FDM (Frequency Division Multiplexing), TDM (Time Division Multiplexing), and WDM (Wavelength Division Multiplexing) are all multiplexing techniques used in telecommunications to transmit multiple signals simultaneously over a single communication channel. This process allows for efficient use of resources and can significantly increase the amount of data that can be sent over a network. Multiplexing is also sometimes referred to as muxing. It is applied in copper, fiber and wireless systems. The most common five techniques are FDM, TDM, WDM, CDM and SDM. FDM divides the available frequency.