TDM

TDM stands for time division multiplexing.  It is a means for multiple sources for sharing a single cable line or wireless frequency connection.

An example of it might simply be four people that shared a common connection.  During each minute each would have 15 seconds of that minute and of every other minute in order to report status at their location.  At the end of their 15 seconds though, whether they are done or not, the control would switch to one of the other three.  A TDM system will do that switching automatically via electronics, but it likewise would allow each source the same amount of time interval.

TDM is used for TDMA cellular systems among other usages.