Dynamic Multipath Opportunity Routing Model And Its Stability Measurement For Cognitive Radio Ad Hoc Networks Under Contact Predicted

Spectrum resources become more and more nervous with the rapid development of wireless communication technology.Especially,as the high speed development of wireless local area network(LAN),zigbee and wireless metropolitan area network technology,people put forward higher requirements on broadband wireless application technology.The current spectrum allocation system rigidifies the ways and means of using the networks,and also contributes to the pressure of spectrum regulation and utilization,which is hard to meet the trend of the future intelligent network communication technology in itelligent,flood in and fusion.For example,cognitive radio(CR)technology can be combined with mobile Ad-hoc networks,which is called Cognitive Radio Ad hoc Networks(CRAHN).The spectrum-sharing based CR system has been identified as an efficient technology to change the operation mode of wireless networks from static state to dynamic adaptive state,which further solves the problem of spectrum scarcity and improves the adaptability of the existing wireless environment.However,it is difficult for SU to keep the real-time end-to-end routing due to the network topology dividing and the existence of network islanding in CRAHN.Relay nodes are usually needed to forward the packet to the destination node in the way of multihop storage carry forward and contact relationship predicted in dynamic routing patterns.Therefore,this paper adopts the method of contact predicted to describe SU contact relationship between nodes among different network islanding.In this paper,we do the following research works based on the features of CRAHN under contact predicted.Firstly,considering the network topology dividing and the presence of network islanding in CRAHN under contact predicted,as well as the dynamic nature of available spectrum,this paper puts forward a kind of dynamic multipath opportunity routing model based on the electromagnetic field and SNS(Social Networking Services).By using the distribution of the electric field line in electromagnetic field,this chapter decides the preliminarily trajectory of disjoint paths.Combining the knowledge of SNS and the mathematical formula of probability of encounter between nodes.Three important factors including centricity,similarity and trust in multiple social relations are associated with probability of encounter between nodes by chance connection rate.This chapter structures three related functions of three important factors by combining the characteristics of CRAHN,and then,multipath opportunity routing are determined on the basis of preliminarily trajectory of disjoint paths.The simulation results show that the proposed dynamic multipath opportunity routing strategy has good performance in the success rate and time delay.Secondly,this chapter defines a measurement method for link stability index.Secondly,this chapter proposes multipath routing dynamic rate allocation algorithm by combining path stability and prioritized traffic session.The algorithm considers different service performance parameters and introduces traffic sensing factor,then multipath routing dynamic rate allocation model is set up by combining path stability and differential game under the guarantee of the requirements for the flow rate in different traffic sessions.Simulation results show that the proposed algorithm could meet different QoS requirements of different services.