Bandwidth efficient video streaming based upon multipath SVC multicasting

The Scalable Video Coding (SVC) Extension of H.264/AVC was designed to support bandwidth efficient and loss resilient video streaming. Its multilayer predictive encoding enables user devices to adapt their video reception by extracting and decoding selected code layers according to device display capability and network throughput. However, this desirable feature is much harder to realize in practice as the reduction of coding efficiency causes inflation of SVC bitstreams. Consequently, an SVC multicast session among clusters of heterogeneous devices may consume more bandwidth than an AVC simulcasting session. In this paper, we propose a bandwidth efficient scheme for conducting heterogeneous SVC multicasting. The proposed scheme employs a combination of three transport techniques: (1) broadcasting of SVC layers in local service subnets, (2) multipath transport of SVC layers over longhaul networks and (3) aggregation of data flows along transport paths. This scheme is particularly suited for delivering SVC bitstreams to different user devices scattered over geographically dispersed local subnets. Preliminary simulation experiments performed over lossless networks showed that the scheme can introduce from 2:1 to 6:1 reduction of up-stream bandwidth for SVC layer transport. It can also maintain 85% transport efficiency while minimizes PSNR loss of most user devices even under heavy traffic. We expect the proposed scheme will achieve better rate-distortion performance than AVC simulcasting over lossy networks if unequal erasure protection (UEP) will be applied to the lower SVC layers. Further investigation of its potential is currently underway.