What type of multiplexing assigns specific times for each channel to transmit?

Time Division Multiplexing (TDM) is the technique that specifically assigns certain time slots for each channel to transmit data. In TDM, multiple signals share the same communication medium but transmit in rapid succession, with each signal being allocated a unique time slot. This ensures that each channel gets a dedicated period to send its data without interference from other channels.

This method is particularly efficient in scenarios where the data being transmitted is bursty, meaning that not all channels are active at the same time. By using time slots, TDM allows for a more organized and systematic approach to data transmission, enabling better management of bandwidth resources.

In contrast, the other multiplexing techniques listed function differently. Frequency Division Multiplexing (FDM) divides the communication medium into different frequency bands for simultaneous transmission, while Wave Division Multiplexing (WDM) is used primarily in fiber optics to channel different light wavelengths simultaneously. Code Division Multiplexing (CDM) utilizes unique codes for channel separation. TDM's unique approach to time allocation directly addresses the transmission needs of specific channels, which makes it the correct choice for this question.