Cross-layer QoS control for video communications over wireless ad hoc networks
EURASIP Journal on Wireless Communications and Networking
IEEE/ACM Transactions on Networking (TON)
Efficiency of FEC coding in IP networks
Proceedings of the International Conference and Workshop on Emerging Trends in Technology
Flexible macroblock ordering for context-aware ultrasound video transmission over mobile WiMAX
International Journal of Telemedicine and Applications - Special issue on healthcare applications and services in converged networking environments
A self-extracting accurate modeling for bounded-delay video services
Computer Communications
Interaction relationships of caches in agent-based HD video surveillance: Discovery and utilization
Journal of Network and Computer Applications
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The development of broadband networks has led to the possibility of a wide variety of new and improved service offerings. Packetized video is likely to be one of the most significant high-bandwidth users of such networks. The transmission of variable bit-rate (VBR) video offers the potential promise of constant video quality but is generally accompanied by packet loss which significantly diminishes this potential. We study a class of error recovery schemes employing forward error-control (FEC) coding to recover from such losses. In particular, we show that a hybrid error recovery strategy involving the use of active FEC in tandem with simple passive error concealment schemes offers very robust performance even under high packet losses. We discuss two different methods of applying FEC to alleviate the problem of packet loss. The conventional method of applying FEC generally allocates additional bandwidth for channel coding while maintaining a specified average video coding rate. Such an approach suffers performance degradations at high loads since the bandwidth expansion associated with the use of FEC creates additional congestion that negates the potential benefit in using FEC. In contrast, we study a more efficient FEC application technique in our hybrid approach, which allocates bandwidth for channel coding by throttling the source coder rate (i.e., performing higher compression) while maintaining a fixed overall transmission rate. More specifically, we consider the performance of the hybrid approach where the bandwidth to accommodate the FEC overhead is made available by throttling the source coder rate sufficiently so that the overall rate after application of FEC is identical to that of the original unprotected system. We obtain the operational rate-distortion characteristics of such a scheme employing selected FEC codes. In doing so, we demonstrate the robust performance achieved by appropriate use of FEC under moderate-to-high packet losses in comparison to the unprotected system