Research On Amplifiers Placement And Wavelength Conversion Strategies For C+L-band Optical Networks

In recent years,with the development of new information technologies,such as 5G,AI,and AR/VR,the Internet network traffic has grown rapidly,brings great challenges on the backbone network which is based on optical networks.To this end,it is necessary to expand the bandwidth of the existing optical network.Considering the cost-effective advantages of multi-band technology,operators would prefer to adopt the multi-band optical transmission technology,which can extend the bandwidth more than 10 times.Due to the crosstalk between different bands,the current research on multi-band optical transmission mainly starts from the C+L band optical network.This paper focuses on the optimal design of C+L-band optical networks,specifically on the placement of L-band amplifiers in C+L-band elastic optical networks and wavelength conversion in C+L-band WDM optical networks.For the amplifier placement problem in the C+L-band elastic optical network(EON),a Mixed Integer Linear Programming(MILP)optimization model is proposed and three L-band amplifier placement strategies are developed,including joint placement(JP),independent placement(IP)and mixed placement(MP)strategies.At the same time,this thesis also addresses the routing,band,modulation format and spectrum assignment(RBMSA)for C+L-band elastic optical networks and efficient heuristic algorithms are proposed.The simulation results show that the MP strategy can effectively achieve a tradeoff between network spectrum utilization efficiency and L-band amplifiers placement cost.Specifically,the network spectrum utilization efficiency of the proposed MP strategy is close to the performance of the IP strategy,but its L-band amplifier placement cost is close to JP strategy.Furthermore,the proposed RBMSA algorithm is very efficient to obtain almost similar performance with the MILP model.For the wavelength conversion problem in the C+L-band WDM optical network,three C+L-band wavelength conversion strategies are proposed,including intra-band wavelength conversion strategy,inter-band wavelength conversion strategy and full-band wavelength conversion strategy.At the same time,the corresponding C+L-band optical switching node architecture is also developed for each wavelength conversion strategies.To compare the performance of different wavelength conversion strategies,two routing,band,and wavelength assignment(RBWA)algorithms are developed,including the shortest routing based RBWA algorithm and the waveplane based RBWA algorithm.The dynamic demand simulation model is employed to simulate the network lightpath blocking performance of different RBWA algorithms.The simulation results show that the network lightpath blocking performance of the intra-band wavelength conversion strategy is very close to that of the full-band wavelength conversion strategy,and is much lower than that of the inter-band wavelength conversion strategy.Furthermore,the waveplane-based is very efficient and can significantly improve the network lightpath blocking performance compared with the shortest routing-based RBWA algorithm.