Which of the following are common RF interference sources affecting 2.4 GHz WLANs?

• A. Microwave ovens, Bluetooth, cordless phones, neighboring WLANs
• B. Microwave ovens and Bluetooth
• C. Cordless phones and neighboring WLANs
• D. Microwave ovens, cordless phones, Bluetooth only

Answer: (A)

In 2.4 GHz WLANs, interference comes from devices that also operate in the same unlicensed band. Microwave ovens can leak energy into 2.4 GHz when they’re in use, Bluetooth devices constantly hop across the 2.4 GHz spectrum as they pair and communicate, cordless phones that use 2.4 GHz can transmit in the same band, and nearby WLANs can transmit on overlapping channels, causing collisions and slower performance. Because all of these sources are common in homes and offices, the option that lists every one of them best represents real-world interference. The other options miss one or more frequent sources, such as nearby WLANs or cordless phones, so they’re less complete.