基于DSL的语音传输

VoDSL是利用数字用户线（DSL）传送多达24条分组语音链路的技术。本文介绍了VoDSL的系统模型,重点讨论了VoDSL系统的实现及技术,最后对其应用和发展趋向进行了预测。     

ATM语音技术

在ＡＴＭ网络上实现语音业务是ＡＴＭ网络发展的关键。文章阐述了ＡＴＭ网络语音业务的现状，实现语音业务所面临的问题和相应的解决方案。     

ATM上行口与以太网上行口的ADSL技术比较

ADSL局端设备为DSLAM,目前一般采用ATM STM-1接口或100M/1000M以太网接口连接到ATM或IP城域网上。对采用ATM上行口和采用以太网上行口的DSLAM进行比较和分析,希望能对选择和使用ADSL设备有所帮助。     

ADSL接入IP网络的研究

随着基于ATM的ADSL宽带接入应用的普及,如何将ADSL顺利地接入以IP为主导的城域网成为一个值得研究的问题。分析了IP over ATM和VLAN等ADSL接入IP网络的相关理论,给出了可行的系统解决方案。     

ADSL网络从ATM向IP的演进

本文简要介绍了ADSL发展情况，承载网从ATM向IP演进，ATM DSLAM向IP DSLAM溶进以及宽带业务发展的一些问题。     

基于ATM宽带业务的ADSL接入研究

ＡＴＭ作为宽带网络的关键技术,取得了很大进展。ＡＤＳＬ则是目前很有潜力的网络接入了在ＡＤＳＬ上传输ＡＴＭ信元的原理和系统模型,在此基础上对各分层模块功能及相应协议进行了研究,并给出了在ＡＤＳＬ上传输ＡＴＭ时几种可能信道分配。     

ATM的现状及发展

本文对ＡＴＭ的主要技术问题和ＡＴＭ技术的应用及目前国内外的现状进行了简要地介绍，并对ＡＴＭ技术在Ｂ－ＩＳＤＮ发展过程中的作用和应用趋势作了展望，从而从技术上指出了ＡＴＭ的研究和发展方向。     

ATM基本交换单元的研究与实现

文章提出并实现了一种共享缓存式ＡＴＭ基本交换单元的设计方案,该交换单元有６条输入输出线路,它由１０片大容量ＦＰＧＡ组成。通过简单的电路修改,用两片超大容量ＦＰＧＡ可以实现９×９或１８×１８共享缓存的ＡＴＭ基本交换单元。     

ATM over ADSL接入网技术研究

详尽阐述了ATMoverADSL接入网的组网方式和网络模块功能,分析了各种不同的协议模型,并得出结论,ATMoverADSI接入网将获得广泛的应用.     

在SDH传输网络上承载ATM数据网络时应注意的问题

简述了SDH网络和ATM网络的特点，重点阐述了在SDH传输网络上建立ATM数据网络时须注意的几个问题。     

基于ATM AAL-2的话音业务

电信网正朝着网络融合和业务综合的方向发展,要实现宽带网与现有窄带电信网络的有效融合,就要求宽带网能够很好地支持现有窄带网络或PSTN中的话音业务,实现话音的包传输与交换。ATM论坛最新通过的基于AAL-2承载话音业务的标准,为实现ATM宽带网与窄带网的融合提供了一个新的途径。本文根据ATM论坛基于AAL-2的话音中继标准,介绍AAL-2话音业务的原理,并给出基于AAL-2话音业务的网络融合方案。     

小型IP-DSLAM技术

从分析小型分散用户的宽带接入技术入手,对ADSL的定义,ADSL主要涉及的技术及需要解决的瓶颈问题进行讨论。结合电信运营商对分散用户宽带业务这一细分市场的需求,提出了一整套理想的适应当代接入网发展的宽带接入技术IP-DSLAM加ADSL的设计方案。     

用AAL5实现话音ATM交换

话音ＡＴＭ交换就是利用ＡＴＭ传输方式,将传统话间通过分组打包实现在ＡＴＭ网络平台上的传输。在分析现有利用ＡＡＬ１传输话间的各项技术后,提出了利用ＡＡＬ５实现话间ＡＴＭ交换的方法。     

无线ATM接入技术在军事通信中的应用

无线ATM技术由于吞吐量大、支持综合业务等一系列优点,在军事通信领域得到了广泛的应用,目前的发展方向是把ATM应用于军用移动通信,在战场上实现运动中的语音、数据、多媒体等业务的实时传输.本论文利用现有成熟的无线ATM接入技术和蜂窝移动网技术,结合现代高技术信息作战对军事通信的要求,研究宽带无线接入在军事通信网中的应用.     

单路话音在ATMAAL5上的传输

1前言ATM到桌面，多媒体到桌面，是信息社会发展的趋势。而对于一台多媒体工作站，不可避‘免的要遇到话音在ATM网上传输的问题。话音速率不高，所占的带宽不宽，但传输质量相对数据来说更加严格，主要表现在传输时延不能太大，数据丢失率和差错率要小等。而单路语音信号对信元的丢失和处理时延都很敏感，因此对单路话音的传输，需要采取一些相应的措施［1」。ATM网络是一个集话音、图像和数据为一体的综合性网络。为了满足各种类型的用户服务要求，ATM论坛和国际电信联盟制定了五种ATM的适配层（AALI～AALS）标准［‘－‘］。虽…     

Evolutionary architecture for an all-services ATM access network

This paper presents a flexible concept for a broadband subscriber access network which minimizes investment costs by predominantly using the existing network infrastructure. The target network may consist of either a coaxial tree-and-branch structure or symmetrical copper pairs to the subscriber, and is connected to the central head station with the aid of optical feeder lines which can be implemented or enhanced by a passive optical network (PON). In the event of an increase in bit rate requirements, the coaxial network can be expanded by dividing it into smaller, optically fed subnetworks or by supplementing it with optical overlay systems. Flexibility, expandability and low costs are achieved through the standard ATM format implemented for the signals of all interactive services down to the network termination units on the subscriber side. Those signals are transmitted in the coaxial network in frequency bands above the CATV band in accordance with a multiple of the CATV channel width to ensure that the modulation and demodulation is implemented in a cost-efficient manner while providing ‘bit rate on demand’ for a suitably high number of subscribers. Separation of the network termination unit from the customer premises equipment enables a flexible, cost-efficient subscriber configuration to be selected, existing domestic wiring to be used and several completely different subscriber terminals to be simultaneously connected.     

实用化的ATM接入交换机

ＡＴＭ技术的核心是ＡＴＭ交换,ＡＴＭ交换的实现有多种方法,本文介绍一种实用的ＡＴＭ交换机,它具有结构简单,升级容易,配置灵活的特点,可广泛应用于宽带接入网中。     

Voice/data channel access integration in TDMA digital cellularnetworks

The integration of digital data capabilities in the soon to be widely deployed digital cellular networks, which were primarily designed for voice communications, offers a low-cost way to capture the large and ever growing market for mobile data services. The authors propose and evaluate a multiaccess protocol for integrating data traffic in the E(nhanced)-TDMA voice system with digital speech interpolation, which is an enhancement of the emerging North American digital cellular standard. The proposed, protocol combines random access with slot reservation mechanisms to statistically multiplex data packets with speech spurt packets over the shared terminal-to-base air channel. The integrated protocol requires no modification in the voice access protocol used in the E-TDMA system, and can attain performance close to that of an ideal voice/data multiplexer. Furthermore, the protocol may enable multislot assignment per TDMA frame to match the throughput needs of individual data terminals, and can accommodate application-dependent data transmission priorities     

Evaluation and comparison of cell loss and delay models for ATM multiplexers

Among several models that are available to represent the aggregate cell flow generated by on–off sources at an ATM multiplexer (either at an access or a switching node), the Interrupted Bernoulli Process (IBP) is characterized by particular simplicity and analytical tractability. The superposition of sources individually modeled as an IBP, whose cells enter a common buffer, is considered in this paper. The main goal is to compute approximations of two basic Quality of Service (QoS) indicators, namely, cell loss rate, whose analytical computation has been already presented in previous works, and the rate of cells exceeding a specified delay, whose presentation constitutes the theoretical novelty of the paper. Analytical expressions of these two quantities are given for homogeneous sources, i.e., possessing the same statistical parameters and QoS requirements. The analytical formulation is carefully evaluated by comparing the results obtained with others presented in the literature and with simulation results; in the latter, the actual cell arrival process is generated by means of a Markov Modulated Deterministic Process (MMDP) model of the on–off sources. Several comparisons are performed for different offered loads and by varying the buffer length, which show the effectiveness and the limits of the technique under investigation.     

话音ATM交换的实现─—ATM论坛电路仿真系列建议

近年来，随着ATM主干网络的建设和发展，研究ATM对现有通信业务的支持方式和适配技术是目前ATM技术研究的热点之一。话音ATM交换在降低话音通信成本和简化网络操作环境等方面提供了大量的技术手段，并且支持在单一网络环境中的多种综合业务传输。ATM论坛制定了电路仿真系列建议，话音ATM交换的技术已经基本成熟。文章通过对话音ATM交换在实现和优化方面的技术进行分析，并提出一种基于NativeModeATM的话音通信方式。