Satellite to Satellite communication ?

"Marc 182" wrote in message
...
In article , says...
Marc 182 wrote:

Multi-jump communications would create unacceptable delay in a voice
conversation due to the speed of light and the distance to the
satellites. Even a single jump causes a noticeable and annoying delay.
That's why trans-Atlantic/Pacific cables remain popular.

Cables are popular because they're *cheaper* than satellites
(per unit of delivered bandwidth) what with the incredible advances
in fiber optics.

Ok, true enough. But the issue of delay still remains. A single hop
conversation is possible but annoying. A multi-hop conversation would be
impossible to hold in a natural way.

Marc

Not true. It is used in many of the Pacific islands, for one. A single hop,
with minimal extra delays due to compression and processing, is quite
acceptable. Two hops can be a nuisance, but it is actually still quite okay.
It sure beats the heck out of the alternative, which is usually a short-wave
radio-telephone conversation or a telegram!

Ken

Thanks for setting me straight Francois, you are correct


"(null)" wrote in message news:1070919774.530038@smirk...
Stewart Smith wrote:
"Paul F. Dietz" wrote in message
...
Marc 182 wrote:

Multi-jump communications would create unacceptable delay in a voice
conversation due to the speed of light and the distance to the
satellites. Even a single jump causes a noticeable and annoying
delay.
That's why trans-Atlantic/Pacific cables remain popular.

Cables are popular because they're *cheaper* than satellites
(per unit of delivered bandwidth) what with the incredible advances
in fiber optics.

Has anybody ever heard of Echo-Cancelling devices? These can mitigate the
effect of the "bounce" to a great degree. Also, to compensate further,
"Reverb" can be added to flesh out tone and timbre.

Echo cancelling does nothing to reduce time-of-flight issues.
A half-second delay is still a half-second delay.

Adding reverb is contraindicated for telephone communications,
as it tends to reduce intelligibility. Check out speakerphones
for examples thereof. As a matter of fact, there is a fair bit
of research for _reducing_ reverberation in speakerphones.

Signal processing techniques are not useful for fixing problems
due to speed of light causing delays.

300,000 km/second: not just a good idea, it's the law.


Francois.



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Thanks for setting me straight Francois, you are correct


"(null)" wrote in message news:1070919774.530038@smirk...
Stewart Smith wrote:
"Paul F. Dietz" wrote in message
...
Marc 182 wrote:

Multi-jump communications would create unacceptable delay in a voice
conversation due to the speed of light and the distance to the
satellites. Even a single jump causes a noticeable and annoying
delay.
That's why trans-Atlantic/Pacific cables remain popular.

Cables are popular because they're *cheaper* than satellites
(per unit of delivered bandwidth) what with the incredible advances
in fiber optics.

Has anybody ever heard of Echo-Cancelling devices? These can mitigate the
effect of the "bounce" to a great degree. Also, to compensate further,
"Reverb" can be added to flesh out tone and timbre.

Echo cancelling does nothing to reduce time-of-flight issues.
A half-second delay is still a half-second delay.

Adding reverb is contraindicated for telephone communications,
as it tends to reduce intelligibility. Check out speakerphones
for examples thereof. As a matter of fact, there is a fair bit
of research for _reducing_ reverberation in speakerphones.

Signal processing techniques are not useful for fixing problems
due to speed of light causing delays.

300,000 km/second: not just a good idea, it's the law.


Francois.



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.548 / Virus Database: 341 - Release Date: 12/5/03

"Greg D. Moore (Strider)" wrote:

"Norris Watkins" wrote in message
om...
Hello:
1. When you make an international phone call - say from NY to China -
how does the voice data travel ? Does it have to be send to the
satellite and then received at teh ground, some distance away, then
sent to another satellite till it reaches the destination country. ? I
mean is there any direct satellite to satellite communication. Or is
it always bouncing between teh satellite and the ground at an angle.

Generally ground to sat to ground and that's it.

Sat to sat communication is fairly rare.

It's been my imprression that there may be some military sat-to-sat
stuff going on at 60 gigahertz. This band is readily absorbed by oxygen,
making ground intercept of these signals impractical.

(Googling for a minute)

Here's a reference:

http://www.ydi.com/deployinfo/wp-benefits-60ghz.php



--

You know what to remove, to reply....

"Greg D. Moore (Strider)" wrote:

"Norris Watkins" wrote in message
om...
Hello:
1. When you make an international phone call - say from NY to China -
how does the voice data travel ? Does it have to be send to the
satellite and then received at teh ground, some distance away, then
sent to another satellite till it reaches the destination country. ? I
mean is there any direct satellite to satellite communication. Or is
it always bouncing between teh satellite and the ground at an angle.

Generally ground to sat to ground and that's it.

Sat to sat communication is fairly rare.

It's been my imprression that there may be some military sat-to-sat
stuff going on at 60 gigahertz. This band is readily absorbed by oxygen,
making ground intercept of these signals impractical.

(Googling for a minute)

Here's a reference:

http://www.ydi.com/deployinfo/wp-benefits-60ghz.php



--

You know what to remove, to reply....

"Ken Taylor" writes:

Echo cancellation reduces echo, it doesn't do anything to delay except
potentially add to it. Delay doesn't show up as an echo - echo is due to
mismatches; delay is due to propagation delays, processing delays, and
similar time-wasters.


You need a thiotimoline injector to solve the delay issue.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"Ken Taylor" writes:

Echo cancellation reduces echo, it doesn't do anything to delay except
potentially add to it. Delay doesn't show up as an echo - echo is due to
mismatches; delay is due to propagation delays, processing delays, and
similar time-wasters.


You need a thiotimoline injector to solve the delay issue.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

Paul F. Dietz wrote:

Cables are popular because they're *cheaper* than satellites
(per unit of delivered bandwidth) what with the incredible advances
in fiber optics.

Paul



Perhaps for large metropolitan areas. I live in a little podunk place 120
miles from Tucson or Phoenix. Folks on the nearby rez who'd have no way
of getting fiber optic or cable are getting dishes.

However the metropolitan markets are much more lucrative. Don't know if
reaching the planet's rural areas justifies comsats.

--
Hop David
http://clowder.net/hop/index.html

Paul F. Dietz wrote:

Cables are popular because they're *cheaper* than satellites
(per unit of delivered bandwidth) what with the incredible advances
in fiber optics.

Paul



Perhaps for large metropolitan areas. I live in a little podunk place 120
miles from Tucson or Phoenix. Folks on the nearby rez who'd have no way
of getting fiber optic or cable are getting dishes.

However the metropolitan markets are much more lucrative. Don't know if
reaching the planet's rural areas justifies comsats.

--
Hop David
http://clowder.net/hop/index.html

In article 1070919774.530038@smirk, says...
Echo cancelling does nothing to reduce time-of-flight issues.
A half-second delay is still a half-second delay.

A half second is a half second, but canceling the echo does help
intelligibility by removing some noise from the signal. Time-of-flight
isn't the only issue.


Adding reverb is contraindicated for telephone communications,
as it tends to reduce intelligibility. Check out speakerphones
for examples thereof.

Excessive reverb is a bad thing. Done correctly, reverb adds a sense of
presence without interfering with intelligibility.


Signal processing techniques are not useful for fixing problems
due to speed of light causing delays.

True, but these tools are useful for lots of other real-world problems.
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins