How US Carriers Miscalculate Data Usage

Every month, US telcos calculate how much data customers have crunched through on their phones and charges them accordingly. But a new study suggests that telcos might not be adding things up quite right.

Technology Review reports that computer scientists at University of California, Los Angeles, have been probing the systems used by "two large US 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 problems is 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 per cent, that's definitely enough to accidentally nudge you over your monthly data allowance. With AT&T and Verizon both charging $US15 for straying into each new gigabyte of data over and above your cap, it could even be costing customers real money.

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


    Interesting distinction between data sent and received, but realistically, the cost to the carrier is the data they send - that's what clogs their networks and requires them to upgrade infrastructure. It makes sense for their charges to be proportional to their costs. Some good research anyway!

      $15 a GB! Wow, down in Australia, we get slapped with 25c per MB over and above the cap, ($15 only gets you an extra 60MB, not a GB) and remember that both data sent and received is included in the total. I guess that this is a huge incentive to stay well below your limit so an extra 5% to 7% may not be a problem.

    Australian ISPs do the same thing - as do universities (although counting typically happens as the data enters the ISPs or universities network from upstream, not as it's sent to the customer - I'd guess US telcos are doing the same thing, but don't know). Another point of difference is packet size on the wire - each physical medium has a different encapsulation, so you'll never actually be able to add up the data you receive and make it match the data billed (and because it depends on packet sizes etc, theres no easy way to adjust for it).

    Counting data actually delivered would be near impossible.

    I honestly think this post is useless,
    Based on what you guys have based the story on then technically you Internet connections such as Adsl/dsl fibre etc are miscounting too.

    If you request the data from the carrier or ISP and you drop connection or loose packets that comes down on the customers end. If you download a file twice causes the first one corrupted your downloading the data twice, it's not by what you receive it what leaves the carrier.

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