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SpaceX gets FCC approval to deploy thousands more internet satellites



 
 
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  #11  
Old November 19th 18, 03:31 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,844
Default SpaceX gets FCC approval to deploy thousands more internet satellites

JF Mezei wrote on Mon, 19 Nov 2018
02:49:18 -0500:

On 2018-11-18 21:38, Jeff Findley wrote:

The cargo version of BFS will have a large payload bay .


ok, so there will be a cargo version. Wasn't aware of that. Had only
seen the draw2ings for the cruise shop with hundred+ passengers to Mars.


You are frequently 'not aware' of things. Just how did you think that
"cruise shop [sic]" got to Mars if there was no tanker version to
refuel it in Earth orbit so that it could make the trip?

Actually I'm not sure that's still current information, either.
Original plan was for three versions; a 'passenger' version, a 'cargo'
version, and a tanker version. One of the three went away. I thought
they combined the 'passenger' and 'cargo' versions into a single more
versatile vehicle.


the payload bay door(s) will open and the satellites will be released in
sequence just like Iridium satellites are released from a Falcon 9 upper
stage.


So the payload bay will be fitted with the satellite release mechanism
specific to those stalellites, right? Sort of like the Shuttle payload
being fitted with multiple PAM launchers ?


Which part of "just like a Falcon 9 upper stage" is it that you're
having trouble wrapping your head around?


I don't understand your point. Since it's a global satellite network,
you put the ground terminals exactly where they're needed.


In Canada, unlike the USA, the vast majority of the area where services
are needed do not have any fibre ANYWHERE near, so you can't place the
ground stations where they are needed and need to aggregate traffic to a
satteline that is over a ground station.


Huh? With 7500 or so birds in orbit, a lot of them are going to be
visible at once from any given point, even though they're only 350
miles or so up.


So to serve a town like Resolute Bay at 73 latitude, the satellite that
passes overhead may have to pass the signals down to another and then
another to reach one that is over a ground station. The thing is that
ground station will end up service a verty large area of northern Canada
and thus aggregate a lot fo traffic and this is where the uplink
capacity matters.


Yes, the 7500 orbiting satellites are nodes in a single large network.
What's your point?


These aren't really huge "ground stations".


This issue isn't their size (although you want a huge antenna to paliate
rain/snow fade effect on the uplink since that will affect a lot of users.


Again, huh?

Again, this is a global LEO satellite network. SpaceX could put their
ground stations closest to where the major data sources are in order to
minimize latency and dependence on the existing Internet backbones.


Again, it has to do with spectrum/bandwidth available for the uplink
between one ground station and the staellite currently passing over it
and how many end users end up being connected to that ground station.


With 7500 satellites in the constellation, how many are visible from a
given ground station? Nothing says you have to use the one directly
overhead.


Consider an extreme example of SpaceX having 1 antenna over Musk's home
as the single ground station for the world. All satellites will be
connected and data will flow from the internet to musk's home , on the
uplink to a satellite and then relayed from satellite to satellite until
i reacches the satelite over Gabon where it pushes the data down to the
home of someone in Gabon.

This all works and looks great. The problem is that that one uplink over
Musk's home will be limited in capacity by how much spectrum the ITU/FCC
will have given it and the capacity of the satellite passing over Musk's
house at anty point in time.

If you want to serve the world from 1 ground station, you will need many
many terabits/second capacity on that uplink, and need all your
satellites to be able to process all of the world's data demands since
anyone satellite eventually becomes the one passing over Musk's home and
acts as the main relay to the ground for all of Starlink's end users.


Poppycock! What do you think the bandwidth of the internet backbone
is? Hint: The biggest pipes are around 100 Gbs, over an order of
magnitude smaller than your figure. Most of it is even smaller than
that.


So, it comes down to determining how many ground stations you can have
and how many are needed in order to provide the complete system with
uplink cxapacity that matches the demand from end users.

The more ground stations you have, the more caopaciuty you have and the
better the service end users will have. But the more ground statiosn you
have, the costlier your system becomes. And then you start dealing with
national regulators. Selling service to a Canadian will require the
service abide by CRTC rules, notably net neutrality. But if the groudn
station is in the USA where the Internet no longer exists as a telecom
service, then the "information service" rules (or lack thereof() will
apply.


You still seem confused about how networks work.


Same with a user in Taiwan who might end upo using a ground station
located in China with all of the Chinese firewalls in place.


An end user won't 'use a ground station' unless they're talking to a
business local to that ground station.


Again, you have no idea what Starlink's pricing will be.


If you think it will be radically lower than existing services you are
mistaken. Especially since Musk has stated it needs to generate revenue
to find BFR/BFS, and once they realise how much gorund infrastructure
they will need to support users worldwide, you'll find the costs go way up.


While they haven't established how they're going to charge, they have
said that by the mid-2020's they expect to have 40 million users
generating $30 billion in revenue. That provides a guestimate of what
the 'average' user will pay and it's just not all that high.


The price of the launch is one thing. But if you have demand for X
capaxity, but your system only provides for half of that, then you price
service high and/or impose usage limits or lower speeds to limit demand
for capacity which you don't have. If you oversell the service (as
Xplornet does), then you get a terrible image and people hate you.


Costs and speeds are expected to be commensurate with current wired
internet.

reusability. Starlink will get those launches at cost too. They'll be
far cheaper than launches for any other LEO network.


Getting launches at cost doesn't matter. It's all book keeping. What
matters how how much will be oeration costs, groudn station costs and
how much revenues they will get. (and factor in need to lauhch X
satellites per year to replace falling ones in the longer term)


The satellites are good for around 5.5 years. It costs less than $40
thousand to launch a new one (plus the cost of hardware). I think
you're handwaving problems into existence that don't exist.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
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  #12  
Old November 19th 18, 10:32 PM posted to sci.space.policy
Niklas Holsti
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Posts: 65
Default SpaceX gets FCC approval to deploy thousands more internetsatellites

On 18-11-19 13:53 , Jeff Findley wrote:

Starlink just has to price themselves enough below the existing
providers to steal their customers. ...

...
As for ground station costs, that's why SpaceX is looking to build many
ground stations around the planet. This isn't at all like owning a few
GEO comsats with very few dedicated (uplink) ground stations for each
comsat. This is a network with almost 12,000 satellites talking to
hundreds of ground stations located strategically around the planet to
provide service to millions of customers.


Only "hundreds" of ground stations? I would have guessed at least tens
of thousands of ground stations. Or did you mean to write "hundreds of
thousands"?

Do we know if one Starlink satellite will be able to communicate at the
same time with several ground stations? Perhaps using time-division
multiplexing? I assumed that each satellite would be equivalent to a
cellular-phone tower and would create a Starlink "cell" to serve
multiple ground stations at the same time.

--
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
. @ .
  #13  
Old November 20th 18, 05:07 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,844
Default SpaceX gets FCC approval to deploy thousands more internet satellites

JF Mezei wrote on Mon, 19 Nov 2018
18:40:01 -0500:


Number of ground stations needed is relative to how much capacity the
uplink has, and how many end users will be connecting to the Internet
via that ground station.


That number is essentially zero. 'End users' each have their own
'user terminal' and are leaf nodes on the network.


Once you have too many end-users connecting via
that uplink, you start to have congestion and need to build a second
ground station far enough away to allow re-use of spectrum with
different satellites acting as links to the ground station as they pass
over.


The system will use highly directional phased array antennae for
uplink/downlink. That means you won't see a lot of frequency
contention.


Having multiple satellites connecting to same ground station may not be
as efficient as having only one connecting at a time. Having 1 large
chunk of spectrum allows greater "compression" than splitting that
spectrum in 2 and having 2 separate satellites talk to the ground station.


Doing both will be more efficient. You'd hardly want to bottleneck
all the traffic for Netflix, say, through a single uplink.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #14  
Old November 21st 18, 01:52 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,844
Default SpaceX gets FCC approval to deploy thousands more internet satellites

JF Mezei wrote on Tue, 20 Nov 2018
18:34:08 -0500:

Video showing the updated Starlink config.

https://www.youtube.com/watch?v=QEIUdMiColU

The large constellation is at a 53 inclination so of no use service the
Arctic. (from 550km altitude, footprint not that big).


Note that in the full system there are satellites in polar orbits.


There appears to be a small constallation with polar orbits. Whether
they provide constant converage is not known. (the vodeo doesn't focus
on it as it appear to be a small part of the constellation).


The video doesn't talk about it because the video is largely talking
about 'first phase', which is just the 7500 or so satellites in lower
orbits. Why do you think they would bother to add polar satellites if
they don't provide coverage?


The "sales pitch" appears to be aimed at selling capacity between major
cities (such as between London and Los Angeles) as opposed to
connecting retail customers to the Internet.


What 'sales pitch'? You mean the examples mentioned in the video?


Latency may be low enough at one point in time, but consider the added
lag while links are renegotiated between satellite leaving and satellite
arriving, each with their own links to other satellites.


Latency stays low.


The renegotiation gaps may be acceptable for retail (as they are for
mobile phones when in a car/train), but not sure good enough for commercial.


Why would they be different?


Also, fibre has far more capacity than a laser. Not only can fibre
support simulteneous wavelengths, but there are a lot of strands in a
trans-atlantic cable for instance


Lasers are faster.


It's possible the satellite lasers will have multiple wavelengths, but
not likely to have multiple beams since aim would become difficult
between constantly moving staellites.


Did you watch your own cite? Rates of change are low. The current
design can handle 50% of the entire backhaul load of the current
internet and around 10% of the uplink load from even very dense target
areas.


(the north-south links between sateliotes in same orbital plane would be
stable, but those east-west links between staellites in different
orbital planes would need sophisticated tracking and have varying distances.


It's not THAT sophisticated. Rate of change is slow.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #15  
Old November 22nd 18, 06:38 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,844
Default SpaceX gets FCC approval to deploy thousands more internet satellites

JF Mezei wrote on Wed, 21 Nov 2018
12:32:28 -0500:

On 2018-11-21 08:20, Jeff Findley wrote:

The video isn't a sales pitch, it's made by an expert in the field of
communications. So, you're drawing conclusions about how this will be
sold without actually knowing who SpaceX will be marketing this to.


The expert would be using examples that spaceX gave him, so it does
givce an indication of where SpaceX thinks there is market.


Bull****. Stop pulling things out of your ass. They're EXAMPLES,
which are typically simplified from how the system will actually be
used.


Depends how they do the routing algorithm. A smart software developer
knows that you don't have to run the routing algorithm for every single
packet of data because the satellites move in *very* predictable ways
over time


Since the east-west lasers are directional, it takes time to re-aim the
laser to point to a new satellite that has come into view. north-sour
links are stable, but re-routing to the north south link while you wait
for the lasers to point to new satellite will change latency, and once
contact with new satteelte has been established, a new chage in route
happens.


And they're aimed by arthritic dwarves, so it takes a LONG time to
reaim vice the few milliseconds that any sane system would take.


Also, fibre has far more capacity than a laser. Not only can fibre
support simulteneous wavelengths, but there are a lot of strands in a
trans-atlantic cable for instance


You're talking out of your ass again.


Please pray tell, explain how SpaceX lasers could match/exceed the
lasers used for fibre links. Do they use subspace and go faster thah light ?


Light in fiber is much slower than light in vacuum. It is, in point
of fact, almost a third slower. Now don't you feel stupid for getting
all snarky?


Pray tell how the magical SpaceX laser could provide the capacity that
is given by a cable of say 32 strands, each capable of 4 wavelengths of
100GBPS each.


Show me such a fiber. CABLE BUNDLES of fiber are capable of 100 Gbps
(which is much slower than 100GBPS).

The fact is that Starlink will likely be *faster* than fiber
connections. This means that trading companies will be willing to dump
money into this project so they can reap the benefits (this has been
mentioned in other articles on Starlink because those are your biggest
potential initial customers).


It really depends on how many hops between satellites are needed to go
from A to B. Suspect New York-London may not be competitive because of
adjacency to trans-atlantic cables. But Chicago or Los Angeles to London
might compete, assuming the frequecy route changes in the sky maintain
jitter to a minimum.


You need to stop going with what you 'suspect', because you are almost
inadvertently wrong.



High frequency traders will be beating down the doors of SpaceX to get
in on the ground floor of Starlink for the very reasons Krugman states
in his article above. And they'll have wads of cash in hand.


Until the first thunderstorm over their offices where traders lose
connection for a few minutes and lose millions of dollars.


Uh, RF works fine through thunderstorms. That's why the user
terminals use RF rather than lasers.


There are good reasons "serious" satellite applications want large
dishes. It's called "weather".


Wrong.


Yes, SpaceX needs to promote their plan and PR it to death with all
soprts of fancy promises. But just like BFR/BFS, expect those plans to
be quietly slaled back once the accountants starts to tell Musk the
grandiose plan won't pay for itself.


You're insane.


--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine
  #16  
Old November 22nd 18, 01:44 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 1,786
Default SpaceX gets FCC approval to deploy thousands more internet satellites

In article ,
says...

On 2018-11-21 08:20, Jeff Findley wrote:

The video isn't a sales pitch, it's made by an expert in the field of
communications. So, you're drawing conclusions about how this will be
sold without actually knowing who SpaceX will be marketing this to.


The expert would be using examples that spaceX gave him, so it does
givce an indication of where SpaceX thinks there is market.


Why wouldn't the communications expert just pore over public documents
with technical information like the FCC filings made by SpaceX? Why
would he rely on information from their sales and marketing department?

Depends how they do the routing algorithm. A smart software developer
knows that you don't have to run the routing algorithm for every single
packet of data because the satellites move in *very* predictable ways
over time


Since the east-west lasers are directional, it takes time to re-aim the
laser to point to a new satellite that has come into view. north-sour
links are stable, but re-routing to the north south link while you wait
for the lasers to point to new satellite will change latency, and once
contact with new satteelte has been established, a new chage in route
happens.


Precison mirrors with servos/actuators on them are really damn fast and
if designed correctly can be very precise as well. Ever seen a laser
light show? That's exactly how those lasers are "moved". That's one
solution that SpaceX could use.

At any rate, I'm sure SpaceX engineers have thought of this and have a
solution that's better than what you or I could spitball in a Usenet
News forum. Just because you or I don't know their exact solution
doesn't mean it doesn't exist.

Also, fibre has far more capacity than a laser. Not only can fibre
support simulteneous wavelengths, but there are a lot of strands in a
trans-atlantic cable for instance


You're talking out of your ass again.


Please pray tell, explain how SpaceX lasers could match/exceed the
lasers used for fibre links. Do they use subspace and go faster thah light ?


You're kidding me, right? You did watch the video whose link you
posted, right? The expert gives examples of times. And guess what? He
says Starlink will be faster than fiber. I just threw a wiggle word in
my original statement because high speed communications isn't my field
of expertise.

Pray tell how the magical SpaceX laser could provide the capacity that
is given by a cable of say 32 strands, each capable of 4 wavelengths of
100GBPS each.


Here's a simple problem for you to solve.

Compare the two systems for, say, the distance over the earth's surface
from NYC to Hong Kong. Yes for Starlink you'll have to add in the
distance up to the first satellite and down from the last satellite and
take into account the larger radius from the center of the earth of the
Starlink satellites.

Hint: Don't forget to look up the speed of light in a fiber optic cable
and compare that to the speed of light in vacuum (which is where
Starlink's laser connections will be). If you forget to do this, your
answer will be completely wrong.

The fact is that Starlink will likely be *faster* than fiber
connections. This means that trading companies will be willing to dump
money into this project so they can reap the benefits (this has been
mentioned in other articles on Starlink because those are your biggest
potential initial customers).


It really depends on how many hops between satellites are needed to go
from A to B. Suspect New York-London may not be competitive because of
adjacency to trans-atlantic cables. But Chicago or Los Angeles to London
might compete, assuming the frequecy route changes in the sky maintain
jitter to a minimum.


Again, see the "hint" I gave above.

High frequency traders will be beating down the doors of SpaceX to

get
in on the ground floor of Starlink for the very reasons Krugman states
in his article above. And they'll have wads of cash in hand.


Until the first thunderstorm over their offices where traders lose
connection for a few minutes and lose millions of dollars.


The traders will surely have a backup connection *if* their connection
to Starlink goes down for a short period of time. For users "out in the
sticks" Starlink will still provide better service overall than existing
satellite services.

There are good reasons "serious" satellite applications want large
dishes. It's called "weather".


So you're a high frequency electromagnetic engineer now? Cool!

Phased array antennas aren't new technology. They're all over the
place. So SpaceX isn't blazing any new trails here. They're just
refining existing designs.

Actually nothing proposed for Starlink is new tech. They're just
assembling the various bits of tech into a very large network of
communications satellites.

Kind of like how they did with the tech for Falcon and Dragon. There
was nothing new there. Any other company with the will to do so and the
funding to do so could have done exactly the same.

Yes, SpaceX needs to promote their plan and PR it to death with all
soprts of fancy promises. But just like BFR/BFS, expect those plans to
be quietly slaled back once the accountants starts to tell Musk the
grandiose plan won't pay for itself.


You're damn funny. Even scaling back BFR/BFS it will still do far more
than any launch vehicle in history due to its full reusability and its
ability to refuel the BFS/Starship part.

Hell, even if their reuse plans go horribly awry and SpaceX has to
refurbish the BFS/Starship part once every 5 flights and refurbish the
BFR/Booster part every 10 flights, it would still beat hell out of
anything coming out of NASA, ULA, or Northrup Grumman Innovation Systems
(formerly Orbital ATK). The only real competition SpaceX might have
with BFR/BFS in the next 10 years will be Blue Origin, if they get New
Armstrong flying. And they're still working on getting New Glenn flying
so they've got a ways to go.

And even if BFR/BFS doesn't materialize in the next 10 years, your
comparison is still weak. SpaceX has literally taken the majority of
the global commercial launch market from all of the existing global
players with just Falcon 9 and Falcon Heavy. If SpaceX had to do so,
they could just keep flying Falcons for the next 10 years and still
maintain their position as the leader in low cost launch. Worst case
scenario, they could introduce a Falcon Block 6 if issue crop up with
Block 5.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #17  
Old November 23rd 18, 08:43 PM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 1,786
Default SpaceX gets FCC approval to deploy thousands more internet satellites

In article ,
says...

On 2018-11-22 00:38, Fred J. McCall wrote:

Light in fiber is much slower than light in vacuum. It is, in point
of fact, almost a third slower. Now don't you feel stupid for getting
all snarky?


Yet, whenever it hits a satellite, that light has to be received,
converted to electricity. Not clear if light pulse is routed to the
emittor to the next satellite, or if the satellite needs to receive full
packet before routing it. Every hop introduces latency, and that latency
is greater when you route/switch packets instead of light pulses. So it
bcomes very architecture dependant. (consider care of a light beam from
A to B may contain packets destined to C or D, at whioch point you need
packet switching).


Fiber has the same issues.

And more importantly, while your light may travel faster in vacuum, if
it is a single beam, its capacity would be less and that too introduces
latency as packets need to wait in a queue to get on the light beam.


You're assuming the lasers are the bottleneck. On what basis are you
making this assumption?

McCall doesn't believe 100gbps is common on fibre strands, doesn't
believe that WDM exists to combine multiple separate 100gbps links on a
single strand so hard to discuss when he is so focused on perosnal insults.


And am curious how SpaceX will deal with something called the "SUN". Sun
hitting a sensor on a satellite may blind it from the much weaker laser
signal coming from another satellite. Shades woudl be an obvious
solutions if they can move quickly enough, but may not solve all cases
such as when the sun is low and "parralel" to a laser beam from another
satellite.


Obviously sun shades. And for the rare case where the laser beam is
parallel to the sun's rays, you can route the data around the impacted
satellites instead of through them.

You keep throwing up these hand-waved arguments like no one at SpaceX
has ever thought of these things. The reality is that SpaceX has surely
hired experts in the areas necessary and they don't need to rely on
random people on the Internet posting strawman arguments as to why
Starlink will never work because...

And lastly, Starlink doesn't have to be perfect at first. It just has
to be better than the offerings it is competing against. Primarily that
will be existing satellite offerings that are based on GEO comsats and
whose latency is stupid slow. That's a low bar to clear.

As improvements are made, and newer satellites are launched, the service
will only get better. Designing them to have only a 3 year lifetime
allows for continuous improvement. Continuous improvement is something
all of Musk's companies have done. They're usually quite good at it
too.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #18  
Old November 24th 18, 01:11 AM posted to sci.space.policy
Fred J. McCall[_3_]
external usenet poster
 
Posts: 9,844
Default SpaceX gets FCC approval to deploy thousands more internet satellites

JF Mezei wrote on Fri, 23 Nov 2018
13:49:18 -0500:

On 2018-11-22 00:38, Fred J. McCall wrote:

Light in fiber is much slower than light in vacuum. It is, in point
of fact, almost a third slower. Now don't you feel stupid for getting
all snarky?


Yet, whenever it hits a satellite, that light has to be received,
converted to electricity. Not clear if light pulse is routed to the
emittor to the next satellite, or if the satellite needs to receive full
packet before routing it. Every hop introduces latency, and that latency
is greater when you route/switch packets instead of light pulses. So it
bcomes very architecture dependant. (consider care of a light beam from
A to B may contain packets destined to C or D, at whioch point you need
packet switching).

And more importantly, while your light may travel faster in vacuum, if
it is a single beam, its capacity would be less and that too introduces
latency as packets need to wait in a queue to get on the light beam.


And if you use little gnomes living on each satellite to transcribe
each packet on stone tablets, it will take even longer. Note that
practically all the things you seem to think will slow down a laser
link will also slow down a fiber link, except the speed of light in
fiber is much slower.


McCall doesn't believe 100gbps is common on fibre strands, doesn't
believe that WDM exists to combine multiple separate 100gbps links on a
single strand so hard to discuss when he is so focused on perosnal insults.


Mayfly can't read simple declarative English, so it's hard to discuss
anything when he is so focused on whinging.


And am curious how SpaceX will deal with something called the "SUN". Sun
hitting a sensor on a satellite may blind it from the much weaker laser
signal coming from another satellite. Shades woudl be an obvious
solutions if they can move quickly enough, but may not solve all cases
such as when the sun is low and "parralel" to a laser beam from another
satellite.


I'm not curious at all, since I'm aware that laser light 'looks' very
different from sunlight to a sensor.


Show me such a fiber. CABLE BUNDLES of fiber are capable of 100 Gbps
(which is much slower than 100GBPS).


please use Google. The world has moved a lot since the days of 300 baud
dialup with accoustic couplers. (and google "WDM fibre"


Please support your own claims. That's your job, not mine.

Uh, RF works fine through thunderstorms. That's why the user
terminals use RF rather than lasers.


google
"rain fade" for satellites or even microwave links (this is a major
reason microwave links were not upgraded to modern speeds as rain fade
would require the towers be rebuilt closer to each other).


There are lots of relatively easy ways to deal with this 'problem'. If
there weren't satellite radio and TV would stop working every time it
rained.

Hint: They don't.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #19  
Old November 24th 18, 08:41 AM posted to sci.space.policy
Fred J. McCall[_3_]
external usenet poster
 
Posts: 9,844
Default SpaceX gets FCC approval to deploy thousands more internet satellites

JF Mezei wrote on Fri, 23 Nov 2018
23:28:44 -0500:

On 2018-11-23 14:43, Jeff Findley wrote:

You're assuming the lasers are the bottleneck. On what basis are you
making this assumption?


If satellites A B and C feed data to D who must then forward the data to
E, then the D to E link will be 3 times oversubscribed if the first 3
links are at capacity.


So if the network is badly designed by a moron there will be problems.
Well, DOH! The solution, of course, is to not have a moron design it.


Again, if they have single wavelength in the laser, this is small amount
of capacity by today's standards.


But adequate for 50% of current global internet backhaul capacity. And
you seem to think (or at least be basing your whinging upon) the idea
that Starlink is intended to REPLACE existing fiber. It's not.


You keep throwing up these hand-waved arguments like no one at SpaceX
has ever thought of these things.


And you keep assuming that because Musk tweets stuff while high on
cannabis or other, it must mean that SpaceX has not only thought of
potential problems but also solved them.


And you keep saying moronic things, like the preceding. It's why
you're more a source of laughter than of serious discussion.


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
  #20  
Old November 24th 18, 08:45 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 9,844
Default SpaceX gets FCC approval to deploy thousands more internet satellites

JF Mezei wrote on Fri, 23 Nov 2018
23:32:21 -0500:

On 2018-11-23 19:11, Fred J. McCall wrote:

I'm not curious at all, since I'm aware that laser light 'looks' very
different from sunlight to a sensor.


Which spectrum does a laser use that the sun doesn't emit?


I see you don't understand how lasers work, either. You need to think
about spot power of a monochromatic source.


If both transmit "red" light, then the sensor wont see the alternating
pulses from the other satellite because while the pulse is off, the
sensor will still show 100% red light instead of 0 siunce the sun will
saturate the sensor at 100% whether the other satellite's laser is
pulsed "on" or "off".


Again, if we let someone like you design something stupidly it will
have problems. It's why they don't let people like you design such
things.


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
 




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