Network-aware error control using smooth and fast rate adaptation mechanism for TCP-friendly Internet video
Interactive error control to mitigate error propagation from packet loss is one of the serious challenges to Internet video applications to date. Error control scheme performance is highly dependent on how to coordinate the source error resilience options based upon the observed network status, especially for real-time interactive (i.e. unicast) Internet video. In this paper, a smooth and fast rate adaptation mechanism (SFRAM) (Kim et al., Proc. Packet Video Workshop 2000, May 2000), which does TCP-friendly rate adaptation based on the TCP throughput equation, is used to coordinate the network-aware error control (NAEC) scheme for the best end-to-end video quality. Since the adopted smoothing and weighting scheme of SFRAM enables the capture of only distinct network variations, the various source-level error resilience tools such as reference picture selection (RPS), video redundancy coding (VRC) and I-MB (intra-macroblock) refresh can be dynamically switched. To figure out the best operating mode of interactive error control upon the network status (e.g., round trip time and packet loss rate), performance of each error resilience option is first investigated with a virtual packet loss and feedback scenario. Then, extensive ns-2 network simulation with integrated ITU-T H.263+ encoder is conducted to confirm the efficiency of the proposed NAEC with realistic TCP background traffic and feedback while it behaves in a TCP-friendly way. From simulation, SFRAM-driven NAEC demonstrates enhanced error control over fixed error schemes.