$1.5 billion: The cost of cutting London-Tokyo latency by 60ms

Eugen Leitl eugen at leitl.org
Fri Mar 23 06:53:45 CDT 2012


http://www.extremetech.com/extreme/122989-1-5-billion-the-cost-of-cutting-london-toyko-latency-by-60ms

$1.5 billion: The cost of cutting London-Tokyo latency by 60ms

    By Sebastian Anthony on March 20, 2012 at 1:04 pm

Arctic Link submarine cable

Starting this summer, a convoy of ice breakers and specially-adapted polar
ice-rated cable laying ships will begin to lay the first ever trans-Arctic
Ocean submarine fiber optic cables. Two of these cables, called Artic Fibre
and Arctic Link, will cross the Northwest Passage which runs through the
Canadian Arctic Archipelago. A third cable, the Russian Optical Trans-Arctic
Submarine Cable System (ROTACS), will skirt the north coast of Scandinavia
and Russia. All three cables will connect the United Kingdom to Japan, with a
smattering of branches that will provide high-speed internet access to a
handful of Arctic Circle communities. The completed cables are estimated to
cost between $600 million and $1.5 billion each.

All three cables are being laid for the same reasons: Redundancy and speed.
As it stands, it takes roughly 230 milliseconds for a packet to go from
London to Tokyo; the new cables will reduce this by 30% to 170ms. This
speed-up will be gained by virtue of a much shorter run: Currently, packets
from the UK to Japan either have to traverse Europe, the Middle East, and the
Indian Ocean, or the Atlantic, US, and Pacific, both routes racking up around
15,000 miles in the process. It’s only 10,000 miles (16,000km) across the
Arctic Ocean, and you don’t have to mess around with any land crossings,
either.

Russian Optical Trans-Arctic Submarine Cable System (ROTACS) between UK and
JapanThe massive drop in latency is expected to supercharge algorithmic stock
market trading, where a difference of a few milliseconds can gain (or lose)
millions of dollars. It is for this reason that a new cable is currently
being laid between the UK and US — it will cost $300 million and shave “just”
six milliseconds off the fastest link currently available. The lower latency
will also be a boon to other technologies that hinge heavily on the internet,
such as telemedicine (and teleconferencing) and education. Telephone calls
and live news coverage would also enjoy the significantly lower latency. Each
of the fiber optic cables will have a capacity in the terabits-per-second
range, which will probably come in handy too.

Beyond the stock markets, though, the main advantage of the three new cables
is added redundancy. Currently, almost every cable that lands in Asia goes
through a choke point in the Middle East or the Luzon Strait between the
Philippine and South China seas. If a ship were to drag an anchor across the
wrong patch of seabed, billions of people could wake up to find themselves
either completely disconnected from the internet or surfing with dial-up-like
speeds. The three new cables will all come down from the north of Japan,
through the relatively-empty Bering Sea — and the Arctic Ocean, where each of
the cables will run for more than 5,000 miles, is one of the least-trafficked
parts of the world. That said, the cables will still have to be laid hundreds
of meters below the surface to avoid the tails of roving icebergs.

The ROTACS cable path

Each cable will be laid by a pair of ships: an ice breaker that leads the
way, and a cable ship. Until now it has been impossible to lay cables in the
Arctic Ocean, but the retreat of the Arctic sea ice means that the Northwest
Passage is now generally ice-free from August to October; a big enough window
that cable can be laid fairly safely. Existing cable ships (and there aren’t
many of them) are all outfitted for balmier climes, so all three cables will
require the use of a polar ice-rated ship that has been retrofitted to carry
cable-laying gear.

Read more about the secret world of submarine cables.

For more information on the Russian Optical Trans-Arctic Submarine Cable
System (ROTACS), check out the Polarnet Project (machine translated).

The Arctic Fibre and Arctic Link websites have information on the North
American cables.

[Image credit: New Scientist]



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