The Research Of QoS Routing In Cognitive Network

Cognitive network is a network with a cognitive process that can perceive current network conditions, and then plan, decide and act on those conditions.The network can learn from environment and adapt to new environment, all while taking into account user's end-to-end goals.The realization of cognitive network related to a number of key technologies, including routing technology. As one of key technologies, routing in cognitive network mainly focus on designing a routing machnism which can sense the context information of network and characteristics of self-adaptation, self-optimizing.This paper firstly analyzes the demand of cognitive network routing technology. Considering QoS routing as one of the most important mechanisms in network end-to-end QoS guarantee mechanism, QoS routing was introduced to cognitive network and a cognitive network QoS routing algorithm is proposed based on the adaptive ant colony algorithm,the proposed algorithm is simulated in an example topology.Taking into account of the cognitive network routing algorithm should make full use of network information awared by cognitive network and OSPF protocol is the most widely used link state routing protocol. The paper expands OSPF protocol to including bandwidth and delay as the link state information.Combined with adaptive ant colony algorithm, a source routing scheme based protocol called OSPF-AAS was proposed in the paper.Then, the proposed routing protocol OSPF-AAS is simulated throuth network simulation software NS2, its performance is compared with the traditional OSPF protocol.Finally, the OSPF-AAS protocol is realized based on the XORP open source routing platform and deploied in the cognitive network prototype system to verify it's function.Results show that OSPF-AAS routing protocol can effectively avoid congestion, balance network load and improve utilization of network resources.Therefore, it in line with the needs of cognitive network.