CDMA is an advanced digital wireless technology invented by Qualcomm, an American wireless communication research and development organization . In this technology every call or data is sent using unique coding method. The way CDMA transmits data through second generation wireless technology is called Spade Spectrum. In this method the user is given a code which can be retrieved at the receiver end. This allows multiple users to share bands of the same frequency, known as multiple access. In Bangladesh, mobile operator Citycell uses CDMA technology. Transmission power on CDMA is very low. So the radiation is less when talking. That is why it is also called Green Phone . Since the CDMA system requires less power, the battery life is increased. CDMA 's call quality is relatively good. The CDMA system is 4 to 5 times more storage capacity than the GSM system at the same bandwidth . Network cell site 110 key. Mr. Covers up. Data transfer rate 154-614 kbps . International ramming facilities are scarce at CDMA. This type of mobile set can not be used in this technology. Its popularity and use is relatively low. The quality of transmission decreases with the increase of users in this technology.