Cumulative inter-ADU jitter concept and its applications

This paper proposes the concept of cumulative inter-ADU (application data unit) jitter for use in studying the performance of a multimedia system. The concept models the ADU arrivals from a network by keeping the running total of the differences between inter-ADU spacings at the arrival instants and the generation instants. For a given playback delay, the concept can be used to estimate the number of late ADUs. This estimation is done at the entry to the playback buffer rather than at the exit as with existing media synchronization. Extensive simulation results have shown that the ADUs indicated as late by the cumulative inter-ADU jitter are indeed discarded by the playback algorithm. We illustrate its applications by examples. In particular, we highlight the significance of the concept in improving media synchronization algorithms and network-level controls from an application-level perspective