System and method for early detection of a wildfire

Abstract

The invention relates to a wildfire early detection system having a network server, a first gateway, a second gateway and multiple terminals, wherein the first gateway has a first communication interface to a communication satellite and a further communication interface to other gateways and / or terminals and / or the network server of the mesh gateway network, and the second gateway has different communication interfaces than the first gateway. The invention also relates to a method for early detection of a wildfire with the method steps of detection of a wildfire by a terminal, generation of a signal in a terminal, transmission of the signal from the terminal to a second gateway, receipt of the signal at the second gateway, forwarding of the signal from the second gateway to a first gateway, receipt of the signal at the first gateway and forwarding of the signal from the first gateway to a network server, wherein the forwarding of the signal is from the first gateway to a network server via satellite communication.

Description

[0001] SYSTEM AND METHOD FOR EARLY DETECTION OF A WILDFIRE

[0002] The invention relates to a wildfire early detection system having a network server, a first gateway, a second gateway and multiple terminals, wherein the first gateway has a first communication interface to a communication satellite and a further communication interface to other gateways and / or terminals and / or the network server of the mesh gateway network, and the second gateway has different communication interfaces from the first gateway. The invention also relates to a method for early detection of a wildfire, having the method steps of detection of a wildfire by a terminal, generation of a signal in a terminal, transmission of the signal from the terminal to a second gateway, receipt of the signal at the second gateway, forwarding of the signal from the second gateway to a first gateway, receipt of the signal at the first gateway and forwarding of the signal from the first gateway to a network server, wherein the forwarding of the signal is from the first gateway to a network server via satellite communication.

[0003] Prior Art

[0004] Systems for early detection of wildfires are known. For this purpose, the area to be monitored is monitored by means of optical sensors which can detect columns of smoke produced during a wildfire. These sensors are, for example, rotatable cameras, but they have the disadvantage that they are less effective at night and are susceptible to false detections, for example, in the case of dust clouds resulting from agricultural activities. In addition, optical systems can usually only detect the wildfire when the wildfire is already advanced and the smoke columns become visible over greater distances. Monitoring by means of an IR camera installed in a satellite from a high orbit has the disadvantage that the resolution of the cameras over the long distances prevents detection of wildfires in the early stages. A satellite is also expensive to purchase and maintain, in particular when launching the satellite. Monitoring by mini-satellites in a low orbit has the disadvantage that the satellites are not geostationary, so they require a certain amount of time to complete one orbit, during which the area is not monitored. Close-meshed monitoring requires a large number of satellites, the launch of which is also costly. Satellite monitoring also involves high carbon dioxide emissions during launch.

[0005] It makes more sense to monitor the area by means of a plurality of inexpensive, mass- producible sensors that work by means of optical smoke detection and / or gas detection. The sensors are distributed throughout the area and deliver data to a base station via radio connection.

[0006] Such a system for early detection of wildfires is presented in the document US 2008 / 0309502 A1 . In the event of a fire alarm, a sensor delivers information to a nearby control terminal, which then triggers an alarm by means of a long-range radio frequency signal.

[0007] This system has the disadvantage that the control terminal triggers the alarm and has to have a powerful RF unit for this purpose. The sensors require a GPS unit that constantly sends a signal to the control terminal; the power consumption of the sensors is therefore high, and the service life of the energy sources (batteries) of the sensors is limited.

[0008] Therefore, the object of the present invention is to provide a wildfire early detection system and a method for early detection of a wildfire which work reliably, are expandable as desired and are inexpensive to install and maintain.

[0009] The object is achieved by means of the wildfire early detection system of claim 1. Advantageous embodiments of the invention are set forth in the dependent claims.

[0010] The wildfire early detection system according to the invention has a network server, a first gateway, a second gateway and multiple terminals. A terminal has a sensor unit for detection of a wildfire. The gateways have the task of receiving data from the terminals and forwarding it to the network server. They serve as a bridge between the terminals and the network server and enable connection of term inals in the field to the back-end system . The network server is the core of the wildfire early detection system. The network server receives and processes the data packets received from the gateways. The network server enables the management of LoRa networks, the configuration of network parameters such as bandwidth, channels and transmit power. The network server communicates via different protocols (e.g., REST, MQTT, etc.) with an application which is operated as an app in the cloud, for example.

[0011] According to the invention, the first gateway has a first communication interface to a communication satellite and a further communication interface to other gateways and / or terminals and / or the network server of the mesh gateway network. By means of the communication interface to a communication satellite, a connection may be established to a communication satellite, via which data packets from other gateways, which in turn obtain data packets from the terminals, may be sent to the network server. By means of a connection via a communication satellite, a connection between the first gateway and the network server is also possible over long spatial distances.

[0012] The second gateway has different communication interfaces than the first gateway. By means of the communication interfaces of the second gateway, connection to a communication satellite is not possible. In a further embodiment of the invention, the second gateway communicates exclusively with other gateways and / or terminals and / or the network server. In particular, the second gateways do not have a single-hop connection to a network server. Communication between terminals and a second gateway is a direct one, i.e., without further intermediate stations (single-hop connection). Communication between the gateways may be through a direct single-hop connection; a multi-hop connection is also possible. This simultaneously extends the range of the mesh gateway network because the first gateway is connected to the second gateway via a multi-hop mesh network and may thus forward the data from the terminals to the network server. The connection between the second gateway network server is wireless or wired.

[0013] In a further development of the invention, the second gateway is unsuitable for satellite communication. The second gateway does not have a communication interface to a communication satellite, only communication interfaces to other gateways and / or terminals and / or the network server via wireless or wired connection. In a further embodiment of the invention, the mesh gateway network comprises an LPWAN, the LPWAN comprising a LoRaWAN. LPWAN describes a class of network protocols for connecting low-power devices such as battery-operated sensors to a network server. The protocol is designed such that a long range and low energy consumption of the terminals can be achieved with low operating costs. LoRaWAN manages with a particularly low power consumption. The LoRaWAN networks implement a star-like architecture by means of gateway message packets between the terminals and the central network server. The gateways are coupled to the network server, while the terminals communicate with a second and / or first gateway by radio via LoRa.

[0014] In a further embodiment of the invention, the mesh gateway network has a third gateway, which has different communication interfaces than the first gateway and the second gateway. Like a second gateway, the third gateway does not have a communication interface to a communication satellite, only communication interfaces to other gateways and / or terminals and / or the network server via wireless or wired connection. Therefore, the third gateway is also unsuitable for satellite communication.

[0015] In a further aspect of the invention, the second gateway communicates directly only with other gateways and terminals of the mesh gateway network, and the third gateway communicates with the network server. In a further embodiment of the invention, the third gateway communicates with the network server via an Internet connection. In a development of the invention, the third gateway communicates only with other gateways of the mesh gateway network and / or terminals. In particular, communication between terminals and a second gateway is a direct one, i.e. , without further intermediate stations (single-hop connection). Communication between the gateways may be through a direct single-hop connection; a multi-hop connection is also possible and preferable.

[0016] In a further embodiment of the invention, the second and / or the third gateway has a communication interface which provides an Internet connection to the network server. The Internet connection is a wireless point-to-point connection, preferably by means of a standard Internet Protocol.

[0017] In an advantageous embodiment of the invention, the terminals and / or the second gateways and / or the third gateways and / or the first gateways have a self-sufficient energy supply. To be able to install and operate the terminals and the first gateways connected thereto even in harsh and especially rural areas far from energy supply, the terminals and the first gateways are equipped with a self-sufficient energy supply. The energy supply may be provided, for example, by energy storage devices - also rechargeable ones.

[0018] In a further embodiment of the invention, the self-sufficient energy supply comprises an energy storage device and / or an energy conversion device. In particular, energy supply by means of solar cells should be mentioned, in which energy conversion from light to electrical energy takes place. The electrical energy is usually stored in an energy storage device to ensure energy supply even in times of low solar irradiation (for example at night). In a further configuration of the invention, the terminals and the second gateways and / or the third gateways are operated off-grid. The self-sufficient energy supply enables operation without an energy supply by external means.

[0019] In a further embodiment of the invention, the second gateways have an ACK signal generation unit. For the purposes of this invention, an ACK generation unit is a sub-server unit integrated into a second gateway, which assumes functionalities and tasks intended for the network server according to the LoRaWAN protocol. For the purposes of this invention, ACK signals are messages, commands, and functions stored on the second gateway or generated by a gateway. The ACK signal (as in “acknowledgment”) generated by the ACK generation unit is a signal used in a data transmission to acknowledge receipt. This ensures that a message is sent correctly. Similarly, the terminal does not have to be active all the time. Power consumption is reduced and the lifetime of the terminal is thus increased.

[0020] In a development of the invention, the ACK signal generation unit has a processor and a memory. The processor and memory are standard components and therefore inexpensive to manufacture.

[0021] They may include the following MAC commands of the LoRaWAN protocol (LoRaWAN

[0022] 1.1 specification of October 11 , 2017, Final Release):

[0023] • Confirmed Uplink (UL) - best effort

[0024] • Confirmed UL - end-to-end confirmation for mission-critical messages

[0025] • Downlink (DL)

[0026] • Confirmed DL

[0027] • Resetlnd, ResetConf (sec. 5.1)

[0028] • LinkCheckReq, LinkCheckAns (sec. 5.2)

[0029] • Rekeylnd, RekeyConf (sec. 5.10)

[0030] • DeviceTimeReq, DeviceTimeAns (sec. 5.12)

[0031] • Join-request, Join-accept (sec. 6.2.2, 6.2.3)

[0032] In a further embodiment of the invention, the second gateways of the mesh gateway network are front-end gateways and / or the third gateway is a border gateway. The division of the gateways into front-end gateways and border gateways significantly expands the range of the LoRaWAN network, wherein standard LoRaWAN-compatible terminals may still be employed, which can be distributed and networked far into impassable areas that are unreachable using conventional radio networks.

[0033] In further aspect of the invention, the first gateway, the second gateway and / or the third gateway have the ACK signal generation unit. All of them in the mesh gateway network have an ACK signal generation unit to acknowledge the receipt of the message sent by the terminal to the terminal connected to the respective gateway.

[0034] In a further configuration of the invention, the second gateway has a first front-end gateway communication interface for communication with a terminal and a second frontend gateway communication interface for communication with another first, second and / or a third gateway. Therefore, as a node, the second gateway is operable to communicate both with a terminal via a single-hop connection (chirp spread spectrum modulation or frequency modulation) and with a gateway via a single-hop or preferably multi-hop connection as a mesh multi-hop radio network. Both connections utilize different protocols and therefore require different interfaces.

[0035] In a further embodiment of the invention, each second gateway is suitable for point- to-point wireless communication with a plurality of terminals using single-hop (FSK) LoRa or FSK radio using the LoRaWAN protocol. Therefore, complete compatibility with commercially available LoRa terminals is provided. The second gateway communicates with the terminal via standard LoRaWAN radio protocol or via standard LoRa radio connection. Therefore, it does not need to be modified to take advantage of the mesh network. The mesh architecture is, so to speak, “transparent” for the terminal.

[0036] In a further embodiment of the invention, the second gateway and the third gateway are combined with a plurality of mesh gateway devices, and at least one of the mesh gateway devices does not have a direct IP connection. Mesh gateways are a combination of the second gateways and the third gateways. The mesh gateways talk to each another by means of the multi-hop radio network, and at least one mesh gateway is connected to the network server via the standard Internet Protocol.

[0037] In a development of the invention, the third gateway is provided for communication with the network server by means of a standard IP connection and using the LoRaWAN protocol. At least one of the second gateways communicates directly with a third gateway. The third gateway sends the data from a terminal directly to the network server by means of an Internet Protocol. This type of communication and the division of the gateways into two types of gateways significantly expands the LoRaWAN network, wherein LoRaWAN- compatible terminals may still be employed, which can be distributed and networked far into impassable areas that are unreachable using conventional wireless networks. These terminals are any commercially available devices which do not have to be adapted to use the advantages of the mesh network.

[0038] In a further configuration of the invention, the third gateway has a first border gateway communication interface for communication with a network server and a second border gateway communication interface for communication with a second gateway. That is, the third gateway is operable to communicate with a further gateway via a single-hop or, preferably, multi-hop connection as a mesh multi-hop radio network. The network server can be communicated with in a wireless or wired manner via a standard Internet connection. Both connections utilize different protocols and therefore require different interfaces.

[0039] In an advantageous development of the invention, a second gateway is integrated with a third gateway in a mesh gateway. Advantageously, the second gateway and the third gateway are grouped together in one device, namely in a so-called “mesh gateway”. Again, the integrated mesh gateways communicate with each other by means of a multihub radio network, while at least one integrated mesh gateway is connected to the network server via the standard Internet Protocol.

[0040] In a further advantageous embodiment of the invention, the mesh gateway network is a wireless multi-hop radio network. The second gateway is connected to the third gateways via the mesh multi-hop radio network, and the data from the terminals is forwarded to the network server. This removes the range limitation of the direct connection between terminals and gateways provided for by the LoRaWAN standard.

[0041] In a further configuration of the invention, the first gateway has an energy storage device which may store an amount of energy larger than the energy needed to communicate via the satellite communication interface. Therefore, the first gateway has sufficient energy reserves to perform even further tasks, such as transmitting a message from the network server to a gateway and / or terminal.

[0042] In a development of the invention, the energy storage device may store an amount of energy which is more than twice as large as the energy needed to communicate via the satellite communication interface. Therefore, the first gateway has sufficient energy reserves to perform even further tasks, in particular further communication with a network server via the satellite communication interface.

[0043] In a further embodiment of the invention, the network server has a first communication interface, the first communication interface being operable to communicate with the second and / or third gateway, and the network server has a second communication interface operable to communicate with the first gateway, the second communication interface not being operable to communicate with the second and / or third gateway. In a further aspect of the invention, the second communication interface is suitable for satellite communication. The different communication interfaces are operable to receive messages from the respective gateways and send messages to the respective gateways.

[0044] The object is further achieved by the method according to the invention for early detection of a wildfire. Further advantageous embodiments of the invention are also set forth in the dependent claims.

[0045] The method according to the invention for early detection of a wildfire has seven method steps: the first method step includes detection of a wildfire by a terminal. For this purpose, the terminal has one or more suitable sensors. The second method step includes generation of a signal in a terminal. The signal is generated as a data packet by means of a processor arranged in the terminal. The third method step includes transmission of the signal from the terminal to a second gateway. The transmission to a second gateway is preferably wireless, but wired transmission is also possible. The fourth method step includes receipt of the signal at the second gateway. For this purpose, the second gateway has suitable interfaces and a memory on which the signal is stored. The fifth method step includes forwarding of the signal from the second gateway to a first gateway. In this way, a range extension of LoRaWAN networks is achieved by interposing a multihop network by means of gateways, thus achieving complete compatibility with the LoRaWAN specification. The sixth method step includes receipt of the signal at the first gateway. For this purpose, the first gateway also has suitable interfaces and a memory on which the signal is stored. The seventh method step includes forwarding of the signal from the first gateway to a network server. The network server receives the signal and also has suitable interfaces and a memory on which the signal is stored.

[0046] According to the invention, the forwarding of the signal from the first gateway to a network server is via satellite communication. By means of a connection via a communication satellite, a connection between the first gateway and the network server is also possible over long spatial distances.

[0047] In a development of the invention, the signal is an alarm signal. The alarm signal is generated by a terminal equipped with one or more suitable sensors for detection of a wildfire. Therefore, the alarm signal has the content that a terminal has detected a wildfire.

[0048] In a further embodiment of the invention, the signal is generated immediately after the terminal has captured sensor signals, the analysis of which is indicative of a wildfire. In a further aspect of the invention, the analysis is performed at the terminal. For this purpose, the terminal has an analysis unit which analyzes the sensor signals captured for the presence of a wildfire. If the analysis shows that a wildfire is present, an alarm signal is generated immediately.

[0049] In a further embodiment of the invention, the forwarding of the signal only takes place if the signal is an alarm signal or if the energy storage device of the first gateway has more energy than is needed for two successive forwarding operations by means of satellite communication. The signal may also be a status message of a terminal and / or a gateway, for example. Such a status message will only be forwarded to the network server if the energy storage device of the first gateway has more energy than is needed for two consecutive satellite communications. In this way, sufficient energy is available for an alarm signal. An alarm signal is always forwarded to the network server, provided that sufficient energy is available for forwarding. In a further configuration of the invention, in addition to the forwarding of alarm signals, only signals for testing the satellite communication are transmitted by means of satellite communication.

[0050] In a further embodiment of the invention, the first gateway has a satellite communication interface and a second interface which is different from the satellite communication interface. The second interface provides a connection to a terminal and / or to a further gateway. In a further configuration of the invention, the first gateway has a third interface which is different from the second interface and the satellite communication interface. The third interface provides a connection to a first and / or second gateway. In a development of the invention, the second interface and / or the third interface is suitable for communication with the terminal and / or for communication with the gateway.

[0051] In a further embodiment of the invention, transmission of the message is from the terminal to the second gateway via a single-hop connection. The gateways are coupled to the network server via satellite communication and / or standard Internet Protocol, while the terminals communicate with the respective gateway by radio via LoRa (chirp spread spectrum modulation) or FSK (frequency modulation). Thus, the radio link is a single-hop network in which the terminals communicate directly with one or more gateways, which then forward the data traffic to the network server.

[0052] In a further embodiment of the invention, the transmission of the message from the terminal and the receipt of the message at the second gateway are via different communication channels. In a further embodiment of the invention, the transmission of the message from the first gateway and the transmission of the message from the second gateway to the network server are via different communication channels. This reduces interference due to the use of different frequency ranges.

[0053] In a development of the invention, the network server has two different interfaces, via which the network server receives signals from a terminal. The different communication interfaces are operable to receive messages from the respective gateways and send messages to the respective gateways.

[0054] Exemplary embodiments of the method according to the invention for early detection of a wildfire and the wildfire early detection system according to the invention are shown in the drawings in a schematically simplified manner and are explained in more detail in the following description.

[0055] In the figures:

[0056] Fig. 1 : shows a wildfire early fire detection system, four first gateways,

[0057] Fig. 2: shows a detailed view of the wildfire early detection system according to the invention, two first gateways,

[0058] Fig. 3: shows a wildfire early detection system, a first gateway, three third gateways,

[0059] Fig. 4 a: shows a detailed view of the wildfire early detection system according to the invention, a first gateway, a third gateway,

[0060] Fig. 4 b: shows a detailed view of the wildfire early detection system according to the invention, a third gateway,

[0061] Fig. 5 a: shows an exemplary embodiment of a first gateway, two communication interfaces,

[0062] Fig. 5 b: shows an exemplary embodiment of a first gateway, three communication interfaces, ACK generation unit,

[0063] Fig. 5 c: shows an exemplary embodiment of a first gateway, four communication interfaces, energy conversion and energy storage device,

[0064] Fig 6 a: shows an exemplary embodiment of a second gateway, external power supply,

[0065] Fig. 6 b: shows an exemplary embodiment of a second gateway, internal energy supply through energy conversion and energy storage device,

[0066] Fig. 6 c: shows an exemplary embodiment of a second gateway, three communication interfaces,

[0067] Fig. 7: shows an embodiment of the invention in the LoRaWAN network,

[0068] Fig. 8: shows an embodiment of the invention in the LoRaWAN network,

[0069] Fig. 9: shows an alternative embodiment of the invention in the LoRaWAN network.

[0070] An exemplary embodiment of a wildfire early detection system 10 according to the invention for early detection of a wildfire is shown in Fig. 1 . The wildfire early detection system 10 has a mesh gateway network 1 which utilizes the technology of a LoRaWAN network. The LoRaWAN network has a star-like architecture in which message packets are exchanged between the terminals ED and a central network server NS by means of second gateways G2. The wildfire early detection system 10 has a plurality of terminals ED which are connected to second gateways G2 via a single-hop connection FSK. The second gateways G2 are connected to each other and partly to first gateways SG. The four first gateways SG are connected to the network server NS, exclusively via satellite communication SAT.

[0071] The second gateways G2 and the first gateways G3 are connected to each other via a multi-hop mesh network MHF such that a second gateway G2 does not require direct connection to the network server NS. In this way, a range extension of LoRaWAN networks is achieved by interposing a multi-hop network by means of second gateways G2, thus achieving complete compatibility with the LoRaWAN specification.

[0072] For early detection of a wildfire, a terminal ED first detects a wildfire by the sensor arranged in the terminal ED capturing a corresponding sensor signal. The sensor in the terminal ED is a smoke detector in all of the exemplary embodiments shown herein. The terminal ED analyzes the sensor signal. If the analysis shows that the captured sensor signal is indicative of a wildfire, the terminal ED generates a corresponding alarm signal immediately after the analysis is completed. The alarm signal is transmitted from the terminal ED to a second gateway G2 by means of a single-hop connection FSK and received at the second gateway G2. The second gateway G2 forwards the received alarm signal via a multi-hop connection MHF to a first gateway SG. At the first gateway SG, the alarm signal is also received and forwarded to the network server NS via satellite communication SAT.

[0073] A detailed view of a wildfire early detection system 10 according to the invention is shown in Fig. 2. The wildfire early detection system 10 has a plurality of sensors ED, with eight terminals ED each being connected to a second gateway G2 via a single-hop connection FSK. The second gateways G2 are connected to each other and to first gateways SG. The first gateways SG are connected to the network server NS via satellite communication SAT.

[0074] A further exemplary embodiment of a wildfire early detection system 10 according to the invention for early detection of a wildfire is shown in Fig. 3. The wildfire early detection system 10 has a mesh gateway network 1 . The mesh gateway network 1 according to the LoRaWAN standard also has a star-like architecture. The wildfire early detection system 10 has a plurality of terminals ED which are connected to second gateways G2 via a single-hop connection FSK. The second gateways G2 are connected to each other and partly to a first gateway SG and three border gateways BGD. The first gateway SG is connected to the network server NS via satellite communication SAT. Two border gateways BGD are connected to the network server NS via a wired connection WN, the third border gateway BGD via a wireless Internet connection IP. The first gateway SG is connected to the network server NS via satellite communication SAT.

[0075] For early detection of a wildfire, a terminal ED in turn first detects a wildfire by the sensor arranged in the terminal ED capturing a corresponding sensor signal. The sensor in the terminal ED is a smoke detector in all of the exemplary embodiments shown herein. The terminal ED analyzes the sensor signal. If the analysis shows that the captured sensor signal is indicative of a wildfire, the terminal ED generates a corresponding alarm signal immediately after the analysis is completed. The alarm signal is transmitted from the terminal ED to a second gateway G2 by means of a single-hop connection FSK and received at the second gateway G2. The second gateway G2 forwards the received alarm signal via a multi-hop connection MHF to a first gateway SG or a border gateway BGD, depending on whether the closest gateway is a first gateway SG or a border gateway BGD. At the first gateway SG, the alarm signal is received and forwarded to the network server NS via satellite communication SAT, or the alarm signal is received at the border gateway BGD and forwarded to the network server NS via Internet connection IP or wired connection WN.

[0076] Detailed views of wildfire early detection systems 10 according to the invention are shown in Fig. 4. The wildfire early detection system 10 has a plurality of sensors ED, with eight terminals ED each being connected to a second gateway G2 via a single-hop connection FSK. The second gateways G2 are connected to each other and to a first gateway SG and to a third gateway G3 (Fig. 4 a). The first gateway SG is connected to the network server NS via satellite communication SAT, the third gateway G3 is connected to the network server NS via Internet connection IP and wired connection WN.

[0077] Fig. 4 b shows a detailed view of the wildfire early detection system 10 according to the invention, in which ACK signals S-ACK are exchanged. The wildfire early detection system 10 has a plurality of terminals ED, each connected to a second gateway G2 via a single-hop connection FSK. Two terminals ED are connected to two second gateways G2 each. In contrast to the previous exemplary embodiment (Fig. 4 a), here, an ACK signal from the second gateway G2 connected to the terminal ED is sent to the terminals ED after the second gateway G2 has received a message from the terminal ED. The ACK signal may be a signal for the terminal ED to close a download-receive window and enter the monitoring mode.

[0078] For this purpose, the second gateways G2 have an ACK signal generation unit. The ACK signal (as in “acknowledgment”) is a signal used in data transmission to acknowledge receipt of a message from the terminal ED. This ensures that a message is sent correctly by the terminal ED. Similarly, the terminal ED does not have to be active all the time. Power consumption is reduced and the lifetime of the terminal ED is thus increased.

[0079] Fig. 5 shows three variants of a first gateway SG. The first gateway SG has a self- sufficient energy supply E using, e.g., batteries, capacitors (Fig. 5 a, b) or energy conversion EK by a solar cell and additional storage devices ES (Fig. 5 c). The energy storage device ES is dimensioned such that it may store an amount of energy greater than the energy needed to communicate via the satellite communication interface K2. In particular, the energy storage device ES may store an amount of energy that is more than twice as large as the energy needed to communicate via the satellite communication interface K2. In this and all of the following exemplary embodiments, the energy storage device ES may store an amount of energy three times as large as the energy needed to communicate via the satellite communication interface K2. The forwarding of the signal received from the terminal ED to the network server NS by means of satellite communication SAT only takes place if the signal received from the terminal ED is an alarm signal or the energy storage device ES of the first gateway SG has more energy than is needed for two successive forwarding operations by means of satellite communication SAT. This ensures that sufficient energy for forwarding an alarm signal is available in the first gateway SG. In addition to forwarding alarm signals, only signals for testing satellite communication SAT are transmitted by means of satellite communication SAT.

[0080] By means of the communication interface K1 , the first gateway SG communicates with a terminal ED, by which messages from the terminal ED, in particular measurement data, are received wirelessly as a data packet by means of a single-hop connection FSK via LoRa (chirp spread spectrum modulation) or frequency modulation. In addition, the ACK signal generated in the ACK generation unit ACK is sent to the terminal ED (Fig. 5 b). By means of the communication interface K3, the first gateway SG communicates with the network server NS via an Internet connection IP. Via a multi-hop radio network MHF to other gateways G2, G3, BGD, FGD, MGD, the first gateway SG communicates with other gateways G2, G3, BGD, FGD, MGD by means of the communication interface K4.

[0081] Three variants of a second gateway G2 are shown in Fig. 6. The second gateway G2 also has a self-sufficient energy supply E by means of, e.g., batteries or capacitors (Fig. 6 c), it is also possible to supply energy by means of a mains connection (Fig. 6 a) or an energy supply by means of energy conversion EK by a solar cell and an additional storage device ES (Fig. 6 b). Therefore, the second gateways G2 like the first gateways SG, the third gateways G3 and the terminals ED are able to be operated off-grid. The second gateway G2 has the first communication interface K1. By means of the communication interface K1 , messages from the terminal ED, in particular alarm messages, are received wirelessly from the second gateway G2 as data packets by means of a single-hop connection FSK via LoRa (chirp spread spectrum modulation) or frequency modulation. In addition, the ACK signal generated in the ACK generation unit ACK, which is optionally arranged in the second gateway G2, is optionally sent to the terminal ED.

[0082] Via a multi-hop radio network MHF to other gateways G2, G3, BGD, FGD, MGD, the first gateway SG communicates with other gateways G2, G3, BGD, FGD, MGD by means of the communication interface K4.

[0083] In the embodiment of the second gateway G2 as the border gateway BGD, the gateway G2 (Fig. 6 c) has the communication interface K3, by which messages from the terminal ED are sent to a network server NS via an Internet connection IP.

[0084] In order to receive the messages and in particular alarm messages from the mesh gateway network 1 , the network server NS has a first communication interface, the first communication interface being operable to communicate with the second and / or the third gateway G2, G3. In addition, the network server NS has a second communication interface which is operable to communicate with the first gateway SG via satellite communication SAT. In particular, the second communication interface is not operable to communicate with a second and / or third gateway G2, G3.

[0085] Fig. 7 shows an embodiment of the invention, in which the third gateways G3 and the second gateways G2 are grouped together in a device MGD. These so-called mesh gateways MGDn are a combination of a third gateway G3 and a second gateway G2. The mesh gateways MGDn communicate with each other by means of the multi-hop radio network MHF, and at least one mesh gateway MGD is connected to the network server NS via the standard Internet Protocol IP.

[0086] While, in a conventional standard LoRa radio network, terminals EDn are directly coupled to second gateways G2 via a single-hop radio link, the gateways Gn are divided into multiple second gateways G2 and third gateways G3. The second gateways G2 now talk to each other via a multi-hop radio network MHF, while at least one of the second gateways G2 also talks to a third gateway G3. Then, the latter sends the data directly to the network server NS by means of an Internet Protocol IP. Alternatively and in a particularly advantageous embodiment, the second gateways G2 and the third gateways G3 are grouped together in one device, namely in so-called “mesh gateways” MGD. Again, the integrated second gateways G2 talk to each other by means of a multi-hub radio network MHD, while the mesh gateways MGD4, MGD6, MGD7 are connected to the network server NS, each via an integrated third gateway G3 via the standard Internet Protocol IP.

[0087] A mesh gateway MGDn has an ACK signal generation unit ACK and, after receiving a message from a terminal EDn, sends S-ACK an ACK signal to the terminal EDn having sent the message. This ensures that a message from the terminal EDn to a mesh gateway MGDn is correctly sent to the mesh gateway MGDn. The terminal EDn does not have to have a permanently active download-receive window and therefore be permanently active, as with a class C terminal, but can also be, for example, a class A or B terminal EDn in accordance with the LoRaWAN specification. Power consumption and the lifetime of the terminal EDn are thus increased. Failure of a terminal EDn due to internal errors is avoided.

[0088] Fig. 8 shows an embodiment of the invention, in which the first gateways SG and the second gateways G2 are grouped together in a mesh gateway MGD. Here, the second gateways G2 integrated in the mesh gateway MGDn talk to each other via a multi-hop radio network MHD, while the mesh gateways MGD4, MGD6, MGD7 are connected to the network server NS, each via an integrated first gateway SG via a satellite connection SAT.

[0089] Fig. 9 schematically shows a further embodiment of the LoRaWAN network 1 , into which the wildfire early detection system 10 according to the invention is integrated. The network 1 has a plurality of sensors ED connected to gateways via a single-hop connection FSK. The second gateways G2 are front-end gateways FGDn. The front-end gateways FGDn are connected to each another and partly to border gateways BGDn. The border gateways BGDn are connected to the network server NS via a wireless connection by means of the Internet Protocol IP. The front-end gateways FGDn and the border gateways BGDn are connected to each another via a multi-hop mesh network MHF, so that a front-end gateway FGDn does not require a direct connection to the network server NS. In this way, a range extension of LoRaWAN networks is achieved by interposing a multi-hop network by means of front-end gateways FGDn between terminals ED and network server NS, thus achieving complete compatibility with the LoRaWAN specification.

[0090] LIST OF REFERENCE NUMERALS

[0091] 1 mesh gateway network

[0092] 10 wildfire early detection system

[0093] ED, EDn terminals / sensors

[0094] SG first gateway

[0095] G2 second gateway

[0096] G3 third gateway

[0097] NS network server

[0098] IP Internet Protocol

[0099] BGD, BGDn border gateways

[0100] FGD, FGDn front-end gateways

[0101] MHF multi-hop radio network

[0102] MDG, MDGn mesh gateways

[0103] FSK FSK modulation, single-hop connection

[0104] WN wired connection

[0105] E energy supply

[0106] ES energy storage device

[0107] EK energy conversion

[0108] K1 , K2, K3, K4 communication interface

[0109] SAT satellite, satellite connection

[0110] W forest

Claims

CLAIMS1. A wildfire early detection system (10) comprising a mesh gateway network(1 ), having• a network server (NS),• a first gateway (SG),• a second gateway (G2), and• multiple terminals (ED), characterized in that the first gateway (SG) has a first communication interface (K2) to a communication satellite and a further communication interface (K1 , K3, K4) to other gateways (SG, G2, G3) and / or terminals (ED) and / or the network server (NS) of the mesh gateway network (1 ), and the second gateway (G2) has different communication interfaces than the first gateway (SG).

2. The wildfire early detection system (10) according to claim 1 , characterized in that the second gateway (G2) communicates exclusively with other gateways (SG, G2, G3) and / or terminals (ED) and / or the network server (NS).

3. The wildfire early detection system (10) according to claim 1 or 2, characterized in that the second gateway (G2) is unsuitable for communication with a communication satellite.

4. The wildfire early detection system (10) according to any one or more of the preceding claims, characterized in that the mesh gateway network (1 ) comprises an LPWAN, and / or the mesh gateway network (1 ) comprises a LoRaWAN.

5. The wildfire early detection system (10) according to any one or more of the preceding claims, characterized in that the mesh gateway network (1 ) has a third gateway (G3), which has different communication interfaces (K1 , K3, K4) than the first gateway (SG) and the second gateway (G2).

6. The wildfire early detection system (10) according to claim 5, characterized in that the second gateway (G2) exclusively communicates directly with other gateways (SG, G1 , G2) and terminals (ED) of the mesh gateway network (1 ), and the third gateway (G3) communicates with the network server (NS).

7. The wildfire early detection system (10) according to any one or more of the preceding claims, characterized in that the third gateway (G3) communicates with other gateways (SG, G2, G3) of the mesh gateway network (1 ) and / or terminals (ED).

8. The wildfire early detection system (10) according to any one or more of the preceding claims, characterized in that the second and / or the third gateway (G2, G3) has a communication interface (K3) which provides an Internet connection (IP) to the network server (NS).

9. The wildfire early detection system (10) according to any one or more of the preceding claims, characterized in that the terminals (ED) and / or the second gateways (G2) and / or the third gateways (G3) and / or the first gateways (SG) have a self-sufficient energy supply (E).

10. The wildfire early detection system (10) according to claim 9,characterized in that the self-sufficient energy supply (E) comprises an energy storage device (ES) and / or an energy conversion device (EK).11 . The wildfire early detection system (10) according to any one or more of the preceding claims, characterized in that the terminals (ED) and the second gateways (G2) and / or the third gateways (G3) are operated off-grid.

12. The wildfire early detection system (10) according to claim 11 , characterized in that the ACK signal generation unit (ACK) has a processor and a memory.

13. The wildfire early detection system (10) according to any one or more of the preceding claims, characterized in that the second gateways (G2) of the mesh gateway network (1 ) are front-end gateways (FGD) and / or the third gateway (G3) is a border gateway (BGD).

14. The wildfire early detection system (10) according to claim 13, characterized in that the second gateway (G2) has the ACK signal generation unit (ACK).

15. The wildfire early detection system (10) according to any one or more of the preceding claims, characterized in that the first gateways (SG) and / or the second gateways (G2) and / or the third gateways (G3) have an ACK signal generation unit (ACK).

16. The wildfire early detection system (10) according to claim 14 or 15, characterized in that the second gateway (G2) has a first front-end gateway communication interface (K1 )for communication with a terminal (ED) and a second front-end gateway communication interface (K2) for communication with another first (SG), second (G2) and / or a third gateway (G3).

17. The wildfire early detection system (10) according any one or more of claims 13 to 16, characterized in that each second gateway (G2) is suitable for point-to-point wireless communication with a plurality of terminals (ED) using single-hop (FSK) LoRa or FSK radio using the LoRaWAN protocol.

18. The wildfire early detection system (10) according to any one or more of claims 14 to 17, characterized in that the second gateway (G2) and the third gateway (G3) are combined with a plurality of mesh gateway devices (MGD), and at least one of the mesh gateway devices (MGD) does not have a direct IP connection (IP) to the network server (NS).

19. The wildfire early detection system (10) according to any one or more of claims 14 to 18, characterized in that the third gateway (G3) is provided for communication with the network server (NS) by means of a standard IP connection (IP) and using the LoRaWAN protocol.

20. The wildfire early detection system (10) according to claim 19, characterized in that the third gateway (G3) has a first border gateway communication interface (K3) for communication with a network server (NS), and a second border gateway communication interface (K2) for communication with a second gateway (G2).

21. The wildfire early detection system (10) according to any one or more of claims 14 to 20,characterized in that a second gateway (G2) is integrated with a third gateway (G3) in a mesh gateway (MGD).

22. The wildfire early detection system (10) according to any one or more of claims 14 to 21 , characterized in that the mesh gateway network (1 ) is a wireless multi-hop radio network.

23. The wildfire early detection system (10) according to any one or more of claims 14 to 22, characterized in that the first gateway (SG) has an energy storage device (ES) which may store an amount of energy greater than the energy needed to communicate via the satellite communication interface (K2).

24. The wildfire early detection system (10) according to claim 23, characterized in that the energy storage device (ES) may store an amount of energy that is more than twice as large as the energy needed to communicate via the satellite communication interface (K2).

25. The wildfire early detection system (10) according to any one or more of the preceding claims, characterized in that the network server (NS) has a first communication interface; wherein the first communication interface is operable to communicate with the second and / or third gateway (G2, G3), and the network server (NS) has a second communication interface operable to communicate with the first gateway (SG), wherein the second communication interface is not operable to communicate with the second and / or third gateway (G2, G3).

26. The wildfire early detection system (10) according to claim 25, characterized in that the second communication interface is suitable for satellite communications (SAT).

27. A method for early detection of a wildfire, having the steps of• detection of a wildfire by a terminal (ED),• generation of a signal in a terminal (ED),• transmission of the signal from the terminal (ED) to a second gateway (G2),• receipt of the signal at the second gateway (G2),• forwarding of the signal from the second gateway (G2) to a first gateway (SG),• receipt of the signal at the first gateway (SG),• forwarding of the signal from the first gateway (SG) to a network server (NS), characterized in that the forwarding of the signal from the first gateway (SG) to a network server (NS) is via satellite communication (SAT).

28. The method for early detection of a wildfire according to claim 27, characterized in that the signal is an alarm signal.

29. The method for early detection of a wildfire according to claim 27 or 28, characterized in that the signal is generated immediately after the terminal (ED) has captured sensor signals, the analysis of which is indicative of a wildfire.

30. The method for early detection of a wildfire according to claim 29, characterized in that the analysis is performed at the terminal (ED).31 . The method for early detection of a wildfire according to any one or more of claims 27 to 30,characterized in that the forwarding of the signal only takes place if the signal is an alarm signal or if the energy storage device (ES) of the first gateway (SG) has more energy than is needed for two successive forwarding operations by means of satellite communication (SAT).

32. The method for early detection of a wildfire according to any one or more of claims 27 to 31 , characterized in that in addition to the forwarding of alarm signals, only signals for testing the satellite communication (SAT) are transmitted by means of satellite communication (SAT).

33. The method for early detection of a wildfire according to any one or more of claims 27 to 32, characterized in that the first gateway (SG) has a satellite communication interface (K2) and a second interface (K1 ) which is different from the satellite communication interface (K2).

34. The method for early detection of a wildfire according to claim 33, characterized in that the first gateway (SG) has a third interface (K3) different from the second interface (K1 ) and the satellite communication interface (K2).

35. The method for early detection of a wildfire according to claim 33 or 34, characterized in that the second interface (K1 ) and / or the third interface (K3) is suitable for communication with the terminal (ED) and / or for communication with the gateway (G2, G3).

36. The method for early detection of a wildfire according to any one or more of claims 27 to 35, characterized in that the transmission of the message from the terminal (ED) to the second gateway (G2) is via a single-hop connection (FSK).

37. The method for early detection of a wildfire according to any one or more of claims 27 to 36, characterized in that the second gateway (G2) forwards the message to a third gateway (G3), a first gateway (SG) and / or the network server (NS).

38. The method for early detection of a wildfire according to any one or more of claims 27 to 37, characterized in that the transmission of the message from the terminal (ED) and the receipt of the message at the second gateway (G2) are via different communication channels.

39. The method for early detection of a wildfire according to any one or more of claims 27 to 38, characterized in that the transmission of the message from the first gateway (SG) and the transmission of the message from the second gateway (G2) to the network server (NS) are via different communication channels.

40. The method for early detection of a wildfire according to any one or more of claims 27 to 39, characterized in that the network server (NS) has two different interfaces via which the network server (NS) receives signals from a terminal (ED).

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