[IP] more on FCC adopts rules for broadband over power lines

[David Farber <dave@farber.net>]

Begin forwarded message:

From: Brett Glass <brett@lariat.org>
Date: October 16, 2004 5:06:00 PM GMT+01:00
To: Jim Thompson <jim@netgate.com>, dave@farber.net
Cc: Ip <ip@v2.listbox.com>, gerry-faulhaber@mchsi.com
Subject: Re: [IP] more on FCC adopts rules for broadband over power 
lines

At 02:28 AM 10/16/2004, Jim Thompson wrote:

> I heard Mr. Glass speak once at a "open spectrum" conference at 
> Stanford.  He winged about not having sqaters rights in the ISM band,

Not true. I didn't "whinge" (please spell it correctly) about anything;
rather, I called attention to a real problem. And proposed solutions
which would avoid unnecessary interference.

> and he complained about interference to his network right after 
> admitting to operating with large (12-15dBi) omnis attached to his 
> gear.

Omnidirectional antennas (Ours, incidentally, are about 8 dBi) allow the
most spectrally efficient deployments. Multiple directional antennas and
transmitters require the use of more spectrum and therefore increase
interference. In bands where spectrum is scarce and there are few
non-overlapping channels (e.g. 2.4 GHz), points of presence that use
multiple non-overlapping channels preclude frequency coordination among
users of the band. (Interestingly, the proof of this is a practical
application of the "four color mapping theorem.")

> He's getting exactly what he designed for.  Massive interference.

I'm doing better in the presence of interference than any other WISP
in comparable circumstances. However, I cannot provide anywhere near
the reliability of a wired connection. And, yes -- one ordinary cordless
phone in the wrong place could shut down any of my customers.

--Brett Glass

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