How am I using data in my sleep?

July 20, 2010 8:05 AM

All of a sudden, my data usage with AT&T has gone way up. How can I be using data while I'm asleep? And on wifi?

Historically, I have never gone over 164 MB of data usage in a month. Because of this, I recently switched to the 200 MB data plan.

Also, I should note that this is my first full cycle with an iPhone 3gs rather than a 3g.

So I am 5 days into the billing cycle and have already used 20 MB of data.

Here's the kicker: I'm *almost* always on wireless. We have wireless at home and at work. And looking at my data usage in the detailed summary at the AT&T page, I am apparently using data when I am connected to wireless. And at 2am when I am asleep. I don't get it!?

I called AT&T yesterday and the customer service person told me that my wireless is probably being "interrupted" and the phone is getting information from apps during these down times. I don't feel like this is the case.

Any ideas?

posted by morganannie to Technology (29 answers total)

You're not the first person to notice this. I haven't read a convincing explanation of what's going on, but especially with the switch to metered service, it's clearly a problem.

To clarify, when you say "wireless," you mean "wifi." Cellular is wireless too.
posted by adamrice at 8:08 AM on July 20, 2010

Response by poster: Yes, sorry - I meant wifi.
posted by morganannie at 8:09 AM on July 20, 2010

I don't see what the problem is here -- if you are 5 days into a 30 day billing cycle and you have used 20 MB of data, you are on track to use 120 MB of data. That's far below the 164 that is your historical upper limit.
posted by proj at 8:18 AM on July 20, 2010 [3 favorites]

That doesn't answer your question about data being used during times that you're not using the phone, but it answers the total usage question. Make sure your phone is set to join WiFi networks without asking so that apps that update during down time will do so over WiFi and not over 3G perhaps?
posted by proj at 8:19 AM on July 20, 2010

Response by poster: proj - I should have mentioned that 18 MB were used in 2 days of the 5. So 9 MB per day for those days. Basically though, I'm concerned with the usage at times when I am connected to wifi. And yes, I have it set up to auto-connect to wifi networks.

Bwithh - yes, I am connected to wifi at home and at work. How do you know when/if your wifi breaks down? I work at a library and people are always connected to the wifi and if it broke down we would have complaints all day...which doesn't happen.
posted by morganannie at 8:24 AM on July 20, 2010

the phone will check various things depending on how you've got it set up - email is the biggest thing; it'll pull that every so often or get pings from the push servers every once in a while. (whether it should do this over WiFi rather than 3G when it's asleep is another question that I don't know the answer to.)

if you've updated to iOS 4, there's a Cellular Data toggle in General under Settings - turn this to Off and your phone straight-up won't use 3G for data anymore. this may affect how up-to-date things like your calendar and email are, but whether or not that matters to you is up to you. (personally, I have the notifications about that stuff turned off and I just check them manually - even with Push on, my email usually stays out of date enough that I've gotta force it to refresh itself to see what's really going on.)
posted by mrg at 8:25 AM on July 20, 2010 [1 favorite]

Response by poster: mrg - won't it try to use Edge if I turn off 3G?
posted by morganannie at 8:30 AM on July 20, 2010

That switch turns off all cellular data - both 3G and Edge.
posted by Magnakai at 8:41 AM on July 20, 2010

I think mrg was using 3G as a shorthand for cellular. In iOS4, if you disable Cellular Data, it won't use EDGE or 3G.
posted by proj at 8:42 AM on July 20, 2010

Best answer: Here's a discussion over at Apple's support boards. One person (on the last page) said "This is happening on my AT&T blackberry, and my wife's AT&T Palm Pixi, all starting on the day the new tiered plans came out... "

That's just one random person on the Internet, but it's intriguing.

There does seem to be a new pattern of heavy scheduled usage around 1:00-2:00 AM. And apparently, the iPhone turns off wifi when it's asleep, but not cellular. From glancing through that thread, a number of people have spoken to Apple and AT&T support, but nobody has gotten a straight answer.
posted by adamrice at 9:09 AM on July 20, 2010

Just a guess and probably not super-applicable: My Android phone has a setting for the WiFi policy that will by default switch to cellular data after a certain idle period on the WiFi, in order to save power. Might there be something similar on your phone?
posted by themel at 9:22 AM on July 20, 2010

Pogue (I think) covered the 2am data stuff a couple weeks back. It's your phone sending use data to the phone company to ensure their view of your usage matches the networks view of your usage. You're not charged for that time/data.
posted by NotMyselfRightNow at 9:28 AM on July 20, 2010

Response by poster: NotMyselfRightNow - It shows up on my bill. I believe I am being charged for it. For example:

7/19 2:34 am 337 KB sent
7/20 2:52 am 156 KB sent



Also, it may be important to note that in my usage detail ALL of these transactions are "Sent" nothing is being "Received".
posted by morganannie at 9:36 AM on July 20, 2010

Response by poster: And even if it is just data being transferred from phone to phone company, why isn't it happening on wifi?
posted by morganannie at 9:39 AM on July 20, 2010

Strange. I just looked at my bill (in detail) and discovered periodic overnight uploads during times when

a: I'm asleep
b: I was home with wifi

The largest I saw was 34000KB or 34MB!
posted by jz at 10:00 AM on July 20, 2010

Best answer: morganannie: wifi is turned off when your phone is locked, so it'll use 3G/EDGE instead. If you jailbreak, you can get a package from Cydia that will keep wifi enabled when the phone is asleep, but it's hard on the battery.
posted by Emanuel at 10:47 AM on July 20, 2010

Response by poster: Emanuel - thanks. That explains why things are happening when I'm sleeping. I guess I'll have to turn off cellular data while I sleep!
posted by morganannie at 11:16 AM on July 20, 2010

I just looked at my at&t bill data details and I also have an upload nightly around 2:05am, generally in the 1-7 mb range. I have never noticed this before, thanks for pointing it out. I'll poke AT&T to see what that's all about and let you know what they say.
posted by 8dot3 at 11:23 AM on July 20, 2010

Could it be sending location data back to Apple over the cellular network instead of Wi-Fi?
posted by KevCed at 12:18 PM on July 20, 2010

I am Morganannie's husband. It's also worth noting that I have an Iphone 3G (updated to 4.0 OS) and I do not experience the same overnight data uploads as her. It cannot be the wifi going out because I would have the same issue.

If this is ATT gathering data from her phone and being charged, more of us need to be calling and complaining. Please keep us updated if anyone else experiences these charges and ATT's response.
posted by WhiteWhale at 12:38 PM on July 20, 2010

So I've been watching this thread with interest. I have an iPhone 3G running iOS4, and I checked my bill, and I *do* show the same overnight data transfers, usually between 2-2:30am every night, anywhere from 5 or 6MB to 100-200KB. In my current usage, these overnight transfers account for 68% of the total usage. So this does not appear to be specific to the 3GS.

I, too have wifi throughout my house. My googling shows quite a number of forums with people discussing this same issue. Some speculated that it's just a nightly upload of your day's data usage. However there are days when I have usage charges during the day AND at 2am-ish.
posted by DiscourseMarker at 1:00 PM on July 20, 2010

Your iPhones are part of a big botnet. Like werewolves, they are waking up at night for some dark purposes...

Seriously, this looks like remote access by either Apple or AT&T. You should all complain. A lot.
posted by knz at 1:13 PM on July 20, 2010

So, I have an iPhone with iOS4, and I do not see these transfers happening. I am on the unlimited data plan though. Perhaps this is only done on metered plans?
posted by Joh at 2:36 PM on July 20, 2010

I am on the unlimited data plan, and I have these transfers.
posted by DiscourseMarker at 3:25 PM on July 20, 2010

I just checked my usage data and found a puzzling thing. Yes, I see a connection every night around 1:35am, but even more confusing for a moment was the fact that this was the only usage I showed all day long. I definitely use my 3G connection at work every day. Given this, I'm guessing that the middle of the night is when daily usage is reported back to AT&T. They're not actually transmitting the amount of data reported at that time, they're updating their system with the amount of data you used since the last time they checked your usage.

I do see some additional reports of data transfers on my report for yesterday, and one of them was at lunchtime when I recall switching briefly to airplane mode in hopes that my 3G connection would decide to start working again when I switched airplane mode off. Maybe there are certain circumstances that invoke updates throughout the day, but most days I don't ever trigger any extra updates? I can understand why the transactions in the middle of the night would be baffling if you were also seeing other line items each day at other times.

This doesn't explain why you're seeing more data transfer, but I wouldn't be surprised if it was some app running in the background as AT&T suggested. I haven't updated most of my apps to new iOS4 versions yet, so I haven't seen a usage spike yet (I actually used less data than normal last month), but the other day I was noticing slowness while playing a game on my phone and went to check what other apps were running in the background. I counted as I closed 20 apps, some of which I don't think I'd used for days. If I had a few apps transmitting data occasionally all day long, every day, I think that would start to add up pretty quickly.
posted by des at 5:57 PM on July 20, 2010

Try reporting this to The Consumerist and see what happens. Maybe that would help get a response from Apple.
posted by IndigoRain at 7:35 PM on July 20, 2010

I think des has it. I just checked mine and there is a transfer every day for a month at 2:27 am. I moved on 6/26 and used a lot of maps and those were the days the data transfer was the largest.
posted by phox at 12:44 AM on July 21, 2010

Response by poster: des - the late night charge is not the only usage I am showing all day long. I'd say on an average day now, I have about 10-15 of them and they range really widely in size.
posted by morganannie at 4:46 AM on July 21, 2010

I just checked my bill. I've got a 3GS/iOS4/unlimited plan and similarly have wifi at home. I'm not seeing these transfers. It is worth mentioning that I only see "Sent" data, except for text messages which show "Received". I do see large random transfers but those are when I'm awake and are likely maps or videos. They also correlate with when I'm at work and don't have easy WiFi access.

I'm saying my bill looks reasonable.

I hate to say it but what the AT&T rep said might actually be true. I'm not sure how you would verify this except by waking up at 2:30 every morning to check.

Do you keep your phone plugged in at night? If my phone is charging, it won't drop WiFi even when it goes to sleep. Well, it won't drop VPN over WiFi which makes me think it keeps WiFi enabled. I pretty much keep my phone charging all the time, at work and at home.
posted by chairface at 8:10 AM on July 21, 2010