Time Division Multiplexing (TDM)
- It is digital multiplexing technique.
- Channel is not divided on the basis of frequency but on the basis of time.
- Total time available in channel is divided between several users.
- Each users is allocated to particular time interval called time slot.
Types of TDM
1] Synchronous TDM
2] Asynchronous TDM
1] Synchronous TDM
- Each device is given some time slot to transmit the data over the link whether the device has any data to transmit or not.
- Each device place its data into the link when its time slot arrives.
- Each device is given its data onto the link when its time slot arrive.
- Each device is given the possession of line turn by turn.
- If any device doesn't have to transmit the data then its time slot remains empty.
2] Asynchronous TDM
- Channel is not divided on the basis of frequency but on the basis of time.
- Total time available in channel is divided between several users.
- Each users is allocated to particular time interval called time slot.
Types of TDM
1] Synchronous TDM
2] Asynchronous TDM
1] Synchronous TDM
Number of Input = 5
Number of Slot in frame = 5
|
- Each device is given some time slot to transmit the data over the link whether the device has any data to transmit or not.
- Each device place its data into the link when its time slot arrives.
- Each device is given its data onto the link when its time slot arrive.
- Each device is given the possession of line turn by turn.
- If any device doesn't have to transmit the data then its time slot remains empty.
2] Asynchronous TDM
- It is also known as statistical time division multiplexing.
- In this TDM, the time slot is not fixed i.e. time slots are flexible.
- Total speed of input lines can be greater than the capacity of the parts.
- In asynchronous TDM, we have n input lines and m lots. m
- Slots are not pre-defined rather slots are allocated to any of the device that sends the data.