Using lasers to communicate

Eric Davis ericd at shop.internet.net
Sat Feb 17 23:55:38 PST 1996




That URL should be: httpd://www.lasercomm/lasercomm

Eric

P.S. Thanks John for pointing this out!

At 8:42 PM 2/17/96, Eric Davis wrote:
>Woooa there....
>
>Lasers are not exactly expensive or complicated....
>
>Check out www.lasercomm.com. 4-15Mb/s lasers.
>or Cannon 10-100Mb/s lasers.
>
>I have installed these products *many* times and their setup and operation
>is fast and efficient. (used to work for Interop)
>
>Exmaple:
>We used a pair of these, and MBONE, to provide a 2 way real time video
>confrence link joining an IETF session between a room of
>users at Japan Interop (local) and a group in Sweeden (IETF). The setup
>a was last minute point to point Ethernet link from the confrence center
>to a local hotel acress the road. We had 1.5 hours to perform ALL
>of the work, from wiring both roofs, seting up the lasers, wiring
>the internal hotel/confrence center, and setting up systems and projectors.
>!!The Laser setup took about :15 minutes, tops!!
>
>BTW: With this system the transmit "beam" is focused into a "spot" half
>way between the sending and receiving units. The receiving unit
>is tuned to look for that focused "spot". This means that there is a
>very large (area wise) low power laser pattern behind each of the
>receivers! With a sensitive enough receiver, it is possible to hear
>this signal!
>
>When you need to transport a data stream (1-155Mb/s) to a remote
>site, this solution works out to be *MUCH* cheaper than leasing
>circuits from bell, bypass folks, etc..
>
>Another case in point: We (ISN) needed to transport a 100Mb/s (FDDI) between \
>2 sites. Upon checking, the price of PacBell "dim" fiber was outrageous!
>We had no MFS/TCG/etc fiber in the man hole to latch onto. The choice was
>clear.
>
>As for security, the bottom line is that encryption devices are cheap.
>
>Last plus for these units is that most foreign countries do not prevent
>the use of these point to point optical devices. This is not the case
>for spread spectrum multipoint or microwave point to point radio devices.
>
>Eric Davis
>
>
>
>At 10:44 PM 2/17/96, SINCLAIR  DOUGLAS N wrote:
>>> If you have a secure link you don't need encryption.  Arguably, the
>>> converse is true; if you have secure encryption you don't need
>>> a secure link.  Isn't the ability to transmit secure data over
>>> insecure channels one of the primary justifications for encryption?
>>>
>>
>>Of course.  My point, though I seem to have failed to state it,
>>is that encryption is a cheap software thing while laser beams
>>are expensive, complicated, and still not secure.
>
>-------------------------------------------------------------
>Eric Davis -- ericd at internet.net
>Director, Information Systems
>Internet Shopping Network -- http://www.internet.net/
>415-846-7449 Voice -- 415-842-7415 Fax -- KD6HTO Radio
>-------------------------------------------------------------
>- One by one our rights are taken, One by one we loose our
>- freedom. Step by step we're coming for them, One by one
>- we're coming. - Inka Inka - Myth of the Machine - Step Back

-------------------------------------------------------------
Eric Davis -- ericd at internet.net
Director, Information Systems
Internet Shopping Network -- http://www.internet.net/
415-846-7449 Voice -- 415-842-7415 Fax -- KD6HTO Radio
-------------------------------------------------------------
- One by one our rights are taken, One by one we loose our
- freedom. Step by step we're coming for them, One by one
- we're coming. - Inka Inka - Myth of the Machine - Step Back









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