[TriLUG] How to connect two buildings a mile apart...

[William W. Ward]

Guys -

I spoke to an ex-Harris engineer about this.  He pointed out some of the
commercially installed Harris gear that he'd worked on and indicated that
anything above 1.5mbit in that class of hardware would require professional
installation and FCC licensing, but the costs would be about $25,000 for DS3
(45mbit) or better.

He did acknowledge that 802.11b (2.4Ghz) at 1 watt with a parabolic antenna
and some gain would easily span 1 mile and be rain resistant.  He figured
that you might have problems if you lived in Florida, but typically rain
here wasn't bad enough to knock down the signal.  Further, you can employ a
diversity antenna arrangement, by stacking two antennas together and
connecting one to each receiver of your AP on both ends.  Most APs support
diversity.

Bottom line - you should be able to achieve acceptable levels of reliability
with an off-the-shelf 802.11b system, but if you want mission-critical
reliability, you'll need to pay for a professional solution.  I don't see
why it wouldn't be feasible to load balance across TWO independent 802.11b
links, perhaps one at one corner of each building.  Who knows, for the
money, I don't see why it would be a big deal to try.  Just don't expect the
Linksys you buy at Compusa to deliver the wattage you need, it seems that
all the low-end hardware stops at 500 milliwatts.

Trees are a concern if you have them.

-b-



----- Original Message -----
From: "John Franklin" <franklin at elfie.org>
To: <trilug at trilug.org>
Sent: Wednesday, July 31, 2002 1:32 PM
Subject: Re: [TriLUG] How to connect two buildings a mile apart...



On Wednesday, July 31, 2002, at 01:01  PM, William W. Ward wrote:
> Its a one-time expense, as long as the hardware lasts, so you can
> depreciate
> the expense over time.
> The only other possibility that I'd be interested in is dropping fiber
> for
> that mile-span, but I beleive a mile's worth of fiber is >$3,000 before
> you
> discuss how to get it in the ground and terminated.

I'd go with the fiber drop.  Here's why:

* Fiber isn't subject to arboreal or avian DOS.
* Fiber is more secure than 802.11.
* Fiber can carry considerably more bandwidth than current wireless
solutions (excepting possibly microwave - I don't know how much data
microwave can carry)
* Fiber can be leased and therefore maintained by someone else.
* Fiber takes less power than microwave

In its defense, microwave, depending on the power level, doesn't suffer
from avian DOS.  Rather the reverse.

jf
--
John Franklin
franklin at elfie.org
ICBM: 35°43'56"N 78°53'27"W

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