Potential Testing Standard for WLANs

By Eric Griffith

March 10, 2004

The Wireless Performance Prediction group in IEEE 802.11 could lead to an industry-wide test methodology for Wi-Fi.

You haven't heard of Wireless Performance Prediction (WPP), the latest Study Group in the IEEE's 802.11 Working Group? Join the club. It's not a secret, but it's hardly a household word even in Wi-Fi circles.

Azimuth Systems of Acton, Mass., is the company that's pushing for the establishment of WPP as an 802.11 Task Group, the type of group that gets assigned a letter to become an eventual standard -- or at least as a "recommend practice" for WLAN vendors (see below). Azimuth's chief scientist, Charles Wright, is the chair for the WPP SG that was formed at the IEEE 802.11 meeting in January in Vancouver, B.C., Canada.

Next week, the IEEE 802.11 Working Group meets again in Orlando and is hosting a March 15 tutorial on WPP for members to get the full scoop.

Which brings back the question: What is WPP supposed to accomplish?

Fanny Mlinarsky, CTO and founder of Azimuth, says the group exists to communicate the need for standardized metrics and test methodology in wireless LANs. Take for instance "how to specify roaming time for voice communication... there's no agreed upon methodology on even how to start and stop measurement," she says.

The WPP SG includes members from companies such as Intel, HP, Microsoft, Dell, and Broadcom. Azimuth itself makes wireless data communications testing equipment and would, of course, benefit from additional testing metrics being applied to the existing Wi-Fi standards.

The WPP SG is in a "request for proposal" stage trying to find and catalog all measurable traffic patterns according to Wright.

Mlinarsky says when customers want to measure things one way and vendors do it another, confusion reigns: "The industry has to come together on how to test."

The WPP is not meant to supplant the work of the Wi-Fi Alliance -- that third-party vendor consortium exists to test for interoperability between products, not to measure network traffic and specifications.

Conversion of the WPP SG to a Task Group wouldn't happen until the July IEEE 802.11 meeting at best, says Wright. However, just because the WPP is currently a Study Group doesn't guarantee its future as an 802.11 standard complete with letter suffix in the IEEE.

It's entirely likely that WPP could end up as a more general "recommended practice" -- but Mlinarsky says it was such practices that transformed the use of Ethernet years ago.

Mlinarsky equates WPP to testing standards established years ago for Ethernet. "Years ago... if you didn't come out in first or second [with Ethernet] you lost billions in market share. No one's really done this for Wi-Fi yet; there's no agreed upon way for it to work."



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