Who's sniffing your wireless network?

No, it isn't cheap. But in this case, you get what you pay for. AirMagnet's new Spectrum Analyzer costs about $3,500. In return, the product gives you invaluable tools to protect your wireless network.

Even if nobody is trying to hack into your network — and just because you aren't paranoid doesn't mean somebody isn't after you — Spectrum Analyzer helps you locate sources of interference such as microwave ovens, portable phones and Bluetooth devices that might be hampering your 802.11 wireless communications.

Spectrum Analyzer couldn't be easier to install and get running. Once I loaded the software, it was simply a matter of popping the PC Card into my laptop computer and launching the tool. You can use an optional external or directional antenna to increase your range.

The interface is easy to navigate. A click lets you change the main window's display from a real-time report of spectrum activity to a summary of channel characteristics.

You can also zoom in on a specific source of interference and record its activity. As you move around your wireless local-area network (WLAN) space, this feature allows you to locate the source of the interference.

You may not, however, have to do anything because Spectrum Analyzer does a decent job of reporting common sources of interference. As soon as I booted up the program, for example, it told me that a Panasonic portable phone, including the model number, was operating in the scanned frequency range.

Finally, be aware that Spectrum Analyzer is only part of the solution for protecting your WLAN. It doesn't, for example, identify 802.11 wireless clients or report the numbers of access points using a specific channel. If you want that capability, you'll need a tool such as AirMagnet's Laptop Analyzer.