time division multiplexing

communications (TDM) A type of multiplexing where two or

more channels of information are transmitted over the same

link by allocating a different time interval ("slot" or

"slice") for the transmission of each channel. I.e. the

channels take turns to use the link. Some kind of periodic

synchronising signal or distinguishing identifier is usually

required so that the receiver can tell which channel is which.

TDM becomes inefficient when traffic is intermittent because

the time slot is still allocated even when the channel has no

data to transmit. Statistical time division multiplexing

was developed to overcome this problem.

Compare wavelength division multiplexing, frequency divisionmultiplexing, code division multiplexing.

(2001-06-27)