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.