WO2022058244A1

WO2022058244A1 - Allocating nodes in groups in rf system

Info

Publication number: WO2022058244A1
Application number: PCT/EP2021/074951
Authority: WO
Inventors: Hugo José KRAJNC; Peter Deixler; Hendrik Stevens; Leendert Teunis Rozendaal; Sonia KATARIA
Original assignee: Signify Holding B.V.
Priority date: 2020-09-17
Filing date: 2021-09-10
Publication date: 2022-03-24

Abstract

The present invention relates to RF-based sensing in an RF system (100) comprising multiple nodes (10,..., 20) at different locations. At least two of the multiple nodes (12, 14) form a first group (28) of nodes that performs RF-based sensing in a first sensing area (30) for detecting a first sensing event. A second sensing event detection performance for performing RF-based sensing in the first sensing area (30) for detecting the first sensing event by the first group together with an additional node (20) or by the first group with one of the nodes (14) of the first group removed from the first group is determined. The second sensing event detection performance can be compared to a first sensing event detection performance for performing RF-based sensing by the first group (28). Based on the comparison it may be decided whether to add or remove a respective node (20, 14).

Description

Allocating nodes in groups in RF system

FIELD OF THE INVENTION

The present invention relates to a radio frequency (RF) system for performing RF-based sensing, a method for performing RF-based sensing, and a computer program product for performing RF-based sensing.

BACKGROUND OF THE INVENTION

WO 2020/043592 Al discloses a system for selecting one or more devices in a wireless network for transmitting, receiving and/or processing an RF signal for presence and/or location detection. The system comprises at least one processor configured to determine a suitability of each of a plurality of devices for transmitting, receiving and/or processing an RF signal 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 of the subset of devices to act as a device for transmitting, receiving and/or processing an RF signal for presence and/or location detection.

Spencer Bruce et. al. discloses method for selecting sensors when forecasting temperatures in smart building. DI discloses experiments from a smart house, in which different sets of sensors are selected, a temperature model from each set is built, and then the accuracy of these models is compared. The focus of DI is to reduce costs by reducing energy consumption, besides the cost of energy, the cost of data collection and management is considered. Each sensor employed in the forecast calculation incurs costs for installation and maintenance and an incremental cost for computation. Some sensors, however, may contribute little or no improvement to the forecast accuracy. Sets of sensors are incrementally constructed until the method arrives at a set for which no superset produces a better forecast. Then a successive series of subsets is constructed, such that forecast accuracy degrades slowly. As each sensor is removed, on the one hand, the forecast error increases, so the energy costs may increase for a given controller. On the other hand, the costs for installing sensors and for computing models are reduced. By considering this tradeoff over the series of sets, an optimal set of sensors can be found to be used with that controller. SUMMARY OF THE INVENTION

It can be seen as an object of the present invention to provide an RF system for performing RF-based sensing, a method for performing RF-based sensing, a computer program product for performing RF-based sensing, and a computer readable medium which allow improving sensing event detection performance in the RF system.

In a first aspect of the present invention an RF system is presented. The RF system comprises multiple nodes at different locations for performing RF-based sensing. At least two of the multiple nodes form a first group of nodes that is configured for performing RF-based sensing in a first sensing area for detecting a first sensing event. The RF system is configured for determining a second sensing event detection performance for performing RF- based sensing in the first sensing area for detecting the first sensing event by the first group together with an additional node or by the first group with one of the nodes of the first group removed from the first group.

Since the RF system is configured for determining a second sensing event detection performance for performing RF-based sensing in the first sensing area for detecting the first sensing event by the first group together with an additional node or by the first group with one of the nodes of the first group removed from the first group, the RF system may determine upfront, i.e., before adding the additional node to the first group or removing the node from the first group, whether this improves the sensing event detection performance. This may allow improving sensing event detection performance. This results in an improved RF-based sensing and operation of RF systems.

While typically an RF system with more nodes that contribute to RF-based sensing has a superior sensing event detection performance over an RF system with less nodes, there may be cases in which the sensing event detection performance is negatively affected by one or more of the nodes. A specific node may negatively contribute to the RF- based sensing, e.g., introduce a significant amount of noise, provide distorted RF signals, or be improperly positioned for performing RF-based sensing in the first sensing area of the first group. Determining the second sensing event detection performance allows to determine whether a specific node negatively contributes to RF-based sensing performed by the first group in the first sensing area of the RF system. This can allow to support the RF system in deciding whether the specific node should be removed from the first group, not added to the first group, or whether configuration parameters of the specific node should be adjusted in order to improve the sensing event detection performance. The RF system may be configured for determining a first sensing event detection performance for performing RF-based sensing in the first sensing area for detecting the first sensing event by the first group. The RF system may be configured for comparing the first sensing event detection performance with the second sensing event detection performance in order to determine whether adding the additional node to the first group or removing the one of the nodes of the first group from the first group improves the sensing event detection performance of the first group.

The first sensing area may be defined by the first group. For example, the first sensing area may be defined by locations of the nodes of the first group. Adding a node to or removing a node from the first group may in this case adjust the first sensing area. The first sensing area may also be a predetermined area of the RF system, e.g., a predetermined area in a building in which the RF system is arranged, such as a room within the building.

The RF system may include multiple groups of nodes which perform RF- based sensing in multiple sensing areas. The groups may have different sensing event detection performances depending on which nodes are included in the groups and a setting of their configuration parameters. The RF system may be included, for example, in a building and it may have groups of nodes for performing RF-based sensing in various rooms of the building. Each room may, for example, correspond to a sensing area in which one of the groups performs RF-based sensing. The nodes may additionally perform other tasks, such as providing light for luminaires or providing heating, cooling, air-conditioning for heating, cooling, air-conditioning (HVAC) devices.

The multiple nodes may include one or more luminaires for providing light as well as performing RF-based sensing. The multiple nodes may also include switches, sensors, or other RF devices, such as HVAC devices.

The additional node may be one of the multiple nodes or a node newly added to the RF system. The additional node may, for example, be a node included in one of the other groups of the RF system or a node which is not included in any group.

The first sensing event may be, for example, detection of presence, detection of occupancy, detection of proximity, fall detection, breathing detection, heartbeat detection, or recognition of an activity, such as a gesture.

The RF system may be configured for detecting an additional node. The RF system may furthermore be configured for detecting whether the additional node is capable of performing RF-based sensing. Additionally, the RF system may be configured for determining whether adding the additional node to one of its groups improves the sensing event detection performance of the respective group to which the additional node is added.

The RF system may be configured for adjusting a setting of configuration parameters of one or more of the nodes of the first group, the additional node, or one or more of the nodes of the first group and the additional node based on capabilities of the additional node, capabilities of one or more of the nodes of the first group, or capabilities of the additional node and one or more of the nodes of the first group in order to optimize the second sensing event detection performance. Adjusting the configuration parameters may allow to optimize the sensing event detection performance for nodes that would have negatively contributed to RF -based sensing when using their initial setting of configuration parameters. This may allow to improve RF -based sensing of the RF system. Furthermore, this may allow optimizing the sensing event detection performance of a group together with an additional node based on existing information of nodes of the first group or of the first group with the one of the nodes of the first group removed based on existing information of other nodes of the first group.

Adjusting the setting of the configuration parameters of one or more of the nodes of the first group may include adjusting the setting of the configuration parameters, for example, of the one of the nodes of the first group, of another one of the nodes of the first group, of two or more of the nodes of the first group, or of all of the nodes of the first group.

The capabilities of a node correspond to its abilities for perform tasks. The capabilities may include sensing capabilities for performing RF-based sensing and functional capabilities for performing other functions of the node, such as providing lighting, for example, if the node is a luminaire. The capabilities of the node depend on characteristics of the node and the setting of its configuration parameters. The characteristics of the node include a hardware configuration of the node which together with environmental influences the node experienced determine its characteristics. The environmental influences which the node experienced may have influenced its sensing event detection performance. For example, if the node was damaged, e.g., by falling on the ground, its sensing event detection performance may be reduced. The sensing capabilities of the node may include, for example, a reception capability, a transmission capability or any other sensing capability of the node for performing RF-based sensing. The reception capability depends, for example, on the hardware configuration of the node including, e.g., a number of antennas included in the node and/or a number of receivers included in the node, as well as on the setting of its configuration parameters including, e.g., a transmission power used by the node, communication protocols used by the node, frequency channels used by the node, or the like. The configuration parameters may also include a location of the node, a filtering process used by the node, a signal modification used by the node, a directionality of a wireless transmission, such as beam steering at 60 GHz Wi-Fi, or a directionality of a wireless reception, such as using an antenna array in Wi-Fi or any other configuration parameter.

The RF system may be configured for adding the additional node to the first group in dependence of the second sensing event detection performance. Alternatively, or additionally, the RF system may be configured for removing the one of the nodes of the first group from the first group in dependence of the second sensing event detection performance. Alternatively, or additionally, the RF system may be configured for adding the additional node to the first group and for removing the one of the nodes of the first group from the first group in dependence of the second sensing event detection performance. The RF system may be configured for adding the additional node to the first group, for example, if the second sensing event detection performance is better than the first sensing event detection performance. Alternatively, or additionally, the RF system may be configured for removing the one of the nodes of the first group from the first group if the second sensing event detection performance is better than the first sensing event detection performance. The RF system may also be configured for optimizing an allocation of the nodes to the first group based on determining the sensing event detection performance for different nodes in the first sensing area or in proximity of the first sensing area and adding and removing the nodes such that the sensing event detection performance is as good as possible. This allows improving the sensing event detection performance of the first group by adding or removing nodes.

The RF system may be configured for determining the second sensing event detection performance based on one or more of the following sensing event detection performance parameters: a similarity of the additional node or the one of the nodes of the first group to one or more of the nodes of the first group, a batch to which the additional node or the one of the nodes of the first group belongs, a contribution of the additional node or the one of the nodes of the first group to an overall baseline of the first group, capabilities of the additional node or the one of the nodes of the first group, one or more node characteristics of the additional node or the one of the nodes of the first group relevant for performing RF -based sensing, an amount of noise received or transmitted by the additional node or the one of the nodes of the first group, a setting of configuration parameters of the additional node or the one of the nodes of the first group.

The RF system may be configured for performing RF-based sensing by the first group and subsequently by the first group together with the additional node or with the one of the nodes of the first group removed from the first group. The RF system may be further configured for determining the first sensing event detection performance and the second sensing event detection performance and to compare them in order to determine whether the second sensing event detection performance is better or worse than the first sensing event detection performance. This allows to determine which allocation of the nodes to the first group has a better sensing event detection performance. The sensing event detection performance of the different allocations, e.g., first group, first group together with the additional node, first group with the one of the nodes of the first group removed from the first group, may also be determined and compared by performing RF-based sensing with the different allocations of the nodes interleaved with each other.

Alternatively, or additionally, the second sensing event detection performance may be determined by estimating it. In this case RF-based sensing does not need to be performed for the first group with the additional node or with the one of the nodes of the first group removed from the first group. Instead an expected second sensing event detection performance may be estimated. The second sensing event detection performance may be estimated, for example, based on rules or a sensing event detection performance formula.

Rules may be defined such that a node is added, not added, removed, or not removed based on a sensing event detection performance parameter comparison. The rules allow an upfront prediction whether adding the additional node or removing the one of the nodes of the first group from the first group will improve sensing event detection performance. For example, if the additional node or the one of the nodes of the first group is significantly noisier than other nodes of the first group, it is likely that the sensing event detection performance would be reduced by adding the additional node and improved by removing the one of the nodes of the first group from the first group. The RF system may be configured for accordingly adding, not adding, removing, or not removing the node, e.g., not adding the node if it is likely that the sensing event detection performance is reduced by adding the node. How large the noise amount received by a node is compared to a node of the first group, may for example be determined upon transmission of a single RF message by a node of the first group to the additional node or the one of the nodes of the first group and another node of the first group. The noise amount transmitted by a node compared to a node of the first group may be determined similarly. This allows to provide a performance metric based on relative increase or decrease of a sensing event detection performance parameter, such as the amount of noise.

The sensing event detection performance formula may, for example, include one or more sensing event detection performance parameters and respective weighting factors for each of them. The sensing event detection performance formula may provide a number which corresponds to the sensing event detection performance. This allows to calculate the first and the second sensing event detection performance and to compare them in order to decide whether or not to add or remove a node or more generally, how to allocate the nodes to groups.

The batch may be, for example, a batch or series for which sensing event detection performance is known to be good or bad. A node from a good batch is likely to improve the sensing event detection performance, while a node from a bad batch is likely to reduce the sensing event detection performance. The batch may be, for example, a manufacturing batch or a shipping batch. The RF system may be configured for determining the second sensing event detection performance to be reduced if the batch to which the additional node or the one of the nodes of the first group belongs is known to have RF sensing related issues, e.g., other nodes of the same batch showed an inferior sensing event detection performance or failed. The RF system may be configured for determining the second sensing event detection performance to be increased if the batch to which the additional node or the one of the nodes of the first group belongs is known to have a superior sensing event detection performance. The RF system may be configured for determining the second sensing event detection performance to be increased if the additional node or the one of the nodes of the first group belongs to the same batch of one or more of the nodes of the first group. Nodes may, for example, be from a same manufacturing batch if they are manufactured by the same manufacturer using the same process and materials at the same factory in a certain timeframe. Nodes may, for example, be from a same shipping batch if they were shipped together. Different shipping conditions of batches may significantly lower similarity even of nodes of a same manufacturing batch. For example, if the manufacturer stores manufactured nodes at different locations and the nodes are shipped to a third location, the shipping routes determine the environmental influences that the nodes experience. For example, if a storage is in China and another one in the USA and location for utilizing the node is in Canada, its shipping may be different in that the batch from China may be shipped in a container by a transport ship from China and transported by a truck from the USA. Shipping by ship may include a long time in the container with strong temperature cycles while transport by truck takes less time and may have less strong temperature cycles.

The RF system may furthermore be configured for not adding the additional node to the first group or for removing the one of the nodes of the first group from the first group if it is from a batch known to have RF sensing related issues. The RF system may alternatively or additionally be configured for adding the additional node to the first group or for not removing the one of the nodes of the first group from the first group if it is from a batch known to have a superior sensing event detection performance.

The sensing event detection performance may be considered to be improved when the contribution of the additional node or the one of the nodes of the first group to the overall baseline makes detection more reliable and possibly easier, respectively faster and reduced if it makes it less reliable and possibly harder, respectively slower. The contribution to the overall baseline may be determined, for example, by comparing the overall baseline of the first group with the overall baseline of the first group together with the additional node or with the one of the nodes of the first group removed from the first group. The overall baseline may be compared statically or dynamically, e.g., with a user walking around in the first sensing area.

The one or more node characteristics of the additional node or the one of the nodes of the first group relevant for performing radio frequency based sensing may include, for example, a hardware configuration, a total operating time of the node, an error state previously received from the node, or environmental influences that the node experienced. The characteristics influence the capabilities of the node and thus ultimately the sensing event detection performance.

The amount of noise received by the additional node or the one of the nodes of the first group may include how much noise is picked up in a multitude of frequency channels in case of a multi-channel protocol. If the node has a hardware issue, the amount of noise may be dominant in a specific frequency channel of the multitude of frequency channels.

The configuration parameters may include, for example, a location, a transmit power, a communication protocol, a frequency channel, or the like. The configuration parameters of the additional node may include, for example, a location of the additional node relative to the nodes of the first group. The configuration parameters of the one of the nodes of the first group includes, for example, a location of the one of the nodes of the first group relative to the other nodes of the first group.

The RF system may be configured for determining the similarity of the additional node or the one of the nodes of the first group to one or more of the nodes of the first group based on one or more similarity criteria.

The RF system may be configured for determining the similarity of the additional node to the one or more of the nodes of the first group, for example, by determining whether the additional node fulfills the one or more similarity criteria with the one or more of the nodes of the first group.

The similarity criteria include one or more of: a same batch to which the nodes belong, similar node characteristics relevant for performing radio frequency based sensing, similar environmental influences the nodes experienced, similar total operating times of the nodes, similar capabilities of the nodes, similar types of the nodes, similar settings of configuration parameters of the nodes, and similar baselines of the nodes.

Same batch may include a same manufacturing batch and/or a same shipping batch. The additional node or the one of the nodes of the first group may, for example, be in the same batch with one or more of the nodes of the first group.

Similar node characteristics relevant for performing RF -based sensing may include any node characteristics that are relevant for performing RF -based sensing, including, for example, node characteristics that are relevant for RF based data communication, such as node characteristics influencing transmission and reception capabilities of RF signals.

The similar environmental influences the nodes experienced include, for example, similar environmental conditions or similar events that the nodes experienced, such as temperature shocks, mechanical vibrations, take-off or landing accelerations when shipped by plane, shaking due to transport by ship, temperature swings, changes in humidity, or any other events which may influence the sensing event detection performance of the node. Environmental conditions may include, for example, a temperature, a humidity, an air movement, such as wind leading to mechanical vibrations of the node or parts of the node, or any other environmental condition. The environmental influences may influence the node characteristics relevant for performing RF-based sensing. For example, temperature shocks may cause an internal delamination of electronic components in a node resulting in wire bond damage, die damage or hairline cracks. The sensing event detection performance of the node may be reduced by such damage as it may influence the RF signals used in RF-based sensing. Some passive components might even get unsoldered due to cracks on solder joints between its leads and the printed circuit boards (PCBs).

The nodes may include one or more sensor units for sensing environmental influences during the lifetime of the node. The environmental influences may be stored in history data of the node, e.g., in a persistent memory. The history data may be stored, for example, in the RF system, e.g., in the node, or an external server to which the RF system can be connected. The external server may also store history data of other nodes of other RF systems including, for instance, nodes which experienced similar environmental influences. The history data may, e.g., include an error log which keeps track on temperature shock events, number of failures of the node, number of resets of the node, or the like. This allows to improve predicting the second sensing event detection performance, e.g., by comparing whether the nodes of the first group have a similar or worse error log as the additional node or the one of the nodes of the first group.

The node characteristics relevant for RF-based sensing may, for example, be determined based on the environmental influences the node experienced included in the history data. For example, a temperature shock during transport may reduce the sensing event detection performance. The node characteristics relevant for RF-based sensing additionally may be determined based on its hardware configuration, e.g., including specific components such as an antenna which is from a manufacturing batch with known RF sensing related issues. This may negatively influence the sensing event detection performance.

Similar types of nodes may be, for example, two versions of a luminaire of the same manufacturer, e.g., an old version and a new version which received a design makeover or which received a component change.

Similar settings of the configuration parameters of the nodes may include, for example, similar locations of the nodes. In order to be added to a group it is beneficial to be in proximity of the location of the nodes of the group. For example, if the nodes of a group are in a room on a first floor in a building and the additional node is in the 10th floor, it is likely that the sensing event detection performance is reduced by adding the additional node to the group. The RF system may be configured for adjusting a seting of configuration parameters of the additional node or the one of the nodes of the first group based on its similarity to the one or more of the other nodes of the first group.

The RF system may be configured for adjusting the seting of the configuration parameters of the additional node or the one of the nodes of the first group based on a seting of the configuration parameters of other nodes of the first group. This may improve calibrating the nodes for performing RF-based sensing, e.g., as improved default values or starting values for the configuration parameters may be provided based on the seting of the configuration parameters known for the other nodes of the first group. The similarity of the setings of the configuration parameters of the additional node or the one of the nodes of the first group to the other nodes of the first group, for example, also allows to estimate how much reconfiguration may be needed, e.g., changing a location or transmit power of the node in order to optimize the sensing event detection performance. The reconfiguration may be performed by a user.

The RF system may be configured for comparing a sub-baseline of the additional node or the one of the nodes of the first group to sub-baselines of the other nodes of the first group. In case that the sub-baselines are similar, no adjustment of the configuration parameters or calibration may be required.

The RF system may be configured for determining the second sensing event detection performance during a stable operational state and during a changing operational state of the additional node or the one of the nodes of the first group. This allows to determine whether the sensing event detection performance is improved even for cases in which it changes over operation time, e.g., the node changing from inactive to active. For example, the sensing event detection performance may drop only noticeable when the node changes its operational state or transitions between two operational states. For example, for a node in form of a luminaire changing its operational state may involve changing from not providing lighting to providing lighting, i.e., the luminaire starts from a cold state and is warmed up. This induces a temperature change resulting in thermal swings. The thermal swings in electronic components of the node may cause more noise to RF signals provided by the node, for example, as solder joints are affected by the temperature swings due to expansion and contraction of the electronic components of the node resulting in more noise.

A stable operational state may be achieved, for example, in case of a node providing light, if the node provides light for a certain time period for stabilizing the operational state, e.g., one minute, or if the node provides no light. A node may be determined to be in a stable operational state, for example, based on an internal temperature or current sensor of the node. In case the temperature or current determined by the internal temperature or current sensor is constant, the node may be determined to be in a stable operational state. Alternatively, temperature or current may also be estimated based on a model of temperature or current in dependence of on/off state and brightness over a certain time interval, which allows estimating the temperature or current, or at least whether the operational state is stable. The sensing event detection performance may be different in dependence whether it is determined for the stable operational state or during a changing operational state. Whether the additional node is added to the first group or not may depend on a sensing application, e.g., presence detection in a room without turning on a lighting function of the node in form of a luminaire.

The stable operational state may also include stable environmental condition and the changing operational state may include changing environmental condition. The environmental conditions may include, for example, a temperature, a humidity, an air movement, such as wind leading to vibrations of the node or parts of the node, or any other environmental condition.

At least two of the multiple nodes that are not included in the first group may form a second group of nodes. The second group may be configured for performing RF- based sensing in a second sensing area for detecting a second sensing event. The RF system may be configured for determining a fourth sensing event detection performance for performing RF-based sensing in the second sensing area for detecting the second sensing event by the second group together with the additional node or by the second group with one of the nodes of the second group removed from the second group.

The RF system may be configured for determining a third sensing event detection performance for performing RF-based sensing in the second sensing area for detecting the second sensing event by the second group. The RF system may be configured for comparing the fourth sensing event detection performance with the third sensing event detection performance in order to determine whether adding the additional node to the second group or removing the one of the nodes of the second group from the second group improves the sensing event detection performance of the second group. Furthermore, the RF system may be configured for comparing the fourth sensing event detection performance and the second sensing event detection performance in order to determine which of the first and second groups benefits more from adding the additional node to them or removing one of their nodes. The node removed from one of the groups may be added to the other of the groups if it improves the sensing event detection performance of the other group.

The RF system may also include more than two groups of nodes, such as three or more groups of nodes. Each group may, for example, perform RF-based sensing in a sensing area. Each node of the RF system may be allocated to one of the groups such that the sensing event detection performance of the RF system as a whole is optimized or for optimizing the sensing event detection performance for certain groups of the RF system.

The first sensing event and the second sensing event may be identical sensing events or different sensing events. Alternatively, or additionally, the different groups may be configured for performing RF-based sensing for detecting different or identical sensing events.

The RF system may be configured for optimizing an allocation of the additional node, the one of the nodes of the first group, and/or the one of the nodes of the second group to the first group and the second group based on the determined sensing event detection performances. This may allow improving the sensing event detection performances of the first group and the second group as well as the RF system as a whole.

The RF system may be configured, for example, for adding the additional node to the first group or to the second group based on the second sensing event performance and the fourth sensing event detection performance. The nodes may be allocated to the first group or the second group in dependence how the respective sensing event detection performance is influenced by adding the respective node to the respective group. For example, if the sensing event detection performance of one of the groups would increase while the sensing event detection performance of the other group would be decreased by adding the node, the node will be added to the group for which the sensing event detection performance is increased.

The RF system may also be configured for allocating the nodes of the RF system to the groups of the RF system such that the sensing event detection performances of the groups are optimized, i.e., the RF system may be configured for allocating all nodes to the groups.

The nodes may be swapped between groups, replaced in a group, removed from a group, or added to a group of nodes. Replacing corresponds to removing a first node from one of the groups and adding a second node to the one of the groups. Swapping corresponds to removing a first node from one of the groups, removing a second node from the other group, and adding the second node to the one of the groups and adding the first node to the other group. For example, a node in form of an Al 9 lamp in a living room may be swapped with a lamp in a bedroom.

Allocating the nodes may be performed automatically or involve a user. The user may, for example, adapt the location of the nodes, such as swapping the location of two nodes physically.

The RF system may be configured for determining the sensing event detection performance of one or more of the nodes of the groups of the RF system based on a node checking event. The node checking event may include, for example, detecting an additional node, adding an additional node, removing a node, or swapping a node. The node checking event may also include time based events, such as a certain duration has passed since the sensing event detection performance has been determined.

The RF system may be configured for adjusting configuration parameters of one or more of the nodes of the groups and the additional node based on capabilities of one or more of the nodes of the groups, based on capabilities of the additional node, or based on capabilities of one or more of the nodes of the groups and the additional node in order to optimize the sensing event detection performances.

The RF system may be configured for optimizing the allocation of the additional node, the one of the nodes of the first group, and/or the one of the nodes of the second group to the first group and the second group additionally based on a respective sensing application performed by the first group and a respective sensing application performed by the second group.

The RF system may be configured for allocating the nodes of the RF system to the groups of the RF system based on respective sensing applications performed by the groups. For example, the RF system may be configured for allocating the nodes such that all groups are able to perform their respective sensing applications. For example, a group performing presence sensing may need less nodes than another group performing motion sensing or gesture recognition. This may allow an optimized allocation of nodes that improves the functionality of the RF system.

The RF system may be used, for example, in private houses in which additional nodes are added over time or for office buildings in which aging nodes are replaced over time. The RF system may also be used for any other RF-based sensing application in which reconfiguration of groups of nodes is required over time. In a further aspect of the present invention a method for performing RF -based sensing in an RF system comprising multiple nodes at different locations for performing RF- based sensing is presented. The method comprises the steps: performing RF -based sensing in a first sensing area for detecting a first sensing event by a first group of nodes including at least two of the multiple nodes, and determining a second sensing event detection performance for performing RF- based sensing in the first sensing area for detecting the first sensing event by the first group together with an additional node or by the first group with one of the nodes of the first group removed from the first group.

The method may comprise one or more of the steps: adding the additional node to the first group in dependence of the second sensing event detection performance, removing the one of the nodes of the first group from the first group in dependence of the second sensing event detection performance.

Additionally, or alternatively, the method may comprise one or more of the steps: determining a first sensing event detection performance for performing RF- based sensing in the first sensing area for detecting the first sensing event by the first group, adjusting a setting of configuration parameters of one or more of the nodes of the first group based on capabilities of the additional node, capabilities of one or more of the nodes of the first group, or capabilities of the additional node and one or more of the nodes of the first group in order to optimize the second sensing event detection performance, adjusting a setting of configuration parameters of the additional node based on capabilities of the additional node, capabilities of one or more of the nodes of the first group, or capabilities of the additional node and one or more of the nodes of the first group in order to optimize the second sensing event detection performance, determining the second sensing event detection performance based on one or more of the following sensing event detection performance parameters:

- a similarity of the additional node or the one of the nodes of the first group to the one or more of the nodes of the first group,

- a batch to which the additional node or the one of the nodes of the first group belongs,

- a contribution of the additional node or the one of the nodes of the first group to an overall baseline of the first group, - capabilities of the additional node or the one of the nodes of the first group,

- one or more node characteristics of the additional node or the one of the nodes of the first group relevant for performing RF-based sensing,

- an amount of noise received or transmitted by the additional node or the one of the nodes of the first group,

- a setting of configuration parameters of the additional node or the one of the nodes of the first group, determining the similarity of the additional node to the one or more of the nodes of the first group based on one or more similarity criteria, determining the similarity of the one of the nodes of the first group to the one or more of the nodes of the first group based on one or more similarity criteria, determining whether the additional node fulfills the one or more similarity criteria with the one or more of the nodes of the first group in order to determine the similarity of the additional node to the one or more of the nodes of the first group, determining whether the one of the nodes of the first group fulfills the one or more similarity criteria with the one or more of the nodes of the first group in order to determine the similarity of the one of the nodes of the first group to the one or more of the nodes of the first group, adjusting the setting of the configuration parameters of the additional node based on its similarity to the one or more of the other nodes of the first group, adjusting the setting of the configuration parameters of the one of the nodes of the first group based on its similarity to the one or more of the other nodes of the first group, determining the second sensing event detection performance during a stable operational state of the additional node, determining the second sensing event detection performance during a changing operational state of the additional node, determining the second sensing event detection performance during a stable operational state of the one of the nodes of the first group, determining the second sensing event detection performance during a changing operational state of the one of the nodes of the first group, performing RF-based sensing in a second sensing area for detecting a second sensing event by a second group of nodes including at least two of the multiple nodes that are not included in the first group, determining a third sensing event detection performance for performing RF- based sensing in the second sensing area for detecting the second sensing event by the second group, determining a fourth sensing event detection performance for performing RF- based sensing in the second sensing area for detecting the second sensing event by the second group together with the additional node, determining the fourth sensing event detection performance for performing RF -based sensing in the second sensing area for detecting the second sensing event by the second group with one of the nodes of the second group removed from the second group, optimizing an allocation of the additional node to the first group and the second group based on the determined sensing event detection performances, optimizing an allocation of the one of the nodes of the first group to the first group and the second group based on the determined sensing event detection performances, optimizing an allocation of the one of the nodes of the second group to the first group and the second group based on the determined sensing event detection performances, optimizing the allocation of the additional node to the first group and the second group additionally based on a respective sensing application performed by the first group and a respective sensing application performed by the second group, optimizing the allocation of the one of the nodes of the first group to the first group and the second group additionally based on the respective sensing application performed by the first group and the respective sensing application performed by the second group, optimizing the allocation of the one of the nodes of the second group to the first group and the second group additionally based on the respective sensing application performed by the first group and the respective sensing application performed by the second group.

Adjusting the setting of the configuration parameters of one or more of the nodes of the first group may include adjusting the setting of the configuration parameters of, for example, the one of the nodes of the first group, of one or more nodes of the first group other than the one of the nodes of the first group, of two or more nodes of the first group, or of all of the nodes of the first group.

The method may, for example, include the step: adjusting the setting of the configuration parameters of the one of the nodes of the first group based on capabilities of the one of the nodes of the first group, capabilities of the other nodes of the first group, or capabilities of the nodes of the first group in order to optimize the second sensing event detection performance.

The setting of the configuration parameters adjusted may for example be a location of the additional node relative to the nodes of the first group or of the one of the nodes of the first group relative to the other nodes of the first group.

In a further aspect of the present invention a computer program product for performing RF-based sensing in an RF system comprising multiple nodes at different locations for performing RF-based sensing is presented. The computer program product comprises program code means for causing a processor to carry out the method according to at least one of the claims 12 to 14 or any embodiment of the method, when the computer program product is run on the processor.

In a further aspect a computer readable medium having stored the computer program product of claim 15 is presented. Alternatively or additionally the computer readable medium can have the computer program product according to any embodiment of the computer program product stored.

It shall be understood that the RF system of claim 1, the method of claim 12, the computer program product of claim 15, and the computer readable medium have similar and/or identical preferred embodiments, in particular, as defined in the dependent claims.

It shall be understood that a preferred embodiment of the present invention can also be any combination of the dependent claims or above embodiments with the respective independent claim.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following drawings:

Fig. 1 shows schematically and exemplarily an RF system comprising multiple nodes at different locations for performing RF-based sensing with an additional node not allocated to any of a first group and a second group of nodes,

Fig. 2 shows schematically and exemplarily the RF system shown in Fig. 1 with an allocation in which the additional node is added to the first group,

Fig. 3 shows schematically and exemplarily the RF system shown in Fig. 2 with an allocation in which a node of the first group is removed, Fig. 4 shows schematically and exemplarily the RF system shown in Fig. 3 with an allocation in which the previously removed node of the first group is added to the second group, and

Fig. 5 shows schematically and exemplarily an embodiment of a method for performing RF-based sensing in an RF system comprising multiple nodes at different locations for performing RF-based sensing.

DETAILED DESCRIPTION OF EMBODIMENTS

Fig. 1 shows schematically and exemplarily an RF system in form of a connected lighting (CL) system 100. The CL system 100 comprises nodes 10, 12, 14, 16, 18, and 20 arranged at different locations for performing RF-based sensing. In other embodiments the RF system may also include a different number of nodes, e.g., less nodes, such as two, or more nodes, such as seven nodes.

Besides performing RF-based sensing, the nodes 10 to 20 perform further tasks. Node 10 is a bridge comprising a memory 22, a processor 24, and a transceiver unit 26 including different transceivers and an antenna array (not shown).

The memory 22 stores a computer program product for performing RF-based sensing in an RF system comprising multiple nodes at different locations for performing RF- based sensing, such as the CL system 100. The computer program product comprises program code means for causing the processor 24 to carry out, for example, the method for performing RF-based sensing described with respect to Fig. 5, when the computer program product is run on the processor 24. The memory 22, furthermore, comprises algorithms for controlling the nodes 12 to 20 of the CL system 100.

The transceiver unit 26 is used for performing data communication with the other nodes of the CL system 100. Node 10 receives sensing signals and status information signals from the other nodes 12 to 20 of the CL system 100 and provides control signals to the other nodes 12 to 20 of the CL system 100 for controlling them. Furthermore, the transceiver unit 26 is used for performing data communication with an external server 200. The external server 200 can provide control signals to the node 10 in order to control the RF system 100. The transceiver unit may include, for example, two transceivers, one for data communication with the nodes of the CL system, e.g., a Zigbee transceiver, and another one for data communication with the external server, e.g., a Wi-Fi transceiver. In other embodiments, the external server may be an internal server instead or a remote control included in the RF system for controlling the RF system. The nodes 12, 14, 16, and 18 are luminaires for providing light. The node 20 is a temperature sensor which measures a room temperature. In other embodiments, the RF system may have a different number of nodes arranged at different locations, the nodes including, for example, routers, bridges, lights, luminaires, HVAC devices, plugs, switches, or sensors.

The wireless infrastructure of the CL system 100 can be used for performing their standard tasks as well as for performing RF -based sensing, thus increasing the functionality of the CL system 100. RF -based sensing can, for example, be used for motion detection, presence detection, people counting, breathing rate measurements, heart rate measurements, shape detection, activity recognition, gesture recognition, fall detection, or for performing other sensing applications.

In this embodiment, the nodes 12 and 14 form a first group 28 of nodes for performing RF-based sensing in a first sensing area 30 for detecting a first sensing event. In this embodiment, the locations of the nodes 12 and 14 of the first group 28 define the size and location of the first sensing area 30. Nodes 16 and 18 form a second group 32 of nodes for performing RF-based sensing in a second sensing area 34 for detecting a second sensing event. The locations of the nodes 16 and 18 of the second group 32 define the size and location of the second sensing area 32. In other embodiments, the first sensing area and the second sensing area may also be predetermined areas, e.g., each defined by a location and size of a room or specific volume in the room in which the respective group performs the RF- based sensing for detecting the respective sensing event.

In this embodiment, the first sensing event and the second sensing event are identical, namely detecting a motion of a user. In other embodiments, the first sensing event and the second sensing event may also be different sensing events, e.g., the first sensing event may be detecting presence of a user and the second sensing event may be recognizing an activity of a user.

In this embodiment, the nodes 12, 14, and 20 are arranged in an entrance hall 36. Nodes 16 and 18 are arranged in a living room 38. Node 10 is arranged in a utility room 40.

Fig. 1 shows a situation, in which node 20 is an additional node that has not been allocated to any of the groups 28 or 32 yet. Node 10 serves to control the nodes 12, 14, 16, 18, and 20.

In the following it is described how the CL system 100 optimizes an allocation of the nodes 12 to 20 to the first group 28 and the second group 32 of the CL system 100. In other embodiments, the RF system may also include more groups and more nodes and may perform a corresponding method for allocating the nodes to different groups in order to optimize a sensing event detection performance of the respective groups and/or the RF system.

In this embodiment, the CL system 100 optimizes the allocation of the nodes 12 to 20 to the first and second groups 28 and 32 when an additional node is added to the CL system 100. In other embodiments, other events may be considered for optimizing the allocation, such as optimizing the allocation in certain time intervals. In this embodiment, node 20 is added as the additional node to the CL system 100. Node 10 is special in that it is not considered for the allocation to the groups as it controls the other nodes. In other embodiments, also a node performing control functions may be added to the groups. Node 10 may also perform RF-based sensing, e.g., in the utility room 40.

The CL system 100 performs RF-based sensing in the first sensing area 30 by the first group 28 for detecting the first sensing event and determines a first sensing event detection performance. The CL system 100, furthermore, performs RF-based sensing in the second sensing area 34 by the second group 32 for detecting the second sensing event and determines a third sensing event detection performance. In this embodiment, the first sensing event detection performance and the second sensing event detection performance correspond to a respective probability that the respective sensing event has been correctly detected. In other embodiments, different criteria may be considered for determining the sensing event detection performance. Other criteria may include whether RF signals represent patterns that can be distinguished from noise and/or mapped to expected variations depending on features of interest. For example, if there is a lot of noise in the RF signals, the sensing event detection performance is bad as the sensing event cannot be reliably determined. If the RF signal does not have noise, but also does not show any periodic pattern, e.g., in a breathing detection pattern, then the sensing event detection performance is also bad because some repeating patterns are expected in the RF signals.

The CL system 100 then performs RF-based sensing in the first sensing area 30 for detecting the first sensing event by the first group 28 together with the additional node 20 and determines a second sensing event detection performance. Additionally, the CL system 100 performs RF-based sensing in the second sensing area 34 for detecting the second sensing event by the second group 32 together with the additional node 20 and determines a fourth sensing event detection performance. In other embodiments, the CL system 100 may also be configured for predicting the sensing event detection performances without performing RF-based sensing of the respective group together with the additional node.

In order to optimize the second sensing event detection performance and the fourth sensing event detection performance, the CL system 100 adjusts a setting of configuration parameters of the additional node 20 based on its capabilities as well as the capabilities of the nodes 12 and 14, respectively, 16 and 18 to which the additional node may be added. In this embodiment, the configuration parameters include a communication protocol used by the nodes, e.g., Zigbee, as well as frequency channels used for the RF-based sensing. In other embodiments, further configuration parameters, e.g., a location of the additional node, may be adjusted. In yet other embodiments, the RF system may be configured for adjusting the setting of the configuration parameters of the additional node or one or more of the nodes of the group to which the additional node may be added based on capabilities of the additional node, capabilities of one or more of the nodes of the group to which the additional node may be added, or capabilities of the additional node and one or more of the nodes of the group to which the additional node may be added in order to optimize the sensing event detection performance of the group together with the additional node. The RF system may also adjust the configuration parameters of the additional node and one or more of the nodes of the group to which the additional node may be added.

The RF-based sensing is performed with the optimized sensing event detection performances in order to determine whether adding the additional node 20 to one of the groups 28 or 32 improves the sensing event detection performance. Therefore, the sensing event detection performances are compared to each other and the highest sensing event detection performance is determined.

In this case the second sensing event detection performance is better than the first, third, and fourth sensing event detection performances. Therefore, the CL system 100 adds the additional node 20 to the first group 28 (cf. Fig. 2), i.e., the additional node is added to the first group in dependence of the second sensing event detection performance. If the second sensing event detection performance was worse than the first sensing event detection performance, the additional node 20 would not be added to the first group 28.

When the additional node 20 is added to the first group 28, the first sensing area 30 is adjusted accordingly. In other embodiments, the sensing areas may also be predetermined, e.g., fixed areas associated to a certain room. In order to further optimize the allocation of the nodes 12 to 20 in the CL system 100, the CL system 100 determines, whether removing one of the nodes from the groups 28 and 32 improves the sensing event detection performances.

Fig. 3 shows a situation in which the node 14 is removed from the first group 28. In this case, the first and second sensing event detection performances for the first group 28 are determined by performing RF-based sensing by the first group 28 as shown in Fig. 2 and by the first group 28 with node 14 removed from the first group 28. The sensing event detection performances are compared and in this case it is determined that the first sensing event detection performance, i.e., the sensing event detection performance of the first group 28 when the node 14 is included in the first group 28 is worse than the second sensing event detection performance, i.e., the sensing event detection performance when node 14 is removed from the first group 28. Therefore, node 14 is removed from the first group 28. This allows removing one of the nodes of the first group from the first group in dependence of the second sensing event detection performance.

The CL system 100 may perform equivalent steps as performed for the additional node 20 as described with respect to Fig. 1 for the node 14, e.g., adjusting its setting of configuration parameters in order to optimize the respective sensing event detection performance.

Fig. 4 shows a situation in which the node 14 previously removed from the first group 28 is now added to the second group 32. In this case, the node 14 serves as an additional node for the second group 32. The third and fourth sensing event detection performances for the second group 32 are determined by performing RF-based sensing by the second group 32 as shown in Fig. 3 and by the second group 32 together with the node 14. The sensing event detection performances are compared and in this case it is determined that the fourth sensing event detection performance, i.e., the sensing event detection performance of the second group 32 together with the node 14 is better than the third sensing event detection performance, i.e., the sensing event detection performance of the second group 32. Therefore, node 14 is added to the second group 28 and the second sensing area 34 is adapted accordingly. While the node 20 of the first group 28 is within the second sensing area 34, it is not included in the second group 32.

In other embodiments, the RF system may optimize the allocation of further nodes to the first group and the second group based on the determined sensing event detection performances. The allocation of the nodes to the groups may, for example, be additionally based on a respective sensing application performed by the respective group. Furthermore, the RF system may be configured for determining the sensing event detection performances during a stable operational state, e.g., during a stable temperature, as well as during a changing operational state of the additional node or the one of the nodes of the group which may be removed, e.g., during a temperature change. Potential defects or drops in sensing event detection performance may only be noticeable when the nodes change its operational state or transitions between two operational states. For example, due to manufacturing issues some solder joints may not be stable. In a stable operational state, this may not be an issue. But it may lead to an expansion or contraction of electronic components, such as the PCB of the node during thermal swings. These may later on translate into more noise in the RF signals, e.g., due to RF front-end components. For example, if the node is a luminaire, its sensing event detection performance may be good in a stable operational state, e.g., the luminaire has not provided light for a certain time or continuously provided light for a certain time. For a stable operational state, the node will therefore not negatively affect the sensing event detection performance of the group in which the node may be included. However, if the node changes its operational state, e.g., the luminaire is activated to provide light from an inactive state, the sensing event detection performance may be reduced. If, for example, the node is in a group in which the luminaire is regularly activated and deactivated, e.g., turning on and off the lights, such as in a hallway, there is an increased risk that due to activity and frequently turning on and off that luminaire, more noise is introduced by the luminaire due to settling times than in the stable situation. In this case, the luminaire, should not be added to the group for performing RF -based sensing. The luminaire, on the other hand may be used if it is arranged at a different location, e.g., in another room in which it is not regularly activated and deactivated, such as in a living room for burglar detection. In this case, the luminaire, for example, provides no lighting if a burglar is detected, but instead provides a signal to the user of the RF system.

In yet other embodiments, the RF system may instead of performing RF-based sensing by the groups together with the additional node or with one of the nodes removed from the respective groups, estimate or predict the second sensing event detection performance upfront. In this case, the RF system may be configured for determining the second sensing event detection performance based on one or more of the following sensing event detection performance parameters: a similarity of the additional node or the one of the nodes of the first group to one or more of the nodes of the first group, a batch to which the additional node or the one of the nodes of the first group belongs, a contribution of the additional node or the one of the nodes of the first group to an overall baseline of the first group, capabilities of the additional node or the one of the nodes of the first group, one or more node characteristics of the additional node or the one of the nodes of the first group relevant for performing radio frequency based sensing, an amount of noise received or transmitted by the additional node or the one of the nodes of the first group, and a setting of configuration parameters of the additional node or the one of the nodes of the first group.

The RF system may be configured for determining the similarity of the additional node or the one of the nodes of the first group to one or more of the nodes of the first group based on one or more similarity criteria. The similarity criteria may include one or more of a same batch to which the nodes belong, similar node characteristics relevant for performing radio frequency based sensing, similar environmental influences the nodes experienced, similar total operating times of the nodes, similar capabilities of the nodes, similar types of the nodes, similar settings of configuration parameters of the nodes, and similar baselines of the nodes.

The RF system may further be configured for adjusting a setting of configuration parameters of the additional node or the one of the nodes of the first group based on its similarity to the one or more of the other nodes of the first group.

In the following further embodiments are described.

The RF system may, for example, be configured for adding an additional node to one of the groups if there are no negative reports about a batch to which the additional node belongs. The RF system may automatically add the additional to a respective group or may suggest the user to add the node to the group manually via an interface. In case that similar nodes originating from the same batch have had RF sensing related issues in the past, the RF system might decide to not add the additional node or suggest to the user to not add it to any of the groups for performing RF-based sensing. The additional node may still perform other tasks, such as providing lighting, if it is a luminaire.

In case the user chooses to manually add the additional node to a respective group, the RF system may be configured for recommending to the user to not add the additional node and for providing information to the user what potential issues this may cause.

The RF system may be configured for weighing benefits of adding the additional node to the respective group and potential disadvantages or issues of performing RF-based sensing by the additional node together with the group.

The RF system may further be configured for applying modifications to the performance of the additional node that has been identified to have potential RF sensing related issues, such that the additional node may contribute most effectively or at least with lowest negative effect to the group to which it is added. For example, a setting of the additional node may be adjusted accordingly.

The RF system may additionally be configured for suggesting the user to physically exchange a first node located at a first location, which is known to have RF sensing related issues, for performing RF -based sensing, with a second node at a second location, which is known to have no RF sensing related issues. The second node may then be added to the group performing RF-based sensing in a first sensing area at the first location. RF -based sensing may in this case, for example, be performed only at the first location, i.e., by the group together with the second node such that no issues of the first node negatively influence the RF-based sensing.

In another embodiment, a setting of the configuration parameters may be adjusted of one or more of the nodes of a group and/or an additional node. This may include, for example, artificially adjusting signal metrics received from a respective node by other nodes. For example, if it is known that the respective node belongs to a specific batch that has gone through an undesired temperature swing during transport which affects sensing event detection performance due to micro-cracks in a PCB antenna of the node, the respective node may transmit at a lower transmit power than it is originally configured to. All other nodes may add an offset to what they received from this respective node for compensating for this issue. The offset may be, for example, a constant value or a temperature dependent value, depending on the temperature of the respective node. The temperature may be measured, for example, by the respective node and reported to the other nodes by the respective node. The temperature may also be estimated by another node, such as a temperature sensor. The temperature, may also, for example, be estimated based on a history of a brightness of the respective node, if it is a luminaire providing light.

The respective node may also adjust the signals it receives from other nodes, in case that its reception capability is affected, e.g., due to the micro-cracks in its PCB antenna.

The RF system may also control the node such that the node performs an additional pre-filtering to the signals it receives in case that these include a larger amount of noise than normal. For example, the respective node may perform 3-element moving window filtering when signals are received from other nodes at 1/3 of a usual rate.

In one further embodiment, a group performing RF-based sensing in a sensing area has 3 nodes of which one is known to have RF sensing related issues. However, performing RF-based sensing with 3 nodes has a higher sensing event detection performance than performing RF-based sensing with 2 nodes. When an additional node is added to the RF system, the node with RF sensing related issues may be replaced by the additional node in the group and RF-sensing with 3 nodes may be performed without the node known to have RF sensing related issues with an improved sensing event detection performance.

In another embodiment, the sensing event detection performance of the nodes may be determined, for example, as either Good or Bad. A node is defined as Good if it has signal variations above a first RF-based sensing threshold and a packet loss smaller than a second RF-based sensing threshold. The node is defined as Bad if it has signal variations below a first RF-based sensing threshold and a packet loss larger than a second RF-based sensing threshold. The RF system includes, for example, 9 nodes in form of luminaires A to I which are divided into three groups 1 to 3 which perform RF-based sensing in three areas 1 to 3, e.g., a living room, a bath room, and an office room. The following table shows an exemplary allocation of the nodes to the three groups 1 to 3:

The sensing event detection performance of group 3 may be improved by swapping the bad node I with one of the good nodes A, B, or C. This allows to provide all groups with a same number of good and bad nodes and may improve RF-based sensing for the RF system as a whole when reducing the sensing event detection performance of group 1 while increasing the sensing event detection performance of group 3 is overall beneficial. Swapping may be performed by a user or automatically by the RF system. For example, the location of the node I may be changed with the location of node C and the grouping may be updated accordingly. If the areas are overlapping, such as in a large office space, a change of the location of the nodes I and C may not be required. Swapping corresponds to removing node I from group 3 and node C from group 1 and adding node C to group 3 and node I to group 1. The following table shows an updated allocation of the nodes to the three groups 1 to 3 after swapping nodes C and I:

The swapping may take into account additional factors in order to optimize the sensing event detection performance of the RF system. The additional factors may include characteristics, for example, configuration parameters or properties of the nodes, e.g., if the nodes are luminaires or lights, a different allocation may be made if both are color Al 9 bulbs compared to if they are both Al 9 bulbs but one is a color Al 9 bulb and the other one a white A19 bulb, or if one is A19 and the other is a lightstrip. Further characteristics may include, for example, a total operational time of the nodes, such as running and burning hours of the nodes. These are associated to, for example, aging effects of the electronics. For example, nodes with similar running and burning hours may be allocated to the same group for performing RF-based sensing. The characteristics may also include a relative location of the node to the other nodes of the group to which the node may be added or from which the node may be removed. Some sensing areas may be better for detecting disturbances caused by people than other areas. Preferably, the nodes with best sensing event detection performance should be arranged in these locations and added to the respective group that performs RF- based sensing in these sensing areas. Similarly, sensing areas requiring a very small occupancy detection latency, e.g., an entrance hall of a building may preferably be equipped with a group of nodes having superior sensing event detection performance.

The additional factors may also include, for example, an amount of reconfiguration needed for optimizing the sensing event detection performance. The amount of reconfiguration needed may also involve reconfiguration by the user, e.g., if there are two possible locations at which the node may perform RF-based sensing. The RF system may be configured for selecting to add the node to a group in which fewest reconfiguration of a setting of configuration parameters of the node are needed, such as lighting scenes, automations, etc. or which requires the least physical effort, such as, preferring a location which does not require to climb a ladder and disassemble a luminaire holding the bulb.

In other embodiments, having a reduced sensing event detection performance in some sensing areas may be sufficient for performing a respective sensing application. This may allow to allocate nodes to groups in which they are needed in order to perform other sensing applications with an improved sensing event detection performance. For example, a sensing event detection performance with fewer good nodes may be acceptable for the user and a sensing event detection performance of more bad nodes may also be ok. A possible allocation in this situation may be as presented in the following table:

In this case, group 1 has only two good nodes A and B, which is sufficient for the sensing application performed by group 1, e.g., performing presence sensing in a small entry hallway. Group 3 has in total more bad nodes but they all contribute or compensate one another sufficiently such that group 3 can perform motion sensing in a kitchen which gets little utilization over time. A risk of false negatives is low since people are always moving a lot within the kitchen and false positives are less of a concern since the user does not directly see the nodes, e.g., in form of lights, from most other rooms.

Fig. 5 shows an embodiment of the method 500 for performing RF-based sensing in an RF system comprising multiple nodes at different locations for performing RF- based sensing. The method can, for example, be used by the CL system 100 disclosed in Figs. 1 to 4. The method may allow optimizing an allocation of nodes to different groups in the CL system 100 in order to optimize a sensing event detection performance.

In step 502, RF-based sensing is performed in a first sensing area for detecting a first sensing event by a first group of nodes including at least two of the multiple nodes and a corresponding first sensing event detection performance is determined.

In step 504, RF-based sensing is performed in the first sensing area for detecting the first sensing event by the first group of nodes together with an additional node and a corresponding second sensing event detection performance is determined. Alternatively, RF-based sensing may be performed in the first sensing area for detecting the first sensing event by the first group with one of the nodes of the first group removed from the first group.

In step 506, the second sensing event detection performance and the first sensing event detection performance are compared in order to determine whether the additional node shall be added to the first group or not. Alternatively, it may be determined whether the one of the nodes of the first group shall be removed from the first group or not.

In step 508, the additional node is added to the first group if the second sensing event detection performance is better than the first sensing event detection performance and not added to the first group if it is worse. In other embodiments, additional node may also be added in dependence of the second sensing event detection performance in any other manner. Alternatively, the one of the nodes of the first group may be removed from the first group if the second sensing event detection performance is better than the first sensing event detection performance.

In other embodiments, the method may optimize the allocation of more nodes to more groups, e.g., an additional node, one of the nodes of the first group, and one of at least two nodes of a second group to the first group and the second group. The nodes may be added, replaced, removed, or swapped in order to optimize their allocation to the groups based on respective sensing event detection performances. Settings of configuration parameters of the nodes may be adjusted based on capabilities of other nodes in order to optimize the respective sensing event detection performances.

In other embodiments, the sensing event detection performances may be estimated upfront, i.e., without performing the RF-based sensing, for the first group together with the additional node or for the first group with the one of the nodes removed from the first group, based on one or more sensing event detection performance parameters, such as, a similarity of node to be added or removed with the nodes of the group, or the like. This allows to estimate, whether the sensing event detection performance will be improved or reduced by adding an additional node to the group, respectively removing a respective node of the group from the group. The similarity between the nodes may be determined based on one or more similarity criteria.

A setting of the configuration parameters of the nodes may also be adjusted based on the similarity between the nodes.

The sensing event detection performances may be determined during a stable operation of the nodes and/or during a changing operation of the nodes.

The allocation of the nodes may furthermore depend on the respective sensing applications performed by the respective groups.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. For example, it is possible to operate the invention in an embodiment wherein the nodes are HVAC devices and the RF system is a HVAC system or a building management system (BMS).

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

In the claims, the word “comprising” and “including” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality.

A single unit, processor, or device may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Operations like performing RF-based sensing in a first sensing area for detecting a first sensing event by a first group of nodes including at least two of the multiple nodes, determining a second sensing event detection performance for performing RF-based sensing in the first sensing area for detecting the first sensing event by the first group together with an additional node or by the first group with one of the nodes of the first group removed from the first group, adding the additional node to the first group in dependence of the second sensing event detection performance, removing the one of the nodes of the first group from the first group in dependence of the second sensing event detection performance, et cetera performed by one or several units or devices can be performed by any other number of units or devices. These operations and/or the method can be implemented as program code means of a computer program and/or as dedicated hardware.

A computer program product may be stored/distributed on a suitable medium, such as an optical storage medium, or a solid-state medium, supplied 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 telecommunication systems.

Any reference signs in the claims should not be construed as limiting the scope.

The present invention relates to RF-based sensing in an RF system comprising multiple nodes at different locations. At least two of the multiple nodes form a first group of nodes that performs RF-based sensing in a first sensing area for detecting a first sensing event. A second sensing event detection performance for performing RF-based sensing in the first sensing area for detecting the first sensing event by the first group together with an additional node or by the first group with one of the nodes of the first group removed from the first group is determined. The second sensing event detection performance can be compared to a first sensing event detection performance for performing RF-based sensing by the first group. Based on the comparison it may be decided whether to remove or add a respective node.

Claims

33 CLAIMS:

1. A radio frequency system (100) comprising multiple nodes (10, 12, 14, 16, 18, 20) at different locations for performing radio frequency based sensing, wherein at least two of the multiple nodes (12, 14) form a first group (28) of nodes that is configured for performing radio frequency based sensing in a first sensing area (30) for detecting a first sensing event, and wherein the radio frequency system (100) is configured for determining a second sensing event detection performance for performing radio frequency based sensing in the first sensing area (30) for detecting the first sensing event by the first group (28) together with an additional node (20) or by the first group (28) with one of the nodes (14) of the first group (28) removed from the first group (28); wherein the radio frequency system (100) is configured for determining the second sensing event detection performance based on the following sensing event detection performance parameter: a similarity of the additional node (20) or the one of the nodes (14) of the first group (28) to one or more of the nodes (12, 14) of the first group (28), and wherein the radio frequency system (100) is configured for determining the similarity of the additional node (20) or the one of the nodes (14) of the first group (28) to one or more of the nodes (12, 14) of the first group (28) based on one or more similarity criteria.

2. The radio frequency system (100) according to claim 1, wherein the radio frequency system (100) is configured for adjusting a setting of configuration parameters of one or more of the nodes (12, 14) of the first group (28), the additional node (20), or one or more of the nodes (12, 14) of the first group (28) and the additional node (20) based on capabilities of the additional node (20), capabilities of one or more of the nodes (12, 14) of the first group (28), or capabilities of the additional node (20) and one or more of the nodes (12, 14) of the first group (28) in order to optimize the second sensing event detection performance. 34

3. The radio frequency system (100) according to claim 1 or 2, wherein the radio frequency system (100) is configured for adding the additional node (20) to the first group (28) in dependence of the second sensing event detection performance, for removing the one of the nodes (14) of the first group (28) from the first group (28) in dependence of the second sensing event detection performance, or for adding the additional node (20) to the first group (28) and for removing the one of the nodes (14) of the first group (28) from the first group (28) in dependence of the second sensing event detection performance.

4. The radio frequency system (100) according to at least one of the claims 1 to 3, wherein the radio frequency system (100) is configured for determining the second sensing event detection performance based on one or more of the following sensing event detection performance parameters: a batch to which the additional node (20) or the one of the nodes (14) of the first group (28) belongs, a contribution of the additional node (20) or the one of the nodes (14) of the first group (28) to an overall baseline of the first group (28), capabilities of the additional node (20) or the one of the nodes (14) of the first group (28), one or more node characteristics of the additional node (20) or the one of the nodes (14) of the first group (28) relevant for performing radio frequency based sensing, an amount of noise received or transmitted by the additional node (20) or the one of the nodes (14) of the first group (28), a setting of configuration parameters of the additional node (20) or the one of the nodes (14) of the first group (28).

5. The radio frequency system (100) according to claim 4, wherein the similarity criteria include one or more of a same batch to which the nodes (12, 14, 20) belong, similar node characteristics relevant for performing radio frequency based sensing, similar environmental influences the nodes (12, 14, 20) experienced, similar total operating times of the nodes (12, 14, 20), similar capabilities of the nodes (12, 14, 20), similar types of the nodes (12, 14, 20), similar settings of configuration parameters of the nodes (12, 14, 20), and similar baselines of the nodes (12, 14, 20).

6. The radio frequency system (100) according to at least one of the claims 1 to

5, wherein the radio frequency system (100) is configured for adjusting a setting of configuration parameters of the additional node (20) or the one of the nodes (14) of the first group (28) based on its similarity to the one or more of the other nodes (12, 14) of the first group (28).

7. The radio frequency system (100) according to at least one of the claims 1 to

6, wherein the radio frequency system (100) is configured for determining the second sensing event detection performance during a stable operational state and during a changing operational state of the additional node (20) or the one of the nodes (14) of the first group (28).

8. The radio frequency system (100) according to at least one of the claims 1 to

7, wherein at least two of the multiple nodes (16, 18) that are not included in the first group (28) form a second group (32) of nodes that is configured for performing radio frequency based sensing in a second sensing area (34) for detecting a second sensing event, and wherein the radio frequency system (100) is configured for determining a fourth sensing event detection performance for performing radio frequency based sensing in the second sensing area (34) for detecting the second sensing event by the second group (32) together with the additional node (20) or by the second group (32) with one of the nodes (18) of the second group (32) removed from the second group (32).

9. The radio frequency system (100) according to claim 8, wherein the radio frequency system (100) is configured for optimizing an allocation of the additional node (20), the one of the nodes (14) of the first group (28), and/or the one of the nodes (18) of the second group (32) to the first group (28) and the second group (32) based on the determined sensing event detection performances.

10. The radio frequency system (100) according to claim 9, wherein the radio frequency system (100) is configured for optimizing the allocation of the additional node (20), the one of the nodes (14) of the first group (28), and/or the one of the nodes (18) of the second group (32) to the first group (28) and the second group (32) additionally based on a respective sensing application performed by the first group (28) and a respective sensing application performed by the second group (32).

11. A method for performing radio frequency based sensing in a radio frequency system (100) comprising multiple nodes (12, ... , 20) at different locations for performing radio frequency based sensing, the method comprising the steps: performing radio frequency based sensing in a first sensing area (30) for detecting a first sensing event by a first group (28) of nodes including at least two of the multiple nodes (12, 14), and determining a second sensing event detection performance for performing radio frequency based sensing in the first sensing area (30) for detecting the first sensing event by the first group (28) together with an additional node (20) or by the first group (28) with one of the nodes (14) of the first group (28) removed from the first group (28) wherein the method further comprises the step of: determining the second sensing event detection performance based on the following sensing event detection performance parameter: a similarity of the additional node (20) or the one of the nodes (14) of the first group (28) to one or more of the nodes (12, 14) of the first group (28), and wherein the method further comprises determining the similarity of the additional node (20) or the one of the nodes (14) of the first group (28) to one or more of the nodes (12, 14) of the first group (28) based on one or more similarity criteria.

12. The method according to claim 11, comprising one or more of the steps: adding the additional node (20) to the first group (28) in dependence of the second sensing event detection performance, removing the one of the nodes (14) of the first group (28) from the first group (28) in dependence of the second sensing event detection performance.

13. The method according to claim 11 or 12, comprising one or more of the steps: determining a first sensing event detection performance for performing radio 37 frequency based sensing in the first sensing area (30) for detecting the first sensing event by the first group (28), adjusting a setting of configuration parameters of one or more of the nodes (12, 14) of the first group (28) based on capabilities of the additional node (20), capabilities of one or more of the nodes (12, 14) of the first group (28), or capabilities of the additional node (20) and one or more of the nodes (12, 14) of the first group (28) in order to optimize the second sensing event detection performance, adjusting a setting of configuration parameters of the additional node (20) based on capabilities of the additional node (20), capabilities of one or more of the nodes (12, 14) of the first group (28), or capabilities of the additional node (20) and one or more of the nodes (12, 14) of the first group (28) in order to optimize the second sensing event detection performance, determining the second sensing event detection performance based on one or more of the following sensing event detection performance parameters: a batch to which the additional node (20) or the one of the nodes (14) of the first group (28) belongs, a contribution of the additional node (20) or the one of the nodes (14) of the first group (28) to an overall baseline of the first group (28), capabilities of the additional node (20) or the one of the nodes (14) of the first group (28), one or more node characteristics of the additional node (20) or the one of the nodes (14) of the first group (28) relevant for performing radio frequency based sensing, an amount of noise received or transmitted by the additional node (20) or the one of the nodes (14) of the first group (28), a setting of configuration parameters of the additional node (20) or the one of the nodes (14) of the first group (28), determining the similarity of the additional node (20) to the one or more of the nodes (12, 14) of the first group (28) based on one or more similarity criteria, determining the similarity of the one of the nodes (14) of the first group (28) to the one or more of the nodes (12) of the first group (28) based on one or more similarity criteria, determining whether the additional node (20) fulfills the one or more similarity criteria with the one or more of the nodes (12, 14) of the first group (28) in order to 38 determine the similarity of the additional node (20) to the one or more of the nodes (12, 14) of the first group (28), determining whether the one of the nodes (14) of the first group (28) fulfills the one or more similarity criteria with the one or more of the nodes (12) of the first group (28) in order to determine the similarity of the one of the nodes (14) of the first group (28) to the one or more of the nodes (12) of the first group (28), adjusting the setting of the configuration parameters of the additional node (20) based on its similarity to the one or more of the nodes (12, 14) of the first group (28), adjusting the setting of the configuration parameters of the one of the nodes (14) of the first group (28) based on its similarity to the one or more of the other nodes (12) of the first group (28), determining the second sensing event detection performance during a stable operational state of the additional node (20), determining the second sensing event detection performance during a changing operational state of the additional node (20), determining the second sensing event detection performance during a stable operational state of the one of the nodes (14) of the first group (28), determining the second sensing event detection performance during a changing operational state of the one of the nodes (14) of the first group (28), performing radio frequency based sensing in a second sensing area (34) for detecting a second sensing event by a second group (32) of nodes including at least two of the multiple nodes (16, 18) that are not included in the first group (28), determining a third sensing event detection performance for performing radio frequency based sensing in the second sensing area (34) for detecting the second sensing event by the second group (32), determining a fourth sensing event detection performance for performing radio frequency based sensing in the second sensing area for detecting the second sensing event by the second group (32) together with the additional node (20), determining the fourth sensing event detection performance for performing radio frequency based sensing in the second sensing area for detecting the second sensing event by the second group (32) with one of the nodes (18) of the second group (32) removed from the second group (32), optimizing an allocation of the additional node (20) to the first group (28) and the second group (32) based on the determined sensing event detection performances, 39 optimizing an allocation of the one of the nodes (14) of the first group (28) to the first group (28) and the second group (32) based on the determined sensing event detection performances, optimizing an allocation of the one of the nodes (18) of the second group (32) to the first group (28) and the second group (32) based on the determined sensing event detection performances, optimizing the allocation of the additional node (20) to the first group (28) and the second group (32) additionally based on a respective sensing application performed by the first group (28) and a respective sensing application performed by the second group (32), optimizing the allocation of the one of the nodes (14) of the first group (28) to the first group (28) and the second group (32) additionally based on the respective sensing application performed by the first group (28) and the respective sensing application performed by the second group (32), optimizing the allocation of the one of the nodes (18) of the second group (32) to the first group (28) and the second group (32) additionally based on the respective sensing application performed by the first group (28) and the respective sensing application performed by the second group (32).

14. A computer program product for performing radio frequency based sensing in a radio frequency system (100) comprising multiple nodes (10, ... , 20) at different locations for performing radio frequency based sensing, wherein the computer program product comprises program code means for causing a processor (24) to carry out the method according to at least one of the claims 11 to 13, when the computer program product is run on the processor (24).