A Fuzzy Flow Control Approach for ABR Service in ATM Networks

The explicit rate flow control mechanisms for ABR service are used to sharethe available bandwidth of a bottleneck link fairly and reasonably among many competitive users andto maintain the buffer queue length of a bottleneck switch connected to the link at a desired levelin order to avoid and control congestion in ATM networks. However, designing effective flow controlmechanisms for the service is known to be difficult because of the variety of dynamic parametersinvolved such as available link bandwidth, burst of the traffic, the distances between ABR sourcesand switches. In this paper, we present a fuzzy explicit rate flow control mechanism for ABRservice. The mechanism has a simple structure and is robust in the sense that the mechanism'sstability is not sensitive to the change in the number of active virtual connections (VCs). Manysimulations show that this mechanism can not only effectively avoid network congestion, but alsoensure fair share of the bandwidth for all active VCs regardless of the number of hops theytraverse. Additionally, it has the advantages of fast convergence, low oscillation, and high linkbandwidth utilization.

Intelligent Flow Control Technique of ABR Service in ATM Networks Based on Fuzzy Neural Networks

ＩｎｔｅｌｉｇｅｎｔＦｌｏｗＣｏｎｔｒｏｌＴｅｃｈｎｉｑｕｅｏｆＡＢＲＳｅｒｖｉｃｅｉｎＡＴＭＮｅｔｗｏｒｋｓＢａｓｅｄｏｎＦｕｚｚｙＮｅｕｒａｌＮｅｔｗｏｒｋｓ①ＺｈａｎｇＬｉａｎｇｊｉｅＬｉＹａｎｄａＬｉＱｉｎｇｈｕａＷａｎｇＰｕ（ＤｅｐｔｏｆＡ...

Congestion control scheme in ATM networks based on fast tracing-queue

One of the more challenging and unresolved issues in ATM networks is the congestion control of available bit rate （ABR）. The dynamic controller is designed based on the control theory and the feedback mechanism of explicit rates With the given method of a chosen parameter, it can guarantee the stability of the controller and closed loop system with propagation delay and bandwidth oscillation. It needs less parameters（only one） to be designed. The queue length can converge to the given value in the least steps. The fairness of different connections is considered further. The simulations show better performance and good quality of service（QoS） is achieved.

Performance and robustness analysis of a fuzzy-immune flow controller in ATM networks with time-varying multiple time-delays

For the Asynchronous Transfer Mode （ATM） networks with time-varying multiple time-delays, a more realistic model for the available bit rate （ABR） traffic class with explicit rate feedback is introduced. A fuzzy-immune controller is designed, which can adjust the rates of ABR on-line, overcome the bad effect caused by the saturation nonlinearity and satisfy the weighted fairness. Also, the sufficient condition that guarantees the stability of the closed-loop system with a fuzzy-immune controller is presented in theory for the first time. The algorithm exhibits good performance, and most importantly, has a solid theoretical foundation and can be implemented in practice easily. Simulation results show that the control system is rapid, adaptive, robust, and meanwhile, the quality of service （QoS） is guaranteed.

Binary ABR flow control over ATM networks with uncertainty using discrete-time variable structure controller

A binary available bit rate （ABR） scheme based on discrete-time variable structure control （DVSC） theory is proposed to solve the problem of asynchronous transfer mode （ATM） networks congestion in this paper. A discrete-time system model with uncertainty is introduced to depict the time-varying ATM networks. Based on the system model, an asymptotically stable sliding surface is designed by linear matrix inequality （LMI）. In addition, a novel discrete-time reaching law that can obviously reduce chatter is also put forward. The proposed discrete-time variable structure controller can effectively constrain the oscillation of allowed cell rate （ACR） and the queue length in a router. Moreover, the controller is self-adaptive against the uncertainty in the system. Simulations are done in different scenarios. The results demonstrate that the controller has better stability and robustness than the traditional binary flow controller, so it is good for adequately exerting the simplicity of binary flow control mechanisms.

A New Approach to VC Routing in ATM Networks

A new ant-algorithm-based routing approach is proposed for the VC routing problem with considering the comprehensive effect between the resource utilization and the load balance in ATM networks. In the approach, the backup paths are calculated first, and then an ant algorithm based on the ability of ants to find the shortest path between their nest and the food source during their searching food, is constructed to optimize the VC global route. Simulation results show that the proposed approach can realize VC routing effectively according to the current traffic states in the networks and the user-specified delay requirements.

Congestion control for ATM multiplexers using neural networks：multiple sources／single buffer scenario

A new neural network based method for solving the problem of congestion control arising at the user network interface (UNI) of ATM networks is proposed in this paper. Unlike the previous methods where the coding rate for all traffic sources as controller output signals is tuned in a body, the proposed method adjusts the coding rate for only a part of the traffic sources while the remainder sources send the cells in the previous coding rate in case of occurrence of congestion. The controller output signals include the source coding rate and the percentage of the sources that send cells at the corresponding coding rate. The control methods not only minimize the cell loss rate but also guarantee the quality of information (such as voice sources) fed into the multiplexer buffer. Simulations with 150 ADPCM voice sources fed into the multiplexer buffer showed that the proposed methods have advantage over the previous methods in the aspect of the performance indices such as cell loss rate (CLR) and voice quality.

A DYNAMIC BANDWIDTH CONTROL SCHEME OF VP IN ATM NETWORKS

This paper proposes an efficient adaptive bandwidth allocation scheme of virtual paths. The bandwidth of a virtual path is dynamically adjusted according to the link residual capacity. The scheme can remarkably reduce the load on node processing and simplify the network architecture, while keeping higher transmission efficiency. The excellent performance is proved by detailed theoretical analyses.

AVariablebitrateVideoCodingSchemeBasedonMorphologicalOperationsforATMNetworks

ＡＶａｒｉａｂｌｅｂｉｔｒａｔｅＶｉｄｅｏＣｏｄｉｎｇＳｃｈｅｍｅＢａｓｅｄｏｎＭｏｒｐｈｏｌｏｇｉｃａｌＯｐｅｒａｔｉｏｎｓｆｏｒＡＴＭＮｅｔｗｏｒｋｓＣｈｅｎＨｕｉｆａｎｇＤａｉＷｅｎｑｉＱｉｕＰｅｉｌｉａｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＩｎｆｏ...

Source Timing Recovery of Constant-bit-rate(CBR) Services in ATM Networks

Asynchronous Transfer Mode(ATM)technique is regarded as an efficient approach forthe integration of diverse types of services in Broadband Integrated Services Digital Network(B-ISDN).The Asynchronous-Time-Division(ATD)Statistical Multiplexing and FastPacket Switching in ATM networks bring serious uncertainty to the end-to-end Cell DelayVariation(CDV)of the CBR traffic(e.g.voice,audio,CBR video,etc.)and cause troublesfor the Source Timing Recovery(STR)of CBR services.This paper discusses the originsand features of the CDV,two STR implementation methods proposed by the InternationalTelecommunication Union(ITU),and an optimal STR scheme with a Digital-to-AnalogConverter(DAC)based Phase-Locked Loop(PLL).

VBR WAVELET VIDEO CODING AND ITS RATE CONTROL IN ATM NETWORKS

This paper presents a new video coding system based on wavelet transform and its rate control scheme over ATM networks. First, three dimensional wavelet transform is performed for the original image sequence, and an extension of set partitioning in hierarchical trees algorithm is employed to quantize the wavelet coefficients. Then, the output rate of the coder is controlled at group of frame scale, ensuring that it conforms to the parameters of a leaky bucket controller. Several leaky buckets with different sizes are discussed too. Simulation shows the efficiency of this codec and the effectiveness of the proposed rate control scheme.

THE EFFECT OF VP SWITCHES ON THE PERFORMANCE OF BACKUP-VP ALGORITHM IN ATM SELF-HEALING NETWORKS

In this approach, three typical implementation schemes of self-healing function in VP switches are discussed and three corresponding queue models for backup-VP self-healing algorithm are established. Computer simulations are made to these queue models, and detailed analyses are presented to the effect of both the three implementation schemes of self-healing function and some architecture parameters in VP switches on self-healing performance.

Dynamic Bandwidth Allocation Technique in ATM Networks Based on Fuzzy Neural Networks and Genetic Algorithm

ＤｙｎａｍｉｃＢａｎｄｗｉｄｔｈＡｌｏｃａｔｉｏｎＴｅｃｈｎｉｑｕｅｉｎＡＴＭＮｅｔｗｏｒｋｓＢａｓｅｄｏｎＦｕｚｙＮｅｕｒａｌＮｅｔｗｏｒｋｓａｎｄＧｅｎｅｔｉｃＡｌｇｏｒｉｔｈｍ①ＺｈａｎｇＬｉａｎｇｊｉｅＬｉＹａｎｄａＷａｎｇＰｕ（Ｄｅｐｔｏｆ...

A DYNAMIC TRANSMISSION CAPACITY ALLOCATION SCHEME FOR WIRED/WIRELESS ATM NETWORKS

The previous research on administration of the transmission capacity in the wired/ wireless ATM networks only focuses on wired part or wireless part. There are very few people do the work extending to the links associating with handoff in the whole network. This paper develops the algorithms of transmission capacity administration on the link connecting the base station and base station controller (including the air interface of the base station) and the VPs among the base station controllers in the wired/ wireless ATM networks, which adapt to the traffic state of each service in every cellular cell to allocate (provision) transmission capacity and to reserve handoff guard capacity on these links, respectively. By simulating and analyzing the performance of the algorithm, it is found that it does well for the multimedia communication in which the transmission capacity requirement of each service may be widely different, so that the network bandwidth resource can be used efficiently.

PERFORMANCE ANALYSIS OF LEAKY BUCKET ALGORITHM WITH BURSTY TRAFFIC INPUT IN ATM NETWORKS

A bursty traffic model is introduced in this paper to describe the statistical characteristics of packet video. The performance of leady bucket algorithm with bursty traffic input is analyzed. The influences of various parameters on QOS (Quality of Service) are investigated. The analysis shows that although the loss probability decreases through expanding the buffer capacity, the delay and delay jitter increase, whose effect on QOS will not be negligible.

A CONNECTION ADMISSION CONTROL SCHEME BASED ON GAME THEORETICAL MODEL IN ATM NETWORKS

In this paper, the main schemes of connection admission control (CAC) in ATM networks are briefly discussed especially the principle of dynamic bandwidth allocation. Then the fair share of the bandwidth among different traffic sources is analyzed based on cooperative game model. A CAC scheme is proposed using the genetic algorithm (GA) to optimize the bandwidth-delay-product formed utilization function that ensures the fair share and accuracy of accepting/rejecting the incoming calls. Simulation results show that the proposed scheme ensures fairness of the shared bandwidth to different traffic sources.

A New SDH-Based ATM Network Survivability Escalation Mechanism

This paper investigates survivability escalation strategies in multi layers transport networks such as ATM/SDH/WDM networks, and presents oriented failures and oriented traffic escalation mechanisms. Furthermore, We present a new survivability Escalation strategy for SDH Based ATM transport networks, which addresses difficult problem for resources sharing pool(RSP) among different layers restoration mechanisms. In this paper, we also present integer programming (IP) model for the resources sharing pool (RSP) design problem and the node simulation model for escalation Node. The simulation results show that the proposed ESP is very efficient. The proposed model can be easily extended for other types of multi layer networks, such as WDM based ATM networks or WDM based SDH networks.

Design of ATM Networks Congestion Controller Based on the Virtual Queue

The single bottleneck node of ATM networks is considered. The virtual queue mechanism and the method of proportion-integral-differential(PID) control are adopted in the congestion control. The sufficient condition of the considered system’s stability is given. The method of determining the PID parameters is given further. To quicken the speed of startup and remove the congestion rapidly, the factors of increase and decrease are set according to the length of queue. The result of simulation shows that the system, given an appropriate group of parameters, can acquire good robustness and dynamic performance, and guarantees the quality of service at the same time.

Congestion Control for ATM Networks Based on Diagonal Recurent Neural Networks

ＣｏｎｇｅｓｔｉｏｎＣｏｎｔｒｏｌｆｏｒＡＴＭＮｅｔｗｏｒｋｓＢａｓｅｄｏｎＤｉａｇｏｎａｌＲｅｃｕｒｅｎｔＮｅｕｒａｌＮｅｔｗｏｒｋｓＨｕａｎｇＹｕｎｘｉａｎＹａｎＷｅｉ（ＡｉｒＦｏｒｃｅＩｎｓｔｉｔｕｔｅｏｆＭｅｔｅｏｒｏｌｏｇｙ，Ｎａｎｊｉｎｇ...

ATM网络中面向ABR服务的一种流量控制机制

在ATM网络有效和稳定的运行过程中 ,拥塞控制起着重要的作用 .对此 ,本文提出一种方法来设计基于速率的流量控制机制以便调节ABR服务并有效地控制网络拥塞 .目标是在多个竞争用户间公平分配可用链路带宽、维持瓶颈结点的队列长度在希望值 .该机制基于最小节拍 (DR)控制并具有非常简单的结构 .仿真结果表明 ,该控制机制是公平的并且具有快速收敛。