ணோடேஆஓஈளோஊணீணாடீஓண்

Twisting technology
Wireless carriers in the United States operate over two different networks: Code Division Multiple Access and Global System for Mobile Communication . Though each technology transmits voice and data, they do so in different ways, which makes them incompatible. As a result, you can't take a phone and use it on or vice versa.
Of the . carriers, and use while , and smaller carriers such as such as MetroPCS and U.S. Cellular use. Though Nextel is part of Sprint, Nextel-branded phones use a third technology called iDEN, or Integrated Digital Enhanced Network.
coverage is very strong in the United States, particularly in rural areas, but GSM service has a larger global footprint (it's the standard in Europe, for example) and GSM phones use the convenient SIM cards, which you allow you to, among other things, switch phones more easily. Also, when taken on a global scale, users will find a wider selection of handsets.
With that in mind, if you travel overseas frequently or you enjoy switching out your phone often for the newest model available, then GSM is the better choice. Not all GSM phones will work overseas, however, so be sure to read CNET's . But if you'll be making calls mostly in the United States, theis an equally good option. What's more, some phones now also support GSM networks for international use