Cisco 1242 AP 5Ghz Antenna for Warehouse

Unanswered Question
Sep 27th, 2010

Currently have access points located throughout our warehouse that use the AIR ANT5160V-R antenna's from Cisco. These AP's are 25' in the air. However we have a lot of voice quality issues off of the 5Ghz band, we do no other services on this band as we keep data on the 2.4Ghz.

This was all installed by a vendor but from what I am seeing on the documentation, the cover is extremely poor for these antennas despite AP's everywhere. They cover side to side but aren't a well rounded AP at all.

Does any have experience with these antenna's or know more information? Its just from what I am seeing, the vendor took us down the wrong path and we have the wrong antenna's for the job.

It seems like the AIR-ANT5145V-R would be better suited even though this is a warehouse.

Any and all feed back would be greatly appreciative.

I have this problem too.
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Leo Laohoo Mon, 09/27/2010 - 15:02

I presume that your vendor installed two of the antennae per AP or just one?  I wonder if diversity is turned off or on.

25 feet in the air ... Hmmm ... Optimally, this type of antennae is to be installed between 10-15 feet and hanging downwards.   The probable reason why this was chosen is because of the mid-level gain.

In a horizontal plane, this antennae transmit all around (good) but on a vertical plane, there can be "shadows" or "lobes" where you don't get signal in an area but if you move forward/backward the signal improves.

ericn8484_2 Mon, 09/27/2010 - 18:47

Hi Leo,

While I dont have the system in front of me to double check, they are suppose to be in diversity mode and we have 2 antennas per 1242 AP. However these are all 25-30' in the air facing downwards. The lobes on these Antenna's just dont seem to cover a wide area very well.

What I have been looking at is we just purchase FlukeNetworks wireless survey pro system and when I have AP's configured for 25' in the air, the coverage shows very very poor which reflects a lot in what we are seeing with these antenna's. It seems like the 5140 antennas would be a better fit for coverage.

Leo Laohoo Mon, 09/27/2010 - 19:13

It seems like the 5140 antennas would be a better fit for coverage.

Hold on!  You "can't" use the 5140 because:

1.  This model has a lower gain:  4 dBi; and

2.  This model has THREE (3) pigtail because it was made for the the 1250/1260 and 3500e access point.

I guess you can try to use this but don't connect the middle RP-TNC connector.  Haven't seen nor heard anyone trying this way.

Another method to test whether or not the antennas are installed too high is to lower it to about 10 to 15 feet from the ground.

etmarcof Tue, 03/06/2012 - 12:44


Have you managed to solve  your problem? if yes can you please share?

Best Regards


ericn8484_2 Wed, 03/07/2012 - 05:22

Hi Etmacrof,

What AP are you using? I am not aware of a better Antenna for the 1242's. I have heard there are newer ones for the 3500 series but can't confirm that.

The way we have helped with our wireless coverage is first going with the latest stable release of the wireless controller firmware, if you are using Cisco Wireless phones, try and get their firmware up to the latest.

The other item that I did that I changed is on the controller, I set my 802.11a/n RRM-TPC settings so the Power Threshold is at -60dBm. What this setting does is allow the access points to increase their power on the A band so they see each other at -60dBm, I think the default is -75dBm. With the increase in power, the coverage was a little better, still not perfect though.

The downside to this setting is you see a lot more possible access points when performing a scan. This can be problematic if you have wireless devices that can't handle seeing a lot of AP's. I would not recommend changing this on the B/G antenna's because there are not as many available channels for the AP's to use without creating significant interference.


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