6 ms·
The velocity factor is around 2/3 in optical fiber. That's slow to HFT firms. For example, the delay compared to vacuum/c would be of of 2ms for a 1000km link.
by Faaak 8y ago
The velocity factor is around 2/3 in optical fiber. That's slow to HFT firms. For example, the delay compared to vacuum/c would be of of 2ms for a 1000km link.
And that does not take into account fiber repeaters or microwave links
- DmenshunlAnlsis 8y agoYou’d basically need a 1000km vacuum chamber to achieve that, which would be insanely expensive and an engineering miracle. I’m not even getting into what you’d be using as a transmission medium, because the vacuum chamber is prohibitive enough.
- ttsda 8y agoYou could use LEO satellites, add a few km up and down but you have way less hardware to pass through.
- DmenshunlAnlsis 8y agoThat’s a good point, the difference between vacuum and atmosphere isn’t so significant, but then it’s not really a new tech or “lightspeed internet” it’s just a satellite link.
- ttsda 8y agoWith the addition of satellite-to-satellite optical connections, which will greatly improve latency and bandwidth.
- DmenshunlAnlsis 8y agoIf SpaceX pulls off their swarm of telecom satellites, we might get to see how it really works in widespread practice. Exciting prospect!
- ttsda 8y agoIndeed. And what I'm most interested in is all the cash they're dumping into commercial phased-array antennas. If they manage to scale enough to get them to a low enough price they will be amazing for all sorts of other stuff.
- petters 8y agoNo, there is hollow fiber for communication. https://gizmodo.com/5992303/hollow-fiber-optic-tunnels-can-blast-data-at-practically-the-speed-of-light https://gizmodo.com/5992303/hollow-fiber-optic-tunnels-can-b...
- DmenshunlAnlsis 8y agobut also reasonably low data loss of 3.5 dB/km. That still adds up at a distance though, so these crazy fast cables are most likely destined for supercomputer and data center applications, for now at least. Not really for communication, and I suspect that if you want it to scale up to 1000km, it’s going to strongly resemble the vacuum chamber I mentioned.
- black_puppydog 8y agoIf they're the only people interested in that, I'm okay with staying at 2/3...
- coldtea 8y ago>That's slow to HFT firms. That's because we allow them to trade at such rates and compete on speed. A mere few decades to half a century ago we have 1/10 to 1/1000 the speed, and trading was going on just fine... I'd opt for a "turn based" trading system (with a small, but not tiny turn window), to eliminate any transmission speedup advantage from different traders.