Patent Description:
Smart devices and wireless sensors are driving the Internet-of-Things (IoT) technology. Therefore, there is a need to connect battery-powered sensors, actuators and devices at low power levels to a remote monitor centre. The closest prior art is <CIT>. <CIT>) describes a gateway in wireless communication with end devices; the gateway is configured with two radios for transmitting <NUM>-W signals, whilst the gateway and end devices are configured for LPWAN, BLE, NBIoT, etc. but supercapacitors are employed to augment intermittent high power transmissions of ½ or <NUM> W. It also describes techniques for improving battery life performance, techniques for reducing the size of a concentrator of the gateway, with results in a smaller, more compact gateway device that consume less energy and reduced heat dissipation. Communication between the gateway device and the end devices are further modulated for optimized data transmission and/or battery power conservation. <CIT> (also <CIT>, and issued to Ericsson) describes a dual radio communication device with both long-range and short-range radios in the GSM band. It teaches that the long-range radio transmits with a relatively high power level which results in a drop in current or voltage from the power supply, thereby adversely affecting the short-range radio transmission. ) describes a system and method for a dual-mode BLE device, with BLE functionality being add-on feature within traditional BT. The dual-mode BLE device is configured to scan window based on identified idle intervals within the Bluetooth BR/EDR traffic communications. The determined scan window is then adjusted based on timing of expected advertising transmissions and/or advertising interval(s) to achieve low power consumption. In addition, the scanner may be enabled to narrow or to reduce the scan window size to lower power consumption, or the scan window can be turned on or off. <CIT>) describes a system and method for centralised monitoring and controlling power consumption of end user devices in a network; the method involves receiving raw data from plurality of end points using a data collecting devices; measuring a plurality of operating and environmental parameters of the end user devices with a plurality of sensors; collecting and storing the received raw data and the measured plurality of operating and environmental parameters in a data aggregator device; processing the received raw data from the plurality of endpoints, and the measured operating and environmental parameters with a microcontroller unit; interpreting the processed data into one or more events with the microcontroller unit; measuring a power consumption of the plurality of end points using the microcontroller unit; optimizing and controlling the power consumption of the plurality of end points based on a preset setting, and the measured and processed operating and environmental parameters using the microcontroller unit; and communicating the processed raw data, and the measured operating and environmental parameters for storage in a database using one or more communication protocols for future retrieval and usage. <CIT>) describes a wireless monitoring system for monitoring at least one person in a building. The wireless monitoring system includes a data collection device and a plurality of wireless signalling devices working in a star network topology. The signalling devices and the data collection device are adapted to send and receive FSK modulated signals in a predetermined single channel, whilst the signalling devices are adapted to send data packets, such as a heartbeat message, to the data collection device.

The following presents a simplified summary to provide a basic understanding of the present invention. This summary is not an extensive overview of the invention, and is not intended to identify key features of the invention. Rather, it is to present some of the inventive concepts of this invention in a generalised form as a prelude to the detailed description that is to follow.

The present invention seeks to provide a gateway device to aggregate data via Short Range (SR) wireless communication from a plurality of wireless sensors/actuators and to transmit the aggregated sensor data to a remote monitor centre through a Low Power Wireless Wide Area Network (LPWAN). By aggregating sensor data at the gateway device, transmission efficiency is improved; this also reduces sensor deployment costs and IoT network operating costs. When Bluetooth Low Energy (BLE) is employed for SR communication, BLE sensor discovery and connection processes are configured to conserve battery power. Artificial intelligence or machine learning to recognize a time pattern of SR communication between the gateway device and the wireless sensors/actuators allows a scanner in the gateway device to be powered on only during those necessary time periods to further conserve battery power. An advantage is that the LR communication is powered on only when the SR communication is powered down to avert SR and LR interference.

In one embodiment, the present invention provides a gateway device for an IoT system that is configured for BLE communication according to claim <NUM>.

Preferably, the SR wireless communication module comprises a chip set providing Bluetooth, Bluetooth low energy (BLE), Zigbee, near-field communication (NFC) or similar short range wireless communication. Preferably, the LR wireless communication module comprises a chip set providing narrow-band IoT (NB-IoT), Sigfox, LoRa or similar low power, long range wireless communication.

Preferably, the Bluetooth Low Energy (BLE) scanner in the gateway device being configured to listen for an IoT sensor/actuator/ device with reduced power consumption.

In one embodiment, the BLE scanner is turned on for substantially <NUM>% of the time during each scan cycle. Also, the BLE scanner is turned off during the time blocks outside the BLE connection in all the channels to conserve battery power.

Preferably, when a BLE sensor broadcast timing has drifted and BLE connection is lost, a microcontroller for controlling the gateway system creates two scan windows in a successive scan cycle, with a first scan window located one scan interval prior to the previously known connected scan window and a second scan window located one scan interval after the previously known connected scan window, and directionally shifting the first scan windows and the second scan window outwardly to the left and right by one scan interval, respectively, in each successive scan cycle to facilitate fast sensor re-discovery and re-connection, with concomitantly low power consumption.

Preferably, the BLE scanner comprises an artificial intelligence or a machine learning module disposed in the gateway device to record and learn the pattern of the BLE scanner time blocks which synchronise with the BLE sensors/actuators, so that the BLE scanner is powered on only during these time blocks to reduce power consumption. In addition, long range (LR) wireless communication with a monitor centre is initiated only when the BLE scanner connected to the BLE sensor or sensors is silent or turned off, so as to avert BLE and LR wireless interference.

This invention will be described by way of non-limiting embodiments of the present invention, with reference to the accompanying drawings, in which:.

One or more specific and alternative embodiments of the present invention will now be described with reference to the attached drawings. It shall be apparent to one skilled in the art, however, that this invention may be practised without such specific details. Some of the details may not be described at length so as not to obscure the invention. For ease of reference, common reference numerals or series of numerals will be used throughout the figures when referring to the same or similar features common to the figures.

<FIG> shows a schematic architecture of a wireless, low power sensor gateway device <NUM> according to an embodiment of the present invention. The gateway device <NUM> has low power consumption, is powered by a battery <NUM> and it includes a micro-controller <NUM> connected to a memory unit <NUM>, a short range (SR) wireless communication module <NUM> (which may include a chipset or chipsets employing Bluetooth, Bluetooth Low Energy (BLE), ZigBee, Near-field communication (NFC), or similar SR wireless technology), a low power long range (LR) wireless communication module <NUM> (which may include a chipset or chipsets employing narrow-band NB-IoT, SigFox, LoRa communication, or similar low power LR wireless technology), a setup/mode switch <NUM> and an external connection port <NUM>, besides other accessories. The SR communication module <NUM> interfaces with a plurality of sensors/actuators/devices <NUM>,<NUM>,<NUM>, etc. and collects data from the sensors/actuators/ devices and pushes sensor data into the micro-controller <NUM> for filtering and raw data aggregation into compact data packages <NUM> (as shown in <FIG>). These compact data packages <NUM> are then transmitted periodically to a remote monitor centre <NUM> through the LR communication module <NUM> (as seen in <FIG>). A software or firmware <NUM> is stored in the memory unit <NUM> for operating the micro-controller <NUM>. The gateway device <NUM> is located near a group of sensors/actuators/devices within range of the SR communication via an associated SR antenna <NUM>; by providing the gateway device <NUM> to serve a group of sensors/actuators/devices <NUM>, <NUM>, <NUM>, etc., the cost of deploying the sensors/actuators becomes lower. The cost for transmitting the data packages <NUM> to the remote monitor centre <NUM> also becomes lower. In short, there is higher efficiency and cost effectiveness in using the gateway device <NUM> in an IoT system <NUM> illustrated in <FIG>.

<FIG> shows another gateway device 110a in which a web server module <NUM> is connected directly with the micro-controller <NUM>. As seen in <FIG> and <FIG>, the gateway device <NUM>, 100a is connected to an external setup device/computer through the connection port <NUM> (such as, USB, wifi, LAN, Bluetooth, and so on). A setup routine <NUM> in the setup device/computer allows the number of sensors/actuators to be scalable (such as, adding of new sensors/actuators and associated drivers) and maintained (such as, replacing any of the sensors/actuators). During the setup mode, electric power may be supplied from the setup device/computer through the port connection <NUM>; in addition, the battery <NUM> can also be charged during setup or via this port <NUM>. The setup mode can also be done remotely through the web server module <NUM>.

In <FIG>, the IoT system <NUM> architecture is broadly described to make up of <NUM> layers, namely, a perception layer <NUM>, a network layer <NUM> and an application layer <NUM>. At the perception layer <NUM>, sensors/actuators <NUM>, <NUM>, <NUM>, etc. are continuously listening, sensing or collecting information/data about the environment or apparatus that is being monitored. The collected sensor/actuator information/data is then transmitted through the SR wireless communication to the gateway device <NUM>,100a, which is located in the network layer <NUM>. The gateway device <NUM>,100a consolidates the collected sensor/actuator information/data into data packages <NUM> and transmits the data packages <NUM> at predetermined periodic intervals through the LR wireless communication to the remote monitor centre <NUM>, which is located at the application layer <NUM>. At the application layer <NUM>, the raw sensor/actuator/device data are stored, processed and analysed, and useful information is extracted, displayed or made available to a user. When necessary to correct or adjust the apparatus being monitored, a downlink command can be issued to the associated sensor/actuator/device <NUM>, <NUM>, <NUM>, etc. or an alert is issued for maintenance action.

<FIG> shows an example of the data package <NUM> containing aggregated sensor/actuator data. Each data package <NUM> contains a header <NUM>, identity ID <NUM> of sensor/actuator/device #<NUM>, identity <NUM> of sensor/actuator/device #<NUM>, and so on. The header <NUM> may contain information on the number of sensors from which data are collected from each sensor identity ID <NUM> and the associated sensor value/digital data <NUM>. Depending on the LR wireless communication protocol, there is a limit on the size of the data package <NUM> for transmission. For example, the header <NUM> data may be restricted to <NUM> bytes, with the sensor ID and data generally making up <NUM> byte and <NUM> bytes, respectively.

<FIG> shows the setup routine <NUM> when connecting sensors/actuators/devices <NUM>, <NUM>, <NUM>, etc. to the gateway device <NUM>,100a during an initial setup process. To start the setup routine <NUM>, in step <NUM>, a computer is connected to the gateway device <NUM>,100a, for eg. via USB, wifi or LAN to the connection port <NUM>. Alternatively, the mode switch <NUM> is turned to Setup mode to scan for available SR wireless sensors/actuators, in step <NUM>. Once a wireless sensor is detected, in step <NUM>, each sensor <NUM> is registered, an ID <NUM> is assigned, and an associated name is recorded. The sensor data format is also recorded. This sensor initiation and identification are carried out for all the sensors/actuators/devices <NUM>, <NUM>, <NUM>, etc. that are within SR communication with the gateway device <NUM>,100a; the total number of sensors configured is then determined in decision step <NUM>; if no new sensors/actuators/devices are identified, the setup routine <NUM> proceeds to, step <NUM>, to discover and then define the specific data package transmission time blocks that each specific sensor/actuator/device advertises within (as illustrated in <FIG>). Then, the gateway device <NUM>,100a will be configured to scan during these specific time blocks, before ending the setup routine in step <NUM>. During configuration of the setup routine <NUM>, the gateway device (operating in a scanner mode) is configured so the IoT system <NUM> can learn and record predefined durations for scanning. Usually, the gateway device would scan continuously for a long duration over each scan cycle to capture a nearby sensor/actuator operating pattern/regime; this will consume a lot of battery power. In the present invention, during the configuration mode, the gateway device <NUM>,100a is turned on progressively at each scan cycle, from time block T1 to time block T64, to discover which time block a sensor advertises on.

In the above sensor/actuator discovery step <NUM>, operation is only for sensors/actuators that are in working order and are advertising. For sensor/actuator that has time-critical alert or contain ad-hoc message, these sensors/actuators are programmed to broadcast continuously for a minimum of <NUM> scan cycle.

In the above description, short range (SR) wireless communication employing Bluetooth Low Energy (BLE) technology has been mentioned. To improve on BLE performance, it is possible to further minimize energy consumption to achieve energy efficiency and yet maintain responsiveness of this gateway device <NUM>,100a for an IoT application. A BLE sensor/actuator/device <NUM>, <NUM>, <NUM>, etc., called an advertiser, periodically broadcasts short data packages (PDU) within an advertising window TAW, as shown in <FIG>. At the end of an advertising window, the BLE radio in the BLE sensor/actuator is powered-off until the start of the next advertising event to further conserve battery power. In order to listen to every message broadcasted by the BLE sensors/actuators, the gateway device <NUM>,100a operating in a scanner mode is turned on so that scanning windows TSW coincide with the advertising windows that are specific to an individual sensor/actuator <NUM>,<NUM>,<NUM>, etc.. Each listening or scanning cycle is defined by a scan interval TSI, and the gateway device is turned on during each scanning window.

Usually, at the start or initialization of the gateway device <NUM>,100a (BLE scanner) and the BLE sensor/actuator <NUM>,<NUM>, etc. are turned on at different times and, therefore, there is no synchronization of start time for the advertising interval (TAI) and the scan interval (TSI). As a result, the advertising event does not occur at substantially or effectively the same time as the scanning window, as seen in <FIG> except for the third advertising window in channel <NUM>. In standard BLE, the scanner is usually powered up all the time or half the time if the scan window (TSW) is half the scan interval (TSI); this consumes a lot of electrical power, thus making the use of standard BLE unsuitable for battery-operated IoT device. To reduce BLE power consumption, the present invention modifies the BLE standard to suit low power consumption for IoT use. In one embodiment of the present invention, the BLE standard is modified so that each BLE scan cycle is set at <NUM>,<NUM>, and each scan cycle is divided into <NUM> time-blocks (see <FIG>), giving a scan window TSW of <NUM>. With this modified BLE standard, the BLE radio is turned on substantially <NUM>% of the time during each scan cycle.

Table <NUM> shows a summary of the BLE parameters modified for reduced power consumption:.

A second modification is in optimizing the BLE scanner process, in the event of the BLE sensor/actuator <NUM>,<NUM>, etc. broadcast timing has drifted with respect to the gateway device <NUM>,100a (operating in scanner mode), for e.g., after replacing a battery in a BLE sensor, a BLE sensor is faulty, and so on. The present invention provides a fast connection method at low power consumption (instead of re-establishing connection via a fresh discovery operation (in step <NUM> of the sensor setup routine <NUM>)). In this fast connection method, two scan windows are created (in a successive scan cycle) from one previously known connected scan time block, so that a first scan window appears before and a second scan window appears after the previously known connected scan time block, as shown in <FIG>. For illustration, in <FIG>, the previous known connected scan time block is shown at T10, the first and the second scan windows at time blocks T9 and T11 are created in a successive scanning cycle. During each successive scan cycle, the first scan window is again shifted by one scan interval to the left hand side (as indicated by arrow A in <FIG>), while the second scan window is again shifted by one scan interval to the right hand side (as indicated by arrow B). This method is repeated for a few scanning cycles until the gateway device <NUM>,100a (operating in scanner mode) discovers the missing BLE sensor/actuator. With this method, the number of scanning cycles to re-establish sensor discovery is fewer, thus leads concomitantly to conserving some battery power. If BLE rediscovery operation fails to establish after a predetermined number of scanning cycles, a fresh sensor discovery operation is initiated (ie. initiate step <NUM>). Alternatively, if BLE rediscovery fails to establish after a predetermined number of scanning cycles, the BLE sensor/actuator is deemed missing or faulty or has failed, an alert message is sent to the remote monitor centre <NUM> for follow-up action.

In the BLE gateway device <NUM>,100a, power in short range (SR) wireless communication is relatively low, for eg. <NUM> mW, whilst the power in long range (LR) wireless communication is substantially higher, for eg. Due to proximity of the SR and LR antennae, harmful interference becomes an issue; any harmful interference will result in decrease of the effective ranges of SR and LR communication. From the aggregated advertising and scanning time blocks records, the microcontroller <NUM> is able to determine the time blocks when the SR communication are idle or silent, and the microcontroller is configured to activate LR communication only during the time blocks when the SR communication is silent. With this feature, interference or blocking of SR communication by the LR communication is averted.

The sensors/actuators/devices <NUM>,<NUM>,<NUM>, etc. may be binary devices or analog devices. Data of binary devices is defined in two states, <NUM> or <NUM>, or on or off. Data of analog devices (such as, temperature or humidity readings) can be represented in hexadecimal values. To reduce the data packet <NUM> size for the LR wireless communication to send to the monitor centre <NUM>, the latest set of sensor/actuator data is recorded in the memory <NUM> of the gateway device <NUM>,100a; if there are no changes to the binary data or pattern of the analog data is repeated, the gateway device <NUM>,100a will only send a heartbeat message to the monitor centre stating that there is no change in data value, instead of sending all the sensor data periodically. An advantage of sending this heartbeat message is also to meet a reduced payload on certain LPWAN, such as, a package size limit of <NUM> bytes using Sigfox.

Whilst BLE wireless technology has been used to exemplify the above invention, some of the processes and methods are also applicable for use with other SR wireless technology, including other Bluetooth standards, Zigbee, NFC, and so on, and other LR wireless technology, including NB-IoT, Sigfox, LoRa, and so on. For instance, the microcontroller <NUM> employs artificial intelligence or machine learning in scheduling of SR and LR communication to avert interference is applicable for all the various types of SR and LR wireless technologies. In another instance, when there are no changes to the binary data or pattern of the analog data is repeated, the gateway device <NUM>,100a will only send a heartbeat message to the monitor centre <NUM> stating that there is no change in data value, instead of sending all the sensor data periodically. In yet another instance, when a sensor/actuator needs to send time-critical alert or ad-hoc message to the monitor centre <NUM>, the sensor/actuator has to broadcast the time-critical alert/ad-hoc message for the gateway device <NUM>,100a to pick up; in response to receipt of the time-critical alert/ad-hoc message, a downlink command can be issued from the monitor centre <NUM> to correct or adjust the apparatus linked to the sensor/actuator <NUM>,<NUM>, etc. (for eg. to trigger a fixed camera sensor to be turned on).

Claim 1:
A gateway device (<NUM>, 100a) for an IoT system configured for Bluetooth low energy (BLE) communication, comprising:
a short range (SR) wireless communication module (<NUM>) for interfacing with one or more BLE sensors, actuators or devices (<NUM>-<NUM>);
a memory unit (<NUM>) containing a software to control a micro-controller (<NUM>), wherein data from the one or more BLE sensors, actuators or devices (<NUM>-<NUM>) are aggregated into a data package (<NUM>) such that a BLE scan cycle is divided into <NUM> equal time blocks so that a BLE scan window has a scan interval lasting <NUM>; and the BLE scan window is shifted by one time block for each scan cycle to listen for any BLE sensor (<NUM>-<NUM>) that is located within range and is cyclically advertising;
a low power, long range (LR) wireless communication module (<NUM>) for transmitting the data package (<NUM>) to a monitor centre (<NUM>) at predetermined time periods;
an artificial intelligence or a machine learning module disposed in the micro-controller (<NUM>) to record time blocks when the SR wireless communication is silent and, in response, to turn on a radio associated with the LR wireless communication, so as to avert interference between the SR and LR wireless communication; and
a battery (<NUM>) for powering the gateway device (<NUM>, 100a);
characterised by:
the BLE scan window shifting and listening processes are repeated until a scan window time block substantially or effectively coincides with a time block that a BLE sensor (<NUM>-<NUM>) is advertising, and in response, the artificial intelligence or the machine learning module turns on a BLE scanner located in the gateway device (<NUM>, 100a) during these coincidental or connected time blocks to conserve power in the battery (<NUM>).