If you're following along at home, you know that I bought a Belkin F5D6130
access point last week, and lamented that it didn't have a web interface,
especially given that I didn't have the right SNMP config tool to begin
with.  You are also aware that using ap-config 1.3 on the device made it
more secure, added features, and made it so that the Belkin Win32 software
no longer recognised the AP.  *grin*


More testing has yielded some disappointing (but not unexpected) results
of the AP as shipped by Belkin.  For those of you who know where I live, I
do not get signal inside Pegasus Pizza, which is just across the street!
The stock device clearly has crappy antennas, however it takes only two
minutes to have the thing unplugged, opened up, and the stock antennas
removed.  The AP has two relatively standard MCX connectors, one on each
side of the RF-shielded board, which looks small enough to fit into some
sizes of two-outlet electrical boxes (those with a little more internal
room..)

The Belkin has Power over Ethernet, though it doesn't advertise it.  Basic
idea is that since you have two pairs of wire that are unused, you may as
well put power on them and run just one cable to the thing.  You need at
least one cat-5 coupler to add power, and with most APs you need a second
one to remove and feed it to the DC-in jack.  There's no standard for
which pair is used for which contact, so a continuity tester is needed.

It's also important to consider that you are using at most 100mW for an
AP, and probably 30mW for a wireless card.  A tenth of a watt is a pretty
wussy signal, let's face it.  Even high-quality coax has degradation of
the signal, so you want as little of it as practical to avoid nulling out
the benefits of your shiny new high-gain antenna.  Note, though most cards
are 30mW, many of them can be told to run at 100mW with a register tweak.
I know that this can be done for Prism II cards, and which register it is,
since I happen to have one.

The other issue which most people don't have the ability to account for is
SWR, or standing wave ratio.  SWR is a measure of how much of your radio
signal goes out into the airwaves through your antenna, and how much of it
becomes feedback to the transmitter.  1:1 is perfect, and you won't get
anywhere near that.  1.5:1 is considered pretty much as good as it gets
for most mobile applications.  Of course, SWR can be affected by location
of transmitter, antenna, people, trees, the coax cable, phases of the
moon, the number of times a lame commercial appears on TV, etc.  And even
better, feedback from high SWR can fry your transmitter!


Logical progression of thought from the above considerations:

1. You want as little coax as possible, preferably in binary fractions or
   multiples of wavelengths.
2. n feet of cat-5 is less harmful than n feet of coax
3. If you plan to put your antenna on a roof or so, the AP should be up
   there with it.
4. Your AP needs to be in a weatherproof box if it's going to survive 24
   hours in Oregon.
5. Wall warts suck outside, PoE would solve the problem if you keep the
   cat-5 cable under 100ft.
6. Aquiring a UHF SWR meter for the installation would be useful if you
   can get one, though being close enough to read the thing is going to
   affect the SWR.  Do what you can and call it good enough.  Anything
   under 2:1 is good, anything over 3:1 is pretty bad.
7. Anyone going through all of this trouble so they can use wireless
   network connections from the local restaurants is truly pathetic and
   has no life.

-- 
Joseph Carter <[EMAIL PROTECTED]>             You're entitled to my opinion
 
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?

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