Research On Intelligent Agricultural Information Monitoring System Based On ZigBee

The development of agriculture information technology is an important means for enhancing agricultural productivity and boosting smart agriculture.In recent years,the extremely rapid development of ZigBee technology has been widely used in the agricultural field due to its advantages of low power consumption,low cost and low complexity.In order to monitor in real time the environmental factors of growth status of crops,this dissertation has set up a certain number of sensor nodes,which are arranged in a trial field for data collection and transferring them to the corresponding server.However,for ZigBee network,the transmission range of nodes,the battery energy,and the network bandwidth resources are very limited.Therefore,in many-to-one transmission mode way,the network congestion problems probably occur during data frequent transmission,which will seriously affect the overall performance of the network system.In response to this situation,this dissertation proposes to improve the ZigBee routing protocol in the network layer to relieve the network congestions considering energy and load.This dissertation first introduces the background and significance of the research and the development status of the ZigBee network.In addition,the causes of network congestion are briefly introduced,with the effects it produces and the corresponding control strategies.Secondly,the design principle and existing problems of ZigBee-based information monitoring system of Agricultural Internet of Things are described in detail.Finally,the ZigBee routing protocol is analyzed,and a newrouting protocol algorithm IMP-ZBR(Improve ZigBee Routing)based on the raw ZigBee routing protocol is designed.The algorithm includes :(1)for improvement of the intermediate nodes forwarding mechanism,the intermediate nodes make different decisions on the received RREQ(Route Request)messages according to their own energy levels and congestion statuses to filter out the nodes with lower energy levels and larger loads during the route discovery process;(2)for improvement of route selection basis,the amount of nodes energy,load,link quality and hops are comprehensively considered when updating routes,and thereby a path with the best comprehensive level is selected;(3)a cache path priority strategy is proposed during the path establishment phase,so that multiple paths are cached and the main path and the backup path are selected according to the priority of the cache paths.Therefore,the backup path can be switched to alleviate the congestion when the main path is congested.The NS2 simulation platform is used for validating the algorithm proposed in this dissertation,and the simulation results show that the proposed IMP-ZBR protocol is superior to the ZigBee routing protocol in overall performance and relieving congestion to some extent,reducing the average end-to-end network delay:44 ms,increasing the packet delivery rate: 4.5 %.