Title: RE: [smartBridges] Sector antenna range vs omni
Every radio receiver has a minimum internal noise level. Circuit design as well as thermal and electrical noise of the components cause this and that level us usually referred to as the "noise figure" of the receiver. When connected to an antenna the receiver will also receive a variety of atmospheric and man made noises. "Noise floor" refers to the signal level of the noise from any of the above sources. The noise floor can, and often does, vary with time of day, weather conditions, and other radio activity in the area. Does anyone remember how to convert noise figure (usually expressed in db) to signal level (usually expressed in dbm)?
 
In order to receive useful information from a distant transmitter your received signal has to be at some level above the noise floor or noise level. The difference between the noise and the intended signal is called the SNR or Signal to Noise Ratio. Useful radio communication requires enough SNR to discern the information being transmitted from the noise.
 
The Orinoco client manager that comes with their cards will display noise level, signal level and SNR. Smartbridges reports RSSI and Signal quality and I have never figured out how they relate to real world numbers.
 
John
----- Original Message -----
From: phantam
Sent: Saturday, July 19, 2003 12:56 AM
Subject: RE: [smartBridges] Sector antenna range vs omni

Can someone explain the noise floor to me cause the amp's I looked at said something like 3.5db noise floor with 17db receive gain and 30db transmit gain (ye it's a 1 watt amp I know LOL)

Chris

-----Original Message-----
From: Kevin Summers [mailto:[EMAIL PROTECTED]]
Sent: Friday, July 18, 2003 10:08 PM
To: [EMAIL PROTECTED]


No, because when your OMNI sends out a signal it's going in
all directions. A sector takes that signal and focuses it's
strength in the direction you've got it pointing. A sector
antenna will also "hear" better because it's focused on one
area rather than everything coming in from every direction.
The noise floor for a setup with an OMNI is much higher than
that of a sector setup.

Kevin Summers
KISTech Internet Services Inc.
www.kistech.com
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Dennis Burgess
Sent: Friday, July 18, 2003 5:33 PM
To: [EMAIL PROTECTED]
Subject: Re: [smartBridges] Sector antenna range vs omni


Still the question is, does a Omni give you the same range as a sector?

Dennis

----- Original Message -----
From: John
To: [EMAIL PROTECTED]
Sent: Friday, July 18, 2003 5:04 PM
Subject: RE: [smartBridges] Sector antenna range vs omni


sectors do a few things for me. One they allow me to split out my customer
and not over load an AP. secondly they allow me to track people that are war
roaming. Third they allow me to change my tilt to the typography of the
area. and last they mount nicely to the railing of water tanks and sides of
buildings giving me inexpensive towers.

John Mooring
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Jason Keller
Sent: Friday, July 18, 2003 2:24 AM
To: [EMAIL PROTECTED]
Subject: RE: [smartBridges] Sector antenna range vs omni


The sectorized maxrad omni is a joke. Save yourself about 500$ and buy three
of there wisp series sectors and be done with it. You pay an extra $500 for
a fancy mounting apparatus to put them all together. Trust me there is no
difference in the performance, or appearance of the antenna's. Jason

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
On Behalf Of John Hokenson
Sent: Friday, July 18, 2003 1:02 AM
To: [EMAIL PROTECTED]
Subject: Re: [smartBridges] Sector antenna range vs omni

The nice thing about the Maxrad sectorized omni is you can adjust the
patterns to exactly match your coverage area.  Most everyone that I know
that's used them say they out perform the equivalent gain omni by some
degree.

JH
----- Original Message -----
From: phantam
To: '[EMAIL PROTECTED]'
Sent: Thursday, July 17, 2003 10:10 PM
Subject: RE: [smartBridges] Sector antenna range vs omni

Supposedly work decently but in my view there overpriced DRASTICALLY




From: Dennis Burgess [mailto:[EMAIL PROTECTED]]
Sent: Friday, July 18, 2003 12:38 AM
To: [EMAIL PROTECTED]

Assuming a 13 db omni and a 13 dbi sector, and the same power, what is going
to be the better of the two as far as distance.  If there is a diffference,
how much?

Also, I have looked at another omni that is sectorized.  I'm assuming its
one physical unit, with three seperate antennas, and then you add a
splitter, reducing your power.  Do these work decently?

Dennis


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