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Net Insight cuts GPS cord for time synchronization

In the late 1990s, when "interactive online multimedia" was mostly a gleam in its boosters' eyes, optical transport networking company Net Insight got its start as a research project between Ericsson and Swedish Telia.

"The focus then was building optical networks for media-centric networks," said Net Insight founder and VP of business development Per Lindgren. "ATM was big, but it was too expensive, and it didn't fly. In Sweden, IPTV was big, and fiber to the home was subsidized. The question was: Now that we have the high bandwidth, what do we use it for? The obvious answer is video." And the more quality video people get, the more they want.

That observation combined with the 2001 tech bust prompted Net Insight toward the needs of the media industry. "Media wasn't as affected as the telecom industry," Lindgren said. "We focused on the needs of both media and content owners. Our network was created by people coming from both media and telecom worlds."

Now Net Insight is focused on helping operators take advantage of the new business and service opportunities opened up by digital TV — Lindgren calls it the media-centric multiservice network. The newest feature of the company's Nimbra platform, GPS-independent time synchronization, gives operators a synchronization alternative that Lingren says will reduce opex and capex, and allow them to carry more channels (as many as 20 percent more) over spectrum they already have.

"More and more networks are single-frequency networks," Lindgren said. "If you look at the different standards for mobile and DTV, most are relying on single-frequency networks to save spectrum. Nimbra's GPS-independent synchronization adds time as an additional service. Instead of [communicating with] a satellite, you put an atomic clock in the network and distribute the time. It saves money, and no GPS receiver — an extra dish — is needed."

Nimbra's approach also simplifies local ad insertion, something that's very important to TV broadcasters. "A more flexible terrestrial network opens up that capability," Lindgren said. Plus, the terrestrial network also simplifies interactive services. "Satellite [communication] adds a lot of extra cost to interactive," he said. "We also see in some installations the uptake is greatest among younger people — and they're accustomed to interactivity."

GPS has other limitations, Lindgren said. "It's used in military operations. If there's a crisis, the accuracy of GPS can be turned down, so you may lose synchronization when it's most needed. Plus, GPS can be jammed." As a result, some countries are now asking for GPS-independent time synchronization for public TV services.

Currently, Net Insight has half a dozen customers using the new time transfer capability, with one installation currently using 300 transmitters and planning to add about another 200 when the system is fully built out.

"We developed the time transfer function for our DTV customers," Lindgren said, "but it's been a strong feature for us in the mobile TV market."