An effective integration of the PM 16-QAM modulation in enhanced metropolitan networks with the EDFA amplification

This paper deals with the integration of polarization multiplexed 16-ary quadrature amplitude modulation format in optical metropolitan networks enhanced with the signal amplification. Before expensive experimental setup or practical testing and demonstration, we prefer creating of appropriate simulation platform for the optical transmission system. A novelty can be found in adjusting, optimizing and construction of the proposed optical system and functional parts for any modulation format used. So, such simulation platform is first introduced along with possibilities for numerical simulations of its optical components - laser and amplifier. By this way, essential noise tolerances for comparison with the data under real conditions are included. Subsequently, there are characterized implementations of terminal devices in detail with a possibility for upgrading to the dual-polarization mode operation. Finally, simulation results from the simulation platform are presented and a discussion about demands for effective exploitation of the polarization multiplexed 16-ary quadrature amplitude modulation in enhanced optical metropolitan networks concludes our contribution.

Transmission challenges in metropolitan area optical networks

For implementing wide/metropolitan area network in optical fiber communication system the key technology that can be utilized is wavelength division multiplexing (WDM). We discuss the use of WDM in metropolitan networks along with its special feature of using optical add drop multiplexers and also design issues in implementing these systems. The issue of nonlinear crosstalk induced in metropolitan networks is considered in terms of power penalty. Also, the effect of dispersion induced in optical fibers is considered by using two types of transmission systems. One is considering the non-zero dispersion shifted fiber (NZDSF) in dispersion effected environment and second is, implementing dispersion compensation after normal single mode fiber (SMF + DCF). The effect of nonlinear cross talk which can limit transmission performance is discussed in both cases in context with different parameters like power penalty, frequency difference between signal & crosstalk and transmission distance etc.