Time-Division Duplexing (TDD) is a transmission method that uses one channel for transmitting and receiving, separating them by different time slots. No guard band is used. Since the transmitter and the receiver do not operate at the same time, there is no possibility of interference between the two.
TDD is like a narrow bridge in a two-way road. Vehicles moving in one lane must wait the vehicles coming from the opposite direction to cross the bridge.
Time-Division Duplexing (TDD) is also known as Half Duplex. In half duplex transmission data can travel in either direction but not simultaneously.
Example of a Half Duplex system is the walkie-talkie.
LTE supports both FDD and TDD, .
LTE stands for Long Term Evolution.
 Erik Dahlman, Stefan Parkvall, Johan Skold, 4G: LTE/LTE-Advanced for Mobile Broadband, Academic Press