Referencing Wi-Fi Channel Numbers Correctly

It occurred to me today that many people still use the old Wi-Fi terminology for referencing wide channel numbers in the 5 GHz band. Since channel numbering changed with 802.11ac, I thought it might be helpful to get everyone on the same page when we're talking about channel number.

So here is a quick reference guide to referencing the 5 GHz Wi-Fi channels.

Wide channel numbering changed with 802.11ac:

  • 802.11n Channels (the "old" way)
    • One 20 MHz primary channel, with a channel extension above or below
    • 40 MHz Example: Channel 36, +1
    • 40 MHz Example: Channel 40, -1
    • 40 MHz Example: Channel 36+40
    • This terminology should no longer be used

  • 802.11ac Channels (the "new" way)
    • Reference the center channel frequency for the entire 40/80/160 MHz wide channel
    • Designate one 20 MHz portion of the wide channel as the Primary 20 MHz
    • 40 MHz Example: Channel 38 with Primary 20 MHz channel 36
    • 80 MHz Example: Channel 155 with Primary 20 MHz channel 149
    • 160 MHz Example: Channel 50 with Primary 20 MHz channel 44

Andrew von Nagy