In plain words
Wi-Fi is a conversation out loud in a room. The further away you are, the more walls there are, and the more other conversations are held on the same frequency, the less you understand each other. The assistant first checks whether the problem really comes from Wi-Fi, then which cause: distance, congestion, hardware or settings.
The decisive test: the cable
Before blaming Wi-Fi, the assistant asks for a measurement over an Ethernet cable directly on the router. If the speed is poor even by cable, Wi-Fi is not to blame: it is the line, the router or the plan. This single test saves hours of pointless tweaking.
The three bands in brief
| Band | Range | Speed | Congestion |
|---|---|---|---|
| 2.4 GHz | The longest, goes through walls better | Low | Very high: three or four non-overlapping channels depending on the country (1, 6, 11, or 1, 5, 9, 13 in Europe), Bluetooth, microwaves |
| 5 GHz | Medium | High | Moderate; some channels subject to radar detection (DFS) |
| 6 GHz (Wi-Fi 6E and 7) | The shortest | Very high | Low: many free channels |
The best improvement
To cover a large home, an extra access point connected by cable always beats a wireless repeater. Without a cable, a mesh system with a dedicated link between units is the most reliable solution.
If you have no internet at all, use the "I've lost internet access" assistant instead.