Comparison of Cisco and Aruba's RF Automation | 7SIGNAL | Blog

Wi-Fi RF automation is a hot topic. Not because it’s new (it’s not) but because there are strong believers and non-believers. The discussion lacks facts and measurement data, which we will cover in this 2-part blog.

7signal worked in cooperation with Avans University of Applied Science to characterize 802.11ac Wi-Fi performance and behavior in their environment. We compared and contrasted the RF automation behavior of two market leading Wi-Fi companies.

The Test Environment

The test environment consisted of two learning centers on the university's campus.  The existing Wi-Fi access points were replaced with each vendor’s solutions for one week each. Wi-Fi performance was measured by 7signal's system of Sapphire Eye sensors and Mobile Eye apps for devices.

Learning Center 0

• Seven access points, of which 6 were measured
• Aruba AP225, SW version 6.4.3.7 (1 week)
• Cisco AP2700, SW version 8.1.131.0 (1 week)
• One 7signal Sapphire Eye 2100

Learning Center 1

• Seven access points, of which 5 were measured
• Aruba AP225, SW version 6.4.3.7 (1 week)
• Cisco AP3700, SW version 8.1.131.0 (1 week)
• One 7signal Sapphire Eye 2100

Special focus was on 5 GHz channel selection operation.

Each week began with four fixed 20 MHz channels and fixed power levels, with no RF automation enabled. Channel power levels were equal in both cases, following the manufacturer's recommended power level settings. All other access points in the Learning Center used this configuration over the testing period. Each test period lasted from the previous week Friday afternoon until following week Friday afternoon.

Tuesday evening, RF automation was turned on and all allowed channels (European channel allocations) were enabled. In addition, power control was also enabled. The default settings for RF automation were utilized and channel bandwidth was kept at 20 MHz.

Some interesting and important observations were made. We will label the vendors as A and B. You can have a little fun guessing who is who.

RF Automation Switched ON

Below are graphs representing the power levels from 7signal's Sapphire Eye sensors. You can see on floor 0 and floor 1 how the levels quickly changed once RF automation was switched on.

Floor 0 Power Levels

Floor 1 Power Levels

My Key Takeaways

• RF automation substantially increased power levels in both cases.
• Vendor A's  initial static power levels appears to result in a higher received power level, despite similar settings.
• After turning RF automation ON, Vendor A’s power levels remain higher than Vendor B’s.

A Closer Look at Channel Balance

One of the key promises for RF automation is to allocate channels in a balanced manner at any given time.  Let’s take a look at these allocations at different times.

The chart below displays the 4 static channels that were used before the test period, as well as during the test period, but outside our test environment.

Now let’s look at the average channel allocation with RF automation switched ON. In the chart below, both vendors are compared for each floor.

Floor 0 Channel Allocation

Floor 1 Channel Allocation

My Key Takeaways

• Vendor A balances the channels relatively well channels across the available spectrum. I see some room for improvement, however, as some individual channels still have a high number of BSSIDs.
• Vendor B's channel allocations are heavily concentrated to the lower channels. This is a very undesirable behavior.
• After enabling RF automation, Vendor B still allocates channels 36-48 to APs in this area. This happens despite the fact that they are already used by other APs in the building. This leads to a high concentration at low channels.
• Vendor A clearly performs better than Vendor B. Can you guess who is who yet?

Stay tuned for part-2 of this blog series where we will review the data for channel stability and air utilization and how both are affected by RF automation.