Owners of Apple's new iPhone 4S consume twice as much data as iPhone 4 users, and triple that of iPhone 3GS owners, according to a UK-based network management firm.
After analysing traffic on a unnamed European mobile carrier, Arieso concluded that the iPhone 4S was the biggest contributor to a boost in data consumption in 2011 over the year before.
Arieso, which counts mobile network providers O2, Telefonica and Vodofone among its clients, said that iPhone 4S users download an average of 276% more data than people with an iPhone 3G, Apple's 2008 smartphone.
On the data upload side, iPhone 4S users beat iPhone 3G owners by 320%.
Apple started selling the iPhone 4S in the U.S. and several other countries -- including the U.K., France and Germany -- on Oct. 14. Since then, Apple expanded iPhone 4S availability to dozens of other markets, and plans to roll out the device in China a week from today.
Altogether, iPhone 4S owners consumed three times more data than iPhone 3G users, and double that of people with an iPhone 4, Apple's 2010 model, said Arieso.
While the company could measure data use for individual smartphone models, it wasn't able to pinpoint the exact kind of bits that were being transmitted or received. "The drill-down causes are not directly available to us," admitted Michael Flanagan, Arieso's chief technology officer and the author of his company's report, in an interview today. "So we have to look at the feature capabilities of the phones."
So Flanagan attributed the iPhone 4S' voracious appetite to a pair of causes.
"The most salient difference between the iPhone 4S [and earlier models], and we think the root cause, is its cloud-based capabilities," said Flanagan.
He cited the constant synchronization via iCloud -- Apple's sync and storage service that also is accessible to users of the iPhone 4 and iPhone 3GS -- as one, and Siri, the voice-activated assistant available only on the iPhone 4S, as the other feature most likely to cause increased data consumption.
iCloud's synchronization means more data on the download and upload channels, said Flanagan, especially when that data consists of audio and video files.
"Say I download the latest "Archer" episode from iTunes to my laptop," he said. "The next day it's been automatically downloaded to my iPhone. And if I take videos using the iPhone, it's automatically pushed to another device via iCloud. Together [the downloads and uploads] can account for the increases."
Siri, which some reports identified as the most likely reason why iPhone 4S data consumption was double that of the iPhone 4, is probably also a cause, Flanagan said.
"It's not exclusively Siri, but it is a major component, maybe even the dominant one," said Flanagan.
Although the data sent and received for each Siri event is relatively small, when all the requests for information and the resulting downloads are taken into account, voice has the capability to dramatically boost data consumption, Flanagan argued.
"In the aggregate, the effect could begin to be dramatic," he said. "It's like if you're staring at an avalanche bearing down on you. Any one of those snowflakes doesn't weigh very much -- and doesn't pose any danger -- but in the aggregate they can bury you."
Arieso's study also noted the increased appetite of so-called "extreme users," who, Flanagan said, consume much more than their fair share of data.
"One percent of users consumed upwards of half of all the data," Flanagan said, referring to the unidentified European carrier whose traffic it analyzed. "That's not specific to the market we looked at, but is a worldwide problem. Extreme users are becoming even more extreme."
That may seem like doom and gloom for carriers, but Flanagan argued that it was even more an opportunity for data providers -- provided they reacted intelligently.
"There are ways for network operators to address the consumption increase," Flanagan said, "such as the insertion of small cells to surgically respond to very localized demands, like very small base stations in homes."
Those devices shunt cellular data within a very small area to the Internet, bypassing the usual cellular towers.
"There is going to be consequences of consumption for the carrier, but I look at it as spending money to make money," Flanagan said. "In the end, I think the benefit will outweigh the costs to them."
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer , on Google+ or subscribe to Gregg's RSS feed . His e-mail address is firstname.lastname@example.org .
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