Multiple Access in Satellite Systems

Technique	Principle	Feature
FDMA	Each station uses a separate frequency band	Simple, less flexible
TDMA	Stations transmit in assigned time slots	Efficient for digital traffic
CDMA	Stations use different spreading codes	Interference-resistant, flexible
DAMA	Capacity assigned on demand	Efficient for bursty VSAT/rural traffic

Satellite multiple-access techniques.

DAMA: Demand-Assigned Multiple Access allocates a channel only when a station has traffic and releases it afterwards, so a shared pool of channels serves many intermittent VSAT or rural-telephony users efficiently.