Research On Energy Efficiency And Quality Of Service In Software Defined Fiber-wireless Access Networks

The global problems, such as the greenhouse effect and the energy crisis, are the major problems that restrict the development of society.The energy consumption of the access network take a large proportion of the telecom network, and energy-saving technology of access network has become an important research direction of the next generation broadband access network. The Fiber-Wireless Broadband Access Network(FiWi) possesses combines the features such as large-capacity, high rate, low power consumption of optical fiber with the ones of wireless access technology such as mobility, flexibility. The FiWi has become the most promising technology of the next generation broadband access network. With the continuous expansion of network scale, complex sercice surging and multi-level Quality of Service(QoS) guarantees, the higher requirements are put forward for FiWi network. However, because of the tight coupling of routing decisions and packet forwarding in the traditional network, the deployment of new technologies will result a highly complex network. The Software Defined Network(SDN) decouple the control and forwards of network node, and it finishes the deployment of network control algorithm, it implements a centralized and flexibility control of network traffic through software programming, and finally it achieve the enhancement of network energy efficiency and network performance.Based on the above reasons, this paper introduces the SDN in the FiWi network. In this paper, the architecture of Software Defined-FiWi Network(SD-FiWi) is proposed, and the energy-efficiency and network performance are studied base on the architecture. The major research results are as follows:(1) First, the concept of SDN is introduced in the FiWi network. The three-layer SD-FiWi network architecture is proposed. Based on this architecture, the infrastructure node construction and extensible econtroller, which support the Openflow protocol, are designed in detail. The various components of the controller functions are analyzed. The interactive of control layer and the infrastructure layer based on the Openflow protocol are described. The network architecture simplifies the complexity of FiWi network, effectively increasing the transmission capacity of the Fi Wi network traffic.(2) The study makes full use of centralized control functions of SD-FiWi network. The dynamic network domain dividing strategy and sleep strategy of network domain are deployed based on the SD-Fi Wi network architecture. The strategies take advantage of the global database in the network control layer to adjustment network domain dynamically, considering the load of gateways and network load balancing of inter-domain. It make the network service is concentrated in a special network areain a certain extent.And it freely manipulate network traffic through a specific gateway based on flow table, maximizing the sleep network domain to achieve energy saving in FiWi network.(3) The multi-level QoS mapping architecture in SD-FiWi network.Based on the dynamic network domain in SD-FiWi network, the deployment of QoS-aware routing in intra-domain androuting in inter-domainsmechanism is implemented. It considers the network gateway and link quality to implement the path selection of different levels services and sleep network control, fully guaranteeing the high-priority traffic of QoS.(4) In order to verify the scalable capacity of SD-FiWi network controller and further enhance the energy efficiency of the network, the controller and NC of flow table were extended in SD-Fi Wi network. The NC control process based on Openflow in SD-FiWi network is studied. Simulation results show that data transmission network based on NC in SD-FiWi network bring improvement in the aspects of network throughput and latency and others.