There's a CDMA model of 4S (not sure if available in India), but it is carrier locked (as far as I know it cannot be unlocked unlike GSM).. So a particular CDMA iPhone will only support SIM of that network operator with which is has been locked to. I don't know if any Indian Network offers CDMA locked iPhone with their SIM..
MEID : A mobile equipment identifier (MEID) is a globally unique number identifying a physical piece of CDMA mobile station equipment. The number format is defined by the 3GPP2 report S.R00 but in practical terms it can be seen as an IMEI but with hexadecimal digits.
ESN : Electronic serial numbers (ESNs) were created by the U.S. Federal Communications Commission (FCC) to uniquely identify mobile devices. ESNs are currently mainly used with CDMA phones compared to International Mobile Equipment Identity (IMEI) numbers used by all GSM phones.
I guess its simple to understand. Now difference between ESN & MEID is :
In handsets having ESN, it can be used by only one operator and these type of handset can't be unlocked to use on another operator.
In handset having MEID, mostly tehre is a SIM Card Slot. So, any CDMA operator Sim card can be used in these kind of handset. Even Handsets not having Sim Card Slots can be used with different operators if necessary firmware is supported by the CDMA Operator.
P.S: MEID Sim Card Slot & GSM Sim Card Slots are different.
okay so here's the deal:
But the iPhone 4S supports both GSM and CDMA networks, and has a micro-SIM card slot no matter which carrier you subscribe to. So if you buy a phone from a CDMA carrier that doesn't use SIM cards, what’s in that slot? The answer is something that’s called a “roaming SIM.” If you're subscribed to a CDMA carrier in the states, when you travel internationally, your device can now switch to an international GSM network using a micro-SIM card. In other words, when outside the U.S., you can still get phone calls to your regular number and connect to the Internet, thanks to a micro-SIM that connects to Sprint and Verizon’s partner wireless networks in those countries—all at much higher rates than in the U.S., of course.
That’s essentially the experience AT&T iPhone customers have known all along. And because AT&T iPhones are locked to the micro-SIM card in the slot, when you travel overseas, you’re forced to pay AT&T’s roaming charges.
But there’s a new wrinkle that potentially makes the international-roaming experience better on Sprint and Verizon iPhones than it is on AT&T. Sprint plans to sell the iPhone 4S with its micro-SIM slot unlocked; Verizon’s will be initially locked, but if you’ve been a customer in good standing for 60 days, you can call Verizon and ask for an “international unlock.” (A Verizon spokesperson told me that this is Verizon’s standard policy for all world phones—it’s just the first time it’s manifested itself on an iPhone.)
From what I understand:The CDMA phones sold by Apple (Sprint/Verizon in US) are world phones and work on both CDMA & GSM/UMTS networks and are termed as world phones. iPhone 4s sold by GSM carriers and the unlocked iPhone 4S are only GSM/UMTS phones.The, so called, world phones are not available unlocked and thus to legally own a iPhone 4S you must have got them unlocked from the service provider you have got the world phone from. Once you get it unlocked I believe it should even work with GSM/UMTS networks in India..
Apple makes a single iPhone 4s model. att locks it on their network. verizon and sprint have somewhat better policies. iphone 4s was aimed to be a world phone to save the hassle of manufacturing two versions (gsm and cdma) for different operators around the globe. from what i know the cdma edition is sold in very few markets. most markets get the gsm edition. all the units come with hardware to support both the networks. of course, carriers are free to apply their own limitations.
Apparently, verizon allows one customer to get only one phone unlocked like this once every ten months. So how are their so many iPhones floating around on ebay.
BAD ESN?? (Unpaid Balance or lost/stolen phone)
Apple makes a single iPhone 4s model. att locks it on their network. verizon and sprint have somewhat better policies.
iphone 4s was aimed to be a world phone to save the hassle of manufacturing two versions (gsm and cdma) for different operators around the globe.
from what i know the cdma edition is sold in very few markets. most markets get the gsm edition. all the units come with hardware to support both the networks. of course, carriers are free to apply their own limitations.
I have an unlocked iPhone 4S and I am very very sure that it does not support CDMA