Adaptive QoS in Multimedia Systems

Abstract

We propose the introduction of an abstract concept of QoS to all layers of the multimedia software architecture. Each layer in a software system deals with QoS at its appropriate level of abstraction using a generic API for communicating QoS parameters and values to layers above and below. We call the aggregation of these parameters and values a "service contract". By mapping the contract at one layer to other contracts at the layer below we can build service hierarchies that allow the design of adaptive systems based on a single framework. Further the API allows for reporting of contract violations as well as dynamic renegotiations of the contract terms.To verify these ideas we built a proof-of-concept multimedia system (Ott, 1997) which showed that our architecture is not only feasible but offers a powerful framework for building adaptive multimedia systems.

A Scalable Pricing Model for Bandwidth Allocation

“…Instead of buffering to limit the fluctuations in bandwidth we use the users' requirements as a low-high bandwidth range. Ott et al [10] allow the QoS to be specified at the CPU level, the network resources level or in the form of user satisfaction by adding QoS parameters to standard system calls. But this does not relate the QoS to pricing.…”