Accuracy of iPhone data counter

gebbel

I zeroed the counter at the airport before a recent trip to the states. To make the long story short, the data I'm being charged for back home exceeds what the data counter says by 30mb. Not a lot of data you may say, however when it's charged at €10 per mb then you end up with a bill of €300 which has me driven demented. Eir have rubbished the iPhone counter saying it's all about their own records.

I'm probably going to have to swallow it, but am putting up a defense based on, among other things, the counter and its accuracy. Thanks.

Peregrinus

You don't say what the variance is. Is your iPhone saying that you used 20 mb while Eir says 50mb? Or does your iPhone say 1 Gb and Eir says, no, it was 1.03Gb?

In general the opinion seems to be that the iPhone data counter is not 100% accurate and that your carrier's figure is definitive. (And the same goes for all smartphones). But the iPhone counter should be not too far off. So if there's only 5% or 10% difference between them, that's an expected discrepancy and the Eir figure is probably corrrect - at any rate, the discrepancy wouldn't suggest that it isn't. But if the Eir figure is 50%, or 100%, or 150% larger than the iPhone figure, that looks odd, and it might be worth digging into things a bit more.

gebbel

OK so the background, I purchased a €20 USA roaming add-on that gave me 200MB of roaming data while over there. A few days into the trip I purchased a second add-on for the same as I reached the 200MB and was informed by SMS (the data counter said something like 180MB).

I connected to WiFi everywhere and only used the mobile data for quick google maps searches while out and about, together with quick browsing of apps like the independent and the journal, no downloading or reckless usage etc. A day after buying the second add-on I received messages saying I was incurring charges but an agent back home told me to ignore them. On the last day of the trip my account was suspended and remains so.
I have told them that essentially I could only have racked up charges if I exceeded 2 x 200MB of data, my phone says I used 250MB on the whole trip according to the data counter on the iPhone.
They won’t reconnect my mobile unless I pay €200 of the €300 charge they say I owe. They also say the true facts of my usage won’t be known until my next billing date which is next Monday.

vinnycoyne

I had the exact same experience with Eir. There’s something really wrong with their USA data roaming add-ons.

Keep hounding their customer care until you get onto a manager and have them wipe out the charges. I managed to get that done twice while I was still in the US. Was a pain but I sure as hell wasn’t paying 200 quid for data I didn’t use.

TheChizler

There's always going to be a difference between what your phone receives and what the network attempts to send to you. In areas with poor reception there could be lots of data that the phone doesn't receive and has to be resent; the network will count all of these data packets while the phone will only count successful ones. Now I have no idea of the proportions involved or how much of an effect this will have.

vinnycoyne

Right, but loading up a single web page while connected to WiFi shouldn’t really use up 200MB... 🀷*♂️

ED E

The process of byte rounding can have an impact, but it shouldn't make 250 into 400, more like 250 into 300 at the most.

Technology Review reports that computer scientists at University of California, Los Angeles, have been probing the systems used by "two large U.S. cell-phone networks"—no names are named—to assess how accurately they calculate data usage. Using data-logging software, the team kept tabs on how the carrier's calculations squared up with their own.

They found that, while carriers often get the calculations right, they often over count. In particular the team found that over counting seemed to happen most when using applications that stream video or audio, or when coverage was weak or unreliable.

The problem boils down to the fact that carriers count data that leaves their network, and not what's received by your phone. Obviously, the two don't always match.

While the effect isn't huge, with typical discrepancies being somewhere between 5 and 7 percent, that's definitely enough to accidentally nudge you over your monthly data allowance. With AT&T and Verizon both charging $15 for straying into each new gigabyte of data over and above your cap, it could even be costing you real money.

The solution, of course, would be to tweak the measurement systems so that they count how much data actually makes it to your phone. Whether that's ever going to happen, though, is a completely different story.

Chizler is correct, and the US telcos are pretty scummy. Eir just use the figures provided by them. It will be almost impossible to prove that Eir were overbilled by Verizon/ATT etc and thus that you were.