I am getting this weird issue on my laptop:
When I'm very close to the wifi-router I get excellent speeds. Moving even 10 feet away from the router brings my download speed down from 100 MBps on speedtest.net to 88kbps and a ping latency from 19ms to 1077ms.
What's even weirder is, that, when I use the internet over ubuntu on that laptop, it starts to interfere with the wifi for my other laptop (a mid-2012 unibody MacbookPro) to the point that my macbook pro loses internet connectivity. I also tried turning off my macbook and tested the internet connection over ubuntu, that does not help either.
I tried using 3rd party drivers from the Software & Updates window, to no avail.
I know this is not a hardware issue since I have the laptop on dual-boot with windows and I get more or less the same internet speeds near and equally far away from the router.