What will 802.11ac mean for the workplace?

Wireless abstract
Time to think about moving from n to ac

You're going to hear a plenty of talk about 802.11ac in the coming months. It's the new draft standard for wireless networking developed by the Institute of Electrical and Electronic Engineers Standards Association, it's expected to be ratified in September, and it will have big implications for office networks.

Under 802.11ac local area networks will operate on the 5GHz band, compared with 2.4GHz on the existing 802.11n standard, and make it possible to move data at rates as high as 1Gbps, up from 600Mbps. It will also provide for more multiple input, multiple output (MIMO) antennas, making it possible to create eight spatial streams compared with four with 802.11n.

The practical effect will be to support more clients from a single access point (AP), and make more bandwidth available for a higher number of streams. In short: it will be able to support a lot more mobile devices on an office network.

Small business boost

This can be an asset for small businesses, according to Ian Kilpatrick, Chairman of IP infrastructure distributor Wick Hill Group.

"It can give you the capacity to deal with whatever is coming through the pipe at the moment," he says. "Previously you would not think of doing it on wireless as it would eat your bandwidth, and it will give smaller businesses the flexibility to grow and move around."

As many offices move to relying more on mobile than fixed line devices, this will help in providing more consistent coverage around the space; although whether the clients will obtain the maximum speeds can depend on the types of clients, how many spatial streams they need and their distance from the access points.

In the short term there will be a further benefit, as most companies will continue to use 802.11n and there will be more space for those on the new standard.

Carlo Terminiello, Technical Lead for EMEA Mobility Sales at Cisco Systems, says: "There are more channels available at 5GHz and you're less likely to meet other networks, which means better throughput because there will be less interference."

But it will be a benefit that could eventually evaporate.

"Vendors have picked up on the fact that 2.4GHz in many environments is really over-subscribed, and it's quite difficult to deliver a consistent scalable service using 2.4GHz. They started a couple of years ago to support more 5GHz endpoints, and as that change happens the excess capacity will be consumed."

He adds: "But it will happen slowly. We still come across customers with 2.4GHz only networks deployed today, and we have to explain the advantage of 5GHz, so they really need to start designing their networks to support the new frequency."


Terminiello acknowledges that this will involve a significant investment, and that as with any relatively new technology it is more expensive before being widely adopted. But he also makes the point that demands on wireless networks are going to increase, and if companies want to make full use of the rich media available they will have to upgrade.

It will be possible to combine the operation of the new and old standards so you can move gradually to 11ac. He says that Cisco is among the suppliers that provide dual band access points that work on 11ac and the earlier n, g and b versions, which makes it possible to support legacy and new devices simultaneously.

There is also a need for some thoughtful planning. Kilpatrick says the new access points will have to be placed carefully. 5GHz is a shorter range than 2.4GHz by a factor of about two and half, so it will initially be easier to avoid interference, but it will also be necessary to ensure it can reach all the parts of a building where people will need to access networks. The access points will also have to be cabled, and if a lot of new cabling is required it will prove expensive.