QuSAT在SCADA系统中的应用分析

本文主要介绍了使用码分多址（ＣＤＭＡ）的ＱｕＳＡＴ系统原理和特点，讨论了ＱｕＳＡＴ网络在ＳＣＡＤＡ系统中的应用结构，着重分析了ＶＳＡＴ和ＱｕＳＡＴ网络的时延特性，提出了基于ＱｕＳＡＴ网络的ＳＣＡＤＡ系统模型。     

基于GCRA（T,δ）的CDV成形算法及其实现

文章提出基于通用信元速率算法ＧＣＲＡ（Ｔ，δ）的ＣＤＶ成形算法，该算法能有效地成形ＣＤＶ使之符合ＧＣＲＡ（Ｔ，δ）算法对ＣＤＶ容限的要求，并对ＣＤＶ成形器的实现和操作进行了讨论。     

PECVDSiN及其在GaAsMESFET中的应用第Ⅱ部分：PECVDSiN的性质及其对GaAs器件性能的影响

ＰＥＣＶＤＳｉＮ及其在ＧａＡｓＭＥＳＦＥＴ中的应用第Ⅱ部分：ＰＥＣＶＤＳｉＮ的性质及其对ＧａＡｓ器件性能的影响罗海云（电子部第１３研究所，石家庄，０５００５１）ＰＥＣＶＤＳｉＮａｎｄＩｔｓＡｐｐｌｉｃａｔｉｏｎｉｎＧａＡｓＭＥＳＦＥＴＰａｒｔⅡ：Ｐｒ...     

话音ATM交换——一种现实的网络过渡方案

首先介绍了几种基于ＡＴＭ的话音交换方案，重点提出一种６４ｋｂｓ的话音ＡＴＭ交换（ＶＯＡ）的实现模型．该系统包含了传统ＳＴＭ交换与ＡＴＭ交换间的相互转换，并能有效地解决诸如信元打包时延、信元时延抖动，以及系统带宽利用率等关键环节．最后还介绍了有关话音ＡＴＭ交换（ＶＯＡ）技术的其它热点     

A Novel Voice Coder At 4800BPS(HSEV)

ＡＮｏｖｅｌＶｏｉｃｅＣｏｄｅｒＡｔ４８００ＢＰＳ（ＨＳＥＶ）ＷａｎｇＸｉａｏｆｅｎｇＡＮＤＺｈａｏＥｒｙｕａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＴｅｌｅｃｏｍｒｎｕｎｉｃａｔｉｏｎＥｎｇｉｎｅｅｒｉｎｇ，ＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙｏｆＰｏｓｔｓ＆Ｔ...     

光纤AM—CATV外调制传输中SBS的激光抖动抑制及其对色散非线性与MPI噪声的

对光纤ＡＭ－ＣＡＴＶ外调制传输系统中激光抖动法抑制ＳＢＳ的原理,以及激光抖动法抑制ＳＢＳ时光纤ＡＭ－ＣＡＴＶ中的百线性失真与噪声进行了详细分析了计算,发现激光抖动法对系统的多径干涉（ＭＰＩ）噪声有一定的抑制作用,而且只要抖动信号的频率大于二倍的ＣＡＴＶ频带的最大频率,色散引起的非线性失真还可以忽略不计。     

VSAT系统及其在ISDN中的应用(上)

ＶＳＡＴ系统及其在ＩＳＤＮ中的应用（上）＠邢亚斌ＶＳＡＴ系统及其在ＩＳＤＮ中的应用（上）●邢亚斌ＶＳＡＴ是ｖｅｒｙｓｍａｌａｐｅｒｔｕｒｅｄａｔａｔｅｒｍｉｎａｌ的缩写，中文译为甚小口径数据终端，也称为甚小口径天线。ＶＳＡＴ系统主要用来进行２Ｍｂ／ｓ以下的...     

美国FCC关于高级电视（ATV）的举措

美国ＦＣＣ关于高级电视（ＡＴＶ）的举措１９９５年１１月美国联邦通信委员会（ＦＣＣ）的高级电视顾问委员会（ＡＣＡＴＳ）开会并通过了有关高清晰度电视（ＨＤＴＶ）的最后报告和建议。下一步将是正式的政府行动，即发布规则制定通告（ＮｏｔｉｃｅｏｆＰｒｏｐｏｓｅ...     

一种杜比AC-3编解码模块

杜比ＡＣ－３是一种高效率、高质量、多功能的感知型数字音频编码技术。在１９９２年它就为影院提供多声道的数字音频,在１９９４年应用于二声道的ＤＢＳ（ＤｉｒｅｃｔＢｒｏａｄｃａｓｔＳａｔｅｌｌｉｔｅ）。在消费电子业中它已被广泛用于为盒式或碟式家用视音频设备提供多路数字环绕声音频信号。除用于激光视盘机外,它还被用于ＨＤＴＶ的数字环绕声系统,目前的ＤＶＤ（ＤｉｇｉｔａｌＶｉｄｅｏＤｉｓｃ）格式中也用了ＡＣ－３音频编码系统,其他如ＤＶＣ（ＤｉｇｉｔａｌＶｉｄｅｏＣａｓｓｅｔｔｅ）和ＤＡＢ（ＤｉｇｉｔａｌＡｕ…     

用神经计算机的说话人确认系统及其应用

在国产ＣＡＳＳＡＮＤＲＡ－Ｉ小型神经计算机基础上实现了一种说话人确认（Ｓｐｅａｋｅｒ Ｖｅｒｉｆｉｃａｔｉｏｎ）系统,其性能优于Ｖｅｒｉｔｒｏｎ１０００系统,与美国ＡＴ＆Ｔ研制的Ｖｏｉｃｅ Ｐａｓｓｗｏｒｄ Ｖｅｒｉｆｉｅｒ Ｓｙｓｔｅｍ相当,文中介绍了其结构和测验结果,并讨论了在国民经济中的可能途径。     

Virtual spacing for flexible traffic control

Weighted fair queuing emerges as an elegant and effective solution to the problem of integrating real time services with strict delay constraints and high-speed data services for which significant delays cannot always be avoided. Virtual spacing is a weighted fair queuing scheduling algorithm intended to be applied in the context of the ATM based BISDN. After discussing how virtual spacing allows flexible traffic control for a variety of service types, we discuss the issue of its implementation in switching nodes. The aim of the paper is to highlight the advantages of weighted fair queuing in enabling a truly integrated services network and to propose a technologically feasible implementation.     

The UniMIN switch architecture for large-scale ATM switches

A general expansion architecture is proposed that can be used in building large-scale switches using any type of asynchronous transfer mode (ATM) switch. The proposed universal multistage interconnection network (UniMIN) switch is composed of a buffered distribution network (DN) and a column of output switch modules (OSMs), which can be any type of ATM switch. ATM cells are routed to their destination using a two-level routing strategy. The DN provides each incoming cell with a self-routing path to the destined OSM, which is the switch module containing the destination output port. Further routing to the destined output port is performed by the destination OSM. Use of the channel grouping technique yields excellent delay/throughput performance in the DN, and the virtual FIFO concept is used for implementing the output buffers of the distribution module without internal speedup. We also propose a “fair virtual FIFO” to provide fairness between input links while preserving cell sequence. The distribution network is composed of one kind of distribution module which has the same size as the OSM, regardless of the overall switch size N. This gives good modular scalability in the UniMIN switch. Performance analysis for uniform traffic and hot-spot traffic shows that a negligible delay and cell loss ratio in the DN can be achieved with a small buffer size, and that DN yields robust performance even with hot-spot traffic. In addition, a fairness property of the proposed fair virtual FIFO is shown by a simulation study     

A New Starting Potential Fair Queuing Algorithm with O(1) Virtual Time Computation Complexity

In this paper, we propose an efficient and simple fair queuing algorithm, called new starting potential fair queuing (NSPFQ), which has O(1) complexity for virtual time computation and also has good delay and fairness properties. NSPFQ introduces a simpler virtual time recalibration method as it follows a rate‐proportional property. The NSPFQ algorithm recalibrates the system virtual time to the minimum virtual start time among all possible virtual start times for head‐of‐line packets in backlogged sessions. Through analysis and simulation, we show that the proposed algorithm has good delay and fairness properties. We also propose a hardware implementation framework for the scheduling algorithm.     

APON的MAC协议设计

本文结合以ＡＴＭ为基础的无源光网络（ＡＰＯＮ）的Ｇ．９８３建议,提出了一种低信元时延变化（ＣＤＮ）、低信元时延（ＣＤ）、无碰撞、公平,高效的媒质接入控制（ＭＡＣ）协议,并对该协议的性能进行了分析。     

Spacing cells protects and enhances utilization of ATM networklinks

It is shown that peak cell rate policing can be combined with fast reservation protocols for achieving statistical multiplexing in asynchronous transfer mode (ATM) networks. A cell spacer-controller architecture which smooths out cell clusters according to the original period both at the user network interface (UNI) and at network node interface (NNI) is proposed. A performance evaluation of the spacer-controller is presented. The evaluation involves modeling the spacer-controller, dimensioning a virtual scheduling algorithm, and the impact on cell delay variation (CDV). It is shown that large CDVs may induce severe degradation in the accuracy of usage parameter control/network parameter control mechanisms     

具有突发业务量成形的ATM复接器的性能分析

分析了综合业务环境下，具有突业务量成形的ＡＴＭ复接器的性能，提出了用间断贝努利过程可近似描述突发源经成形器后的输出过程。用改进的迭代算法，求出了ＡＴＭ复接器的信元丢失率和平均延迟。     

An efficient ATM network switch scheduling

The problem of allocating network resources to application sessions backlogged at an individual switch has a great impact on the end-to-end delay and throughput guarantees offered by the network. There exists a class of algorithms based on weighted fair queueing (WFQ) for scheduling packets which are work-conserving and they guarantee fairness to the backlogged sessions. These algorithms also apply to ATM networks with a packet equal to a single cell or an ATM block (of fixed size). Bursts are groups of varying numbers of cells. We generalize WFQ to schedule bursts. Our motivation is to derive an adaptive algorithm which generalizes the (fixed size) packet level to a varying size packet level. The new algorithm enhances the performance of the switch service for many important applications. The proposed scheme maintains the work-conserving property, and also provides throughput and fairness guarantees. The worst-case delay bound is also given. We use simulation to study the performance characteristics of our algorithm. Our results demonstrate the efficiency of the new algorithm.     

An efficient contention resolution algorithm for input queuing atm cross-connect switches

This paper describes an efficient contention resolution algorithm and its distributed implementation for large capacity input queuing cross-connect switches, which will establish virtual paths in future broadband ATM networks. The algorithm dynamically allocates sending time to cells held in input queues when no contention is indicated in the designated output ports. An expression for the mean delay and the cell loss probability for random traffic are derived through an approximate analysis. Input cells are served on a first-come, first-served basis as conventional contention resolution algorithms whose throughput saturates at 58 per cent because of head of line blocking in input queues. The proposed algorithm achieves a maximum throughput of 76 per cent.     

A Modified Dynamic Weighted Round Robin Cell Scheduling Algorithm

In this paper, we propose the modified dynamic weighted round robin (MDWRR) cell scheduling algorithm, which guarantees the delay property of real‐time traffic and also efficiently transmits non‐real‐time traffic. The proposed scheduling algorithm is a variation of the dynamic weighted round robin (DWRR) algorithm and guarantees the delay property of real‐time traffic by adding a cell transmission procedure based on delay priority. It also uses a threshold to prevent the cell loss of non‐real‐time traffic that is due to the cell transmission procedure based on delay priority. Though the MDWRR scheduling algorithm may be more complex than the conventional DWRR scheme, considering delay priority minimizes cell delay and decreases the required size of the temporary buffer. The results of our performance study show that the proposed scheduling algorithm has better performance than the conventional DWRR scheme because of the delay guarantee of real‐time traffic.     

Bandwidth-dependent scheduling algorithm to limit cell delayvariation for CBR traffic in ATM networks

A multiplexing control scheme is proposed for limiting the cell delay variation (CDV) caused by multiplexing of constant bit rate (CBR) traffic in asynchronous transfer mode (ATM) networks. The control scheme is based on a bandwidth-dependent scheduling algorithm. The limitation of the CDV is proved