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 a loss differentiation
algorithm (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, competing traffic,
and fairness scenarios. A second goal of this paper is to propose and
evaluate a new loss differentiation algorithm, 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 topology, competition, and fairness scenarios. However, the
hybrid algorithms perform well across topologies, competition, and
fairness, and in some cases match or exceed the performance of the
best base LDA for a given scenario.
