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Data transmission with infrared lasers

Get connected to thy neighbour
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You live a couple of blocks away from your friend, and any of your internet connections is too limited for high-bandwidth applications? Cable not feasible? Too far away for wireless? Infrared lasers to the rescue!

Why not use a point on a building which you BOTH see from your respective apartments as a mirror on which to beam your infrared lasers, as to communicate data back and forth, thus setting up your Infrared Laser Network (InLaN) Connection Kit?

But wait, there's more! The kit comes complete with an InLaN Relay as well, in case you need to beam off multiple buildings -- remember, with an InLaN Relay you can effectively beam across as much as THREE buildings! Experts agree that you can find ways to connect two apartments as far as two miles apart in more than 90% of cases using our exclusive InLaN Kit! Buy Now!

gutza, Sep 14 2006

Laser Data Link http://www.laserbandwidth.com/
first link I could find on google out of 22,000,000 for search "laser data link" [webfishrune, Sep 14 2006]

[link]






       baked, baked, baked!   

       for years - i.e. before 802.11 wireless and stuff. You can buy the modules from most electronics suppliers.   

       [-] for no research
webfishrune, Sep 14 2006
  

       If you have line of sight, use parabolic dishes behind 802.11 antennas. Inexpensive and it'll still work in rain or snow (signal strength will be reduced less then that of a laser). Can also be bounced off a concrete building.
jmvw, Sep 14 2006
  

       //Can also be bounced off a concrete building.//   

       True, but I would not base the integrity of a link on reflection by design!
webfishrune, Sep 14 2006
  

       Very very baked. The indirect reflection thing is less baked, though, and is kind of interesting.   

       One of the original modes for 802.11, besides the radio modes that eveyone actually uses now, was an indirect infrared mode. The idea was that the "base station" would point upwards and bounce a diffuse signal off the office ceiling, getting it over cubicle walls. I have no idea whether there was ever a product that worked this way, but it is in the 802.11 spec.
wiml, Sep 14 2006
  

       webfishrune, you're too harsh--I never said anything about a direct connection, i.e. it is assumed that you do NOT have line of sight.   

       But then again, I stand corrected: I didn't know about the 802.11 specification which apparently is quite similar to my "proposal".
gutza, Sep 14 2006
  

       So the broadcaster shines a laser spot on a building and the reveiver points a telescope with IR optics at the same spot?   

       Interessting. I wonder what legal recourse the building owner would have to stop you doing it.
st3f, Sep 14 2006
  

       [Ian], no, I'm pretty sure it requires the clients to talk back (ACKs if nothing else), so the clients would need to have a ood shot at the ceiling too. Or something. The specification does not seem to take Jean Michel Jarre into consideration, unfortunately.   

       I think it's odd that there aren't other diffuse-IR devices out there, actually. It seems like a useful technique.   

       [st3f], I'm guessing the building owner would have the same recourse as they would if I were receiving a radio signal that had gone through their building, i.e. none.
wiml, Sep 15 2006
  

       [wiml], I don't see consumers calibrating all stations to point to a precise location on the ceiling in order to send meaningful responses. I might be wrong, of course, but I really don't see this working in a busy office, with people stumbling on most desks all day long.
gutza, Sep 15 2006
  

       They wouldn't need to point at a precise location --- it's diffuse. That is, each station has a bright emitter that lights up a big patch of ceiling (the spec lists power levels up to 2 Watts), and a detector that likewise sees a big patch of ceiling. As long as there's overlap between the sender's patch and the receiver's patch, it ought to work.   

       (Still, I'm not too surprised that the 2.4GHz PHY took over instead of the infrared PHY.)
wiml, Sep 16 2006
  
      
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