Wi-Fi Channels and Frequencies

A Wi-Fi Network uses radio waves and antennas to communicate.  A radio wave is transmitted on a radio antenna at a specific radio frequency.  The US federal government has defined frequency bands that are allowed to be used by Wi-Fi equipment in the US.  The IEEE 802.11 protocol specifies how a Wi-Fi Network operates using these bands.  This protocol sub-divides a frequency band into channels, similar to radio and TV channels.  Each Wi-Fi channel overlaps a few of its neighboring channels and potential causes electromagnetic interference.  This interference must be managed by the Wireless Access Point ("WAP").  

Each Wi-Fi Network SSID is assigned to a channel as a mechanism for managing potential interference.  WAPs have a feature (that is turned on by default) that allows the channel to be automatically selected, but it can always be manually overridden.  Wi-Fi channel saturation happens when too many WAPs have an SSID operating on the same channel and are physically too close together.  This causes interference which in turn causes network slowness and network disconnects.

Any SSID from any WAP will conflict if it is on the same channel.  The name of the SSID does not prevent this interference from happening.  In fact, WAP that are broadcasting the same SSID should be on different channels to prevent interference.  There are three channels (1, 6, 11) that do not overlap and should be used effectively for channel management by WAP that are located physically close to each other. 

Please see For Dummies for more information.

Please see Wikipedia for more information on WLAN Channels

Please see Wikipedia for more information on IEEE 802.11

Please see Wikipedia for more information on Radio Wave

Please see Wikipedia for more information on Electromagnetic Interference

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