How does Internet traffic travel across an ocean? These gadgets

IDG News Service | Dec 28, 2014

Optical submarine repeaters are big missile-shaped devices that lie along undersea cables carrying nearly all of the world's Internet traffic. We go inside the NEC plant that makes them.

While satellites were heavily used in the past, today 99 percent of trans-oceanic data traffic goes through cables. They lie up to 8 kilometers deep and can span distances of 13,000 kilometers.

In Otsuki, Japan, the iconic shape of Mt. Fuji looms large on the horizon.

But the city is also home to another landmark, and it’s a key part of the Internet’s infrastructure.

This NEC factory produces long, missile-shaped devices called optical submarine repeaters.

Their job is to boost data signals traveling through surprisingly thin fiber-optic cables that lie on the bottom of the ocean.

While satellites were heavily used in the past, today 99 percent of trans-oceanic data traffic goes through cables. They lie up to 8 kilometers deep and can span distances of 13,000 kilometers.

Weighing 200 to 700 kilograms, the repeaters are set every 40 to 100 kilometers to boost signals and check their integrity.

Some repeaters are Y-shaped and serve as branches in undersea networks. Others house seismographs and pressure detectors to sense earthquakes and tsunami.

To withstand the tremendous pressures of the deep for up to 25 years, the repeater electronics are housed in beryllium-copper alloy casings and sealed by electron beam welding.

Each casing is carefully polished in a clean room here, labeled with an ID number before it’s tested and then shipped to a cable factory.

Approximately 20 companies supply the main repeater components. About 80 workers at NEC’s plant turn out an average of 40 repeaters a month.

Web companies like Google and Facebook have been investing in undersea cables and as demand increases so does capacity. It’s now at 100 gigabits per second per fiber pair.

SOT
Shuji Yamashita
Vice President, NEC Yamanashi

“That’s the equivalent to 2,100 DVDs per second…that is the equivalent capacity….Next stage is 400G and more next stage is 1 TB per second.”

NEC is part of a consortium including Google working on the new FASTER cable system between Japan and the U.S. With six fiber pairs and 100 wavelengths, it will have a capacity of 60 Terabytes per second when it comes online in 2016.

As Google describes it, that’s about ten million times faster than your cable modem. It’s one more thread in the growing undersea web making the Internet faster.

In Otsuki, Tim Hornyak, IDG News Service