If you are referring to the WiFi sleeping after a given period, this sleep can be disabled using the Netgear app (Android or iOS). The feature is in the Settings section under the WiFi heading - you should find the "Sleep" setting there - set it to "Disabled". This setting isn't included in the browser-based interface for the MR1100 (at least not in my version, which is from the mobile network provider EE in the UK).

However, the Ethernet port also sleeps after a period of no activity. This can be woken up by tapping the power button once - it wakes after a few seconds.

I have my MR1100 set up as my main household router - the Ethernet port is connected to a Gigabit Ethernet switch and I have 2 dual band WiFi access points also connected into the switch. The fact that the Ethernet port goes to sleep is frustrating because devices attempting to connect by WiFi to one of the access points don't get an IP address allocated to them by the DHCP on the MR1100. I have to tap the power button on the MR1100 if it's asleep and then the devices get their IP addresses.

One of the Netgear moderators said there will be a new firmware release in Feb that will allow the Ethernet port to be set permanently on. There will also be the option to turn on the Ethernet port by default after a reboot - at the moment the Ethernet port is turned off by default after a reboot. Here's the post from the Netgear moderator: Nighthawk-M1-Ethernet-Port-Timeout