Well I'm pretty sure these signal boosters for cell phones are a scam.
But the idea behind them is that the people designing the antennas for
your cell phone made some error in the radiation pattern. That is they
thought you'd hold the phone at 30 deg and the tower would be at 10 deg
when you're 300 ft or more away, but in fact it's at 5 deg and you hold
your phone at 33.4 degrees and so the radiation pattern should be
more more focused in that area. But these chips don't have the advantage
of being direct radiators and it's questionable their assumptions are
any better than the cell phone manufacturers.

In our case however you can extend the range 50-200% by selecting the
right antenna. You can even calculate exactly how much stronger your
signal will be with the dBi numbers. You're best bet is to draw the area
in question and see how much of the area will be in the 3dB cone, how
much in 6dB etc. Then draw radiating circles for atmospheric loss. You
can do this for various antennas and figure out how to cover the
greatest useful area with the whatever signal strength and noise floor
you have. You can safely assume that with standard PRISM2 card there
should be a 20dB margin, for ORiNOCO 12dB, and Cisco 9dB. You can
connect with less, but these will give you a good dependable connection.
You can look at what kind of margin you get with your AP's built in
antennas, and assume it gives you a 2-3 dBi gain. Use iwconfig in
Linux; I think Netstumber gives the numbers in Windows. I think
typicaly you start out with a 30dB margin, but I've seen the margin at
60dB with a 100mW AP with a 21dB antenna. It depends on ambient noise in
addition to the quality of the equipment. I can't vouch for how accurate
those readings are either, some cards seem more dependable than others.
I think the popular ORiNOCO card gives good numbers though.

Superpass probably has the greatest variety of antennas at low cost that
you can order directly. Look through the nycwireless archives for other
antenna makers as well. There is someone else with the cheapest omni's
and dbiplus(poynting) has some cheap yagi's if you buy in bulk.

-- Daniel

On Thu, 19 Sep 2002, Jon Baer wrote:

]Does anyone know if items like this:
]
]http://www.thesignalbooster.com/
]
]Would work for 80211?
]
]- Jon
]
]--
]NYCwireless - http://www.nycwireless.net/
]Un/Subscribe: http://lists.nycwireless.net/mailman/listinfo/nycwireless/
]Archives: http://lists.nycwireless.net/pipermail/nycwireless/
]

-- 

  <<You cant eat before a operashun. Not even cheese.>> -- Charlie Gordon

--
NYCwireless - http://www.nycwireless.net/
Un/Subscribe: http://lists.nycwireless.net/mailman/listinfo/nycwireless/
Archives: http://lists.nycwireless.net/pipermail/nycwireless/

Reply via email to