High-Density WiFi: Planning for the Future

Wireless develpment didn't end with 802.11n. With new, higher-speed specifications looming, plus the ever-increasing demands of 1-to-1 and BYOD programs in schools, planning for the future in wireless implementations is just as crucial as ever.

• By Chris Riedel
• 01/30/12

"The conversation around 1-to-1 computing lasted for a few months," said Perry Correll, director of marketing for Xirrus, in a session he led at the FETC 2012 National Conference in Orlando Thursday. "Then everyone showed up to class with multiple WiFi-enabled devices, and suddenly the conversation changed."

The success of that conversation, according to Correll, hinges on planning for the future. "In 2011," he said, "8.5 million tablet and smart phone devices were activated the day after Christmas. Kids will be bringing these to school." The only question now is, how are we going to handle it?

Understand the Impact
According to a recent Gartner study, by 2015, 80 percent of newly installed wireless networks will be obsolete due to a lack of proper planning. The same study also found that, without out an effective plan, enterprises deploying iPads today will need 300 percent more WiFi just to be effective.

"The problem," said Correll, "is that students just expect these things to work," and that expectation has the potential to drive the decision making process and undermine planning. "But there are smart ways to implement effective wireless networks," he said. "You just have to understand the needs."

Understand the Specifications
WiFi has undergone a significant evolution over the last 15 years, according to Correll, "but the biggest obstacle is that people still don't completely understand the implications of these specs on their actual, local networks."

Correll insisted that it's important to understand that 802.11n covers two standards: one operating in the 5 GHz range one in the 2.4GHz range. Why does this matter? Because, said Correll, if schools buy devices that are 802.11n compatible but are not dual-band, they will only ever operate in the 2.4 GHz range; and that, he said, "will prevent you from ever going 1-to-1."

Understand Your Needs
The biggest factor in poor performance, said Correll, is density. "The more people you have on a radio, the more chance there is for collision of data, resulting in slower speeds and, ultimately, more complaints."

In order for your network to be effective, he said, "you have to know two things: How many people do you expect to serve, and what are your users expectations of the network?"

If you don't know both of these things, you can't develop a plan to address either one.

Design for Growth
According to Correll, in the last two or three years we've seen a clear "line in the sand," showing us where networks need to be in the very near future:

1. Coverage must become ubiquitous;
2. Signal strength must be designed for tablets and smart phones; and
3. Networks must provide coverage for both 2.4 GHz and 5 GHz devices.

"What this is really telling us," he said, "is that we have to design our networks for growth. We have to design them for what we might need in the future, not what we need right now." A big part of that, he said, lies in designing for 5 GHz devices. "It's not that 2.4 GHz is going away; in fact, each has its own set of advantages. But by designing for 5 GHz, you actually improve performance for 2.4."

Plan for Performance
Right now, Correll said, wireless performance is on par with wired. But with two new standards on the horizon--802.11ac and 802.11ad--it's important to keep an eye on the future and plan for devices that will require "better-than-wired" capabilities. "The irony here," he added, "is that 11ac- and 11ad-compatible hardware is exactly what you want to buy, but no one needs it right now."

Still, said Correll, even though you don't need it now, you should plan for it by finding solutions that offer a clear upgrade path to ac/ad. "And don't worry about backward compatibility; that's a requirement written into these new specifications."

Other things to consider when planning an effective wireless network include:

1. Finding hardware that has controller intelligence built in, to improve traffic flow and reduce bottlenecks;
2. Selecting client devices that are dual-band (2.4 GHz and 5 GHz), not simply 802.11n or 802.11b/g/n compatible;
3. Remembering that "5 GHz" is more important than "802.11n"; and
4. Understanding that, no matter what you do, there will always be client types that can bring even the best network to its knees.

Prepare for the Future
"It's not enough to know what's out there," Correll said, you have to actively prepare for what your users will eventually need. BYOD is a great example, he said. You can--and should--be identifying classes and types of devices right now. "Classifying devices and managing your network based on this information is a great way to improve performance." By setting rules per device-type and/or individual user role, you will be able to balance your load more effectively and make important decisions about who and what devices are--and will be--using your network, now and in the future.

Most import of all, said Correll, is building a flexible solution that can adapt to future needs as they arise. "Too much WiFi," he said, will never solve the problem. Effective, thoughtful planning will.