Resaerch On Resource Optimization Technology For Optical Networks

With the rapid development of Internet, especially mobile Internet, many of network service, such as mobile applications, cloud computing and internet video, have been widely used these years. The optical network, as the core network in data transmission, calls for larger capacity and higher flexibility. Nowadays, we can find that the wavelength-division multiplexing (WDM) technology cannot meet the demand of high bandwidth and high flexibility, which makes elastic optical networks (EON) become a hot topic in the research of optical network technology. While making the spectrum resources more flexible may cause the growing problem of the spectrum fragmentation problems. The resource optimization problem in EON has become an important topic and needed to be solved immediately.This paper focuses on the key technologies in resource fragmentation and routing and spectrum allocation (RSA) problem. We present a traffic-aware fragment degree (TAFD) method to evaluate the fragment degree of the network. TAFD shows a quantitative way in how the different network can "tolerant" fragment. We also use a dynamic queue model to make the calculation of traffics’probability easier. The simulation results show that, the value of TAFD can perfectly reflect the fragment degree of the network.Secondly, by using TAFD in routing strategy, we propose a RSA which can reduce the degree of fragmentation when set up a light path. According to the simulation results, less fragments appear in the network by using fragmentation-aware RSA. So that the network can accept more connections because of the lower network blocking probability.Also, we design a software defined network (SDN) model based on path computation element (PCE) to optimize control technology in EON. The great feature of centralization and flattening in SDN make it possible to improve the utilization of resources in large scale network and reduce the network delay time caused by control technology. At last, we completed the construction work of network experiment platform cooperated in group.