1. Statistical Time Division Multiplexing
Presenter:
Arlien McDougal
PHS 221
Prof. Jiang

2. Objectives Explain what is Statistical Time Division Multiplexing
Describe how STDM work
Compare Asynchronous Multiplexing to Synchronous Multiplexing

3. What is Statistical Time Division Multiplexing

4. Statistical Time Division Multiplexing is a process of time multiplexing where the time slots on the time division multiplexing (TDM) medium between Statistical time division multiplexing (STDM) multiplexers are dynamically allocated.
STDM multiplexers are known as asynchronous multiplexers to differentiate them from the synchronous time division multiplexers used in PSTN.

5. In this allocation any input to the STDM multiplexer can be assigned to any time slot on the Time Division Multiplexing medium.
Time slots on the TDM medium are assigned to input channels that have data ready to send over the TDM medium to a distant STDM multiplexer.

6. HOW DOES IT WORK?

7. To accomplish dynamic allocation of any input to any time slots, the TDM multiplexer places a header on the data that each input channel has ready to transmit.
The header informs that receiving STDM multiplexer which output channel is to receive the data.

8. ILLUSTRATION

9. ASYNCHRONOUS vs. SYNCHRONOUS

10. ASYNCHRONOUS vs. SYNCHRONOUS
Dynamically assign slots in the TDM path.
Better use of capacity.
Greater number of channels.
Better utilization of composite TDM circuit.
Synchronized time slot in the TDM path
Wastes of capacity.
Limited number of channels.
Utilization can be improved by using a STDM and increasing the number of input channels.

11. QUESTIONS