QoS-based dynamic layered multicast routing for video transmission

Multicast services have been increasingly used in large scale continuous media applications. Unfortunately it is not scalable due to the number of forwarding states and control messages required to maintain trees. At the same time the receivers´ heterogeneity requirements of these continuous media applications prompt the necessity for QoS-driven. A lot of research had been done to solve such problems. Our protocol, which is one of the important solutions based on Diff-Serv architecture, reduces the number of forwarding states and the tree maintenance overhead by allowing several multicast groups to share the same delivery tree. The first objective of this paper is to introduce a protocol which reduces the number of forwarding states by allowing several groups to share the same tree and accepts groups only if there is enough available bandwidth, at the same time the proposed algorithm consider the delay requirements which is required for real time applications. Second, continuous video transmission for heterogeneous receivers using layered multicast video approach. Validation of the proposed protocol is done via simulation. Experimental results show that the proposed protocol aggregate trees if the candidate tree has the QoS requirements (bandwidth and delay), while keeping the same performance of aggregation ratio.