Tips on Planning around Interference

Besides materials and objects that physically interfere with radio signals, there are sources of radio frequency (RF) signals that operate on the 2.4 GHz band and can interfere with the signal of your WLAN. This is because the 2.4 GHz band is "unlic

ensed" and manufacturers are free to develop wireless products that operate in this range. Whether this interference is intermittent or regular, it can degrade performance to a point where you wonder why you even bothered to install Wi-Fi. Some sources of RF interference include:

Cordless phones and headsets

- Wireless stereo speakers

- Walkie-talkies

- Wireless cameras (security or home monitoring type)

- Wireless intercom units

- Microwave ovens

The easiest way to deal with this sort of interference is to avoid buying consumer electronics that share the same frequency with your WLAN. Manufacturers shield microwave ovens to prevent most signal leakage but the signal can even leak through the power cord at significant strength to cause problems. This should not pose a significant problem as long as you can plan to use the microwave around important network tasks (such as downloading large files). You also can position your APs to reduce the likelihood of the microwave causing problems

If you have a 2.4 GHz cordless phone, you may notice significant degradation in network performance whenever someone is talking on the phone. The typical cordless handset puts out over five times as much power as a wireless NIC. The same goes for wireless stereo speakers, walkie-talkies, and other devices; they all tend to put out significantly more power than Wi-Fi products.

If you already own a number of these devices, other than replacing all of them, your options are limited. If you haven't invested in your Wi-Fi gear yet, you can invest in 802.11a devices that operate in the 5 GHz frequency band. Electronic devices operating at 2.4 GHz won't interfere with 802.11a Wi-Fi gear.

Of course, even if you eliminate these sources of interference from your home, you may still run into occasional problems. If you live in an apartment, condominium, or townhouse, your neighbors may have one or more of these devices. The RF interference travels through walls and could be strong enough to cause problems. In this case, the best solution is a combination of diplomacy and experimenting with the positions of your clients and APs to minimize the disruption.

After you've determined what you are going to network, which standard you are going to use, and where everything will be located, you can get down to the task of choosing the actual hardware that you will install to make your wireless dream a reality.