ATM突发性业务阻塞控制

在ＡＴＭ网里业务阻塞控制是一个十分重要的问题，本文对一种缓冲漏桶业务阻塞控制算法在突发性业务输入情况下的性能进行了计算机模拟分析，模拟结构表明缓冲漏桶算法是一种适合于突发性业务的阻塞控制算法，文章在模拟结果的基础上给出了缓冲漏桶算法中参量选择的算法。     

基于MPLS流量工程的拥塞控制机制

提出了一种闭环的基于MPLS流量工程的拥塞控制协议-TECC,它能在MPLS网络中检测拥塞,根据拥塞状况动态地重新分配资源,以达到消除拥塞,优化利用网络资源的目的。为实现这一机制,首先对IETF提出的受限路由消息分发协议CR-LDP作了改进和扩充,定义了一些新的信令消息,用来通告拥塞,重新协商资源,以及统计网络状态。并通过仿真器OPNET对TECC进行了仿真和验证。     

一种改进的分层多播拥塞控制方案

针对分层多播接收者的可用带宽异构性问题,提出了一种自适应动态分层多播拥塞控制算法(ADLM).ADLM自适应地运用最优层输率分配算法来满足接收者的异构性,ADLM可以根据网络情况变化动态地调整分层的数量以及每一分层的层速率.仿真实验表明,该拥塞控制策略比分层组播控制常用的典型策略(RLC)更有效地利用网络带宽,解决网络带宽的异构性问题,同时ADLM是TCP友好的,较好地改进了分层多播拥塞控制的性能.     

网络拥塞控制中探测元机制的研究

为提高TCP协议在长时延、高差错率网络中的性能，探测元机制做为一种主动自适应机制，在TCP的许多改进实现中被涉及。详细阐述了探测元机制的原理和具体应用，并在NS仿真中实现了该机制。理论分析和仿真实验显示，在TCP中引入探测元机制，能有效提高长时延、高差错率网络的吞吐量。     

基于显式速率的TCP友好的UDP拥塞控制策略

本文提出了一种基于显式速率的UDP拥塞控制策略：通过源端和网络中的路由器相互配合，使得实时UDP应用能够根据网络的反馈以瓶颈链路的公平带宽为速率发送数据。此种控制策略对TCP应用是友好的，并且提高了网络的吞吐量和利用率。仿真结果表明：基于显式速率的UDP拥塞控制策略与采用TFRC(TCP—Friendly Rate Control)的UDP拥塞控制策略相比，在吞吐量、TCP友好性等方面性能有较大提高。     

Evolutionary Minority Game Model for Congestion Control Scheme

Telecommunication technology advances in the past decade have brought networking to another level in terms of reliability and link speeds. However, existing transmission control protocols do not provide satisfactory performance due to their inefficient congestion control mechanisms. In this paper, we propose a new congestion control scheme to provide Quality of Service provisioning while ensuring bandwidth efficiency. Based on the evolutionary minority game (EMG) model, the proposed algorithm adaptively controls the packet transmission to converge a desirable network equilibrium. For the efficient network management, the proposed EMG approach is dynamic and flexible that can adaptively respond to current network conditions. A simulation shows that our proposed scheme can approximate an optimized solution while ensuring a well-balanced network performance under widely different network environments.     

WCDMA拥塞控制方法分析

网络拥塞和过载直接影响到3G网络的性能和服务质量.本文阐述了WCDMA网络中的拥塞控制原理,并针对几种重要的拥塞控制方法分别进行了分析.最后,针对维护优化中可能出现的问题,提出了建议和解决思路.     

A Timeout-Based Congestion Control Scheme for Window Flow-Controlled Networks

During overload, most networks drop packets due to buffer unavailability. The resulting timeouts at the source provide an implicit mechanism to convey congestion signals from the network to the source. On a timeout, a source should not only retransmit the lost packet, but it should also reduce its load on the network. Basedon this realization, we have developed a simple congestion control scheme using the acknowledgment timeouts as indications of packet loss and congestion. This scheme does not require any new message formats, therefore, it can be used in any network with window flow control, e.g., ARPAnet or ISO.     

ATM网络中ABR业务的监控方案

基于离散事件动态系统理论,提出了一种崭新的用于控制ＡＴＭ网络中ＡＢＲ业务流量的监控方案,这种方案具有简单易于实现的特点,仿真结果与理论预测值的一致证明了该方案的正确性。     

基于信任及能量评估的AODV安全路由

在Ad Hoc网络中,动态拓扑及自由移动的特点使恶意节点发起各种攻击造成网络资源不可用。为此提出移动频率(MF,Mobile Frequency)评估节点移动情况。同时,在AODV的基础上,提出一个基于节点信任度和能量的路由方案,该方案中节点信任度受移动频率影响,下一跳节点的选择由信任度和能量共同决定,并通过区分可信与不可信节点,孤立恶意节点来保证路径上的节点都有足够能量并且安全可信。     

基于LFSN业务流量模型的网络拥塞控制算法

网络业务流的多分形本质可以用LFSN（线性分形稳定噪声）准确建模，文中提出了基于LFSN模型预测的网络拥塞控制算法并进行了仿真分析，结果表明该算法提高了网络链路吞吐量，减小了丢包率。     

Towards Robust Multi-Layer Traffic Engineering: Optimization of Congestion Control and Routing

In the Internet today, traffic engineering is performed assuming that the offered traffic is inelastic. In reality, end hosts adapt their sending rates to network congestion, and network operators adapt the routing to the measured traffic. This raises the question of whether the joint system of congestion control (transport layer) and routing (network layer) is stable and optimal. Using the established optimization models for TCP and traffic engineering as a basis, we find the joint system can be stabilized and often maximizes aggregate user utility. We prove that both stability and optimality of the joint system can be guaranteed for sufficiently elastic traffic simply by tuning the cost function used for traffic engineering. Then, we present a new algorithm that adapts on a smaller timescale to changes in traffic distribution and is more robust to large traffic bursts. Uniting the network and transport layers in a multi-layer approach, this algorithm, distributed adaptive traffic engineering (DATE), jointly optimizes the goals of end users and network operators and reacts quickly to avoid bottlenecks. Simulations demonstrate that DATE converges quickly     

TCP拥塞控制机制及性能分析

随着因特网的迅猛发展,因特网中的业务量呈逐年上升趋势,研究了TCP拥塞控制机制及其提供的拥塞控制性能,特别是对TCP连接过程中的数据业务流量与丢失率和其他参数的关系进行了深入的研究。分析表明TCP拥塞控制机制可通过控制注入网络的业务流量,在一定程度下缓解网络拥塞程度,但不能实现数据的有效率的传输。     

Stability Analysis of Explicit Congestion Control Protocols

In the context of explicit congestion control protocols like XCP and RCP where the equilibrium queue lengths are zero, we show that the stability region derived from traditional Nyquist analysis is not an accurate representation of the actual stability region, and that the use of switched linear system models with time delay and new Lyapunov tools can provide sound sufficient stability conditions.     

一种基于反馈时延的ABR业务拥塞控制方案

针对ATM网络提出了一种基于时延的ABR业务拥塞控制方案，并给出了方案性能分析和仿真结果。     

ATM网络拥塞控制的缓存性能分析

文章针对一种简单的拥塞控制模型,分析了拥塞控制的缓存性能,得到了精确的缓存空间Ｂ和阈值θ。指出拥塞控制运行机制缓存过大的原因,给出了合理的拥塞控制运行机制的缓存性能的分析。仿真结果验证了分析的正确性。     

无线网络中TCP拥塞控制算法的性能分析

根据无线网络中存在随机数据包丢失的特定情况,对TCP拥塞控制算法在无线网络中的性能进行了分析。理论分析和仿真结果表明,随着无线链路中随机数据包丢失概率的增加,TCP拥塞控制算法将导致无线网络性能的严重下降。     

B－ISDN中的拥塞控制技术

Ｂ－ＩＳＤＮ是现代电信网的发展方向，拥塞控制技术则是其中的一个重要问题。由于Ｂ－ＩＳＤＮ采用新的信息传递方式──ＡＴＭ，使传统的拥塞控制方法不再适用。本文依据ＩＴＵ－Ｔ有关建议的最新内容对Ｂ－ＩＳＤＮ拥塞控制的基本思想、工作机制以及其中的主要功能作了较为详细的分析讨论，并提出了一些Ｂ－ＩＳＤＮ拥塞控制技术中尚需进一步研究的问题。     

REFWA: An Efficient and Fair Congestion Control Scheme for LEO Satellite Networks

This paper examines some issues that affect the efficiency and fairness of the Transmission Control Protocol (TCP), the backbone of Internet protocol communication, in multi-hops satellite network systems. It proposes a scheme that allows satellite systems to automatically adapt to any change in the number of active TCP flows due to handover occurrence, the free buffer size, and the bandwidth–delay product of the network. The proposed scheme has two major design goals: increasing the system efficiency, and improving its fairness. The system efficiency is controlled by matching the aggregate traffic rate to the sum of the link capacity and total buffer size. On the other hand, the system min-max fairness is achieved by allocating bandwidth among individual flows in proportion with their RTTs. The proposed scheme is dubbed Recursive, Explicit, and Fair Window Adjustment (REFWA). Simulation results elucidate that the REFWA scheme substantially improves the system fairness, reduces the number of packet drops, and makes better utilization of the bottleneck link. The results demonstrate also that the proposed scheme works properly in more complicated environments where connections traverse multiple bottlenecks and the available bandwidth may change over data transmission time.     

Efficient Route Selection Scheme in MANET Using Enhanced AODV Protocol

Mobile Ad Hoc network comprises of mobile nodes communicating over wireless medium. Due to ease of communication and flexibility, MANET has become an active area of research in wireless communication. However, issues such as limited battery capacity, dynamic topology and node mobility cause frequent link breakage due to which reroute discovery process is required to be initiated resulting in increase in latency and routing overheads. Many research works have been carried out for improvement of an existing routing scheme, however they do not scale-up well to provide stable and energy efficient route. This paper introduces a novel routing algorithm ENH-AODV (Enhanced AODV) that focuses on selection of an efficient route on the basis of quality of both links and nodes impending during route discovery process. In addition, each node maintains a list, consisting of details of nearby nodes with good energy level through hello mechanism. Simulation is carried out over network simulator and results prove that the proposed scheme is more effective and advantageous than AODV in terms of normalized routing load, end to end delay, packet delivery ratio and throughput.