Time division multiple access (TDMA) is digital transmission technology that allows a number of users to access a single radio-frequency (RF) channel without interference by allocating unique time slots to each user within each channel. TDMA works by dividing a radio frequency into time slots and then allocating slots to multiple calls. In this way, a single frequency can support multiple, simultaneous data channels. TDMA is used by the GSM digital cellular system.

The TDMA digital transmission scheme multiplexes three signals over a single channel. The current TDMA standard for cellular divides a single channel into six time slots, with each signal using two slots, providing a 3 to 1 gain in capacity over advanced mobile-phone service (AMPS). Each caller is assigned a specific time slot for transmission microwave transmission.

TDMA features--

• Shares single carrier frequency with multiple users



• Non-continuous transmission makes handoff simpler



• Slots can be assigned on demand in dynamic TDMA



• Less stringent power control than CDMA due to reduced intra cell interference



• Higher synchronization overhead than CDMA



• Advanced equalization is necessary for high data rates



• Cell breathing (borrowing resources from adjacent cells) is more complicated than in CDMA



• Frequency/slot allocation complexity



• Pulsating power envelop: Interference with other devices