6 ms·

The race to reconnect Tonga

126 points by jonathan-adly 5y ago

throw0101a 5y ago
Richard Steenbergen regularly gave/gives a presentation called "Everything You Always Wanted to Know About Optical" at NANOG: * https://www.youtube.com/watch?v=nKeZaNwPKPo https://www.youtube.com/watch?v=nKeZaNwPKPo This is fibre optics in general. For long distance stuff (>40km) you want to do a search for "coherent optics". A lot of these long distance fibres have multiple signals going down one glass using different colours ("lambdas") which are (de)muxed; see Dense Wave Division Multiplexing: * https://www.youtube.com/watch?v=dum8UXtbN3o https://www.youtube.com/watch?v=dum8UXtbN3o
bArray 5y ago
> The blackout caused major disruption to aid efforts following the disaster. Speaking to a friend, apparently they currently use expensive international calls to coordinate efforts, limiting them to audio only. In terms of immediate issues, they have been struggling to get enough drinking water to the islands as they usually get it from collection systems on the roofs, which are now contaminated. An internet connection is just one part of the puzzle.
mastazi 5y ago
what is the approximate outer diameter of one of those cables? I'm trying to picture in my head how thick the protective layers are, and how large is the joint box
- abliefern 5y ago
  It's in the article. About the diameter of a garden hose.
aaron695 5y ago
Since last time this article was discussed RE: Starlink > No ground station near by - https://starlink.sx/ https://starlink.sx/ > No lasers online - https://twitter.com/elonmusk/status/1482424984962101249 https://twitter.com/elonmusk/status/1482424984962101249 Starlink is going to put in a ground station - https://au.pcmag.com/networking/92316/spacexs-starlink-working-to-provide-internet-access-in-tonga https://au.pcmag.com/networking/92316/spacexs-starlink-worki... How the cable might break, obviously the pretty small explosion wouldn't break a cable but it might have been the same probable cause of the tsunami, a landslide (which has a lot of energy) - Insights into submarine geohazards from breaks in subsea telecommunication cables - https://doi.org/10.5670/oceanog.2014.40 https://doi.org/10.5670/oceanog.2014.40.
pchristensen 5y ago
If you find this at all interesting, you have to read Neal Stephenson's classic Wired article about undersea cables - https://www.wired.com/1996/12/ffglass/ https://www.wired.com/1996/12/ffglass/
- irrational 5y ago
  Thanks for posting this. What a fascinating read. > one early inventor wanted to use 26-wire cables, one wire for each letter of the alphabet. I’d love to know how he thought that would work. How did he plan on knowing the order of the letters? What about spaces and other punctuation?
  - WJW 5y ago
    The way I'd do it would be to have a big 26-light display, each corresponding to one letter. Then you'd light them up one at a time and have the receiving clerk write down the letters one by one. Efficient? Not very, but I can see how someone without a lot of information theory knowledge (as almost all early inventors would be) would land on that idea first.
    - 1-more 5y ago
      if you squint and kind of wave your hands that's how parallel ports worked, just faster and done by a computer.
    - danrocks 5y ago
      I wonder what the plan was for writing in Chinese...
  - tdeck 5y ago
    There were pre-Morse / Wheatstone telegraph experiments using 26 wires. One notable early system by Salva Campillo used 26+ tubes of electrolyte, one for each letter. Closing the circuit would cause bubbles to form in the tube at the other end. Even wackier systems from before this time used static electricity ("current" electricity was harder to generate in the early days). One proposal was to have a different servant hold a wire for each letter of the alphabet. At the other end a high-voltage Leyden jar would be connected to wires in turn, giving the servant a shock and prompting them to speak their assigned letter. Unfortunately I can't find the source for this one right now (I think it was in the book The Story of Telecommunications).
c54 5y ago
Always impressed by the amount of engineering which goes into the undersea cables and into fiber optic connections in general. One interesting takeaway (at the risk of mentioning an elon company) is that current-gen satellite connectivity will be massively improved by constellations like Starlink, providing a really nice option to disaster zones and places where normal physical connectivity is interrupted. We might even see reduction of dependence on undersea cables in general, which seems good considering the passages on fishing, seafloor disruption, and the whole bit about "uhh yeah sometimes these cables are salvaged..." I am curious about the effects on deep sea marine biology in sensitive areas... most of the ocean floor is desert, but do we have total knowledge about all the places these cables are going through? By fishing activity are we talking about deep sea trawling? The presence of fishing activity implies at least the non-sea-bed areas are in fact not deserted.
- spaetzleesser 5y ago
  I don't think you should be worried about undersea cables. Fishing is the problem.
- elihu 5y ago
  Single mode fiber optic cable has amazingly high bandwidth. It's hard to compete with that with a radio link. (Though I suppose lasers between satellites could in theory be on par with what you can get from a fiber optic link. On the other hand, with fiber you can run bundles of dozens of strands or more, since the fiber is so cheap relative to the cost of everything else that goes into installing an undersea cable.) Relying on a single satellite vendor for telecommunications seems kind of sketchy, but then so is relying on a single cable. I suppose the good news here is that places that currently rely on a single source for their connectivity can use satellite as emergency backup, or use the availability of satellite connectivity as leverage when negotiating with telecoms.
- MauranKilom 5y ago
  I'm surprised how much you seem to worry about ecological impact of deep sea cables... Are there that many? And even if each one were a complete disaster all the way (which seems virtually impossible), it would be... like a one meter strip across the entire ocean that is affected, out of 2500 km? Could you elaborate what impact you are concerned about?

126 points by jonathan-adly 5y ago

Richard Steenbergen regularly gave/gives a presentation called "Everything You Always Wanted to Know About Optical" at NANOG: * https://www.youtube.com/watch?v=nKeZaNwPKPo https://www.youtube.com/watch?v=nKeZaNwPKPo This is fibre optics in general. For long distance stuff (>40km) you want to do a search for "coherent optics". A lot of these long distance fibres have multiple signals going down one glass using different colours ("lambdas") which are (de)muxed; see Dense Wave Division Multiplexing: * https://www.youtube.com/watch?v=dum8UXtbN3o https://www.youtube.com/watch?v=dum8UXtbN3o

bArray 5y ago

> The blackout caused major disruption to aid efforts following the disaster. Speaking to a friend, apparently they currently use expensive international calls to coordinate efforts, limiting them to audio only. In terms of immediate issues, they have been struggling to get enough drinking water to the islands as they usually get it from collection systems on the roofs, which are now contaminated. An internet connection is just one part of the puzzle.

mastazi 5y ago

what is the approximate outer diameter of one of those cables? I'm trying to picture in my head how thick the protective layers are, and how large is the joint box

abliefern 5y ago
It's in the article. About the diameter of a garden hose.

aaron695 5y ago

Since last time this article was discussed RE: Starlink > No ground station near by - https://starlink.sx/ https://starlink.sx/ > No lasers online - https://twitter.com/elonmusk/status/1482424984962101249 https://twitter.com/elonmusk/status/1482424984962101249 Starlink is going to put in a ground station - https://au.pcmag.com/networking/92316/spacexs-starlink-working-to-provide-internet-access-in-tonga https://au.pcmag.com/networking/92316/spacexs-starlink-worki... How the cable might break, obviously the pretty small explosion wouldn't break a cable but it might have been the same probable cause of the tsunami, a landslide (which has a lot of energy) - Insights into submarine geohazards from breaks in subsea telecommunication cables - https://doi.org/10.5670/oceanog.2014.40 https://doi.org/10.5670/oceanog.2014.40.

pchristensen 5y ago

If you find this at all interesting, you have to read Neal Stephenson's classic Wired article about undersea cables - https://www.wired.com/1996/12/ffglass/ https://www.wired.com/1996/12/ffglass/

irrational 5y ago
Thanks for posting this. What a fascinating read. > one early inventor wanted to use 26-wire cables, one wire for each letter of the alphabet. I’d love to know how he thought that would work. How did he plan on knowing the order of the letters? What about spaces and other punctuation?
- WJW 5y ago
  The way I'd do it would be to have a big 26-light display, each corresponding to one letter. Then you'd light them up one at a time and have the receiving clerk write down the letters one by one. Efficient? Not very, but I can see how someone without a lot of information theory knowledge (as almost all early inventors would be) would land on that idea first.
  - 1-more 5y ago
    if you squint and kind of wave your hands that's how parallel ports worked, just faster and done by a computer.
  - danrocks 5y ago
    I wonder what the plan was for writing in Chinese...
- tdeck 5y ago
  There were pre-Morse / Wheatstone telegraph experiments using 26 wires. One notable early system by Salva Campillo used 26+ tubes of electrolyte, one for each letter. Closing the circuit would cause bubbles to form in the tube at the other end. Even wackier systems from before this time used static electricity ("current" electricity was harder to generate in the early days). One proposal was to have a different servant hold a wire for each letter of the alphabet. At the other end a high-voltage Leyden jar would be connected to wires in turn, giving the servant a shock and prompting them to speak their assigned letter. Unfortunately I can't find the source for this one right now (I think it was in the book The Story of Telecommunications).

c54 5y ago

Always impressed by the amount of engineering which goes into the undersea cables and into fiber optic connections in general. One interesting takeaway (at the risk of mentioning an elon company) is that current-gen satellite connectivity will be massively improved by constellations like Starlink, providing a really nice option to disaster zones and places where normal physical connectivity is interrupted. We might even see reduction of dependence on undersea cables in general, which seems good considering the passages on fishing, seafloor disruption, and the whole bit about "uhh yeah sometimes these cables are salvaged..." I am curious about the effects on deep sea marine biology in sensitive areas... most of the ocean floor is desert, but do we have total knowledge about all the places these cables are going through? By fishing activity are we talking about deep sea trawling? The presence of fishing activity implies at least the non-sea-bed areas are in fact not deserted.

spaetzleesser 5y ago
I don't think you should be worried about undersea cables. Fishing is the problem.
elihu 5y ago
Single mode fiber optic cable has amazingly high bandwidth. It's hard to compete with that with a radio link. (Though I suppose lasers between satellites could in theory be on par with what you can get from a fiber optic link. On the other hand, with fiber you can run bundles of dozens of strands or more, since the fiber is so cheap relative to the cost of everything else that goes into installing an undersea cable.) Relying on a single satellite vendor for telecommunications seems kind of sketchy, but then so is relying on a single cable. I suppose the good news here is that places that currently rely on a single source for their connectivity can use satellite as emergency backup, or use the availability of satellite connectivity as leverage when negotiating with telecoms.
MauranKilom 5y ago
I'm surprised how much you seem to worry about ecological impact of deep sea cables... Are there that many? And even if each one were a complete disaster all the way (which seems virtually impossible), it would be... like a one meter strip across the entire ocean that is affected, out of 2500 km? Could you elaborate what impact you are concerned about?