Unknown data use in the middle of the night

jefe · ‎01-31-2004

My wife has an iPhone 4 on our family plan. She has a 200 MB plan which she's about to exceed for this month. I'm looking at her data use and trying to figure out where the 200 MB is going.

I notice that every night around 12:30 AM there's data use showing of about 4 MB. That's around 120 MB in a 30 day month and I have no clue what it's for. At that time of night the iPhone is charging, locked, and a few feet away from our wifi access point.

Might anyone have a guess that can be happing at that time every night that's being charged to our data plan, especially since the iPhone is connected to the Net via wifi?

Thanks in advance for any light you can shed.

brainwaver · ‎04-10-2009

If you use the "search" box you will find your answers. There are numerous threads concerning the "phantom data" usage during the night.

jefe wrote:
My wife has an iPhone 4 on our family plan. She has a 200 MB plan which she's about to exceed for this month. I'm looking at her data use and trying to figure out where the 200 MB is going.

I notice that every night around 12:30 AM there's data use showing of about 4 MB. That's around 120 MB in a 30 day month and I have no clue what it's for. At that time of night the iPhone is charging, locked, and a few feet away from our wifi access point.

Might anyone have a guess that can be happing at that time every night that's being charged to our data plan, especially since the iPhone is connected to the Net via wifi?

Thanks in advance for any light you can shed.

jefe · ‎01-31-2004

I guess I wasn't smart enough to search for "phantom data."

Thanks for the lecture. I just read alot of long threads and still haven't seen a conclusive answer to what's going on.

edit: After doing more searching and more reading, I still can't even be sure if the iPhone 4 with IOS 5.01 stays in wifi mode when it's asleep but charging.

sandblaster · ‎08-15-2006

The main thing to realize is that the time shown is not necessarily when the data was downloaded. It can take up to 72 hours for downloads to appear on you usage statistics and often times what you see is an aggregate of multiple downloads. Bottom line the 4mb of downloading you see could have occurred at any time during the previous day.

I am an AT&T employee and the postings on this site are my own and don’t necessarily represent AT&T’s positions, strategies or opinions.

jefe · ‎01-31-2004

Thanks. That's helpful.

That being the case though, if someone finds they're using more data than they think they should be, or more than they're willing to pay for, the system of reporting makes is impossible to tell what's using that data.

How about the issue of whether or not an iPhone 4, with IOS 5, uses cellular data when it's asleep but charging and in range of wifi? Is there a definitive answer to that puzzle?

dwill05 · ‎04-06-2005

Keeping the phone plugged in keeps it connected to wifi, but I think it's been said that there are some functions that use network data even if wifi is available. Do you have the diagnostics turned off?

jefe · ‎01-31-2004

Since turning off wifi when asleep is a battery conservation step, it makes sense that if the phone is charging that shouldn't be necesseary. Yet there seems to be a lot of debate on whether or not wifi stays on when the iPhone is asleep but charging. I can see when the iPhone's MAC address is connected to our wifi AP. I'm going to check that once the iPhone has been asleep for a while to put that question 100% to rest in my own mind.

The diagnostics question is interesting. I've seen diagnostic mentioned alot too but I can't find any such option. Where should I be looking?

Thanks for your input.

edit: Drilling around long enough I just found Diagnostics and Usage. Yes, it is and was turned off.

jefe · ‎01-31-2004

Ok, dwill05, a little more on wifi staying on or shutting down.

My tests conclude you were correct. When the iPhone is charging wifi stays on. I also was able to determine that wifi will also stay on even when the phone isn't charging if cellular data is turned off.

If cellular data is on, wifi is shut off almost immediately when the phone goes to sleep, including if you put it to sleep manually.

Now...if I can just figure out where that data use is going.....

johninsj · ‎07-07-2010

jefe wrote:

Yet there seems to be a lot of debate on whether or not wifi stays on when the iPhone is asleep but charging.

No debate - the wifi stays on. Assuming the wifi access point it is connected to stays up, and the internet connection available through that wifi stays up, and the AC power stays on, the iPhone won't use cellular data if it is connected to wifi, plugged into AC, and is awake or asleep.

If a power fail happens, wifi will drop (since the AP will die, which will drop it on phone...)

If the AP drops the connection, you can use cell data

If your home internet goes down, the phone will fall back to cellular data...

So, yes, generally speaking plugging it in should keep it on Wifi. But bad things can still happen.