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