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Lasers enable satellite internet backbone, might remove need for deep-sea cables

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Re: Lasers enable satellite internet backbone, might remove need for deep-sea cables

#41
post #33

The key thing here is it allows for very high bandwidth to go almost anywhere on earth, not just spots where it's easy to land a cable. Starlink's already demonstrated how great that is for consumer bandwidth (50Mbps); a multi-gigabit link terminated at a satellite is fantastic. The part that impresses me most is they're talking about LEO satellites. Those move fast! Starlink does this with a very impressive phased a…

> how great that is for consumer bandwidth (50Mbps) 50 Mbps is great consumer bandwidth where?

Almost everywhere in Germany.

Re: Lasers enable satellite internet backbone, might remove need for deep-sea cables

#42
post #32
post #18

Earlier quoted context omitted.

Wouldn't they have to relay between many satellites due to line of sight? And wouldn't that eat up any decrease in time of flight for the signal itself?

I suspect that retransmission with amplification only, without much processing, can be really fast. Modern electronics can routinely do sub-nanosecond latency.

Indeed. If the system is designed with latency in mind, then the receive to send latency can be as low as a few feet of distance equivalent.

Re: Lasers enable satellite internet backbone, might remove need for deep-sea cables

#43

They transmit in near infrared in an environment that is full of particles, wouldn't this cause light pollution in a spectrum many animals would be impacted by? Also, doesn't this have the issue that anything passing through the beam cuts off internet? A bird, a kite, a malicious actor, a dust storm?

There won't be any significant light pollution since the beams are so narrow.

The problem of interference from clouds and precipitation is real, but the problem of physical occlusion probably isn't because the satellites move pretty fast. That would make it hard to persistently block the beam unless you have something as big as a storm cloud.

Re: Lasers enable satellite internet backbone, might remove need for deep-sea cables

#44

https://en.m.wikipedia.org/wiki/Chappe_telegraph Might be cheaper to build an Tower with PV and battery every 30km than running lines. Cell-Tower in remote Locations etc.

Congrats, you've reinvented microwave lines, widely deployed in exactly this manner.

Re: Lasers enable satellite internet backbone, might remove need for deep-sea cables

#45
post #36

Earlier quoted context omitted.

And HFT setups are also nearly colocated with the exchanges I understand -- as close as they can get physically, so adding a hop to space and back may be adding quite a bit of distance.

This would be about reducing latency between these two exchanges to enable arbitrage opportunities the way I understood it.

Exactly. IEX exchange is relatively new, and their big innovation is that they use long spools of fiberoptic wire to delay their user's connections, thus creating an even playing field.

https://www.sec.gov/files/07feb18_hu_iex_becoming_an_exchang...

"The reduction in trading costs (spreads) is broadly consistent with recent theories on how speed advantages may be used to exploit mechanical arbitrage opportunities. These theories suggest that market makers face adverse selection from fast traders even in the absence of traditional “fundamental” informed trading. For instance, Budish et al. (2015) defnes “quote sniping” as the mechanical arbitrage of taking “stale” quotes before market makers can cancel. In his Comment Letter on IEX’s Exchange Application, Eric Budish argues that IEX’s speed bump may be able to mitigate quote sniping as it allows IEX’s pegged orders to avoid executing against market orders at stale prices.7 Moreover, cross-sectional di˙erences in spreads in response to IEX’s protected quote are consistent with recent theory suggesting that exchange speed is a double-edged sword for market makers (Menkveld and Zoican, 2016). On one hand, faster exchanges allow market makers to update their quotes faster, reducing spreads. On the other hand, higher exchange speed results in a higher probability of quote sniping. Hence, the results support this more nuanced view of the net e˙ects of speed on trading costs. "

Re: Lasers enable satellite internet backbone, might remove need for deep-sea cables

#46
post #33

The key thing here is it allows for very high bandwidth to go almost anywhere on earth, not just spots where it's easy to land a cable. Starlink's already demonstrated how great that is for consumer bandwidth (50Mbps); a multi-gigabit link terminated at a satellite is fantastic. The part that impresses me most is they're talking about LEO satellites. Those move fast! Starlink does this with a very impressive phased a…

> how great that is for consumer bandwidth (50Mbps) 50 Mbps is great consumer bandwidth where?

Rural Canada. On a lake shore. 30km from one of Canada's "Top 50" cities.

Where I used to live, I had 2 options for internet access. A Wireless ISP that uses a parabolic antenna pointed at a water-tower about ~20km from my home; or a cell-phone based internet connection.

The WISP allowed me on average 300kb/s transmissions. The Cell-Phone allowed me between 1.5Mb/s and 7Mb/s (to a max use of 5GB/month).

So 50Mb/s is an incredible upgrade.

Re: Lasers enable satellite internet backbone, might remove need for deep-sea cables

#47
post #19

Earlier quoted context omitted.

Sending lasers in a curve should be easy if you use circular polarization. /s You would send to a satellite in view; my orbital dynamics are poor, but I think with the LEO orbits, you may need to relay in space for a cross ocean link, as it seems unlikely one satelite would have a view of both sides. But Telstar 1 and 2 were used for cross-Atlantic microwave relay with a single satellite in view at a time. Future Tel…

How hard can it be

To be clear, Starlink is already doing this. Their satellites have laser links that connect them to each other.

Re: Lasers enable satellite internet backbone, might remove need for deep-sea cables

#48
post #44

https://en.m.wikipedia.org/wiki/Chappe_telegraph Might be cheaper to build an Tower with PV and battery every 30km than running lines. Cell-Tower in remote Locations etc.

Congrats, you've reinvented microwave lines, widely deployed in exactly this manner.

The big difference between open air laser and microwave links is that one of them doesn't require licensed spectrum. The costs of doing it will be much lower.

Re: Lasers enable satellite internet backbone, might remove need for deep-sea cables

#49
post #33

The key thing here is it allows for very high bandwidth to go almost anywhere on earth, not just spots where it's easy to land a cable. Starlink's already demonstrated how great that is for consumer bandwidth (50Mbps); a multi-gigabit link terminated at a satellite is fantastic. The part that impresses me most is they're talking about LEO satellites. Those move fast! Starlink does this with a very impressive phased a…

> how great that is for consumer bandwidth (50Mbps) 50 Mbps is great consumer bandwidth where?

In most places where you can't economically get a fiber. That is, in most places outside dense urban cores. They are petty numerous in the US.
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