Research Of Access Network Virtualization Convergence Networking

Access network is closely to customers, widely deployed with a variety of technologies. Access network plays a significant role for the Internet and its application, affects the work and life of people, the development of national economic and society. Among access ways, the fiber access that can provide great capacity and the wireless access that can provide high flexibility are considered as two promising access ways. Fiber access can provide enough bandwidth, low error rate and low interference, but the transmission path is fixed, less flixible. Wireless access can provide customers with a highly flexible, ubiquitous access, but the characteristics of wireless communication make data transmission rate limited and vulnerable to interference. In order to meet growing demand of Internet applications and realize advantages complement, fiber access network and wireless access network are combined, convergenced fiber wireless access network has become a hot research area around the world.A lot of works about fiber wireless convergenced access networking have be done, including network topology, convergenced node location selection, network deployment, the convergence of fiber subnetwork and wireless subnetwork, network routing, etc. However, the existing works adopt traditional networking idea. Especially, the networking method can not get rid of the technology details of fiber access and wireless access. Convergenced access network still faces three problems:the convergence of heterogeneous fiber subnetwork and wireless subnetwork, hard to guarantee quality of service and low network resource utilization.Aimed at these three problems, with the support of the National Natural Science Foundation of China, based on the basic principles of network virtualization, access network virtualiztioin convergence networking is conducted in this paper. The main works and innovations are listed as follows:1)To integrate fiber subnetwork with wirless subnetwork, a network virtualization based FiWi aceess network model is proposed which uses network virtualizatioin to shield the underlying heterogeneous network differences, migrates the service upon virtual network.Firstly, a network virtualization based FiWi aceess network model is proposed which uses network virtualizatioin to shield the underlying heterogeneous network differences, including the hierarchical model and the service model. The former depicts the relationships of abstracting and being abstracted, the relationships of requesting virtual resource and being requested virtual resource, among layers. The latter models the process from a service start to its end. The service is hosted by virtual network. Secondly, the characteristics of introducing network virtualization upon access network are qualitatively analysized. Thirdly, the influnce of introducing network virtualization upon throughput and bandwidth are quantitatively analysized. At last, through numerical simulation and SDN based experiment, it is proved that access network virtualization convegence networking is feasible, has a considerable networking performance, effectively reduces the RTT and improves resource utilization.2)As for the delay closely related to quality of service, the access network virtualization convegence networking solution based on small world model is proposed, using the LL in network to reduce delay.Firstly, MCC is used to model the small world feature in access network, considering the differences of a heterogeneous access network. Secondly, based on MCC, a virtual network mapping algorithm considering small world feature is proposed. Thirdly, the delay, limited value of wireless node number connected to a fiber node and the throughput of different types of nodes in a convergenced access netowrk are derived. At last, through numerical simulation, proposed networking solution based on small world model can effectively reduce APL, the delay between two farthest nodes, compared to Kleinberg model.3)To improve resource utilization, the multipath routing which uses redundant path can be exploited. But imbalanced multipath routing can lead to congestion and lower resource utilization. In order to improve resource utilization, a load balanced multipath routing is proposed. By exploiting the mesh structure of convergenced access network, the load balanced multipath routing is able to allievate network congestion.Firstly, introducing NSI that indicates the physical computational ability occupation and LSI that indicates the physical links bandwidth occupation, the resource occupation of the multiple paths hosting the same service is modeled. The sum of NSI square and LSI square is used to evaluate the resource occupation distribution in a convergenced access network. Secondly, the load balanced multipath routing in access netowrk vitualization convegence networking is model as a NLP problem and a load balanced multipath algorithm is proposed to achieve the even resource occupation in entire access network. At last, through numerical simulation, the proposed model can obtain better performances in the terms of multipath number, load balance property which is reflected by the stress fluctuation indicator, etc., compared with existing work.