Centralized and distributed architectures of scalable video conferencing services

The Multipoint Control Unit-based centralized architecture and Application Layer Multicast-based distributed architecture are mainly used for data distribution in video conferencing services. With the contribution of Scalable Video Coding, the latest extension of Advanced Video Coding, video conferencing services are being further researched to support terminals´ scalability. The main contribution of this research is to answer a fundamental question before a video conferencing service can actually been designed: which service architecture is more suitable for a SVC-based video conferencing service and in which condition? In order to do that, a framework for evaluating SVC-based video conferencing service has been built; intensive simulation results have been also obtained from simulation scenarios which have been designed from the analysis models of the two scalable video conferencing service architectures. The obtained results show that, with a much higher capacity of the MCU, the MCU-based architecture can only guarantee an almost similar video quality with the ALM-based architecture at a trade-off of at least three times higher end-to-end delay.