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The First Detailed Look at How Elon Musk's Space Internet Could Work (newscientist.com)
SpaceX has been granted permission by the Federal Communications Commission (FCC) to set up a vast network of thousands of low Earth orbit communication satellites. But the company has been tight-lipped about the project, known as Starlink. Mark Handley, University College London built a simulator based on public details from the FCC filings to understand the latency properties of the network. New Scientist reports: Although Musk has said he wants more than half of all internet traffic to go through Starlink -- Handley's simulation suggests that the project will be most appealing to high-frequency traders at big banks, who might be willing to fork out large sums for dedicated, faster connections. To create the simulation, Handley took what information he could from SpaceX's public FCC filings and combined this with his knowledge of computer networks. Initially, Starlink will consist of 4425 satellites orbiting between 1100 and 1300 kilometres up, a greater number of active satellites than are currently in orbit. There is only one way to arrange this many in a configuration that minimises collisions, says Handley. So he is confident that his simulation reflects what SpaceX is going for.
When sending an internet message via Starlink, a ground station will begin by using radio waves to talk to a satellite above it. Once in space, the message will be fired from satellite to satellite using lasers until it is above its destination. From there, it will be beamed down to the right ground station using radio waves again. Between distant places, this will allow messages to be sent about twice as fast as through the optical fibres on Earth that currently connect the internet, despite having to travel to space and back. This is because the speed of the signal in glass is slower than it is through space.
When sending an internet message via Starlink, a ground station will begin by using radio waves to talk to a satellite above it. Once in space, the message will be fired from satellite to satellite using lasers until it is above its destination. From there, it will be beamed down to the right ground station using radio waves again. Between distant places, this will allow messages to be sent about twice as fast as through the optical fibres on Earth that currently connect the internet, despite having to travel to space and back. This is because the speed of the signal in glass is slower than it is through space.
The downside to shortwave is the relatively low amount of available bandwidth. It works for high frequency trading because the amount of data transferred is very small. Another problem is that shortwave is subject to so much atmospheric and solar disturbances. I am a licensed Amateur Extra and I know the fun of sometimes getting long distance contacts and sometimes not.
Problem is, fiber on the ground is faster as the distance is shorter.
Only true in general for relatively short trips with fixed destinations.
Unless you live in some remote place that depends on geo-stationary satellites for internet, you are better off going along the ground, at least where latency is concerned.
A) These are not geo-stationary satellites SpaceX is proposing. Geostationary orbit is about 35,700km away versus the 1200km being proposed here. That difference is very significant. B) Ground is only faster in some use cases but not all and the longer the transmission the less advantage it has.
Rule of thumb: light does:
* 1 m / 3 ns - signal in vacuum
* 1 m / 4 ns - signal in copper wire
* 1 m / 5 ns - signal in fiber optic cable
It's a lot slower in in a bent fiber optic cable, of course, but long runs are effectively straight.
Socialism: a lie told by totalitarians and believed by fools.