On flow aggregation for multicast video transport

Proposes flow aggregation algorithms for multicast video transport. Because of the heterogeneities of network/client environments and users' preferences on the perceived video quality, various QoS (quality of service) requirements must be simultaneously guaranteed, even for a single video source in a multicast connection. It is easy (but ineffective) to provide many video streams according to each user's request. Our flow aggregation algorithm arranges similar QoS requirements of clients into a single QoS requirement, by which the required number of video streams that the video server needs to prepare can be decreased. Then, the total amount of the required bandwidth is reduced by sharing the same video stream among a number of clients. Our algorithm has two variants: one is suitable for sender-initiated multicast connections; the other is suitable for receiver-initiated multicast connections. The proposed algorithms are evaluated and compared through simulation. Then we show that the server-initiated flow aggregation (an ideal case in our approach) is more effective, but the receiver-initiated flow aggregation can also offer a reasonably effective mechanism. Simplified versions of the above two algorithms are also considered in order to save computational cost. These are also evaluated in order to investigate their effectiveness.