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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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Satellite to Satellite communication ?
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Satellite to Satellite communication ?
"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. 2. Is this true for international television programming too ? I know there are live television from Arab countries, Japan etc, in US. Thanks --sony The satellites in question are at an orbit 35,000km above the earth and can 'see' a large portion of the Earth's surface. Two ground stations on separate continents can both see the same satellite if it is correctly located, and so they can pass a call between them. Hence USA-Europe, USA-Asia and so forth is possible in one 'hop'. Satellite to satellite can be done, as in the Iridium system, but I don't know of any other system off-hand which is commercial and made it to service. There's generally not actually a need. Ken |
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Satellite to Satellite communication ?
"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. 2. Is this true for international television programming too ? I know there are live television from Arab countries, Japan etc, in US. Thanks --sony The satellites in question are at an orbit 35,000km above the earth and can 'see' a large portion of the Earth's surface. Two ground stations on separate continents can both see the same satellite if it is correctly located, and so they can pass a call between them. Hence USA-Europe, USA-Asia and so forth is possible in one 'hop'. Satellite to satellite can be done, as in the Iridium system, but I don't know of any other system off-hand which is commercial and made it to service. There's generally not actually a need. Ken |
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Satellite to Satellite communication ?
Norris Watkins wrote:
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 Sometimes there are *multiple* satellite hops, depending. For a one-way broadcast, it doesn't matter much, but a few years ago, I had occasion to watch a Presidential address where multiple televisions were present, and tuned each to a different network. No two were in sync, implying different speed of light delays between the point of origin in Washington D.C., and the local stations. Then there's the noticeable delay on a news program when the anchor is in 'live' contact (espically with videophones) with the reporter in the field.... -- You know what to remove, to reply.... |
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Satellite to Satellite communication ?
Norris Watkins wrote:
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 Sometimes there are *multiple* satellite hops, depending. For a one-way broadcast, it doesn't matter much, but a few years ago, I had occasion to watch a Presidential address where multiple televisions were present, and tuned each to a different network. No two were in sync, implying different speed of light delays between the point of origin in Washington D.C., and the local stations. Then there's the noticeable delay on a news program when the anchor is in 'live' contact (espically with videophones) with the reporter in the field.... -- You know what to remove, to reply.... |
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Satellite to Satellite communication ?
"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. 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 ?
"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. 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 ?
Its called "intersatellite links". Most GEO birds don't have them, but Iridium does.
(Norris Watkins) wrote in message . com... 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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