Q: What tools should I use to detect interference to my Wi-Fi system?
A: Wi-Fi interference can be a nightmare, resulting in dropped connections, lowered bandwidth, unpredictable performance, and a host of other problems. Finding it with a spectrum analyzer is incredibly easy, but in most cases not financially practical.
Most IT departments don't need to spend five figures on a true radio frequency (RF) spectrum analyzer. The best bet is to create the device that we dubbed the IT Wi-Fi Tool (ITWiT). We make the ITWiT from surplus components and inexpensive off-the-shelf products. Assuming you're seeing interference in the 2.4GHz band (channels 1-14), the parts list is:
- A surplus laptop running Windows XP or later
- A mini-PCI or USB Wi-Fi card that accepts external antennas
- One or two directional 2.4GHz antennas (optional but useful)
- A USB spectrum analyzer, such as Wi-Spy
- A USB GPS receiver
The ITWiT makes finding interference sources a breeze. You simply fire up the device, start the software, and follow the software indicators until you're literally standing next to the interference source.