The IEEE will remove a major obstacle to the widespread use of Wi-Fi for serious business applications with the creation of a testing group that plans to define standards for measuring, comparing and predicting the performance of Wi-Fi equipment.
Unpredictable performance is a bugbear for enterprise Wi-Fi. The actual performance of a wireless network, in a given location under specific applications, can vary far more than that of a wired network, leading many IT managers to relegate it to the conference room and other non-critical use. The Wireless Performance Prediction study group of the IEEE — backed by Microsoft Corp., Intel Corp., Hewlett-Packard Co. and Broadcom Corp., as well as Wi-Fi test specialist Azimuth Systems Inc. — will look at the issues involved and plans to come up with standard ways to test and compare wireless performance.
“One vendor reported a 57 millisecond (ms) roaming time — the time taken for a device to disconnect from one access point and connect to another — while our tests showed 28.6 seconds,” said Bob Mandeville, president of Iometrix Inc., and a leader of the group. Unfortunately, he said, without a proper definition of roaming time, both figures are correct: “It depends on what you actually count as roaming time — whether you choose to include, or exclude, rate adaptation.”
“With that kind of disparity you need someone to stand up and say what the actual number is,” said Mandeville, who will launch the group with a tutorial on March 15. As the author of two standards for testing of wired Ethernet, the IETF’s RFC 2285 and 2998, Mandeville hopes to see this group achieve similar standards for Wi-Fi.
The group has the right credentials. Its initial chair is Charles Wright, chief scientist of the leading Wi-Fi test specialist Azimuth, who launched a major Wi-Fi test system in November. Its membership also includes the University of New Hampshire’s Interoperability Lab (UNH-IOL), which has developed test suites for Wi-Fi standards and been instrumental in Wi-Fi’s progress.
However, as with most standards, there’s a long haul to get through first. So far the WPP has “study group” status: “That is a stepping stone to creating a working group,” said Mandeville. “The aim of the study group is to convince the IEEE body that it is worthwhile to create a standard.”
Mandeville expects the group can make the jump to a standards-making group in six months and have a completed standard two years later. Tests will become available well before that, in order to try out the ideas the group comes up with. “There have to be implementations,” he said. “You can’t take the risk of standardizing something that hasn’t been thoroughly tested in the field.”
