Research On Optimization Strategy Of Transmission Quality To The Links In Impairment-Aware Optical Network

With the continued and rapid growth of optical transmission network and emergence of various new types of communication services, people are continuously putting forward higher requirement for capacity, rate and intelligent degree of communication network. Its core processing mechanism will be more and more widely applied to life. The optical network is gradually becoming a transparent optical transmission network with high transmission capacity, strong processing ability and good economic benefit. Due to the continued increase of optical network’s pressure of bearing services, with the increase of transmission distance of optical link, there will be phenomenon of physical impairment accumulation of transmission signal. In order to satisfy and optimize the transmission performance of light path while constructing the path flexibly, the optical transmission network is required to have intelligent feedback and coordinated control mechanism based on impairment awareness of transmission signal, so that we can dynamically adjust the tunable optical devices and performance parameters in the link and then improve transmission quality of the whole optical network link.The main research content of this paper is as follows:1. In flexible transparent WDM (Wavelength Division Multiplexing) optical network, physical impairment of optical signal generated in the transmission process will accumulate continuously and then affect transmission quality of signal. Aiming at the above problem, based on Impairment-Aware mechanism, in this paper, we studied the impairment compensation strategy under the effect of feedback control. We used tunable devices for dynamic power control on node equipments in transmission link, thereby we can control the network online from the receiver to the transmitter, and then we can adjust parameters of transmission performance state of link. After setting compensation, optical signal-to-noise ratio (ONSR) of optical transmission link is better than original, at the same time, it also meets the minimum permissible range of optical signal-to-noise ratio (ONSR). Through the simulation results, we can see the introduction of controlling means is effective and feasible. After controlled, OSNR satisfied the requirement of transmission performance.2. In order to effectively optimize the transmission performance of optical network signal further, in this paper, we studied the strategy of adjustment and control to deal with channel power of optical transmission link and further improve the optical signal-to-noise ratio. We mainly adopted genetic algorithm and nonlinear control strategy based on impairment awareness to search the optimal value which meets the demand of conditions in the search space. We can adjust and control parameters of optical link through the tunable optical device to improve the optical signal-to-noise ratio and optimize the quality of signal. The controller shows good dynamism to adjust and compensate transmission power and has better stability and better ability of feedback and adjustment.In this paper, we set up optical link model to solve the problem of optimization of transmission quality and dynamically adjusted the end-to-end performance of adjustable compensation devices in the link. We used means of feedback and genetic-nonlinear algorithm to control the power of link and optimize target of transmission performance such as ONSR. In this paper, we simulated under the minimum permissible limitation requirement of OSNR. The result of simulation showed that after controlled and given feedback, OSNR of each node in the optical link was able to get better optimization.