Keith Parsons of Wireless LAN Professionals comments:
About 5GHz channel allocations…
“Wireless on 5GHz isn’t new, so you may be wondering why DFS is suddenly becoming an issue. The new challenge stems from one of the mechanisms that enables 802.11ac’s faster speeds: its broader channel widths. Earlier Wi-Fi standards used 20 MHz- and 40 MHz-wide channels. 802.11ac allows 40 MHz-wide channels, and its real speed emerges when using 80 MHz-wide channels. The 11ac specification also outlines 160 MHz-wide channels, but at this point it’s a theoretical implementation and not on the roadmap for most vendors.”
Great resource from Keith on the 5GHz channels. There’s a few more than 3 out there!
Read more at: 5GHz Channel Allocations – WLAN Pro Resource Tool