Research On Clustering Routing Algorithm For Cognitive Radio Sensor Network

Cognitive radio sensor network(CRSN)is a new type of network that introduces cognitive radio(CR)technology into wireless sensor network(WSN).CRSN can not only alleviate the congestion of unlicensed spectrum,but also improve the utilization of licensed spectrum.However,CRSN also faces the challenges of high cost and high energy consumption.To address these challenges,this thesis proposed a heterogeneous cognitive radio sensor network(HCRSN)with the separation of cognitive nodes and data nodes.Hierarchical routing based on clustering has great advantages in network topology control,reduction of network energy consumption and reduction of redundant data.However,the clustering routing algorithms in traditional WSN and CRSN cannot be effectively applied to HCRSN.Therefore,a clustering routing protocol suitable for HCRSN needs to be designed according to the network characteristics of HCRSN.The main research work and innovative achievements of this thesis are as follows:1.This thesis introduced WSN and CRSN,briefly describes the application of CRSN and clustering routing algorithms in WSN and CRSN.2.Based on the network characteristics of HCRSN,this thesis proposed a low energy adaptive clustering routing algorithm,which can be effectively applied to HCRSN.Firstly,based on the working time sequence of nodes in HCRSN,this algorithm deduces the optimal number of clusters that can minimize the network energy consumption on the premise of ensuring the channel detection probability of each cluster is high enough.Then the algorithm effectively balances the distribution of the cluster head in the network,the distribution of cognitive nodes in the cluster and the energy consumption of the cluster head through the cluster head selection criterion and the cluster member clustering criterion.Simulation results show that compared with traditional WSN and CRSN clustering routing algorithms,HLEACH algorithm has better performance in such aspects as average channel detection probability,network lifetime,distribution balance of cognitive nodes in clusters and energy consumption balance of cluster heads.3.After proposing the time-triggered HCRSN clustering routing algorithm,this thesis further proposed the HEECR clustering routing algorithm based on the event-driven HCRSN.This thesis first analyzes the main research content of event-driven HCRSN clustering routing protocol,and then formulates the corresponding algorithm according to the research content.In the HEECR algorithm,events in the network area will trigger the data nodes,and the activated data nodes will activate the surrounding cognitive nodes through control packets.All activated cognitive nodes will be involved in the election of the cluster head according to their residual energy and their average distance to all activated data nodes.Cognitive nodes with more residual energy and shorter average distance will be selected as the cluster head.Then the cluster head activates the cognitive nodes from the cluster head to the Sink nodes through the node activation algorithm.Finally the Sink node decides the routing.