We tested handheld wireless LAN analyzers at our Syracuse University Real-World Labs®, a SOHO environment and a production WLAN environment on the Syracuse University campus--comprising a centrally supported WLAN, a departmental research system and an array of "rogue devices," mostly WLAN gateways installed in offices. Our test environment represents a classic worst-case scenario, but since the overall usage level is still fairly low, the systems coexist without causing catastrophic problems, a testament to the soundness of the 802.11 design. We used Compaq iPaqs, with all but the Fluke WaveRunner running Pocket PC 2002.
To get another perspective on needs in a more controlled environment, we spent time demonstrating the products to and gathering input from the network manager of a local high school, which has more than 60 APs installed and serves more than 1,000 students' notebook computers. In this environment, performance, rather than security, is the key consideration, though we were somewhat surprised that the school did not have any advanced tools of this sort in place.
Because all the products differed somewhat in functionality, we could not develop the typical systematic performance tests we use in other tests of WLAN infrastructure equipment. We did, however, develop some clear impressions of the limitations. Like all WLAN analyzers, these products scan 11 to 14 22-MHz radio channels, but because they can capture data on only one channel at a time, you cannot gather all data on the network at any given moment in time. Some higher-end notebook wireless analyzers can monitor multiple channels simultaneously, but you must sacrifice portability. Fortunately, many of the performance and security problems can be identified without the need to capture and analyze every packet.