Time-division Multiplexed (TDM) - (Time Division Multiplexing) - A technology used by traditional telephone carriers. Cable telephony competes with this.  http://en.wikipedia.org/wiki/Time_division_multiplexing

Time Division Multiple Access (TDMA) - A type of TDM where instead of one transmitter being connected to only one receiver, there are multiple transmitters.    http://en.wikipedia.org/wiki/Time_division_multiple_access