Research Of LoRa Multi-gateway Network Terminal Communication Collision Avoidance Algorithm

LoRa is a long-distance,low-power Wireless duplex communication technology.The terminal node can communicate with the gateway stably at a distance of several kilometers.With a reasonable parameter setting,the power of the terminal node can be sufficient for about four or five years.However,due to LoRa's long-distance transmission,the same gateway must transmit data with a large number of terminal devices,so the Communication conflict is inevitable between different terminals.Excellent communication collision avoidance algorithms can increase network data throughput and make network deployment easy.In this thesis,a communication collision avoidance algorithm that dynamically changes the terminal upload period is proposed in the LoRa communication network where multiple gateways cover the same area.This thesis divides the time into equal-length time slices,and stipulates that the terminal and the gateway can only communicate within the specified time slice,thus avoiding communication conflicts in the network.This thesis also proposes that the nodes in the network can dynamically adjust the terminal uploading data cycle by sensing the terminal load of the network,so that there is a dynamic balance between the communication frequency of each terminal and the base station and the number of terminal nodes under the gateway.Because there are multiple gateway repeated coverage situations,and the terminal upload cycle under each gateway node is different,this paper adopts a clever time slice allocation method to avoid waste of time slices due to different base station communication cycles in the repeated area.The communication processing scheme that allocates time slices to each terminal needs to synchronize the time of each node.In this paper,in the process of dynamically changing the terminal node's uploading cycle algorithm,a local wireless network is proposed to dynamically determine a base station node as the time synchronization reference point,and other communication nodes in the LAN are directly or indirectly related to the time reference point.Make time synchronization.In this way,the communication nodes of each local area network can synchronize with each other in normal time,thereby avoiding communication conflicts caused by the time being out of synchronization.