We introduce a novel and robust active queue management (AQM) scheme based on a fuzzy controller, called hybrid fuzzy-PID controller. In the TCP network, AQM is important to regulate the queue length by passing or dropping the packets at the intermediate routers. RED, PI, and PID algorithms have been used for AQM. But these algorithms show weaknesses in the detection and control of congestion u...

To cope with computing power limitations, air quality models that are used in integrated assessment applications are generally approximated by simpler expressions referred to as "source-receptor relationships (SRR)". In addition to speed, it is desirable for the SRR also to be spatially flexible (application over a wide range of situations) and to require a "light setup" (based on a limited num...

For TCP/AQM systems, the issue of buffer sizing has recently received much attention. The classical rule-of-thumb suggests O(N) buffer size to ensure full link utilization when N TCP flows share a bottleneck link of capacity O(N), while recent empirical study shows the buffer of size O( √ N) is enough to yield high utilization (say, 95%) for large N . However, these results are all limited to t...

The algorithms of queue management in IP routers determine which packet should be deleted when necessary. The active queue management, recommended by IETF, enhances the efficiency of transfers and cooperate with TCP congestion window mechanism in adapting the flows intensity to the congestion of a network. The article investigates the influence of the way of choosing packets to be dropped (end ...

In a potentially congested network, random early detection (RED) active queue management (AQM) proved effective in improving throughput and average queuing delay. The main disadvantage of RED is its sensitive parameters that are impossible to estimate perfectly and adjust manually because of the dynamic nature of the network. For this reason, RED performs differently during different phases of ...

Active Queue Management (AQM) is intended to achieve high link utilization with a low queuing delay. Recent studies show that RED, one of the most well-known AQMs, is difficult to configure and does not provide significant performance gains given the complexity required for proper configuration. Recent variants of RED, such as Adaptive-RED are designed to provide more robust RED performance und...

We present a non-equilibrium analysis and control approach for the Active Queue Management (AQM) problem in communication networks. Using simplified fluid models we carry out a bifurcation study of the complex dynamic queue behavior to show that non-equilibrium methods are essential for analysis and optimization in the AQM problem. We investigate an ergodic theoretic framework for stochastic mo...

Routers are vital during network congestion. All routers have input and output packet buffers. V<span lang="EN-US">Various congestion control strategies been suggested. Some controller-based proportional-integral derivative (PIDs) recently offered as active queue management (AQM) solutions to alleviate the deterioration of transmission protocol (TCP) system performance. However, time dela...

The conceptual shift in the expectations of the wireless users from voice towards multimedia, from availability towards acceptable quality, and from stand-alone towards group-oriented computing has a significant impact on today’s networks in terms of the need for mobility, quality of service (QoS) and multicasting. Ad hoc networks, being independent of any fixed infrastructure, can provide mobi...

Active queue management (AQM) algorithms are useful not only for congestion avoidance purposes, but also for the differentiated forwarding of packets, as is done in the DiffServ architecture. It is well known that correctly setting the parameters of an AQM algorithm may prove difficult and error-prone. Besides, many studies have shown that the performance of AQM mechanisms is very sensitive to ...