Wireless communication system based on LoRa

Abstract

The invention discloses a wireless communication system based on LoRa. The wireless communication system comprises TCP equipment, BCP equipment, a LoRa gateway and a server, the LoRa gateway chip is used for providing communication capability between the TCP equipment and the server and between the BCP equipment and the server; the server is used for realizing communication with the LoRa gateway; the TCP equipment is used for realizing reliable bidirectional data interaction with the LoRa gateway through the LoRa; and the BCP equipment is used for realizing unreliable bidirectional data interaction with the LoRa gateway through the LoRa. On the basis of keeping the advantages of long distance, low power consumption and safe intranet of the LoRa technology, through reasonable design and optimization of the protocol stack, the reliability of data transmission is improved, and the cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of positioning technology, and more specifically, to a LoRa-based wireless communication system. Background Technology

[0002] In IoT scenarios such as industrial safety, production management, and emergency rescue, accurate data transmission has become a crucial requirement for IoT applications. Global Navigation Satellite Systems (GNSS) provide global positioning capabilities, suitable for large-scale outdoor operating environments. Typically, location information needs to be uploaded to a management platform. Common backhaul methods include 4G cellular networks, Wi-Fi, and dedicated 2.4GHz wireless links. However, these backhaul methods have the following shortcomings in practical applications: (1) Due to the propagation characteristics, Wi-Fi and 2.4GHz dedicated wireless chains usually have a coverage radius of less than 100 meters, requiring the deployment of a large number of gateways, which increases construction and maintenance costs. Meanwhile, 4G networks often have blind spots in enclosed environments such as underground mines and factories, and cannot guarantee full coverage. (2) 4G networks consume a lot of power, and the positioning tags need to be charged or have their batteries replaced frequently, which is not conducive to long-term use; Wi-Fi and some 2.4GHz dedicated wireless chains also consume a lot of power when transmitting high-frequency data. (3) Large-scale gateway deployment and traffic tariffs will lead to a continuous increase in subsequent usage costs, especially in special environments such as mining areas and chemical plants, where equipment maintenance is difficult and further increases the total cost; (4) When using 4G network or Wi-Fi for data backhaul, the location information needs to be transmitted through the operator or third-party network, which poses a risk of being stolen or leaked. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a LoRa-based wireless communication system as a data backhaul channel. While retaining the advantages of LoRa technology such as long range, low power consumption, and secure intranet, it improves the reliability of data transmission and reduces costs through reasonable design and optimization of the protocol stack.

[0004] To achieve the above technical objectives, the present invention adopts the following technical solution: a LoRa-based wireless communication system, comprising: a TCP device, a BCP device, a LoRa gateway, and a server; The LoRa gateway is used to provide communication capabilities between TCP devices and servers, as well as between BCP devices and servers. The server is used to enable communication with the LoRa gateway; The TCP device is used to achieve reliable bidirectional data interaction with the LoRa gateway via LoRa; The BCP device is used to enable unreliable bidirectional data interaction with the LoRa gateway via LoRa.

[0005] Furthermore, the LoRa gateway includes: a gateway chip, a first LoRa terminal chip, and a second LoRa terminal chip; The first LoRa terminal chip is used to periodically broadcast sync packets, receive registration requests from TCP devices or BCP devices, and reply to registration responses from TCP devices or BCP devices. The gateway chip is used to receive data packets sent by TCP devices; The second LoRa terminal chip is used to send data response packets to the corresponding TCP device.

[0006] Furthermore, spectrum resources are allocated to the LoRa gateway, including: 3 common channels, 8 uplink channels, and 1 downlink channel, wherein: The spectrum resources allocated to the three common channels are 470MHz, 470.3MHz, and 470.6MHz, respectively. Spectrum resources allocated to 8 uplink channels , Indicates the number of LoRa gateways. ; Indicates the index of the uplink channel. ; Spectrum resources allocated for one downlink channel .

[0007] Furthermore, time-slice resource allocation is performed on the LoRa gateway: The first LoRa terminal chip is divided into 40 time slices, each 25ms in size. One time slice is used to broadcast a sync packet at 470MHz for time synchronization. The other time slices are used to receive registration requests from TCP or BCP devices at 470.3MHz and to reply to the registration responses from TCP or BCP devices at 470.6MHz. The second LoRa terminal chip is divided into 20 time slices, each 50ms in size. The gateway chip is divided into 20 time slices, each 50ms in size.

[0008] Furthermore, CRC checks are required on the sent data packets and data response packets: When the sender sends a data packet or data response packet, it calculates a CRC check value based on the packet header and payload, and fills the CRC check value into the end of the corresponding data packet or data response packet. After receiving the packet, the receiver recalculates the CRC check value based on the packet header and payload. If the recalculated CRC check value is the same as the CRC check value filled into the end, it means that the data is the same; otherwise, it is discarded.

[0009] Furthermore, the LoRa gateway also includes: an MCU, a GNSS module, and an interface module for connecting to the server; The GNSS module is used to provide PPS signals to achieve time synchronization of the LoRa gateway; The interface module for connecting to the server is used to enable data transmission between the LoRa gateway and the server; The MCU is used to drive the GNSS module, the interface module for connecting to the server, the gateway chip, the first LoRa terminal chip, and the second LoRa terminal chip to complete their respective functions.

[0010] Furthermore, both the TCP device and the BCP device include: an MCU, a third LoRa terminal chip, and a radio frequency front-end module; The MCU is used to drive the third LoRa terminal chip to communicate with the second LoRa terminal chip in the LoRa gateway. The radio frequency front-end module is connected to the third LoRa terminal chip and is used to enhance the LoRa radio frequency signal in the third LoRa terminal chip.

[0011] Furthermore, it also includes: GNSS satellites and switches; The GNSS satellite is used to achieve global positioning of the LoRa gateway; The switch is used to enable communication between the LoRa gateway and the server, as well as to enable communication with the public network.

[0012] Furthermore: For outdoor scenarios, time synchronization with GNSS satellites is achieved through the GNSS module in the LoRa gateway; For indoor scenarios, the server designates one LoRa gateway as the root node for time synchronization. Other LoRa gateways are synchronized with the address of the parent LoRa gateway specified by the server. During the broadcast of the first LoRa terminal chip of the parent LoRa gateway, the LoRa gateway switches to 470MHz to receive the broadcast sync packet of the parent LoRa gateway for time synchronization.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) The LoRa-based wireless communication system of the present invention supports the access of TCP devices and BCP devices. TCP devices can achieve reliable bidirectional data interaction with LoRa gateway through LoRa, which is suitable for scenarios with high requirements for data accuracy. BCP devices can perform unreliable bidirectional data interaction, which is suitable for scenarios with high requirements for real-time performance but not sensitive to the loss of a small amount of data. This diverse device support enables the wireless communication system to meet the needs of different types of applications. (2) In this invention, the LoRa gateway acts as an intermediate hub, providing communication capabilities between TCP devices, BCP devices and servers. The server focuses on communicating with the LoRa gateway. This layered design makes the communication architecture clearer and improves the overall efficiency and maintainability of the wireless communication system. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the architecture of the LoRa-based wireless communication system of the present invention; Figure 2 This is a schematic diagram of the internal modules of the LoRa gateway in this invention; Figure 3 This is a schematic diagram of the internal modules of the TCP device or BCP device in this invention; Figure 4 This is a schematic diagram illustrating the workflow of the LoRa-based wireless communication system of this invention. Detailed Implementation

[0015] The technical solution of the present invention will be further explained and described below with reference to the accompanying drawings.

[0016] like Figure 1This is a schematic diagram of the architecture of the LoRa-based wireless communication system of the present invention. The wireless communication system includes: a TCP device, a BCP device, a LoRa gateway, a server, a GNSS satellite, a switch, and an operator. The LoRa gateway provides communication capabilities between the TCP device and the server, and between the BCP device and the server. The server enables communication with the LoRa gateway. The TCP device enables reliable bidirectional data interaction with the LoRa gateway via LoRa. The BCP device enables unreliable bidirectional data interaction with the LoRa gateway via LoRa. The GNSS satellite enables global positioning of the LoRa gateway. The switch enables communication between the LoRa gateway and the server, and communication with the public network. The operator provides network services to devices using 4G / 5G modules that transmit data back through the public network. In this invention, the TCP device enables reliable bidirectional data interaction with the LoRa gateway via LoRa, suitable for scenarios with high data accuracy requirements. The BCP device allows for unreliable bidirectional data interaction, suitable for scenarios with high real-time requirements but insensitive to minor data loss. This diverse device support allows the wireless communication system to meet the needs of different types of applications. The LoRa gateway acts as an intermediary, providing communication capabilities between the TCP device, BCP device, and server. The server focuses on communicating with the LoRa gateway. This layered design makes the communication architecture clearer and improves the overall efficiency and maintainability of the wireless communication system. The long-range communication characteristics of LoRa technology enable the wireless communication system to connect devices and gateways over a wide area. Combined with the 4G / 5G network coverage of operators, the system's coverage is further expanded, enabling device access and data transmission in both urban and remote areas. Furthermore, the TCP device, BCP device, and LoRa gateway in the wireless communication system are independent functional modules. This modular design makes the wireless system easy to expand. When new devices or functions need to be added, only the corresponding modules need to be added and simply configured, without requiring large-scale modifications to the entire system, reducing the expansion cost and difficulty.

[0017] like Figure 2The LoRa gateway in this invention includes: a gateway chip, a first LoRa terminal chip, a second LoRa terminal chip, an MCU, a GNSS module, and an interface module for connecting to a server. The gateway chip used in this invention is any one of SX1301, SX1302, SX1308, and SX1303, possessing 8-channel receiving capability and strong parallel processing capability. The first and second LoRa terminal chips used in this invention are any one of SX1272, SX1276, SX1278, SX1262, and SX1268, featuring low power consumption and long-distance communication. The first LoRa terminal chip avoids conflicts between sync signals and registration / registration responses by operating at different frequencies; the second LoRa terminal chip provides downlink data at all times, and the gateway chip provides uplink data at all times, allowing them to operate "simultaneously" at different "frequency" levels, thereby achieving a full-duplex communication network and providing maximized data interaction capabilities.

[0018] The first LoRa terminal chip is used to periodically broadcast sync packets, receive registration requests from TCP devices or BCP devices, and reply to registration responses from TCP devices or BCP devices. It requires a total of 3 common channels. The gateway chip is used to receive data packets sent by TCP devices and requires 8 uplink channels; The second LoRa terminal chip is used to send data response packets to the corresponding TCP device, which requires a downlink channel; The GNSS module is used to provide PPS signals to achieve time synchronization for the LoRa gateway; The interface module for connecting to the server is used to enable data transmission between the LoRa gateway and the server; The MCU drives the GNSS module, the interface module connecting to the server, the gateway chip, the first LoRa terminal chip, and the second LoRa terminal chip to perform corresponding functions. Specifically, the MCU receives the PPS signal from the GNSS module through GPIO and communicates with the GNSS module through UART to achieve time synchronization. The interface module connecting to the server includes a CAT1 interface module and an Ethernet interface module. The CAT1 interface module communicates with the MCU through UART, and the Ethernet interface module communicates with the MCU through Ethernet. The MCU communicates with the second LoRa terminal chip and the first LoRa terminal chip through SPI. The MCU communicates with the gateway chip through SIP, and the gateway chip is connected to the external antenna through an RF feed line.

[0019] In one technical solution of this invention, spectrum resources of 470MHz~510MHz are allocated for LoRa use. Spectrum resource allocation for the LoRa gateway includes: 3 common channels, 8 uplink channels, and 1 downlink channel. Each channel is different to avoid mutual interference. The spectrum resources allocated to the three common channels are 470MHz, 470.3MHz, and 470.6MHz, respectively. Spectrum resources allocated to 8 uplink channels , Indicates the number of LoRa gateways. ; Indicates the index of the uplink channel. ; Spectrum resources allocated for one downlink channel .

[0020] In one technical solution of the present invention, time-slice resource allocation is performed on the LoRa gateway to achieve time-division multiplexing: The first LoRa terminal chip is divided into 25ms time slices, with a total of 40 time slices. One time slice is used to broadcast a sync packet at 470MHz for time synchronization. The other time slices are used to receive registration requests from TCP devices or BCP devices at 470.3MHz and to reply to registration responses from TCP devices or BCP devices at 470.6MHz. The second LoRa terminal chip is divided into 20 time slices, each 50ms in size. The gateway chip is divided into 20 time slices, each 50ms in size.

[0021] Through the aforementioned spectrum resource allocation and time slice allocation, each LoRa gateway can interact with... The TCP devices communicate bidirectionally once per second, enabling high concurrency and ensuring that each TCP device can communicate uplink with the LoRa gateway without time or signal conflicts. Each LoRa gateway can provide time synchronization services to countless BCP devices.

[0022] In one technical solution of the present invention, CRC verification is required for the sent data packets and data response packets: When the sender sends a data packet or data response packet, it calculates a CRC check value based on the packet header and payload, and fills the CRC check value into the end of the corresponding data packet or data response packet. After receiving the packet, the receiver recalculates the CRC check value based on the packet header and payload. If the recalculated CRC check value is the same as the CRC check value filled into the end, it indicates that the data is the same; otherwise, it is discarded. This realizes data verification, ensures data correctness and integrity, and avoids serious consequences caused by data errors or loss due to interference or abnormalities.

[0023] like Figure 3 In one technical solution of the present invention, both the TCP device and the BCP device include: an MCU, a third LoRa terminal chip, and a radio frequency front-end module; The MCU communicates with the third LoRa terminal chip via SPI, which is used to drive the third LoRa terminal chip to communicate with the second LoRa terminal chip in the LoRa gateway; The RF front-end module is connected to the third LoRa terminal chip to enhance the LoRa RF signal in the third LoRa terminal chip.

[0024] In one technical solution of the present invention: For outdoor scenarios, time synchronization with GNSS satellites is achieved through the GNSS module in the LoRa gateway. No radio frequency reachability and time synchronization are required between LoRa gateways. GNSS satellites are in the first level of simultaneous synchronization, and all LoRa gateways are in the second level of time synchronization, resulting in high synchronization accuracy. In indoor scenarios, the GNSS module in the LoRa gateway cannot find GNSS satellites. The server designates one LoRa gateway as the root node for time synchronization, which generates its own system time with a period of 1 second. Other LoRa gateways are assigned the address of their parent LoRa gateway by the server. During the broadcast of the first LoRa terminal chip of the parent LoRa gateway, the LoRa gateway switches to 470MHz to receive the broadcast sync packet of the parent LoRa gateway for time synchronization. It is necessary to ensure that the LoRa radio frequency signal can be successfully received between adjacent LoRa gateways.

[0025] like Figure 4 This invention provides a workflow for a LoRa-based wireless communication system, including: (1) LoRa gateway registration: The LoRa gateway sends registration information to the server, including the LoRa gateway ID, etc. At this time, registration from TCP devices and BCP devices is not accepted. Based on the configuration, the server specifies the broadcast time slice, channel group, and time synchronization method for the LoRa gateway; After successful registration, the LoRa gateway will begin periodically sending broadcast sync packets and will start receiving registrations from TCP devices and BCP devices.

[0026] (2) Registration of TCP devices and BCP devices: Outside of broadcast time, the first LoRa terminal chip in the LoRa gateway receives registration requests from TCP devices or BCP devices at 470.3MHz. Once received, it notifies the server via Ethernet or 4G / 5G. The server then authenticates and confirms whether the TCP device or BCP device can access the network. For TCP device registration, the server returns its communication time slice allocation index and uplink channel index, and informs the LoRa gateway of this information and caches it. The LoRa gateway replies to the TCP device with this information and system time through the registration response packet. For BCP device registration, the server returns whether the device is allowed to access, informs the LoRa gateway of this information and caches it, and the LoRa gateway replies to the BCP device with this information, along with the LoRa gateway broadcast time slice index and system time, through the registration response data packet.

[0027] (3) The LoRa gateway sends a broadcast sync packet to provide time synchronization service for the BCP device: After receiving the registration response data packet from the LoRa gateway, the BCP device completes the registration process and successfully synchronizes the system time. Subsequently, the BCP will adjust the index according to the actual broadcast from the LoRa gateway, opening the reception of LoRa gateway responses every cycle or every few cycles to perform system time synchronization and correction, thereby keeping the system time synchronization within the error range. (4) Bidirectional data communication between LoRa gateway and TCP device After receiving the registration response data packet, the TCP device completes the registration process and successfully synchronizes the system time. Subsequently, the TCP device will send uplink data according to the allocated time slice index and channel index, and receive the response from the LoRa gateway when the time slice index is incremented by 1. After receiving uplink data from the TCP device, the gateway chip of the LoRa gateway sends the content to the server via Ethernet or 4G / 5G. If the server has data to send to the TCP device, it sends it to the corresponding LoRa gateway. The LoRa gateway will first cache the data, and when the downlink data time slice corresponding to the TCP device arrives, it will send the data to the TCP device through the second LoRa terminal chip.

[0028] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A LoRa-based wireless communication system, characterized in that, include: TCP devices, BCP devices, LoRa gateways, and servers; The LoRa gateway is used to provide communication capabilities between TCP devices and servers, as well as between BCP devices and servers. The server is used to enable communication with the LoRa gateway; The TCP device is used to achieve reliable bidirectional data interaction with the LoRa gateway via LoRa; The BCP device is used to enable unreliable bidirectional data interaction with the LoRa gateway via LoRa.

2. The LoRa-based wireless communication system according to claim 1, characterized in that, The LoRa gateway includes: a gateway chip, a first LoRa terminal chip, and a second LoRa terminal chip; The first LoRa terminal chip is used to periodically broadcast sync packets, receive registration requests from TCP devices or BCP devices, and reply to registration responses from TCP devices or BCP devices. The gateway chip is used to receive data packets sent by TCP devices; The second LoRa terminal chip is used to send data response packets to the corresponding TCP device.

3. A LoRa-based wireless communication system according to claim 2, characterized in that, The LoRa gateway is allocated spectrum resources, including: 3 common channels, 8 uplink channels, and 1 downlink channel, wherein: The spectrum resources allocated to the three common channels are 470MHz, 470.3MHz, and 470.6MHz, respectively. Spectrum resources allocated to 8 uplink channels , Indicates the number of LoRa gateways. ; Indicates the index of the uplink channel. ; Spectrum resources allocated for one downlink channel .

4. A LoRa-based wireless communication system according to claim 3, characterized in that, Time-slice resource allocation is performed on the LoRa gateway: The first LoRa terminal chip is divided into 40 time slices, each 25ms in size. One time slice is used to broadcast a sync packet at 470MHz for time synchronization. The other time slices are used to receive registration requests from TCP or BCP devices at 470.3MHz and to reply to the registration responses from TCP or BCP devices at 470.6MHz. The second LoRa terminal chip is divided into 20 time slices, each 50ms in size. The gateway chip is divided into 20 time slices, each 50ms in size.

5. A LoRa-based wireless communication system according to claim 2, characterized in that, CRC checks are required on the sent data packets and data response packets: When the sender sends a data packet or data response packet, it calculates a CRC check value based on the packet header and payload, and fills the CRC check value into the end of the corresponding data packet or data response packet. After receiving the packet, the receiver recalculates the CRC check value based on the packet header and payload. If the recalculated CRC check value is the same as the CRC check value filled into the end, it means that the data is the same; otherwise, it is discarded.

6. A LoRa-based wireless communication system according to claim 2, characterized in that, The LoRa gateway also includes: an MCU, a GNSS module, and an interface module for connecting to the server; The GNSS module is used to provide PPS signals to achieve time synchronization of the LoRa gateway; The interface module for connecting to the server is used to enable data transmission between the LoRa gateway and the server; The MCU is used to drive the GNSS module, the interface module for connecting to the server, the gateway chip, the first LoRa terminal chip, and the second LoRa terminal chip to complete their respective functions.

7. A LoRa-based wireless communication system according to claim 2, characterized in that, Both the TCP device and the BCP device include: an MCU, a third LoRa terminal chip, and a radio frequency front-end module; The MCU is used to drive the third LoRa terminal chip to communicate with the second LoRa terminal chip in the LoRa gateway. The radio frequency front-end module is connected to the third LoRa terminal chip and is used to enhance the LoRa radio frequency signal in the third LoRa terminal chip.

8. A LoRa-based wireless communication system according to claim 5, characterized in that, Also includes: GNSS satellites and switches; The GNSS satellite is used to achieve global positioning of the LoRa gateway; The switch is used to enable communication between the LoRa gateway and the server, as well as to enable communication with the public network.

9. A LoRa-based wireless communication system according to claim 7, characterized in that: For outdoor scenarios, time synchronization with GNSS satellites is achieved through the GNSS module in the LoRa gateway; For indoor scenarios, the server designates one LoRa gateway as the root node for time synchronization. Other LoRa gateways are synchronized with the address of the parent LoRa gateway specified by the server. During the broadcast of the first LoRa terminal chip of the parent LoRa gateway, the LoRa gateway switches to 470MHz to receive the broadcast sync packet of the parent LoRa gateway for time synchronization.

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