Why do I have mysterious cellular data usage (Verizon) every 6 hours on all 3 of my iphone 5's?

mtamaki wrote:

Other questions from a while back in the disucssion -

1. Which way is the data going, push or pull?
2. Why does it use cellular data only and not wifi when it is within a strong wifi network? The 6 hour increment of data use does stop when you turn off cellular data.
3. What on the iPhone, even it were service oriented, requires that much data? Ideas may include documents, email, pictures, video, application data, facetime video and sound ... etc

1. No way to know which way it is going, unless you have an app such as Onavo. However, Settings/Cellular shows cumulatively how much data was sent and how much was received.

2. Being within a WiFi field is not sufficient. WiFi goes off 30 seconds after the screen goes off to save battery, so any data transfer when the screen is off will go over cellular. WiFi, unlike cellular, uses power continuously, whether transferring data or not. This is not an iPhone characteristic; it is the nature of the WiFi standard. But it means that if WiFi stayed on all the time the battery would run down very fast. The exception is when the phone is connected to power. Then WiFi stays on.

3. Settings/Cellular will show you how much data each app uses, but not what the app is using it for. You can turn off individual apps to prevent them from using cellular data. If you take frequent screen shots of that page you can sort of graph your data usage for each app over time.

Regarding the 6 hours, it's more complicated than I implied. (I've worked on telecom billing systems). Whenever you leave one area covered by a Mobile Telephone Switching Office (MTSO) that switch sends a single record to the billing system showing all of the data you used while connected to the switch. These occur at random times. (An MTSO can support many towers, so it is a larger scale than simply a tower). The systems I worked on also had a "close" function at the end of the day that sent a single billing record from the MTSO you are connected to at the close time, which is roughly midnight PST for AT&T. This is so if you stay home for several days you get a summary record each day rather that one after multiple days. Many other carriers around the world use the same billing system.

Verizon uses a different billing system. I'm guessing here, because I never worked on Verizon's system, but since the 6 hour interval is so consistent I suspect that Verizon's MTSOs send the summary record from the MTSO you have been connected to every 6 hours rather than every 24 hours. The reason you see other usage in between is due to the fact that as you travel when you leave the coverage area of an MTSO a summary is generated also. And sometimes you can even switch MTSOs without moving; for example, if your local switch is overloaded you might be transferred to another nearby switch. This is especially common in large cities, where a switch may cover only a few blocks, as opposed to a rural network when the switches can be 15 miles apart.

On a historical note, when AT&T and Apple released the first iPhone a billing record was generated for every data transfer. This resulted in users getting bills of 300 or more pages, listing every transfer. Also, since the record only reported in kilobyte chunks, a 100 byte transfer would be reported as 1 KB. As data was unlimited for the first iPhone this usage inflation on the bill was not a problem for the customer, but it did make people wonder where all that information was going.

I have the same issue. I see mysterious data logs every 6 hours on my phone, even though I was at home all day using my wifi. Its the same times everyday - 2:48am, 8:48am, 2:48pm, 8:48pm, 2:48am. Very strange. I'll talk to the genius bar too and let you know what I find out.

It's happening on my iPhone 6, a 6S and a 7 in my family. I'm concerned thats it's verizon "polling" the phones and increasing data usage. Every time I talk to them they suggest the unlimited plan- - which leads me to believe it's a marketing ploy.

The last technical support person I talked to seemed to think it's something on their end and has promised to get back to me about the issue, although my past experience with Verizon is that it isn't going to help....

there are these charges every 6 hours for DAYS when there's no other data usage on the phone -- that doesn't make sense. And I agree with you -- if it's the carrier pulling the information for their billing purposes, we shouldn't be billed for it.

BUT, I don't believe it's really them pulling it for billing purposes -- that information should be available from those expensive cell towers they built -- there's some "polling" issue going on here.

Nope, that's not it -- there are numerous incidents of data usage between these 6 hour time periods on several of the phones. It's only the phones with low data usage that it's so easy to see between the six hour intervals. But on the line with a lot of data usage, those every six hour postings are still there, you just have to look for them.

Actually, that IS it. When you travel from tower to tower each time you change the tower that you have just used sends data to billing. That's the data you see between the 6 hour intervals. The 6 hour report is for the site you are connected to currently. I've designed phone billing systems, and they are all similar. AT&T users a once-a-day update at 12 AM PST for the current switch reporting, Verizon uses 6 hour intervals for the current switch reporting.

beancter wrote:

then why did verizon tell me that's not what it is? they said its malware -- which I don't believe. and why doesn't it occur on every line in our plan?

Probably because you spoke to level 1 customer support, or, possibly even an outsourced, contract employee.

beancter wrote:

then why did verizon tell me that's not what it is? they said its malware -- which I don't believe. and why doesn't it occur on every line in our plan?

Verizon didn't tell you anything. A Verizon tier 1 CSR, probably in India, and paid $1 an hour, told you that. The don't know much other than what is in their script. And they are rated on how many calls they can complete in an hour, so they will say anything that will get you to hang up. The average tier 1 CSR is in the job for 3 to 6 months before they move on. There is no malware on an unjailbroken iPhone, so you are right not to believe it.

You said it DID occur on every line in your plan:

Nope, that's not it -- there are numerous incidents of data usage between these 6 hour time periods on several of the phones. It's only the phones with low data usage that it's so easy to see between the six hour intervals. But on the line with a lot of data usage, those every six hour postings are still there, you just have to look for them.

It won't appear on any phone that has had no data usage.

With iOS 7, apps can continue processing in the background, so it's important to close them when not using them. All it takes is one app to perfrom background communications with some server at fixed intervals.

Try shutting down one device, then start it again but do not invoke any apps. Is there still communications going on? (There will be some, since iOS would be doing it.)

My family is experiencing the exact same issue. Three phones, two 5cs and one 5s, all with this weird cellular data usage at 6 hour intervals that seem to reset periodically (eg when the phone is turned off then back on). We are also Verizon customers, and of course they claim they have never heard of it. The usage was so high because of this on one of our phones it actually exceeded our data plan. And in each case, this behavior began when we upgraded our phones to the new 5 versions. We had all been using iOS7 on our old 4 and 4s. What makes this even more intriguing is that two of us migrated our settings from our backed up iPhone 4 phones. No new apps and no setting changes.

It would be really nice to know if any users from other cellular carriers are experiencing this as well. We will be turning app cellular access off on one of the phones to see if it changes...

Sounds like the polling interval for VZ's billing servers. (Sprint pulls the usage data every 15 minutes)

Use an app that can track your data usage (OpenSignal, Dataman, etc.) they should show the same usage as what's on your VZ account.

I'll be turning off cellular tomorrow as well and see what happens. But I hope that isn't the only solution!

So if the usage isn't the same on the app and on my VZ account, then does that mean it isn't VZ's billing servers?

Technically, the app should reflect the same as what Verizon shows... just that the usage updates may be delayed by VZ.

If there is a stark difference in usage, call verizon and ask about the usage stats.

Use the power of iOS 7 and see what apps are using the most data. (Settings > Cellular > *scroll down*)