Each source gets a fixed time slot regardless of data availability.
Link Utilization:
Synchronous TDM (Time Division Multiplexing): Each input source is allocated a fixed time slot in a cyclic manner, regardless of whether they have data to transmit. This ensures predictable transmission timing but can waste bandwidth when sources have no data.
Statistical TDM (STDM): Time slots are dynamically allocated only to sources that have data to transmit. Each packet includes an identifier to indicate its source. This improves bandwidth utilization but requires more complex implementation.