Research On Routing Protocol With QoS Awareness In Heterogeneous Sensing Networks Of Agricultural Internet Of Things

The agricultural Internet of Things can provide remote monitoring capabilities for farmland management and agricultural operations,and users can observe crops and environmental conditions without being on the field.However,with the expansion of network monitoring area,the increased heterogeneity of Agricultural Internet of things and other factors make the guarantee of network quality of service(QoS)of data transmission face severe challenges.Aiming at the QoS requirements existing in the establishment of network data transmission path,this thesis comprehensively considers a variety of routing control indicators,optimizes the path selection mechanism,and improves the design of routing protocol to improve the network transmission performance.The main research work is as follows:(1)A prediction model of node energy consumption rate based on stochastic process is proposed.According to the different roles of nodes in the network,the node state transition process is modeled based on semi Markov process.Based on the state transition process,the node energy consumption evaluation indicators is designed,and three indicators of node energy state availability,energy factor stability and energy consumption service rate are extracted.According to the characteristics that the node state transition model only transfers on the discrete-time series,the discrete-time Markov chain is used to analyze the node state transition process to solve the energy consumption indicators,and the typical parameters are selected to numerically analyze the node energy consumption indicators of the model to obtain the performance change trend.(2)An adaptive routing protocol based on fuzzy logic is proposed.Firstly,this thesis analyzes the requirements to ensure the QoS of heterogeneous Agricultural Internet of things,puts forward the control indicators of routing QoS awareness,and utilizes the control indicators to design the routing table and routing control message structure.Secondly,according to the characteristics of routing control indicators,the indicators are classified and a fuzzy inference system is designed.The hop count and path distance are combined with the output interval,and the path link quality and path interference are combined with the output communication quality.Design a two-level fuzzy inference system based on the consumption rate and path heterogeneity to reduce the number of fuzzy rules and the complexity of the system.Then,in the process of route establishment,in order to make the source node have more optional paths,the destination node will generate and send different route reply packets for the same route request packet from different nodes.The route reply packet records the relevant path information.The source node caches multiple route reply packets received within the specified time,utilizes the fuzzy reasoning system to read the information in the route reply packet and calculate the relevant path quality.Thus,the source node selects the optimal next hop node based on the path quality.Finally,the routing control message exchange and update operations in the working process of the proposed routing protocol are summarized,and the complexity,correctness,integrity and overhead of the routing protocol are analyzed.(3)A simulation system of adaptive routing protocol based on fuzzy logic is implemented.Utilize NS3 to simulate and compare routing protocols.The system displays the simulation results of routing protocols through front-end and back-end interaction.The front-end interface utilizes Thymleaf module engine and Sematic UI framework.The back-end of the system utilizes the Spring Boot framework to design the view layer,control layer and business layer,and dynamically execute different NS3 Waf script files according to the command parameters passed by the frontend.Compared with the traditional routing mechanism research,the routing protocol proposed in this thesis shows better performance,with higher packet delivery rate and throughput,and improves the network life and reduces the end-to-end delay,which can provide good support for efficient data transmission in the heterogeneous environment of Agricultural Internet of things.