Apple labels the iPhone 4S as a “world phone” and for good reason. According to a report by Macworld, Sprint will sell the iPhone 4S with an unlocked SIM card slot from day one, enabling international travellers to use it outside the USA at much cheaper rates.
The iPhone 4S ships with support for both CDMA (Sprint, Verizon) and GSM (AT&T) protocols. But while the latter is prominently used across the world, the CDMA technology is only in use in the United States and some parts of Asia. This means that phones that only run on the CDMA network, like the iPhone 4, are rendered unusable if you cross the borders of the USA.
With the iPhone 4S, however, Sprint customers will be able to insert any standard micro SIM card from a local carrier in whichever country they happen to be in and steer clear of the hefty international roaming charges levied by the US-based carrier. Verizon customers will also be able to get their iPhone 4S units unlocked for international use if they have been a customer in good standing for 60 days and ask nicely.
None of this means that iPhone 4S users will somehow be able to use carrier-locked iPhones with other carriers within the United States, however, and AT&T customers are still going to find themselves strapped to the company outside the borders of the USA. It’s somewhat ironic that the CDMA carriers, which have historically been restrictive and less convenient for international travellers, are suddenly the ones truly capable of offering a “world phone”.