Combining Layer Coding and Bandwidth Allocation for Video Distribution on Content Delivery Networks

摘要

In current heterogeneous networks, video can be transmitted using different bit rates and delivered to various end devices with different resolutions and computing power. Single-layer coded video does not meet all of the bandwidth and device requirements. Scalable video coding (SVC) facilitates the transmission of once-encoded video at a target bit rate and the rendering of the video with specified quality. This study investigated methods for distributing and transmitting H.264 SVC-coded videos through content delivery networks (CDNs). The bit-rate allocation of the SVC quality layers with three different ratios (constant, Fibonacci, and exponential) was examined. Three bandwidth allocation strategies for CDN surrogate servers managing the outgoing traffic (stop and wait, stationary quality, and quasi-equal quality) were also evaluated. The use of layer coding in CDNs improves the video service quality in heterogeneous networks. Furthermore, simulation results show that the quasi-equal-quality bandwidth allocation strategy with the SVC layer sizes forming a Fibonacci sequence generally achieves the highest peak-signal-to-noise ratio and shortest waiting time of end users.