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New Member

Antenna gain setup with 1310

I have the 1310 outdoor AP with the 2.4 GHZ 5.2 dBi Omni antenna. On the setup for the AP it asks for the external antenna's DB gain. Do I enter 5.2?

1 ACCEPTED SOLUTION

Accepted Solutions
Green

Re: Antenna gain setup with 1310

That is correct.

Good Luck,

Scott

5 REPLIES
Green

Re: Antenna gain setup with 1310

That is correct.

Good Luck,

Scott

Hall of Fame Super Red

Re: Antenna gain setup with 1310

Hey Scott,

Long time, hope things are going well for you!

I thought in this instance you just used the whole number (ie: 5) or does it even matter since this is more of a reference number than anything else?

Take care!

Rob

Green

Re: Antenna gain setup with 1310

Yessir, you are correct, good catch.

I tried it, the system only takes whole numbers between +128 and -128 (wouldn't an antenna with 128dbi of gain be interesting?)

It is my belief (as in, it makes sense to me, I haven't really read anything about it) that the AP may use that number to "throttle back' the gain to keep the EIRP in compliance with the region's standards (though, there's no field for "What kind, and how much cabling are you using?" which would be the other factor for that calculation).

Since I do mostly indoor systems (and only a very few at that), I have never paid much attention to that field.

The "Help" screen for that setting says:

(quote)

Antenna Gain(dB)

The gain of an antenna is a measure of the antenna's ability to direct or focus radio energy over a region of space. High-gain antennas have a more focused radiation pattern in a specific direction. This setting is disabled on the bridge

(end quote)

-not a lot of help, what a surprise ;-}

Another other reason for putting that field in the config screen might be to keep the AP roles in-line with the antennas used (like: someone tries to put a 24db dish on an internal AP setting at full power and roasts all of the users).

It might be like the "bandwidth" statement on a router ... it doesn't actually affect the operation, but it does provide a value that the WLSE/management platform can use to map the radiation pattern.Though, on the WLSE mapping graphics, it permits you to enter the antenna type and height above the floor (no real reference for outdoor installations ....).

Next time I break out the field strength meter, I'm going to see if it does in fact actually throttle back the power or if it's just some kind of reminder / reference.

I'll see what I can find on it. So much for quick assumptions :) ...

Thanks again, keep up the good work!

Good Luck

Scott

Hall of Fame Super Red

Re: Antenna gain setup with 1310

Hi Scott,

As usual your humour is at its finest, and one of the reasons I love reading the posts on this forum! There probably are some users that we all wouldn't mind roasting :) (just kidding). Here is a tech note that seems to indicate that this setting has no actual bearing on the performance of the antenna, but is more of a reference or way to know the antenna attached to the AP without actually seeing it.What do you think?

Note This setting does not change the antenna gain, it is used to identify the gain of the installed antenna(s).

Note The antenna gain value is listed on the user document that shipped with your antenna.

From this doc;

http://www.cisco.com/en/US/products/ps5861/products_configuration_guide_chapter09186a00804158a8.html#wp1060543

Anyways, its always a pleasure to read your posts.(And I have learned a great deal to boot!)

Thanks!

Rob

New Member

Re: Antenna gain setup with 1310

I've done some testing in a live environment where we varied the antenna gain from 0 to 5 to 10 for a dipole antenna whose gain is 5.2. There was a difference in the cell size at each setting but it was not consistent around the whole cell and really it made little difference.

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