Optimization Of WDM-PON Transmission Technology

In recent years, with the rapid development of multimedia services, full-service access for network bandwidth needs are also increasing, the conventional cable-media access network technologies inevitably bring about the last kilometer of the bandwidth bottleneck. Optical access network has become the final solution to solve this problem. WDM-PON network advantage merger WDM(Wavelength Division Multiplexing) and PON(Passive Optical Network) topologies, making it a high-performance, next-generation potential access networks, WDM-PON network bandwidth with its rich resources, good anti-noise performance advantages has become a hot research in the 21 st century.This thesis analyzes the RBN(Rayleigh Backscattering Noise) generated by the implementation process of the colorless WDM-PON technology, as well as the elimination of the RBN become the major research programs, subsequently, under ruling out the premise of the dispersion system interference, this thesis analyzes the wavelength assignment algorithm, and propose a new wavelength assignment algorithm.Firstly, the thesis studies the implementations for the colorless ONU(Optical Network Unit) in the WDM-PON system, and two existing programs(spectral partitioning scheme, then modulation scheme) were compared, and then analyzes the modulation scheme to achieve colorless ONU of the WDM-PON systems, and two modulation device(RSOA, MZM) to achieve a colorless ONU of the WDM-PON system of performance analysis.Secondly, the thesis summaries the generation principle of the RBN in the WDM-PON network, on the basis of comparison of two classic eliminate RBN program currently used to design a ring type WDM-PON structure, the structure using the FBG(Fiber Bragg Grating) and OC(Optical Circulator) features to eliminate RBN, and simulation of the ring WDM-PON structure can eliminate the RBN, so as to achieve the purpose of improving the system transmission performance.Finally, on the basis of eliminating the Rayleigh scattering the simple dynamic wavelength assignment algorithm was improved in the WDM-PON system, and a new dynamic wavelength assignment algorithm is put forward. The simulation analysis was carried out on the two algorithms. This new algorithm can solve the problem of the total number of wavelengths less than the total number of access users, and this new dynamic wavelength assignment algorithm can distinguish between the actual network traffic levels, and have a reasonable allocation system wavelength.