Adding a Lane to Your Wi-Fi Commute

Share Post

Have you ever sat in traffic and wished there was another lane? I've been making this wish a lot lately, as my commute seems to be getting longer each day. While sitting in traffic this morning I started thinking about what causes traffic congestion and I realized there are a number of parallels between traffic and RF engineering.

Whether you are talking about more cars on the road or more devices on the Wi-Fi network, traffic and RF engineers both need to figure out how to make the best use of a fixed resource.  I'm not sure about the life of a traffic engineer, but the life of an RF engineer got a lot better with the introduction of 802.11ac.

802.11ac brings gigabit speeds to Wi-Fi and doubles the channel width of 802.11n by allowing 80-MHz channels in 5 GHz. By doubling the channel width, you double the speed. Faster speeds mean devices take less airtime to receive the data, so you can support more devices on the network with less congestion.

Aruba maximizes this opportunity by supporting all five 80-MHz channels available in the U.S.  Whether you're deploying 802.11ac in a large campus or a retail store, the ability to use all five channels reduces the performance-robbing effects of co-channel interference and maximizes channel re-use.

There are actually six 80-MHz channels available, but channels between 116 and 132 are used for weather radar, so the maximum available for Wi-Fi is five 80-MHz channels: 36E (36, 40, 44, 48), 52E (52, 56, 60, 64), 100E (100,104,108,112) and 132E (132,136,140,144) and 149E (149,153,157,161).

11ac cp.png

I was bit surprised that Cisco only recently started talking about radio management support for 80MHz channels and shocked when I found out that they don't even support all available channels. I guess they don't mind sitting in traffic. As you can see below, Cisco does not support 132E, since Channel 144 is missing.

Cisco traffic.png

By supporting all five 80-MHz channels, Aruba has an immediate 25% performance advantage.

Aruba v Cisco 80MHz Channels.png

The next time you're stuck in traffic, ask yourself how great life would be with that extra lane.