Exploding bandwidth demand lays new ground rules for testing fiber optic networks and components.
Joachim Vobis, Agilent Technologies Inc.
During this decade, the telecommunications industry has been making a transition from a slowly growing network optimized for voice traffic to one whose bandwidth needs are exploding to keep pace with data exchange between computers. Fiber optic communications systems depend on the latest advances of optical components and ultrahigh-speed semiconductors, as do test equipment manufacturers.
Communications system designers are aggressively pushing the limits of existing technology to new heights. On the modulation side, 40- Gb/s links are in development, with 10 Gb/s moving into manufacturing and 2.5 Gb/s almost a commodity item.
On the optical side, wavelength division multiplexing (WDM) at 200 GHz or wider spacing with up to eight channels is considered "classic," and 32 to 64 channels spaced at 100 GHz are commonly available. Meanwhile, engineers are developing systems with 50-GHz spacings and more than 120 channels, and researchers are already aiming at 25-GHz spacing and better.