Q. What devices can interfere with a wireless networking signal?
A. Wireless networks operate through radio signals at a frequency of 2.4 gHz, so anything else that produces a signal on the same frequency can cause interference. Microwave ovens, cordless phones, wireless security cameras, baby monitors, and halogen lamps are all examples of devices that may interfere with a wireless network.
Note that the source of the interference may not be in your office. Other wireless networks may exist nearby that are powerful enough to override your signal, and cordless phones and similar equipment are designed to operate over a long range as well. If this is the case, switching your wireless equipment to a different channel may help.
Wireless signals also can be degraded or stopped entirely by certain obstacles between the signal source and the computer. Anything metal - filing cabinets, metal walls, foil-backed insulation - will effectively block a radio signal. Water (like in a water heater or fish tank) or dense building materials can act as impediments. A signal that has to make a lot of turns to reach its destination will not extend as far as one that follows a straight path. Moving the wireless access point to a location clear of obstacles can make a big difference, as can adding additional access points or wireless repeaters.
