Digital World Tokyo | Terabit-class fat pipe delivers online movies in an instant

Terabit-class fat pipe delivers online movies in an instant

November 16th, 2007

When it comes to internet speeds, we’ve long-since consigned the humble kilobit-class connection to the dustbin, so a mathematics-based breakthrough has us wondering if megabit- and even gigabit-level connections will one day sound as quaintly archaic.

Researchers at Japan’s Tohoku University have tweaked existing protocols to enable standard fiber-optic cables to carry data at hundreds of terabits per second [Subscription link]. At that speed, full VOD movies could be downloaded almost instantaneously in their hundreds.

At the heart of the development is a technique already used in some digital TV tuners and wireless data connections called quadrature amplitude modulation (QAM). One glance at the Wikipedia explanation shows that it’s no easy science, but the basics of QAM in this scenario require a stable wavelength for data transmission.

As the radio spectrum provides this, QAM-based methods work fine for some wireless protocols, however the nature of the optical spectrum means this has not been the case for fiber-optic cables … until now.

The university team has solved the stability problem using a special laser that makes it feasible to pipe data down a glass fiber using the QAM method at blistering speeds. Although we shouldn’t expect to be choosing from internet connections rated in Tbps anytime soon, the development could one day make us look back on ADSL as fondly as we now do our 56K modems.

(Crossposted to Tech.co.uk)