Frame-based periodic broadcast and fundamental resource tradeoffs

Multimedia streaming applications consume significant amounts of server and network resources due to the high bandwidth requirements and long durations of audio and video clips. For popular videos, periodic broadcast techniques exploit the client's buffer space and network reception bandwidth capabilities to reduce server and network transmission bandwidth requirements. We study the fundamental tradeoffs among the server/network bandwidths, client buffer, client reception bandwidth, and the playback startup delay for periodic broadcast. We adopt a fine-grained fluid transmission model and consider a class of frame-based periodic transmission schemes which assign a fixed transmission bandwidth to each frame in the video, and continuously transmit each frame according to this rate. We develop and explore broadcast schemes that minimize the transmission overhead while guaranteeing a particular playback delay to clients, when clients are resource (buffer or bandwidth) constrained. We also consider the problem of using a single transmission scheme to satisfy clients with heterogeneous rate constraints, and develop an appropriate reception scheme to jointly minimize the client playback startup delay and client buffer requirements. Extensive evaluations of these different scenarios suggest that an operating region defined by a playback startup delay of a few tens of seconds, client reception bandwidth equal to 2-4 times the mean video bandwidth, client buffer space sufficient to accommodate 15-40% of the video, and server and network transmission bandwidths of 3-5 times the mean video bandwidth, is very attractive from the viewpoint of the server, network, and client.