Research And System Implementation Of LoRa-Based Internet Of Things

As a low-power WAN application specification based on LoRa,LoRaWAN enables LoRa-based IoT applications to be rapidly deployed and widely used.However,in practical applications of LoRaWAN,the reliability of the network is low,and the real-time communication cannot be guaranteed.Facing the problems of LoRaWAN,there is an urgent need for a low-power wide-area network based on LoRa with high reliability and real-time performance to meet the communica-tion needs of industrial Internet of Things and other applications.This topic con-ducts research on the above problems.The main research work of the paper is summarized as follows:(1)The LoRaWAN protocol was analyzed and a LoRa networking commu-nication method is proposed,the method that use TDMA and CSMA mixed access and air wake-up mechanism to achieve LoRa networking,which meets the trans-mission needs of different communication services and solves the increase in the number of node in LoRaWAN And the problem of decreased communication reli-ability due to increased communication conflicts when the amount of communi-cation data increases,ensuring that node have low power consumption while re-ducing communication delay.(2)Multi-channel communication method is used to effectively distinguish between TDMA and CSMA access methods by dividing different channels,and the number of channels is planned for different network requirements,which solves the problem of TDMA and CSMA mixed access communication when shar-ing channels Performance bottleneck.At the same time,the LoRa networking communication process including node access,message reporting and downlink wake-up has been formulated.Node is allocated to time slots of different TDMA channels through intra-network communication mechanisms such as channel allo-cation and time slot allocation to achieve reliable data for different node.Parallel transmission.(3)The design scheme of the corresponding LoRa IoT system is proposed.With the help of the Alibaba Internet of Things platform,the LoRa IoT system was build,gateway and node were connected to the Alibaba Internet of Things plat-form,corresponding access procedures and verification methods were developed to ensure safe and legal access to the device,and subscription/publishing using the MQTT protocol The model establishes instant,reliable remote communication services between users,cloud platforms,and devices.(4)According to the complex and diverse features of device functions in IoT applications,attributes,events,and services are used as the object model to ab-stractly describe the device,define the function of the device through the object model,and formulate users,cloud platforms,and devices based on the object model The data exchange protocol realizes the unified management of various LoRa heterogeneous devices.(5)The hardware and software design of the gateway and node was com-pleted.Raspberry Pi is used as the hardware platform of the gateway,SX1301 is used as the LoRa communication module to complete the data forwarding.Based on the multi-threading in Linux,the multi-threading is divided to complete the corresponding functions of the gateway,and the cloud platform is realized by transplanting the device-side SDK of the IoT platform.Access and communication;The design of the hardware part with the STM32L151CBU6 as the processor and SX1276 as the LoRa communication module was determined,The circuit design of the processor and peripheral circuits and LoRa communication circuit was com-pleted.On this basis,the LoRa RF driver and application are implemented pro-gram.This article takes the landscape lighting system as the application object,A system test platform was build to complete the LoRa networking communication test between the gateway and the node,and combines the Alibaba Internet of Things platform to complete the cloud platform access and communication of the gateway and the node and the overall function test of the system.The test results show that the network communication and the overall function of the system are normal,reaching the expected goal,meeting the application requirements of the landscape lighting system,and having application and reference value.