Scheduling and Synchronisation

The major test of the (often real-time) delivery of a multimedia system is in the final delivery of the media. If the media is integrated it is frequently needed to tb synchronised over an exacting time frame ( e.g. Video and audio has to be synchronised for a movie clip to make any sense)

Analysis of the traffic bandwidth and buffering of a given system will yield some appreciation of the problem. In order for a system to be effective some guarantee of the delivery of the media is needed. In most systems two guarantees for delivery are made:

Delay Guarantee

-- worst case delay in delivering the data

Throughput Guarantee

-- the minimum rate of service of a data stream.

Delivery of data involves scheduling the delivery of the data. Two approaches are commonly used:

Generalised Round Robin (GRR)

-- A compromise solution between first come first served and round robin strategies.

Carry-Over Round Robin (CORR)

-- Based on a time-line divide and allocate policy moderated by a queuing schedule.

The reader is referred the Chapter 10 of Networked Multimedia Systems by Raghavan and Tripathi for full details of these type of analyses.