Study Of PLI-RWA Algorithm Considering Multi-physical Impairments Parameters Constraint In All-optical Networks

With the development of the global information technology, a variety of traffics aregrowing rapidly in the network. Optical networks are in the evolution of a high speed,more dynamic and transparent architectures. In all optical networks, the transmission ofoptical signal from the source node through the whole lightpath to the destination noderemains in the optical domain and without the electric processing. As there is nopractical all optical regeneration, the effects of the physical layer impairments arebecoming more and more prominent. This can deteriorate the performance of dynamiclightpath connection and make a resource available lightpath becomes unavailable dueto the high bite error rate leaded by effect of the physical layer impairments. In order toensure the Quality of Transmission (QoT) of optical networks, the study of how tocircumvent the effect of physical layer impairments in RWA is very essential.This paper setting out from multiple physical impairments, analyzes the effects aswell as the diversity and complexity of the physical layer impairments in opticalnetworks, makes a further study of the key issue of the connections based on theconstrains of multiple physical layer impairments, focuses on the new RWA mechanismconsidering the physical layer impairments, designs a Q-factor estimation model basedon multiple physical impairments constraint and proposes a physical layer impairmentsaware multi-parameter and multi-constraint routing and wavelength assignmentalgorithm which can make it effectively to circumvent the effect of physical layerimpairments in establishing a new lightpath. The main works of this paper are asfollows.(1) Setting out from the evolution tend of optical networks, this paper summarizesthe issue of the key technology in optical networks. Based on the physical layerimpairments in optical networks, this paper introduces the research background, theresearch significance, the research status at home and abroad and discusses the necessityof the RWA algorithm research based on the physical layer impairments.(2) This paper describes the physical layer impairments and makes a furthertheoretical study of them. Explores the influence of the physical layer impairments tothe optical signal and makes a detailed analysis of the changes in the optical pulsecharacteristics as a specific physical layer impairment based on the simulation results. (3) This paper designs a Q-factor estimation model based on multiple physicalimpairments constraint. The estimation model can quantitatively calculate the physicallayer impairments more effectively especially the nonlinear physical layer impairmentsand more suitable in complex optical networks. It can calculate the effect of the physicallayer impairment more accurate so that it can help circumventing the effect of physicallayer impairments in establishing a new lightpath and make the optical networks withgood QoS.(4) At last, this paper proposes a PLI-RWA Algorithm Considering Multi-physicalLayer Impairments Parameters Constraint. In the algorithm framework, a costparameters integration mechanism is assigned and each link is assigned a vector of costparameters and the algorithm can be more effective to avoid the impact of the physicallayer impairments and also has a shorter average execution time.