Hi All,

I wanted to post the following information because it is becoming a frequently asked question. Please reach out to me if you need any further clarification.

Motorola dual radio AP7131 has two 10/100/1000 Mbps ports – LAN and WAN. The radios use 3x3:2 MIMO 802.11n transmissions. Under full power conditions PoE+. All of these components are active. In a simultaneous dual radio downstream IPerf TCP test we achieve 247.1 Mbps throughput. Under 802.3af power conditions, we turn off the WAN port completely and our radios use 2x3:2 MIMO for transmissions. Under 802.3af conditions in the same test we achieve 244.6 Mbps. Test report and test summary are available at links below. Aruba uses the exact same method to achieve PoE compliance. They shutdown the wan port and go from 3x3:2 MIMO to 2x3:2 MIMO. In the same test outlined above Aruba goes down from 159.8 to 147.7 Mbps. Cisco has only one 10/100/1000 Mbps port so it does not have to shutdown any Ethernet ports. Cisco always uses 2x3:2 MIMO configuration. So it can continue to use the same MIMO configuration. In the test outlined above Cisco throughput goes down from 204.9 to 107.3 Mbps.

So you have to point out that even though Aruba and Motorola use the same method, Motorola AP7131 achieves superior performance under 802.3af. In fact the tests conducted showed that Motorola outperformed Aruba under all scenarios.

http://compass.mot.com/doc/326497756/AP7131_PoE_Compliance_and_Performa…

http://compass.mot.com/doc/326461247/Comparing_Motorola_Cisco_Aruba_802…

Vendor AP

Performance (in Mbps) – Full Power

Performance (in Mbps) 802.3af Power

Performance Drop %

Motorola AP7131

247.1

244.6

1.01 %

Aruba 124

159.8

147.7

7.57 %

Cisco 1140

204.9

107.3

47.63

One of the things you should know about Aruba APs is that there are only 3 antennas that are shared by both radios. Clearly this is a disadvantage when it comes to mesh backhaul scenario. Typically APs are mounted on the ceiling or high up on the walls. You would want to point the antennas down for client access and point them towards other APs for mesh backhaul. This of course depends very much on the antenna type. The point is that AP7131 has the flexibility to do this because there are 6 antennas- 3 per radio whereas Aruba AP shares the 3 antennas between the two radios.

-Rajiv Iyer