jbjetta
Premium
join:2004-07-23
Laurel, MD
| the good and the bad about this
Actually, I know people who are loosing their jobs over this decision. The idea of the program was to use Ka band which is lower latency then the current satellites using along with more data throughput. Sure latency wouldn't be that great, but still Ka is lower latency frequency.
In the end I am happy they are putting the bandwidth to use by carrying HD channels, now I just hope those on the project can find other jobs at Hughs or somewhere else. |
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techguyga
MCSE, DCSE
Premium
join:2003-12-31
Cumming, GA | The speed of light doesn't change, no matter what frequency it is oscillating. |
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jbjetta
Premium
join:2004-07-23
Laurel, MD
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When did the speed of light make a diffrence to a satallite frequncy? I fail to follow your somewhat skewed perception that optical carriers have anything to do with radio carriers. There are diffrent latency levels for diffrent frenquency bands and distance. Do some research into packet radio before blindly posting. |
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mishaq
Premium
join:2004-01-24
Richardson, TX
clubs: | Radio waves travel at the speed of light... 
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Damn you FCC! |
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jbjetta
Premium
join:2004-07-23
Laurel, MD |
and diffrent frequency bands take different times to travel the same diffrence. So again, now are you comparing the latency of a technology you don't seem to understand? |
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wwdubbia
join:2002-06-03
Clinton, NY
| reply to mishaq
said by mishaq  :Radio waves travel at the speed of light... ...in a vaccuum.
You are also not taking into account terrestial interference, etc. Speed of light is irrelevant in this case, since it's not fiber. |
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techguyga
MCSE, DCSE
Premium
join:2003-12-31
Cumming, GA | There can't be terrestrial interference between the sat and the dish, or it won't work.  Radio waves travel at the speed of light, period, no matter what frequency. |
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doppler
join:2003-03-31
Blue Point, NY | You are beating a dead horse
These are the same guy's who say BPL is good.
Ignoring the fact it doesn't work and pollutes the
radio spectrum (at the speed of light). |
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drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs: | reply to jbjetta
Re: the good and the bad about this
It doesn't matter what frequency band you use to communicate with a satellite. The latency is caused by the distance and is frequency-Independent.
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One man's Magic is another man's Engineering. |
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techguyga
MCSE, DCSE
Premium
join:2003-12-31
Cumming, GA
| reply to doppler
Re: You are beating a dead horse
Actually, I don't know enough about BPL to make a solid judgment. From what I read, most amateur radio operators are opposed because of the pollution BPL creates, but I have seen no scientific evidence to prove either case.
Regardless, any electromagnetic wave (radio included) travels at the speed of light, regardless of frequency. While it is true that the waves will slow when they pass though matter, the slowdown in the case of sat to terra, is negligible. For all intensive purposes, those waves are traveling at the speed of light. |
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AJ5TT
join:2003-08-17
Friendswood, TX
| reply to jbjetta
Re: the good and the bad about this
Ka-band range from 27 GHz to 40 GHz
The Ka-band satellites systems typically employ the 27.5-30.0 GHz SHF frequency range for uplink transmissions (earth-to-space) and the 17.7-20.2 GHz range for downlink transmissions (space-to-earth).
The amount of time it takes for an earth-to-space transmission is the same at any of the above bands (or frequencies). Even lower frequencies such as Ku-band (12 to 18 GHz), C-band (3.4 GHz to 6.7 GHz), L, S, X oe even 144 Mhz takes the same amount of time to travel from the earth to a single point in space which is the speed of light.
If all bands (frequencies) travel at the same rate then the latency must be the distance from the earth to the satellite plus terrestrial systems plus any interference which causes data errors. |
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AJ5TT
join:2003-08-17
Friendswood, TX | reply to jbjetta
I will admit though.. various factors, such as barometric pressure, humidity, molecular content, etc., radio waves travel inside the Earth's atmosphere at a speed slightly less than the speed of light. |
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gogeta6
join:2002-06-20
San Diego, CA
clubs: | reply to jbjetta
Phase velocity can be greater than what we term the speed of light, but group velocity cannot. Any state information is contained in the group velocity. I don't think there is going to be a star trek solution to this any time soon. |
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Hayward
K A R - 1 2 0 C
Premium
join:2000-07-13
Key West, FL
| reply to wwdubbia
said by wwdubbia :Speed of light is irrelevant in this case, since it's not fiber. Last I checked fiber is not a vaccum either... in fact very dense matterial... with splices and relays too.
Even in clear air I'd bet non visible light (like RF) travels faster.
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»haywardm.com (Hayward's Key West) |
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