It refers to the second generation of wireless communication technology and it is mainly based on GSM ( Global System for Mobile communications ) technology. It can give data rates of up to 64 kbps using digital modulation techniques so 2G is digital technology. It can also provide enabled services like SMS ( Short message service ) and MMS (Multimedia message service). Global System for Mobile communication is a global system for voice communications which can provide better quality voice calls and it can use a bandwidth of 200 K hz. For data communications, 2.5G which is GPRS (General Packet Radio Service) which is able to transmit data packets through the cellular network which can give theoretical speed of 115kbps however practically speed of around 35 kbps is achieved with this technology. In order to increase the data rates, further enhancement to this 2.75G is EDGE (Enhanced Data rates for GSM Evolution) which is designed to deliver enhanced data rates of around 384 kbps.