Enhanced RLME Protocol for Layered Video Multicast in Diffserv Networks

摘要

A layered video multicast scheme in differentiated service (DiffServ or DS) networks is proposed in this research. This scheme provides various QoS level guarantee for heterogeneous users with an improved performance in network congestion adaptation. The proposed system consists of three key components: extended active queue management, hierarchical priority marking, and receiver-driven layered multicast with ECN (RLME). Particularly, we introduce an RLME protocol that effectively utilizes advanced features of active queues such as random early drop (RED) and early congestion notification (ECN) in DS networks. The RLME protocol quantitatively estimates the network congestion level via ECN and packet loss to improve the adaptation capability to network congestion, and utilizes the priority service from DS networks to minimize the packet loss effect on reconstructed video quality. The simulation shows that the proposed system successfully achieves stable and controllable video QoS guarantee for heterogeneous video clients over DS networks.