A Study Of Efficient Routing And Spectrum Allocation In Elastic Optical Networks

Optical network is moving toward dynamic and flexible volume of data with the rapid development of the Internet business, such as HD video, cloud computing, streaming media. Compared to traditional Wavelength Division Multiplexing(WDM) networks, the flex-grid elastic optical network(EON) has a high spectral efficiency and flexibility of spectrum allocation, and becomes a hotspot recently. Based on the characters of width variable in EON, the objective of this thesis is to reduce the complexity of switching nodes and to save energy consumption, and we study the routing and spectrum allocation(RSA) in several aspects as follows:Firstly, aiming at the problem that service request does not match the rate of optical path, we studies the optical traffic grooming based on Sliceable bandwidth variable transponders(SBVT) from the view of energy consumption. We give the integer linear programming(ILP) model including the routing assignment. By the simulations and comparisons, the results shows that optical grooming with a certain sliceable ability of SBVT can effectively reduce the energy consumption.Secondly, in view of the limited exchange dimension of optical cross-connect(OXC) devices in the optical networks. The thesis proposes a route, spectrum and waveband assignment(RSBA) algorithm based on a novel OXC architectures utilizing waveband switching technique, by using the function of path contains to denote the mapping relationship between demand light path and waveband channel. The results shows that the proposed algorithm can effectively reduce the number of optical switch port at the expense of a small amount of spectrum resources compared with the traditional non-waveband switching algorithm.Lastly, aiming at the problem of increasing the number of optical switching ports in the elastic network equipment with SBVT, we propose an ILP algorithm based on the waveband switching. The simulation results show that the proposed ILP algorithm can significantly increase the network capacity or effectively reduce the optical switching port number than traditional one.