Abstract: Security system is a very essential term in wireless communication like multiple accesses. When we go through multiple access method we will find TDMA (Time Division Multiple Access), FDMA (Frequency Division Multiple Access) are working with time & frequency respectively. For security purpose TDMA and FDMA have to apply additional security features to keep those channels secure. Whereas in CDMA (Code Division Multiple Access) it has its own coding technique and it gives us auto security for data. The security features are coming from PN Sequence (for spreading), Walsh code (for channel coding) and power control. In this sequence CDMA is developed for further wireless communication such as 3G and 4G which overcomes GSM technique.