Title: Message
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You
are absolutely right!
That's an odd way to look at things.
Your total output in 360 deg coverage area has nothing to do with
dBi. dBi is merely the gain of the antenna.
You don't take your radio power, add the gain of all the antennas that
point in that direction, and somehow spread the total out over all the
receivers in that area. It doesn't work that way.
You may have 360 deg coverage, but you have 2 separate systems, and you
don't get to add them together. In your case, you may have 360 deg
coverage with 2 radios and 2 sectors, but at no point in your coverage area
does either system have more than 12dBi gain at the base station end.
-----Original Message-----
From:
[EMAIL PROTECTED] on behalf of Rudolph Worrell
Sent: Sat 11/1/2003 1:02 PM
To:
[EMAIL PROTECTED]
Cc:
Subject: RE:
[smartBridges] Omni antenna coverage
Certainly you do not get to add the gain
in one radio. When you put the sectors together your
total output in 360 degree coverage area is 24dbi. This is not
combined in anyway it is simply what you get when you look at how many dbi's
you have to cover the area that is intended.
I
have 2 190 degree sectors back to back separated by about 5 ft Horizontally
on a water tower(200ft). One radio on channel 1 and the other on
channel 11. This works great for me and give me a coverage area of up
to 15 miles without an amp. I plan to introduce an amp which will most
likely increase the coverage by about 5 miles or so in open
space.
Possibly, but the assumption is that with 2 sectors, each sector is
on a separate radio. Therefore you don't get to add their gains
together.
As far as the mechanical downtilt on the omni, yes, you can do that,
but why would you want to, unless you are in the unique position of being
on the side of a mountain with people above and below you on the
slope.
-----Original Message-----
From: Rudolph
Worrell [mailto:[EMAIL PROTECTED]
Sent: Fri 10/31/2003
4:48 PM
To: [EMAIL PROTECTED]
Cc:
Subject: RE: [smartBridges] Omni antenna
coverage
Yes! 2 190 degree sector gives you 380 overlapping
coverage. 12dbi on one side and 12dbi on the other = 24dBi
overall.
You can always tilt an antenna to create a down tilt. With
an omni you would lose coverage on the side you tilt away
from.
2 180 deg 12dBi sectors combine to make 24dBi in 360
deg?
Mechanical downtilt on an omni?
Maybe my brain is just fried, but something doesn't add up
here.
I only use Omni's at repeater sites with low number of
clients. I use 190 degree sectors for all serious
connections. 12dbi in 180 or 12dbi in 360. Well I
chose the 12 dbi in 180 each therefore giving me 24 dbi
coverage for 360 degrees.
On your Omnis you should get them with a 3 degree elec
downtilt or use a mechanical downtilt. Electrical is
better!
I too am
running with a 12dbi Omni at about 150â -
customers at about 2-4km get a good signal but the closer you get
the worse the signal gets â I am about to swap out and try a 9dbi
Omni to see if the RF pattern improves for the clients that are
closer. Failing this I will chuck the omniâs and use sectored
antennaâs
Rob
-----Original
Message-----
From:
[EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Ian
Ellison
Sent: 31
October 2003 14:57
To:
[EMAIL PROTECTED]
Subject: Re: [smartBridges]
Omni antenna coverage
I am currently running airPointPro Outdoor
units with Comet GP24-3 Omni's, which is a 12 db antenna. I
am servicing customers as far as 5 miles away with sufficient
results. However, the equipment is about 150' above ground
level which im sure helps. Good
luck.
Ian
Derek Breiland
wrote:
Up to this point I
have been running off of one tower with 3 sectors. I am
looking at putting an addtional AP up about 6 miles from this
tower to penetrate into a community of homes that will otherwise
be difficult to cover due to the number of obstructions not to
mention their elevation on the map leaves a little to be
desired. It will also enable me to install a less expensive
CPE at the customer site if I can bring the AP closer to the
customer making the service a bit of an easier
sell.
I want to utilize an
omni antenna in this area. I have not yet decided what to
backhaul with yet but I am considering an APPO to the new XO2
at the remote. I can use one radio on the XO2 for the
backhaul on one channel and the other radio for the access to the
customers. I am not a big fan of repeaters unless absolutley
necessary. It seems that most complaints on this site have
the word "repeater" in the paragraph so I will try and stay away
from it.
My
question is to anyone currently
working with onmi antennes on an AP. What ranges can I
expect for the various dB omni antennas? 9dB seems small to
me, 12dB is maybe the ticket, 15db - way overkill? I do not
want the pattern to get too large to cause problems with my main
tower. I am looking at trying to get out no more than 3
miles for the AP. The AP and omni will be mounted on a
40'-50' existing tower. Also has anyone had better results
with one manufacturer over the other with the same dB
antenna?
Any suggestions are
greatly appreciated. I will be doing more and more of this
so I would like to get it right the first time based on others
experiences in already doing
it.
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