01
Survey the air around you
A scanner shows every network, its channel and its signal. In a block of flats the 2.4 GHz band is usually a solid wall of overlapping networks, which is why it fails first.
Use **5 GHz** for anything that needs throughput, keep **80 MHz** width unless the flat is crowded, and pick a channel after looking at what the neighbours use.
Requirements
- Router admin access
- A Wi-Fi analyser app
- Five minutes
Instructions
02
Put throughput on 5 GHz
Move phones, TVs and the main PC to the 5 GHz band. It has more channels, less interference and shorter range, which in a flat is a feature rather than a limitation.
03
Use channels 1, 6 or 11 on 2.4 GHz
Those three do not overlap in the 2.4 GHz plan. Any other channel sits on top of two others and loses throughput to retransmits even when the signal looks fine.
2.4 GHz: 1 / 6 / 11 onlytipPick the one with the fewest access points on it, not the one with the least signal strength.
04
Choose width by density
80 MHz on 5 GHz doubles the throughput and also doubles the chance of sharing with a neighbour. In a dense building 40 MHz is often the faster choice in practice.
5 GHz width: 80 MHz / 40 MHz
05
Separate the bands with clear names
Give 2.4 and 5 GHz different names so a device cannot silently choose the slow one. Band steering works on paper and fails on plenty of devices.
06
Test after the change
Measure throughput and latency in the same spot before and after. Channel changes that feel faster are often the same speed with a different retry rate.
Common issues
5 GHz drops in the next room
Higher frequencies penetrate walls worse. Keep a 2.4 GHz network for coverage and use 5 GHz where the device stays put.
Speed halves at random
The router fell back to a narrower width after radar detection. Check the event log on the router; DFS channels do this by design.
Everything is slow at the same time each evening
Neighbour traffic, not your settings. Switch to a less used channel and test again at that hour.
The laptop prefers the 2.4 GHz network
Both networks still share a name, or the driver prefers the stronger signal. Rename them and forget the old profile.
Frequently asked
Is a wider channel always faster?
Only when the spectrum is free. At 160 MHz in a city you are sharing with several neighbours.
Should I use auto channel selection?
Fine on a quiet network, unpredictable in a dense one. A fixed channel you tested beats an automatic guess.
How to undo this
Set the router back to its automatic channel and width settings. Client devices rejoin after the SSID disappears for a moment.
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- 2026-10-31First version
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