Another view of Data Transfer - Submarine Cable

cable routes

While researching privacy law regarding data transfer we wandered off course and found ourselves reading about submarine communications cable. It’s engrossing stuff and we thought you’d enjoy a few fascinating factiods.  And be sure to check out TeleGeography’s super cool interactive maps depicting the world’s telecommunications geography. 

:: Data travels on fiber optic cable

at an astonishing 99.7% of light speed

99 percent of international communications run on underwater cables.
It is a common misconception that satellites handle more traffic than they do, or are a more desirable technology.  Satellites are slow – sending signals back and forth from space takes time, and bandwidth is a problem.  Satellites are a good option when there is no fiber optic access available.

Laying submarine cable is a very costly business.
The nearly 300 cables we are commonly aware of are privately owned. Information about government owned cable is not readily available. The early transpacific fiber optic cables could cost well upwards of a billion dollars. These days it’s in the hundreds of millions.Traditionally cables were owned by huge telecoms and service providers, but now most cables are owned by consortiums.

:: 5 Milliseconds is a huge advantage to electronic traders,

well worth a $300 million price tag

Google and Facebook are big players, as are stock trading companies.
Google recently joined 5 other companies in a venture to run cable from our west coast to Japan. Data will travel at speeds 10 million times faster than your cable modem. 

Highest speeds are what financial traders are looking for.
In 2012 a new transatlantic cable was laid at a price of $300 million. By slightly optimizing the route from New York to London this cable is 310 miles shorter than the existing (perfectly fine) cable. The 310 miles translated to a 5 millisecond advantage which is HUGE in the world of electronic trading.

:: Repair requires splicing individual strands

of fiber optic as thin as a human hair

Cable Tapping -Spying and Surveillance.
Wiretapping has been taking place since the ColdWar when the USS Halibut located a Russian cable and installed a wiretap. The specially modified submarine returned every 30 days to pick up the stored info. Monitoring of data transmissions is still taking place, and in 2013 top secret details were leaked about US and UK spy programs that tapped and recorded all data transmissions flowing past. After revelations of US spying on Brazil and EU in early 2014, Brazil announced the construction of a new cable that would run directly to Europe, by passing the US hub that communications currently run through.

Cables are frequently damaged.
Severing a cable can have devastating effects so most countries have multiple communication pathways – if one is damaged the others can handle the traffic. When damage occurs a special cable ship goes to the area where the damaged portion is. How they retrieve the broken line depends on the depth of the ocean. 

Cable lays as deep as 26,000 + feet in some places. Robots can work at depths up to 6,000 or so feet. They find the damaged section and cut the cable. The robot brings both ends to the surface. In deeper water grapples hook the cable, cut it and haul it to the surface. The broken section is cut away and a splice is made. Each strand of the fiber optic bundle is thinner than a human hair and a special machine holds each strand and aligns it perfectly with a strand from the new section. Then a quick zap melds the two sections together.

Damage to cable occurs in many ways, and shallow water cable is most vulnerable. Natural disasters such as tsunamis and undersea earthquakes sever cable. The most common cause is commercial fishing e.g. trawlers scouring the ocean floor, and shipping activities e.g. anchors in shallower waters.

Recently the news was full of stories about sharks attacking Google's undersea cable and the measures Google was taking to prevent shark damage. The fact is, newer cables are being hardened to protect them from all sorts of damage. Metal sheathing and a kevlar material are used as some of the 8 or more layers that comprise a cable. And whenever possible cables are buried on the seabed, making them less likely to get snagged by an anchor or bitten by a shark.

Although they  are hardly a primary cause of damage, sharks DO attack cable. Its not uncommon to find shark teeth in undersea cable, and the munching could puncture older unhardened cable.