basics

[pavanred]

* GSM - The "Global System for Mobile Communications" network type is the most widely used network standard in the world. All GSM phones use SIM cards to store personal info, like Contacts, SMS, etc. If you are looking for a phone with a SIM card, "World Phone" or an "unlocked phone," chances you are looking for a GSM phone. GSM carriers include, but are not limited to, T-mobile, Cingular/AT&T, Orange, O2, Vodafone, Mobistar, Digifone, Airtel

* CDMA - The "Code Division-Multiple Access" network type is the second most popular network type. Phones on these types of networks do not support SIM cards, so they cannot be used interchangeably, nor "unlocked" for use on different networks. CDMA Carriers include, but are not limited to, Sprint, Verizon, KDDI, Alltel, Bell, Telus, US Cellular

* iDEN - The "Integrated Digital Enhanced Network" network type is basically on its way out, as a network standard. The iDEN network was pioneered by Motorola has been used in the USA with lackluster success. The iDEN network is rumored to be slated for decommissioning as a commercial network and re-deployment for military use (after the year 2010). Nextel has been the sole iDEN provider in the USA, but alas, an acquisition by Sprint has all but doomed the iDEN network.