Effective Congestion Control Research Articles

The comparison of network congestion avoidance algorithms in data exchange networks.

Effective congestion control strategies allow in maintaining low delay and high throughput in data exchange networks. These requirements seem to be the most desired by network environment participants. Wide range of algorithms are proposed in the literature to approximate to these ideal parameters. All of these approaches are focused on alleviating the results of sudden, unexpected network state changes. This paper discuss a comparison of four control strategies, focused on congestion avoidance. All of them are in charge of queue length control in active network nodes. For research purpose, non-stationary, discrete, dynamical model of communication channel has been used. Research results are presented in table and chart form.

Effective Internet Traffic Management by Reducing Congestion in TCP Cubic through Proactive Approach

The future of modern Internet is adapting Cloud Computing, IoT and 3D technology over the Internet. So, Internet needs to exchange a huge amount of information in the form of packets of requests, responses and controlling data. An Internet connection always has finite throughput and can only support certain number of packets at a time. Transferring too many packets on Internet connection can produce heavy Internet Traffic which may cause bottleneck or network congestion. Meanwhile, the operations between the communication devices also effect and slow down. Effective congestion control is one of the most critical issues in the efficiency of Internet Traffic Management. To make it sustainable and efficient, a systematic approach to planning, testing and maintaining its behavioral mechanism is desirable to avoid network congestion and keep the data flowing smoothly. In this area of traffic management, the research will be conducted on different TCP variants and proposed a model of congestion avoidance. The new Congestion Avoidance algorithmic model will enhance the performance and utilization of the network, by making TCP more flexible and efficient protocol with a new proactive approach. The results of analysis will help the industrial developers and researchers to implement the proposed solution in Linux Kernel for more stable version of TCP.

Research on Self-adaptive TFRC Congestion Control of Streaming Media in Wireless Network

Transport layer protocol, for lack of effective congestion control, made an irrational bandwidth utilization ratio between UDP and TCP. Especially for streaming media transport which is easily to cause the network congestion. TFRC (TCP-friendly rate control protocol) congestion control mechanism had solved the problem effectively. However, in the high bit error rate environment of wireless network, TFPC would mistake the bit error for congestion lost packet that degrades throughput excessively. Concerning this issue, this paper put forward a self-adaptive TFRC mechanism which distinguishes congest and bit error effectively by distinguishing parameters, and adjusts the transmission rate dynamically. Simulation result reveals that self-adaptive TFRC mechanism can use link efficiently, reduce delay variation and meet the live transmission requirement of streaming media in wireless network.

Fast fairness convergence through fair rate estimation in Variable-structure congestion Control Protocol

Traditional Transmission Control Protocol (TCP) faces significant limitations such as unclear congestion implication, low utilization in high-speed networks, unstable throughput and limited fairness. In order to overcome such limitations, numerous research works have been done in effective congestion control algorithms. Among these, Variable-structure congestion Control Protocol (VCP) leverages only the existing two explicit congestion notification bits for network congestion feedback, yet achieves high utilization, low persistent queue length, negligible packet loss rate and reasonable fairness. However, VCP converges to fairness relatively slowly due to its large multiplicative decrease parameter. To address this problem, we propose an end-host based method for fast fairness convergence, namely VCP-FFC (VCP with fast fairness convergence). In each Additive Increase and Multiplicative Decrease (AIMD) epoch, VCP-FFC estimates a fair rate in end-hosts, and adjusts the congestion window according to the fair rate to achieve fast fairness convergence. We evaluate the performance of VCP-FFC over a wide range of network scenarios using NS2. Simulation Results show that VCP-FFC not only maintains the good properties of VCP, but also significantly accelerates fairness convergence. Dynamic analysis shows that VCP-FFC is asymptotically stable and converges to a unique stationary point, i.e. the fair rate share.

On Markovian Modeling of Vehicular Traffic Flow in Gwagwalada Metropolis, Nigeria.

Analysis of queue performance parameters is inevitable for efficient and effective congestion control and traffic free networking system. This study assesses the efficiency and effectiveness of road traffic systems, using the Atlas Hotel road intersection, Gwagwalada, Abuja Nigeria as a case study. Queue theory analytic methodologies are applied and parameters such as average arrival and service rate are calculated based on the data obtained at the said junction on daily basis for a period of one week. Inter-arrival time is 10 seconds and M/M/3 queue model was found appropriate. Considering the 15278 vehicles observed, major arrivals and departure were on the SDP leg, while the least arrivals and departure was witnessed on the Town-Hall leg, the El-Rufai and NITEL legs had varying degrees of arrivals and departure. Based on the data gathered, it was observed that the evenings record the highest magnitude of vehicular traffic at the intersection while mornings had the least. It was concluded that with reference to the intersection studied, road traffic system performance within the Gwagwalada metropolis is stable as Level of Service is A with Average Control Delay(seconds/vehicle) . Modernization and re-design of roadways, traffic education, as well as introduction of road traffic utilities were recommended.

Modeling of Congestion and Traffic Control Techniques in ATM Networks

In this Paper, Computer – based Simulation models for effective Congestion control and Traffic management in Asynchronous Transfer Mode (ATM) network have been developed providing a basis for monitoring ATM networks performance for traffic and congestion control purposes ,providing a system with a reduce short -term congestion in ATM networks, and enhancing a fair operation of networks in spite of the challenges in designing ATM traffic management system to make maximal use of network resources. An IDCC scheme was implemented, applying IDCC methodology to the ATM Network. Using analysis performance, limits were created for robust controlled network behaviour, as dictated by reference values of the desired queue length. By tightly controlling output of the controller, the overall network performance was adjusted and also controlled. A simulation tool, MATLAB/SIMULINK, was used for this purpose. An improvement was observed in the delay performance of ATM networks. The results were obtained by running several simulations and populating a table with the outcome over a number of simulation runs. The effectiveness of the congestion control techniques was tested by analysing the dynamic performance of the model through variation of some parameters. The performance of this model proved to be efficient if applied in the ATM network of today.

Energy Effective Congestion Control for Multicast with Network Coding in Wireless Ad Hoc Network

In order to improve network throughput and reduce energy consumption, we propose in this paper a cross-layer optimization design that is able to achieve multicast utility maximization and energy consumption minimization. The joint optimization of congestion control and power allocation is formulated to be a nonlinear nonconvex problem. Using dual decomposition, a distributed optimization algorithm is proposed to avoid the congestion by control flow rate at the source node and eliminate the bottleneck by allocating the power at the intermediate node. Simulation results show that the cross-layer algorithm can increase network performance, reduce the energy consumption of wireless nodes and prolong the network lifetime, while keeping network throughput basically unchanged.

A Fault Tolerant Congestion Aware Routing Protocol for Mobile Adhoc Networks

Problem statement: The performance of ad hoc routing protocols will si gnificantly degrade when there are faulty nodes in the network. Packet losses and bandwidth degradation are caused due to congestion and thus, time and energy is wasted during its recovery. The fault tolerant congestion aware routing protocol addresses these p roblems by exploring the network redundancy through multipath routing. Approach: In this study, it is proposed to design a fault to lerant congestion aware multi path routing protocol to reduce the rou te breakages and congestion losses. The AOMDV protocol is used as a base for the multipath routin g. This proposed scheme enables more nodes to salvage a dropped packet. Results: Simulation results show that the proposed protocol achieves better throughput and packet delivery ratio with reduced d elay, packet drop and energy. Conclusion: An effective congestion control technique proposed in this study proactively detects node level and link level congestion and performs congestion control us ing the fault-tolerant multiple paths.

Intelligent Control of Congestion Based on Multi-SoftMan

Low performance and unfairness existed in current congestion control, meanwhile network is growing rapidly. It needs a new effective congestion control to meet expanded demands and improve actual state. As a new technique framework, SoftMan is proposed with its intelligence, autonomy and initiative to bring a new idea for information system. The paper looks not only at the benefits derived from intelligence, but also at those associated with Multi-SoftMan alliance in general. After exploring these benefits, an intelligent control model of congestion control based on multi-SoftMan is proposed. At the same time, the paper visualizes the architecture and system behaviors of Multi-SoftMan intelligent congestion control system (MSMICC).

A Simple but Effective Congestion Control Scheme for Safety-Related Events in VANET

A Simple but Effective Congestion Control Scheme for Safety-Related Events in VANET

Design of Active Queue Management for Robust Control on Access Router for Heterogeneous Networks

The Internet architecture is a packet switching technology that allows dynamic sharing of bandwidth among different flows with in an IP network. Packets are stored and forwarded from one node to the next until reaching their destination. Major issues in this integration are congestion control and how to meet different quality of service requirements associated with various services. In other words streaming media quality degrades with increased packet delay and jitter caused by network congestion. To mitigate the impact of network congestion, various techniques have been used to improve multimedia quality and one of those techniques is Active Queue Management (AQM). Access routers require a buffer to hold packets during times of congestion. A large buffer can absorb the bursty arrivals, and this tends to increase the link utilizations but results in higher queuing delays. Traffic burstiness has a considerable negative impact on network performance. AQM is now considered an effective congestion control mechanism for enhancing transport protocol performance over wireless links. In order to have good link utilization, it is necessary for queues to adapt to varying traffic loads. This paper considers a particular scheme which is called Adaptive AQM (AAQM) and studies its performance in the presence of feedback delays and its ability to maintain a small queue length as well as its robustness in the presence of traffic burstiness. The paper also presents a method based on the well-known Markov Modulated Poisson Process (MPP) to capture traffic burstiness and buffer occupancy. To demonstrate the generality of the presented method, an analytic model is described and verified by extensive simulations of different adaptive AQM algorithms. The analysis and simulations show that AAQM outperforms the other AQMs with respect to responsiveness and robustness.

Queueing and Service Patterns in a University Teaching Hospital

Analysis of queueing and service times is essential for designing effective congestion control at a service point. The objective of this is to be able to offer satisfactory service to waiting customers with minimum delay. In this study, using University of Abuja Teaching Hospital as a case study, we compared the queueing and service patterns in major key service departments of the hospital. Analysis of the data gathered showed that arrival and departure times follow Poison distribution with the M/M/I queueing model. Results from data analysis show that service delay which leads to long queue occur mostly at the consultancy department, followed by the pharmacy department. Very little or no delay at all occur at the records department.

Impact of AQM scheme on WLANs using queue thresholds

Explosive growth of applications for wireless networks and increasing number of users will cause significant increase in the traffic over radio channels. Consequently, uplink and downlink channels may suffer serious traffic congestion problems in the absence of effective congestion control schemes. One approach to enhance the performance of wireless services is to employ an AQM scheme for buffers at the downlink of wireless networks. This paper presents an analytical framework for the performance evaluation of AQM scheme based congestion control mechanism in WLANs. It also carries out a comprehensive performance comparison for various dropping strategies to see the impact of AQM scheme on WLANs using queue thresholds.

Stochastic Congestion Control in Wireless Sensor Networks

In this paper, an effective congestion control algorithm is proposed to increase the end-to-end delivery success ratio of upstream traffic by reduction of buffer drop probabilities and their deviation in wireless sensor networks. According to the queue length of parent and child nodes, each child node chooses one of the parents as the next hop to the sink and controls the delay before transmission begins. It balances traffics among parents and mitigates congestion based on congestion level of a node. Simulation results show that the proposed algorithm reduces buffer drop probabilities and their deviation and increases the end-to-end delivery success ratio in wireless sensor networks.

SVC-based scalable multiple description video coding and optimization of encoding configuration

It is well known that multiple multicast trees can avoid single point of failures in peer-to-peer (P2P) streaming originating from a single source by providing path diversity. Multiple description video coding is well suited for serving video over multiple multicast trees, such that each description can be streamed over a different tree. In scalable multiple description coding (SMDC), each description is scalable coded (e.g., derived from a single scalable video coding (SVC)-compliant bitstream) so that descriptions can be efficiently adapted to the available rate of each link for effective congestion control. This paper proposes (i) new SMDC generation methods based on various combinations of video segments (GOPs or fames) coded at high and low rates (one or more layers) and (ii) a multiple-objective optimization (MOO) framework for selection of the best encoding configuration of the proposed SMDC from a set of candidates in order to achieve the best tradeoff between redundancy and reliability (measured by end-to-end rate-distortion performance over a range of extraction points for a set of packet loss probabilities), while maximizing the range of extraction points of each scalable description. The optimization is performed over selected SVC encoding parameters and MD generation alternatives that feature various levels of redundancy at a fixed total rate for all descriptions. The framework is generic to allow optimization over other SVC encoding variables and MD generation methods, or just over the SVC encoding variables without MD, if desired. Results of Monte-Carlo simulation of SMDC streaming with two descriptions over two paths with packet losses are provided to demonstrate performance of the proposed methods.

A collision-free MAC scheme for multimedia wireless mesh backbone

Wireless mesh networking is a promising wireless technology for future broadband Internet access. In this paper, a novel collision-free medium access control (MAC) scheme supporting multimedia applications is proposed for wireless mesh backbone. The proposed scheme is distributed, simple, and scalable. Benefiting from the fixed locations of wireless routers, the proposed MAC scheme reduces the control overhead greatly as compared with conventional contention-based MAC schemes (e.g., IEEE 802.11). In addition, the proposed scheme can provide guaranteed priority access to real-time traffic and, at the same time, ensure fair channel access to the routers with data traffic. Unlike most of the existing MAC schemes which focus on single-hop transmissions, the proposed MAC scheme takes the intra-flow correlations between up-stream and downstream hops of a multi-hop flow into consideration. To avoid buffer overflow at bottleneck routers, a simple but effective congestion control mechanism is proposed. Simulation results demonstrate that the proposed scheme significantly improves the delay performance of real-time traffic and the end-to-end data throughput, as compared with IEEE 802.11 and distributed packet reservation multiple access (DPRMA). The performance analysis of the proposed scheme is also presented. The accuracy of the analytical results is verified by computer simulations.

Road pricing for congestion control with unknown demand and cost functions

It is widely recognized that precise estimation of road tolls for various pricing schemes requires a few pieces of information such as origin–destination demand functions, link travel time functions and users’ valuations of travel time savings, which are, however, not all readily available in practice. To circumvent this difficulty, we develop a convergent trial-and-error implementation method for a particular pricing scheme for effective congestion control when both the link travel time functions and demand functions are unknown. The congestion control problem of interest is also known as the traffic restraint and road pricing problem, which aims at finding a set of effective link toll patterns to reduce link flows to below a desirable target level. For the generalized traffic equilibrium problem formulated as variational inequalities, we propose an iterative two-stage approach with a self-adaptive step size to update the link toll pattern based on the observed link flows and given flow restraint levels. Link travel time and demand functions and users’ value of time are not needed. The convergence of the iterative toll adjustment algorithm is established theoretically and demonstrated on a set of numerical examples.

Effective RED: An algorithm to improve RED's performance by reducing packet loss rate

Random early detection (RED) is an effective congestion control mechanism acting on the intermediate gateways. We describe a new active queue management scheme, Effective RED (ERED) that aims to reduce packet loss rates in a simple and scalable manner. We made a few change to packet drop function of existing RED scheme. The rest of the original RED remains unchanged. We achieve this by making several refinements and by controlling packet dropping function both with average queue size and instantaneous queue size. Simulations demonstrate that ERED achieves a highest throughput and lowest packet drops than RED, Blue, REM, FRED, LDC and SRED. Since ERED is fully compatible with RED, we can easily upgrade/replace the existing RED implementations by ERED.

An effective network congestion control method for multilayer network

The congestion control problem in a single node network has been solved by the nonlinear feedback control method, which has been proven to be effective and robust for different router’s queue size. However, these control models are based on the single layer network architecture, and the senders and receivers are directly connected by one pair of routers. With the network architecture being more and more complex, it is a serious problem how to cooperate many routers working in the multilayer network simultaneously. In this paper, an effective Active Queue Management (AQM) scheme to guarantee the stability by the nonlinear control of imposing some restrictions on AQM parameter in multilayer network is proposed. The nonlinear control can rely on some heuristics and network traffic controllers that appear to be highly correlated with the multilayer network status. The proposed method is based on the improved classical Random Early Detection (RED) differential equation and a theorem for network congestion control. The theorem proposed in the paper proved that the stability of the fluid model can effectively ensure the convergence of the average rate to its equilibrium point through many routers in multilayer network. Moreover, when the network capacity is larger, the proposed scheme can still approach to the fullest extensibility of utilization and ensure the stability of the fluid model. The paper reveals the reasons of congestion control in multilayer network, provides a theorem for avoiding network congestion, and gives simulations to verify the results.

A fuzzy-logic control algorithm for active Queue Management in IP networks

Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the predominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theoretical analysis and Network Simulator (NS) simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router’s ability in network congestion control in IP network.