RF Interference Survey
As mentioned earlier, you really need a spectrum analyzer to actually measure the RF energy from non Wi-Fi sources. Even though you can buy the AirSleuth-Lite for under $100, that might still be more than you're willing to spend. But you can do a simple RF Interference survey by simply taking an inventory of devices that can cause Wi-Fi interference.
Updated 6/25/2009MetaGeek has brought back a $99 2.4 GHz spectrum analyzer. The Wi-Spy 2.4i is essentially the same as the original Wi-Spy, but with newer Chanalyzer Lite software. It's a great bargain!
Take a look around your home for the following devices:
- Microwave ovens
- 2.4 or 5.8 GHz cordless phones
- Baby monitors
- Bluetooth headsets, keyboards, mice, etc.
If you have any of these devices, you can do a simple experiment to see if they are causing problems. Place your wireless notebook in the location where you usually have problems, or go to a troublesome wireless-connected desktop computer. Now, turn each device on—one at a time— and see if you have the problem that you tend to have in that location. (Make sure you put a cup of water or something else in the microwave before running it so that you won't damage it.)
You can also try running a long continuous ping, transfer a large file or watch a video while turning on the devices. If you experience problems, then you may have found a source of your wireless woes. Unfortunately, the most effective fix for RF interference is to eliminate the interference itself, which may be costly, inconvenient or not possible.
Site surveys are an important step to solving wireless networking problems because they provide important information to guide you in solving the right problems. Some of the fixes can be simple, which I hope is the case for you. In our next installment, we'll begin to describe how to improve wireless coverage.