Technology: CDMA use the spread spectrum so they can maximize the available bandwidth. Allow user transmit entirely spectrum frequency all the time. GSM use Wedge spectrum call carrier frequency. This frequency divide number of time slot. Each user assigned the different time slope until ongoing call finished. GSM use TDMA and FDMA. TDMA provide multi user by chopping the channel into different time slice. FDMA provide multi user by separating different frequency. Data transfer CDMA use EVDO Technology which maximized the download 2mbps GSM use Edge technology which maximize download 384 Kbps slower CDMA Security CDMA provide unique code to every user while GSM concentrate to narrow band so CDMA more secure than GSM. Spectrum Frequency Both CDMA and GSM use 850 Mhz and 1900Mhz