When Should You Upgrade to 802.11ac?

802.11ac is a big buzzword in education IT right now. Everyone is talking about it and vendors are pushing products out the door. The big question for the IT administrators who deploy and manage WiFi networks is when do you actually purchase it? Is it now? Is it in January? Do you wait for Wave 2-(see 5:20 on the video)?

Andrew von Nagy:

However, we need to temper our short-term expectations. The first wave of 802.11ac equipment will likely not prompt upgrades to existing WLAN deployments unless it is replacing older gear; it just won't provide enough value to justify the replacement of the latest generation of 802.11n equipment.

I've got an 802.11n network that was deployed in early 2012. I am looking forward to 802.11ac, but ripping out my entire WiFi network is not in my immediate plans. If I have to add APs for new areas, I'll certainly add 802.11ac APs, though. 802.11ac can also make an immediate impact in high density areas.

Matthew Gast:

Networks will not need a full refresh cycle of client devices to benefit from the upgrade to 802.11ac. Even a few 802.11ac clients can benefit from an 802.11ac infrastructure because of the way that packet-switched networks respond when faced with congestion. Congestion is unfortunately a fact of life in networking, and it’s something that network technology designers have to deal with. Packet-switched networks cope with congestion well, up to a point, and then they suffer from a sudden collapse.

I am not saying that there is no technical reason to upgrade to an all 802.11ac network now, though. The ROI for my organization just isn't there yet. I have to live in the circle where technical opportunities and business realities intersect. I have a set budget and I have to make our network function off that amount of money.

More from Matthew:

So, what’s the “bicycle fix” for Wi-Fi? We have a fixed and costly resource – the radio medium – and need to wring more out of it. By reducing the transmission time for frames, 802.11ac enables network administrators to push back against congestion collapse. The lesson in here is that if you have a network running close to the traffic volume at which congestion takes hold, you should move to 802.11ac. As you add 802.11ac clients, they will reduce the amount of airtime required to transmit data, and increasing free airtime will improve the quality of user experience for everybody.

This is also the reason that I hardwire any device that is stationary. I want to free up airtime for mobile devices/WiFi only devices.

Remember, speed is just a slice of the pie that matters with WiFi. Just as you consider more than speed when buying a car, you need to be looking at the overall package. How does a system scale up as you grow? How do you manage it? Does it offer application control? Does it require a controller (run for the hills if it does)? If you are only concerned with speed, then you are buying a sports car. I want the Honda Accord solution. I want the one that provides the best overall value for my organization.

I'll likely move to a full 802.11ac network in early 2015. We just did a device refresh with MacBook Airs (in March so they are 802.11n) and iPad minis. We have a 3 year lease, so we won't have a mass adoption anytime soon. The more time I can squeeze out of my current N network, the better 802.11ac hardware that I will end up with. So when should you update to 802.11ac? If you are doing a new deployment today, I'd definitely look at 802.11ac. If you deployed 802.11n back in 2007, then I'd probably look at moving to 802.11ac as soon as your vendor has products. If you have an existing 802.11n network that is meeting your needs, then I'd probably just keep using it until it's fully depreciated and has run it's course.

Helpful Resources:

Why 802.11ac helps every network

First look at 802.11ac

Safely Using 80 MHz channels

The impact of 802.11ac on Enterprise Networks

Planning Your Network

802.11ac Survival Guide

Extending Battery Life with 802.11ac

Selecting Data Rates in 802.11ac

Matthew Gast at Wireless Field Day 5 on MU-MIMO