Time division multiple access (TDMA) is a channel access method for shared medium (usually radio) networks. It allows several users to share the same frequency channel by dividing the signal into different timeslots. The users transmit in rapid succession, one after the other, each using his own timeslot. This allows multiple stations to share the same transmission medium (e.g. radio frequency channel) while using only the part of its bandwidth they require. TDMA is used in the digital 2G cellular systems such as Global System for Mobile Communications (GSM), IS-136, Personal Digital Cellular (PDC) and iDEN, and in the Digital Enhanced Cordless Telecommunications (DECT) standard for portable phones. It is also used extensively in satellite systems, and combat-net radio systems.
TDMA is a type of Time-division multiplexing, with the special point that instead of having one transmitter connected to one receiver, there are multiple transmitters. In the case of the uplink from a mobile phone to a base station this becomes particularly difficult because the mobile phone can move around and vary the timing advance required to make its transmission match the gap in transmission from its peers.
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
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