Google lives in an Orange submarine: Transatlantic cable will get by with a little help from some friends Orange and Telxius are hooking up to provide backhaul links and co-lo services for Google's fibre-optic transatlantic cable, due to go live later this year. The Dunant cable will leave from Saint-Hilaire-de-Riez in the Pays de la Loire region of northwestern France and after a 6,600km Atlantic crossing it will land at Virginia …
...charging you by traffic. 10 bucks per gigabyte, say.
And it can pump 250 terabits per second into customers. That's how much money 4G telcos are making here in South America.
A license to print money.
/rant
That probably will improve lag everywhere, I assume? Even if you don't use directly, someone will stop using what you do, to use that?
One thing that I've always had a question about with under sea optical cables is how do the repeater stations get power to do the job? One does not push 6,000 km without them.
Also, what happens when one dies or needs maintenance? Do they pull the cable up to a ship and make repairs? I would think that near impossible do to finding the cable post installation and praying it doesn't snag on something... or some creature building their house over the top of the thing.
Excellent link, but to answer your question, yes the submerged repeaters/amplifiers are powered from the landing stations. In coax cables power went down the centre conductor, in optical fibre cables the repeaters are powered over the copper tube that surrounds the fibres. The power needed is pretty high and can be dangerous, especially if a trawler pulls one up and thinks it is good idea to free their gear (expensive fishing nets) by cutting the cable. They do get cut and, as mentioned in the Wiki, measurements from land can give a good idea of where to send the cable ship, the last repeater responding also gives an indication. The ship grapples the cable and makes repairs on deck.
Additional interesting links are TeleGeography's Submarine Cable FAQ and their Submarine Cable Map (scriptblockers note: needs maps.googleapis.com enabled for the latter).
how do the repeater stations get power to do the job?
Boring: The cable contains an electric wire. Though if I remember correctly, only one; they just create a voltage with the ground at each end. And yeah, they generally pull the cable up, unless they're one of the special submarines used by the NSA to splice in-situ.
Repeaters can also use the energy from a laser
Not really. It's like AmenFromMars says. Onshore there's PFE (Power Feeding Equipment) in the landing stations along the cable*. The PFEs feed a lot of DC into the copper core that's a tube around the fibre core, with some hefty insulation between that and the outer armour wire and sheathing. Then every 150km or so there are the repeaters, aka 'torpedoes' that contain the repeaters that amplify and correct the fibre transmissions to regenerate & boost those for the next hop. The DC power is fed into the active components, then the repeater's jointed to the armour wire, wrapped and lowered back to the seabed.
They're one of the fascinating bits of submarine cable systems. Like the limitation on the number of fibres carried. So a land-based cable would be 144 or 288f, but submarine only 8f, mainly due to the size & weight of the repeaters increases in line with the number of fibres. So more fibres, heavier repeater and then the strain that would put on the cable while it's being laid, or repeared, so a mechanical limit.
*Some systems might have multiple landing stations along it's route, so use branching units to drop out transmissions to those landing stations.
If you only suffer from mild eyerolls at the mid-90s cyberpunk flourishes ("the hacker tourist"), Neal Stephenson's article at Wired (when Wired was still publishing good longform stuffg) is still the best on undersea cables: https://www.wired.com/1996/12/ffglass/
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