| GSM (Global System for Mobile Communication) is | | | | used with the GSM SIM cards from different |
| the most widely used wireless mobile | | | | service providers. Thus, if you are planning to shift |
| communication technology in the world. GSM cell | | | | to a new mobile service provider (such as AT&T, |
| phones are highly popular in Asia, Europe and | | | | T-Mobile and Cellular One), you are not required to |
| Australia due to its excellent coverage and | | | | dump your phone. Every time a new SIM card is |
| flexibility, as against to CDMA (Code Division | | | | inserted into the GSM phone device, it starts |
| Multiple Access). | | | | receiving network connection from the new |
| What is a GSM Cell Phone SIM Card? | | | | carrier. |
| Unlike CDMA technology, the GSM phones utilize | | | | When visiting a foreign nation with GSM network |
| SIM (Subscriber Information Module) cards. Simply | | | | available, it is possible to buy a local SIM and save |
| put, a SIM card is a just like any other smart | | | | on the international roaming charges. However, |
| card, such as a credit card. It contains information | | | | you have to provide some documentation to |
| about user's service subscription and account | | | | procure a new SIM in a foreign nation. Also, you |
| settings. It allows the cell phone to access the | | | | will be able to buy only prepaid GSM SIMs which |
| service network through wireless technology. A | | | | require you to pay in advance for services. |
| SIM card also stores essential data such as user's | | | | It is essential to know that GSM phone devices |
| subscription numbers, phone number, security | | | | work on a specific frequency bands for wireless |
| codes and personal contacts. The most important | | | | communication. Dual band works in the frequency |
| benefit of using a SIM card-based cell phone | | | | 900mhz (megahertz) to 1800mhz. Most of the |
| service provider is that the card can be used in | | | | countries follow dual band for GSM services. |
| different phone devices. Thus, you can retain the | | | | However, North America is an exception as the |
| same number while sporting new cell phone | | | | region operates on 1900mhz. To ensure that your |
| devices. | | | | phone continues to operate across the world, buy |
| What are Unlocked GSM Cell Phones? | | | | a Quand band GSM device. It supports |
| Unlocked GSM phones are devices that can be | | | | frequencies from 850mhz to 1900mhz. |