Cisco Patch Antenna (AIR-ANT2566P4W-R)

I have had some experience deploying the Cisco AIR-ANT2566P4W-R 2.4-GHz/5-GHz MIMO 4-Element Patch Antenna in both indoor and outdoor environments. One thing that I found was quite a lot of people deploying this antenna didn’t realize that it makes a difference in how you connect up the antenna to the access point.
The reason it is probably not well known is as it is not detailed within the AIR-ANT2566P4W-R deployment guide. In the deployment guide for 1600/2600/3600 access points there is a little mention of how to connect this antenna.

Whilst in most MIMO antennas connecting to these APs there isn’t any difference regardless of how you connect the antenna leads to the AP, the design of the patch antenna means that the elements are side by side within a plastic housing so there is an improvement by connecting the outer elements on the antenna to ports A and B on the AP. The below image shows which lead should go to which antenna port on the AP.PAtch.jpg

I have conducted the experiment to show the difference between connecting the AP as per the image above and also with connecting the AP as most people do Lead 1 to A Lead 2 to B and so on.
I took readings at 5, 10, 15, 20, 25 ,30 meters in a straight line of of site for both 2.4 GHz and 5 GHz with a power of 25mW on each band. The results are listed in the tables below all values in dBm. I utilised a Cisco 3602e access point to connect the antenna to.

2.4 GHz

Cabling (Antenna to AP) A to A, C to B, D to C, B to D  

Distance(m) Ekahau Site Survey Netscout Aircheck G2 Fluke Aircheck Average
5  -45  -50 -48  -47.7
10  -50 -51 -50 -50.3
15  -54  -58 -57 -56.3
20  -52 -56  -53  -53.7
25  -53  -64 -58 -58.3
30 -52 -55  -50  -52.3

Cabling (Antenna to AP) A to A, C to C, D to D, B to B

Distance(m) Ekahau Site Survey Netscout Aircheck G2 Fluke Aircheck Average
5 -45  -45  -42  -44
10  -45 -52  -47 -48
15 -48 -56  -51  -51.7
20 -49 -54 -49  -50.7
25 -45  -63  -56 -54.7
30 -55  -56  -54  -55

Differences:

Distance(m) Difference based on the average (dBm)
5 3.7
10  2.3
15  4.7
20 3.0
25  3.7
30 -2.7

5GHz

Cabling (Antenna to AP) A to A, C to B, D to C, B to D

Distance(m) Ekahau Site Survey Netscout Aircheck G2 Fluke Aircheck Average
5 -44 -52  -42 -46
10  -53 -52  -52  -52.3
15  -54 -55 -55 -54.7
20 -56  -60 -56  -57.3
25 -60  -64  -62  -60
30  -57  -61 -58 -58.7

Cabling (Antenna to AP) A to A, C to C, D to D, B to B

Distance(m) Ekahau Site Survey Netscout Aircheck G2 Fluke Aircheck Average
5  -46  -49  -44  -46.33
10  -52  -55  -50  -52.33
15 -52 -58  -52  -54
20  -57 -56  -51  -54.7
25  -59 -59  -59 -59
30  -56  -60 -55  -57

Difference

Distance(m) Difference based on the average (dBm)
5  -0.3
10 0.0
15  0.7
20 2.7
25  3.0
30 1.7

As you can see its not a huge difference less than 5dBm, and these tests were not undertaken in a lab environment so there could have been external factors playing into the results, but it definitely pays to connect the antenna correctly.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s