Moving your router a few centimeters might seem like an overly obvious fix, but it's backed by complex studies on electromagnetic wave behavior. Jason Cole from Imperial College London explains that the WiFi signal bounces through every room in your home, then settles into a stable pattern. If a coverage hole appears, moving it just a few centimeters can change that pattern and shift the hole entirely.
Personally, I've never had issues with WiFi coverage. My old WRT54G modified with DD-WRT still spits out bytes like it's day one, and my house is small enough that there's no connectivity black hole. Unfortunately, many users aren't so lucky. Simple issues like router placement and room layout turn WiFi into a juggling act. Of course, you could always add repeaters or secondary routers, but that route involves extra cost not everyone can afford. With that in mind, a cheap and simple solution brings us to the oldest trick in the world: move the router until the darn WiFi works throughout the house.
Why does this happen in the first place? Jason Cole from Imperial College London, creator of the WiFi Solver Android app, explains it with a bit of math and electromagnetic theory. In simple terms, the interaction between electromagnetic waves and the plasma in our upper atmosphere is governed by the so-called "Maxwell's equations", first published by James Clerk Maxwell. New revisions to the equations, along with algorithms and modern processing power, let us calculate the flow of electromagnetic waves with something as simple as a smartphone. Needless to say, WiFi prefers open spaces to walls (though some materials are more forgiving than others), but we also encounter the phenomenon of a "standing wave", which appears when reflections of the WiFi signal overlap each other.
In summary: Moving the router just a few centimeters can be enough to optimize signal reach even in the trickiest parts of the house. I understand many people leave their router fixed to the wall, or are limited by wiring, but I think it's better to make a small change in its location before rushing out to buy repeaters.
