What are the 2.4 GHz and 5 GHz Wi-Fi bands?

What it is

A band is a slice of radio spectrum divided into channels. An access point picks a channel in each band it supports, and every device on that channel shares the same airtime.

• 2.4 GHz: reaches farther and passes through walls better, but it is slower and crowded. In the US only three channels (1, 6 and 11) do not overlap, and microwave ovens, Bluetooth devices and neighboring networks all share the space.
• 5 GHz: faster, with many more channels, so it is far less crowded. The signal fades sooner with distance and through walls.
• 6 GHz: a newer band that only newer devices can use. It has plenty of room, and its reach is a little shorter than 5 GHz.

The 6 GHz band arrived with the E versions of Wi-Fi 6 equipment.

Why it matters to a business

• Access point placement: 5 GHz covers less distance, so a building usually needs more access points, closer together, than 2.4 GHz alone would suggest.
• Older devices: many printers, scanners, sensors and badge readers only speak 2.4 GHz. They need a signal there, so the band cannot simply be switched off.
• Dropped calls: video calls that stutter in a busy office often trace to a congested 2.4 GHz channel, not to the internet connection.
• Neighbors and gadgets: in a shared building you also hear other tenants. Bluetooth devices add to the noise on 2.4 GHz.

How this shows up in our work

Our Wi-Fi installs use Ubiquiti UniFi access points, positioned from a floor plan so that 5 GHz coverage is planned room by room. Older 2.4 GHz devices can sit on their own network, separated from staff and guest networks with VLANs.

Learn more

• List of WLAN channels on WikipediaTables of every channel in each band, useful when checking which ones overlap.
• IEEE 802.11 on WikipediaBackground on the Wi-Fi standard family and which bands each version uses.
• Wi-Fi AllianceThe industry group behind Wi-Fi certification, with plain explanations for buyers.