An LMI Approach to Robust Control of Packet Loss Probability
Dongli Zhang, Dan Dominic Ionescu · 2006
Provisioning QoS enabled VPN services over packet switched networks is increasingly important for service providers. Previous works propose a dynamic packet loss control system that maintains preset packet loss targets for the instantiated VPN services in the provider's backbone network. In the control system, the transducer and dynamic model have been studied. However, the identified linear model contains time-varying norm-bounded uncertain parameters. This paper extends the previous research and designs a robust controller. Specifically, the classical controller is first designed. A linear matrix inequality (LMI) approach for designing the robust proportional-integral (PI) controller is then studied. By adopting the LMI expression, a symmetric positive definite matrix P with guaranteed overall system's quadratic stability is determined. The matrix P finally infers the robust PI controller parameters. Through a number of experiments, the transient and steady state performance of the controller-is evaluated on the live NCIT*net network