Over the past couple days, many iPhone users have noticed an unusual update dialog when connecting their phone to sync with iTunes. Rather than the familiar "an update is available" message, this dialog notes an update to the phone's carrier settings:
What's it mean? According to Apple's support article about iPhone carrier settings:
iTunes 7.7 and later has the ability to update the carrier specific settings on iPhone with iPhone 2.0 software or later. Carrier settings updates are small files (about 10k) that are downloaded from iTunes to be installed on your iPhone. The carrier settings can include updates to the default APN (how iPhone accesses the carrier's cellular data network), special dialing codes at Settings > Phone > [Carrier] Services, default settings for Stocks, Maps, Weather, and other items.
OK, so what's it really mean? MobileCrunch claims the update contains only icons--specifically, two AT&T M-Cell icons for your iPhone's menu bar, to be displayed when you're connected to one of AT&T's upcoming 3G MicroCells.
Commenters at TUAW, however, say the update also adds settings for Saudi Arabia's Mobily network and United Arab Emirates' Etisalat network. The iPhone will be available in these countries in the next few weeks.
If you're wondering what the 3G MicroCell is, it's sort of mini cell tower for your home or office--it connects to the AT&T mobile network and then provides a stronger local signal (covering approximately 5000 square feet) for up to four simultaneous users. Subscribers to the service apparently also get unlimited calling minutes while connected to the MicroCell, essentially making it a replacement for traditional home phone/data service. (AT&T's own page for the 3G MicroCell is currently down for "maintenance.")
This story, "Behind the IPhone's Carrrier-settings Update Message" was originally published by Macworld.