Does iOS use 3G when screen is off (sleeping)?

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Batman

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#111558 7-Nov-2012 12:29

I noticed my wife's iphone always shows 3G for about 0.2467 seconds when i turn the screen on and then the wifi icon appears ... googling seems to suggest wifi goes off when sleeping and hence all push notifications must be via 3G?

I guess her data use has never been an issue but if this is true I am with Android for life!

I know you can turn off cellular data at home but I have better things to use my memory brain cells for ...

johnr

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#713472 7-Nov-2012 12:33

0.2467 seconds how did you get this figure?

Dairyxox

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#713474 7-Nov-2012 12:36

Mine does this too..

Its a highly accurate guesstimation JohnR. Basically you see it for a fraction of a second before the wifi symbol takes its place.

The annoying thing is when the Mrs is trying to facetime call me. It only works over wifi, but when the screen is off, the phone logs off wifi, onto cellular, so she cant call me.

Edit: more info, I notice if I turn all cellular data off, then there is no symbol, then it quickly shows wifi when the screen is unlocked, ill try take a video of this later if necessary. I'm on Vodafone, not that it should matter, because it seems to be a phone firmware/wifi issue. Ive got the orcon genius lite router. iPhone 4 iOS 6.0

gcorgnet

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#713478 7-Nov-2012 12:46

Hi,

This does sound like a battery-saving feature that disables the wifi while the phone is asleep.

I might be wrong but I think my Android phone used to do this at some point.

There my be a setting to prevent this...

Guillaume

RunningMan

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#713479 7-Nov-2012 12:47

AFAIK the Wifi shuts down with sleep to use less power.

There are two workarounds:

1) Disable cellular data so it keeps a data connection via Wifi

2) Plug the charger in

Dairyxox

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#713485 7-Nov-2012 13:04

Disabling Cellular Data doesn't help, the phone still drops wifi when asleep.
It probably is a battery saving feature as suggested.

Its probably not an issue, except missing push notifications (unless its smart and logs back into wifi for 10 seconds every 5 minutes for example).

Missing facetime calls is my particular issue with this. However I think my facetime thing might be a different issue, because it doesnt seem to work with my mobile number, even when the phone is 'awake' & connected. It does however work when people facetime my apple id. This makes me think my issue is the SMS system apple uses to initialise a facetime calls over mobile number. (I suspect if the SMS thing was working, the phone would receive the initialisation txt while 'asleep' and quickly wake up the WIFI.)

Sorry if I'm hijacking your thread, it just seemed related. I definitely notice the same thing, Just saying it might not really be an issue.

Batman

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#713558 7-Nov-2012 15:23

the problem is ... apple is cheating me of 3G data when i'm supposed to be next to a wifi connection ... i am told with certain iOS disabling cellular data will keep wifi connected but try telling my wife (or anyone inc me) to do that every single time you leave and approach wifi!

Dairyxox

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#713591 7-Nov-2012 16:12

I guess you should check your mobile data usage. If its only, say, 2MB a month of 3G data for this then it doesn't really matter and isn't a big deal.

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Batman

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#714082 8-Nov-2012 11:33

yeah i have to admit data overuse has never been a problem ... but for the forseeable future ... wondering if certain apps, certain cloud push/pull, etc could cause data $$$ ...

perhaps it activates a packet via 3G and then switches to wifi and downloads? is that how it explains why i don't see data overuse (wife pushes every known communication app on the planet)

Mizon

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#720975 21-Nov-2012 21:13

So how does the iPhone sync with iTunes over wifi even when sleeping?
I suspect it is always connected, it just takes a moment to show the signal strength icon.

RunningMan

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#720980 21-Nov-2012 21:25

Easy way to test: turn off cell data, put the phone to sleep, then check your WiFi AP to see if the phone is still connected.