2G & 3G — CDMACode Division Multiple Access

Spread spectrum modulation

Originally developed for the military

Resists jamming and many kinds of interference

Coded modulation hidden from those w/o the code

All users share same (large) block of spectrum

One for one frequency reuse

Soft handoffs possible

Almost all accepted 3G radio standards are based on CDMA

CDMA2000, W-CDMA and TD-SCDMA