Issue No.05 - May (2010 vol.59)
Kyungtae Kang , University of Illinois at Urbana-Champaign, Urbana
Lui Sha , University of Illinois at Urbana-Champaign, Urbana
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TC.2009.151
Providing high-quality broadcast services for soft real-time applications over wireless networks such as CDMA2000, which have high bit error rates, requires the control of errors that occur during data transmission. Reed-Solomon (RS) forward error correction (FEC) in the medium access control (MAC) layer performs this role in 3G broadcast services. We propose new analytic models for predicting the performance of RS coding and its execution time, which take into account the memory property of a fading channel, different channel conditions, and a variable level of block interleaving. We identify RS decoding as a significant cause of variability in execution time, taking the form of jitter, which depends on the channel conditions. We analyze the size of buffer required to absorb the jitter under different channel conditions. We then formulate a trade-off between the performance of RS coding and the delay that it causes in transmitting a fixed amount of data with different levels of block interleaving. Finally, we show how to balance the quality with which content is presented against an acceptable buffering delay, which is very important to soft real-time applications, by using an adequate level of block interleaving. This study offers a guide for the provision of efficient broadcast services in real time with stochastically guaranteed quality.
Block interleaving, buffering delay, jitter analysis, real-time broadcasting, worst-case execution time.
Kyungtae Kang, Lui Sha, "An Interleaving Structure for Guaranteed QoS in Real-Time Broadcasting Systems", IEEE Transactions on Computers, vol.59, no. 5, pp. 666-678, May 2010, doi:10.1109/TC.2009.151