Method for improving RF-based atmospheric condition detection and RF-based network communication

Abstract

A method for selecting a subset of devices from multiple devices in a wireless network to perform the following: a first function, including transmitting, receiving, and / or processing a first radio frequency signal in a first frequency band for detecting atmospheric conditions; and a second function, including transmitting, receiving, and / or processing a second radio frequency signal in a second frequency band that at least partially overlaps with the first frequency band for performing network communication; wherein the first and second functions are performed during a time period; and wherein the time period includes a first subset of time slots and a second subset of time slots; wherein the method includes: selecting a subset of devices based on the physical location of the devices relative to the area to be monitored for atmospheric conditions; allocating the first subset of time slots to each selected device to perform the first function, wherein the first subset of time slots is allocated based on a priority value associated with the relative priority of performing the first function compared to the second function; allocating the second subset of time slots to each selected device to perform the second function; controlling the selected devices to perform the first function and the second function respectively during the allocated time slots.

Description

Technical Field

[0001] The present invention relates to a method, system, and computer program product for selecting a subset of devices from multiple devices in a wireless network to perform a first function and a second function. The first and second functions relate to detecting atmospheric conditions and performing network communication, respectively. Background Art

[0002] Connected lighting refers to a system of one or more lighting devices that are not (or not only) controlled by traditional wired, electrical switches, or dimmer circuits, but rather by using a data communication protocol via a wired or more commonly wireless connection (such as a wired or wireless network). These connected lighting networks form what is commonly referred to as the Internet of Things (IoT) or more specifically the Internet of Light (IoL). Typically, lighting devices or even individual lights within a lighting device can each be equipped with a wireless receiver or transceiver for receiving lighting control commands from a lighting control device according to a wireless networking protocol such as Zigbee, Wi-Fi, or Bluetooth.

[0003] Recent developments in wireless network technology have led to the development of highly reliable, low-cost, and high-performance radios that operate in a unique domain that was once the millimeter-wave band - the radio frequency (RF) spectrum band between 30 GHz and 300 GHz. The name "millimeter wave (mm wave)" stems from the fact that the wavelength range of this band is from approximately 10 mm to less than 1 mm. Although most of the millimeter-wave spectrum has been licensed, a portion around the 60 GHz spectrum is available for communication freely, which is now addressed by the standardization task force IEEE802.11ay.

[0004] Communication in many fields is moving towards mm waves in order to avoid the crowded 2.4 GHz and 5 GHz spectrums and to enable broadband communication. There are many interesting properties of mm waves, which, for example, not only make it possible to communicate at this frequency but also to measure air quality. Summary of the Invention

[0005] The inventors have recognized that both RF-based air quality measurement and RF-based network communication can be beneficially provided via the same devices in a wireless network. However, in order to prevent low-quality RF-based air quality measurement, the RF signals for air quality measurement should not be affected by any RF signals for network communication.

[0006] Accordingly, an object of the present invention is to optimize air quality measurement by allocating the spectrum for RF-based air quality measurement along a route including at least two (communication) devices instead of RF-based network communication occurring simultaneously along the same path.

[0007] According to a first aspect, this object is achieved by a method for selecting a subset of devices from multiple devices in a wireless network to perform the following: a first function, including transmitting, receiving, and / or processing a first radio frequency signal in a first frequency band for detecting atmospheric conditions; and a second function, including transmitting, receiving, and / or processing a second radio frequency signal in a second frequency band that at least partially overlaps with the first frequency band for performing network communication; wherein the first and second functions are performed during a time period; and wherein the time period includes a first subset of time slots and a second subset of time slots; wherein the method includes: selecting a subset of devices based on the physical location of the devices relative to the area where the atmospheric conditions are to be monitored; allocating the first subset of time slots to each selected device to perform the first function, wherein the first subset of time slots is allocated based on a priority value associated with the relative priority of performing the first function compared to the second function; allocating the second subset of time slots to each selected device to perform the second function; and controlling the selected devices to perform the first and second functions respectively during the allocated time slots.

[0008] The method includes selecting a subset of devices from multiple devices to perform a first function and a second function; wherein the first and second functions include transmitting, receiving, and / or processing first and second radio frequency signals (e.g., 60 GHz) in first and second frequency bands (e.g., mm-wave frequency band) for detecting atmospheric conditions and performing network communication respectively. The first and second functions can also be referred to as RF-based atmospheric condition detection and RF-based network communication respectively. The first and second frequency bands can at least partially overlap, e.g., the first and second functions can use the mm-wave frequency band for both detecting atmospheric conditions and performing network communication. The selection can be based on the physical location of the devices relative to the area where the atmospheric conditions are to be monitored. In addition, for each of the selected subset of devices, the time period for performing the two functions can be divided into a first subset of time slots and a second subset of time slots; and the first subset of time slots is allocated to the first function, and the second subset of time slots is allocated to the second function. Since for the selected subset of devices, based on the priority value, corresponding time slots are allocated to perform both RF-based air quality measurement (i.e., atmospheric condition detection) and network communication, the quality of the RF-based air quality measurement (atmospheric condition detection) is optimized instead of the RF-based network communication that occurs simultaneously along the same path. Atmospheric conditions can include the state of the atmosphere, e.g., in terms of detecting one or more of atmospheric pollutants, detecting gaseous substances in the air, measuring humidity, air moisture, etc., the conditions can include the state of the atmosphere. Other examples of defining atmospheric conditions known to those skilled in the art are not excluded.

[0009] According to an embodiment, the selected subset of devices can be further arranged to transmit information about the detected atmospheric conditions in the second subset of time slots; wherein the information is obtained in the first subset of time slots.

[0010] When a selected subset of devices is used to detect atmospheric conditions in a first time slot subset, information about the detected conditions (such as the amount of atmospheric pollutants detected in the atmosphere, the level of gaseous substances, etc.) can be transmitted in a second time slot subset. Thus, the selected subset can also advantageously use the time slots reserved for network communication to transmit information about the detected atmospheric conditions. The information can be obtained after processing the first signal. The information can be transmitted to a server and / or neighboring devices.

[0011] According to an embodiment, a priority value can be determined for each in the selected subset of devices based on the relative positions of the selected devices within the area to be monitored for atmospheric conditions.

[0012] Time slots are assigned to each in the selected subset of devices based on the priority values; wherein the priority values can be assigned based on the proximity of the selected devices to the area of interest. The relative positions of the selected devices can be relative to each other within the area. The relative positions of the selected devices can be relative to the area. The relative positions of the selected devices can be relative to the atmospheric conditions to be monitored. The priority value is associated with the relative priority of performing a first function compared to a second function. The priority value can be a vector of values, each value associated with performing a first function compared to a second function. The elements of the vector can be respectively associated with the selected subset of devices. The priority value can be between 0 and 1; for example, 0 indicates a low priority and 1 indicates a high priority. For example, a selected device included in the area can be assigned a relatively high priority value (such as 0.8) to perform a first function (RF-based atmospheric condition detection), and a smaller priority value (such as 0.2) to perform a second function (RF-based network communication). Similarly, the priority value can decrease or increase linearly or non-linearly as a function of the proximity of the selected device to the area. Thus, based on proximity, the selected device can spend less or more time on RF-based atmospheric condition detection.

[0013] According to an embodiment, the priority value can indicate communication traffic in a wireless network such that the allocation of the first time slot subset can be further based on the communication traffic in the wireless network.

[0014] The priority value can be based on the communication traffic in the wireless network. The priority value can be based on the network load in the wireless network. In one example, for a selected device with a relatively high communication load, the priority value can be assigned based on the communication load such that the selected device with a higher communication load can spend more time performing RF-based network communication.

[0015] According to an embodiment, the method can further include receiving an input in a subsequent time period; wherein the input can indicate tracking information of an atmospheric pollutant layer relative to the area.

[0016] The atmospheric pollutant layer can be an atmospheric pollutant cloud, such as an airborne toxin. The cloud may be moving from one area to another. Tracking information can include the location of the cloud, such as GPS coordinates. The tracking information can be received from a network external to the wireless network. Alternatively, it can be generated by the wireless network.

[0017] According to an embodiment, the method can further include modifying a selected subset of devices based on the received input.

[0018] When an input indicating tracking information of an atmospheric pollutant cloud is received in a subsequent time period, the spatial location of the atmospheric pollutant cloud can be different from its spatial location in a previous time period. The selected subset of devices can be modified based on the received input. For example, additional devices from multiple devices can be added to the selected subset based on their physical location relative to the atmospheric pollutant cloud. If one or more devices in the selected subset are no longer near the atmospheric pollutant cloud in a subsequent time period, the one or more selected devices can be removed from the selected subset.

[0019] According to an embodiment, the method can further include modifying a priority value based on the received input; and based on the modified priority value, allocating a first subset of time slots to each device in the selected subset of devices.

[0020] The priority value can be modified based on the received input. For example, based on the spatial location of the atmospheric pollutant cloud, the priority value can be modified while keeping the selected subset unchanged. For example, a selected device located in the atmospheric pollutant cloud region in a subsequent time period is assigned a higher priority value compared to when the selected device was not located in the region in a previous time period. By modifying the priority value and / or the selected subset of devices, the detection of a moving atmospheric pollutant cloud can be optimized.

[0021] According to an embodiment, the plurality of devices can include at least one lighting device; and wherein the light output of the at least one lighting device can be controlled via a second function.

[0022] In this advantageous embodiment, the plurality of devices can include at least one lighting device, such as an outdoor lighting device (such as a lamp post) or an indoor lighting device. In an outdoor environment, the infrastructure of the lamp post can be advantageously utilized to use RF-based atmospheric condition detection and RF-based network communication; wherein the RF-based network communication can be used to control the light output of the lamp post. For example, the RF-based network communication can be used to control one or more parameters of the at least one lighting device, such as the color, color temperature, intensity, beam width, beam direction, illumination intensity, and / or other parameters of one or more light sources.

[0023] According to an embodiment, the plurality of devices may include at least one aerial device; and wherein the at least one aerial device may be selected based on an elevation difference between the selected at least one aerial device and another selected subset of devices to detect atmospheric conditions above the another selected subset of devices.

[0024] Provided that, if the elevation of the area for which atmospheric conditions are to be monitored is higher compared to the elevation of the selected subset of devices, the aerial device may be used for RF-based atmospheric condition detection. For example, at least one of the selected subset of devices may be arranged to transmit mm waves, and the at least one aerial device may be arranged to receive and / or process mm wave signals for RF-based atmospheric condition detection and RF-based network communication. Alternatively, the at least one aerial device may act as a transmitter, and at least one of the selected subset of devices may act as a receiver. Another option is that the at least one aerial device may act as a transmitter, and at least one additional aerial device may act as a receiver.

[0025] According to an embodiment, the selection of the subset of devices may further be based on one or more of the following: the hardware capabilities of at least one of the plurality of devices, wireless interference near at least one of the plurality of devices, the elevation of at least one of the plurality of devices, the orientation of at least one of the plurality of devices.

[0026] In this embodiment, some additional selection criteria are defined for the selection of the subset of devices. For example, participating in RF-based atmospheric condition detection typically requires a transmitter to send additional wireless messages and a receiver to receive wireless messages and / or a processor to process wireless messages. This requires additional processing and memory resources, and thus it is beneficial to evaluate the available processing and memory resources as a selection criterion. Wireless interference near the device may also be an important factor in selecting the subset of devices. Evaluating interference and reachability-related criteria makes it possible to avoid devices that may be subject to or have been determined (e.g., based on historical data) to be subject to wireless interference that affects the device's ability to perform RF-based atmospheric condition detection. Additionally or alternatively, depending on the area to be monitored, elevation may be an important factor for the selected subset of devices. For example, a device installed at a high elevation (e.g., on a topographical high point in a city or on the top of a high-rise building) may be suitable as it may cover a larger area.

[0027] According to an embodiment, the selected subset of devices may include a first set of devices included in the area for which atmospheric conditions are to be monitored and a second set of devices having a communication link with the first set.

[0028] One of the selections for choosing a subset of devices can include a first set of devices located directly in the area and a second set of devices having a communication link with the first set. Priority values can be assigned accordingly. Since atmospheric conditions directly affect these first and second sets of devices, the detection of atmospheric conditions can be better optimized.

[0029] According to an embodiment, the atmospheric conditions can include air ionization, wherein the first function includes transmitting, receiving, and / or processing a first radio frequency signal in a first frequency band for detecting air ionization.

[0030] Air is a mixture of gases including ionized nitrogen, oxygen, water vapor, carbon dioxide, etc. We live in an ocean of air ions. In fact, an ion is nothing but an atom or molecule that has lost or gained an electron. Air ionizers are increasingly being seen for improving indoor air quality, including applications designed to reduce the spread of infections in medical environments. In this embodiment, the first radio frequency signal in the first frequency band can be used to detect air ionization. The detection can include qualitative and quantitative air ionization measurements and / or monitoring. The measurement quality may be within an accuracy threshold.

[0031] According to an embodiment, during each first time slot subset, at least one device in the selected device subset can be arranged to transmit a first radio frequency signal in the first frequency band; and at least one device in the selected device subset can be arranged to receive and / or process the first radio frequency signal in the first frequency band.

[0032] The selected device subset can include at least one transmitter and at least one receiver to optimize the communication route for RF-based atmospheric condition detection. The receiver can also have the processing ability to receive and process the first RF signal to perform RF-based atmospheric condition detection.

[0033] According to an embodiment, the processing of the first radio frequency signal in the first frequency band for detecting atmospheric conditions can be performed by an external network, where the external network is outside the wireless network.

[0034] Instead of locally performing the processing of the RF signal for detecting atmospheric pollutants by the receiver, the received RF signal can be transmitted to an external network (such as a server), and wherein the processing can be performed by a processing unit included in the external network. This is beneficial when the receiver is a resource-constrained device and is not allowed to process the received RF signal for RF-based atmospheric condition detection.

[0035] According to a second aspect, this object is achieved by a system for selecting a subset of devices from multiple devices in a wireless network to perform the following: a first function, including transmitting, receiving, and / or processing a first radio frequency signal in a first frequency band for detecting atmospheric conditions; and a second function, including transmitting, receiving, and / or processing a second radio frequency signal in a second frequency band that at least partially overlaps with the first frequency band for performing network communication; wherein the first and second functions are performed during a time period; and wherein the time period includes a first subset of time slots and a second subset of time slots; wherein the system includes: a controller arranged to perform the steps of the method according to the first aspect; the multiple devices, at least one of the multiple devices including: a communication unit arranged to transmit and / or receive the first and second radio frequency signals in the first and second radio frequency bands; a processor arranged to process the first and second radio frequency signals; and a memory arranged to store wireless network communication signals.

[0036] According to a third aspect, this object is achieved by a computer program product including instructions configured to cause the controller according to the second aspect to perform the steps of the method according to the first aspect.

[0037] It should be understood that the computer program product and the system may have embodiments and advantages similar and / or identical to those of the above method. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] With reference to the accompanying drawings, the above and additional objects, features, and advantages of the disclosed methods, systems, and devices will be better understood through the following illustrative and non - limiting detailed description of embodiments of the devices, systems, and methods. In the drawings:

[0039] Figure 1 An embodiment of a system for selecting a subset of devices from multiple devices in a wireless network to perform the first and second functions is schematically and exemplarily shown;

[0040] Figure 2 An exemplary communication between devices during a time period is schematically and exemplarily shown;

[0041] Figure 3 An embodiment of a method for selecting a subset of devices from multiple devices in a wireless network to perform the first and second functions is schematically and exemplarily shown;

[0042] Figure 4 A flowchart is schematically and exemplarily shown, which illustrates a method for selecting a subset of devices from multiple devices in a wireless network to perform the first and second functions; and

[0043] Figure 5Schematically and exemplarily shown is a device that performs first and second functions according to a method embodiment.

[0044] All the figures are schematic, not necessarily to scale, and generally show only the parts necessary for clarifying the present invention, where other parts may be omitted or only suggested. Detailed Description

[0045] Communications in many fields are moving towards the mmWave band in order to avoid the crowded 2.4 GHz and 5 GHz band spectra and enable broadband communication. For example, this can be the last-mile connection between a location with fiber access (e.g., on the roof of a building) and lighting poles that use the available data rate not only for lighting control but also for, e.g., public Wi-Fi installations, security camera image backhaul, or other data-intensive services.

[0046] MmWaves have many interesting properties that not only enable communication at this frequency but also, for example, make it possible to measure air quality. The millimeter-wave (30 - 300 GHz) band contains the fundamental rotational resonance frequencies of many molecular gases composed of carbon, nitrogen, oxygen, and sulfur. The high specificity of the rotational spectrum to organic molecules provides an mmWave spectrum that has potential use in remote sensing of atmospheric conditions. The detection of airborne chemicals is becoming increasingly important for environmental monitoring. For example, monitoring and / or measuring atmospheric pollutants caused by industrial waste, biodegradable waste, etc.

[0047] Figure 1 Schematically and exemplarily shown is an embodiment of a system 100 for selecting a subset of devices 110a - i from a wireless network to perform first and second functions. The first function (RF-based atmospheric condition detection) includes transmitting, receiving, and / or processing a first radio frequency signal in a first frequency band for detecting atmospheric conditions 130, and the second function (RF-based network communication) includes transmitting, receiving, and / or processing a second radio frequency signal in a second frequency band that at least partially overlaps with the first frequency band for performing network communication.

[0048] The first and second frequency bands may include the mmWave band. Millimeter waves (also known as the millimeter wave band) are the spectral band between 30 gigahertz (GHz) and 300 GHz. The first and second radio frequency signals may include 60 GHz signals. The (communication) devices 110a - i can be advantageously used for both RF-based atmospheric condition detection and RF-based network communication using the first and second frequency bands over a period of time; where the frequency bands may at least partially overlap. In one example, the frequency bands may completely overlap, e.g., the device uses 60 GHz to detect atmospheric conditions 130 and perform network communication. In the exemplary figures, the atmospheric conditions 130 are shown as atmospheric pollutants 130.

[0049] In Figure 1 , multiple devices 110a-i are exemplarily shown as lamp posts. The multiple devices 110a-i can be sensor devices, gateways, or any other type of device with network communication capabilities. The multiple devices 110a-i - which are lamp posts in this example - can be connected in a mesh network such that each of the multiple devices 110a-i has a communication link 115 with an adjacent device 110a-i, as shown by the dashed line 115 in Figure 1 . Other network topologies such as a star topology can also be possible. In such a (lighting) system 100, the multiple (lighting) devices are not controlled by (or not only by) traditional wired, electrical switches, or dimmer circuits, but rather are controlled by using a data communication protocol via a wired or more commonly wireless connection (such as a wired or wireless network), for example, according to a wireless networking protocol such as Zigbee, Wi-Fi, or Bluetooth. Thus, the light output of the (lighting) devices 110a-i can be controlled via a second function (RF-based network communication).

[0050] Atmospheric conditions can include the state of the atmosphere. The conditions may include atmospheric pollutants. Atmospheric pollutants 130 are substances that accumulate in the air to a level that is harmful to living organisms or materials exposed to the air. Common atmospheric pollutants 130 include smoke, fog, and gases such as carbon monoxide, nitrogen and sulfur oxides, and hydrocarbon smog. While gaseous pollutants are generally invisible, the solid or liquid pollutants in smoke and fog are easily visible. Detecting atmospheric pollutants 130 can include detecting and monitoring the atmospheric pollutants 130 in an area, such as the presence (yes / no) of atmospheric pollutants 130, detecting the amount of atmospheric pollutants 130 in the atmosphere, etc. Atmospheric conditions can include gaseous substances in the air, humidity, air moisture, etc. The gaseous substances in the air may change in concentration, for example, due to the influence during sunny days (such as ozone). Other examples of defining atmospheric conditions are not excluded.

[0051] A subset of the devices 110a-i can be selected based on the physical location of the devices 110a-i relative to the area where the atmospheric conditions 130 are to be monitored. For example, the selected subset of devices can include a first set of devices 110d contained in the area where the atmospheric conditions 130 are to be monitored, and a second set of devices 110a, 110b, 110e, 110g, and 110h that have a communication link with the first set.

[0052] The selection of a subset of the devices 110a-i can further be based on, for example, the hardware capabilities of the multiple devices, such as devices 110a-i that can be selected to have a transceiver supporting the mm-wave band and a processor for processing the mm-wave band.

[0053] Wireless interference near the devices can be an important factor in selecting the subset of devices 110d, 110a, 110b, 110e, 110g, and 110h because devices affected by high wireless interference may not be suitable for performing RF-based atmospheric condition 130 detection.

[0054] In addition, based on the area to be monitored, altitude can be considered to select the subset of devices 110d, 110a, 110b, 110e, 110g, and 110h. For example, a device installed on top of a high-rise building can be a candidate for performing RF-based atmospheric condition 130 detection and RF-based network communication at high altitude to cover a larger area.

[0055] The time periods for performing the first and second functions can include a first subset of time slots and a second subset of time slots. Each of the selected subset of devices 110d, 110a, 110b, 110e, 110g, and 110h can be assigned a first subset of time slots for performing the first function (RF-based atmospheric condition 130 detection) and a second subset of time slots for performing the second function (RF-based network communication). The assignment of time slots can be based on a priority value associated with the relative priority of performing the first function compared to the second function. For each of the selected subset of devices 110d, 110a, 110b, 110e, 110g, and 110h, the priority value can be a vector of values, each associated with performing the first function compared to the second function. The priority value can be between 0 and 1, or the sum of the priority values can be equal to 1 or can be any real number. The priority value can be a relative value (vector) defined for each first / second time slot subset and for each device in the selected subset, and it indicates the importance of the first function compared to the second function. The priority value can be determined for each of the selected subset of devices based on the relative position of the selected device to the area where the atmospheric condition 130 is to be monitored. For example, the priority value can linearly decrease / increase as a function of the proximity of the selected device to the area. The decrease / increase can be non-linear (e.g., exponential, hyperbolic, etc.). As an example, in Figure 1 , the selected device 110d can be assigned a higher priority value for performing RF-based atmospheric condition 130 detection compared to another selected subset of devices 110a, 110b, 110e, 110g, and 110h. In this case, compared to another selected subset of devices 110a, 110b, 110e, 110g, and 110h, the selected device 110d spends more time performing RF-based atmospheric condition 130 detection and less time performing RF-based network communication. Then, the selected devices 110d, 110a, 110b, 110e, 110g, and 110h are controlled to perform the first and second functions during the assigned time slots.

[0056] Alternatively or in addition to determining the priority value based on proximity, the priority value can be based on the communication traffic in the wireless network, such that the allocation of the first subset of time slots can be further based on the communication traffic in the wireless network. For example, if the communication traffic in the wireless network is high during a period of time, e.g., controlling a selected subset of devices 110d, 110a, 110b, 110e, 110g, and 110h via RF-based network communication to present a light scene, then the priority value of the RF-based network communication is higher compared to the detection of RF-based atmospheric conditions 130. The selected devices 110d, 110a, 110b, 110e, 110g, and 110h may take more time to perform RF-based network communication compared to performing the detection of RF-based atmospheric conditions 130.

[0057] The system 110 may further include an airborne device 120, where at least one airborne device 120 can be selected based on the elevation difference between the selected at least one airborne device and another selected subset of devices to detect the atmospheric conditions 130 above the other selected subset of devices. In this example, the airborne device 120 is a helicopter, and other types of airborne devices 120 (e.g., drones, UAVs, etc.) can be used. To perform the detection of RF-based atmospheric conditions 130, the airborne device 120 can be arranged to act as a transmitter to transmit a first RF signal in a first frequency band, and the other selected subset of devices 110d, 110a, 110b, 110e, 110g, and 110h can be arranged to act as receivers to receive the first RF signal in the first frequency band and process the received first RF signal for detecting the atmospheric conditions 130. Alternatively, the other selected subset of devices 110d, 110a, 110b, 110e, 110g, and 110h can be arranged to act as transmitters, and the airborne device 120 can be arranged to act as a receiver and / or processor to process the received first RF signal. In another embodiment, the airborne device 120 can be arranged to act as a transmitter, and another airborne device 120 can be arranged to act as a receiver and / or processor.

[0058] Figure 2Schematically and exemplarily shows the communication between (selected) devices 210a-b during the time period t1-t4 according to a method embodiment. Devices 210a-b are included in a selected subset of devices to perform RF-based atmospheric condition detection and RF-based network communication. In this exemplary figure, a first subset of time slots includes time slots t1 and t2 (shown by dashed lines), which are allocated for RF-based atmospheric condition 130 detection. The allocation is based on a priority value. For example, for time slots t1-t2, the priority value of the selected devices 210a-b is 0.8 for RF-based atmospheric condition 130 detection and 0.2 for RF-based network communication. If the priority values for the two functions are equal, then the allocation of time slots can be based on user input, historical data of the devices, etc. In this exemplary figure, a second subset of time slots includes time slots t3 and t4 (shown by solid lines), which are allocated for RF-based network communication. For example, for time slots t3-t4, the priority value of the selected devices 210a-b can be 0.2 for RF-based atmospheric condition detection and 0.8 for RF-based network communication. Thus, in the exemplary figure, for the first subset of time slots t1-t2, the selected devices 210a-b are arranged to perform RF-based atmospheric condition detection (shown by dashed lines), and for the second subset of time slots t3-t4, the selected devices 210a-b are arranged to perform RF-based network communication (shown by solid lines). For time slot t1 and time slot t2 or for time slot t3 and time slot t4, the priority values of the two devices 210a-b can be different.

[0059] At t1, device 210a may transmit a first RF signal in a first frequency band (e.g., mmWave band). The first frequency band may include frequency signals suitable for performing RF-based atmospheric condition detection, such as the oxygen rapid absorption 60 GHz signal. Device 210b may receive the first RF signal at t1 and may process the received RF signal to detect the atmospheric condition. At t2, device 210a may repeat the transmission, and device 210b may repeat the reception and / or processing. During a first subset of time slots t1 - t2, if device 210b does not have processing capabilities, device 210b may receive the first RF signal and may store the received first RF signal in a memory (not shown) of device 210b at t1 and / or t2. Then, the processing of the first RF signal in the first frequency band for detecting the atmospheric condition may be performed by an external network (not shown), where the external network is outside the wireless network. During the first subset of time slots t1 - t2, a second RF signal in a second frequency band (if any) may be stored in a memory (not shown) of device 210a; where the size of the memory may depend on the length of the first subset of time slots t1 - t2. As an example, if device 210a is placed in a contaminated area, device 210a spends more time in RF-based atmospheric condition detection, and thus the length of the first subset of time slots t1 - t2 may be long and requires a memory with a larger size.

[0060] At t3, device 210a may transmit a second RF signal in the second frequency band for RF-based network communication, and device 210b may receive the second RF signal. The second RF signal may include, for example, a control command for controlling device 210b. At t3, device 210b may transmit the stored first RF signal to the external network, which was stored during the first subset of time slots t1 - t2. The processing of the first RF for the RF-based atmospheric condition detection signal may then be performed in the external network, or the processing may be partially performed in device 210b and partially in the external network. In an example, when device 210b performs the processing of the first RF signal for RF-based atmospheric condition detection, device 210b may further transmit information about the detected atmospheric condition at t3. The information about the detected atmospheric condition may include an indicator of the presence / absence of atmospheric pollutants, a qualitative level assessment of gaseous substances in the air, a humidity level, an air moisture level, a quantitative measurement of atmospheric pollutants in appropriate units (e.g., atmospheric gas concentration may be expressed as a mixing ratio in ppm (parts per million) or ppb (parts per billion)).

[0061] At t3, device 210a may transmit the stored second RF signal, which was stored during the first subset of time slots t1 - t2. The communication may include control signals, sensor signals, etc. At t4, device 210a may transmit repeatedly, and device 210b may receive and / or process repeatedly. Device 210b may also transmit the second RF signal repeatedly for processing or transmitting information regarding the detected atmospheric conditions. In an embodiment, the first subset of time slots and the second subset of time slots may overlap. For example, in such an embodiment, a wide spectrum may be used in combination with a mixture of frequencies so as to perform the first function and the second function in a non-sequential manner. In another example, the first subset of time slots and the second subset of time slots may partially overlap.

[0062] Figure 3 Another embodiment of a method for selecting a subset of devices from multiple devices in a wireless network to perform first and second functions is schematically and exemplarily illustrated. In Figure 3 it, a plurality of devices 310a - g (not all devices are numbered) are shown. The plurality of devices 310a - g may be sensors, lighting devices, or any other form of device. The plurality of devices 310a - g may be included in an outdoor environment or an indoor environment. A subset of devices may be selected from the plurality of devices 310a - g to perform both RF-based atmospheric condition 330 detection and RF-based network communication in the area 340a represented by the solid rectangle. The atmospheric condition 330 may be an atmospheric pollutant layer, such as a pollutant cloud, such as a poison in the air. An example of a pollutant cloud is an atmospheric brown cloud, which is caused by a range of airborne particles and pollutants from combustion (e.g., forest fires, cars, and factories), biomass burning, and industrial processes with incomplete combustion. The selected subset of devices in area 340a may be selected to perform both RF-based atmospheric condition 330 detection and RF-based network communication over a period of time; wherein the period of time includes a first subset of time slots and a second subset of time slots. Each selected subset of devices in area 340a may be assigned a first subset of time slots to perform the first function (RF-based atmospheric condition detection) and a second subset of time slots to perform the second function (RF-based network communication) based on a priority value. The priority value may be based on the proximity of each selected device to the atmospheric condition 330.

[0063] In a subsequent time period, the spatial location of the air pollutant 330 can change relative to the region 340a. The direction of change of the spatial location of the air pollutant 330 is indicated by the arrow 345, i.e., in this example, the air pollutant 330 moves in the upper right direction. The air pollutant cloud 330 can move, expand, or contract over time. An input including tracking information can be received in a subsequent time period. The input including tracking information can be generated by a (wireless) network including a plurality of devices 310a - g or by an external network. The tracking information can include the spatial location of the (moving / expanding / contracting) air pollutant 330 relative to the region 340a.

[0064] Based on the received input, the selected subset of devices can be modified. In one example, when the air pollutant 330 moves to a new region 340b (shown by the dashed rectangle), the region 340b can then be defined for monitoring. The new region 340b can overlap with the previous region 340a. In this example, the previous region 340a is completely included in the new region 340b. The modification of the selected subset of devices can include adding additional devices to the selected subset and / or removing already selected devices from the selected subset. In Figure 3 this case, the devices included in the new region 340b and not included in the previous region 340a are added to the selected subset of devices. Since the previous region 340a is included in the new region 340b, no devices are removed from the selected subset of devices.

[0065] Alternatively or in addition to modifying the selected subset of devices, the priority values can be modified based on the received input. For each of the (modified) selected subset of devices, a modified priority value can be assigned to a first subset of time slots. When the air pollutant 330 moves from the region 340a to the new region 340b, the priority values can be modified based on the spatial location of the air pollutant 330. For example, the priority values of the devices included in the air pollutant 330 in a subsequent time period can be modified in such a way that they can spend more time performing RF - based air pollutant 330 detection. Similarly, the priority values of the devices not included in the air pollutant 330 in a subsequent time period can be modified in such a way that they can spend more time performing RF - based network communication.

[0066] Figure 4A flowchart is schematically and exemplarily shown, which illustrates a method 400 for selecting a subset of devices from multiple devices in a wireless network to perform first and second functions. In a selection step 450, a subset of devices is selected from the multiple devices to perform the first and second functions based on the physical location of the devices relative to regions 340a, 340b to monitor atmospheric conditions 130, 330. The first function includes transmitting, receiving, and / or processing a first radio frequency signal in a first frequency band for detecting atmospheric conditions; and the second function includes transmitting, receiving, and / or processing a second radio frequency signal in a second frequency band that at least partially overlaps with the first frequency band for performing network communication. The selection 450 of the subset of devices can further be based on the hardware capabilities of each of the multiple devices, the wireless interference near each of the multiple devices, and / or the altitude of each of the multiple devices.

[0067] In an allocation step 460, a first subset of time slots included in the time period for each selected device is allocated to perform the first function (RF-based atmospheric condition detection), where the first subset of time slots can be allocated based on a priority value associated with the relative priority of performing the first function compared to the second function. The priority value can be determined for each of the selected subset of devices based on the relative position of the selected device to regions 340a, 340b to monitor atmospheric conditions 130, 330.

[0068] In an allocation step 470, a second subset of time slots in the time period is also used for each selected device to perform the second function. In a control step 480, the selected devices are controlled to perform the first and second functions during the allocated time slots. The steps of the method can be executed by a controller. The controller can be implemented in a unit separate from the multiple devices 110a-g, such as a wall panel, a desktop computer terminal, or even a portable terminal (such as a laptop computer, a tablet device, or a smart phone). Alternatively, the controller can be incorporated into one or more of the multiple devices 110a-g. In addition, the controller can be implemented in regions 340a, 340b or away from regions 340a, 340b (such as on a server); and the controller can be implemented in a single unit, or in the form of distributed functionality distributed among the multiple devices 110a-g or distributed among servers including multiple server units at one or more geographical sites. Further, the controller can be implemented in the form of software stored in a memory (including one or more memory devices) and arranged to be executed on a processor (including one or more processing units), or the controller can be implemented in the form of dedicated hardware circuits, or configurable or reconfigurable circuits (such as PGA or FPGA), or any combination thereof.

[0069] Figure 5An apparatus according to a method embodiment is schematically and exemplarily shown. As an example, apparatus 510 is shown as a lighting device or luminaire having a light source 511. A luminaire 510 is a device or structure arranged to emit light suitable for illuminating an environment, thereby providing or substantially contributing to illumination on a scale competent for this purpose. The luminaire 510 includes at least one light source 511 or lamp (such as an LED-based lamp, a gas discharge lamp, or a filament bulb, etc.), optionally any associated support, housing, or other such enclosure. Each luminaire 510 can take any one of various forms, such as a ceiling-mounted luminaire, a wall-mounted luminaire, a wall washer, or a freestanding luminaire (and the luminaires do not necessarily all have the same type), an outdoor light pole, etc.

[0070] Apparatus 510 may include a communication unit 513, which may be arranged to transmit and / or receive first and second radio frequency signals in first and second radio frequency bands. Communication unit 513 allows the apparatus to communicate with other devices and / or a central controller (such as a lighting controller and / or a building management system (BMS)) via input interface unit 514. Unit 513 may include a wireless transceiver and may provide communication via radio frequency using a protocol such as Wi-Fi, Bluetooth, or Zigbee. Input interface 514 may be used to receive an input in a subsequent time period; wherein the input indicates tracking information of an atmospheric pollutant layer relative to a selected subset of devices.

[0071] Apparatus 510 may include a memory unit 512, such as one or more random access memories (RAM), read-only memories (ROM), dynamic random access memories (DRAM), fast cycle RAM (FCRAM), static RAM (SRAM), field programmable gate arrays (FPGA), erasable programmable read-only memories (EPROM), electrically erasable programmable read-only memories (EEPROM), microcontrollers, or microprocessors. Memory unit 512 may be arranged to store a first signal received for RF-based atmospheric condition detection and / or a second RF signal for RF-based network communication.

[0072] Apparatus 510 may include a processing unit 515 arranged to process the first and second radio frequency signals. Method step 400 may be executed by processing unit 515 of apparatus 510.

[0073] In one example, the atmospheric conditions can include air ionization. Air ionizers (not shown) have been seen to be increasingly used as devices to improve indoor air quality, including applications designed to reduce the spread of infections in medical environments. Air ionizers (not shown) are well-known devices that have first been applied to clean rooms in semiconductor manufacturing sites. Such devices generally blow a stream of positive and / or negative air ions into the room air, where they remove particulate matter by increasing gravitational deposition and electrostatic attraction to walls and other surfaces. Air ionization can be performed using an ionizer that generates ions in a process called corona discharge. Other processes for ionizing air are also well-known in the art. Typically used ionizer modules consist of one or more sharp ionizer pins driven at high voltage. Dust typically accumulates at these pins and causes reduced functionality, especially if the dust is wet or otherwise conductive. (If a combination of both positive and negative ions is used, dust accumulation may be alleviated.) Since the mid-20th century, air ionization has been monitored in industrial environments to assess air quality in manufacturing clean rooms.

[0074] As is known in the prior art, monitoring of air ionization in a room can be performed by an ion counter. However, monitoring using an ion counter has many drawbacks and is not easy to use. One reason is that the concentration can vary super-locally due to air flow and ion drift. In addition, the measurement devices typically generate noise because they use a fan to draw in the air to be analyzed. Thus, the methods disclosed in the prior art have the drawback of consuming ions and reducing the ion concentration during ion counting.

[0075] Detecting a first radio frequency signal (e.g., 60 GHz) in a first frequency band (millimeter wave) for detecting air ionization can include detecting the interaction between air charge and the first radio frequency signal. This allows for remote qualitative and, within limits, quantitative air ionization measurements. Detection of air ionization can include monitoring and / or measuring air ionization, which allows for the evaluation of the entire air volume penetrated by the radio frequency beam. Thus, such measurements show the co-movement effect of multiple air ionizers (not shown) installed within the same building space (not shown). In addition, the complex effects of air movement and air flow shadows can be monitored.

[0076] In one example, the detection of air ionization can be based on the damping effect on a first radio frequency signal when it penetrates the ionized air. In one example, the detection of air ionization can include anomaly detection of an ionizer system (not shown), for example, looking for deviations from normal in the air ion concentration. For example, such anomaly detection does not require, for example, measuring the ion concentration near the mouth of an occupant of the area. Similarly, the ionization system can also be used only for upper air disinfection, thus relying on air flow to bring the air to be cleaned into the upper space of the room above a height of 2.3 m. When directly measuring the ionization of the inhaled air, the first radio frequency signal should penetrate the air volume near the head of the occupant. Since the warm and humid air exhaled by the occupant tends to flow upward, it is placed directly above the head of a person sitting in a meeting room.

[0077] The first radio frequency signal is transmitted in a certain air volume, and the air volume should be tested for sufficient ionization. The transmitter or transceiver of the first radio frequency signal can be integrated in the lighting device or may be an external device outside the lighting device. The ionization system (not shown) causes charged particles (such as dust) or air humidity. When the first radio frequency interacts with the charged particles, the first radio frequency signal is scattered. The scattered first radio frequency can be received by a receiver and analyzed to perform the first function of detecting air ionization. The receiver can be integrated in the lighting device or may be an external device outside the lighting device. The processing can be done at the same receiver or at an external device (such as an external computer, cloud, etc.). A control device (not shown) can be arranged to control the transmitter / receiver / receiver for transmitting, receiving, and processing the first radio frequency signal for detecting air ionization. The control device can be integrated in the lighting device and / or outside the lighting device. The charged aerosol particles in the air produce significant backscattering. The higher the charge, the more energy of the scattered first radio frequency signal, and it can be measured at positions other than the directly forward position. In this example, at least two antennas (for example, a transmitter and a receiver antenna) can be used to measure the loss in RF transmission due to scattering.

[0078] In one example, the transmission of the first radio frequency signal is directed in such a way that the first radio frequency signal does not directly reach the occupant, so as to minimize any radiation to the occupant. For example, a lighting device can be arranged to transmit the first radio frequency signal; and the detection of air ionization is assigned to a pair of lighting devices, which can advantageously be located in room lighting devices for minimizing the RF exposure of the occupant while still being able to measure the ionization in the volume of air of interest near the occupant's head. Alternatively and / or additionally, the pair of lighting devices can be assigned such that the first radio frequency is spatially well away from other interfering and reflecting objects, such as metal surfaces (HVAC ducts) and mirrors. Thus, the light beam travels only in free air and is thus only scattered such that the wireless signal reaches the receiving lighting device. Optionally, based on WiFi CSI, a subset of the multipath signals can be selected to determine ionization; for example, the wireless multipath reflected from the metal surface of a whiteboard on the wall is discarded in the measurement of ionization, and only the more direct scattered signal path (with a shorter flight time) of 60 GHz WiFi CSI is used.

[0079] In one example, one or more transmitters (such as lighting devices) of the first radio frequency signal are placed outside the light beam axis. In another example, one or more transceivers of the first radio frequency signal operate in a time-sequential manner as transmitters (e.g., transmitting the first radio frequency signal) and receivers (e.g., receiving the scattered first radio frequency signal). In another example, a data station integrated in a laptop or other mobile device can be used as a scattered energy detector. With the mm-wave beam steering capability, the position mapping of those can be possible. The system only has to ensure that the station is not directly addressed by the beam and is able to search for scattering. In another example, the scattered diagnosis occurs beside the normal transmission towards other receivers with a focused beam.

[0080] With the proposed method, the spatial distribution of ionized particles can be back-calculated (using an algorithm similar to back-projection used in computed tomography). The more transmitters and receivers taken into account, the better the observation of local ionization. This can help to locate even a single failing ionizer or non-operating ventilation. In one example, the transceiver / transmitter / receiver of the first radio frequency signal can be integrated with the lighting installation and / or the ionizer system. In one example, combining multiple RF transmitters / monitors, room locations with less scatter can be used to locate the activity of the ionizer, the ionized air, and / or the actual distribution of non-functional air ionizers. In another example, the ionizer system gets feedback on the ionized air distribution in order to optimize the power consumption and / or wear of the ionizer. In another example, information on insufficient ionization and / or indication of a very faulty ionizer can automatically result in a service call. In another example, the air ionizer operation utilizes coded ionizer methodology. The scatter receiver uses the ionizer modulation mode to learn which radio frequency scatter originates from the scatter of ions in the air as opposed to other radio frequency scatter effects present in the room that are not related to the ionizer activity.

[0081] When the computer program product runs on the processing unit 515 of a computing device (such as the processor 515 of device 510), the method 400 can be executed by the computer program code of the computer program product.

[0082] It should be noted that the above embodiments illustrate rather than limit the invention, and those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0083] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those recited in the claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware including several distinct elements and by means of a suitably programmed computer or processing unit. In a device claim enumerating several components, several of these components can be embodied by the same item of hardware. 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.

[0084] Aspects of the present invention may be implemented in a computer program product, which may be a collection of computer program instructions stored on a computer-readable storage device and executable by a computer. The instructions of the present invention may be in any interpretable or executable code mechanism, including but not limited to scripts, interpreted programs, dynamic link libraries (DLLs), or Java classes. The instructions may be provided as a complete executable program, a partial executable program, a modification (e.g., update) to an existing program, or an extension (e.g., plug-in) to an existing program. Additionally, portions of the processing of the present invention may be distributed over multiple computers or processors or even “the cloud”.

[0085] Storage media suitable for storing computer program instructions include all forms of non-volatile memory, including but not limited to EPROM, EEPROM, and flash memory devices, magnetic disks such as internal and external hard drives, removable disks, and CD-ROM disks. The computer program product may be distributed on such storage media or may be supplied for download via HTTP, FTP, email, or by a server connected to a network such as the Internet.

Claims

1. A method for selecting a subset of devices from multiple devices in a wireless network to perform the following: - A first function, including transmitting, receiving, and / or processing a first radio frequency signal in a first frequency band for detecting atmospheric conditions; and - A second function, including transmitting, receiving, and / or processing a second radio frequency signal in a second frequency band that at least partially overlaps with the first frequency band for performing network communication; wherein the first and the second functions are performed during a time period; and wherein the time period includes a first subset of time slots and a second subset of time slots; wherein the method includes: - Selecting a subset of devices based on the physical location of the devices relative to the area where the atmospheric conditions are to be monitored; - Allocating the first subset of time slots to each selected device to perform the first function, wherein the first subset of time slots is allocated based on a priority value associated with the relative priority of performing the first function compared to the second function; - Allocating the second subset of time slots to each selected device to perform the second function; - Controlling the selected devices to perform the first function and the second function respectively during the allocated time slots.

2. The method according to claim 1, wherein the selected subset of devices is further arranged to transmit information about the detected atmospheric conditions in the second subset of time slots; wherein the information is obtained in the first subset of time slots.

3. The method according to claim 1, wherein a priority value is determined for each in the selected subset of devices based on the relative position of the selected devices within the area where the atmospheric conditions are to be monitored.

4. The method according to claim 1, wherein the priority value indicates communication traffic in the wireless network, such that the allocation of the first subset of time slots is further based on the communication traffic in the wireless network.

5. The method according to claim 1, wherein the method further includes: - Receiving an input in a subsequent time period; wherein the input indicates tracking information of an atmospheric pollutant layer relative to the area.

6. The method according to claim 5, wherein the method further includes modifying the selected subset of devices based on the received input.

7. The method according to claim 5, wherein the method further includes: - Modifying the priority value based on the received input; - Based on the modified priority value, allocating the first subset of time slots to each device in the selected subset of devices.

8. The method according to claim 1, wherein the multiple devices include at least one lighting device; and wherein the light output of the at least one lighting device is controlled via the second function.

9. The method according to claim 1, wherein the multiple devices include at least one aerial device; and wherein the at least one aerial device is selected based on the altitude difference between the selected at least one aerial device and another in the selected subset of devices to detect the atmospheric conditions above the other selected subset of devices.

10. The method according to claim 1, wherein selecting the subset of devices is further based on one or more of the following: - The hardware capabilities of at least one of the multiple devices, - Wireless interference near at least one of the multiple devices, - The altitude of at least one of the plurality of devices, - The orientation of at least one of the plurality of devices.

11. The method according to claim 1, wherein the atmospheric conditions include air ionization; wherein the first function includes transmitting, receiving, and / or processing a first radio frequency signal in a first frequency band for detecting air ionization.

12. The method according to claim 1, wherein during each time slot in a first subset of time slots, - At least one device in a selected subset of devices is arranged to transmit a first radio frequency signal in the first frequency band; and - At least one device in a selected subset of devices is arranged to receive and / or process a first radio frequency signal in the first frequency band.

13. The method according to claim 1, wherein the processing of the first radio frequency signal in the first frequency band for detecting atmospheric conditions is performed by an external network, wherein the external network is external to the wireless network.

14. A system for selecting a subset of devices from a plurality of devices in a wireless network to perform the following: - A first function, including transmitting, receiving, and / or processing a first radio frequency signal in a first frequency band for detecting atmospheric conditions; and - A second function, including transmitting, receiving, and / or processing a second radio frequency signal in a second frequency band that at least partially overlaps the first frequency band for performing network communication; wherein the first and second functions are performed during a period of time; and wherein the period of time includes a first subset of time slots and a second subset of time slots; wherein the system includes: - A controller arranged to perform the steps of the method according to any one of claims 1-13; - The plurality of devices, at least one of the plurality of devices including: o A communication unit arranged to transmit and / or receive the first and second radio frequency signals in the first and second radio frequency bands; o A processing unit arranged to process the first and second radio frequency signals; and o A memory unit arranged to store the first and second radio frequency signals.

15. A computer program product comprising instructions configured to cause the controller according to claim 14 to perform the steps of the method according to claim 1.

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