SYSTEM AND METHOD FOR EARLY DETECTION OF A FOREST FIRE

Abstract

The invention relates to a forest fire early detection system comprising a network server, a first gateway, and several terminal devices, wherein the terminal device has a first communication interface to a first gateway of the forest fire early detection system and a second communication interface to an external device. The invention further relates to a method for the early detection of a forest fire using a forest fire early detection system, comprising the process steps of detecting a forest fire from the terminal device, generating a signal in the terminal device, first transmitting the signal from the terminal device via a first communication interface of the terminal device, waiting for the receipt of a response signal on the terminal device, and second transmitting the signal from the terminal device via a second communication interface of the terminal device. The invention also relates to an emergency communication terminal for a forest fire early detection system comprising a sensor, wherein the sensor is suitable for detecting a forest fire, a power supply device, a first communication interface and a second communication interface, wherein the first communication interface is different from the second communication interface.

Description

[0001] The invention relates to a forest fire early detection system comprising a network server, a first gateway, and a plurality of terminal devices. The terminal device has a first communication interface to a first gateway of the forest fire early detection system and a second communication interface to an external device. The invention further relates to a method for the early detection of a forest fire using a forest fire early detection system, comprising the method steps of detecting a forest fire by the terminal device, generating a signal in a terminal device, first sending the signal from the terminal device via a first communication interface of the terminal device, waiting for receipt of a response signal on the terminal device, and second sending the signal from the terminal device via a second communication interface of the terminal device.

[0002] The invention also relates to an emergency communication terminal for a forest fire early detection system comprising a sensor, wherein the sensor is suitable for detecting a forest fire, a power supply device, a first communication interface and a second communication interface, wherein the first communication interface is different from the second communication interface. State of the art

[0003] Systems for the early detection of forest fires are well known. The area to be monitored is monitored using optical sensors that can detect smoke columns generated by a forest fire. These sensors, for example, include rotating cameras, but they have the disadvantage of being less effective at night and prone to false detections, such as dust clouds caused by agricultural activities. Furthermore, optical systems can usually only detect forest fires once the forest fire is already advanced and the smoke columns are visible over greater distances.

[0004] It makes more sense to monitor the area using a number of inexpensive, mass-produced sensors that operate using optical smoke and / or gas detection. The sensors are distributed throughout the area and transmit data to a base station via radio link.

[0005] Such a system for the early detection of forest fires is presented in US 2008 / 0309502 A1. In the event of a fire alarm, a sensor transmits information to a nearby control terminal, which then triggers an alarm using a long-range radio frequency signal.

[0006] This system has the disadvantage that the control terminal triggers the alarm and requires a powerful RF unit. The sensors require a GPS unit that continuously transmits a signal to the control terminal. Therefore, the sensors consume a lot of power, and the lifespan of the sensors' power sources (batteries) is limited. Task

[0007] It is therefore an object of the present invention to provide a forest fire early detection system and a method for the early detection of a forest fire, which operate reliably, can be expanded as required, and are cost-effective to install and maintain. Description of the invention

[0008] The object is achieved by means of the forest fire early detection system according to claim 1. Advantageous embodiments of the invention are set out in the subclaims.

[0009] The forest fire early detection system according to the invention comprises a network server, a first gateway, and several end devices. One end device has a sensor unit for detecting a forest fire. The first gateways are responsible for receiving data from the end devices and forwarding it to the network server. They serve as a bridge between the end devices and the network server and enable the connection of end devices in the field with the backend system. The network server is the core of the forest fire 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 and the configuration of network parameters such as bandwidth, channels, and transmission power. The network server communicates via various protocols (e.g., REST, MQTT, etc.) with an application that is operated, for example, as an application in the cloud.

[0010] According to the invention, the terminal device has a first communication interface to the first gateway and a second communication interface to an external device. An external device within the meaning of the invention is a device that is not part of the terminal device, in particular, is not arranged as a structural unit with the terminal device. In a further development, the external device is not part of the forest fire early detection system, which has a network server, a first gateway, a second gateway, and a plurality of terminal devices. The external device can be, for example, a receiver of a radio network, an application server, a backup server, a communications relay, or a communications satellite.

[0011] Using the first communication interface, messages can be sent to and received from a first gateway. Messages can be forwarded from the end device to the network server via the first gateway, optionally via a standard internet connection and / or a wired connection.

[0012] The second communication interface can be used to establish a connection to an external device, via which messages from the terminal device can optionally be sent to the network server. A connection via a communications satellite enables a connection between the terminal device and the external device even over large distances.

[0013] In a further development of the invention, the second communication interface is suitable for using wireless communication technology. In particular, the second communication interface is suitable for wireless communication with the external device. The external device can therefore be located at a large spatial distance from the terminal device. In addition, the spatial distance between the external device and the terminal device does not have to be constant, but can vary.

[0014] In a further embodiment of the invention, the first communication interface is different from the second communication interface of the terminal device. In a further embodiment of the invention, the first communication interface is suitable for using a communication technology different from the communication technology usable by the second communication interface and / or a communication protocol different from the communication protocols usable by the second communication interface. In a further aspect of the invention, the second communication interface is suitable for communicating with a communications satellite.

[0015] Using the first communication interface, messages can be sent to and received from gateways via a single-hop connection.

[0016] The second communication interface to a communications satellite can be used to establish a connection to a communications satellite, via which data packets can be sent from the terminal device to the network server. The two communication interfaces therefore use different communication protocols and are therefore also structured differently.

[0017] In a further development of the invention, the first communication interface is unsuitable for communicating with a communications satellite. Using the first communication interface, messages can be sent to and received from gateways via a single-hop connection using a direct radio connection.

[0018] In a further embodiment of the invention, the terminal device is suitable for communicating via the communications satellite with a gateway of the forest fire early warning system or the network server. Communication between the terminal device and a gateway via a communications satellite is direct, i.e., without any further intermediate stations (a single-hop connection). Communication between the terminal device and a network server via a communications satellite is also a direct single-hop connection.

[0019] In an advantageous embodiment of the invention, the terminal device has a self-sufficient power supply and is designed for off-grid use. To enable installation and operation of the terminal device even in inhospitable and, in particular, rural areas far from any power supply, the terminal device is equipped with a self-sufficient power supply. The power supply can be provided, for example, by energy storage devices – including rechargeable ones.

[0020] In a further embodiment of the invention, the self-sufficient energy supply comprises an energy storage device and / or energy conversion device. In particular, the energy supply via solar cells is worthy of mention, in which the energy conversion from light to electrical energy takes place. The electrical energy is typically stored in an energy storage device to ensure the energy supply even during times of low solar radiation (e.g., at night). In a further embodiment of the invention, the terminal device is operated off-grid. The self-sufficient energy supply enables operation without a power supply from external devices.

[0021] In a further embodiment of the invention, the energy storage device can store more energy than is consumed by a standard communication to the first gateway and by a standard communication to the communications satellite. A standard communication in the context of this document is a communication to report a forest fire. The terminal device therefore has sufficient energy reserves to perform further communication processes, e.g., send another message to a gateway or the network server, without the energy storage device having to be recharged, e.g., by solar cells.

[0022] In a further development of the invention, the energy storage device can store an amount of energy that is more than twice the energy required to communicate via the second communication interface. The terminal device therefore has sufficient energy reserves to perform further processes, in particular further communication with a network server via the second communication interface.

[0023] In a further embodiment of the invention, the energy conversion device comprises a solar cell, a wind turbine with a generator, and / or is suitable for converting ambient energy into electrical energy. The generated electrical energy is optionally stored in an energy storage device (e.g., a battery, a capacitor). Piezo elements arranged in stacks generate an electrical voltage when temperatures change (e.g., during day and night cycles), which can also be stored in an energy storage device.

[0024] In a further embodiment of the invention, the first communication interface is suitable for sending and receiving LPWAN messages. LPWAN describes a class of network protocols for connecting low-energy devices, such as battery-operated sensors located in a terminal device, to a network server. The protocol is designed to achieve a long range and low energy consumption of the terminal devices at low operating costs. LoRaWAN requires particularly low energy consumption. LoRaWAN networks implement a star-shaped architecture using gateways to transmit message packets between the terminal devices and the central network server. The gateways are connected to the network server, while the terminal devices communicate with a gateway via a wireless connection using LoRa.

[0025] In an advantageous embodiment of the invention, the shortest communication route leads from the terminal device via the first gateway to the network server via at least one second gateway. The second gateway has a communication interface to a network server, as well as communication interfaces to other gateways and / or terminal devices via a wireless or wired connection.

[0026] In a further embodiment of the invention, the second gateway is different from the first gateway. In a further development of the invention, the second gateway has different communication interfaces than the first gateway. The second gateway has a communication interface to a network server, as well as communication interfaces to other gateways and / or terminal devices via a wireless or wired connection. The first gateway has communication interfaces to other gateways and / or terminal devices via a wireless or wired connection.

[0027] In a further embodiment of the invention, the second gateway is suitable for communicating directly with the network server, whereas the first gateway is unsuitable for communicating directly with the network server. The first gateway does not have a communication interface to a network server, but only communication interfaces to other gateways and / or terminal devices via wireless or wired connections. In particular, the first gateways do not have a single-hop connection to a network server.

[0028] In a further embodiment of the invention, the first and / or second gateway is unsuitable for communication with a communications satellite. Only the terminal device has a single-hop connection to a network server via a communications satellite. Communication between the gateways can take place via 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 meshed multi-hop network and can thus forward the data from the terminal devices to the network server. The connection between the second gateway and the network server is wireless or wired.

[0029] In a further embodiment of the invention, the mesh gateway network comprises an LPWAN, where the LPWAN comprises a LoRaWAN. LPWAN describes a class of network protocols for connecting low-energy devices such as battery-operated sensors to a network server. The protocol is designed to achieve a long range and low energy consumption of the end devices at low operating costs. LoRaWAN requires particularly low energy consumption. LoRaWAN networks implement a star-shaped architecture using gateway message packets between the end devices and the central network server. The gateways are connected to the network server, while the end devices communicate wirelessly via LoRa with a second and / or first gateway.

[0030] In a further embodiment of the invention, the second and / or third gateway has a communication interface that provides an internet connection to the network server. The internet connection is a wireless point-to-point connection, preferably using a standard internet protocol.

[0031] In an advantageous embodiment of the invention, the gateways have a self-sufficient power supply. To enable installation and operation of gateways even in inhospitable and, in particular, rural areas far from power supplies, the gateways are equipped with a self-sufficient power supply. The power supply can be provided, for example, by energy storage devices – including rechargeable ones.

[0032] In a further embodiment of the invention, the self-sufficient energy supply comprises an energy storage device and / or energy conversion device. In particular, the energy supply via solar cells is worthy of mention, in which the energy conversion from light to electrical energy takes place. The electrical energy is typically stored in an energy storage device to ensure the energy supply even during times of low solar radiation (e.g., at night). In a further embodiment of the invention, the gateways are operated off-grid. The self-sufficient energy supply enables operation without a power supply from external devices.

[0033] In a further embodiment of the invention, the first gateways have an ACK signal generation unit. An ACK generation unit within the meaning of this invention is a sub-server unit integrated into a second gateway, which assumes functionalities and tasks provided for the network server according to the LoRaWAN protocol. ACK signals within the meaning of this invention are messages, commands, and functions stored on the first gateway or generated by a first gateway. The ACK signal (from the English "acknowledgement") generated by the ACK generation unit is a signal used during data transmission to confirm receipt. This ensures that a message has been sent correctly. Likewise, the terminal device does not have to be constantly active. Power consumption is reduced, and the service life of the terminal device is thus increased.

[0034] In a further development of the invention, the ACK signal generation unit comprises a processor and a memory. The processor and memory are standard components and therefore inexpensive to manufacture.

[0035] The object is further achieved by means of the inventive method for the early detection of a forest fire using a forest fire early detection system. Further advantageous embodiments of the invention are also set forth in the subclaims.

[0036] The method for early detection of a forest fire according to the invention comprises five steps: In the first step, a forest fire is detected by a terminal device. The terminal device has one or more suitable sensors for this purpose.

[0037] In the second process step, a signal is generated in a terminal device. The signal is generated as a data packet by a processor located in the terminal device.

[0038] In the third step, the signal is first transmitted from the terminal device via a first communication interface of the terminal device. The initial transmission is preferably wireless, but wired transmission is also possible. In the fourth step, the terminal device waits for a response signal to be received. The terminal device has suitable interfaces and a memory for storing the signal.

[0039] The response signal is a message from an external device of the forest fire early detection system, e.g., a network server, to the terminal device and indicates that the signal has been received by the external device. The external device generates the response signal immediately after receiving the signal from the terminal device and sends the response signal optionally via a direct connection to the terminal device and / or also optionally via a multi-hop connection using gateways of the forest fire early detection system to the terminal device that sent the signal.

[0040] In the fifth step, the signal is sent a second time from the terminal device via a second communication interface of the terminal device. The second transmission via the second communication interface of the terminal device only occurs if the terminal device does not receive a response message. This is the case, for example, if the first transmission of the signal via the first communication interface of the terminal device to the external device was unsuccessful, i.e. the signal did not reach the external device. The reason for this could be, for example, a faulty first communication interface of the terminal device, a faulty communication interface of the external device, or a transmission error. Furthermore, the transmission of the response message from the external device itself could be disrupted.

[0041] For sending a signal, e.g., an alarm message upon detection of a forest fire by the terminal device, the first transmission via the first communication interface is preferred according to the invention. The second transmission via the second communication interface only occurs in cases where it is unclear whether the signal has reached the external device. The second transmission via the second communication interface provides a redundant option for sending messages from the terminal device, particularly in emergencies. The method according to the invention ensures that a signal from the terminal device, in particular an alarm signal, reaches the external device.

[0042] In a further development of the invention, the signal is sent via a first communication interface of the terminal device to a first gateway of the forest fire early detection system. The first transmission of the signal from the terminal device to the first gateway occurs via a single-hop connection. The first gateways are connected to the external device via satellite communication or standard Internet Protocol, while the terminal devices communicate wirelessly with the respective gateway via LoRa (frequency spread spectrum modulation) or FSK (frequency modulation). The wireless connection is thus a single-hop network in which the terminal devices communicate directly with one or more gateways, which then forward the data traffic to the external device.

[0043] In an optional embodiment of the invention, the first transmission of the signal occurs via the first communication interface of the terminal device to a network server of the forest fire early detection system. This enables direct communication between the terminal device and the network server if communication via the network gateways is not possible, for example, for technical reasons.

[0044] In a further aspect of the invention, the signal contains information about a detected forest fire. In particular, the signal contains information about which terminal device(s) detect a forest fire. This makes it possible to locate the forest fire.

[0045] In a further embodiment of the invention, the terminal device waits for the receipt of a response signal over a specified time interval. In a further development of the invention, the time interval is longer than the average duration between the first transmission of the signal and the receipt of the response signal. For this purpose, the terminal device optionally determines the time interval between each first transmission of a signal via the first communication interface and each receipt of a corresponding response signal on the terminal device, and the average of the time intervals is calculated and stored.

[0046] In a further embodiment of the invention, the time interval between reception of the signal and non-reception of the response signal is greater by a factor of 2, preferably by a factor of 1.5, and particularly preferably by a factor of 1.25 than the duration between reception of a previously received signal and reception of the response signal from the network server associated with this previously received signal. This ensures that the connection to the network server via a communications satellite is only used when an IP connection and / or wired connection is not possible.

[0047] In an advantageous embodiment of the invention, the second transmission occurs via the terminal device's second communication interface, which is suitable for communicating with a communications satellite. Using the second communication interface to a communications satellite, a connection to a communications satellite can be established, via which signals from the terminal device can be sent to an external device, preferably a network server. Using a connection via a communications satellite, a connection from the terminal device to the network server is possible even over large distances, as an alternative to communication via the first communication interface.

[0048] In a further development of the invention, the second transmission of the signal takes place via the second communication interface of the terminal device to a network server of the forest fire early detection system. The signal generated by the terminal device is sent directly to the network server of the forest fire early detection system via the communication satellite. By connecting via a communication satellite, a connection from the terminal device to the network server is possible, even over large distances, as an alternative to communication via the first communication interface.

[0049] In a further embodiment of the invention, the response signal is an acknowledgement of receipt from the network server. The response signal from the network server confirms to the terminal device that the signal from the terminal device has been received by the network server. This ensures that the signal was sent correctly by the terminal device. The response signal can be a signal for the terminal device to close a download / receive time window and enter monitoring mode. Likewise, the terminal device does not need to be constantly active. The power consumption of the terminal device is reduced, and its operating time is increased.

[0050] In a further embodiment of the invention, the second transmission of the signal via the second communication interface of the terminal device only occurs if the signal is an alarm signal or if the terminal device's energy storage contains more energy than is required for two consecutive transmissions via satellite communication via the second communication interface. This ensures that sufficient energy is available in the terminal device to forward an alarm signal. To test satellite communication, in addition to forwarding alarm signals, signals are optionally also sent via the second communication interface.

[0051] In an advantageous embodiment of the invention, the second transmission of the signal occurs only via the second communication interface of the terminal device if the signal was previously transmitted by the terminal device via the first communication interface. For the transmission of a signal, e.g., an alarm message upon detection of a forest fire by the terminal device, the first transmission via the first communication interface is therefore preferred.

[0052] In a further development of the invention, the second transmission of the signal only takes place via the second communication interface of the terminal device to the network server if no confirmation of receipt of the sent signal was previously received from the network server on the terminal device. The second transmission via the second communication interface of the terminal device only takes place if the terminal device does not receive an confirmation of receipt. This is the case, for example, if the first transmission of the signal via the first communication interface of the terminal device to the network server was unsuccessful, i.e. the signal did not reach the network server. The reason for this could be, for example, a faulty first communication interface of the terminal device, a faulty communication interface of the external device or a transmission error. Furthermore, the transmission of the confirmation of receipt may be disrupted by the external device itself.

[0053] In a further aspect of the invention, the second transmission of the signal only occurs via the second communication interface to the network server if no confirmation of receipt of the transmitted signal was previously received from the network server via a communication interface on the terminal device that is different from the second communication interface. The second transmission via the second communication interface only occurs in cases where it is unclear whether the signal has reached the external device. The second transmission via the second communication interface provides a redundant option for sending messages from the terminal device, particularly in emergencies. The method according to the invention ensures that a signal from the terminal device, in particular an alarm signal, reaches the external device.

[0054] In a further embodiment of the invention, after a forest fire is detected, a software program for selecting the communication interface is started. The software program is executed on the terminal device. The terminal device optionally has a controller implemented as a microcomputer and connected to a memory.

[0055] In a further aspect of the invention, a software program for selecting the communication interface is started immediately after analyzing the signal on the terminal device. The software program for selecting the communication interface preferably selects a communication interface by means of which communication with the network server does not take place via a communication satellite, preferably the first communication interface. Communication with the network server via the first communication interface preferably takes place via a multi-hop connection and / or a single-hop connection.

[0056] The object is further achieved by means of the emergency communication terminal according to the invention for a forest fire early detection system. Further advantageous embodiments of the invention are also set forth in the subclaims.

[0057] The emergency communication terminal according to the invention comprises a sensor, wherein the sensor is suitable for detecting a forest fire, a power supply device, a first communication interface, and a second communication interface, wherein the first communication interface is different from the second communication interface. The sensor for detecting a forest fire is, for example, an optical sensor, gas sensor, or temperature sensor, or a combination of the aforementioned sensors. The power supply device enables a self-sufficient power supply of the terminal and comprises, for example, batteries, capacitors, and / or energy conversion, e.g., a solar cell with additional energy storage.

[0058] Using the first communication interface, signals can optionally be sent to and received from gateways via a single-hop connection. Using the second communication interface, signals can optionally be sent to and received from the network server of the forest fire early detection system, preferably via a direct connection. The two communication interfaces use different communication protocols and are therefore structured differently.

[0059] In a further development of the invention, the first communication interface is suitable for communicating with a gateway of the forest fire early detection system. Messages can be sent to and received from a first gateway via the first communication interface. Messages can be forwarded from the terminal device to the network server via the first gateway, optionally via a standard internet connection and / or a wired connection.

[0060] In a further embodiment of the invention, the second communication interface is suitable for communicating with a communication device external to the forest fire early warning system. The external device can be, for example, a radio network receiver, an application server, a backup server, a communication relay, or a communication satellite.

[0061] In an advantageous embodiment of the invention, the second communication interface is suitable for communicating with a communications satellite. Using the second communication interface to a communications satellite, a connection can be established to a communications satellite, via which data packets can be sent from the terminal device to the network server. The first communication interface and second communication interface therefore use different communication protocols and are therefore also structured differently.

[0062] In a further embodiment of the invention, the emergency communication terminal comprises a controller capable of executing a software program that selects the communication interface to be used for communication. For this purpose, the terminal comprises the controller, which is implemented as a microcomputer and is optionally connected to a memory.

[0063] In a further embodiment of the invention, the controller is suitable for controlling the communication interfaces separately. The two communication interfaces are controlled in such a way that either a signal is sent via the first communication interface at a first point in time or a signal is sent via the second communication interface at a second point in time. No signal is sent via either communication interface at the same time.

[0064] In a further advantageous embodiment of the invention, the power supply device of the emergency communication terminal has an energy storage device capable of storing more energy, preferably more than 1.5 times as much energy, and particularly preferably more than twice as much energy, than is required for communication via the second communication interface. This ensures that sufficient energy is available in the terminal for transmitting a signal, in particular an alarm signal. To test satellite communication, in addition to transmitting alarm signals, signals are optionally also sent via the second communication interface.

[0065] In a further development of the invention, the signal is an alarm signal. The alarm signal is generated by a terminal device that has one or more suitable sensors for detecting a forest fire. The alarm signal therefore indicates that a terminal device has detected a forest fire.

[0066] In a further embodiment of the invention, the signal is generated immediately after the terminal device has detected sensor signals whose analysis indicates a forest fire. In a further aspect of the invention, the analysis is performed on the terminal device. The terminal device has an analysis unit that analyzes the detected sensor signals for the presence of a forest fire. If the analysis indicates that a forest fire is present, an alarm signal is generated immediately.

[0067] In a further embodiment of the invention, in addition to sending alarm signals, only signals for testing satellite communication are sent via satellite communication. Sending, for example, low-priority status messages from the terminal device places unnecessary strain on satellite communication and generates high costs. Such low-priority messages can also be sent via the first communication interface.

[0068] In a further embodiment of the invention, the message is sent from the end device to the first gateway via a single-hop connection. The gateways are connected to the network server via a multi-hop connection and standard Internet Protocol, while the end devices communicate wirelessly with the respective gateway via LoRa (frequency spread spectrum modulation) or FSK (frequency modulation). The wireless connection is thus a single-hop network, in which the end devices communicate directly with one or more gateways, which then forward the data traffic to the network server.

[0069] In a further development of the invention, the network server has two different interfaces through which the network server receives signals from a terminal device. The different communication interfaces are suitable for receiving messages from the respective gateways and sending messages to the respective gateways.

[0070] Embodiments of the forest fire early detection system according to the invention, the method according to the invention for the early detection of a forest fire and the emergency communication terminal according to the invention are shown in simplified schematic form in the drawings and are explained in more detail in the following description.

[0071] They show: Fig. 1: Forest fire early warning system, four second gateways, two emergency communication terminals Fig. 2: Detailed view of the forest fire early detection system according to the invention, an emergency communication terminal Fig. 3: Detailed view of the forest fire early detection system according to the invention, exchange of ACK messages Fig. 4: Example of a terminal that can be used as an emergency communication terminal Fig. 5: Sequence diagram of the LoRa radio network Fig. 6: Sequence diagram of the LoRaWAN mesh gateway network, connection via communication satellites Fig. 7: Sequence diagram of the LoRaWAN mesh gateway network, connection via communication satellites after a time interval has elapsed

[0072] An embodiment of an inventive forest fire early detection system 10 for the early detection of a forest fire shows Fig. 1. The forest fire early detection system 10 comprises a mesh gateway network 1 that uses LoRaWAN network technology. The LoRaWAN network has a star-shaped architecture in which message packets are exchanged between the end devices ED and a central network server NS via gateways G1 and G2. The forest fire early detection system 10 comprises a plurality of end devices ED connected to second gateways G2 via a single-hop connection FSK. The first gateways G1 are interconnected and partially connected to second gateways G2. The four second gateways G2 are connected to the network server NS, with two second gateways G2 being connected to the network server NS via a wired connection WN, and the other two second gateways G2 being connected to the network server NS via a wireless internet connection IP.The first gateways G1 and the second gateways G2 are interconnected via a meshed multi-hop network (MHF) such that a first gateway G1 does not require a direct connection to the network server NS. This extends the range of LoRaWAN networks by interposing a multi-hop network using the first gateway G1, thus achieving full compatibility with the LoRaWAN specification.

[0073] For early detection of a forest fire, an ED terminal first detects a forest fire by detecting a corresponding sensor signal from the sensor located in the ED terminal. In all of the examples shown here, the sensor in the ED terminal is a smoke detector. The ED terminal analyzes the sensor signal. If the analysis shows that the detected sensor signal indicates a forest fire, the ED terminal generates a corresponding alarm signal immediately after the analysis.

[0074] In a first transmission, the alarm signal is sent from the terminal device ED to a first gateway G1 via a single-hop connection (FSK) using the first communication interface K1. Upon receipt of the alarm signal at the first gateway G1, the first gateway G1 forwards the received alarm signal to a second gateway G2 via a multi-hop connection (MHF). The second gateway G2 also receives the alarm signal and forwards it to the network server NS via a wired connection (WN) or a wireless Internet connection (IP).

[0075] After the first alarm signal is sent, the terminal device ED waits for a configurable time interval for the receipt of a response signal on the terminal device ED. If the response signal is not received on the terminal device ED after the time interval has elapsed, a second alarm signal is sent from the terminal device ED via the second communication interface KS of the terminal device ED. In contrast to the first alarm signal, the second transmission is made via a satellite connection directly to the network server NS.

[0076] Optionally, the LoRaWAN mesh gateway network can comprise one mesh gateway (MGDn). The mesh gateway (MGDn) is a combination of the second gateway (G2) and the third gateway (G3). The mesh gateways (MGDn) communicate with each other via a 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).

[0077] A detailed view of an inventive forest fire early detection system 10 shows Fig. 2. The forest fire early detection system 10 has a plurality of terminal devices ED, with eight terminal devices ED each connected to a first gateway G1 via a single-hop connection FSK. The first gateways G1 are connected to each other and to second gateways G2. The second gateways G2 are connected to the network server NS via a wired connection WN or a wireless internet connection IP. One terminal device ED is connected to the network server NS directly via the satellite connection SAT.

[0078] A further detailed view of the forest fire early detection system 10 according to the invention shows Fig. 3, wherein ACK signals S-ACK are exchanged. The forest fire early detection system 10 has a plurality of terminal devices ED, each connected to a first gateway G1 via a single-hop connection FSK. Two terminal devices ED are each connected to two first gateways G1. For example, one terminal device ED is connected directly to the network server NS via a satellite connection SAT. In contrast to the previous embodiment (see Fig. 2) Here, an ACK signal is sent to the terminals ED from the first gateway G1 connected to the terminal ED after the first gateway G1 has received a message from the terminal ED. The ACK signal can be a signal for the terminal ED to close a download-receive time window and enter monitoring mode.

[0079] The first gateways G1 each have an ACK signal generation unit. The ACK signal (from the English "acknowledgement") is a signal used during data transmission to confirm receipt of a message from the terminal device ED. This ensures that a message has been sent correctly by the terminal device ED. Likewise, the terminal device ED does not need to be constantly active. This reduces power consumption, thus increasing the service life of the terminal device ED.

[0080] Fig. Figure 4 shows an embodiment of a terminal ED that can be used as an emergency communication terminal ED in the forest fire early detection system 10. In this embodiment, the terminal ED has two different communication interfaces K1, KS, which use different communication technologies. The first communication interface K1 is suitable for sending messages, in particular alarm signals, to gateways G1, G2 via a single-hop connection FSK and for receiving messages from gateways G1, G2. The second communication interface KS is suitable for forwarding signals directly to the network server NS via a satellite connection SAT and receiving them from the network server NS.

[0081] The terminal ED has a sensor for detecting a forest fire, in this embodiment a smoke detector. The controller has a microprocessor with memory, which executes a software program for selecting the communication interface K1, KS for sending an alarm signal to and receiving an acknowledgment of receipt MS from a gateway G1, G2 via the first communication interface K1, or for sending an alarm signal to and receiving an acknowledgment of receipt MS via a satellite connection SAT from the network server NS using the second communication interface KS.

[0082] The terminal device ED has a self-sufficient energy supply E, for example, using batteries, capacitors, or energy conversion via a solar cell and additional energy storage. The energy storage is dimensioned such that it can store an amount of energy greater than the energy required to communicate via the second communication interface KS. In particular, the energy storage can store an amount of energy more than twice the energy required to communicate via the second communication interface KS. In this and all subsequent embodiments, the energy storage can store an amount of energy three times greater than the energy required to communicate via the second communication interface KS.The signal received by the terminal device ED is forwarded to the network server NS via satellite communication SAT only if the signal received by the terminal device ED is an alarm signal or if the energy storage of the terminal device ED contains more energy than is required for two consecutive forwardings via satellite communication SAT. This ensures that sufficient energy is available in the terminal device ED to generate and forward an alarm signal. To test the satellite communication SAT, in addition to forwarding alarm signals, only test signals are sent via satellite communication SAT.

[0083] Fig. Figure 5 shows a sequence diagram of a standard LoRaWAN network 1 for implementing the inventive method according to the LoRaWAN protocol, wherein a terminal device ED is connected to a first gateway G1 via a single-hop connection FSK. The terminal device ED is used as an emergency communication terminal ED in the forest fire early detection system 10.

[0084] First, a forest fire is detected by the terminal device ED. On the terminal device ED, the controller generates a corresponding message ME (alarm signal) eg, which the terminal device ED sends e-s1 to a first gateway G1 via the first communication interface K1. The first gateway G1 receives the message ME and forwards it ME g1-f to the network server NS. In this exemplary embodiment, the forwarding g1-f from the first gateway G1 is unsuccessful. The message ME is therefore not received by the network server NS, and the network server NS does not generate an acknowledgment MS.

[0085] The message ME is therefore sent a second time by the terminal ED e-s2, the second time via the second communication interface KS of the terminal ED directly to the network server NS, which receives the message ME nr. Immediately after receiving the message ME, the network server NS generates a receipt acknowledgment MS, which is sent back to the first gateway G1 ns. The gateway G1 in turn forwards this receipt acknowledgment MS g1-f to the terminal ED, where the receipt acknowledgment MS is received er.

[0086] Fig. Figure 6 shows a sequence diagram of a LoRaWAN mesh gateway network 1, in which the end devices ED are connected via a single-hop connection FSK (see Fig. 1) are connected to first gateways G1. The terminal ED is also used as an emergency communication terminal ED in the forest fire early detection system 10. After the detection ed of a forest fire and the generation eg of a message ME, the software program controlling the terminal ED selects the communication interface K1, KS of the terminal ED, with which a first sending e-s1 of the message ME takes place. The first sending e-s1 of the message ME takes place via the first communication interface K1 to a first gateway G1. The first gateway G1 forwards g1-f the message ME via a multi-hop connection and usually a plurality of first gateways G1 to a second gateway G2.

[0087] The second gateway G2 receives the message ME and forwards this message ME g2-f to the network server NS, whereby in this embodiment the forwarding g2-f is unsuccessful, the message ME does not reach the network server NS and the network server NS does not generate an acknowledgment of receipt MS. The message ME is therefore sent a second time e-s2 by the terminal ED, the second time via the second communication interface KS of the terminal ED directly to the satellite S. The satellite S forwards sf the message ME to the network server NS, which receives the message ME nr. Immediately after receiving the message ME, the network server NS generates an acknowledgment of receipt MS, which is sent ns to the satellite S. The satellite S receives the acknowledgment of receipt MS and sf forwards the acknowledgment MS to the second gateway G2, which forwards the acknowledgment MS to the first gateway G1 g2-f.The second gateway G2 forwards this acknowledgement MS (g1-f) to the end device ED, where the acknowledgement MS is received. In the star architecture of a LoRaWAN network 1 (see . Fig. 1) this communication is very fast because each terminal device ED communicates with the network server NS via at least a second gateway G2.

[0088] In Fig. 7 shows a sequence diagram of a LoRaWAN mesh gateway network 1, in which, like in the previous embodiment (see Fig. 6) a message ME from the terminal ED is received via a first gateway G1 by the second gateway G2, via which the message ME is forwarded to the network server NS g2-f.

[0089] In this embodiment, this message ME is also not received by the terminal ED after the first sending e-s1 of the message ME, e.g. due to a connection error on the network server NS, the network server NS does not create and therefore does not send an acknowledgment MS to the terminal ED, which created the message ME and sent it by a first sending e-s1.

[0090] After a time interval t i Between the failed forwarding g2-f and the non-receipt of an acknowledgment MS on the terminal ED, ee selects the program for selecting the communication interface K1, KS, the satellite communication interface KS for sending the message ME from the terminal ED, via which the message ME is sent from the terminal ED to the satellite S e-s2 and forwarded from the satellite S to the network server NS sf. The time interval t i is chosen such that the time interval t ibetween receipt of the message ME and non-receipt of the receipt confirmation MS is greater by a factor of 2, preferably by a factor of 1.5, and particularly preferably by a factor of 1.25 than the duration between receipt of a previously received message ME and receipt of the receipt confirmation MS from the network server NS associated with this previously received signal on the terminal ED. In this embodiment, the time interval t i 1.25 times. LIST OF REFERENCE SYMBOLS 1 mesh gateway network 10 Forest fire early warning system ED, EDn end devices / sensors G1 First Gateway G2 Second Gateway NS Network Server IP Internet Protocol MHF multi-hop radio network FSK FSK modulation, single-hop connection WN Wired connection E Energy supply K1 First communication interface KS Second communication interface / satellite communication interface S communications satellite, SAT satellite connection W Forest ed Detecting a forest fire e.g. generating a message e-s1 First message sent from the terminal device e-s2 Second message sent from the terminal device the message reception from the terminal g1-f Message forwarding from the first gateway g1-e Message reception from the first gateway g2-f Message forwarding from the second gateway sf message forwarding from satellite nr Message reception on the network server ns Message sending from the network server ME message generated by the device MS acknowledgement of receipt t i Time interval QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2008 / 0309502 A1

[0005]

Claims

[1] Forest fire early detection system (10) with a mesh gateway network (1) with • a network server (NS), • a first gateway (G1) • multiple end devices (ED), characterized by that the terminal (ED) has a first communication interface (K1) to the first gateway (G1) and a second communication interface (KS) to an external device (S). [2] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 1, characterized by that the second communication interface (KS) is suitable for using a wireless communication technology. [3] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 1 or 2, characterized by that the first communication interface (K1) is different from the second communication interface (KS) of the terminal device (ED). [4] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 3, characterized by that the second communication interface (KS) is suitable for using a communication technology different from the communication technologies usable by the first communication interface (K1) and / or a communication protocol different from the communication protocols usable by the first communication interface (K1). [5] Forest fire early detection system (10) with a mesh gateway network (1) according to one or more of the preceding claims, characterized by that the second communication interface (KS) is suitable for communicating with a communication satellite (S). [6] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 5, characterized by that the first communication interface (K1) is unsuitable for communicating directly with a communication satellite (S). [7] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 5 or 6, characterized bythat the terminal (ED) is suitable for communicating via the communication satellite (S) with a gateway (G1, G2) of the forest fire early warning system (10) or the network server (NS). [8] Forest fire early detection system (10) with a mesh gateway network (1) according to one or more of the preceding claims, characterized by that the terminal device (ED) is intended for off-grid use and has an autonomous power supply (E). [9] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 8, characterized by that the self-sufficient power supply (E) has an energy conversion device (EK) and / or an energy storage device (ES). [10] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 8 or 9, characterized bythat the energy storage device (ES) can store more energy than is consumed by a standard communication to the first gateway (SG) and by a standard communication to the communication satellite (S). [11] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 10, characterized by that the energy storage device (ES) can store an amount of energy that is more than twice the energy required to communicate via the second communication interface (KS). [12] Forest fire early detection system (10) with a mesh gateway network (1) according to one or more of claims 8 to 11, characterized by that the energy conversion device (EK) comprises a solar cell, a wind turbine and / or is suitable for converting energy from the environment into electrical energy. [13] Forest fire early detection system (10) with a mesh gateway network (1) according to one or more of the preceding claims, characterized by that the first communication interface (K1) is suitable for sending and receiving LPWAN messages. [14] Forest fire early detection system (10) with a mesh gateway network (1) according to one or more of the preceding claims, characterized by that the shortest communication route from the terminal device (ED) via the first gateway (G1) to the network server (NS) via at least a second gateway (G2). [15] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 14, characterized by that the second gateway (G2) is different from the first gateway (G1). [16] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 15, characterized by that the second gateway (G2) has different communication interfaces than the first gateway (G1). [17] Forest fire early detection system (10) with a mesh gateway network (1) according to one or more of claims 14 to 16, characterized by that the second gateway (G2) is suitable for communicating directly with the network server (NS), whereby the first gateway (G1) is unsuitable for communicating directly with the network server (NS). [18] Forest fire early detection system (10) with a mesh gateway network (1) according to one or more of the preceding claims, characterized by that the first and / or second gateway (G1, G2) is unsuitable for communication with a communications satellite (S). [19] Forest fire early detection system (10) with a mesh gateway network (1) according to one or more of the preceding claims, characterized bythat the network server (NS) has a first communication interface, wherein the first communication interface is suitable for communicating with the second gateway (G1), and the network server (NS) has a second communication interface which is suitable for communicating with the terminal (ED), wherein the second communication interface is unsuitable for communicating with the first gateway (G1). [20] Forest fire early detection system (10) with a mesh gateway network (1) according to claim 19, characterized by that the second communication interface is suitable for satellite communication (SAT). [21] Method for the early detection of a forest fire with a forest fire early detection system (10) comprising the steps • Detection (ed) of a forest fire by an end device (ED) of the forest fire detection system (10) • Generation (eg) of a signal (ME) in the terminal (ED) • First transmission (e-s1) of the signal (ME) from the terminal (ED) via a first communication interface (K1) of the terminal (ED), • Waiting for the reception (er) of a response signal (MS) on the terminal (ED), • Second transmission (e-s2) of the signal (ME) from the terminal device (ED) via a second communication interface (KS) of the terminal device (ED). [22] Method for the early detection of a forest fire with a forest fire early detection system (10) according to claim 21, characterized by that the signal (ME) is sent (e-s1) via a first communication interface (K1) of the terminal device (ED) to a first gateway (G1) of the forest fire early detection system (10). [23] Method for the early detection of a forest fire with a forest fire early detection system (10) according to claim 21 or 22, characterized bythat the first transmission (e-s1) of the signal (ME) via the first communication interface of the terminal (ED) to a network server (NS) of the forest fire early detection system (10). [24] Method for the early detection of a forest fire with a forest fire early detection system (10) according to one or more of claims 21 to 23, characterized by that the signal (ME) contains information about the detected forest fire. [25] Method for the early detection of a forest fire with a forest fire early detection system (10) according to one or more of claims 21 to 24, characterized by that waiting for the reception (er) of a response signal (MS) on the terminal (ED) over a specified time interval (t i ) takes place. [26] Method for the early detection of a forest fire with a forest fire early detection system (10) according to claim 25, characterized by that the time interval (t i) is longer than the average duration between the first transmission (e-s1) of the signal (ME) and reception (er) of the response signal (MS). [27] Method for the early detection of a forest fire with a forest fire early detection system (10) according to claim 26, characterized by that the time interval (t i ) between reception (er) of the signal (ME) and non-reception of the response signal (MS) is greater by a factor of 2, preferably by a factor of 1.5 and particularly preferably by a factor of 1.25 than the duration between reception of an earlier received signal and reception of the response signal of the network server (NS) associated with this earlier received signal. [28] Method for the early detection of a forest fire with a forest fire early detection system (10) according to one or more of claims 21 to 27, characterized bythat the second transmission (e-s2) takes place via the second communication interface (KS) of the terminal (ED), which is suitable for communicating with a communication satellite (S). [29] Method for the early detection of a forest fire with a forest fire early detection system (10) according to claim 28, characterized by that the second transmission (e-s2) of the signal (ME) takes place via the second communication interface (K2) of the terminal (ED) to a network server (NS) of the forest fire early detection system (10). [30] Method for the early detection of a forest fire with a forest fire early detection system (10) according to one or more of claims 21 to 29, characterized by that the response signal (MS) is an acknowledgment of receipt (MS) from the network server (NS). [31] Method for the early detection of a forest fire with a forest fire early detection system (10) according to one or more of claims 21 to 30, characterized bythat the second transmission (e-s2) of the signal (ME) via the second communication interface (KS) of the terminal (ED) only takes place if the signal (ME) is an alarm signal or the energy storage (ES) of the terminal (ED) has more energy than is necessary for two consecutive transmissions (e-s2) by means of satellite communication (SAT). [32] Method for the early detection of a forest fire with a forest fire early detection system (10) according to one or more of claims 21 to 31, characterized by that the second transmission (e-s2) of the signal (ME) only takes place via the second communication interface (KS) of the terminal device (ED) if the signal (ME) was previously sent (e-s1) by the terminal device (ED) via the first communication interface (K1). [33] Method for the early detection of a forest fire with a forest fire early detection system (10) according to one or more of claims 21 to 32, characterized bythat the second transmission (e-s2) of the signal (ME) only takes place via the second communication interface (KS) of the terminal device (ED) to the network server (NS) if no confirmation of receipt (MS) of the transmitted signal (ME) has previously been received from the network server (NS) on the terminal device (ED). [34] Method for the early detection of a forest fire with a forest fire early detection system (10) according to claim 33, characterized by that the second transmission (e-s2) of the signal (ME) only takes place via the second communication interface (KS) to the network server (NS) if no confirmation of receipt (MS) of the transmitted signal (ME) has previously been received from the network server (NS) via a communication interface (K1) different from the second communication interface (KS) on the terminal device (ED). [35] Method for the early detection of a forest fire with a forest fire early detection system (10) according to one or more of claims 21 to 34, characterized bythat after the detection (ed) of a forest fire, a software program for selecting the communication interface (K1, KS) is started (ee). [36] Method for the early detection of a forest fire with a forest fire early detection system (10) according to claim 35, characterized by that the starting (ee) of the software program for selecting the communication interface (K1, KS) takes place immediately after the analysis of the signal on the terminal device (ED). [37] Emergency communication terminal (ED) for a forest fire early warning system (10) comprising: • a sensor, whereby the sensor is suitable for detecting a forest fire, • an energy supply device (E), • a first communication interface (K1), • a second communication interface (KS), wherein the first communication interface (K1) is different from the second communication interface (KS). [38] Emergency communication terminal (ED) for a forest fire early detection system (10) according to claim 37, characterized by that the first communication interface (K1) is suitable for communicating with a gateway (G1, G2) of the forest fire early detection system (10). [39] Emergency communication terminal (ED) for a forest fire early detection system (10) according to claim 37 or 38, characterized by that the second communication interface (KS) is suitable for communicating with a communication device outside the forest fire early detection system (10). [40] Emergency communication terminal (ED) for a forest fire early detection system (10) according to claim 39, characterized by that the second communication interface (KS) is suitable for communicating with a communication satellite (S). [41] Emergency communication terminal (ED) for a forest fire early detection system (10) according to one or more of claims 37 to 40, characterized bythat the emergency communication terminal (ED) has a controller which is suitable for executing a software program which selects the communication interface (K1, KS) to be used for communication. [42] Emergency communication terminal (ED) for a forest fire early detection system (10) according to one or more of claims 37 to 41, characterized by that the controller is suitable for controlling the communication interfaces (K1, KS) separately. [43] Emergency communication terminal (ED) for a forest fire early detection system (10) according to one or more of claims 37 to 42, characterized by that the energy supply device (E) has an energy store which is suitable for storing more energy, preferably more than 1.5 times as much energy and particularly preferably more than 2 times as much energy as is necessary for communication via the second communication interface (KS).

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