For the past two months, on multiple online forums, Windows Phone 7 (WP7) users have been reporting that their devices seem to be transmitting data via 3G even when the device is ostensibly logged onto a Wi-Fi network, and should be transmitting data without incurring network charges. Furthermore, the patterns of high data usage don't seem to correlate with how the devices are being used.
One WP7 user, posting to Howard Forums, reported seeing 2MB to 5MB of data consumed per hour, despite only having Gmail, Yahoo, and a Weather Channel app active on the phone. "This even happens at night when I'm not getting any emails at all." At that rate of consumption, a monthly 2GB plan with a network carrier would be exhausted in just 16 days.
Another WP7 owner, posting to Paul Thurrott's Windows Phone Secrets blog, said that he'd seen his data consumption spike after streaming a radio station all day. "Now I am completely positive I was on Wi-Fi because I am always on it when at home, but it still did not register it through the app apparently," he wrote.
By default, the WP7 operating system prioritizes data transfers via an available Wi-Fi connection, instead of using 3G. But some users suspect that there may be a bug in the Wi-Fi prioritization mechanism, or that feedback sent from the phone to Microsoft via 3G or operating system update checks may be behind the mysterious data consumption.
According to a Microsoft spokesperson, "We are investigating this issue to determine the root cause and will update with information and guidance as it becomes available."
While WP7 launched in October 2010, it's apparently gotten off to a slow start. To date, Microsoft has declined to reveal the number of end users who have purchased WP7 handsets.
In December 2010, however, it did say it had shipped 1.5 million of the devices to mobile operators and retailers, spanning 60 carriers in 30 countries. In addition, the WP7 app store's growth rate has already surpassed the WebOS app catalog.
If Microsoft confirms that there's a data-gobbling bug and traces the cause, industry watchers expect a fix to come packaged as part of the first major WP7 update, which Microsoft has said will get released soon. The update will also add cut and paste functionality to WP7.