تخصیص توان نوری و سطح مدولاسیون در شبکه های نوری با لایه کنترل توزیع یافته مبتنی بر محاسبه مسیر متمرکز

The tremendous growth in the demand for high data-rates in optical networks makes efficient use of available bandwidth indispensable. Network s throughput can be improved by exploiting high-level modulation formats which allow the transmission of high data-rate and upgrading the quality of optical communication signal which degrades due to transmission impairments. The nonlinearity of optical fibers has been long recognized as one of the most overriding factors limiting the quality of optical communication signal. Accurate evaluation of nonlinearity in generalized multiprotocol label switching (GMPLS) optical networks is more complex and costly. In this paper, we present a novel heuristic joint routing, wavelength and power allocation method for path computation element (PCE) based architecture for GMPLS optical networks such that launch power of the lightpaths are updated continuously, thereby the minimum number of lightpaths are assigned to the demands. The Gaussian noise (GN) model is exploited to capture the nonlinear effect and we focus on maximizing the Shannon sum rate for network. In the DTG network compared to existing methods, numerical results demonstrate that the number of higher order modulation formats is increased and the network throughput is improved about 138.4 THz.