Frequency bands are the allocation (available use) of radio spectrum that assigned by a regulatory agency for use for specific types of radio services. There are 2 frequency bands designated for IS-95 CDMA system, band 0 and band 1. Band 0 defines the CDMA channels for use in the 800 MHz frequency band and Band 1 defines the CDMA channels for use in the 1900 MHz PCS band.

It is not possible to use all of the frequencies within the assigned frequency bands due to the need for frequency guard bands. Guard bands are a portion frequency that is unused between two channels or bands of frequencies to provide a margin of protection against signal interference between energy that is transmitted outside the assigned frequency bands of channels operating nears the guard frequency.

Frequency bands are paired to allow for full duplex operation. Full Duplex communication is the process of transferring of voice or data signals in both directions at the same time. Full duplex operation normally assigns the transmitter and receiver to different communication channels. When the communications system uses two different frequencies for simultaneous communication, it is called frequency division duplex (FDD). One frequency is used to communicate in one direction and the other frequency is required to communicate in the opposite direction. The IS-95 CDMA and CDMA system uses FDD.

The amount of frequency separation between the transmitter and receiver frequency bands varies based on the range of frequencies. Generally, the higher the frequency used,...