Battery-operated gateway for obtaining the geographical location of short-range beacons via a low-power wide-area network

Abstract

The battery powered gateway demodulates signals from whitelisted short-range beacons and processes and stores the data in memory. Periodically, the collected data is transmitted in an LPWAN frame along with the gateway's geographic location. The battery powered gateway can be used for multiple years without the need to replace the battery and may be used to enable the deployment of a low-cost infrastructure to connect short-range beacons to any cloud application. Typical application areas include (but are not limited to) asset inventory management, asset tracking, or sub-metering.

Description

Technical Field

[0001] The present invention relates to the Internet of Things, and more particularly, to a method for implementing a power saving mechanism using a deep sleep method while connecting short-range devices to a Low-Power Wide-Area Network.

Background Art

[0002] The Internet of Things ("IoT") is a type of communication network in which multiple sensors communicate with a backend infrastructure to optimize, for example, the operation of a city or business. IoT applications may rely on a class of wireless systems under the general name of Low-Power Wide-Area Network ("LPWAN"), which operates under the regulation of short-range devices ("SRD") and is particularly suitable for devices that need to send only a few bytes of messages per day. The LPWAN technology may be proprietary or open standards and is designed to support large-scale IoT applications with a very large number of connected devices. One of the most common use cases is the tracking of unpowered assets in logistics, retail, manufacturing, smart cities, and agriculture.

[0003] LPWAN uses a star topology architecture in which multiple access points ("APs") are placed between multiple devices and the communication network. These access points ("APs") can backhaul the data to the LPWAN core network using multiple different communication technologies (such as 3G, 4G, Ethernet, Wi-Fi, etc.). When installed at high altitudes and outdoors, LPWAN APs can cover up to dozens of kilometers with thousands of devices within the service area of a BS. In the case of deep indoor applications such as gas or water metering, repeaters can be installed to extend LPWAN coverage within a building. Since LPWAN systems generally use license-exempt spectrum, mechanisms to ensure fair use of frequency resources are realized by duty cycle (1% or 10%), "listen before talk", or "frequency hopping" mechanisms. Devices, access points, and repeaters need to respect the limitations and thus can only meet low throughput requirements. Multiple examples of LPWAN commonly used in today's world are Sigfox and LoRaWAN.

[0004] Sigfox relies on ultra-narrowband ("UNB") technology, in which high selectivity filtering and a narrower signal bandwidth (100 [Hz]) are combined to improve the sensitivity threshold. Two modulation schemes of 100 [bps] and 600 [bps] are available, and it is possible to improve the message success rate by repeating each uplink frame with a maximum payload of 12 bytes up to 3 times in a plurality of different frequency channels. For example, using a standard configuration (such as 3 frames per message, 100 [bps], and each device with a duty cycle of 1%), it is possible to transmit up to 72 bytes per hour, and using a high-capacity configuration (such as no repetition, 600 [bps]), it is possible to transmit 1296 bytes per hour, which is 18 times that of the standard configuration.

[0005] LoRaWAN uses chirp spread spectrum technique ("CSS"), and thanks to the coding gain depending on the spreading factor, this chirp spread spectrum technique reduces the sensitivity level below the noise threshold. In the case of a bandwidth of 125 [kHz], using a spreading factor of 12, a device can transmit up to 438 bytes per hour at the application layer, whereas in the case of a spreading factor of 7, it increases the amount of data that can be transmitted up to 14455 bytes per hour.

[0006] Separate from low throughput networks, SRD ECC Rec. 70-03 also encapsulates a number of different usage patterns including broadband data ("WB") transmission provided by standards such as Bluetooth®, RFID, NFC, Wi-Fi, or UWB. Both LPWAN devices and WB devices use very low power, similar to LPWAN devices, but while LPWAN is optimized for long-range low throughput communication (a few bytes over tens of kilometers), WB, on the other hand, uses license-exempt spectrum and is designed for short-range high throughput communication (a few kilo / megabytes over a few meters). WB wireless networks are composed of multiple access points that connect devices to the WB core network using supporting communication technologies (such as Ethernet, xPON, 4G, etc.). The range of WB AP coverage is 20 to 50 [m] indoors.

[0007] A short-range beacon ("SRB") is a subclass of WB SRD, and the WB SRD broadcasts an advertisement frame ("ADV") containing one or more unique identifiers ("UID") at regular intervals. The UID and the few bytes transmitted with the UID may be used to determine the physical location of the SRB, track customers, or trigger location-based actions on the device such as check-ins or push notifications on social media. However, it is important to note that the SRB is small, consists of only a few electronic chips, and is powered by a small coin battery. GNSS modules (or equivalent high-precision geopositioning modules) are not commonly seen in SRBs as they are costly and require a significant amount of energy. As a result, the SRB cannot broadcast its absolute position, and the positioning of the SRB can only be achieved by indirect methods, and new methods are the subject of this patent application. The SRB is not normally attached to, paired with, or controlled by a network infrastructure in its normal operation. The most common SRBs available on the market today rely on the Bluetooth® Low Energy ("BLE") standard.

[0008] BLE is a wireless personal area network technology that was designed and marketed by the Bluetooth Special Interest Group ("Bluetooth SIG") for new applications in the healthcare, fitness, beacon, security, and home entertainment industries. Compared to classic Bluetooth®, Bluetooth® Low Energy significantly reduces power consumption and cost while maintaining an equivalent communication range. Supported by most operating systems for smartphones and computers, BLE has gained significant momentum not only in consumer applications but also in the industry. A Bluetooth® beacon is a hardware transmitter, a type of Bluetooth® Low Energy and SRB device, that broadcasts an identifier to nearby portable electronic devices. The format of BLE beacons conforms to various standards such as iBeacon or Eddystone UID defined by industry leaders.

[0009] The communication protocol used by SRB is a low-power communication protocol. While this low-power communication protocol is designed to last for years, it also enables the production of devices with a smaller size. Also, as the market has adopted these technologies on a large scale, the prices of electronic components have significantly declined over the years. The handheld cellular devices that support these protocols have also increased dramatically over the years. For these reasons, small SRB tags have become very common in the IoT area, especially for automatic inventory applications and asset tracking applications. To function correctly, IoT applications using SRB rely on a high-density infrastructure of gateways. These gateways are usually connected to a power output one by one (within the maximum range of SRB, which is 10 meters) and use Wi-Fi, a cellular line, or a wired line to backhaul information to the Internet.

[0010] A battery-operated gateway ("BGW") is an electronic device that relays information between multiple electronic devices and a communication core network, and the power source of this electronic device consists of a (primary or rechargeable) battery. The BGW usually functions as a transparent node in end-to-end communication, receiving, processing, and transmitting data while minimizing information loss. The BGW can implement a network operation method to control the flow of information and optimize the efficiency of resource utilization. The BGW can also embed additional operation and maintenance functions such as geographical location and report its location to the network regularly.

[0011] Battery-operated gateways for short-range beacons ("SRB BGW") exist in the market, but those battery-operated gateways do not rely on LPWAN to backhaul data to the Internet and do not provide a multi-year lifespan without battery replacement. This is mainly due to the high throughput and low latency nature of the SRD protocol, which requires the gateway to always send and receive data without the option of entering a deep sleep mode that conserves battery. Also, for features such as firmware upgrade over the air ("FOTA"), most SRB BGWs can communicate bidirectionally with an SRB in pairs, so both the SRB and the SRB BGW need to communicate for a long time.

[0012] In the case of a mesh network, each relay node may be considered an SRB BGW, but it does not backhaul information via LPWAN and thus provides only short-range connections. Connectivity to the core network is ensured via a sink / source node connected to the Internet.

[0013] The object of this application is to disclose a battery-operated gateway for the geolocation of SRBs via LPWAN, the battery-operated gateway collecting a large amount of input data (or ADV) from a short-range network such as BLE, and then transmitting such a large amount of data in a single message via a long-range LPWAN such as Sigfox, thereby overcoming the drawbacks of existing solutions. A further object of this application is to disclose a deep sleep strategy for such a gateway, the deep sleep strategy being executed between the collection of short-range network inputs and the transmission of output data via LPWAN to reduce the energy consumption for enabling the gateway as a wireless device. A further object of this application is to disclose an algorithm that aggregates data from multiple SRDs collected in a short-range network format into a single LPWAN format message, making it possible to save on throughput.

[0014] This application aims to demonstrate how such a system can operate in the industrial context of real-time inventory management and asset tracking, in contrast to other solutions and devices that rely on such power and / or communication networks in the field of inventory management and asset tracking, without the need to have a single device connected to a power outlet or to rely on a public cellular communication network or a wired communication network. SUMMARY OF THE INVENTION

[0015] The BGW acquires, processes, and transmits via LPWAN the information contained in the ADV of the fleet of SRBs located in the vicinity of the gateway. The transmission of the SRB ADV is only on the uplink and is triggered by timer T ADV or an external event.

[0016] The general ADV format for the SRB is - The header [10.1] is several bytes that describe the payload size and type. The header also includes the physical layer preamble. - The unique identifier (UID) [10.2] is usually the media access control ("MAC - 6 bytes"), which is composed of the organizationally unique identifier ("OUI - 3 bytes") and the network interface specific ("NIC - 3 bytes"). - The data is generally several tens of bytes and consists of additional blocks of two types of information, the identifier Block i ID [10.3] and the data Block i Data [10.4]. The data block may include, for example, temperature or battery level, while the identifier block may be hierarchically organized. - The CRC [10.5] is the cyclic redundancy check (physical layer). may be described as such.

[0017] From a high-level perspective, the BGW executes three sets of routines at regular intervals or when triggered by a sensing event. The first routine, named "data acquisition" ("DAC"), aims to acquire and save SRB ADV data, while the second routine, named "data transmission" ("DTR"), aims to send the ADV data aggregated from the first routine to the cloud or the backend of an LPWAN technology (such as Sigfox or other platforms) via LPWAN. The first routine is usually executed multiple times before the second routine. The third routine, named "geolocation" ("GEO"), aims to acquire the geographical location of the BGW by using GPS, Wi-Fi, and / or BLE data sniffing, or receiving messages from network cloud post treatment methods (such as triangulation, machine learning, etc.). These post calculations are outside the scope of this patent, and since DAC and DTR remain the same and are value-added services provided by the LPWAN cloud owner, they will not be described below.

[0018] (Timer T DAC or triggered by an external sensing event) The data acquisition (DAC) routine - Wake up from deep sleep mode, - Duration W DAC Demodulation of SRB ADV during the sniffing window with - Measurement of the received signal strength indicator (RSSI) of each SRB ADV, - Filtering of ADV data based on user-defined criteria for headers, UIDs, data blocks, or RSSIs, - Storage of the filtered ADV data into memory registers, - Fall back into deep sleep mode, is.

[0019] For each demodulated beacon, the BGW stores in the memory register at least the UID of the SRB, the content payload, the RSSI, and the timestamp. To filter eligible SRBs connectable to the BGW, for example, whitelisting on the SRB UID range against an organizationally unique identifier (OUI) can be implemented to demodulate only SRBs from a specific manufacturer. If the identifier block is organized as a customer identifier Block customer ID and a project identifier Block project ID it may be possible to filter only a given customer or project. Filtering options and codes can be configured by the downlink via LPWAN and enable over the air update of the BGW configuration.

[0020] The demodulation or sniffing window during the duration of the DAC routine depends on the configuration of the ADV beacon of the SRB, and it is recommended that the sniffing interval be N times the average ADV interval.

[0021] Aggregation of data

[0022] Describe the implementation of the DAC routine in the context of Bluetooth (R) Low Energy (BLE) for short - range protocols and Sigfox as LPWAN. The DAC routine aggregates and compresses the ADV of SRBs. Assuming the SRB is a BLE beacon using the iBeacon (R) format, the frame size is 31 bytes with a UUID (16 bytes) and a major ID and a minor ID (each 2 bytes). The SRB BGW demodulates all of the SRB frames but discards SRB frames that do not fully or partially match the UUID configured in the SRB BGW. Further, since BLE frames with low RSSI are likely to be radiated from SRBs far away, the SRB BGW may also discard those BLE frames with low RSSI. For frames registered in the whitelist, only the major ID (2 bytes) is retained in memory and will then be transmitted during the DTR routine. Since the Sigfox uplink frame has a 12 - byte payload, the compression rate of the DAC in the presented configuration is 92.3%.

[0023] If more SRBs need to be registered in the whitelist, then the minor ID may also be used next.

[0024] (Timer T DTR or triggered by an external sensing event) The data transmission (DTR) routine - Wake up from deep - sleep mode, - Rank the memory entries according to configurable criteria (such as the maximum number of occurrences, maximum RSSI, oldest timestamp, etc.), Creation of an LPWAN frame payload by concatenating data from the memory entry with the highest priority, where a compression technique may be applied to send only a part of the UID or only specific blocks of information (sending). - Transmission of an LPWAN frame until success when information is available. - Deletion of a transmission entry sent from a memory register. That's it.

[0025] (Triggered by the end of DTR) The geolocation (GEO) routine - Assigns priorities to each geolocation acquisition method according to a configuration implemented by the user or hardware manufacturer (e.g., in the order of the acquisition method with the lowest energy consumption to the acquisition method with the highest energy consumption, such as (1) Wi-Fi, (2) BLE, (3) GPS). - Starts from the geolocation acquisition method with the highest priority and acquires geolocation information. 〇 If the acquisition of geolocation information is successful, it is sent via LPWAN The geographical location information and returns to the deep sleep mode. 〇 If the acquisition of geolocation information is not successful, use the next priority geolocation acquisition method to acquire the geolocation. - Returns to the deep sleep mode. That's it.

[0026] The DAC routine and the DTR routine are triggered by a timer or an external event (such as movement detection or presence detection). Since the frequency band used by LPWAN is generally the ISM band, the timer of the DTR routine needs to be set to comply with local regulations regarding media access control (such as duty cycle or listen before talk). In Europe, the timers for DAC and DTR may be set to 10 minutes and 60 minutes respectively, for example. The SRB ADV interval is selected to be significantly smaller to meet the industry standards for connecting to a handheld device (as the primary connection for the SRB) and to save energy for the BGW, enabling the data sniffing period of the BGW to be relatively short.

Table 1

[0027] The BGW uses the downlink frame to - the beacon white list parameters, - the data sniffing window W DAC and the duration T of the beacon demodulation period DAC 、 - the behavior T of the low-power wide-area network transmission DTR 、 - the geolocation parameters and priority preferences, may be configured to be updated.

[0028] The lifespan of the BGW increases with the duration of the deep sleep mode with the lowest power consumption. Also, the DAC parameters, DTR parameters, and GEO parameters have a significant impact, and it is recommended to adjust the parameters according to the use case. Although it is necessary to consider some of the multiple parameters, the environment (such as indoor or outdoor), the speed of movement, and the density of SRBs are the most important. When the SRB and BGW are located indoors, the success rate may be low and the energy consumption may be high, so it is recommended to avoid using the GNSS method in the GEO routine. In this case, low-energy methods such as "Wi-Fi data sniffing" or "BLE data sniffing" are recommended. The acquisition interval T of the BGW beacon DAC quantifies the ability of that BGW to detect the presence of SRBs in the vicinity (about 20 m) of the BGW. For example, in the case of an SRB moving at a low speed due to being attached to furniture in an office space and a BGW fixed to the wall, an increase in the value T DAC is unlikely to affect the detection ability of the system, but on the other hand, it saves battery. The data transmission interval T DTR affects the throughput of the BGW and the accuracy of obtaining the geographical location. When the density of SRBs in the vicinity of the BGW is high, it is recommended to decrease T DTR so that more data can be relayed by LPWAN. Since LPWAN generally uses unlicensed spectrum, the value of T DTR will be limited to 10 minutes, for example, with respect to the 868 [MHz] ISM band in Europe.

[0029] To increase the system throughput and the system's ability to relay more information from the SRB to the LPWAN while complying with regulations, it is possible to introduce various strategies. In the case of Sigfox, a higher modulation scheme may be used and frame repetition may not be necessary, while a lower spreading rate provides a greater throughput in LoRaWAN. Both of these strategies result in a reduction in the maximum transmission range by reducing the available link budget.

[0030] Throughput of the BGW

[0031] The throughput of the BGW is defined as the uplink throughput between the BGW and the LPWAN. As described in the DAC routine and the DRT routine, the advertisement frame ("ADV") of the SRB is processed and compressed by the BGW and transmitted as a block of size S SRB and each SRB is allocated the same number of bytes. Therefore, expressing the throughput of the BGW in blocks per day is convenient for reflecting the number of SRBs that can be bridged to the LPWAN. The results are shown in Tables 2 and 3.

Table 2

Table 3

[0032] Using the typical values in Table 1, the throughput of the BGW is 120 SRB blocks per day for 100 [bps] modulation.

[0033] Battery life

[0034] The battery life of the BGW depends on a number of factors and ranges from 6 months to 15 years for the values considered in Table 4. The following battery monitoring and operations are available. - The BGW battery level [20.3] is periodically sent to the LPWAN as in-band signaling to facilitate monitoring of the battery. - Configuration parameters may be updated by a downlink LPWAN message to optimize battery consumption. - The BGW is designed to be able to replace the battery.

Table 4

[0035] The DAC routine and the DTR routine may also be executed based on sensing events such as detected movement. The DTR routine needs to comply with frequency band regulation (e.g., every 20 minutes), but there is no regulation for the DAC routine, and therefore, it is impossible to predict the battery life. In order to maximize the life of the BGW, in any case, it is recommended to implement a data acquisition interval to avoid rapid drainage of the battery. Such a policy can, for example, "execute the DAC routine every 10 minutes while movement is detected and every hour otherwise". Potential sensing events may be acceleration (and / or orientation also provided by the same sensor, i.e., the accelerometer), movement detection, light detection, temperature threshold or deviation, pressure (altitude change).

[0036] Deep sleep strategy

[0037] LPWAN protocols such as Sigfox and LoRaWAN allow the SRB BGW to enter deep sleep at any time when it is not transmitting data and sensing.

[0038] Using the typical values of Table A, over a period of one hour, - Each DAC event of 5 seconds occurs 6 times, - One DTR event of 2 seconds (when assuming a 12 - byte Sigfox transmission based on European rules), and - One GEO event of 15 seconds on average (under the assumptions of Table D) will exist.

[0039] As a result, the SRB BGW will be active for only 1.31% of that time, and for the rest of the time, the overall system will be in deep - sleep mode. The deep - sleep period may be further extended using the sensing module [2.6] of the SRB BGW. To save energy, it is recommended to lower the sampling frequency of the sensing module (for example, every minute). Depending on whether the SRB BGW is fixed or movable, two effective strategies can be implemented.

[0040] Fixed SRB BGW with a presence detection sensor

[0041] The SRB BGW is attached at a fixed position (such as on the ceiling, wall, etc.) and will typically be used to acquire inventory equipped with SRBs while being within the beacon range of the assets. When the passive infrared ("PIR") sensor does not detect any presence (assuming that the ranges of the PIR and SRB are similar), the asset inventory is likely to remain stable, so the SRB BGW remains in the deep - sleep state. Each time the PIR is triggered, the SRB BGW executes at least one DAC / DTR cycle. The GEO cycle may be executed only as part of a daily or weekly routine as part of the keep - alive procedure.

[0042] Movable SRB BGW with an acceleration detection sensor

[0043] The SRB BGW is attached to, for example, a truck, and the SRB beacon would be attached to an asset transported by the truck, such as a returnable transport item (RTI-plastic box, roller cage, etc.). In this case, by using the SRB BGW, it may be possible to know which RTI is being transported by the truck. Whenever the truck is moving, the asset inventory maintains a stable state, and the SRB BGW executes the DAC routine / DTR routine / GEO routine. Whenever the truck remains stationary for a significant duration (e.g., for 5 minutes, etc.), the SRB BGW transitions to the deep sleep mode.

Brief Description of the Drawings

[0044]

Figure 1

Figure 2

Figure 3

Figure 3a

Figure 3b

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Figure 4

Figure 5

Mode for Carrying Out the Invention

[0045] BGW may be implemented with reference to Table 5.

Table 5

[0046] Industrial Application Field

[0047] An object of the present invention is to facilitate the deployment of a low-cost and battery-powered network infrastructure for arbitrarily connecting short-range beacons to cloud applications. The following use cases may be applicable.

[0048] Asset inventory management : In office space management, the SRB as a small footprint device may be attached to virtually any asset such as furniture. When a BGW is installed in the office, it will be possible to automatically manage the inventory of furniture in a given area without the need to manually count or scan each piece of furniture at regular intervals.

[0049] Asset tracking : In logistics, returnable industrial packaging plays an important role in making the economy more circular by replacing single-use packaging. The SRB may be attached to, for example, plastic pallets, and when BGWs are installed in transport trucks and docking areas, it will be possible to visually monitor the movement of those plastic pallets.

[0050] Sub-metering: In practical terms, instead of the device directly sending information to the cloud, the BWG may be used to aggregate data from multiple devices. For example, the consumption measurements and warnings of individual meters may be transmitted without equipping each meter with a long-range metering sensor. Thus, the BWG is used as a hub that includes most of the high-value components and most of the necessary energy consumption, and is still (more) accessible compared to meters (such as deep underground meters, etc.). This information transmission reduces the consumption and costs of individual meters (compared to information transmission that integrates LRWAN in addition to the current definition). That information transmission also increases the number of compatible meters available on the market and, in some cases, the coverage of that area.

Claims

1. A battery-operated gateway for obtaining the geographical location of short-range beacons via a low-power wide-area network, the gateway comprising: A short-range beacon receiving module capable of receiving and demodulating a plurality of SRB ADV from each SRB in the vicinity of the gateway on the uplink during a data interception window that occurs at periodic intervals at a user-defined frequency transmitted via a short-range wireless network [2.1] and A control module [2.2], wherein the control module [2.2] - A process of filtering SRB ADV data based on user-defined criteria such as headers, UIDs, data blocks, and RSSI; - A process of compressing the filtered SRB ADV so that it can be transferred within a single LPWAN frame; - A process of storing the filtered SRB ADV in a memory module [2.3]; - A process of ranking the filtered SRB ADV based on user-defined priority criteria such as the maximum number of occurrences, maximum RSSI, oldest timestamp, etc., and creating an LPWAN frame from the highest priority; - A process of receiving data from a geographical location acquisition module [2.7]; By executing, measuring the RSSI of each SRB ADV and transcribing those RSSIs into an LPWAN frame, a control module [2.2]; A memory module [2.3] capable of storing the demodulated SRB ADV data and the unique identifier (UID) of the SRB; A low-power wide-area network module [2.4] capable of transmitting and receiving long-range LPWAN frames (e.g., Sigfox network, LoRaWan, etc.); A geographical location acquisition module [2.7] that determines the geographical location of its short-range beacon using GNSS or collects supporting geographical location information such as a Wi-Fi address based on the user-defined priority and transmits the supporting geographical location information via the low-power wide-area network By using a deep sleep method triggered by the sensing module [2.6], it is in the form of a long-lasting battery designed to last for years without the need for replacement, and the power supply [2.5], A sensing module [2.6] capable of measuring physical quantities such as acceleration detection or presence detection, wherein the sensing module [2.6] triggers the processes of the short-range beacon receiving module [2.1] and the control module [2.2], and based on the input measured by the sensing module [2.6], the short-range beacon receiving module [2.1] changes the frequency of the process, and the short-range beacon receiving module [2.1] A sensing module [2.6] used to trigger a deep sleep state during the process, including, Gateway.

2. The gateway according to claim 1, further comprising an SRB receiving module capable of creating a white list based on the SRB UID range, registering the SRBs belonging to the SRB UID range in the white list, and filtering based on the SRBs registered in the white list to determine which SRBs can be connected to the gateway operated by the battery.

3. The gateway according to claim 1, wherein the gateway operated by the battery is configured to update the white list parameters of the SRB, the parameters of the data interception window, the duration of the demodulation period, the behavior of the low-power wide-area network transmission, and the acquisition and priority of the geographical location using the downlink frame.

4. The gateway according to claim 2, wherein the long-distance configuration of the short-range beacon receiving module [2.1] and the control module [2.2] can further change the creation of the white list of the short-range beacon via the low-power wide-area network.

5. The gateway according to claim 1, further comprising a power supply in the form of a rechargeable battery.

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