The signal is probably marginal, but usable except for hot weather. When
operating, the percentage of missed pings is 0.05 percent (5 in 10,000). The
percentage of dropped received packets is typically 20% at the ridge top,
rural WAP11. The percentage of dropped received packets clusters around 80%
during the day for the city WAP11. This drops to 40% from 10 PM to 7 AM
while the city sleeps. This compares unfavorably to a 1.5 mile rural WAP11
link where dropped received packets are below 1%. The 5 mile link power
budget suggests a 25 db margin if only free space propagation is considered.
By rotating the antenna left or right until the link drops and estimating
the angle, and comparing this to the antenna pattern, if seems the real link
fade margin is between 5 and 10 db. The city end of the link seems to have
trouble picking up the ridgetop signal from the local urban background
noise. I believe the FCC regs would permit an 8 db boost from the WAP11's 16
dbm output (Linksys quotes 18 dbm output but this includes 2 db from the
dipole).

Does anyone have a suggestion for a standalone 802.11b access point with a
250 milliwatt output in the USD 200 - 300 price range?

Thank you for the help.
Loren Zemenick

-----Original Message-----
From: S Woodside [mailto:[EMAIL PROTECTED]
Sent: Tuesday, June 17, 2003 10:46 PM
To: Loren Zemenick
Cc: Wireless
Subject: Re: [BAWUG] Why might a 5 mile link degrade during hot weather?


Well, if you want to talk about trees, they do tend to release a lot of
moisture into the air on a hot day, IIRC. I don't think they actually
have more water in the tree though.

Is there some way to tell if your signal is already marginal at normal
times?

Simon

On Tuesday, June 17, 2003, at 03:37  PM, Loren Zemenick wrote:

> Grasping for theories, I have stretched so far as to postulate that
> trees in
> the Fresnel zone have a higher water content when actively
> photosynthesizing
> under bright sun and with hot air temperatures. This extra water drops
> the
> signal strength on a marginal link into non-operation.
>

--
www.simonwoodside.com -- 99% Devil, 1% Angel

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