AbstractsComputer Science

In this thesis we have investigated a selection of promising scheduling techniques for periodic broadcasting. As ISPs are upgrading their networks to support multicast, they see the opportunity to use less resources to offer their customers quality VoD by making use of efficient scheduling techniques. Of the techniques studied, we found the Cautious Harmonic Broadcasting (CHB) algorithm to be most promising. CHB is designed to schedule video streams over a multicast network. Reduced transmission bandwidth is one of the benefits of using this algorithm. Our most important contribution was designing a CHB streaming server and client, and implementing a prototype of each. Our server prototype has successfully put the CHB algorithm into practice. In our implementation we used the live555 framework, enabling future integration with open source media players like VLC and MPlayer. In our assessment of the prototypes we have performed a series of tests to evaluate the performance. We suggest that conflicting use of variable and constant bit rates can be one factor that can interfere with the CHB scheduling. We also observed that the temporally aligned scheduling scheme in CHB can result in duplicate or lost video frames. From our work we can conclude that it is feasible with today's technology to put a CHB streaming server into operation for a number of subscribers. In this thesis we have investigated a selection of promising scheduling techniques for periodic broadcasting. As ISPs are upgrading their networks to support multicast, they see the opportunity to use less resources to offer their customers quality VoD by making use of efficient scheduling techniques. Of the techniques studied, we found the Cautious Harmonic Broadcasting (CHB) algorithm to be most promising. CHB is designed to schedule video streams over a multicast network. Reduced transmission bandwidth is one of the benefits of using this algorithm. Our most important contribution was designing a CHB streaming server and client, and implementing a prototype of each. Our server prototype has successfully put the CHB algorithm into practice. In our implementation we used the live555 framework, enabling future integration with open source media players like VLC and MPlayer. In our assessment of the prototypes we have performed a series of tests to evaluate the performance. We suggest that conflicting use of variable and constant bit rates can be one factor that can interfere with the CHB scheduling. We also observed that the temporally aligned scheduling scheme in CHB can result in duplicate or lost video frames. From our work we can conclude that it is feasible with today's technology to put a CHB streaming server into operation for a number of subscribers.