Wi-Fi client surge forcing fresh wireless LAN thinking

Wi-Fi client surge forcing fresh wireless LAN thinking

Carnegie Mellon University, which saw 1,000 brand-new Wi-Fi clients appear on its campus wireless LAN this past semester, is experiencing the kind of device surge that's forcing IT groups all over to adapt to a new, more dynamic radio environment.

"There must have been a lot of iPhone, iPads and Android devices handed out [as gifts] over the holidays," jokes Randy Monroe, network operations manager at CMU in Pittsburgh.

IDC reports that twice as many smartphones and tablets, nearly all with Wi-Fi, will ship compared to laptops this year. The number of Wi-Fi certified handsets in 2010 was almost 10 times the number certified in 2007, according to the Wi-Fi Alliance. Tablets, e-readers and portable audio devices are helping to drive this growth.

The result is a very different wireless environment in terms of radio behaviors, Wi-Fi implementations, applications, usage and traffic compared to just a year or two ago. This raises a different set of issues from simply managing these mobile devices with tools from vendors like MobileIron and Zenprise.

BACKGROUND: Major Wi-Fi changes ahead

One complex result is that Wi-Fi infrastructures have to become more sensitive to mobile Wi-Fi clients. That's not easy because the IEEE 802.11 wireless LAN standard puts the client in charge of connections, the opposite of a cellular network where the infrastructure takes charge of the client's behavior. (This is changing with new IEEE standards and clever vendor engineering. See "Major Wi-Fi changes ahead.")

It's also increasingly common for users to have two -- or more -- Wi-Fi devices, such as a laptop and smartphone, and to use them both at once.

In a typical week this past spring at Simon Fraser University in Burnaby, British Columbia, Canada, network statistics showed about 22,000 unique users. About 14,000, or two-thirds of the total, had only one MAC address, indicating a single client. That means roughly one-third of the users had two or more MAC addresses; nearly 5,400 had two, and just over 1,000 had three, according to Craig Simons, a manager with the school's network operations group.

Many schools report that the vast majority of the traffic they see with these new clients is Web traffic, and much of that is video related -- watching YouTube or streaming movies or TV shows from Netflix.

What's more, the new mobile devices really are mobile: Users may be streaming music or video or making VoIP or video calls over Wi-Fi while on the go. By contrast, although laptops are portable, in practice they're usually stationary when being used.

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