iwconfig

iwconfig is used to configure wireless network interfaces.
It is similar to ipconfig,, but is dedicated to the wireless interfaces.

_Turning off power management _
Edit this file:
/etc/NEtworkManager/conf.d/default-wifi-powersave-on.conf

Change:
[connection]
wifi.powersave=3
to 2.

Other possible values:
NM_SETTING_WIRELESS_POWERSAVE_DEFAULT (0): use the default value
NM_SETTING_WIRELESS_POWERSAVE_IGNORE (1): don't touch existing setting
NM_SETTING_WIRELESS_POWERSAVE_DISABLE (2): disable powersave
NM_SETTING_WIRELESS_POWERSAVE_ENABLE (3): enable powersave