One of the most interesting wrinkles in the iPhone 4S — whichI review at duration elsewhere — is its status as a “ world phone . ” Unlike previous generations , it supports both CDMA ( Verizon , Sprint ) and GSM ( AT&T , the rest of the earth ) wireless technology decently out of the box . But there are some interesting quirks to this product that may please savvy international travelers .
When Apple released the Verizon iPhone 4 in February , the iPhone 4 ’s product line pay off a little more complicated . Because Verizon ’s internet in the U.S. uses a unlike wireless standard ( CDMA ) than AT&T does ( GSM ) , Apple had to build unlike chipsets for each internet , and thus , different earpiece . But the iPhone 4S change all that : It can get at either the CDMA or GSM web , depending on which carrier you signalise up for .
For consumer on CDMA networks , this new telephone set design is a large plenty when it comes to outside change of location . user of iPhones lock to AT&T have always been capable to go internationally , as GSM is a cellular monetary standard supported all over the human race . It use SIM card ( or , in the iPhone ’s grammatical case , micro - SIM cards ) to utter to networks . When it came to the Verizon iPhone 4 , however , exploiter could n’t travel internationally very reliably with their gadget , since it required a ramp up - in gadget designation number on the CDMA connection , which is n’t that widely used outside of North America and parts of Asia .
But the iPhone 4S plunk for both GSM and CDMA networks , and has a micro - SIM card slot no matter which attack aircraft carrier you pledge to . So if you buy a telephone from a CDMA carrier that does n’t use SIM board , what ’s in that slot ? The answer is something that ’s called a “ tramp SIM . ” If you ’re take to a CDMA aircraft carrier in the states , when you travel internationally , your machine can now flip to an international GSM web using a micro - SIM card . In other Word , when outside the U.S. , you’re able to still get phone calls to your regular number and connect to the Internet , thanks to a micro - SIM that touch base to Sprint and Verizon ’s partner wireless networks in those nation — all at much higher rates than in the U.S. , of course .
That ’s basically the experience AT&T iPhone customer have screw all along . And because AT&T iPhones are lock to the micro - SIM wit in the slot , when you travel overseas , you ’re forced to yield AT&T ’s roaming bang .
But there ’s a raw crinkle that potentially makes the external - range experience well on Sprint and Verizon iPhones than it is on AT&T. dash be after to deal the iPhone 4S with its micro - SIM slot unlock ; Verizon ’s will be initially locked , but if you ’ve been a customer in good standing for 60 Day , you’re able to call Verizon and demand for an “ external unlock . ” ( A Verizon interpreter order me that this is Verizon ’s received insurance policy for all world phones — it ’s just the first time it ’s manifest itself on an iPhone . )
So if you ’re a Sprint or Verizon iPhone 4S client traveling internationally , you may buy a pre - pay micro - SIM notice with dramatically cheaper rates for data and voice calling , rather than pay for international roaming offered by U.S. carrier to their existing customers . ( The only downside is that when you ’re using some other mailman ’s micro - SIM notice , you ’ll be using a local speech sound number rather than your earphone ’s U.S. phone number – so you wo n’t be able to receive song unless you tell masses to call the international telephone set number associated with your card , or apply some third - political party calling service like Google Voice . )
vantage : Sprint and Verizon .
