TDMA (time division multiple access)
Digital modulation technique that allocates a discrete amount of frequency bandwidth to each user to permit many simultaneous conversations. Each caller is assigned a specific time slot for transmission. TDMA provides improved spectral efficiencies over analog systems. A derivative of this standard used in North America is called NA-TDMA. Other TDMA-based cellular systems include GSM, D-AMPS, PDC, DECT and enhanced TDMA.