[geeks] Free Space Optics

[James]

> Does anyone out there have any experience with free space optics
> products from either Terabeam or Dominion Lasercom?  I'm working on a
> project at $WORK where we are looking at using one of these two vendors
> to connect  two buildings.  The buildings are about 6 small city blocks
> apart, we are looking to get more bandwidth than what our local telco
> can provide for a resonable price.  I don't have much experience with
> eithr of this to companies nor the products they sell.  I'm getting a
> lot conflicting opinions on the two.  I'll take any feedback/opinions
> you have got.  Thanks!


I've worked with Terabeam a few years back. I found it hard to align and
then I got callbacks in the Spring and Fall. The callbacks were due to
(surprise!) thermal expansion. One building was a metal frame steel
building. The building moved enough with the seasonal change to screw up
alignment. As for fog, this part of the country wasn't known for heavy fog
but I suspect it could be an issue.

Do you specifically need the TDM encoding of these products (like to carry
voice channels) or will simple ethernet connectivity work?  If so, you might
consider an RF solution with directional antennas. Very high bandwidth is
possible and you could encrypt traffic if needed.