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which polarization would you use?

Posted: Thu Jun 29, 2006 10:33 am
by franco
which polarization would you use?
Horizontal or verikal?
It is a control tower with sector aerials.

Posted: Thu Jun 29, 2006 1:23 pm
by phil@nowires.com.au
Hi Franco,

I'd have a scan about and see what polarisation any interference is on, and use the opposite.

For my network, I use vertical, as most laptop's builtin antennas are vertical.

Regards...ƒil

Posted: Thu Jun 29, 2006 3:42 pm
by kenk
We use Horizontal - as unlike Phil, all our Kangaroos are vertical, while his
are asleep. :lol:

We get better results from our 2.4 horizontal sectors in terms of range and NLOS services. Trees buildings people streetlamps are all vertical.
The horizontal polarisation seems to work better over the beach also.
We used vertical omnis in the past, but now use horizontal sectors where
possible on 2.4

On 5.8 we use opposite polarisations on back to back links, but as Phil
said check the noise floor and adjacent frequencies before making a
choice.

I think the pattern from laptop aerials are doughnut shaped, and the
cross polarisation doesnt seem to worry them too much.

Posted: Thu Jun 29, 2006 8:57 pm
by GotNet
I'll second Kenk. So much bounce going to a laptop. Having the lowest noise at the AP to hear the weak return is the trick.

Never tried a RF Kangaroo. :)

Posted: Fri Jun 30, 2006 6:14 am
by franco
I'd have a scan about and see what polarisation any interference is on, and use the opposite.
How I can do this?

Posted: Sat Aug 26, 2006 9:04 pm
by tkmbe
I don't know if it is true but I have found some time ago while I was investigating this question
the following statement:

Vertical polarization is better for long distance links because
ground attenuate signal in horizontal polarization in long range!

Beat

Re: which polarization would you use?

Posted: Sun Aug 27, 2006 7:01 am
by aitsecurity
which polarization would you use?
Horizontal or verikal?
It is a control tower with sector aerials.
look this test in real world, for little link of 2.810 meters

the Point A to 200 meters have a towers of power lines Big towers, and the zone fresnel is no perfect.

in point A have a 26 dBm AP, with 24 dBi grid antenna

in point B have a 17.5 dBi CPE with 24 dBi antenna

with horizontal or vertical have the same RSSI the same dBm in both points A and B


but, in horizontal, the perfomance speed is 2mbps, with vertical go up to 3.5 mbps



remember the tower of power lines in 250 meters of point A, this tower is vertical, this is the problem when use horizontal polarization and have low performance, because the waves go more directly to the towers.


for you have a idea.

Re: which polarization would you use?

Posted: Sun Aug 27, 2006 10:51 pm
by raffacol
but, in horizontal, the perfomance speed is 2mbps, with vertical go up to 3.5 mbps
due to the fact that power lines are horizontal ?

Re: which polarization would you use?

Posted: Mon Aug 28, 2006 3:06 am
by aitsecurity
but, in horizontal, the perfomance speed is 2mbps, with vertical go up to 3.5 mbps
due to the fact that power lines are horizontal ?
the problem no is the power lines, is the tower for power lines,

the tower is big, and when put the antennas in horizontal, the wave go vertical and shock more with tower. (i don`t know is shock the perfect word for this).

in horizontal the wave shock with ground more, and the tower.

in vertical is less to the tower go to left and right the tower, in horizontal the wave go up and down to the tower. the tower is more obstruction

i try in my bad english explain this.!!

Best regards