Parallel Bindings in Distributed Multimedia Systems

Today's multimedia environments are characterized by different stationary and a growing number of mobile devices, like PDAs or even mobile phones. To meet their requirements regarding configuration and adaptation, multimedia middleware systems often use a flexible flow graph based approach in which multimedia data is processed while flowing from sources to sinks. Here the application has full control about all components and can reconfigure the entire flow graph if needed, which requires sending arbitrary reliable control information in addition to the multimedia data.

This results in a single multimedia data stream consisting of ordered messages with different Quality of Service (QoS) requirements in terms of reliability and deadline. To meet all these requirements, different types of messages must be transmitted using different transport protocols, while the ordering constraints between messages must still be preserved. For this purpose we propose the concept of a parallel binding which allows for the usage of multiple transport protocols to send messages of a single stream with mixed QoS requirements. We also present synchronization algorithms for multiplexing messages after transmission and reconstruction of the original message order of the stream.