23,544 research outputs found
Design and performance evaluation of a state-space based AQM
Recent research has shown the link between congestion control in
communication networks and feedback control system. In this paper, the design
of an active queue management (AQM) which can be viewed as a controller, is
considered. Based on a state space representation of a linearized fluid flow
model of TCP, the AQM design is converted to a state feedback synthesis problem
for time delay systems. Finally, an example extracted from the literature and
simulations via a network simulator NS (under cross traffic conditions) support
our study
Robust control tools for traffic monitoring in TCP/AQM networks
Several studies have considered control theory tools for traffic control in
communication networks, as for example the congestion control issue in IP
(Internet Protocol) routers. In this paper, we propose to design a linear
observer for time-delay systems to address the traffic monitoring issue in
TCP/AQM (Transmission Control Protocol/Active Queue Management) networks. Due
to several propagation delays and the queueing delay, the set TCP/AQM is
modeled as a multiple delayed system of a particular form. Hence, appropriate
robust control tools as quadratic separation are adopted to construct a delay
dependent observer for TCP flows estimation. Note that, the developed mechanism
enables also the anomaly detection issue for a class of DoS (Denial of Service)
attacks. At last, simulations via the network simulator NS-2 and an emulation
experiment validate the proposed methodology
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