QoS Management: A Model-based Approach

Quality of Service (QoS) management is an important issue in today's high-speed distributed systems supporting multimedia applications. Most existing QoS management schemes usually just cope with technical issues of resource reservations and QoS guarantees, often completely neglecting revenue issues which are especially important for service providers in order to maximize their profit. The revenue to be expected does not only depend on the stream itself, but also very much on stochastic events such as network failures or QoS violations. A QoS management system taking revenue issues and the possibly stochastic behavior of the environment into account thus seems to be superior to the existing ones. In this paper, we show how controller programs for such enhanced QoS management systems can be developed based on a new kind of Petri Nets, so-called Controlled Stochastic Petri Nets. We show how to numerically analyze such models using a tool environment in order to obtain strategies for the QoS management system.