Research On Rendezvous Problem In Cognitive Wireless Sensor Network

Cognitive Radio Sensor Network is considered as a disruptive technological innovation that provides spectrum efficiency,it is widely used in military,environmental monitoring,forecasting,urban traffic and large-scale industrial park safety monitoring and other fields.With the rapid increase in the demand for wireless network services,the,ISM(Industrial,Scientific and Medical)band becomes very crowded,and the lack of spectrum has become an important bottleneck in the development of wireless networks.Therefore,Cognitive Radio Sensor Network has attracted extensive attention.In MAC layer,In order to solve the problem of decreasing the network life caused by the lack of public control channel in the dynamic change of cognitive radio sensor network,and the vulnerability of public control channel to interference attack,it is easy to reach the saturation bottleneck under large communication volume,and so on.This paper proposes a distributed Blind Rendezvous channel frequency hopping algorithm SRP,which divides node states into sending states and receiving states.The communication between nodes can be realized by adjusting the step size and using the probability parameters to generate the corresponding channel hopping sequence.The theoretical analysis shows that the proposed algorithm is suitable for clock synchronous / asynchronous model,symmetric / asymmetric model and multi-user / multi-hop model.Experimental results show that the SRP channel hopping algorithm is superior to other correlation algorithms in both the maximum encounter time(MTTR)and the average encounter time(ATTR).In the routing layer,the deployment of sensor nodes in cognitive radio sensor networks is usually rather dense and the energy of sensor nodes is limited.In order to solve the problem of cluster routing protocol in cognitive radio sensor networks,The extra overhead caused by frequent handoff channel and maintenance cluster may lead to low energy efficiency,short network life cycle and low throughput.In this paper,we propose a new clustering routing protocols,energy efficient clustering routing protocol(EECR)to select qualified nodes according to node location coordinates and residual energy preference.According to the weight of channel DTC stability and the residual energy of nodes,the cluster is clustered twice to achieve efficient communication within and between clusters,reduce the dynamic interference of the network,enhance the stability of data transmission,and improve the network life.Finally,the full text is summarized,and the future development direction is put forward.