Analysis And Research Of Blocking Performance For The Flexible-grid Optical Networks

With the rapid development of cloud computing, internet of things and other evolvingtechnologies, the demands of traffic increased by leaps and bounds. The data rates of services are developed from 100Gb/s to 400Gb/s and 1Tb/s. The traditional fixed-grid wavelength division multiplexing(WDM)network with the fixed channel bandwidth,cannot allocate the bandwidth flexibly based on the actual requirement, which leads to a waste of the spectrum resources.The spectrum of the flexible-grid optical network is divided into the continuous spectrum slots, with the dynamically adjustable center wavelength and bandwidth.Different from the traditional WDM optical network, the flexible-grid optical network can allocate bandwidth based on the actual service’s needs. Depending on the service bandwidth and transmission distance, the modulation format can be adaptively selected,which can improve the resource utilization. The routing and spectrum allocation(RSA) in the flexible-grid Optical Network should not only follow the spectrum continuous constraints, but also the spectrum contiguous constraints. As a necessary technique to increase the flexibility and reduce the blocking probability, the spectrum conversion in the flexible-grid optical networks is similar to the wavelength conversion in WDM networks.However, because the spectrum converter is expensive, the efficient and flexible use of the spectrum converter is critical to reducing the cost of the networks.In this paper, we first introduce the advanced technologies in the flexible-grid optical networks in detail, and then simulate and verify the contribution of the flexible-grid, and study and optimize the configuration of the spectrum converter. Secondly, based on the research of the model of the blocking performance in the WDM network, we study the analytical model of the blocking performance for the sub-band conversion and the inverse multiplexing in the flexible-grid optical networks, and verify the feasibility and practicability of the analytical model. Finally, we introduce the software-defined network based on the Open Flow, and realize the simple traffic engineering on the simulation platforms of Mininet and POX.