WDM光网络的光路传输质量估计算法

在波长路由WDM光网中，信号在路由与波长分配算法(RWA)选定的光路上传输．传输过程中引入的各种串扰和噪声使信号的传输质量受到损伤，信号质量不断下降，目的结点无法正确有效地接收光信号。通过定义合理的结点和传输链路模型．提出了一种考虑线性传输损伤的比特错误率估算方法．在光路建立之前预先估计WDM网络中将要建立光路的传输质量，以此作为网络优化设计过程中RWA算法选路的依据。通过网络仿真和实验验证了算法的正确性。

Lightpath Transmission Quality Evaluation Algorithm in WDM Networks

In a wavelength-routed optical network,optical signal is transmitted over the entire optical lightpath assigned by routing and wavelength assignment(RWA) algorithm.While propagation through the network,the signal may degrade in quality as it encounters crosstalk and amplified spontaneous emission noise due to a number of fiber segments,passive and active optical components.Since these impairments continue to degrade the signal quality as it progresses toward its destination,the received bit error at the destination node might become unacceptably high.A novel attempt to evaluate network performance while taking into consideration the physical layer limitations was presented.The reasonable node and transmission link model were difind.Then a novel lightpath quality evaluation algorithm under linear impairment consideration was provided,which is used to estimate online BER on candidate routes and wavelengths before setting up a lightpath.The validity of the algorithm was validated by simulation and experiments.