# Multiplexing **A method of combining multiple signals into a single signal to be transferred through a shared medium.** ![[Multiplexing.svg|400]] *A representation of multiplexing; a set of signals are multiplexed then transmitted over a single transmission medium; the signals are then retrieved by demultiplexing the combined signal* **Multiplexing** is a method of transmitting multiple signals through a shared communication medium by combining them into a *single signal*. Multiplexing divides the communication medium into several identifiable *channels*. Multiplexing also dictates how the reverse process, known as *demultiplexing*, is done such that the original separate signals can be extracted from the single multiplexed signal. A circuit that performs multiplexing is known as a *[[multiplexer]]* whereas a circuit that performs the reverse is known as a *demultiplexer*. Multiplexing can be largely divided into three types: - **[[analogue modulation]]** - the varying of the *properties* of an analogue signal such that they can be multiplexed onto a carrier signal - **[[circuit switching]]** - the division of a shared medium into dedicated channels of *constant bandwidth* - [[frequency-division multiplexing]] - transmission of several signals over distinct frequency ranges - [[time-division multiplexing]] - transmission of several signals over temporarily assigned time slots - **statistical multiplexing** - the shared medium is divided into *variable bandwidth* channels as required - [[packet switching]] - transmission of several signals by dividing their data into short sections, known as *packets*, and transmitting them as they are ready