Research On WDM Optical Networks Resource Allocation Mechanism Supporting Quantum Encryption Services

Quantum key distribution(QKD)technology based on the basic principles of quantum mechanics can realize the absolute security of information in the theory of confidential communication.At present,point-to-point QKD technology has made great progress.Integrating QKD technology with the existing WDM optical networks is the key to further promote the practical application of QKD technology.In the converged optical networks,it needs to solve two problems:1.how to reduce the influence of noise on the transmission of quantum signals;2.how to effectively solve the resource competition between quantum signals and classical signals.In view of the above problems,this thesis studies on the resource allocation mechanism of quantum signals in single-core static optical networks,single-core dynamic optical networks and multi-core static optical networks.This research consists of three parts:(1)Proposing a time-wavelength-fragment-based QKD(TWF-QKD)scheme for single-core static WDM optical networks and designing a heuristic optimization algorithm based on Tabu search to solve the constructed time-wavelength-fragment mathematical model.The traditional fixed wavelength assignment scheme only considers the assignment of fixed wavelengths to quantum signals,which makes resource competition between quantum encryption services and classical services.Unlike classical services,quantum encryption services can use time-wavelength fragments in the network to generate quantum keys.This solution is based on Quantum Key Pool(QKP)and trusted relay technology,and makes full use of the known time-wavelength fragments in the static network to transmit quantum signals to solve resolve resource competition between quantum signals and classical signals in a converged networks.Compared with the traditional fixed-wavelength-based QKD(FW-QKD)scheme,the simulation results show that this scheme can meet the requirements of networks quantum encryption while minimizing the blocking rate of classical services.In addition,in order to reduce the solving time of the mathematical model of this scheme,this thesis proposes a heuristic optimization algorithm based on the Tabu search algorithm.Compared with the traditional Mixed integer linear programming algorithm,it can obtain a satisfied solution while greatly reducing the solution time and solution time can be reduced up to 146 times.(2)Proposing an optimal quantum channel prediction scheme based on machine learning for a single-core dynamic WDM optical networks.The noise generated by classical signals in dynamic networks is time-varying,this makes traditional fixed wavelength allocation schemes unable to guarantee that quantum channels are always affected by lower noise..This thesis proposes an optimal channel prediction scheme based on the LightGBM algorithm,the prediction accuracy of the optimal quantum channel in the 4-node,6-node and 14-node networks topology can reach 95%,90%and 86%respectively.(3)Proposing a fiber core allocation scheme capable of reducing the influence of inter-core crosstalk on quantum signal for the multi-core static WDM optical networks and designing a heuristic optimization algorithm based on Genetic-Tabu search to solve the constructed time-wavelength-fragment mathematical model.Inter-core crosstalk noise in multi-core optical fibers will cause great interference to the transmission of quantum signals.However,the traditional outward-to-inward core allocation scheme does not optimize the allocation of classical signals and quantum signals in the core dimension,this reduces the network resources available for quantum signals.In response to this problem,this thesis proposes a heuristic core distribution schemes which can reduce inter-core crosstalk noise,for the simulation results show that when the core coupling coefficient is in the range of 10-6～10-9,the quantum key generation rate of this scheme is higher than that of the traditional fiber core distribution scheme,which can increase up to 59%.Moreover,the simulation results indicate that the heuristic optimization algorithm based on Genetic-Tabu search algorithm can effectively reduce the solution time of the mathematical model of time-wavelength fragments while stably obtaining a satisfied solution in the multi-core static WDM optical networks.