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Satellite to Satellite communication ?
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. 2. Is this true for international television programming too ? I know there are live television from Arab countries, Japan etc, in US. Thanks --sony |
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Satellite to Satellite communication ?
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#3
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Satellite to Satellite communication ?
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. Paul |
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Satellite to Satellite communication ?
Paul F. Dietz wrote:
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. Yeah. In general, it's always been true that what could be put on a landline was put on a landline, telecommunications-wise. The old transoceanic cables didn't have the performance to do high bandwidth multichannel voice. Comsats took off as the first good option for transmitting multiple voice channels across oceans. They then caught on doing TV broadcast, though that had been a feature on the first experimental comsat that flew. Both wire cable and fiber optic cables undersea started to compete with comsats and are taking increasing quantities of the market there. They're a lot cheaper now than satellites are, for major concentrations of traffic. And as soon as the fiber optic cables were proved out, the satellite market for transoceanic voice started to die out slowly. But not entirely. There aren't enough cables in a lot of places, and both the cables and the satellites break sometimes, so they end up backing each other up to a large degree. Orbital relay works better for broadcast purposes and for hitting lots of little islands out in an ocean. And always will. -george william herbert |
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Satellite to Satellite communication ?
Paul F. Dietz wrote:
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. Yeah. In general, it's always been true that what could be put on a landline was put on a landline, telecommunications-wise. The old transoceanic cables didn't have the performance to do high bandwidth multichannel voice. Comsats took off as the first good option for transmitting multiple voice channels across oceans. They then caught on doing TV broadcast, though that had been a feature on the first experimental comsat that flew. Both wire cable and fiber optic cables undersea started to compete with comsats and are taking increasing quantities of the market there. They're a lot cheaper now than satellites are, for major concentrations of traffic. And as soon as the fiber optic cables were proved out, the satellite market for transoceanic voice started to die out slowly. But not entirely. There aren't enough cables in a lot of places, and both the cables and the satellites break sometimes, so they end up backing each other up to a large degree. Orbital relay works better for broadcast purposes and for hitting lots of little islands out in an ocean. And always will. -george william herbert |
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Satellite to Satellite communication ?
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. just some info S Smith "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. Paul --- 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 |
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Satellite to Satellite communication ?
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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Satellite to Satellite communication ?
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 |
#10
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Satellite to Satellite communication ?
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 |
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