End-to-end differentiation of congestion and wireless losses

摘要

In this paper, we explore end-to-end loss differentiation algorithms (LDAs) for use with congestion-sensitive video transport protocols for networks with either backbone or last-hop wireless links. As our basic video transport protocol, we use UDP in conjunction with a congestion control mechanism extended with an LDA. For congestion control, we use the TCP-Friendly Rate Control (TFRC) algorithm. We extend TFRC to use an LDA when a connection uses at least one wireless link in the path between the sender and receiver. One goal of this paper is to evaluate various LDAs under different wireless network topologies and competing traffic. A second goal of this paper is to propose and evaluate a new LDA, called ZigZag, as well as a class of hybrid algorithms based upon ZigZag. We then evaluate these LDAs via simulation. Based upon our simulation results, we find that no single base algorithm performs well across all topologies and competition. However, the hybrid algorithms perform well across topologies, competition, and in some cases match or exceed the performance of the best base LDA for a given scenario.