What is an unlocked phone

What is a SIM Card and what is unlocking


A GSM phone is not directly linked to you|GSM phones are not tied to your phone. Instead, it has a removable card, called a SIM (subscriber information module) and this SIM has a unique number on it. This is what identifies you to your carrier


Ordinary cell phone service works so that the unique number in your mobile phone (its ESN) is used by the cell phone carrier to identify you and your information. The wireless carrier 'knows' that a particular phone's serial number is your mobile phone and knows to send telepohne calls to that phone whenever someone dials your phone.

The important deviation about this is that you can put your SIM into any compatible mobile device (and just asbout all gsm phones are compatible) and that phone will now behave as your mobile phone, because your service provider sees your sim nside the phone. They couldlnt care less that you've switched phones, all they care about is if they can delvier service to your SIM card
And now for the really breathtaking part of this. In theory, you can transfer your SIM car dot any phone, the other way is also true. Any phone can communicate with any SIM card. So, if you've already purchased a luxurious mobile phone that you enjoy and have leanred the features, if you switch from one mobile phone carrier to a new one, you don't have to buy a new phone. You can keep the phone you've mastered, and all you need to do is switch the first service provider's SIM with your new service provider's SIM.

But, some providers 'lock' their devices, meaning that their phones have been programmed to only work with their specific SIM cards. Overthrowing that programming - unlocking your cell phone so it can work with any GSM carrier - is what this is all about.
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What is GSM Technology? Is it different than normal cell phone service? How do I know if I am on a GSM network or not?

GSM is a type of mobile phone technology. The more common type of cell phone service in North America is CDMA technlogy, but just about every other country in the world uses primarily or only GSM.

For you as the consumer of your phone, there is no difference at all between using a mobile phone on a CDMA network or a phone on a GSM network. Unfortunately, the two different infrastructures are not compatible with each other so you cant switch between phones if your mvoing form GSM to CDMA or vicea versa

If you have a T-Mobile or AT&T(formally cingular) then you are using a GSM phone.


Can I buy an unlocked phone without signing up for service?

Yes, there are several ways to purchase an unlocked cell phone without needing to sign up for a year or two of service that you mightn't want. You can simply buy a used or new GSM phone on the internet or a friend or somewhere like that.

If you buy a used cell phone from an individual always make sure it unlocked before commiting to purchase.

You can also purchase Unlocked Cell Phones from online stores such as my favorite,J-Cellular or Best Buy