A Rate Adaptation Scheme to Support QoS for H.264/SVC Encoded Video Streams over MANETs

Abstract

In recent years, the developments in wireless handheld devices and networking offers the technical platform for multimedia streaming over mobile ad-hoc networks (MANETs). However, providing QoS for multimedia streaming is quite difficult in MANETs due to its physical and organizational characteristics. Due to the high data rate and frame size of multimedia traffic there are times when offered load exceeds the available network capacity. This causes packet drops due to congestion and router input queue overflow. In this paper, we propose a cross layer rate adaptation scheme that provides required rate adaptation between applications transmission rate and network bandwidth. The proposed scheme uses the classical dual leaky bucket (DLB) algorithm to regulate the traffic flow with guaranteed QoS in terms of end-to-end delay. Furthermore, our scheme avoid the congestion in network by controlling the traffic flow of video sequences, this increases the overall network throughput. Our scheme uses the encoding information with QoS requirements of data session (i.e. video stream) provided by application layer to regulate the flow according to the available network resources. We validate our scheme in scenarios where different network size and node mobility degrees are tested in order to show the benefits offered by our scheme. We have used the latest coding standard H.264/SVC video traces to simulate video sources. The quality of received video is measured in terms of network metrics such as end-to-end delay, jitter and packet loss ratio.