Elon musk wins fight with FCC, 15ms satellite internet

2,963 Views | 23 Replies | Last: 4 yr ago by Synopsis
BadBudBam
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https://www.techspot.com/news/79838-spacex-halves-orbiting-height-part-their-satellite-internet.html

15ms latency. sweet. gaming on satellite internet anyone?
Cromagnum
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AG
The math doesn't add up. Current satellite latency is somewhere on the order of 500-1000 ms. Halving the distance isn't going to speed it up nearly 100x.
tamusc
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Cromagnum said:

The math doesn't add up. Current satellite latency is somewhere on the order of 500-1000 ms. Halving the distance isn't going to speed it up nearly 100x.


But aren't current satellite internet satellites in geostationary orbit (around 36,000km altitude)?

Instead of having a few larger satellites in geostationary orbit, Starlink will have nearly 12,000 smaller satellites at various altitudes ranging from 345km up to 1325km.

What SpaceX was halving was the altitude of some of the first wave of satellites from 1100km to 550km, which was requested after initial testing using their two current test satellites.
ABATTBQ11
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AG
Nvmd. I can't do math
LoudestWHOOP!
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AG
Does being below the Van Allen Belt help signal quality?
hph6203
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AG
Cromagnum said:

The math doesn't add up. Current satellite latency is somewhere on the order of 500-1000 ms. Halving the distance isn't going to speed it up nearly 100x.
This is a proposed change to SpaceX's Starlink plan, which has always been a low earth orbit, non-geostationary satellite. Satellites will shift across the sky handing off service, rather than being responsible solely for one service area. SpaceX has only launched two test satellites and they are not operational. The plan is for them to launch ~800 satellites over the next year+ and launch an initial service next year (or likely the year after). Hughes Net, as an example satellite provider, operates it's satellites at 22,000 miles above the earth, so you're right, halving the distance wouldn't drop the latency 100x, but you're not talking about 1150 to 550 km, you're talking 35,000 km to 550 km.
Maximus_Meridius
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AG
Moreover, isn't there an exponent somewhere in the math? I can't really remember, but I was thinking RF signal strength is usually plotted on a logarithmic scale. Been too long since I had my ham license.
tamusc
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AG
Maximus_Meridius said:

Moreover, isn't there an exponent somewhere in the math? I can't really remember, but I was thinking RF signal strength is usually plotted on a logarithmic scale. Been too long since I had my ham license.


The speed of light, which is essentially the speed of RF signals, is the limiting factor. 36,000km versus 550 km makes a big difference when you're talking about a round trip that's measured in milliseconds. There's other factors on the ground communication side, but distance is the biggest variable that current satellite internet providers can't overcome.
aggieforester05
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AG
Maximus_Meridius said:

Moreover, isn't there an exponent somewhere in the math? I can't really remember, but I was thinking RF signal strength is usually plotted on a logarithmic scale. Been too long since I had my ham license.
Signal strength also known as power is measured on a logarithmic scale. The bigger problem for satellite interent is latency, which is the time it takes for the signal to travel both directions and be processed on all ends. The large distance between a satellite and an earth station means high latency. Higher gain antennas and amplifiers can overcome to the power obstacle.
Hagen95
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AG
Seems like a lot of future space debris floating around in the lower atmosphere.
Flashdiaz
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that's kind of what I was thinking, wouldn't there be a bunch of space junk to maneuver around for future space flights?
aggieforester05
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AG
The space junk wouldn't last long before the orbit decays and it falls to earth. I would suspect the LEO satellites have a very short life span due to the required fuel load to stay in LEO. I would still think 1,200 active satellites canvassing the globe would be a lot to manage to avoid collisions and create clear paths for future launches. The atmosphere is a very big place though.
schmendeler
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AG
damn those aliens and their black domain weapons.
hph6203
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AG
It's 12,000 satellites, but these satellites are extremely small relative to the size of the sphere where they will operate (200-1100 lbs). Imagine 12,000 objects not much larger than a 100 gallon drum spread across the entire globe above you and trying not to hit one with a rocket. It'd be harder to hit one than to not hit one. The plan is to have them operate in extremely low earth orbit and at the end of their useful life (5 years?) they will be decommissioned and sent back into the atmosphere to be burned completely up before they hit the ground. The first 75 satellites launched will not burn up completely in the atmosphere, but the amount of material that survives will be minimal, the next batch will be completely destroyed by re-entry.


It complicates rocket launches a little bit more, but I think the payoff of the entire population of the planet having access to high speed internet far outweighs that struggle. Things like "lost at sea" or "lost in the wilderness" will largely be eliminated.
Patentmike
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aggieforester05 said:

Maximus_Meridius said:

Moreover, isn't there an exponent somewhere in the math? I can't really remember, but I was thinking RF signal strength is usually plotted on a logarithmic scale. Been too long since I had my ham license.
Signal strength also known as power is measured on a logarithmic scale. The bigger problem for satellite interent is latency, which is the time it takes for the signal to travel both directions and be processed on all ends. The large distance between a satellite and an earth station means high latency. Higher gain antennas and amplifiers can overcome to the power obstacle.
Two issues--time of flight latency is 1.5% at 550km versus 36,000km.

The other issue is quality of service (QOS). There is a limit on reasonably permissible power output for the earth side transmitter. QOS is will be lower for the same power level at 36,000km vs 550km. If I remember correctly, this means more packets have to be repeated for satellites at higher altitudes. More repeated packets mean increased latency.

Also, depending on how transmission verification is done--latency is not a single trip from transceiver to transceiver, but multiple trips.

PatentMike, J.D.
BS Biochem
MS Molecular Virology


BQwolf05
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AG
How will this impact cell phones. Would this change how it works, as in a switch from cellular to wifi calling? Sorry if stupid question.
benMath08
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AG
I don't have a source but I think the end-user equipment will be pizzabox sized, so no cellphones at least in the first gen.
BQwolf05
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AG
That makes sense. I didn't think about that, i.e. Direct TV equipment. This is why I came to ask the smart people .
ABATTBQ11
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hph6203 said:

It's 12,000 satellites, but these satellites are extremely small relative to the size of the sphere where they will operate (200-1100 lbs). Imagine 12,000 objects not much larger than a 100 gallon drum spread across the entire globe above you and trying not to hit one with a rocket. It'd be harder to hit one than to not hit one. The plan is to have them operate in extremely low earth orbit and at the end of their useful life (5 years?) they will be decommissioned and sent back into the atmosphere to be burned completely up before they hit the ground. The first 75 satellites launched will not burn up completely in the atmosphere, but the amount of material that survives will be minimal, the next batch will be completely destroyed by re-entry.


It complicates rocket launches a little bit more, but I think the payoff of the entire population of the planet having access to high speed internet far outweighs that struggle. Things like "lost at sea" or "lost in the wilderness" will largely be eliminated.


EPIRB's already make getting lost at sea extremely difficult.
agracer
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hph6203 said:

It complicates rocket launches a little bit more, but I think the payoff of the entire population of the planet having access to high speed internet far outweighs that struggle. Things like "lost at sea" or "lost in the wilderness" will largely be eliminated.
In George Orwell`s 1984, citizens were forced by government to be monitored 24/7. Who could predict we`d all sign up voluntarily to be watched and pay for the privledge.
hph6203
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AG
If you're not an idiot and you have one and know how to use it (never used one and understand they're not complicated, but thinking of those lesbian lovers "lost at sea" a couple of years ago), I guess that kind of puts into question the satellite internet as well though.

Edit: Launch is tomorrow at 9:30. The deployment of the satellites should be pretty crazy. Not sure if there will be footage.
Flashdiaz
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AG
we've been giving up privacy in the name of technological convenience.
hph6203
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Launch tonight at 9:30PM CT
hph6203
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The implications of this launch is huge and it went really really well so far. Really excited about what this means.
Synopsis
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Hagen95 said:

Seems like a lot of future space debris floating around in the lower atmosphere.

Leave it up to these guys.
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