My experience with Sprint, International Roaming, and iPhone 4s (pre trip)
I'm going to China soon.
It's been a long and winding road with the iphone 4s and sprint, but I thought I'd share what I've learned:
1. iphone bought late in November was immediately "enabled" by Sprint for global roaming. I've had sprint for 5 years, so that's why.
2. here's the interesting part: I'll be in China which has GSM and CDMA. These will switch based on "the strongest signal", there is no way for user to switch. So even if my Passport SIM card works there, I'll have to find a place where signal is greatest according to the following information bar readings:
China Telecom: CDMA
China Unicom or China Mobile: GSM
3. I still get different answers from Sprint regarding my own GSM SIM. One rep said: "Just connect to iTunes and it will "unlock" automatically." Another said "it should work, but I can't say for sure."
4. When I go to China, I was told to "turn cellular data off" to avoid exorbitant data charges, but turn voice roaming on to get voice and text.
5. Finally, for dialing from China to US, another glitch is that I first need to know which network I'm on (see carriers above) then dial either the CDMA access code first "00 1 xyz xxx xxxx" or the
GSM Access Code first: "+ 1 xyz xxx xxxx"
The bottom line seems to be that the whole setup (phone, radio, sprint, etc.) is not designed from a user perspective. I just want to go to China and use a local SIM to avoid the $2.50 / minute voice calling (though text at $.50 is < text charge on the Global SIM card I bought).
Maybe someone else can weigh in on actual experience in China? And whether I'm right about the above? Thanks. This whole thing gives me a headache