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Antenna Gain(dB)? (-128 - 128 dB) at 1200AP

Level 1
Level 1

Hi. I recently purchased a 1200AP , Cisco IOS Release 12.2(15)JA later.

I'm trying to "External Antenna Configuration" and "Antenna Gain(dB)" ,

but how much Antenna Gain(dB)? (-128 - 128 dB) ?

Thanks for any help,


5 Replies 5

Level 10
Level 10

The idea is to match that value with the antenna that you have connected.

The standard "rubber duckie" antennas are 2.2db.

I believe that setting will control the output to the antenna to keep the unit within spec for Effective Isotropic Radiated Power (EIRP).

Just set that field to whatever the gain value of the antenna that you're using.

Good Luck


Why the Antenna Gain(dB) (-128 - 128 dB) at 1200AP

has minus quantity range and how to controll EIRP ?

As we konw antennas gains are positive numbers .

Any one can help ?

Level 4
Level 4

Negative dBi values generally indicate observed signal strength at the receiver. In this case, I suspect it's a reference to receive sensitivity.

Can you clarify exactly what screen you're on in the GUI or what IOS commands you're using, when you see this figure?

Level 1
Level 1

May 20, 2004, 7:17am PST

The engineer is referring to this new item in IOS 12.2(15)JA under the Network Interfaces - Radio0x- Settings.

External Antenna Configuration:Enable/Disable

Antenna Gain(dB):(-128 - 128)

What this is for is to specify to a WLSE when it is doing a assisted site survey that you have external antennas attached to the access point and the gain of those antennas.

The WLSE takes that into account when creating the site survey.

If you do not have a WLSE and are not doing assisted site survey there is no need to adjust or enable these settings.

Hopefully this will be documented ASAP in the online help and in the configuration manual.



So, Where can a person find the Antenna Gain (dB): ?

I have a 5.2dBi Ceiling Mount OMNIDIRECTIONAL antenna part #: AIR-ANT1728. What is the Gain?

I'm trying to enter the setting on a AIR-AP1231G-A-K9 (12.2(15)JA) for a WLSE 2.7.1 but, I'm not sure what is the numeric equivalent. Or is it as easy as -5.2 - 5.2?

Any help is appreciated

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