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Anonymous_
Anonymous
Premium
join:2004-06-21
127.0.0.1
kudos:2

wireless

fiber?


fAcEtIOUs
Premium
join:2002-03-03
kudos:4

2 edits

said by Anonymous_:

fiber?
No. It is OTA laser communication. No fiber involved.

Distance is limited due to atmospheric conditions and need to maintain eye safety stds.

Things that limit usable distance:
However, for terrestrial applications, the principal limiting factors are:

* Beam dispersion
* Atmospheric absorption
* Rain (lower attenuation)
* Fog (10..~100 dB/km attenuation)
* Snow (lower attenuation)
* Scintillation (lower attenuation) although to a lesser degree in LED Systems
* Background light
* Shadowing
* Pointing stability in wind
* Pollution / smog
* If the sun goes exactly behind the transmitter, it can swamp the signal.

Atmospheric and fog attenuation, which are exponential in nature, limit practical range of FSO devices to several kilometres.

And must meet eye safety stds:
Class 1 & 1M

CLASS 1 LASER PRODUCT
A class 1 laser is safe under all conditions of normal use. This means the maximum permissible exposure (MPE) cannot be exceeded. This class includes high-power lasers within an enclosure that prevents exposure to the radiation and that cannot be opened without shutting down the laser. For example, a continuous laser at 600 nm can emit up to 0.39 mW, but for shorter wavelengths, the maximum emission is lower because of the potential of those wavelengths to generate photochemical damage. The maximum emission is also related to the pulse duration in the case of pulsed lasers and the degree of spatial coherence.

Class 1M
A Class 1M laser is safe for all conditions of use except when passed through magnifying optics such as microscopes and telescopes. Class 1M lasers produce large-diameter beams, or beams that are divergent. The MPE for a Class 1M laser cannot normally be exceeded unless focusing or imaging optics are used to narrow the beam. If the beam is refocused, the hazard of Class 1M lasers may be increased and the product class may be changed. A laser can be classified as Class 1M if the total output power is below class 3B but the power that can pass through the pupil of the eye is within Class 1.


en102
Canadian, eh?

join:2001-01-26
Valencia, CA

Mosquitos, birds, and just about anything else that comes between the 2 sites would cause disruption (i.e. as noted smog in southern Calfornia may cause diffraction).

This would be ok to use between lets say a space station and the moon if distance isn't a limitation. Lining it up at those distances would be an issue though.
--
Canada = Hollywood North



Mike
Premium,Mod
join:2000-09-17
Pittsburgh, PA

Oh sweet. A long range bug zapper / porn downloader.

Always wanted one.



chucky5150
Divers do it Deeper

join:2001-11-03
New Iberia, LA

reply to en102

Re: wireless

While watching some show on the Science channel they did in fact send a laser beam from a satellite to earth and were able to transmit information. However, I don't recall what the speeds where.
--
Member of the US Air Force since May 7th, 2002 To March 29th, 2005

"You sneak up behind yourself and remove your pants before you realize what's going on." KOL

cbiggers

join:2000-08-10
San Luis Obispo, CA

reply to fAcEtIOUs
That list of bullets looks strikingly familiar to Wikipedia...



fAcEtIOUs
Premium
join:2002-03-03
kudos:4

reply to Mike

said by Mike:

Oh sweet. A long range bug zapper / porn downloader.

Always wanted one.
That reminds me of the film "Real Genius" where a laser fills a house with popcorn when the laser hits a big popcorn ball at the end of the movie.

»www.youtube.com/watch?v=S2rtmoSuoL4

Watch 30 secs to 90 secs in to the video.
--
My BLOG .. .. Internet News .. .. My Web Page
Ask yourself one question: 'Do I feel lucky?' Well, do ya punk?


Radio Active
My pappy's a pistol
Premium
join:2003-01-31
Fullerton, CA

said by fAcEtIOUs:

said by Mike:

Oh sweet. A long range bug zapper / porn downloader.

Always wanted one.
That reminds me of the film "Real Genius" where a laser fills a house with popcorn when the laser hits a big popcorn ball at the end of the movie.

(youtube clip)
30 secs to 90 secs in to the video.
"ICE IS NICE!!!"
--
Civil disobedience is still disobedience.


digitalfreak
Premium
join:2005-12-09
Blacklick, OH

1 edit

reply to fAcEtIOUs

said by fAcEtIOUs:

said by Mike:

Oh sweet. A long range bug zapper / porn downloader.

Always wanted one.
That reminds me of the film "Real Genius" where a laser fills a house with popcorn when the laser hits a big popcorn ball at the end of the movie.

(youtube clip)
30 secs to 90 secs in to the video.
LOL You realize you just posted a link to an illegal file on the internet? I guess all that anti-piracy and copyright infringement rhetoric you spew around here only applies to everyone else.


totalaccess
Premium
join:2002-10-04
Austin, TX

reply to Anonymous_
nope - laser. 1.2 terabytes a second.



meh37

@verizon.net

1.2 terabits per second (that's "tera" as in metric/decimal--data comm speeds are measured/represented in decimal/metric and not binary, so orders of 1,000 not 1024, because bits are simply being counted and not being represented as some amount of "storage")

That's 1.2 trillion bits per second.


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