Research And Improvement Of RPL Routing Protocol Based On Contiki Operating System

Wireless sensor network is composed of sensor nodes which have storage capacity,data processing and wireless communication function.These sensor nodes are randomly distributed in the target area,self-organized to form a multi hop network.The collected data of the target environment is transmitted to the gateway node through the network,so as to realize the real-time monitoring and real-time control of the target environment.However,the multi point to single point transmission mode is extremely easy to cause the imbalanced load in the network.This unbalanced load will cause some key nodes to run out of power prematurely due to heavy load,resulting in a blind spot in the network.Therefore,when designing routing protocols,load balancing mechanism must be added.In this paper,the following researches are carried out for the purpose of network load balancing:Firstly,the background of RPL Routing protocol is produced,and the reasons of load imbalance in RPL network is pointed out.Then summarizes the research status of RPL routing protocol load balancing improvement scheme.Secondly,the research platform Contiki operating system and its simulation tool Cooja are studied in detail.And then we study in depth about RPL routing protocol,including its control message,topology construction,routing process,objective function and routing strategy.Based on the in-depth study of RPL,the RPL routing protocol is simulated using the Cooja simulator,including networking test,Trickle mechanism testing,and network repair capabilities testing.By testing demonstrates the excellent performance and advantages of the RPL in Low Power and Lossy Networks.Thirdly,for the shortage of only a single routing metric in RPL routing protocol,this paper proposed an reliability energy balance routing algorithm.EETX classifies the remaining energy of the node and then combines the quality between the nodes.EETX not only ensures the reliability of the wireless link,but also takes the residual energy of the sensor node as an important reference for path selection,so as to achieve the purpose of energy consumption balance.Finally,this paper compares the ETX with the EETX proposed in this paper through the Cooja simulation tool.By comparing the simulation results of topology,node energy consumption and network lifetime,the feasibility and advantages of EETX are verified.