Raspberry Pi 3 wifi goes to sleep - Power Management (SOLVED)

Raspberry Pi 3, wifi goes to sleep?

How do I disable suspend mode?

I'm facing a similar issue to this one, How do I disable suspend mode?, except I have a Raspberry Pi 3 and am running OpenELEC 6.0.3. When I leave it on without using it for awhile, I can no longer ssh to it or connect to it via samba. I have to use it use again and then I'm able to connect to it (although occasionally I have to reboot in order to be able to ssh to it for some reason).
Is the wifi going into sleep mode when there is no traffic? How can I disable it on the Pi 3?

How can I disable it on the Pi 3?

• Edit interfaces using a simple editor called nano. Enter:
  

  sudo nano /etc/network/interfaces

To stop your wifi from go to sleep after idle for awhile, you need to disable its power management.
Edit file /etc/network/interfaces
Assume you Pi connect to network through wlan0. Add new line with wireless-power off right BELOW the line iface wlan0 inet manual
Save and reboot your Pi
run iwconfig now you should see Power Management:off

upgrade to "next" firmware branch:

sudo BRANCH=next rpi-update

mine is now kernel 4.4.3 and firmware 41f8b4812ad653abf321b8c54cb4bee57ebdb129 and now accepts the power off command. My connection was constantly dropping, this appears to have sorted it!

For me, although iwconfig wlan0 power off doesn't work, the alternative iw dev wlan0 set power_save off does work.
So I've commented-out wireless-power off in /etc/network/interfaces, and replaced by:

allow-hotplug wlan0
iface wlan0 inet manual
#   wireless-power off
    post-up iw dev $IFACE set power_save off

Also, added this line: sudo iwconfig wlan0 power off    to     /etc/rc.local - to keep power management off after reboot.

sudo nano /etc/rc.local

more examples :

https://www.mathworks.com/help/supportpkg/raspberrypi/ug/getting-the-raspberry_pi-ip-address.html?requestedDomain=www.mathworks.com

Pi 3 WiFi unstable - Raspberry Pi - OSMC Forums
https://discourse.osmc.tv/t/pi-3-wifi-unstable/14171