| Cognitive Radio Sensor Networks(CRSN)is a new research direction evolving from wireless sensor networks as a communication network with applications in multiple domains.Cognitive radio sensor networks can use spectrum-aware techniques to discover spectrum holes and communicate in an opportunistic manner,which can alleviate spectrum congestion.However,cognitive wireless sensor networks face the problem of limited energy resources of nodes at the same time.Therefore,this paper addresses the problem of energy constraint and spectrum resource shortage,and starts the research work from two perspectives of cluster routing algorithm and channel assignment method,the main work is as follows:In this paper,we first propose an event-driven channel allocation routing protocol based on the problem of unreasonable channel allocation in CRSN with the aim of reducing the channel switching frequency and extending the network life cycle.The protocol aims to improve spectrum utilization and reduce energy consumption.By selecting channels with low PU occupation probability,long idle time and high throughput,the node channels are paired using the Hungarian algorithm,and the optimal pairing result is calculated by a polynomial mathematical model.Distributed self-organized clustering reduces the energy consumption of the network.The gateway nodes and packet forwarding nodes are used for relay communication between clusters,which reduces data retransmission and improves routing stability without changing the communication range.Experimental simulations verify that the algorithm can improve the data transmission success rate,extend the network lifetime,and reduce the average end-to-end packet delay.Second,this paper proposes a spectrum-aware clustering routing algorithm based on bipartite graphs for the purpose of reducing network communication overhead and improving routing stability by addressing the problem of frequent clustering and generating too many clusters due to the presence of PUs in CRSN.The algorithm ranks the network communication channels according to the quality of the channels and assigns the channels considering the PU interference,and by considering the number of available channels,the quality of the channels and the number of neighbor nodes factors,the bipartite graph is used for clustering to ensure that the lowest available channel is satisfied within the cluster,and the optimal path is determined by considering the channel stability on the routing path,which reduces the frequency of channel switching and routing interruptions and improves the network lifetime.The algorithm is verified by experimental simulations to improve and enhance the packet delay rate,node energy consumption,packet delivery rate,and the number of clusters. |
