In legacy GSM network, we usually use GPRS( General Packet Radio System) and then EDGE(Enhanced Data Rates For GSM Evolution). EDGE is the one which provides the highest throughput 384Kb. But with the passage of time more applications are added in the global network like facebook,orkut and media applications like youtube and iptv which demands more bandwidth. But it’s not possible to deliver these type of application in the existing GSM network. Parallel there is one more group which is working on CDMA2000 which is able to deliver the bandwidth more than GSM network. But the main problem with CDMA is that no roaming functionality is available.