QoS-aware scalable video streaming using data distribution service

Abstract

Enabling Real-Time video streaming over wireless networks is a challenging task due to the time-varying channel conditions and the limited network resources. The instability of wireless networks leads to problems such as limited and time-varying bandwidth, and unexpected traffic congestion when transmitting a burst of video streams. In Real-Time video streaming, each frame must be delivered and decoded by its playback time. Recently, layer coding (LC) has enabled Real-Time and scalable video streaming to clients of heterogeneous capabilities by dropping upper enhancement layers without the need of re-encoding and with much less bit rate. However, layer coding still facing unfair layer protection problem in which packets from the base or lower layers might be dropped while there is a chance to drop packets from the upper enhancement layers. Losing packets from the base layer can significantly affect the delivered video quality and sometimes lead to an interruption especially in error-prone networks as wireless networks. Architectural solutions at the middleware level introduce higher flexibility, more efficiency in development time and more QoS control. This work investigates the behavior of video streaming over Real-Time publish-subscribe based middleware. We propose and develop an unequal layer protection mechanism for Real-Time video streaming based on the Data Distribution Service (DDS) middleware. A combination of video quality of service (QoS) is proposed to adapt the video transmission to the time-varying network changes. The performance of Real-Time video streaming is measured over IEEE 802.11 g WLAN network. The results show a graceful degradation of video quality while maintaining a robust video streaming free of visible error or interruptions. This is due to the intentionally dropping of some enhancement video stream layers in order to protect lower layers, and therefore maintain a continuous video flow of acceptable quality. Numerical results indicate that the proposed scheme is able to achieve higher throughput and improve the average received video quality especially in a large number of video subscribers.