14th IFAC Symposium on System Identification, SYSID 2006

SYSID-2006 Paper Abstract


Paper ThB4.2

Jacobsson, Krister (KTH), Hjalmarsson, Håkan (KTH)

Closed Loop Aspects of Fluid Flow Model Identification in Congestion Control

Scheduled for presentation during the Regular Session "Closed Loop Identification" (ThB4), Thursday, March 30, 2006, 15:50−16:10, Cummings Room

14th IFAC Symposium on System Identification, March 29 - 31, 2006, Newcastle, Australia

This information is tentative and subject to change. Compiled on September 24, 2018

Keywords Closed Loop Identification, Model Validation, Other


Fluid flow models have turned out to be instrumental for analysis and synthesis of primal/dual congestion control algorithms which rely on aggregated information from a network path. In particular stability has been analyzed using such models. In network congestion control, validation experiments will with necessity be performed in closed loop since the communication protocol has to be active. Guidelines on how such experiments should be carried out in practice has until now been lacking in the literature. Departing from the theory of modeling for control, we refine a fluid flow model by augmenting the customary model of transport latencies, link price and source control with estimator dynamics and sampling properties. The impact of cross-traffic and changes in network configuration is incorporated as well. Furthermore, we analyze, from a closed-loop perspective, how the network should be excited when validating such models. The resulting identification framework is used for validating the derived model using packet-level experimental data from NS-2 simulations.