Designing the ON-OFF CBR transmission schedule for jitter-free VBR media playback in real-time networks

This paper addresses the problem of designing the CBR transmission schedule (CTS) for jitter-free media playback. Comparing to the VBR transmission schedule (VTS), CTS is known to have advantages in low overhead and complexity for managing real-time communications. However, media data are usually compressed as VBR streams with noticeable bit-rate variabilities. Conventional CTS approaches usually require large buffer size or workahead to resolve this problem. In this paper, a linear-time CTS algorithm with the minimum system resources is proposed to transmit VBR media for jitter-free playback. Different from the conventional approaches, the obtained CTS is with the ON-OFF switch behavior. As the ATM transport mechanism used in current high-speed networks, it transmits fixed size cells in the ON period and zero cells in the OFF period. In 1993, Sohraby has shown that the general ON-OFF resource has a simple multiplexer queue length distribution function. It is very easy to do the call admission control (CAC) for real-time networks. In this paper, empirical studies to different VBR media streams are explored. The obtained results demonstrate that the proposed approach is effective and efficient.