WiFi Channelization is Important

Troubleshooting a slow WiFi system in Moncton, New Brunswick today, the first thing I noticed was that most of the AP’s were on the same channel.  Why?  Not understanding I guess is the most likely explanation.  This particular outdoor venue had 8 access points, five of which were on channel 6, one on channel 2 and two on channel 11.


Remember that with 802.11b/g/n on 2 GHz we only have about 50 MHz of spectrum for standard channels, each 20 MHz wide.  Therefore channels 1-6-11 are the only concurrently usable channels without causing interference.  Therefore care must be taken to only reuse channels when you are out of range of other AP’s on that frequency.  For that reason, small cells are always the key to the most efficient WiFi network.  A typical channelization pattern would look this this:


I made the recommendation to the operator, but I am still not sure they believe that the fix could be so simple without upgrading equipment.  Actually an upgrade would be nice because the AP’s are all Senao. I hope you keep channelization in mind when designing WiFi networks.