Submarine communications the new age of WDM connectivity

The emergence of optical amplification and SDH (synchronous digital hierarchy) terrestrial networks has opened up a new range of networking opportunities in the submarine systems domain with new (ring, meshed) architectures. In this paper we will show that WDM (wavelength division multiplexing) technology combined with optical amplification is preparing a new revolution of transoceanic networking. We will present the potentialities of the emerging 4 and 8 times 2.5 Gbit/s WDM systems in terms of architectures, and performances in transmission and routing. We will also present the mature enabling technologies that make possible the advent of submarine WDM systems with the right level of reliability at emission, reception and especially for WDM branching units (WDM BU). We will finally illustrate this evolution of the technology by experimental results obtained on straight line test beds and near term possible implementation.