CDMAOne is a US digital cellular system which promises an increase in capacity. It is standardized as Interim standard 95 (IS-95) by the US Telecommunication industry association (TIA). IS 95 as designed to be compatible with the AMPS frequency band. In 1994, CDMA/AMPS dual mode phones were available by QUALCOMM company. Hence it is said that Qualcomm was the key player in CDMAOne mobile service.

IS 95 uses the principle of Direct Sequence Spread spectrum (DSSS). Hence it allows each user within a cell to share the same channel, and users in adjacent cells also use the same radio channel. As explained in module 4, there is no interference between signals of two different users traversing at the same time. Since the channels can be reused anywhere, CDMAOne completely eliminates the need for frequency planning. The same set of frequencies can be reused in adjacent cells. Hence, frequency Reuse factor=1,cluster size = 1 and system capacity is increased in CDMAOne.