An adaptive QoS guarantee framework for SMIL multimedia presentations with ATM ABR service

An adaptive framework to guarantee the application quality of service (APQoS) of a World Wide Web Consortium (W3C) Synchronized Multimedia Integration Language (SMIL) presentation is proposed. This framework cooperates with underlying network protocol stacks and SMIL client/server applications to guarantee continuous playback without interruption for streaming video and audio objects in the SMIL presentation. The framework at the SMIL client periodically monitors the underlying network bandwidth to calculate if synchronization requirements of the SMIL presentation can be satisfied. If not, the framework first tries dynamically to adjust bandwidth allocations among concurrent SMIL objects, according to their media importance (MI) values, at the SMIL media servers. If this scheme fails, other strategies, such as discarding less important objects or sending lower bit-rate objects instead, are provided. We use the ATM available bit rate (ABR) service to provide adaptive QoS support of network transmission because of its inexpensive cost. In simulations, this framework guarantees that all media data in the SMIL presentation can be shown synchronously.