Time-division multiplexing

Time-Division Multiplexing (TDM) is a type of digital or (rarely) analog multiplexing in which two or more signals or bit streams are transferred apparently simultaneously as sub-channels in one communication channel, but physically are taking turns on the channel. The time domain is divided into several recurrent timeslots of fixed length, one for each sub-channel. A sample, byte or data block of sub-channel 1 is transmitted during timeslot 1, sub-channel 2 during timeslot 2, etc. One TDM frame consists of one timeslot per sub-channel. After the last sub-channel the cycle starts all over again with a new frame, starting with the second sample, byte or data block from sub-channel 1, etc.
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Digital multiplexing in which two or more apparently simultaneous channels are derived from a given frequency spectrum, i.e. , bit stream, by interleaving pulses representing bits from different channels. (188 ) Note: Successive pulses represent bits from successive channels, e.g., voice channels in a T1 system .