Research On MAC Layer Protocol Of Water Leakage Trigger Network Based On LoRa Wireless Sensor Network

At present,China's total water resources are seriously insufficient,and it is increasingly becoming one of the important reasons that affect the economic development and social progress.Feed piping is the lifeline of urban development but pipeline leakage accounts for 50% of the weight of total water loss.Therefore,how to find the leakage point in time when the pipeline is leaking has become the key problem of effective protection of water resources.Therefore,with the flexible self-organizing network of the wireless sensor network,the ability to arrange a large number of nodes and mixed hop transmission in the network,a water supply pipeline network capable of real-time monitoring data can be constructed,which has great value to control the leakage rate of the pipe network.Because of the special environment of water supply network,each wireless sensor network node is located underground,so it is impossible to charge it;How to improve the network throughput,reduce the number of retransmissions,save energy consumption and prolong standby time are the focuses of this paper.Urban underground pipelines are widely distributed,but the traditional wireless sensor network has a single hop distance of only a few tens of meters,which leads to thecomplexity of routing protocol,increasing the network overhead and reducing the Standby life of sensor nodes.This paper deeply studied the above problems.The main research idea of the paper is: replacing the traditional wireless sensor by a new sensor LoRa node with long distance and low power consumption.Aiming at the shortcomings which is no channel anti-collision mechanism and no Back-off algorithm after collision of ALOHA and ClassA MAC layer protocols adopted by LoRa nodes,the paper proposes an adaptive P-CSMA code division multiple access protocol.The protocol firstly adapts the P-CSMA protocol with good throughput under high traffic,making use of the idea of CDMA to embed the orthogonal spread spectrum code and realize code division multi-channel transmission.Secondly,it adds the Back-off algorithm of adaptive P.According to the collected parameters,the channel is divided into four stages: light load,moderate load,heavy load and heavy load making the channel can dynamically adjust the size of P value with the size of the load.The improved protocol has better flexibility and real-time performance.Through the OPNET simulation experiment,the results show that under high traffic,the proposed improved MAC layer protocol has higher throughput and lower delay.Therefore,the protocol proposed in this paper is more suitable for underground leakage pipe network system than the traditional protocol.