An improved error control paradigm for multimedia transmission over wireless networks

Providing quality-of-service (QoS) guarantees over wireless packet networks requires thorough understanding and quantification of the interactions among the traffic source, the wireless channel characteristics, the underlying link-layer error control mechanisms, and the various packet dropping policies adopted by the upper network layers. In this work, we explore the idea of incorporating between some of these different aspects to assist the packet level error recovery. First, we revise the UDP protocol to tolerate certain amount of channel errors and to allow the delivery of partially corrupted packets. Secondly, we propose a novel technique to resolve the problem of missed bits without the need to identify their exact locations. It is based on modifying the stack algorithm for convolutional decoding. The simulation results establish the effectiveness of the proposed approach for detecting and correcting missed bits, which have direct impact on the packet loss and on the overall system performance.