FRames-Ensured-Delivery algorithm for smoothing and multiplexing prerecorded videos

Video-on-demand (VoD) servers normally store MPEG compressed versions of prerecorded videos in order to reduce their network bandwidth demands. Compressed videos have variable-bit-rate (VBR) for a specific compression quality. Transmission of videos on the network at a peak rate results in poor bandwidth utilization, while transmission at a lower rate results in quality-of-service (QoS) degradation. Implementation of a traffic smoothing on the VBR stream, using a buffer at the client receiver, is a widely known approach to overcome the rate variability problem. This paper presents a novel smoothing and multiplexing protocol for prerecorded videos that constructs a FRames-Ensured-Delivery (FRED) and constant-bit-rate (CBR) transmission plan. The protocol achieves perfect QoS, and also provides ideal bandwidth utilization without any frame loss. According to the proposed protocol, the server rate can be changed to explore its affect on the startup latency and the client´s buffer size requirements. Simulation results are provided. We compare FRED protocol to a published work called Join-the-Shortest-Queue (JSQ). FRED protocol overcomes JSQ protocol in places where there is a lack of bandwidth or where the statistical multiplexing gain is not big enough.