Access Points

Occasional Contributor II
Posts: 11
Registered: ‎04-13-2009

AP124 With AP-ANT-16 - Weak 5GHz signal?

Hello Airheads,

Has anyone of you experience with the combination of an AP124 with the AP-ANT-16? I'm currently rolling out this combination in a hospital environment, and with both radios (g and a) set to equal TX-power levels for some testing I'm experiencing quite different signal levels (5GHz being 12 to 20 dBm weaker than 2.4GHz) for both radios standing 5 to 10 feet away from the AP. I know the 5GHz signal behaves different through walls etc., but in open space I have the experience with several types of AP's (65, 105) that signal levels at the distance described, and with equal TX-power are nearly the same.

The trigger for this question is that I'm having a stable connection at -72dBm/65Mbps with 2.4GHz, but -72dBm with 5GHz results in an unstable connection at 6Mbps. The SNR is always 20dB or better. Initially I disabled HT on the 2.4GHz, but for a fair comparison I enabled it on both radios (which are having equal configs now).

We tested this setup with different Intel 5100 and 5300 cards, and we also "re-verified" the signal levels with Airmagnet.

Any experience or suggestions are greatly appreciated.


Posts: 1,282
Registered: ‎11-07-2008

Re: AP124 With AP-ANT-16 - Weak 5GHz signal?

have you tried disabling ARM on that AP and set both radios statically to a channel and max power? When you run a 'show ap active' what is the radio output? When you provisioned the AP did you put in the correct antenna gain values in the proper 2.4GHz and 5GHz fields?

I would check all the cables and make sure everything is correctly connected. Also, have you seen this on multiple APs or just one? Do you have any ANT-1Bs to test with and re-test the signal seen? Sorry if these are things you have already tried.
Jerrod Howard
Sr. Techical Marketing Engineer
Occasional Contributor II
Posts: 11
Registered: ‎04-13-2009

Re: AP124 With AP-ANT-16 - Weak 5GHz signal?

Thanks for your reply!! I disabled ARM on both radios, and set them statically to max power (20/20 on 2.4 and 5GHz). I used the correct antenna gain values for both radios, also the cables where correctly connected (and not overbended etc.). I've seen this on multiple AP's, but didn't had the chance to test with other antennas.

Today I was at another site, and had the chance to test with the the same AP (124) and a different antenna AP-ANT-14. In this case at max. TX-power the received signal strengths of both radios where equal.

By the way: what's the minimum signal strength you would recommend for a stable 802.11n connection (minimal speed > 60Mbps) @5GHz? The unstable connection at -72dBm/5GHz was the trigger for this topic.


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