GA-PSO-Optimized Neural-Based Control Scheme for Adaptive Congestion Control to Improve Performance in Multimedia Applications

Active queue control aims to improve the overall communication network throughput while providing lower delay and small packet loss rate. The basic idea is to actively trigger packet dropping (or marking provided by explicit congestion notification (ECN)) before buffer overflow. In this paper, two artificial neural networks (ANN)-based control schemes are proposed for adaptive queue control in TCP communication networks. The structure of these controllers is optimized using genetic algorithm (GA) and the output weights of ANNs are optimized using particle swarm optimization (PSO) algorithm. The controllers are radial bias function (RBF)-based, but to improve the robustness of RBF controller, an error-integral term is added to RBF equation in the second scheme. Experimental results show that GA- PSO-optimized improved RBF (I-RBF) model controls network congestion effectively in terms of link utilization with a low packet loss rate and outperform Drop Tail, proportional-integral (PI), random exponential marking (REM), and adaptive random early detection (ARED) controllers.Comment: arXiv admin note: text overlap with arXiv:1711.0635

Proportional-integral genetic algorithm controller for stability of TCP network

The life development and increase the number of internet users imposed an increase in data circulating on the internet network and then make the network more congestion. As a result of all this, some problems arose such as time delay in packets delivery, loss of packets, and exceed the buffer capacity for the middle routers. To overcome those problems, transmission control protocol and active queue management (TCP/AQM) have been used. AQM is the main approach used to control congestion and overcome those problems to improve network performance. This work proposes to use the proportional-integral (PI) controller with a genetic algorithm (GA) as an active queue manager for routers of the Internet. The simulation results show a good performance for managing the congestion with using proportional-integral genetic algorithm (GA-PI) controller better than the PI controller

On Designing Lyapunov-Krasovskii Based AQM for Routers Supporting TCP Flows

For the last few years, we assist to a growing interest of designing AQM (Active Queue Management) using control theory. In this paper, we focus on the synthesis of an AQM based on the Lyapunov theory for time delay systems. With the help of a recently developed Lyapunov-Krasovskii functional and using a state space representation of a linearized fluid model of TCP, two robust AQMs stabilizing the TCP model are constructed. Notice that our results are constructive and the synthesis problem is reduced to a convex optimization scheme expressed in terms of linear matrix inequalities (LMIs). Finally, an example extracted from the literature and simulations via {\it NS simulator} support our study

Flower Pollination Algorithm to Tune PID Controller of TCP/AQM Wireless Networks

The current study aims to conduct a simulation that is useful in developing an appropriate design that addresses the problem of congestion in the Internet network through controlling the queue of the router. The simulation is conducted through the proposed model for simulation with different control systems that help in raising the quality of performance such as traditional Proportional Integral Derivative (PID) and advanced optimal by Flower Pollination Algorithm  (FPA). It depends for Transmission Control Protocol/ Active Queue Management( TCP/AQM )simulation model for a linear system and another non-linear system. To adjust the network work and raise the level of performance, different control systems were chosen, taking into account all the things that appear through conducting experiments and for different purposes. One of the most important things that must be taken into consideration is the system disturbances as a result of the volume and values of the data, causing congestion . It was shown through the results of the experiments that were conducted considering the cases of the linear and nonlinear system to pass data traffic in the network and by adopting the different techniques of the control units, the preference of optimizasion systems over the traditional ones, as well as the preference of the traditional over  without control in close loop, is the improvement of the performance of linear systems compared to the open and closed system without control. The simulation results showed that very clear the superiority of the optimization by FPA-PID controller over the conventional system (PID)  , as well as very clear the superiority of  the traditional system (PID)over closed system without control and open loop system

Active Queue Management via Event-Driven Feedback Control

Active queue management (AQM) is investigated to avoid incipient congestion in gateways to complement congestion control run by the transport layer protocol such as the TCP. Most existing work on AQM can be categorized as (1) ad-hoc event-driven control and (2) time-driven feedback control approaches based on control theory. Ad hoc event-driven approaches for congestion control, such as RED (random early detection), lack a mathematical model. Thus, it is hard to analyze their dynamics and tune the parameters. Time-driven control theoretic approaches based on solid mathematical models have drawbacks too. As they sample the queue length and run AQM algorithm at every fixed time interval, they may not be adaptive enough to an abrupt load surge. Further, they can be executed unnecessarily often under light loads due to the time-driven nature. To seamlessly integrate the advantages of both event-driven and control-theoretic time-driven approaches, we present an event-driven feedback control approach based on formal control theory. As our approach is based on a mathematical model, its performance is more analyzable and predictable than ad hoc event-driven approaches are. Also, it is more reactive to dynamic load changes due to its event-driven nature. Our simulation results show that our event-driven controller effectively maintains the queue length around the specified set-point. It achieves shorter E2E (end-to-end) delays and smaller E2E delay fluctuations than several existing AQM approaches, which are ad hoc event-driven and based on time-driven control theory, while achieving almost the same E2E delays and E2E delay fluctuations as the two other advanced control theoretic AQM approaches. Further, our AQM algorithm is invoked much less frequently than the tested baseline

HFAQM: A hybrid fair active queue management mechanism to improve fairness and stability for wireless local area network

Active Queue Management (AQM) is a proactive scheme that controls network congestion by avoiding it before it happens. When implementing AQM in wireless networks, several contemporary issues must be considered, such as interference, collisions, multipath-fading, propagation distance and shadowing effects, which affect the transmission rate of the links. These issues in WLAN networks with the existence of different types of flow have a direct effect on fairness. The main idea behind the wireless network is using the flexibility of radio waves to transfer data from point to point that is giving WLAN the flexibility and mobility: wireless nodes can connect, disconnect or even move from one access point to another rapidly. However, this affects the stability of the WLAN network. This research aims to reduce unfairness and instability by proposing a Hybrid-Fair AQM (HFAQM) scheme. HFAQM comprises two mechanisms: Congestion Indicator Mechanism (CIM), and Control Function Mechanism (CFM). CIM was designed to improve fairness in WLANs by hybridizing queue delay with arrival rate as parameters to calculate the congestion level. Whereas, CFM was developed to improve network stability by using an adaptive control function with the ability to drop and mark packets to overcome the rapidly changing characteristics of WLAN network. A series of experimental studies were conducted to validate the proposed mechanisms and four variants of AQM schemes, RED, REM, AVQ and CoDel, were chosen to evaluate the performance of HFAQM through simulation. The findings show that HFAQM’s main achievement is 99% fairness and improved stability by 10% from the closest scheme, with better throughput, queue length, queue loss, and outgoing link utilization as secondary achievements. The proposed scheme provides significantly better fairness and stability in WLAN environment, with the existence of different types of flow

A new PI and PID control design method and its application to active queue management of TCP flows

Cataloged from PDF version of article.PID controllers are continuing to be used in many control applications due to their simple structures. Design of such controllers for unstable systems with time delays is an active research area. Recently, stabilizing PI and PD controllers for a class of unstable MIMO (multi-input multi-output) systems with input/output delays have been investigated and allowable controller gain intervals for such controllers have been maximized. Motivated by these studies, this thesis proposes a new method for tuning the parameters of PI, PD and PID controllers for integrating processes with time delays. The method is based on selecting the centers of the maximized gain intervals as the controller gains for the purpose of obtaining optimal controllers. As an application of this method, controllers for AQM (Active Queue Management) of TCP (Transmission Control Protocol) flows have been designed. AQM is a congestion control method used in computer networks to increase link utilization with less queueing delays. The fluid flow model of TCP’s congestion avoidance mode based on delay differential equations supplies the mathematical background for modelling the AQM as a feedback control system and designing different control schemes accordingly. Firstly, the proposed controller design method has been applied to AQM for the case of time invariant time delay and secondly the method has been supported with switching control technique to obtain optimum system performance in the case of time varying time delay. The performance of the designed controllers for both cases has been illustrated by packet level simulations in ns-2.Üstebay, DenizM.S

Switching resilient PI controllers for active queue management of TCP flows

Active Queue Management (AQM) is used in computer networks to increase link utilization with less queueing delays. The fluid flow model or TCP based on delay differential equations supplies the mathematical background for modelling the AQM as a feedback system. Recently various PI and PID controllers arr designed for this feedback system, [7], [18]. In this paper, we consider the case for which the Round Trip Time (RTT) is time varying and we propose switching resilient PI controllers using the design method introduced in [18]. © 2007 IEEE