Stephanie A. Weiss, Executive Editor
If you need to produce X amount of work, you have two options: Hire a roomful of average workers to do pieces of the work, or hire a few fast, efficient people to do the same work. The fast workers will, of course, demand higher salaries; but the many average workers will require more training, more benefits, etc. The ultimate choice for a growing business is "Which method accomplishes the goal for the least expense?"
Most telecommunications network providers in the 1990s have chosen the fiber optic equivalent of the roomful of average workers: dense wavelength division multiplexing of 40 or more channels of information, each transmitting at 2.5 Gb/s.
But many photonics researchers and some network system providers believe that the 21st century solution lies in the telecom equivalent of a few fast, efficient workers: eight or 16 channels of information, each transmitting at 10 or even 40 Gb/s.
This combination of wavelength division multiplexing (WDM) with time division multiplexing (TDM) offers an interesting technical challenge for network system designers and component providers. The lasers and detectors for reliable 40-Gb/s transmitters and receivers are still several years from commercialization, but 10-Gb/s devices are available today.
Combining technologies also adds several twists to the economic equations of telecommunications networks, and the ease of untangling those twists will determine their ultimate viability in the open market.