The Free On-line Dictionary of Computing (30 December 2018):

time division multiplexing
TDMA
time division multiple access

    (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 division
   multiplexing, code division multiplexing.

   (2001-06-27)