difference between Normal GSM netork & 3G network

GSM: Global System for Mobiles. This technology currently uses frequencies of 800MHz, 900MHz, 1800MHz, 1900MHz. USA & Canada use 800MHz and 1900MHz. Almost everywhere else where this is deployed use 900MHz and 1800MHz frequencies. GSM is also called TDMA (Time Division Multiple Access) because of the way it divides a single frequency into time slots over a single period of time. It does this rapidly enough that the effect is not noticeable. It is also often referred to as a 2G network. Most GSM towers have a maximum range of 30KM line-of-sight. GSM towers also have the ability to transmit a “cell broadcast” message that, in many cases, contains the tower’s location.

3G: W-CDMA (Wideband Code Division Multiple Access) is a type of 3G cellular network. W-CDMA is the higher speed transmission protocol used in the Japanese FOMA (Freedom of Multimedia Access, the brand name for 3G services offered by Japanese Telco NTT) the first 3G system. Also used in the UMTS (Universal Mobile Telecommunications System), the most common form of a 3G network, designed as a replacement for the ageing 2G GSM networks deployed worldwide. Often referred to as 3GSM to differentiate it from other 3G networks, UMTS allows max theoretical download speeds of up to 384KB/s, with uploads at 64KB/s.