Can 802.11ac be used on the 2.4 GHz band?

• A. Yes
• B. No
• C. Only with dual-band AP
• D. Only on a specific frequency

Answer: (B)

802.11ac is meant for the 5 GHz spectrum. It achieves its speed gains by using wider channels (80 or 160 MHz), along with higher-order modulation and improved MIMO, which require more available spectrum than 2.4 GHz provides. The 2.4 GHz band has limited bandwidth and only a few non-overlapping 20 MHz channels, making those wide channels and the accompanying modulation schemes impractical. As a result, 802.11ac radios operate on 5 GHz, even in dual-band devices that also support 2.4 GHz with older standards. So, 802.11ac cannot be used on the 2.4 GHz band.