A) To take, or be capable of taking, several different signals and send them through one source. b) To combine multiple signals, usually in such a way that they can be separated again later. There are three major multiplexing techniques. Frequency division multiple (FDM) assigns each signal a different frequency. This is how radio and television stations in the same metropolitan area can all transmit through the same air space and be individually tuned in. Time division multiple (TDM) assigns different signals different time slots. Different programmes can be broadcast over the same channel using this technique. More technically, the MADs use TDM for luminance and chrominance. Space or path division multiplex allows different television stations in different cities to use the same channel at the same time or different people to talk on different telephones in the same building at the same time. c) A stream of all the digital data carrying one or more services within a single physical channel. d) To transmit two or more signals at the same time or on the same carrier frequency. e) To combine two or more electrical signals into a single, composite signal.