In short
Usually the router is in the wrong place: too far away, behind too many walls or inside a cabinet. Every reinforced concrete ceiling, every wall with underfloor heating and every radiator in between eats signal. A second access point in the right spot, as mesh or connected by cable, fixes this in most homes. A stronger router almost never does.
What eats the signal
Wi-Fi is radio, and radio is weakened by everything standing between router and device. Distance alone is rarely the problem, in an open hall 30 metres are fine. In a house the obstacles count: a reinforced concrete ceiling roughly halves the signal, a wall with underfloor heating or metal studs does the same, a water heater or aquarium acts like a wall.
Then there are the neighbours. In the 2.4 gigahertz band there are only three channels that do not overlap, and in an apartment building twenty routers transmit on them at once. The 5 gigahertz band is faster and emptier but passes through walls less well. That is why bedroom Wi-Fi is often gone on 5 gigahertz and slow on 2.4 gigahertz.
Step 1: place the router properly
The router belongs in the open, up high and as central as possible in the home. Not in the cabinet, not in the basement, not behind the TV and not next to the radiator. Even one metre higher, on a shelf instead of the floor, noticeably helps in the next room. The socket is often in the hallway in the wrong place, and then a longer cable from the socket to the router helps more than any accessory.
Step 2: measure instead of guessing
Run a speed test on your phone right next to the router and then in the bedroom. If it is already slow next to the router, the line or the router is the issue, not the range. If it is fast next to the router and under a tenth of that in the bedroom, it is the range.
For orientation: high-resolution video streaming needs about 25 megabits per second, a video call 5, home office with cloud documents 10. A bedroom rarely needs more. If 30 megabits arrive there, the problem is solved, even if the line could deliver 250.
Step 3: a second access point
If placement and measurement say the signal does not make the distance, you need a second device that is closer. There are four ways, and they differ more than the packaging suggests.
- Repeater: cheap, plugs into a socket, but halves the speed because it receives and sends on the same band. It belongs halfway, where reception is still good, not in the bedroom itself.
- Mesh: two or three stations that coordinate and hand over the phone between them. One Wi-Fi name for the whole house, no switching. The best solution without cables, from about 150 EUR for a set.
- Powerline: uses the mains wiring as a cable. Works brilliantly in some houses and not at all in others, depending on circuits and the fuse box. Test first, buy with a right of return.
- Network cable plus access point: the most stable solution of all. If a cable can be run to the bedroom, often along the skirting board or through a conduit, the problem is gone for good.
What does not help
Twisting the router antennas, apps that "boost your Wi-Fi" and aluminium foil behind the router: all seen before, none of it helps. A new, more expensive router does not change a concrete ceiling either. It only pays off if the old one is over ten years old or cannot do 5 gigahertz.
Do not switch off the 2.4 gigahertz band to "tidy up" the network. Many smart home devices, printers and older TVs can only use this band and drop off the network.