An agent-based approach to intrastream synchronization for multimedia applications

摘要

Multimedia synchronization control is essential to overcome the network delay variance problem in order to provide continuous and smooth playout of a multimedia stream. This paper proposes an agent-based intrastream synchronization scheme, which adapts to network delay fluctuations for continuous and smooth playout of a multimedia stream. The scheme employs three types of agents: application manager agent (AMA), user agent (UA) and negotiation/renegotiation mobile agents (NMAs/RMAs). AMA creates UA, NMAs and RMAs. UA monitors the synchronization parameters (delays, rate of change of delays, losses, etc.) as well as studies the user expectations. The NMAs/RMAs are used to negotiate/renegotiate synchronization parameters. The scheme operates in two phases: start-up synchronization and re synchronization. In start-up synchronization phase, a NMA is created by AMA to negotiate the delays and rate of change of delays with the intermediate nodes in the network on the basis of application requirements. In resynchronization phase, a RMA is created by AMA to renegotiate the delay parameters and resynchronize the presentation units of a stream, whenever UA reports violation of application requirements. Also, resynchronization phase takes care of link failures. The scheme is simulated in several network scenarios for verifying its operation effectiveness. It maintained the synchronization parameters well within the sustainable values. The benefits of the scheme are: asynchronous delay negotiation and adaptation, flexibility, adaptability and supports component based software development.