Device and method for increasing LoRa signal transmission distance

Abstract

The invention mainly relates to the technical field of wireless transmission, and provides equipment and a method for increasing a LoRa signal transmission distance in order to solve the problems of limited transmission distance and limited communication of the current LoRa technology. A main control board, a switching module, a LoRa signal receiving interface set module, a LoRa signal transmitting interface set module, a first relay, a second relay, a LoRa signal receiving circuit and a LoRa signal transmitting circuit are arranged in the equipment shell. The exchange module, the LoRa signal receiving interface set module and the LoRa signal transmitting interface set module are connected with the main control board, the LoRa signal receiving interface set module is connected with an external LoRa signal receiving module through a first relay and a LoRa signal receiving circuit, and the LoRa signal transmitting interface set module is connected with an external LoRa signal transmitting module through a second relay and a LoRa signal transmitting circuit.

Description

Technical Field

[0001] The present invention mainly relates to the field of wireless transmission technology, and in particular to a device and method for improving the transmission distance of a LoRa signal. Background Art

[0002] LoRa is a low-power LAN wireless standard developed by Semtech. Its name "LoRa" stands for Long Range Radio. Its biggest feature is that it can transmit farther than other wireless methods under the same power consumption conditions, achieving the unity of low power consumption and long distance. It is 3-5 times longer than traditional wireless radio frequency communication distance under the same power consumption. There are existing application products based on LoRa technology. The current application scenarios are mainly concentrated in the fields of smart agriculture, smart cities, alarm systems, environmental monitoring, industrial automation, etc. Its main function is to transmit the corresponding data back. The specific deployment architecture is to deploy collection equipment at the remote end to collect data information such as temperature, humidity, light, and location around it, and transmit it to the management platform through LoRa technology for centralized analysis and processing to achieve real-time monitoring. At present, the application of LoRa technology can only perform simple one-way data transmission through the uplink channel, and does not have a relay function, and cannot build a metropolitan-level self-organizing network. Summary of the invention

[0003] Technical Problems to be Solved by the Invention

[0004] Provided is a device and method for improving the transmission distance of LoRa signals, aiming to solve the problems of limited transmission distance and restricted communication of the current LoRa technology.

[0005] The technical solution adopted by the present invention to solve the above technical problems

[0006] A device for improving the transmission distance of a LoRa signal, comprising a main control board, a switching module, a LoRa signal receiving interface module, a LoRa signal sending interface module, a first relay and a second relay, a LoRa signal receiving circuit and a LoRa signal sending circuit;

[0007] The switching module, the LoRa signal receiving interface set module and the LoRa signal sending interface set module are connected to the main control board. The LoRa signal receiving interface set module is connected to the LoRa signal receiving module of the peripheral device through the first relay and the LoRa signal receiving circuit. The LoRa signal sending interface set module is connected to the LoRa signal sending module of the peripheral device through the second relay and the LoRa signal sending circuit.

[0008] Furthermore, it also includes a third relay and a 4G interface set module, wherein the 4G interface set module is connected to the main control board and is connected to the 4G module through the third relay.

[0009] Furthermore, it also includes a fourth relay, a fifth relay, a sixth relay, a speaker drive circuit, an audible and visual alarm drive circuit, and a pickup receiving circuit; the speaker is connected to the main control board via the speaker drive circuit and the fourth relay in sequence, the audible and visual alarm is connected to the main control board via the audible and visual alarm drive circuit and the fifth relay in sequence, and the pickup is connected to the main control board via the pickup receiving circuit and the sixth relay in sequence.

[0010] Furthermore, it also includes a power supply management circuit and an external power supply, and the external power supply supplies power to the device through the power supply management circuit.

[0011] Furthermore, copper pillars are provided on the main control board and the LoRa signal sending interface assembly module, the switching module is arranged above the main control board and isolated from the main control board by the copper pillars, and the LoRa signal receiving interface assembly module is arranged above the LoRa signal sending interface assembly module and isolated by the copper pillars.

[0012] Based on the above-mentioned device for improving the transmission distance of LoRa signals, the present invention also provides a method for improving the transmission distance of LoRa signals, which specifically includes the following steps:

[0013] Arrange multiple devices for improving the transmission distance of LoRa signals as relay devices, and clarify the signal pre-sequence and subsequent relationship between the multiple relay devices;

[0014] After receiving the message, the preceding relay device checks the message source and consistency, and selects the subsequent transmission target relay device according to the message direction;

[0015] The relay devices that send and receive data first handshake each other, and then forward the message after the handshake is successful.

[0016] Furthermore, the method also includes: when the relay device is transmitting data, if no response is received after a timeout, retransmitting within the handshake cycle until a response is received or the maximum number of retransmissions is reached.

[0017] Beneficial effects of the present invention

[0018] (1) Based on the device and method for improving the transmission distance of LoRa signals described in the present invention, multiple relay communications can be performed, which can be applicable to areas without public networks, complex terrain, and sparsely populated areas, and has broad application prospects; and the receiving sensitivity is high and the power consumption is low. When the line of sight is not blocked, the communication distance can reach more than 14 kilometers; when the line of sight is blocked, through the transmission of the signal, its communication distance can also reach 10 kilometers. The device supports parallel processing of multiple channels and multiple data rates, has a large system capacity, and can monitor the link status, communication device status, charging device status, battery status, and power amplifier status of remote devices.

[0019] (2) The present invention uses the low-power wide area local area network of LoRa technology as the main network and the 4G mobile public network as the backup link. The main and backup links can be switched manually / automatically, fully ensuring the stability and emergency response of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a system frame diagram of a device for improving the transmission distance of LoRa signals according to the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of a device for improving the transmission distance of LoRa signals according to the present invention;

[0022] Figure 3 This is a schematic diagram of a device panel for improving the transmission distance of LoRa signals according to the present invention;

[0023] Figure 4 A flow chart of a method for improving the transmission distance of LoRa signals according to the present invention;

[0024] Figure 5 A retransmission flow chart of a method for improving the transmission distance of LoRa signals according to the present invention;

[0025] A-switching module, B-main control board, C-LoRa signal receiving interface module, D-LoRa signal sending interface module, E-device housing. DETAILED DESCRIPTION

[0026] The device for improving the transmission distance of LoRa signals described in the present invention mainly includes a device housing E, and the device housing E includes a main control board B, a switching module A, a LoRa signal receiving interface set module C, a LoRa signal sending interface set module D and a 4G interface set module F.

[0027] Switching module A is the information exchange center, which aggregates various information and forwards it to other modules. Figure 2 As shown, the switching module A specifically includes a converged USB interface 1, a power input interface 2, a pickup signal input USB interface 3, a system configuration data input USB interface 4, a 485 / 232 serial port USB interface 5, and a system program input USB interface 6.

[0028] The main control board B serves as the control and data processing center of the device and includes a power switch interface 7, a power output interface 8, a kernel module power switch 9, and a power input interface 10; a speaker output interface 25, a speaker input interface 26, an audible and visual alarm input interface 27, and an audible and visual alarm output interface 28; a main control board B to RJ45 network port USB interface 31, a main control board B to 4G interface module F USB interface 32, a main control board B to switching module A USB interface 33, and a main control board B to WiFi antenna USB interface 40; a LoRa signal receiving interface module C data interface and a LoRa signal sending interface module D data interface 30.

[0029] like Figure 3 As shown, the panel E of the device housing includes a device power switch 11, a device power input interface 12, a microphone input port 13, an RJ45 network port 14, a LoRa signal sending interface module DRF antenna interface 15, a speaker output port 16, a LoRa signal receiving interface module CRF antenna interface 17, a speaker input port 18, a WiFi antenna interface 19, a 4G card access interface 20, a 4G antenna interface 21, a 485 / 232 serial port 22, a system main program USB interface 23, and a system configuration data USB interface 24.

[0030] The LoRa signal receiving interface module C includes a data interface 34 and an RF antenna interface 37. The LoRa signal sending interface module D includes a data interface 35 and an RF antenna interface 37. The 4G interface module F includes an antenna interface 38 and a 4G module card interface 39.

[0031] like Figure 1 As shown, the main control board B is set in the upper left corner of the device housing E, and the switching module A is set above the main control board B and isolated from the main control board B by a copper column; the LoRa signal receiving interface module C and the LoRa signal sending interface module D are set in the upper right corner of the device housing E, and the LoRa signal receiving interface module C is isolated above the LoRa signal sending interface module D by a copper column; the 4G interface module F is set in the lower right corner of the device housing E. The whole machine is installed in a rack and cabinet type, supports 10V-16VDC voltage, has a power consumption of no more than 10W, and is set to an IP66 protection level.

[0032] The converged USB interface 1 in the switching module A is connected to the USB interface 33 on the main control board B through a USB data cable; the pickup signal input USB interface 3 is connected to the pickup input port 13 on the device housing E, and the pickup input interface 13 on the device housing E is connected to the pickup receiving circuit and the pickup through a third electromagnetic relay (the relays used in the invention are all electromagnetic relays) to realize the sound pickup function; the system configuration data input USB interface 4 is connected to the system configuration data USB interface 24 on the device housing E, which can modify the configuration of the device; the 485 / 232 serial port USB interface 5 is connected to the 485 / 232 serial port 22 on the device housing E through a data cable to provide serial port communication to the outside; the system program input USB interface 6 is connected to the system main program USB interface 23 on the device housing E through a USB data cable to modify the main program of the device.

[0033] The power switch interface 7 of the main control board B and the power switch 9 of the core module of the main control board B are connected to the device power switch 11 on the device housing E through the power line, so as to realize the switching of the power of the main control board B; the power output interface 8 of the main control board B is connected to the power input interface 2 of the switching module A through the power line to supply power to the switching module A. The power input interface 10 on the main control board B is connected to the device power input interface 12 on the device housing E through the power line to realize the power supply function of the whole set of equipment, and the power input interface 12 on the device housing E is connected to the external power supply through the power supply management circuit.

[0034] The speaker output interface 25 and the sound and light alarm output interface 28 on the main control board B are connected to the speaker output port 16 of the device housing E through a signal line. Figure 1 As shown, the speaker output interface 16 of the device housing E is connected to the speaker through the first electromagnetic relay and the speaker driving circuit to realize the audio output function of the system. The speaker output interface 16 of the device housing E is also connected to the sound and light alarm driving circuit and the sound and light alarm through the second electromagnetic relay to perform sound and light alarm; the speaker input interface 26 on the main control board B and the sound and light alarm input interface 27 are connected to the speaker input port 18 on the device housing E through a signal line to realize the playback of external audio.

[0035] The main control board B to RJ45 network port USB interface 31 is connected to the RJ45 network port 14 on the device shell E through a USB data cable to realize communication with external devices; the main control board B to 4G interface set module F USB interface 32 is connected to the 4G interface set module F through a USB data cable to realize communication with the 4G module; the main control board B to the switching module A USB interface 33 is connected to the switching module A aggregation USB interface 1 through a USB data cable to realize communication with the switching module A; the main control board B to the WiFi antenna USB interface 40 is connected to the device shell E WiFi antenna interface 19 through a USB data cable to realize the sending and receiving of WiFi signals.

[0036] The data interface 29 of the LoRa signal receiving interface module C on the main control board B is connected to the data interface 34 of the LoRa signal receiving interface module C through a flat cable, and the data interface 34 of the LoRa signal receiving interface module C is connected to the LoRa signal receiving interface module C through the sixth electromagnetic relay and the LoRa signal receiving circuit; the RF antenna interface 36 of the LoRa signal receiving interface module C is connected to the LoRa signal receiving interface module CRF antenna interface 17 on the device housing E through a radio frequency line, thereby realizing the system LoRa signal receiving function.

[0037] The LoRa signal sending interface set module D provides information sending function for the entire system. The data interface 35 of the LoRa signal sending interface set module D is connected to the data interface 30 of the LoRa signal sending interface set module D on the main control board B through a data cable to realize communication with the main control board B; the RF antenna interface 37 of the LoRa signal sending interface set module D is connected to the RF antenna interface 15 of the device's housingless LoRa signal sending interface set module DD through a radio frequency line; the fourth electromagnetic relay and the LoRa signal sending circuit and the LoRa signal sending circuit are connected to the LoRa transmitting module, and the system LoRa signal sending function is realized through the LoRa transmitting antenna.

[0038] The antenna interface 38 of the 4G interface assembly module F is connected to the 4G antenna interface 21 of the device housing E through a radio frequency line to realize the sending and receiving of 4G signals; the card interface 39 of the 4G interface assembly module F is connected to the 4G card access interface 20 of the device housing E through a flat cable, and the fifth electromagnetic relay is connected to the 4G transceiver module through the 4G signal transceiver circuit, and the access function of the 4G card is realized through the 4G antenna.

[0039] Based on the above-mentioned device for improving the transmission distance of LoRa signals, the method for improving the transmission distance of LoRa signals described in the present invention specifically includes: setting a plurality of the above-mentioned devices for improving the transmission distance of LoRa signals as relays to establish a transmission link, and clarifying the predecessor and successor relationships of each device. The audio, text, control and other information that the management platform needs to transmit is modulated onto the baseband signal and amplified. When the data message arrives from the preceding relay device, the subsequent relay device replaces the message header and forwards the message. Figure 4 As shown, the specific steps are as follows:

[0040] 1. After receiving the message, the relay device checks the message source and consistency;

[0041] 2. Select the target device for subsequent transmission according to the message direction;

[0042] 3. Before the relay devices communicate, they must first handshake, and then forward the message after the handshake succeeds. When the relay device sends data, it must ensure that the frequency is consistent with the destination radio frequency. When the device receives data, it must ensure that the frequency is consistent with the sending device. The specific rules are as follows:

[0043] 1) Each relay device is configured with a working frequency point, and when the device is in receiving mode, it works at this frequency point;

[0044] 2) Each relay device obtains the working frequency of the previous hop relay device and the next hop relay device. When there is data to be sent to the next hop relay device, it switches to the other party's working frequency to send data;

[0045] 3) Since the last-hop relay only needs to interact with the previous-hop relay via LoRa and communicate internally with the base station module, there will be no interference problem. Therefore, the operating frequency of the last-hop relay can be consistent with that of the previous hop.

[0046] Data needs to pass through multiple relay devices to reach the server. If data is lost in a relay device in the link, the message will eventually be lost. To ensure transmission reliability, the transmission of data messages needs to adopt a retransmission confirmation mechanism to ensure reliable delivery of messages. Figure 5 As shown, the specific data retransmission mechanism is as follows:

[0047] Relay device n sends a standard LoRaWAN protocol message. The relay detection RFU field is 0 to identify it as a LoRaWAN message. Relay device n-1 needs to respond with a normal LoRaWANACK message to relay device n. Due to reliability requirements, relay device n-1 needs to temporarily store data in the cache, and delete the cached data after receiving the response. If it is not received within the timeout, it will continue to transmit in this handshake cycle until a response is received or the maximum number of retransmissions is reached.

[0048] After relay device n-1 receives the data message from relay device n, it needs to convert it into an internal protocol message and forward it to the front-end relay device. Due to reliability requirements, this process also needs to introduce a confirmation retransmission mechanism. Similarly, the frequency used for forwarding should be consistent with the frequency used for receiving the message. Finally, after relay device 1 receives the message forwarded by relay device 2, it needs to forward it to the central control station. The central control station converts the message data format and transfers the data to the server to complete the data transmission.

Claims

1. A device for improving the transmission distance of LoRa signals, characterized in that: It includes a main control board, a switching module, a LoRa signal receiving interface module, a LoRa signal sending interface module, a first relay and a second relay, a LoRa signal receiving circuit and a LoRa signal sending circuit; The switching module, the LoRa signal receiving interface set module and the LoRa signal sending interface set module are connected to the main control board. The LoRa signal receiving interface set module is connected to the LoRa signal receiving module of the peripheral device through the first relay and the LoRa signal receiving circuit. The LoRa signal sending interface set module is connected to the LoRa signal sending module of the peripheral device through the second relay and the LoRa signal sending circuit.

2. A device for improving the transmission distance of LoRa signals according to claim 1, characterized in that: It also includes a third relay and a 4G interface set module. The 4G interface set module is connected to the main control board and is connected to the 4G module of the peripheral device through the third relay.

3. A device for improving the transmission distance of LoRa signals according to claim 2, characterized in that: It also includes a fourth relay, a fifth relay, a sixth relay, a loudspeaker drive circuit, an audible and visual alarm drive circuit, and a pickup receiving circuit; the loudspeaker is sequentially connected to the main control board via the loudspeaker drive circuit and the fourth relay, the audible and visual alarm is sequentially connected to the main control board via the audible and visual alarm drive circuit and the fifth relay, and the pickup is sequentially connected to the main control board via the pickup receiving circuit and the sixth relay.

4. A device for improving the transmission distance of LoRa signals according to any one of claims 1 to 3, characterized in that: It also includes a power supply management circuit and an external power supply, and the external power supply supplies power to the device through the power supply management circuit.

5. A device for improving the transmission distance of LoRa signals according to any one of claims 1 to 3, characterized in that: Copper pillars are arranged on the main control board and the LoRa signal sending interface module, the switching module is arranged above the main control board and isolated from the main control board by the copper pillars, and the LoRa signal receiving interface module is arranged above the LoRa signal sending interface module and isolated by the copper pillars.

6. A method for improving the transmission distance of LoRa signals, using a device for improving the transmission distance of LoRa signals according to any one of claims 1 to 5, characterized in that: The following steps are involved: Arrange multiple devices for improving the transmission distance of LoRa signals as relay devices, and clarify the signal pre-sequence and subsequent relationship between the multiple relay devices; After receiving the message, the preceding relay device checks the message source and consistency, and selects the subsequent transmission target relay device according to the message direction; The relay devices that send and receive data first handshake each other, and then forward the message after the handshake is successful.

7. A method for improving the transmission distance of LoRa signals according to claim 6, characterized in that: The method further comprises: when the relay device is transmitting data, if no response is received after a timeout, retransmitting within a handshake cycle until a response is received or a maximum number of retransmissions is reached.

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