upon detection of both the first and third sensing events, RF-based sensing performed by the second group is conducted at the location of the object to identify a second sensing event. - A second group is formed upon detection of a third sensing event and based on the object's location. -Based on one or more RF system parameters and / or activities to be identified by the second group, the first group is formed by selecting nodes to be included in the first group. -Based on one or more RF system parameters and / or activities to be identified by the second group, the second group is formed by selecting at least one additional node in a dense node arrangement to be included in the second group, in addition to the nodes of the first group. - The nodes in the RF system adjust the message frequency used to transmit RF messages to perform RF-based sensing based on which sensing event the node wants to detect or identify. - The nodes in the RF system adjust the directionality of RF messages to perform RF-based sensing based on which sensing event the node wants to detect or identify. - When the second group performs RF-based sensing in the second sensing area to identify a second sensing event, stop performing RF-based sensing for detecting any other sensing events in the second sensing area. - A second group performs RF-based sensing in the second sensing area to identify a second sensing event until a stop condition is met, wherein the stop condition includes one or more of the following: a second event is identified, a stop event is detected, a predetermined duration has elapsed since the second group began RF-based sensing in the second sensing area to identify the second sensing event, and inactivity of the identified object is detected. - When the second group stops performing RF-based sensing for detecting the second sensing event, RF-based sensing for detecting the first or third sensing event is performed, and - Perform actions based on the detected first sensing event, the detected third sensing event, the identified second sensing event, and / or contextual information.

[0064] In another aspect of the invention, a computer program product is provided for performing RF-based sensing in an RF system comprising a plurality of nodes for performing RF-based sensing. At least two of the plurality of nodes are included in a dense node arrangement. The computer program product includes program code means which, when the computer program product is run on a processor, causes the processor to perform the method according to at least one of claims 11 to 13 or any embodiment of the method.

[0065] In another aspect, a computer-readable medium is proposed that has stored the computer program product of claim 14. Alternatively or additionally, the computer-readable medium may enable the storage of a computer program product according to any embodiment of the computer program product.

[0066] It should be understood that the RF system of claim 1, the RF super system of claim 10, the method of claim 11, the computer program product of claim 14, and the computer-readable medium of claim 15 have similar and / or identical preferred embodiments, particularly as defined in the dependent claims.

[0067] 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.

[0068] These and other aspects of the invention will become clear and will be explained with reference to the embodiments described below. Attached Figure Description

[0069] In the following figures: Figure 1The nodes of an RF system are illustrated schematically and exemplary; Figure 2 An embodiment of an RF system performing presence detection is illustrated schematically and exemplary; Figure 3 An embodiment of an RF system performing proximity detection is illustrated schematically and exemplary; Figure 4 An embodiment of an RF system for performing activity identification is illustrated schematically and exemplary; Figure 5 An embodiment of the RF supersystem is illustrated schematically and exemplary; and Figure 6 An embodiment of a method for performing RF-based sensing in an RF system with a dense node arrangement is shown. Detailed Implementation

[0070] Figure 1 The node 10 of the RF system is illustrated schematically and exemplary, for example. Figures 2 to 4 The connected lighting (CL) system 100 presented in the middle or Figure 5 The CL system 400 or 400' is presented in the diagram. Node 10 is a illuminator that provides illumination and is used to perform RF-based sensing.

[0071] In a CL system, nodes can be, for example, routers, bridges, lights, illuminators, switches, or sensors. This allows the use of the CL system's wireless infrastructure to perform RF-based sensing, thereby increasing the functionality of the CL system. These nodes can perform their functions, such as providing light and receiving control commands, and additionally perform RF-based sensing. RF-based sensing can be used, for example, for presence detection and activity recognition, such as respiratory rate measurement, heart rate measurement, posture recognition, fall detection, or for performing other sensing applications.

[0072] Node 10 includes functional units in the form of a control unit 12, a transceiver unit 14, an antenna array 16, and an illumination unit 17. Instead of an antenna array, a single antenna may also be included in the node.

[0073] The control unit 12 includes a computer-readable medium in the form of a processor 18 and a memory 20.

[0074] In this embodiment, transceiver unit 14 includes a WiFi transceiver 22 and a BLE transceiver 24. In this embodiment, the WiFi transceiver 22 uses WiFi communication technology according to one or more WiFi standards (such as IEEE 802.11ax, IEEE 802.11ay, and / or any other communication protocol). The BLE transceiver 24 uses BLE communication technology. In this embodiment, the BLE transceiver 24 can operate on multiple different channels. In other embodiments, various other communication technologies can be used, such as Zigbee, cellular radio, Thread, or any other communication technology.

[0075] Transceiver unit 14 uses antenna array 16 to transmit RF signals to and receive RF signals from nodes in the CL system to wirelessly exchange data between nodes and perform RF-based sensing. RF signals transmitted from one node to another are subject to interference from objects within a specific volume between nodes. RF signals interfered with by objects within the specific volume can be analyzed in control unit 12. RF signals can use WiFi or BLE communication technologies. In other embodiments, the transceiver unit's transceiver can be used to perform RF-based sensing by transmitting RF signals into a specific volume and by receiving and analyzing RF signals reflected from the specific volume by the same node. RF signals can also be transmitted from one node into a specific volume, and interfered and / or reflected RF signals can be received and analyzed by another node.

[0076] The lighting unit 17 includes a driver and a light source for providing light, such as an array of light-emitting diodes (LEDs).

[0077] The memory 20 of the control unit 12 stores a computer program product for performing RF-based sensing. This computer program product includes program code means for causing the processor 18 to execute methods for performing RF-based sensing when the computer program product is run on the processor 18, such as... Figure 6 The method shown is described. Memory 20 also includes a computer program product for operating node 10 and optionally a CL system, for example, for controlling the functions of the node and the functions of the node controlling the CL system, for example, to provide illumination and for performing RF-based sensing.

[0078] In addition, memory 20 stores RF system parameters, including, for example, node locations, regions of interest for expected sensing events, distances between nodes, or any other RF system parameters. Additionally, memory 20 stores settings for RF-based sensing parameters used to perform RF-based sensing, such as channel, message frequency, sensing area, group, or any other RF-based sensing parameters.

[0079] Figure 2 A presence detection (CL) system 100 is illustrated. The CL system 100 includes multiple nodes 10, 27, 28, 29, and 30 for performing RF-based sensing. Five of the nodes 10 are arranged in a dense node arrangement in the form of a chandelier 26. The nodes 10 in the chandelier 26 have a node density of 10 nodes per square meter. In other embodiments, the node density in the dense node arrangement may also be, for example, at least 5 nodes per square meter or more than 10 nodes per square meter. The chandelier 26 is also connected to an external server 200. The CL system 100 is arranged in a room (not shown) within a building. In other embodiments, the CL system may also be arranged, for example, in an open space, such as part of a street lighting system.

[0080] In this embodiment, the external server 200 controls the CL system 100, that is, controls the normal operation of the nodes of the CL system, such as providing lighting and RF-based sensing. RF messages are transmitted between nodes via RF signal 34. RF messages may include RF data messages and RF sensing messages. RF data messages, such as control commands, are used to activate or deactivate functions, such as providing lighting to a node. RF sensing messages are used to perform RF-based sensing. In this embodiment, RF sensing messages are not exchanged between nodes in a dense node arrangement, but only between other nodes and nodes in a dense node arrangement. In other embodiments, RF sensing messages may also be exchanged between each node. The CL system 100 performs RF-based sensing for various sensing applications, such as to detect the presence of an object in the form of a user 32.

[0081] RF-based sensing requires varying numbers of nodes and message frequencies depending on the sensing application, such as presence detection, proximity detection, or activity recognition, as different applications require different levels of accuracy. For example, recognizing the activity (e.g., gesture) of user 32 requires more nodes and a higher message frequency compared to detecting the presence of user 32 or user 32's proximity to a densely packed node array (e.g., chandelier 26). Higher message frequencies and more nodes transmitting RF messages can lead to wireless interference between activity recognition and normal operation of the CL system, such as data exchange between nodes used to control the CL system. To maintain low wireless interference, the number of nodes simultaneously performing RF-based sensing should be kept to the minimum required for the respective sensing application. Therefore, the CL system is calibrated, and additional nodes are only activated for performing RF-based sensing to increase resolution when needed, such as for activity recognition. CL system calibration involves finding the optimal number, physical location, and configuration of nodes for presence and proximity detection and activity recognition. This allows for timely and accurate detection, resulting in the desired low-latency control of the nodes. Thus, the CL system can respond to control commands transmitted via RF data messages, such as activating a lighting scene using a switch or changing the color of a illuminator using a device running a corresponding app.

[0082] In the following text, refer to Figures 2 to 4 The functionality of CL system 100 is explained.

[0083] In short, the CL system 100 first calibrates groups to perform RF-based sensing for a specific sensing application within the sensing areas associated with the corresponding groups. The first group of detected objects is in Figure 2 The presence of the object in the first sensing area. Optionally, the presence detection is stopped, and the third set of detections detects the proximity of the densely arranged objects, and optionally determines the object relative to the first sensing area. Figure 3 The current position of the densely packed nodes in the array. Then, presence detection and proximity detection are stopped, and the second set of identifications is performed. Figure 4 The activity of objects within the system is monitored. When activity recognition is no longer needed, it stops, and presence detection or optional proximity detection is performed again. The CL system 100 can perform an action when a first sensing event, a third sensing event, and / or when a second sensing event is detected. The action performed by the CL system 100 can depend on the sensing event; for example, lighting can be activated when the presence of a user is detected, lighting can be deactivated when the presence of a user is no longer detected, and a corresponding lighting scene can be activated when a gesture is detected. Additionally, contextual information can be considered for this action.

[0084] In the following text, we explain in more detail the steps performed by the CL system 100.

[0085] First, the CL system 100 performs calibration by selecting nodes to be added to the appropriate groups to perform RF-based sensing for detecting or identifying individual sensing events. In this embodiment, three groups are formed: a first group for presence detection, a third group for proximity detection, and a second group for activity identification. In other embodiments, a different number of groups may be formed, such as two groups.

[0086] The first group has been optimized for presence detection. For example... Figure 2 As shown, nodes are included in a first group that allows for optimal presence detection. In this embodiment, the center node of chandelier 26 is included in the first group, and nodes 27, 28, 29, and 30 are not included in chandelier 26; that is, the first group includes one node in a dense node arrangement and several nodes not included in the dense node arrangement. In other embodiments, the RF system may also form the first group of nodes such that it includes only one or more nodes in a dense node arrangement, i.e., nodes not included in the dense node arrangement. Furthermore, the settings of RF-based sensing parameters of the first group of nodes are adjusted, such as the directionality, channel, and message frequency used by the nodes to perform RF-based sensing, to optimize the presence detection of the first group of nodes. Finally, a first sensing area 40 associated with the first group is defined. In this embodiment, the first sensing area 40 depends on the location of the nodes included in the first group.

[0087] A third group of nodes is selected to optimize proximity detection, for example, detecting user locations near densely packed nodes. In this embodiment, the third group includes the nodes from the first group plus two additional nodes from the chandelier 26, such as... Figure 3 As shown. In other embodiments, other nodes may be included in the third group. Furthermore, the RF-based sensing parameters of the nodes in the third group are adjusted to optimize their use for proximity detection. Finally, a third sensing region 50 associated with the third group is defined, which depends on the location of the nodes included in the third group.

[0088] The second group is optimized for the recognition activity. The second group includes all nodes from the first group, and additionally includes all nodes from chandelier 26, such as... Figure 4As shown. Therefore, the second sensing group is a superset of the first group. In other embodiments, other nodes may be included in the second group. Nodes to be included in the second group can be selected based on various parameters, such as the sensing application and the distance from the user to the dense node arrangement. Furthermore, the RF-based sensing parameters of the nodes in the second group are adjusted to optimize activity recognition. Finally, a second sensing region 60 associated with the second group is defined. In this embodiment, the second sensing region depends on the location of the nodes included in the second group, and particularly on the location of the dense node arrangement. The second sensing region is defined such that it is located near the dense node arrangement to optimally cover the region of interest where user activity will be performed.

[0089] Calibration can include obtaining feedback from users 32 to optimize these groups for their respective sensing applications. For example, groups can be calibrated based on the physical configuration of the nodes (i.e., the location of the nodes) and user preferences (e.g., what types of activities should be tracked or expected of users 32, such as cooking, training, or playing games). Users 32 can support the calibration of the CL system 100 by providing feedback on latency levels that they deem acceptable. Furthermore, the CL system can be trained to identify user activities based on activities performed by the user in different parts of the room. Users can generate training data in this way. The training data can be labeled and fed as input data to activity recognition algorithms, such as machine learning (ML) algorithms including neural networks. This can be used when adjusting directionality, channels, and message frequencies, and when selecting nodes to include in the appropriate groups to optimize the groups for RF-based sensing for the corresponding sensing applications.

[0090] In other embodiments, the RF system may form a second set based on the location of the object upon detection of a third sensing event, i.e., during operation of the CL system 100, or in other words, during operation of the CL system 100 performing RF-based sensing.

[0091] Once the CL system 100 is calibrated, it can be used to perform improved RF-based sensing.

[0092] Initially, the CL system 100 performs RF-based sensing in the first sensing area 40 using a first group to detect a first sensing event indicating the presence of user 32 in the first sensing area 40, such as... Figure 2As shown. In this embodiment, the central node of chandelier 26 and nodes 27, 28, 29, and 30 perform RF-based sensing with a message frequency of 30 Hz sufficient for presence detection. This sensing application does not interfere with the normal operation of the CL system 100, i.e., providing lighting and controlling the CL system 100. In other embodiments, presence detection may be the default operating mode of the RF system. Presence detection may be used, for example, to activate a security alarm or simply to automatically turn lights on and off, i.e., to activate and deactivate the lighting function of the node.

[0093] In this embodiment, when presence is detected, the CL system 100 activates the illuminator to provide illumination. In other embodiments, the RF system may also perform any additional actions upon detecting a first sensing event indicating the presence of an object (e.g., a user). The RF system can be configured to perform actions based on the detected first sensing event and / or contextual information.

[0094] Furthermore, upon detecting a first sensing event, the CL system 100 performs RF-based sensing in a third sensing area 50 using a third group to detect a third sensing event indicating the location of a user 32 near the dense node arrangement. This location can be a physical location, for example, having a direction and distance from the dense node arrangement, or a direction such as north, east, south, or west of the node arrangement. The third group has a higher node density than the first group because it includes two additional nodes in the dense node arrangement. Proximity detection requires a slightly higher resolution than presence detection, and proximity detection can be enabled due to the higher node density of the third group compared to the first group. Additionally, the third sensing area 50 partially overlaps with the first sensing area 40 and the second sensing area 60.

[0095] If a user is within a certain distance of the dense node arrangement (e.g., within 4 m of the outer surface of the dense node arrangement or the center of the dense node arrangement, such as within 4 m of the center node of the chandelier 26), proximity is detected.

[0096] In other embodiments, proximity detection can be used to provide individual control of nodes near the user's location. For example, it can be used for physical control, app-based, or voice-based commands. The RF system can be configured to perform actions upon and / or based on the detection of a third sensing event.

[0097] In this embodiment, the second group performs RF-based sensing in the second sensing area 60 to identify a second sensing event indicating the activity of user 32 when a third sensing event is detected (i.e., when the user's location is close to the dense node arrangement). Because proximity is detected, the first sensing event, i.e., the presence of the user, is also detected. The second group performs RF-based sensing only when user 32 is close to the dense node arrangement (i.e., the chandelier 26 in this embodiment) because activity identification requires a higher density of co-located nodes (i.e., nodes in the dense node arrangement). Additionally, the message frequency used by the second group to perform RF-based sensing is increased compared to the third group. This allows for the identification of activities, such as the posture of user 32. Due to the higher message frequency, wireless interference may be higher. Therefore, the CL system 100 can coordinate or orchestrate the transmission of RF messages, including RF data messages for controlling the CL system 100 and RF sensing messages for performing RF-based sensing. This orchestrated transmission of RF messages further allows for the reduction of wireless interference. Furthermore, the second group performs RF-based sensing only temporarily (e.g., for as short a time as possible) to reduce or avoid wireless interference.

[0098] In this embodiment, the second group performs RF-based sensing at the location of user 32. The second sensing area 60 at least partially overlaps with the first sensing area 40.

[0099] When the second group performs RF-based sensing in the second sensing area 60, the CL system 100 stops performing RF-based sensing for other sensing applications. In other embodiments, different sensing applications can be performed in parallel. Performing RF-based sensing for different sensing applications may include orchestrating the transmission of different RF sensing messages included in the transmitted RF signals to reduce or avoid wireless interference.

[0100] In this embodiment, the CL system 100 processes the identified activities, such as gait or posture, locally within a node. In other embodiments, activities can also be identified remotely, for example, on a server 200. Furthermore, different activities can be aggregated at a certain time before processing them. Aggregated activities can be processed together to identify them. Activities can be aggregated, for example, to provide contextual information to the aggregated activities. For example, combinations of postures can be identified to allow for the provision of more complex commands. The identified activities can be used as lookup keywords against a set of references. Artificial intelligence (AI) based algorithms can achieve more accurate and sophisticated identification.

[0101] RF systems can be configured to perform actions based on identified secondary sensing events and possible contextual information. For example, if cooking is detected, the node might brighten, or if romantic gestures are detected, the node might turn red. This allows users to turn on lights with simple gestures (such as waving) to specific settings, such as color settings or dimming levels. More complex context-aware actions can be performed based on additional contextual information. For example, more sophisticated control can be achieved by combining identified activity with contextual information obtained from other devices (e.g., smartphones). If, for example, contextual information in the form of GPS information from a user's smartphone detects that no user is home and that the main door has been opened, an alarm signal can be triggered and provided to the user's smartphone and / or another external server, such as a security company.

[0102] In other embodiments, nodes of the RF system may utilize directional antennas (e.g., for beamforming) to perform RF-based sensing in order to provide a narrower second sensing area 60.

[0103] The message frequency between nodes in a dense node arrangement and the node closest to user 32 (e.g., node 29) may be higher than that used for other nodes 27, 28, and 30. The message frequency between a node in a dense node arrangement and node 29 could be, for example, 1000 messages per second. The message frequency between the dense node arrangement and other nodes 27, 28, and 30 could be, for example, 300 messages per second. This can allow for further improvement in the resolution of the region of interest, i.e., at the user's location where expected user activity is expected.

[0104] The channel of the second group of nodes can also be adjusted. For example, the WiFi channel can be adjusted from 2.4 GHz to 5 GHz or 60 GHz. Higher frequencies can improve activity recognition, such as gesture recognition.

[0105] In this embodiment, the second group performs RF-based sensing to temporarily identify user activity, i.e., until a stopping condition is met. The stopping condition is the identification of a second event and the detection of an additional stopping event. The stopping event is when the user performs a stopping gesture, and this stopping gesture is identified by the second group. In other embodiments, the stopping condition may also include, for example, the identification of a second event, the detection of a stopping event, a predetermined duration elapsed since the second group began RF-based sensing in the second sensing area to identify the second sensing event, and the identification of one or more of the following: inactivity of the object. The stopping event may be defined by the user, for example, during calibration of the CL system 100. The stopping event may also be, for example, the user leaving the second sensing area.

[0106] In this embodiment, when the second group stops performing RF-based sensing for detecting the second sensing event, the CL system 100 performs RF-based sensing for detecting the first sensing event, i.e., presence detection. In other embodiments, when the second group stops performing RF-based sensing for detecting the second sensing event, the RF system may perform RF-based sensing for detecting the first or third sensing event. Whether the first or third group performs RF-based sensing to detect the first or third sensing event may depend on the stopping condition. For example, a user may leave the second sensing area. In this case, the first group may detect whether the user is still in the first sensing area, and the third group may subsequently detect whether the user has returned to the vicinity of the dense node arrangement. Alternatively, for example, the third group may detect whether the user is still near the dense node arrangement, and if the user is not near the dense node arrangement, the first group may perform RF-based sensing to detect whether the user is still in the first sensing area.

[0107] In other embodiments where the second group stops performing RF-based sensing, even if additional restart conditions are met (e.g., a predetermined duration has elapsed since the second group stopped performing RF-based sensing), the second group can simply resume RF-based sensing to identify the second sensing event. This can allow for reduced wireless interference because RF-based sensing by the second group can be avoided after the second sensing event has been identified and the user is still near a dense node deployment.

[0108] In yet another embodiment where the second group stops performing RF-based sensing, the second group can resume RF-based sensing to identify the second sensing event based on the second sensing event. For example, if the second sensing event indicates an activity in the form of a gesture command (e.g., "turn on entertainment lights" for a node to turn on lights for a specific lighting scene, or "go to sleep" for a node to turn off lights), it is unlikely that there will be a subsequent second sensing event to be identified. For example, if a user arrives home and enters a building, multiple sensing events can be expected. For example, a first gesture for turning on a light in the entrance can be identified, followed by a second gesture pointing to the living room for turning on a light in the living room. In another example, a user can enter the bathroom. In this case, the "turn on" gesture may be followed by a "turn off" gesture a few minutes later.

[0109] Figure 5 An RF super system 1000 is shown, which includes two RF systems in the form of CL system 500 and 500', with two dense node arrangements in the form of pendant lights 26 and 26' at different locations.

[0110] CL system 500 includes a chandelier 26 and nodes 29 and 30. CL system 500' includes a chandelier 26' and node 27. In this embodiment, the nodes of the RF super system 1000 exchange data, such as RF messages, including RF data messages and RF sensing messages for performing RF-based sensing. Chandelier 26 is also connected to an external server 200. The external server 200 can be used to control the RF super system 1000. Alternatively, the nodes of the RF super system 1000 can also be controlled locally, for example via a switch or remote control (not shown). CL systems 500 and 500' have information regarding... Figures 2 to 4 The CL system 100 shown in the embodiment has similar functionality to that described.

[0111] Figure 6 An embodiment of a method 600 for performing RF-based sensing in an RF system is shown, the RF system including multiple nodes for performing RF-based sensing, such as... Figures 2 to 4 The CL system 100 is shown. At least two of the multiple nodes are included in a dense node arrangement. First, the method calibrates the RF system, thus forming a node group.

[0112] In step 602, a first group of nodes is formed. In this embodiment, the first group includes at least one node in a dense node arrangement and at least one node not included in the dense node arrangement. In other embodiments, the first group may also include only at least one node in the dense node arrangement. The first group is formed by selecting nodes to be included in the first group based on one or more radio frequency system parameters. In other embodiments, nodes may be selected additionally or alternatively based on a second sensing event to be identified by a second group. The first group of nodes is configured by adjusting the directionality, channel, and message frequency of the first group of nodes used to perform RF-based sensing (i.e., presence detection) based on the first sensing event. Furthermore, a first sensing region is defined. In this embodiment, the first sensing region depends on the location of the first group of nodes.

[0113] In step 604, a second group of nodes is formed. The second group of nodes includes the first group of nodes and at least one additional node in the dense node arrangement. The second group is formed based on one or more RF system parameters by selecting at least one additional node from the dense node arrangement to be included in the second group, in addition to the nodes from the first group. In other embodiments, nodes may be selected additionally or alternatively based on second sensing events to be identified by the second group. The second group of nodes is configured by adjusting the directivity, channel, and message frequency of the nodes used to perform RF-based sensing based on the second sensing events to be identified. Furthermore, a second sensing area is defined.

[0114] In step 606, the first group performs RF-based sensing in the first sensing area to detect a first sensing event. The first sensing event indicates the presence of a user in the first sensing area. In other embodiments, the first sensing event may also indicate the presence of any other object in the first sensing area. Step 606 is performed until the first sensing event is detected, i.e., until a user is detected. Then step 606 is stopped, i.e., presence detection stops, and optionally step 608 or step 610 is performed.

[0115] In step 608, upon detecting a first sensing event, nodes from the first group perform RF-based sensing in a third sensing region to detect a third sensing event. The third sensing event indicates the user's location near the dense node arrangement. The third sensing region at least partially overlaps with the first sensing region. In other embodiments, additional nodes (e.g., nodes from a second group) may be added to the first group to improve resolution. A third group may be formed to perform RF-based sensing to detect the third sensing event. When the user's location is detected to be near the dense node arrangement (here, within a certain distance, e.g., 4 m from the center of the dense node arrangement), step 608 is stopped, i.e., proximity detection is halted.

[0116] Step 608 is optional. Alternatively, step 610 can be performed when the presence of a user is detected in the first sensing area.

[0117] In other embodiments, a second group is formed or adjusted upon detection of a third sensing event and based on the object's location.

[0118] In step 610, the second group performs RF-based sensing in the second sensing area to identify a second sensing event indicating user activity. In this embodiment, the second sensing area is a subset of the first sensing area and is narrowed to the area surrounding the user's position by beamforming. In other embodiments, if proximity detection is performed, the second sensing area may at least partially overlap with the first sensing area and optionally at least partially overlap with a third sensing area. Furthermore, if the first sensing event is detected and, upon detection of the third sensing event, the second group may perform RF-based sensing at the object's location to identify the second sensing event. In this embodiment, the activity to be identified is the user's gesture for controlling the RF system. Different gestures may allow the activation of different lighting scenarios.

[0119] In this embodiment, instead of performing other RF-based sensing to detect other sensing events, a second group performs RF-based sensing in the second sensing area to identify the second sensing event.

[0120] The second group performs RF-based sensing in the second sensing area to identify a second sensing event until a stopping condition is met. In this embodiment, the stopping condition is identifying the second event, i.e., identifying a user's gesture for controlling the RF system, and additionally identifying a stopping event. In this embodiment, the stopping event is either the user leaving the first sensing area or the user's location no longer being near the dense node arrangement. For example, if the user's presence is not detected in the first sensing area by the first group performing RF-based sensing, the user leaving the first sensing area can be detected, and the detection that the user's location is no longer near the dense node arrangement can be detected, for example, by at least one node of the first group performing RF-based sensing in the third sensing area. In other embodiments, the stopping condition may include, for example, a predetermined duration that has elapsed since the last gesture was identified. In other embodiments, the stopping condition may include one or more of the following: identifying the second event, detecting the stopping event, a predetermined duration that has elapsed since the second group began RF-based sensing in the second sensing area to identify the second sensing event, and identifying inactivity of an object.

[0121] If step 610 stops, either RF-based sensing for detecting the first sensing event is performed (i.e., step 606), or a third sensing event is performed (i.e., step 608). Which step is performed depends on whether the stopping condition is met. For example, if the user leaves the first sensing area, step 606 is performed, i.e., presence detection. If the user is still in the first sensing area, but her location is no longer near the dense node arrangement, step 608 is performed, i.e., proximity detection.

[0122] In step 612, an action is performed upon and based on the detected second sensing event, i.e., the lighting scene is activated depending on the identified pose. If step 610 does not stop, step 610 can be performed in parallel with step 612; that is, several poses can subsequently be identified to adjust the lighting scene. In other embodiments, other actions can be performed based on the detected first sensing event, the detected third sensing event, the identified second sensing event, and / or contextual information. For example, other actions can also be performed upon the detection of the first sensing event, the third sensing event, and / or contextual information, and / or the identification of the second sensing event.

[0123] While the invention has been detailed and described in the accompanying drawings and the foregoing description, such description should be considered illustrative or exemplary and not limiting; the invention is not limited to the disclosed embodiments. For example, it is possible to operate the invention in embodiments where the RF system is a heating, ventilation, and air conditioning (HVAC) system or any other smart home or building management system (BMS).

[0124] 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.

[0125] In the claims, the words “comprising” and “including” do not exclude other elements or steps, and the indefinite articles “a” or “an” do not exclude a plurality.

[0126] A single unit, processor, or device can perform the functions of several items listed in the claims. The mere fact that certain measures are referenced in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously.

[0127] Operations performed by one or more units, nodes, or devices (e.g., forming a first group of nodes including at least one node in a dense node arrangement; forming a second group of nodes including at least one node from the first group and at least one additional node in the dense node arrangement; performing RF-based sensing by the first group in a first sensing area to detect a first sensing event indicating the presence of an object in the first sensing area; if the first sensing event is detected, performing RF-based sensing by the second group in a second sensing area that at least partially overlaps with the first sensing area to identify a second sensing event indicating object activity; etc.) can be performed by any other number of units, nodes, or devices. These operations and / or methods can be implemented as program code means of a computer program and / or as dedicated hardware.

[0128] Computer program products may be stored / distributed on suitable media, such as optical storage media or solid-state media, provided together with or as part of other hardware; but may also be distributed in other forms, such as via the Internet, Ethernet, or other wired or wireless telecommunications systems.

[0129] Any reference numerals in the claims should not be construed as limiting the scope.

[0130] This invention relates to performing RF-based sensing in an RF system comprising multiple nodes, at least two of which are included in a dense node arrangement. A first group of nodes is formed, comprising at least one node in the dense node arrangement, and a second group of nodes is formed, comprising at least one node from the first group and at least one additional node from the dense node arrangement. The first group performs RF-based sensing in a first sensing region to detect a first sensing event indicating the presence of an object in the first sensing region. If the first sensing event is detected, the second group performs RF-based sensing in a second sensing region that at least partially overlaps with the first sensing region to identify a second sensing event indicating object activity.

Claims

1. A radio frequency system (100; 500, 500') including a plurality of nodes (10, 27, 28, 29, 30) for performing radio frequency-based sensing. At least two of the plurality of nodes (10, ..., 30) are included in a dense node arrangement (26), wherein the dense node arrangement comprises a multi-node device and / or a set of densely packaged nodes; and The radio frequency system (100; 500, 500') is configured to: - Form a first group of nodes (10, ..., 30) including at least one node (10) in the dense node arrangement (26). - Form a second group of nodes (10, ..., 30) including at least one node (10) of the first group and at least one additional node (10) in the dense node arrangement (26). - Radio frequency-based sensing is performed by the first group in the first sensing area (40) to detect a first sensing event indicating the presence of an object (32) in the first sensing area (40), and wherein if the first sensing event is detected, the radio frequency system (100; 500, 500') is further configured to: - In a second sensing region (60) that at least partially overlaps with the first sensing region (40), a second group performs radio frequency-based sensing to identify a second sensing event indicating the activity of the object (32).

2. The radio frequency system (100; 500, 500') according to claim 1, wherein the radio frequency system (100; 500, 500') is configured to form the first group of nodes, such that the first group includes at least one node (10) in the dense node arrangement (26) and at least one node (27, 28, 29, 30) not included in the dense node arrangement (26).

3. The radio frequency system (100; 500, 500') according to claim 1 or 2, wherein upon detection of the first sensing event, the radio frequency system (100; 500, 500') is configured to perform radio frequency-based sensing in a third sensing region (50) via at least one node (10) of at least the first group to detect a third sensing event indicating the location of the object (32) near the dense node arrangement (26), the third sensing region (50) at least partially overlapping the first sensing region (40) and the second sensing region (60), and The radio frequency system (100; 500, 500') is configured to perform radio frequency-based sensing at the location of the object (32) by the second group to identify the second sensing event in the event of detecting the first sensing event and in the event of detecting the third sensing event.

4. The radio frequency system of claim 3, wherein the radio frequency system (100; 500, 500') is configured to form the second group upon detection of the third sensing event and based on the position of the object (32).

5. The radio frequency system (100; 500, 500') according to claim 1 or 2, wherein the radio frequency system (100; 500, 500') is configured to adjust the message frequency for transmitting radio frequency messages by the nodes (10, ..., 30) of the radio frequency system (100; 500, 500') to perform radio frequency-based sensing, adjust the directionality of radio frequency message transmission, or adjust the message frequency for transmitting radio frequency messages by the nodes (10, ..., 30) of the radio frequency system (100; 500, 500') to perform both radio frequency-based sensing and radio frequency message transmission directionality, based on which sensing event the nodes (10, ..., 30) want to detect or identify.

6. The radio frequency system (100; 500, 500') according to claim 1 or 2, wherein the radio frequency system (100; 500, 500') is configured to stop performing radio frequency-based sensing for detecting any other sensing event in the second sensing area (60) when radio frequency-based sensing is performed by the second group in the second sensing area (60) to identify the second sensing event.

7. The radio frequency system (100; 500, 500') according to claim 1 or 2, wherein the radio frequency system (100; 500, 500') is configured to perform radio frequency-based sensing in the second sensing area (60) by the second group to identify the second sensing event until a stop condition is met, the stop condition including one or more of the following - Identify the second event, - A stop event was detected. -A predetermined duration has elapsed since the second group began radio frequency-based sensing in the second sensing area (60) to identify the second sensing event, and - Identify the inactivity of the object (32).

8. The radio frequency system (100; 500, 500') of claim 3, wherein the radio frequency system (100; 500, 500') is configured to perform radio frequency-based sensing for detecting the first sensing event or the third sensing event when the second group stops performing radio frequency-based sensing for detecting the second sensing event.

9. The radio frequency system (100; 500, 500') of claim 3, wherein the radio frequency system (100; 500, 500') is configured to perform actions based on a detected first sensing event, a detected third sensing event, an identified second sensing event, and / or context information.

10. A radio frequency super system (1000) comprising two or more radio frequency systems (100; 500, 500') according to any one of claims 1 to 9, such that the radio frequency super system (1000) comprises two or more densely arranged nodes at different locations.

11. A method for performing radio frequency-based sensing in a radio frequency system (100; 500, 500'), the radio frequency system (100; 500, 500') including a plurality of nodes (10, ..., 30) for performing radio frequency-based sensing, wherein at least two of the plurality of nodes (10, ..., 30) are included in a dense node arrangement (26), wherein the dense node arrangement includes a multi-node device and / or a set of densely packaged nodes; The method includes the following steps: - Form a first group of nodes including at least one node (10) in the dense node arrangement (26), - Form a second group of nodes including at least one node (10) of the first group and at least one additional node (10) of the dense node arrangement (26), - The first group performs radio frequency-based sensing in a first sensing area (40) to detect a first sensing event indicating the presence of an object (32) in the first sensing area (40), and wherein if the first sensing event is detected, the method includes the following steps: - A second group performs radio frequency-based sensing in a second sensing region (60) that at least partially overlaps with the first sensing region (40) to identify a second sensing event indicating the activity of the object (32).

12. The method for performing radio frequency-based sensing in a radio frequency system (100; 500, 500') according to claim 11, wherein the first group is formed such that the first group includes at least one node (10) in the dense node arrangement (26) and at least one node (27, 28, 29, 30) not included in the dense node arrangement (26).

13. The method for performing radio frequency-based sensing in a radio frequency system (100; 500, 500') according to claim 11 or 12, comprising one or more of the following steps: - Upon detection of the first sensing event, at least one node (10, ..., 30) of the first group performs radio frequency-based sensing in a third sensing region (50) to detect a third sensing event indicating the location of the object (32) near the dense node arrangement (26), the third sensing region (50) at least partially overlapping the first sensing region (40) and the second sensing region (60), and wherein, upon detection of the first sensing event and upon detection of the third sensing event, radio frequency-based sensing performed by the second group is performed at the location of the object (32) to identify the second sensing event. - The second group is formed upon detection of the third sensing event and based on the position of the object (32). -Based on one or more radio frequency system parameters and / or a second sensing event to be identified by the second group, the first group is formed by selecting nodes (10, ..., 30) to be included in the first group. -Based on one or more radio frequency system parameters and / or a second sensing event to be identified by the second group, the second group is formed by selecting at least one additional node (10) from the dense node arrangement (26) to be included in the second group, in addition to the nodes (10, ..., 30) of the first group. - Adjust the message frequency used by the nodes (10, ..., 30) of the radio frequency system (100; 500, 500') to transmit radio frequency messages, for performing radio frequency-based sensing based on which sensing event the nodes (10, ..., 30) want to detect or identify. - Adjust the directionality of radio frequency messages from nodes (10, ..., 30) of the radio frequency system (100; 500, 500') to perform radio frequency-based sensing based on which sensing event the nodes (10, ..., 30) want to detect or identify. - When the second group performs radio frequency-based sensing in the second sensing area to identify the second sensing event, stop performing radio frequency-based sensing for detecting any other sensing events in the second sensing area (60). - The second group performs radio frequency-based sensing in the second sensing area (60) to identify the second sensing event until a stop condition is met, wherein the stop condition includes one or more of the following: identifying the second event, detecting a stop event, a predetermined duration has elapsed since the second group started radio frequency-based sensing in the second sensing area (60) to identify the second sensing event, and identifying inactivity of the object (32). - When the second group stops performing radio frequency-based sensing for detecting the second sensing event, radio frequency-based sensing for detecting the first sensing event or the third sensing event is performed, and - Perform actions based on the detected first sensing event, the detected third sensing event, the identified second sensing event, and / or contextual information.

14. A computer program product for performing radio frequency-based sensing in a radio frequency system (100; 500, 500'), the radio frequency system (100; 500, 500') including a plurality of nodes (10, ..., 30) for performing radio frequency-based sensing, wherein at least two of the plurality of nodes (10, ..., 30) are included in a dense node arrangement (26), wherein the computer program product includes program code means for causing the processor to perform a method for performing radio frequency-based sensing in a radio frequency system (100; 500, 500') according to any one of claims 11 to 13 when the computer program product is run on a processor.

15. A computer-readable medium having stored the computer program product of claim 14 for performing radio frequency-based sensing in a radio frequency system (100; 500, 500').

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