4 ms·

Yeah I'm pretty sure cables will always beat satellites over the same distance. One interesting idea I heard was to string stationary drones that would relay mi

Yeah I'm pretty sure cables will always beat satellites over the same distance. One interesting idea I heard was to string stationary drones that would relay microwaves across the ocean, similar to what was done with the relay towers between Chicago and New York.

oh_sigh 3y ago
Light travels at ~0.8C through fiber optics, whereas it travels at very close to C through the atmosphere and C in space. You need to make up for the extra ~200 miles going up and down, as well as the extra curvature of the satellites orbital shell vs the ground. But, it is doable, assuming you can relay the signal fast enough from satellite to satellite. Fiber optics needs to also be boosted on long routes, I'm not sure how that affects latency. But at the very least, speed of light up/over/down is faster than .8C for 7000 miles around the earth
- amluto 3y ago
  Getting your fiber to go straight (in the great circle sense) from point A to point B can be quite challenging given the presence of mountains, water, and people or countries that control the land in the way. For what it’s worth, hollow core fiber is available now, although at least the one vendor I found is very very expensive. I haven’t found an entirely clear answer as to the group velocity in hollow core fiber (it’s not in the data sheets), but it ought to be pretty fast. (The group velocity in vacuum-filled waveguide is not the speed of light in a vacuum — it’s slower.)
kolbe 3y ago
Right now, the fastest path from Chicago to London is to bounce radio signals off the ionosphere, which lands them in Lithuania, and then microwave back to London.
- VagueMag 3y ago
  Wow, are there HFT firms doing this? How reliable is it?
  - downvotetruth 3y ago
    Yes; speed is in bits: https://www.wsj.com/amp/articles/high-frequency-traders-eye-satellites-for-ultimate-speed-boost-11617289217 https://www.wsj.com/amp/articles/high-frequency-traders-eye-...
  - Galanwe 3y ago
    No just HFTs use microwave. Most big DC players (e. g. Equinix) provide access to a MW antenna, as well a dedicated links to PBs and exchanges PoP.
    - kolbe 3y ago
      You have outdated information. Mine is correct. If you are talking about the Auora-NJ path, then that's microwaves. I'm talking about Auora-Europe. https://www.linkedin.com/posts/stefanschlamp_cme-eurex-microwave-activity-7027298230296051712-bW6x?utm_source=share&utm_medium=member_ios https://www.linkedin.com/posts/stefanschlamp_cme-eurex-micro...
deleted 3y ago
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oh_sigh 3y ago

Light travels at ~0.8C through fiber optics, whereas it travels at very close to C through the atmosphere and C in space. You need to make up for the extra ~200 miles going up and down, as well as the extra curvature of the satellites orbital shell vs the ground. But, it is doable, assuming you can relay the signal fast enough from satellite to satellite. Fiber optics needs to also be boosted on long routes, I'm not sure how that affects latency. But at the very least, speed of light up/over/down is faster than .8C for 7000 miles around the earth

amluto 3y ago
Getting your fiber to go straight (in the great circle sense) from point A to point B can be quite challenging given the presence of mountains, water, and people or countries that control the land in the way. For what it’s worth, hollow core fiber is available now, although at least the one vendor I found is very very expensive. I haven’t found an entirely clear answer as to the group velocity in hollow core fiber (it’s not in the data sheets), but it ought to be pretty fast. (The group velocity in vacuum-filled waveguide is not the speed of light in a vacuum — it’s slower.)

kolbe 3y ago

Right now, the fastest path from Chicago to London is to bounce radio signals off the ionosphere, which lands them in Lithuania, and then microwave back to London.

VagueMag 3y ago
Wow, are there HFT firms doing this? How reliable is it?
- downvotetruth 3y ago
  Yes; speed is in bits: https://www.wsj.com/amp/articles/high-frequency-traders-eye-satellites-for-ultimate-speed-boost-11617289217 https://www.wsj.com/amp/articles/high-frequency-traders-eye-...
- Galanwe 3y ago
  No just HFTs use microwave. Most big DC players (e. g. Equinix) provide access to a MW antenna, as well a dedicated links to PBs and exchanges PoP.
  - kolbe 3y ago
    You have outdated information. Mine is correct. If you are talking about the Auora-NJ path, then that's microwaves. I'm talking about Auora-Europe. https://www.linkedin.com/posts/stefanschlamp_cme-eurex-microwave-activity-7027298230296051712-bW6x?utm_source=share&utm_medium=member_ios https://www.linkedin.com/posts/stefanschlamp_cme-eurex-micro...

deleted 3y ago

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