There's a lot of snake-oil in the technology world. From gold plated fibre optic cables to anti-radiation phone cases - there are a whole lot of people willing to exploit technical ignorance in return for money.
There's also a lot of misinformation, folklore, and crazy thinking which confuses us when we try to interact with "simple" technology. For example, I was in Waterloo Tube station when I saw this
That's one of the WifI boxes which power Internet access underground. I took a look at the antennae on the box and was shocked at what I saw...
Look! All of them pointing in exactly the same direction! Surely everyone knows that each antenna should be pointing in a different, preferably perpendicular, direction. That way you... err... avoid interference and... stuff...
At this point, my brain gave up on me. I was fairly sure sure that I had been told how to correctly align WiFi aerials... but I had no knowledge to back up this information. I fired up my trusty WiFi Analyzer and took a look at the signals around me.
Actually... that looks pretty good! The clustering is showing the same access point broadcasting multiple SSIDs. I can pick up three distinct networks - probably spaced further down the platform. There is a little bit of interference on channel 1 - and that looks like it's picking up some stray signal from another platform.
So, what's going on? Why is received wisdom so wrong on this matter?
Partly, it's because the science of multiple input multiple output radios is hard.
The ergodic channel capacity of MIMO systems where both the transmitter and the receiver have perfect instantaneous channel state information is
Secondly, your WiFi performance is as much about your physical environment as it is about your technology. If you live in a flat, you don't need those radio waves to travel vertically, if you live in a building with thick walls, there may be nothing you can do to improve performance.
London Underground platforms are fairly benign radio environments. Not a lot of interference down there - compare that to my experience at Mobile World Congress last year:
In a normal urban home, you're likely only to have to deal with half a dozen neighbours trying to cram their WiFi into the same crowded spectrum.
So, given all the variables, and taking in to account all the myths, what should one do?
Seriously, that's it. Unless you have the money to do a detailed electromagnetic survey, really all you can do is try putting your wifi router in different positions, angle the antennae, move your furniture, and see what gets you the fastest and most reliable connection.
And make sure to remove all amethyst crystals from your house, obviously...