Q: Unknown data usage early morning

Just to let you know my wife's phone in Australia using Telstra is also exhibiting large data usage in the night. Push is off and no Safari windows open. Yesterday the phone managed to use 150MB without any usage from its owner!

First up: Sorry about my English, but I'm swiss....
A few days ago I received the monthly Bill by my swiss provider(sunrise) My mobile data exploded from an average of 100-200Mb/Month(Dec.2008 to April 2010) to around 1.3 GB im May 2010. There were data transfers when I was asleep, at work(yep, WiFi there) and at home (WiFi as well). What's odd is the fact that 2/3 of all data beeing sent/received happened between 06.00 and 12.00. That would be between Midnight and 6AM in the US.(New York time, "EST" right?)
I was really upset by my service provider, getting no support what so ever. All they said was that their data shows that my iPhone went online and all data was charged properly...
Now, after reading (almost :-)) every response to this post I honestly think it's not the Mobile provider. It must be the OS of the iPhone or an App... ......It's just strange....

Ok, so my iPhone 3GS was sold, and I'm now using an iPhone 4.

The mysterious Data usage transactions have ceased. Whatever the iPhone was doing over the Cell network it is now no longer doing or it is doing it over WiFi.

Also, after checking my Bill for last month, even though the online site shows these mysterious outgoing data usage events, as best I could tell, we are not being charged for them.

Kenny

Perhaps a change in the iOS 4 software?

I think Jobs or somebody at Apple said that iOS4 would favor WiFi over Cell while asleep.

Perhaps somebody with a 3GS and iOS4 can verify that the data accesses have stopped?

Kenny

I upgraded 5 days ago to iOS 4, and I still see large data transfers between 2 AM an 3 AM

Well since updating to my iPhone 4 using 4.0 I went under the Network settings turned off the 3G and cell data at night and no data being transferred. When I turn it on during the day the activity starts up again. When both are off I can still make/receive calls.

Thinking about my earlier report that there was a 150MB use, this shows up on the total usage but the day to day split seems to have stopped on 26th with no reports since.

The only logical download of that magnitude would have to be the iPhone OS upgrade.

But this was done with both the phone and the computer on our home wifi network. How come it shows on the phone data usage unless somehow the iPhone is tethering and has taken over from the wifi?? Tethering is off for this phone.

Anyway I've now put the sim card in an unlocked 3G to see if the large inexplicable downloads continue or if they are caused by the 3GS phone.

Wow, so much lack of clue in this topic.

First, let me spell this out simply for you all:

*Your phone IS NOT TRANSMITTING A BULK OF DATA DURING THE NIGHT.* Especially not tens of megabytes-worth. Obviously if you have fetch mail set, it'll do that every X minutes and it'll keep a connection open for push and such as well, but nothing bulky. Apart from all this, transmitting 300MB (as I've seen someone mention) over 3G takes several hours.

What you are seeing is AT&T (or whatever other carrier) billing you for a daily session. If you have push enabled, your phone keeps open a connection to your carrier's data network +all the time+.

Carriers normally bill data usage per session. So whenever your phone opens the connection, transmits some data (let's say 100KB), and closes the connection, the carrier will bill you for 100KB. But if you have push enabled, it never closes the connection unless it actually loses the connection to the cell network. This would happen if you turn off the phone/run out of battery (obviously), turn on airplane more, go somewhere without wireless coverage, etc.

As mentioned in this thread, people who've been taking flights (and thus turned off their phones) have seen billing lines corresponding roughly to the times they were up in the air. As I said, with push enabled, the phone usually keeps its connection up forever, so there's no session ending to bill at. So the carrier picks a time to bill the session. I suspect this might involves closing said connection, so they do this at 2 AM so it disturbs as little as possible. If that is the case (I can not say for sure) and you were to keep track of the phone's IP address, you would probably see it change right at the time mentioned in the billing line.

My carrier, Vodafone, also bills me per session. They just happen to be exact about billing open sessions (whereas AT&T is a bit more sloppy). They are billed at midnight exactly. Here's a picture of one of the pages of the data part of my phone bill. It's in dutch but should speak for itself: http://www.cyberhq.nl/~marco/vodafone.png (Don't ask about the third column-- I have no clue myself and no one else appears to know either.) A good example is the 4th of May. You can see the first line on that date being at midnight exactly-- this is the previous day's usage for the session still open at that point in time. Then at 15:30-ish, another charge appears. Apparently my phone lost the connection or was restarted at that point. Then at midnight exactly (billed on the 5th of May), I'm charged for a second time. I use my phone multiple times every day, and my phone checks e-mail every 30 minutes using fetch. Notice a lack of billing every 30 minutes. This is because I do have push enabled for other things, so the connection is left open.

As for 3G usage while wi-fi is available-- the phone must keep open connections to certain services. Notably push services. These continue to use the cell network even if wifi is available. Anything else at that point, however (music streaming, app downloading, web browsing) does use wifi.

I hope this issue can be put to rest-- nothing nefarious is going on.

By the way Cirrus330 right above me: iPhoneOS updates are around 250MB. Your 150MB is just you using the internet.

ok so with does My T-Mobile and the iPhone say different data usage is my question?

This makes absolutely no sense at all. I know T-Mobile's billing is just fine, so what's up with the random data sessions even now that i have auto-fetch/push notifications off?

T-Mobile's log:

"DATA SERVICE CHARGES"

Date,Time,Megabytes
"06/30/10","01:44 AM","9.4062"
"06/30/10","12:02 AM","0.4609"
"06/29/10","11:57 PM","2.8876"
"06/29/10","11:14 PM","0.1416"
"06/29/10","09:30 PM","2.4238"
"06/29/10","07:30 PM","0.2412"
"06/29/10","05:30 PM","0.1816"
"06/29/10","03:30 PM","0.5351"
"06/29/10","01:30 PM","0.3154"
"06/29/10","01:17 PM","0.0585"
"06/29/10","11:52 AM","0.3281"
"06/29/10","11:36 AM","0.0556"
"06/29/10","11:00 AM","0.1933"
"06/29/10","10:40 AM","0.041"
"06/29/10","10:14 AM","0.0986"
"06/29/10","09:43 AM","0.0302"
"06/29/10","08:13 AM","0.1757"
"06/29/10","07:10 AM","0.1689"
"06/29/10","06:51 AM","0.0322"
"06/29/10","06:22 AM","0.0576"
"06/29/10","05:48 AM","0.0361"
"06/29/10","04:08 AM","0.1591"
"06/29/10","02:25 AM","0.1699"
"06/29/10","12:25 AM","0.1425"
"06/29/10","12:05 AM","0.038"
"06/28/10","10:55 PM","0.0761"
"06/28/10","08:55 PM","0.3984"
"06/28/10","07:22 PM","0.1621"
"06/28/10","05:22 PM","0.3007"
"06/28/10","03:22 PM","0.2089"
"06/28/10","01:22 PM","3.0136"
"06/28/10","12:28 PM","0.2568"
"06/28/10","10:30 AM","2.2656"
"06/28/10","08:30 AM","0.1923"
"06/28/10","07:44 AM","0.1142"
"06/28/10","05:44 AM","0.2597"
"06/28/10","03:44 AM","1.8789"
"06/28/10","03:30 AM","1.4199"
"06/28/10","01:30 AM","0.2705"
"06/27/10","11:30 PM","0.4472"
"06/27/10","11:03 PM","0.0976"
"06/27/10","10:29 PM","0.3173"
"06/27/10","09:53 PM","0.1621"
"06/27/10","09:06 PM","0.1113"
"06/27/10","07:06 PM","0.2197"
"06/27/10","06:42 PM","0.4843"
"06/27/10","05:53 PM","0.541"
"06/27/10","05:16 PM","0.0478"
"06/27/10","04:16 PM","0.1406"
"06/27/10","03:32 PM","0.0527"
"06/27/10","02:43 PM","0.0566"
"06/27/10","02:23 PM","0.0292"
"06/27/10","01:54 PM","0.0927"
"06/27/10","12:03 PM","1.4248"
"06/27/10","11:53 AM","0.0117"
"06/27/10","11:23 AM","0.0488"
"06/27/10","11:05 AM","0.0537"
"06/27/10","10:53 AM","0.0126"
"06/27/10","10:15 AM","0.9951"
"06/27/10","09:47 AM","0.0361"
"06/27/10","08:22 AM","0.7363"
"06/27/10","06:22 AM","0.2119"
"06/27/10","04:22 AM","0.1816"
"06/27/10","02:22 AM","0.1806"
"06/27/10","12:22 AM","3.0107"
"06/26/10","10:22 PM","2.2177"
"06/26/10","10:05 PM","0.0371"
"06/26/10","09:48 PM","0.0195"
"06/26/10","09:28 PM","3.1123"
"06/26/10","07:35 PM","0.288"
"06/26/10","05:35 PM","3.125"
"06/26/10","03:35 PM","0.2724"
"06/26/10","02:42 PM","0.3583"
"06/26/10","01:40 PM","0.206"
"06/26/10","12:49 PM","0.0703"
"06/26/10","11:25 AM","0.1425"
"06/26/10","10:56 AM","0.0644"
"06/26/10","09:18 AM","0.5869"
"06/26/10","07:37 AM","0.5341"
"06/26/10","06:41 AM","0.3906"
"06/26/10","05:59 AM","0.4687"
"06/26/10","03:59 AM","1.624"
"06/26/10","01:59 AM","1.5341"
"06/26/10","01:30 AM","0.1484"
"06/26/10","01:21 AM","0.0439"
"06/26/10","01:11 AM","0.0957"
"06/26/10","12:51 AM","0.4824"
"06/26/10","12:02 AM","0.121"
"06/25/10","10:14 PM","12.6748"
"06/25/10","08:33 PM","29.2558"
"06/25/10","08:14 PM","2.6455"
"06/25/10","07:40 PM","0.0117"
"06/25/10","07:15 PM","0.0546"
"06/25/10","06:23 PM","0.2119"
"06/25/10","05:48 PM","0.1542"
"06/25/10","05:17 PM","0.1757"
"06/25/10","04:53 PM","0.1455"
"06/25/10","03:31 PM","0.3095"
"06/25/10","02:22 PM","0.1796"
"06/25/10","01:51 PM","0.3339"
"06/25/10","11:58 AM","1.1035"
"06/25/10","11:36 AM","0.289"
"06/25/10","10:26 AM","0.1728"
"06/25/10","09:45 AM","0.1113"
"06/25/10","09:18 AM","0.0322"
"06/25/10","08:52 AM","0.0654"
"06/25/10","08:12 AM","0.0839"
"06/25/10","06:23 AM","0.2001"
"06/25/10","04:32 AM","0.2548"
"06/25/10","04:05 AM","1.1162"
"06/25/10","02:50 AM","2.373"
"06/25/10","02:17 AM","2.9628"
"06/25/10","01:56 AM","0.2109"
"TOTAL MEGABYTES",,"109.9723"
"The date and time for all data corresponds to Pacific Time (PST/PDT)."

iPhone's detailed usage:

http://img6.imageshack.us/img6/6962/datab.jpg

Ooh and i just woke up from sleeping from ~10:30pm-3:45am and it's showing data at 1am for 9mb? i know i was not online then to be doing anything.

Message was edited by: brad162

I get that the 2AM time is an auditing check-in of sorts -- but she was suddenly doing ~20MB/day in mid-June after being a ~70MB/mo user on average for as far as the AT&T website could go back.

After iOS4, it went back to ~2MB daily. It's unfortunate that it doesn't sound like this wasn't a fix for everyone with this problem.

brad162 wrote:
ok so with does My T-Mobile and the iPhone say different data usage is my question?

This makes absolutely no sense at all. I know T-Mobile's billing is just fine, so what's up with the random data sessions even now that i have auto-fetch/push notifications off?

There is another little trick carriers pull, which is that they charge a minimum amount of data per session, even if you've actually transferred less. Another option is they charge in increments of X kilobytes. So let's say again you have your phone disconnected, you it wants to fetch mail so it connects, asks for new mail, finds out there isn't any, and disconnects. This exchange takes a few hundred bytes to maybe a kilobyte or two, depending on circumstances. But the carrier will happily bill this at some much higher (carrier-specific, I can't say how much it would be) amount. Keeping push enabled actually helps with this: it keeps one long session open, so the 'overhead' is suddenly none (if there is a minimum) or minimal (if they charge in increments of X kilobytes).

This happens to me too. I used to turn my phone off at night and then I was seeing data usage every morning around 7am; which is when I would turn the phone on. ATT initially blamed this on the fact that when I first turned the phone on, anything that was waiting to download or push to me from overnight was coming to me when the phone powered up and BEFORE it had a chance to establish my wifi connection. So, they told me to just leave the phone on overnight to avoid this. I did this and then I started seeing the 2am usage that everyone is talking about on this post (and still seeing even after upgrading to OS4). I informed ATT of this and here was their second response to me:

+*Thank you for taking the time to e-mail AT&T regarding data still counting against your data plan when you are connected to your home hot spot. I apologize for any confusion that this issue may have caused. My name is Jenny Hardridge, and I am happy to help you with your inquiry.*+

+*After receiving your email and contacting you by phone today at 2:00 p.m. CST, we discussed why the data transfer is counting against your data plan when you at home and connected to your hot spot. As we discussed, if you chose Apple alerts during your initial iTunes activation, these alerts will periodically transfer data to your IPHONE 3GS. When this occurs, the IPHONE 3GS automatically defaults to 3G and your data transfer begins. The 3G connection will continue until the data transfer is complete and then the phone will find your Wi-Fi connection. We ask that you always check and make sure the Wi-Fi icon is on as confirmation that you are connected through Wi-Fi.*+

+*Data reverting back to 3G usually occurs when an alert is sent to a phone that is turned off. You can avoid this by leaving your phone on and just putting it on silent, this way the phone is already connected to Wi-Fi and the data would not go against your data plan. If kept on silent, please remember to power cycle your phone a couple of times a week for AT&T billing summary maintenance.*+

CyBeRino, I understand and agree with you about the timing of the usage being billed for whole sessions, and can understand that there is a minimum package charge with some carriers. But our phone usage does not under any circumstances add up to 150MB in a session. The other phone, with another carrier, used identically has used 7MB in 10 days. Most of what we do is on wifi.

But interestingly since I moved the rogue sim card from a 3GS to a 3G phone the 'alleged' usage has stopped. Unfortunately the 3G was also upgraded to OS4 so at this stage there are two variables and I'm not sure it's the OS or the phone that stopped the problem.

When we have a bit more leeway on our plan I'll move the sim card bag to the 3GS with OS4 and see if the problem returns.

Cirrus330 wrote:
CyBeRino, I understand and agree with you about the timing of the usage being billed for whole sessions, and can understand that there is a minimum package charge with some carriers. But our phone usage does not under any circumstances add up to 150MB in a session. The other phone, with another carrier, used identically has used 7MB in 10 days. Most of what we do is on wifi.

Obviously I have absolutely no way of telling you with certainty what the reason for your data transfer was. But I can tell you with certainty it was not an iOS update. As I said, those are well over 200MB.

I am also not disputing that there may be data usage you can't explain-- these phones run a multi-tasking, fully capable OS (though this is not exposed to the user as such) and it is unfortunately not easy to tell what is happening over the cellular data connection with things running in the background. The phone may be fetching e-mail, waiting for pushed data from the Push Notification Service or some other service, etc., without it being immediately apparent.

What I am disputing, is that there is some large amount of data being transferred nightly. This simply does not happen and in fact most of the amounts I've seen here are impossible to even transfer in such a short time span.