scholarly journals ANALYSIS AND CONTROL OF BIFURCATION AND CHAOS IN AVERAGE QUEUE LENGTH IN TCP/RED MODEL

2008 ◽  
Vol 18 (08) ◽  
pp. 2449-2459 ◽  
Author(s):  
J. H. C. NGA ◽  
H. H. C. IU ◽  
B. W. K. LING ◽  
H. K. LAM
Keyword(s):  
Bifurcation Analysis ◽  
Queue Length ◽  
Network Performance ◽  
Transmission Control Protocol ◽  
Nonlinear Behavior ◽  
Random Early Detection ◽  
Network Systems ◽  
Bifurcation And Chaos ◽  
Queuing Delay ◽  
And Control

This paper studies the bifurcation and chaos phenomena in average queue length in a developed Transmission Control Protocol (TCP) model with Random Early Detection (RED) mechanism. Bifurcation and chaos phenomena are nonlinear behavior in network systems that lead to degradation of the network performance. The TCP/RED model used is a model validated previously. In our study, only the average queue size [Formula: see text] is considered, and the results are based on analytical model rather than actual measurements. The instabilities in the model are studied numerically using the conventional nonlinear bifurcation analysis. Extending from this bifurcation analysis, a modified RED algorithm is derived to prevent the observed bifurcation and chaos regardless of the selected parameters. Our modification is for the simple scenario of a single RED router carrying only TCP traffic. The algorithm neither compromises the throughput nor the average queuing delay of the system.

scholarly journals Weight Queue Dynamic Active Queue Management Algorithm

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2077
Author(s):  
Mahmoud Baklizi
Keyword(s):  
Queue Length ◽  
Network Performance ◽  
Active Queue Management ◽  
Traffic Load ◽  
Dynamic Monitoring ◽  
Queue Management ◽  
Queuing Delay ◽  
Management Algorithm ◽  
Mean Queue Length ◽  
Management Algorithms

The current problem of packets generation and transformation around the world is router congestion, which then leads to a decline in the network performance in term of queuing delay (D) and packet loss (PL). The existing active queue management (AQM) algorithms do not optimize the network performance because these algorithms use static techniques for detecting and reacting to congestion at the router buffer. In this paper, a weight queue active queue management (WQDAQM) based on dynamic monitoring and reacting is proposed. Queue weight and the thresholds are dynamically adjusted based on the traffic load. WQDAQM controls the queue within the router buffer by stabilizing the queue weight between two thresholds dynamically. The WQDAQM algorithm is simulated and compared with the existing active queue management algorithms. The results reveal that the proposed method demonstrates better performance in terms mean queue length, D, PL, and dropping probability, compared to gentle random early detection (GRED), dynamic GRED, and stabilized dynamic GRED in both heavy or no-congestion cases. In detail, in a heavy congestion status, the proposed algorithm overperformed dynamic GRED (DGRED) by 13.3%, GRED by 19.2%, stabilized dynamic GRED (SDGRED) by 6.7% in term of mean queue length (mql). In terms of D in a heavy congestion status, the proposed algorithm overperformed DGRED by 13.3%, GRED by 19.3%, SDGRED by 6.3%. As for PL, the proposed algorithm overperformed DGRED by 15.5%, SDGRED by 19.8%, GRED by 86.3% in term of PL.

IGRED: An Improved Gentle Random Early Detection Method for Management of Congested Networks

2019 ◽  
Vol 19 (02) ◽  
pp. 1950004
Author(s):  
HUSSEIN ABDEL-JABER ◽  
ABDULAZIZ SHEHAB ◽  
MOHAMED BARAKAT ◽  
MAGDI RASHAD
Keyword(s):  
Early Detection ◽  
Queue Length ◽  
Detection Method ◽  
Random Early Detection ◽  
Queuing Delay ◽  
Packet Dropping ◽  
Dropping Probability ◽  
Maximum Value ◽  
Congested Networks ◽  
Mean Queue Length

Controlling congested router buffers of a network has a crucial role in improving network’s performance. This paper proposes a novel Active Queue Management (AQM) method named Improved Gentle Random Early Detection (IGRED) that based on GRED algorithm, which counted as one of the popular AQM methods. The proposed is mainly developed to overcome the problems faced with classic GRED. The initial packet-dropping probability depends on several parameters such as the average queue length, maximum value of packet dropping probability, minimum and maximum thresholds, etc. IGRED reduces its reliance on the GRED’s parameters through shrinking these parameters. The results shows, when congestion is taken place, the proposed IGRED provides more satisfactory performance with reference to mean queue length, average queuing delay, and overflow packet loss probability.

Development of a Jacobian Module for Advanced Pulp and Paper Simulation and Control

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 4-11
Author(s):  
MOHAMED CHBEL ◽  
LUC LAPERRIÈRE
Keyword(s):  
Control System ◽  
Nonlinear Behavior ◽  
Simulation Software ◽  
Pulp And Paper ◽  
Pid Controllers ◽  
Tuning Parameters ◽  
Pid Tuning ◽  
Fixed Set ◽  
And Control ◽  
Operating Points

Pulp and paper processes frequently present nonlinear behavior, which means that process dynam-ics change with the operating points. These nonlinearities can challenge process control. PID controllers are the most popular controllers because they are simple and robust. However, a fixed set of PID tuning parameters is gen-erally not sufficient to optimize control of the process. Problems related to nonlinearities such as sluggish or oscilla-tory response can arise in different operating regions. Gain scheduling is a potential solution. In processes with mul-tiple control objectives, the control strategy must further evaluate loop interactions to decide on the pairing of manipulated and controlled variables that minimize the effect of such interactions and hence, optimize controller’s performance and stability. Using the CADSIM Plus™ commercial simulation software, we developed a Jacobian sim-ulation module that enables automatic bumps on the manipulated variables to calculate process gains at different operating points. These gains can be used in controller tuning. The module also enables the control system designer to evaluate loop interactions in a multivariable control system by calculating the Relative Gain Array (RGA) matrix, of which the Jacobian is an essential part.

Compensation of the Nonlinear Effect on Anelectro Hydrostatic Cylinder Driver for the Transit and Rotating Motion Using Bilinear System

2014 ◽  
Vol 875-877 ◽  
pp. 2097-2106
Author(s):  
Rai Wung Park
Keyword(s):  
High Performance ◽  
Nonlinear Behavior ◽  
Bilinear System ◽  
Mathematic Model ◽  
Modeling And Control ◽  
Extended Application ◽  
Physical Information ◽  
Complete Form ◽  
And Control ◽  
Operating Points

The transit motion and the rotating motion have highly different effects in a technical systems and have almost nonlinear system behaviors. For the descriptions of their dynamical causes and effects on system, the physical information, which is concerned as a nonlinear mathematic model, has been used. But the corresponding equations are generally not easy to solve in complete form or their solutions are so complicated to see through the coherence. A common way to settle such a problem is to linearize system exactly in a state space or on a operating points with Taylor's series approximately. An advanced method to an approximation is a bilinear system that offers global separations principle. In this paper, an extended application of this theory is given in a modeling and control on the electro hydrostatic cylinder driver with both the transit and rotating motions for the keel system that mostly have not only advantage of high performance, small volume of building and weight but also high nonlinear behavior.

Performance and control of network systems

2001 ◽  
Vol 43 (4) ◽  
pp. 201-202
Author(s):  
Robert D. van der Mei ◽  
Daniel P. Heyman
Keyword(s):  
Network Systems ◽  
And Control

Conclusion

2011 ◽  
Author(s):  
Wassim M. Haddad ◽  
Sergey G. Nersesov
Keyword(s):  
Dynamical Systems ◽  
Large Scale ◽  
Multiple Equilibria ◽  
Nonlinear Models ◽  
Dynamical Behavior ◽  
Transportation Systems ◽  
Network Systems ◽  
Grid Systems ◽  
Feedback Interconnections ◽  
And Control

This book has described a general stability analysis and control design framework for large-scale dynamical systems, with an emphasis on vector Lyapunov function methods, vector dissipativity theory, and decentralized control architectures. The large-scale dynamical systems are composed of interconnected subsystems whose relationships are often circular, giving rise to feedback interconnections. This leads to nonlinear models that can exhibit rich dynamical behavior, such as multiple equilibria, limit cycles, bifurcations, jump resonance phenomena, and chaos. The book concludes by discussing the potential for applying and extending the results across disciplines, such as economic systems, network systems, computer networks, telecommunication systems, power grid systems, and road, rail, air, and space transportation systems.

Random Early Discard (RED) Queue Evaluation for Congestion Control

2012 ◽  
pp. 229-246
Author(s):  
Md. Shohidul Islam ◽  
Md. Niaz Morshed ◽  
Sk. Shariful Islam ◽  
Md. Mejbahul Azam
Keyword(s):  
Congestion Control ◽  
Performance Optimization ◽  
Transmission Control Protocol ◽  
Active Queue Management ◽  
Queue Management ◽  
Transmission Control ◽  
Control Protocol ◽  
Network Parameters ◽  
Internet Performance ◽  
And Control

Congestion is an un-avoiding issue of networking, and many attempts and mechanisms have been devised to avoid and control congestion in diverse ways. Random Early Discard (RED) is one of such type of algorithm that applies the techniques of Active Queue Management (AQM) to prevent and control congestion and to provide a range of Internet performance facilities. In this chapter, performance of RED algorithm has been measured from different point of views. RED works with Transmission Control Protocol (TCP), and since TCP has several variants, the authors investigated which versions of TCP behave well with RED in terms of few network parameters. Also, performance of RED has been compared with its counterpart Drop Tail algorithm. These statistics are immensely necessary to select the best protocol for Internet performance optimization.

scholarly journals Model Reduction Methods for Complex Network Systems

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
X. Cheng ◽  
J.M.A. Scherpen
Keyword(s):  
Autonomous Systems ◽  
High Dimensional ◽  
Annual Review ◽  
Publication Date ◽  
Network Systems ◽  
Modeling And Control ◽  
Reduced Order ◽  
Reduction Methods ◽  
The Stability ◽  
And Control

Network systems consist of subsystems and their interconnections and provide a powerful framework for the analysis, modeling, and control of complex systems. However, subsystems may have high-dimensional dynamics and a large number of complex interconnections, and it is therefore relevant to study reduction methods for network systems. Here, we provide an overview of reduction methods for both the topological (interconnection) structure of a network and the dynamics of the nodes while preserving structural properties of the network. We first review topological complexity reduction methods based on graph clustering and aggregation, producing a reduced-order network model. Next, we consider reduction of the nodal dynamics using extensions of classical methods while preserving the stability and synchronization properties. Finally, we present a structure-preserving generalized balancing method for simultaneously simplifying the topological structure and the order of the nodal dynamics. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 4 is May 3, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Sign in / Sign up

Export Citation Format

Share Document