subject: Understanding Gsm Cell Phones [print this page] There are two main network technologies in use by the big cellular carriers in the United States and worldwide: CDMA and GSM Cell Phones.
These two dominate about 90% of the cellular services market as of today and are being used by about 2 billion people around the globe. In the U.S.: T-Mobile and ATT Cell Phones are GSM Cell Phones while Verizon and Sprint mobile phones use CDMA).
Knowing what CDMA and GSM Cell Phones have to offer will help you decide which one is the ideal network technology for you, and thus, help you choose the right carrier for you. This will undoubtedly help you choose exactly what you need.
GSM VS. CDMA
Although most areas are covered by both carriers, by checking your cellular service provider's coverage maps, you may notice that in some areas cellular service is offered only by Global System for Mobile communications carriers or only CDMA carriers. So the area you'll be using your cellular phone in is an important factor in choosing a network technology. If, for example, ATT Cell Phones have an area that is covered by both CDMA and GSM carriers, there is no difference between the two.
Global System for Mobile communications SIM (Subscriber Identity Module) Cards are preferred by most users due to the ease of swapping a card from one device to another, carrying the contacts and information to a new cellular phone within a minute. On the other hand, most CDMA CSPs have an operator database that backs up your data, and will transfer it to your new phone quite easily. This is not as easy as just swapping a card, but it has the advantage of user's info and phone-book recovery in case the phone is lost or stolen with the SIM card in it.
Today, as cells phones are being used for a lot more than just calls and text messaging, the method and speed in which data is transferred to and from a phone is an important factor for many users.
CDMA - uses 1XRTT, a single carrier Radio Transmission Technology, with a high speed (up to 144Kb per second). GSM - uses GPRS (General Packets Radio Service) for data transfer, with relatively slower data bandwidth, but has an advantage over CDMA's 1XRTT - the ability to make data calls and voice calls simultaneously - without one blocking the other.
Understanding the distinctions between the two network technologies will help you chose a cellular service provider that best fits you.
