R. Agrawal, R. L. Cruz, C. Okino, and R. Rajan, "A Framework for Adaptive Service Guarantees,"
Proceedings of the 36th Allerton Conference on
Communication, Control, & Computing, Monticello, IL, September, 1998.
Full paper (547K,postscript).
Recently, a mathematical framework has been developed for the
provision of deterministic quality of service guarantees in
integrated services networks. This framework, or so-called
"network calculus," involves the concepts of
traffic envelopes, service curves, and convolution in the
min-plus alegebra. Traffic envelopes
constrain arrival processes, while service curves constrain the
input-output behavior of network elements. Upper bounds on
network delay are implied by the distance between a traffic envelope
and service curve.
In this paper, we develop a somewhat parallel framework for the
provision of deterministic
quality of service guarantees to adaptive applications.
Adaptive applications generate
a traffic load that is dependent on network utilization,
and thus characterizing the
traffic generated from an adaptive application with
an envelope is problematic.
We introduce an adaptive service definition, through which
upper bounds on network delay
can be derived without using a traffic envelope.
Instead, upper bounds on network delay are obtained in terms of
the backlog and an absolute service
curve. Since the backlog can be controlled
through feedback, e.g. through window flow control,
this yields a mechanism to obtain upper bounds on network delay.
Lower bounds on network throughput are also implied through
an absolute service curve.