=== Frequency Division Multiple Access ===
In this system, each user is allotted a different set of frequencies to operate upon. The uplink(mobile to base station) frequency is different from downlink frequency(base station to mobile).
[[Image:cdma6.jpg|thumb|600px|center|[http://www.ai.u-hyogo.ac.jp/~thai-proj/presen/20051222-Ishikawa.ppt CDMA]]]
'''Time Division Multiple Access:'''In this system each user is allocated a different time slot.Forward link frequency and reverse link frequency is the same. A synchronous switch is responsible to do the time switching.
[[Image:cdma10.jpg]]