具有漏桶控制的ATM复接器性能分析

提出了用间断贝努利过程可近似描述突发源经漏桶后的输出过程。分析了综合业务环境下，具有漏桶控制的ＡＴＭ复接器的性能。计算机模拟验证了分析的正确性。     

突发性业务环境下周期性信元流通过ATM复接器的时延抖动

在输入ＡＴＭ网络的业务源中，周期性元流是很重要的一种，本文精确地分析了一个有限缓存在的ＡＴＭ复接器，其输入业务源由一路周期性信元流，多路随机性贝努利（Ｂｅｒｎｏｕｌｌｉ）信元流和突发性两状马尔科夫调制贝努利（ＭＭＢＰ）信元泫构成，得出了该路周期性信元流的排队时延分布，时延抖动的自相关函数和功率谱，揭示了突发性业务环境下周期性信元流通过ＡＴＭ复接器的时延抖动行为，计算机模拟验证了分析结果的正确性。     

多路ON—OFF信源通过ATM复接器时信元丢失的分析和估计

本文采用类似半导体中“空穴”的思想对离散流体地作了推广，使其适合于两状态ＭＭＤＰ的信源通过ＡＴＭ复接器时的排队分析，然后进一步将它应用于多路ＮＯ－ＯＦＦ信源复接时信元丢失率的分析，经过适当近似以后，得到信元丢失率的闭环表达式。仿真和数值计算表明，该方法准确且适于实时运算，将对ＡＴＭ中呼叫接入控制和资源分配产生积极的影响。     

用FPGA实现智能复接器的小型化

介绍现场可编程门阵列（ＦＰＧＡ）的性能特点及其在工程应用中的设计过程，介绍△Ｍ制式数字程控交换机复接器的工作原理，最后给出一个在实陈工程中用ＦＰＧＡ实现智能复接器小型化的设计实例和设计结果。     

一种调度ATM网中实时业务的新方法

实时业务是ＡＴＭ网络中一类重要的业务,相对于非实时业务这类业务有更严格的服务质量要求,好的复接器调度策略是实时业务服务质量的一个重要保证,本文提出一种调度实时业务的新方法,给出并证明了该方法可调度的充分必要条件,该方法在大大降低复接器工作量的同时,保证了较高的频带资源利用率,将对实时业务的传输控制产生积极的影响。     

CMOS工艺复接器模块中选择器的设计

在光纤传输系统中,为了提高信道的利用率,需要用复接器将多路低速信号合成一路高速信号。选择器就是高速复接器模块中的关键部分,选择器的逻辑功能和性能直接影响复接器的工作。由于源极耦合场效应管逻辑(SCFL)电路工作速率高,因此选择器的设计就采用了SCFL电路结构。设计采用全定制的设计方法,在参数调整过程中,采用一种观察分组的新方法,并用SmartSpice进行了仿真,其结果达到了预期的目标。     

ATM网络中自相似业务下复接器性能的研究

近期对大量实际网络的测量表明,现代网络的业务流特性和部分信源的特性,更适于采用具有长期相关性的自相似或分形模型来描述。已有研究表明长期相关业务的排队特性与基于短期相关模型的有很大不同。但对于自相似业务下ＡＴＭ网络中复接器性能的研究尚未深入进行。本文在提出一种准自似（ＱＳＳＰ）的长期相关业务流模型的基础上,求得了Ｎ路同参数ＱＳＳＰ输入时复接器的信元丢失率和复接增益,并对非同参数输入的情况提出了一种快     

用于两个独立网的用户环路数字复接器

文章介绍用于两个独立网间的用户环路数字复接器，分析了用户环路数字复接器怎样在两个独立的拥有各自时钟的网间进行话音的传输。     

节点交换机与复接器间的控制信令

节点交换机和复接器是野战网中的两项关键设备。本文从分析EB交换机软件出发,总结整理出这两项设备间的管理信息,包括设备识别过程、连接状态提取过程、复接器编程数据修改、交换机对复接器编程、状志查询过程和测试过程,并详细介绍了完成上述过程的信令收发技巧和处理方法。本文的信令过程对于编制两设备间的控制信息标准提供借鉴,信令处理方法和技巧对日后的设备研制和改进也有参考价值。     

用FPGA实现具有多种数据接口的复分接器

为了提高数据传输设备的传输速率，扩大系统的传输容量，本文设计了一种将两路异步数据、两路话音数据和一路同步数据复接为一路复合数据信号，并在接收端再分离成各个分路信号的复分接器，该复分接器可以满足多种功能需求，有很好的应用前景。     

A novel approach to estimating the cell loss probability in an ATMmultiplexer loaded with homogeneous on-off sources

Estimating the cell loss probability in an ATM multiplexer is one of the most important problems concerning congestion control and bandwidth management in an ATM-based BISDN. We propose a new approach to estimating the cell loss probability in an ATM multiplexer. We use the Markov modulated deterministic process (MMDP) to approximate the actual arrival process and then model the ATM multiplexer as an MMDP/D/1/K queueing system. Using queueing analysis, we derive a formula for the cell loss probability expressed in terms of the limiting probabilities of a Markov chain. We propose two approximation methods based on the results of the analysis. The actual arrival process is approximated by an (M+1)-state MMDP in the first method and by a two-state MMDP in the second. The major advantages of both methods are simplicity, computational efficiency, and numerical stability. The most attractive feature of the second method is that the cell loss probability can be expressed in closed form. Numerical and simulation results show that the first method is sufficiently accurate for all cases in which burst-level congestion is the main contributing factor to cell loss, while the closed-form formula is sufficiently accurate for applications where the average burst length is large (such as large file transfers, image retrievals, etc.)     

突发性业务环境下周期性信元流通过ATM复接器的时延抖动

在输入ATM网络的业务源中,周期性信元流是很重要的一种.本文精确地分析了一个有限缓存的ATM复接器,其输入业务源由一路周期性信元流、多路随机性贝努利(Bernoulli)信元流和突发性两状态马尔科夫调制贝努利(MMBP)信元流构成.得出了该路周期性信元流的排队时延分布、时延抖动的自相关函数和功率谱.揭示了突发性业务环境下周期性信元流通过ATM复接器的时延抖动行为.计算机模拟验证了分析结果的正确性.     

DELAY JITTER OF A PERIODIC CELL STREAM THROUGH AN ATM MULTIPLEXER IN A BURSTY TRAFFIC ENVIRONMENT

The periodic cell stream is a very important member among the input traffic sources in ATM networks. In this paper, a finite-buffered ATM multiplexer with traffic sources composed of a periodic cell stream, multiple i.i.d Bernoulli cell streams and bursty two-state Markov Modulated Bernoulli Process (MMBP) cell streams is exactly analyzed. The probability mass function of queuing delay, the autocorrelation and power spectrum of delay jitter for this periodic cell stream are derived. The analysis is used to expose the behavior of delay jitter for a periodic cell stream through an ATM multiplexer in a bursty traffic environment. The simulation results indicate that the analytical results are accurate.     

AAL2分组话音复接器的研究与实现

该文研究在ATM虚通路带宽利用率一定的条件下,AAL2分组话音复接器性能随ATM虚通路输出速率的增加而变化的情况。得出结论:当ATM虚通路带宽利用率一定时,ATM虚通路输出速率越高,AAL2分组话音复接器的分组丢弃概率和平均分组排队时延越小。并提出了一种AAL2分组话音复接器的实现方案。该方案可以随着ATM虚通路输出速率的增加,方便地复接多个E1话音电路上的话音数据。     

Performance Analysis of an ATM Multiplexer with Multiple QoS VBR Traffic

In this paper, we propose a new queuing model, MMDP/MMDP/1/K, for an asynchronous transfer mode (ATM) multiplexer with multiple quality of service (QoS) variable bit rate (VBR) traffic in broad band-integrated services digital network (B-ISDN). We use the Markov Modulated Deterministic Process (MMDP) to approximate the actual arrival process and another MMDP for service process. Using queuing analysis, we derive a formula for the cell loss probability of the ATM multiplexer in terms of the limiting probabilities of a Markov chain. The cell loss probability can be used for connection admission control in ATM multiplexer and the calculation of equivalent bandwidth for arrival traffic. The major advantages of this approach are simplicity in analysis, accuracy of analysis by comparison of simulation, and numerical stability.     

具有业务量平滑功能的ATM交换机的性能分析

ATM网络支持大量的突发业务源。突发业务量可用间断Bernoulli过程描述。本文采用一种循环算法,分析了ATM交换机在既有连续比特流业务量又行突发业务量环境下的信元丢失率和平均延迟。数值分析结果和计算机仿真结果一致表明,具有业务量平滑功能的ATM交换机的性能有较大改进。     

周期性业务流通过ATM复用器的时延抖动分析

ＡＴＭ通信网中需要传送多种业务，其中有一类是具有连续比特流的业务，这种业务的发送信元到达时间是周期性的，本文分析了一种周期性信元流通过ＡＴＭ复用器的排队模型，得出信元流排队时延的概率分布，时延抖动的自相关函数的功率谱。     

具有质量控制功能的ATM交换节点的性能分析

本文提出一种用于ＡＴＭ网的质量控制方法－动态到达控制（ＤＡＣ），分析了采用ＤＡＣ的ＡＴＭ交换节点中，各类业务信元的丢失概率和平均时延，分析结果表明，ＤＡＣ是一种有效的质量控制方式，它能够提供多种服务等级以满足不同的需要，减小所有信元的平均时延，提高系统的有效吞吐量。     

具有大容量缓存器的ATM网络交换节点的接入允许控制

本文讨论了ＡＴＭ网络交换节点的缓存器容量较大时,如何实现实时接入允许控制的问题。我们从大量的计算机模拟的结果中发现,对于符合负指数分布的马尔可夫ＯＮ／ＯＦＦ单一类型或多类型信源,在信元及系统的其它参数保持不变的条件下,信元丢失概率和丢失率,只取决于缓存器容量与信元平均突发长度的比值。本文从“生灭过程”出发加以了证明。     

An error-controlled approximate analysis of a stochastic fluid flowmodel applied to an ATM multiplexer with heterogeneous on-off sources

The stochastic fluid flow approach is applied to the analysis of the cell loss performance of an ATM multiplexer. The input traffic stream offered to the multiplexer is the superposition of heterogeneous on-off sources with independent and exponentially distributed on and off times. The focus is on the numerical investigation of the steady-state behavior of models involving very large state spaces. To this end, an efficient algorithm for the evaluation of tight upper and lower bounds of the cell loss probability is developed. The algorithm allows a significant reduction of the computational burden, while yielding a guaranteed overestimate of the error implied by the proposed approximation of the cell loss probability. Numerical results are presented both to assess the tightness of the proposed bounds and to gain insight into the behavior of heterogeneous traffic mixes. The main conclusion, from the multiplexer performance evaluation point of view, is that it is not convenient to mix very different traffic streams in a completely shared FIFO buffer, without some kind of control