Receiver-driven layered multicast

Abstract

State of the art, real-time, rate-adaptive, multimedia applications adjust their transmission rate to match the available network capacity. Unfortunately, this source-based rate-adaptation performs poorly in a heterogeneous multicast environment because there is no single target rate -the conflicting bandwidth requirements of all receivers cannot be simultaneously satisfied with one transmission rate. If the burden of rate-adaption is moved from the source to the receivers, heterogeneity is accommodated. One approach to receiver-driven adaptation is to combine a layered source coding algorithm with a layered transmission system. By selectively forwarding subsets of layers at constrained network links, each user receives the best quality signal that the network can deliver. We and others have proposed that selective-forwarding be carried out using multiple IP-Multicast groups where each receiver specifies its level of subscription by joining a subset of the groups. In this paper, we extend the multiple group framework with a rate-adaptation protocol called Receiver-driven Layered Multicast, or RLM. Under RLM, multicast receivers adapt to both the static heterogeneity of link bandwidths as well as dynamic variations in network capacity (i.e., congestion). We describe the RLM protocol and evaluate its performance with a preliminary simulation study that characterizes user-perceived quality by assessing loss rates over multiple time scales. For the configurations we simulated, RLM results in good throughput with transient short-term loss rates on the order of a few percent and long-term loss rates on the order of one percent. Finally, we discuss our implementation of a software-based Internet video codec and its integration with RLM.

Recommendations on Queue Management and Congestion Avoidance in the Internet

“…For example, recent research has shown the possibility of incorporating congestion avoidance mechanisms such as Receiverdriven Layered Multicast (RLM) within UDP-based streaming applications such as packet video [McCanne96;Bolot94]. Further research and development on ways to accomplish congestion avoidance for streaming applications will be very important.…”

Performance analysis and modeling of errors and losses over 802.11b LANs for high-bit-rate real-time multimedia

“…In order to provide television-like services, efficient multimedia coding on reliable multicast networks has been an area of active research [11][12][13]. With wireless networks fast becoming ubiquitous, an imperative direction is to tailor future applications and protocols to adapt accordingly.…”

Media aware FEC for Scalable Video Coding transmission

“…Hellge et al proposes to increase the robustness of more important layers by generating protection across layers. This approach is similar to receiver driven layered multicast (RDLM) [7]. Additionally, authors describe an extension of the Raptor FEC code which allows the implementation of a Layered FEC solution.…”