Delay-Based Non-linear Observers for Congestion Control in Communication Networks

Abstract

The purpose of this contribution is to investigate the construction and use of delay-based observers in communication networks, starting from a state-space model of an elementary network configuration. This work is a step towards the design of a source-rate congestion and delay control algorithm adapted to applications with real-time constraints, such as video streaming. Our ultimate aim is to design an “end to end” control scheme implemented at source level, using only feedback information from the destinations transmitted through the network as part of the general “best effort” data stream, and which could therefore be deployed on essentially every existing network infrastructure, especially those ruled by the Internet Protocol. Obviously, observer-based control structures provide an appropriate conceptual framework to deal with such measurement constraints. In this particular application, we propose to combine a linear state-feedback plus disturbance feedforward control with a non-linear observer of network congestion fed with measurements of source-to-destination transmission delay.