Tutorial: the challenges of designing long-haul WDM systems

In the recent years advances in the capacity of commercially available systems has closely tracked research results, and the time between publication and commercialization of a new benchmark in capacity has been reduced from six years in the 1980´s to as little than two years today. In the previous years the classical approach to design verification was to build a model system and show that it works. In virtually all cases, this approach is no longer feasible. Time and money are critical in new system design, and full-length testbeds consume too much of both. The alternative to long testbeds for design verification is a process that uses loop experiments and computer simulations to test concepts and robustness of proposed designs. This tutorial will review key aspects of such a technique with an emphasis on transoceanic WDM systems. Specifics of long-haul terrestrial system design will be briefly discussed as well.