TABLE OF CONTENTS There are two types of radio channels used in the EVDO system; one for high-speed data only and another for voice and medium-speed data services. The characteristics of EVDO radio channels include frequency bands, frequency reuse, channel multiplexing techniques, RF Power levels, RF power control, and channel structure.
The two key RF channel types used in the EVDO system are IS-95 CDMA for voice and low speed data and EVDO data for high-speed packet data. EVDO data only radio channels use the same radio channel bandwidth as the IS-95 CDMA RF channel and they can use the same radio transmission plan in the cells of the cellular system.
The EVDO physical RF channel is divided into 64 coded channels. Of these 64 channels, 60 used for traffic (user data) and 4 are used for control purposes.
Frequency allocation is the amount of radio spectrum (frequency bands) thats assigned (allocated) by a regulatory agency for use for specific types of radio services. There are 10 frequency bands designated for 1x EVDO, bands 0 through 9.
It is not possible to use all of the frequency bands assigned to a service provider 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. The signal interference may come from a channel that is outside the assigned frequency bands of channels operating near the guard frequency.
