Keep Wi-Fi on during sleep

[mwake4goten]

I've seen this setting under wifi/advanced. The setting is about the state if the wifi wheb the screen is off and it outlines three conditions during screen off time. One of them is that the wifi should be in always be on , the other is that it should only stay on if the phone is charging and the final one is that it should never be on during sleep mode.

Some people recommend that it should be on always and have mentioned that the phone will use mobile data if the wifi goes to sleep. But what if you've set your mobile data to be off? The phone shouldn't be able to access mobile data if you've instructed it to be off. Or does the wifi setting 'force' the mobile data to switch on regardless of users instruction.

 

[cbreze]

I noticed that setting also but thought it to be a head scratcher as far as what do I need that for. I leave my wifi on 24/7 and it uses no cellular data as far as I can tell. Anything coming in over nite is over wifi. I don't see any logical reason to mess with turning it off or turning off cellular data either. I keep it simple. Do not disturb keeps everything that's going on at night quiet then when I get up the next day it's all there for me to view.
Why not just leave it on and set DND to control any alerts/noises?

 

[tim_hobbs]

I've always assumed it's a battery saving option, but don't use it either. If you set Wi-Fi to turn off when the phone sleeps it would save battery overnight for sure as long as mobile data is off too ( depending on signal strength ).

Data will not be switched on if you choose this setting in Wi-Fi advanced but also have it switched off in settings btw. Your Wi-Fi and mobile data will not work

 

[mwake4goten]

Well I've had the setting on for 24 hours and I can report that it definitely has improved the battery life of this phone. My phone would sometimes drain at best at a rate of 0.5 to 1% an hour... Now with WiFi set to sleep my phone dischsrges at a rate of 0.1 to 0.3% an hour. So obviously much better. Admittedly I don't get email, social network and instant messaging updates as soon as they happen but I check my phone manually so it doesn't matter that I don't get instant updates. Win win!