As we know WIFI can overlap transmission channel with other WIFI nearby our house or work site.
To verify why our WIFI connection is slow or if there are other WIFI that use the same channed I found very useful this utility:
Xirrus Wi-Fi Inspector
Download:
https://s1115638394.t.eloqua.com/e/f2
I take note about this usefule article that give 6 useful WIFI utility
http://www.computerworld.com/s/article/9182863/6_useful_Wi_Fi_tools_for_Windows
