Cohousing-L Mailing List: Re: COHOUSING-L digest 130

[Scott Cowley (scowley]

Paul,
Here is what I (think I) know about a datacom system for a cohousing community:

- Put in ducts during construction to avoid dirt disruption later.
  Also, thread a 1/4" polypropylene twine through it as the sections of PVC 
duct 
  are being glued together.
- Use a LAN "star" layout emanating from the common house mechanical room.
- You can start with "category 5" twisted pair copper wire which promises to
support fairly high data rates for a while, with lower-priced transceivers at 
the ends.  Or you could put in fiber optic mains and go to copper at the homes,
or you could go fiber optic all the way to the P.C.s at the desk!
-  In the case of fiber optic, The more fibers the better.
- a 64-fiber optic cable is about 1.25 inches in diameter.  A 36-fiber cable is 
about .75 inch in diamter.  Two wires (for a home) total about .25 inch in 
diameter.
- Optical fiber cable requires a bending radius, on turns, of 15 times the 
diameter.
- "Multi-mode" optical fiber is o.k. for 300 yard runs.  It is cheap (84 
cents/ft) and can also be directly buried (not advisable).  "Single Mode" is
better, but more expensive.
- A new "Gigabit" Ethernet standard is out which will require optical fiber.
  Only one hub (switch)  can be put in such a run.
  Also pretty intriguing is the ATM protocol.  See "Telecommunications", 
  March 1997, pg. 31, for a discussion of both.
- Optical fiber signals can be changed to "10BaseT" (twisted pair), category 5
wire signals with transceivers (modems).  These cost about $275 per end, but 
are 
falling in price.
- Optical fiber is not hard to install.  It can be pulled with a piece of 1/4"
polypropylene twine, or actually blown in with compressed air.  Testing it is
also pretty easy.
  To splice it, however, requires special equipment, but is easily do-able.
- THE local TV Cable company is claiming to be able to provide digital internet
service by the end of this year.
- Also on the horizon (2000) is digital communication via satellites.  Gates 
and 
a cable guy have ganged up to monopolize this, too (-opinion).
- Optical fiber has the capacity to support video links, as well as an audio 
link, and a data link using existing special modems.   However, all this 
requires more money at the ends.
- I don't know much about multi-platform o.s.s, but I know that even the older
(used) versions of Novell  (2.15, 3.1) supported apples.  Also check out
Novell Lite and Lantastic.
- Here's a couple of good URLs, one for cable, one for a modem company:
    http://www.occfiber.com/bselect.html
    http://www.pacificnet.net/fiberoptics/
-the newsgroup, "science.optics.fiber" seems to be a pretty good resource.
- A server doesn't require a lot of cpu speed.  You could probably put together
one for under $800.  Then just add disk space and better ethernet cards or 
modems.