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."
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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.
"The issue is about managing the access points," he says. "If they need to cable up every time it defeats the whole object."
There are potential problems. 11ac may have a shorter range, but over time this could encourage a proliferation of APs, and if those from different networks are relatively close they can interfere with each other.
Also, while 11ac will be able to bond more channels to increase throughput, this can reduce the number available and create a situation where adjacent APs try to share a channel but only one can use it. Radio resource management technology can help to prevent this by monitoring the networks and access points in an area, but Terminiello says the pressure will increase.
"There will be a point in the future, maybe five or six years, when everybody starts deploying wave 2 11ac, when we get down to two or four channels in the spectrum and it will make channel planning more difficult," he says.
Security is also an issue. Terminiello says that, while most suppliers are likely to incorporate the WPA2 security protocol and the Advanced Encryption Standard in equipment, there are worries that some vendors will support older and weaker standards.
Kilpatrick says there are vendors "selling wireless access, not secure wireless access," and warns buyers to think carefully about security from the beginning.
"The problem, and this is endemic, is that people see the benefit of something, deploy it, and in the future, typically five years, begin to defend against it," he says. "Often they don't want to take the costs of reducing vulnerabilities with the initial deployment; but if they wait until they get hacked the costs are going to be much heavier."
He also has a broader concern abut 802.11ac, that people will simply begin laying its APs over their existing 11n networks and create problems for the future.
"It will cost them a lot of money and at some point in the future they will have to redesign the lot because they started at the wrong place," he says. "You've got a structure that's going to migrate from 2.4GHz to 5GHz, which means all those 2.4GHz access points will become redundant at some point in the next 18-24 months. Then you've got a whole overlay where you've got to put in more cabling as you add more access points."
His advice is to think about it strategically, not tactically, as this will ultimately prove more productive and less expensive.
Terminillio plays up the positives more, but also tells people to begin planning now.
"The stand out piece is that 802.11 ac is coming, so embrace it and start to plan for it, because it offers major advantages in throughput, quality and coverage. It's already on some smartphones and tablets and it will only increase over time."