Analysis of admission control mechanisms using non-linear control theory

All service control nodes can be modelled as a server system with one or more servers processing incoming requests. In this paper we show how non-linear control theory may be used when analyzing admission control mechanisms for server systems. Two models are developed, one linear and one non-linear. We show that, due to the non-linearities appearing in a real server system, linear control theory is sufficient when designing controllers for these systems. With non-linear analysis, however, the dynamics of a server system may be analysed and taken care of by choosing the controller parameters appropriately.