Research On Service Assurance Methods Of Cognitive Wireless Network

Cognitive wireless network with dynamic spectrum accessing as key technologies,is the result of cognitive network,network,Mesh network access technology integration and development of.Cognitive network is the best way to achieve integration of heterogeneous networks,efficient use of network resources and satisfied End-to-end services of user.As the instinctive attribution,the cognitive ability is the prerequisite of implementing cognitive process.Due to the complicated network structure,nodes mobility,etc.,there are various challenges existing in all the parts of cognitive process.For the optimization of access resources,the main work is summarized as follows.(1)End-to-end delay and transmission delay are difficult to estimate accurately,and the existed approaches,designed based on such delay parameters,have very limited reality.Thus,the retransmission probability is introduced to the network optimization utility.Retransmission probability can be estimated by the number of retransmissions,and does not require complex calculations and analysis.Moreover,a MIN-MAX model for network utility is established and also attains an approximate optimal solution by means of a regular game tool.(2)Global information sharing,users scale limitation and single decision parameter are main disadvantages existed in access network selection approaches.An approach for access network selection based on finite population game is proposed,in which the problem of access network selection is described as a finite population game model,and each population strategy evolution is proved to be a random birth-death process.Accordingly,the selection algorithm is presented based on Markov process,and the local update mechanism is improved from a multi-strategy perspective,which is used to reveal the revolution mechanism of selection strategies.(3)To guarantee the cognitive ability of networks,we have proposed a defense strategy for Objective Function Attacks(OFA)based on Differential Game theory.The process between attackers and defenders is described by a differential game model,which is accordant to the real scenario.The proposed approach could achieve a low latency caused by centralized monitoring in a manner of distribution.In conclusion,this work will pay more attention on the fast channel sensing,transmission guarantee under high rate of bit error,access selection of heterogeneous networks and cognitive ability guarantee according to the basic cognitive process.