Wireless spectrum analysis typically falls into two camps: free open-source software such as NetStumbler or Kismet, and ultrapricey hardware-software combo products like the Grasshopper. This leaves a huge gap between those who have the time to play with open-source stuff and those who have the budget to play with proprietary tools.
MetaGeek is charging head-first into this gap with its Wi-Spy product line of inexpensive (sub-$800) spectrum analysis products. In April, eWEEK reviewed MetaGeek Wi-Spy 2.4x, an earlier product that only covered the 2.4GHz band. The Wi-Spy DBx retains the power and ease of use of its predecessor while adding improved software and coverage for the 5GHz band.
The vast majority of businesses-and homes-are already using a WLAN or are planning on installing a one. With so many networks and devices out there, the airwaves are getting jammed. Organizations need to perform site surveys to plan a WLAN and then regularly scan the airwaves to look for unauthorized or rogue access points. In addition, there are many sources of interference, such as microwaves and some cordless phones, which can degrade performance or outright block WLAN traffic. Wireless administrators are constantly on the lookout for new ways to solve these problems.
Wi-Spy DBx is a small USB device that can scan the radio frequency range from 2.400GHz to 2.495GHz and 5.170GHz to 5.815GHz (complete coverage of 802.11a/n), with a resolution of 328KHz. It can detect signals in the amplitude range of -115 dBm to -6.5 dBm with a resolution of 0.5 dBm. The Chanalyzer visualization software includes a device signature library that allows a user to determine what is creating interference.
The first thing I noticed about Wi-Spy DBx is that it uses an industry-standard antenna connector (RP-SMA) that enhances the flexibility of the device because the antenna can be replaced with another for greater directionality and gain. For example, by using a series of adapters, I was able to connect an 18 dBi omnidirectional antenna, which allowed me to pick up dozens of WLANs in my New York neighborhood. I ultimately decided that the best way to troubleshoot with the Wi-Spy DBx was to start with the monster antenna to do a wide scan and then move to the smaller supplied antenna to pinpoint interference.