End-to-End Performance of Robust Multiple Description Scalar Quantizer

Transmissions over hybrid wireline-wireless networks suffer both packet losses and bit errors. To facilitate delay-sensitive audio/video communications over hybrid networks, low-delay error recovery techniques, such as forward error correction (FEC) and multiple description coding (MDC), are utilized to provide protection against bit errors and packet losses, respectively. As a means of joint source-channel coding, the robust multiple description scalar quantizer (RMDSQ) was introduced to combat both packet losses and bit errors. In this paper, a novel RMDSQ system is proposed by utilizing both MDC and FEC-based techniques. In the sense of rate distortion, end-to-end performance of the RMDSQ system against packet losses and bit errors is compared with that of individual FEC and MDC-based techniques. Instead of the traditional two-state Gilbert channel model, a three-state Markov chain is proposed to model hybrid networks and work as the testbed. Experimental results show that the proposed RMDSQ system achieves higher robustness against increasing packet losses and bit errors. In contrast, FEC-based techniques achieve better performance against bit errors; however, their performance deteriorates significantly due to packet losses.