Surviving a disaster [optical communications

Abstract

The next-generation optical communications network, not surprisingly at all, will be as optical as it can be. Only optical dense wavelength-division multiplexing can provide the bandwidth elasticity that new emerging communications services demand. This is well understood, and despite an apparent slowdown in the world economy, multibillion-dollar commitments have been made to upgrade existing networks to next-generation DWDM. The next optical network is expected to be massive, yet flexible and ubiquitous. Current DWDM technology supports 160 wavelengths (in the C+L bands) per fiber; at 10 Gb/s this amounts to an astonishing 1.6 Tb/s aggregate bandwidth per fiber. Research has also demonstrated that ultra dense WDM (UDWDM) is possible, and it is a matter of time until 320 wavelengths (and a little later 640) will be multiplexed in a single fiber. As a consequence, we examine what the next optical network should be like, and proactively identify some areas that require special attention. One of the critical areas is service and network survivability not only when a node and/or link fails, but also when a cluster of nodes and/or links fail; that is, avoiding a disaster. Disaster avoidance has also become more important for both natural disasters and geo-political unrest.