Explain about TDM.
Time Division Multiplexing processes information of different transmitters successively in defined time segments for transmission over one channel. Time Division Multiplexing is differentiated in synchronous and asynchronous multiplexing.
Asynchronous Time Division Multiplexing
Single data streams are classified in variable time segments and subsequently transmitted using the asynchronous time division multiplexing procedure. Thereby transmission occurs in no definite order. Each time segment receives a channel information number to separate them again in the demultiplexer procedure.
Synchronous Time Division Multiplexing
Using the synchronous method, single data streams are classified in defined time segments for subsequent transmission in predetermined order.
Using this TDM procedure for example 8 x Gigabit Ethernet applications can be multiplexed to one 10 Gigabit signal. In the following this independent 10 Gigabit signal can easily be connected to a DWDMCDWM multiplexer. Consequently more signals per wavelength can be transmitted and the entire xWDM system is utilized more efficiently. Theoretically up to 240 Gigabit Ethernet signals can be transmitted using one pair of fibers by adding TDM multiplexer to a xWDM system.