2.4 and 5 GHz, channels and width: how to set up Wi-Fi properly

Published 2026-11-03 · 6 min read · By the Alian Digital team

Wi-Fi works in an airspace you share with your neighbours. The right channels and width often give more than a more expensive router.

2.4 GHz versus 5 GHz

• 2.4 GHz: passes walls better but is slower and very crowded (neighbours, microwaves, Bluetooth).
• 5 GHz: faster and cleaner but passes obstacles worse and has a shorter range.
• In a house with several points 5 GHz carries the main speed while 2.4 GHz stays for far rooms and simple devices.

Channels on 2.4 GHz

Only three channels are really independent here: 1, 6 and 11 (20 MHz wide). If your network sits on channel 3 it interferes with two neighbouring channels at once. Do not enable wide 40 MHz on 2.4 GHz in dense housing: it increases interference.

Channels and width on 5 GHz

There are more channels, so you can use 40 or 80 MHz if it is quiet around. In dense housing 40 MHz or less is wiser: stability matters more than theoretical speed. Some 5 GHz channels use DFS: the router must vacate the channel if it detects radar, so the connection can briefly drop.

"Auto" or manual

"Auto" is convenient but often changes channels at a bad moment or picks too wide a width. With several points it is better to assign channels manually so that neighbouring points do not match.

Roaming between points

The phone decides itself when to switch to another point and often clings to a distant one too long. Standards 802.11k/v/r and the same network name and password on all points help. Some settings (minimum signal level to connect) should be changed carefully.

What to leave alone

• Transmit power at maximum: it does not make the network better, only louder for neighbours and for the devices themselves.
• Old compatibility modes (802.11b) unless you need very old devices.
• Merged network names for 2.4 and 5 GHz when not needed: sometimes separate names help you see what a device is connected to.