How can I prevent iwconfig power management from being turned on?

Type iwconfig and look at the output. You should see the name of your chip-set as well as the whether power management is off or on. If it doesn't say, it is probably off.

To turn off power management, go to /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf and you will see

[connection]
wifi.powersave = 3

Change the 3 to a 2 and reboot.

Then run iwconfig and if it worked you should see Power Management:off.

Source: https://sites.google.com/site/easylinuxtipsproject/internet

Wireless powermanagement is run by a hook in pm-utils. You can turn it off in any of the following way:

Create a file in /etc/pm/config.d. I have named it blacklist:

gksu gedit /etc/pm/config.d/blacklist

and inside the file keep:

HOOK_BLACKLIST="wireless"

If you want to disable any other hooks, default hooks are located at /usr/lib/pm-utils/power.d/.

OR

You can just create an empty hook in either /etc/pm/sleep.d or /etc/pm/power.d. See which one works for you. i.e.

Just do

sudo touch /etc/pm/sleep.d/wireless

OR

sudo touch /etc/pm/power.d/wireless

If turning off power management for your wireless interface speeds up internet like this:

sudo iwconfig wlan0 power off

Than to make it permanent run command as follows:

1. cd /etc/pm/power.d

2. sudo gedit wifi_pwr_off

   This will open an empty file, copy the code below into it:

   #!/bin/sh 
   /sbin/iwconfig wlan0 power off
   

3. Save the file, remember to

   sudo chmod +x wifi_pwr_off
   

   and restart.