Q: Can I keep my phone when I switch cell phone companies?
A: Generally, you'll have to buy a new phone. But you shouldn't always have to.
The U.S. does not have a single standard wireless phone network technology, and most cell phones are designed to work on only one type of network. That means when you switch from one cell phone company to another one with an incompatible network, you'll have to get a new phone.
However, several cell phone companies operate on compatible networks. There's no technical reason why you shouldn't be able to take a phone from one to another. In fact, most of the small rural cell phone companies say they don't lock the phones they resell.
Yet freedom of movement for most consumers is often denied between compatible networks because most of the largest cell phone companies put software "locks" on phones to prevent consumers from taking their business elsewhere. That's unfair and anti-competitive.
Q: What does it mean when my cell phone company "locks" my phone?
A: Some wireless carriers in the United States install software on the phones they sell to prevent that phone (also called the "handset") from working on another network, even if that network uses a compatible technology. These locks often require consumers to purchase a new phone if they switch services.
Q: How do cell phone companies justify locking my phone?
A: Some companies claim that they have to do this because they subsidize new customer's handsets and will otherwise lose money. However, you are paying for that subsidy through your monthly cell phone bill. If you switch carriers before your one- or two-year contract is up, you will still face the hefty early termination fees that cover the carrier's up-front costs.
When your contract expires, you should be able to take the phone from one cell phone company to another if they use the same technology. When your old company locks your phone, it is making it harder for you to choose a new provider. It's the same power these companies had over you when you lost your phone number if you changed service.
Q: If my phone isn't locked, is it possible to take my phone from one cell phone company to another?
A: Maybe. There are 4 different types of technology that wireless phones carriers use for their networks. (See below for more information about each network.) When your old carrier and your new carrier use the same network technology, then there should not be any reason why you can't take your number-and your phone-with you.
Q: Which network does my cell phone company use?
TDMA has been out dated in the USA
Other cell phone companies: Other small cell phone service providers have networks that operate on one of the technologies listed above.
* iDEN is a technology that only Nextel uses.
Q: What is GSM, and if I have a GSM phone will it work on any GSM service?
A: GSM stands for Global System for Mobile, and is a type of Time Division Multiple Access. The two are different enough not to be compatible, but both rely on the same theory of splitting multiple calls into fractions of time.
GSM phones have a SIM card inside the phone (not much bigger than the tip of your thumb to the first knuckle) that contains subscriber details and security information. SIM stands for Subscriber Identity Module, and it tells your carrier's network which phone is which, and how to bill you for the calls you make. Software locks on these phones prevent you from using a SIM card that belongs to a competitor.
Ask your current cell phone company, or one you are considering, whether it locks the phones it sells and whether the company will remove the lock. A few carriers have indicated they will unlock the phone after you have been their customer for a few months.
Q: What is TDMA, and if I have a TDMA phone will it work on any TDMA service?
A: TDMA stands for Time Division Multiple Access. It's a method of digitizing and compressing wireless phone calls to allow several calls to share the network at the same time.
Now, can you take a TDMA phone with you? Probably not. No technical barriers exist that prevent this from happening, but big cell phone companies typically lock the phone. Whether or not your phone is locked, chances are you'll need the code from your original carrier to move to a new carrier.
Q: What is CDMA, and if I have a CDMA phone will it work on any CDMA service?
A: CDMA stands for Code Division Multiple Access. It's another method of digitizing and compressing wireless phone calls to allow several calls to share the network at the same time.
As for taking your phone to a new carrier, maybe. Some CDMA carriers will let you take a phone from a different CDMA carrier, particularly if they sell a similar phone themselves. These phones are sometimes locked. It always pays to check with the carrier before you sign up.
Q: Can I take my phone around the world?
A: Your current wireless carrier might let you use the same phone for international travel and just bill you for roaming -- but that can be very expensive. If you're a regular international traveler then ask prospective carriers about their policies and rates before you sign up. Get any information about roaming rates and availability in writing.
Just as keeping your phone while switching networks in the United States is complex, using the same phone abroad depends on the network technology that the country's wireless providers use.
International pre-paid cards are available that work with GSM phones in areas with GSM networks. If they work with your phone, they can save you a lot of money and improve your coverage and call quality.