B-ISDN internetworking

The internetworking of broadband integrated services digital networks (B-ISDNs) with metropolitan area networks (MANs), local area networks (LANs), ISDNs, and frame relay networks is examined. The status of some current International Consultive Committee for Telephone and Telegraph (CCITT) recommendations are reviewed     

向宽带综合业务数字网进军

本文介绍了通信发展的状况和 B-ISDN 的特性,重点提出现有局域网、N-ISDN 网络与B-ISDN 网络互连的策略,以及面向21世纪宽带通信网的网络结构。最后简述了通信业务的发展趋势及利用 ATM/B-ISDN技术改造中国现有通信网的设想。     

B-ISDN signalling standards

This paper identifies what is meant by standards and their value in the B-ISDN signalling environment. It goes on to identify the international bodies that are responsible for producing these standards and gives details of their output so far and what their future plans are expected to deliver. Consideration of the various drivers (commercial, technological, regulatory, etc) that have shaped the output and workplan is also given. In addition, there is an examination of the emerging collaborative activity and its value in limiting the potentially vast number of standards and any duplication.     

B-ISDN中的无连接业务

以ATM交换为基础的B-ISDN提供高速、面向连接、分组长度固定的信元交换.当代PC和高速LAN的发展需要面向连接的ATM网络传输无连接业务.本文重点介绍ATM网络中无连接业务的分类、协议结构和具体实现形式.     

UMTS integrated with B-ISDN

Since, by the turn of the century, a mobile terminal will be involved in 50 percent of all calls, it is critical that the integration of the fixed and mobile telecommunication systems succeeds. This will require that B-ISDN support some features necessary to provide mobility services to the users. In the scenario discussed in the present article, the UMTS base stations are connected to a B-ISDN local exchange using the same user-network-interface (UNI) as B-ISDN fixed network terminals. Therefore, many of the aspects discussed in the article are related to the UNI     

B-ISDN architecture and protocol

The authors discuss the architecture and protocol for broadband ISDN (B-ISDN) based on the CCITT standards. The discussion attempts to address the general concept of B-ISDN architecture and protocol and, whenever possible, present alternatives and the rationale for decisions in the selection of the protocol. B-ISDN is presented as a network evolution, and the impact of the asynchronous transfer mode (ATM) on the network is described. The role of virtual channel and virtual path in B-ISDN is discussed. The B-ISDN protocol structure and lower layer functions comprising the physical, ATM, and adaptation layers are presented, and the tentative trends of signaling and traffic control for the B-ISDN are delineated     

B-ISDN multimedia workstation architecture

Technical issues involved in integrating computer and communication technologies in the broadband integrated services digital network (B-ISDN) environment are discussed. The Multimedia Environment for Remote Multiple-Attendee Interactive Decision-making (MERMAID), an ISDN-based multimedia and multiparty desktop conference system, is described. MERMAID involves B-ISDN key technologies related to multimedia and multicast protocols, and workstation architecture for groupware applications. Technical issues based on user experiences and evaluations of MERMAID over three years are presented and discussed in connection with the system's evolution in the B-ISDN environment     

B—ISDN的AAL1规程及其发展

本文首先从支持面向连接的恒定比特率业务，在收侧恢复源端定量关系，结构数据转移和比特误码及信元丢失的检测与校正等功能要求方面详细介绍了基本的ＡＡＬ１规程，然后以减少时延为为目标讨论了对ＡＡＬ１规程可能的改进方案最后介绍适于支持低比特率话音的候选的ＡＡＬ规程。     

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。     

Traffic management for B-ISDN services

A set of asynchronous transfer mode (ATM) bearer service categories, differentiated in terms of quality of service (QOS), that will support the large spectrum of applications expected in broadband integrated services digital networks (B-ISDN) is defined. The evolution of applications and the traffic requirements in B-ISDN/ATM networks are described, and the evolution of network services to address these requirements is discussed. The definition of ATM bearer service categories necessary for the economical support of initial applications and evolution to future B-ISDN services is proposed. The elements of the ATM traffic management strategy to support these service categories are presented     

B-ISDN: a technological discontinuity

The transition to B-ISDN from current networks represents a major technological discontinuity for the communications world. These discontinuities must be considered for the successful evolution of existing networks to broadband networks. The authors provide an overview of B-ISDN data transfer protocols and the services it will support. They discuss the effects of B-ISDN switching, network operations and management, signalling protocols and architectures, and networked computing     

Revenue optimization of B-ISDN networks

We consider the optimization of routing in a broadband ISDN network through the maximization of the revenue generated by the network. Two types of calls are offered to the network with different holding times and bandwidths. The routing is alternative routing and load sharing. First we state the Kuhn-Tucker conditions and show how they provide a simple routing rule based on equal marginal net revenue. We then proposed two-stage decomposition algorithm for optimizing the routing which requires a flow-deviation stage combined with the solution of a linear system of equations. We obtain simple expressions for the net path revenues and the corresponding optimal routing rule. We summarize numerical results related to the convergence of the algorithm and the structure of the optimal routing     

B-ISDN waits for photonics to deliver

A variety of photonic switching techniques have been studied from the viewpoint of expanding switching-mode throughput. The basic issue discussed is how the high bandwidths of optical devices can be applied to switching nodes. It is shown that a high time-domain bandwidth allows high-speed signal transmission without waveform distortion, a high frequency-domain bandwidth allows a system to accommodate a large number of channels, which results in a high-capacity system, and a high space-domain bandwidth allows high-density interconnections in free space and resolves the pin-out bottleneck of LSIs and multichip modules (MCMs). Photonic space-division switching, photonic ATM switching, photonic frequency-division switching, and photonic free-space switching methods are described     

欧洲B－ISDN试验网：TRIBUNE

ＴＲＩＢＵＮＥ计划是欧洲先进通信技术研究计划（ＲＡＣＥ）的一部分。此计划的目的是在欧洲为先进的通信业务，特别是宽带综合业务数字网（Ｂ－ＩＳＤＮ），建立公共基础设施。本文将简要介绍该计划的概况。     

A fault-tolerant switching network for B-ISDN

The author proposes a self-routing fault-tolerant switching network for asynchronous transfer mode (ATM) switching systems. The network has many subswitches to enhance the fault tolerance of the conventional multistage interconnection network which only has a unique path. The subswitches provide large numbers of alternative paths between switching stages and allow the network to tolerate multiple paths. The routing algorithm is quite simple. The paths can also be used to route cells under the condition that internal cell contentions occur in switching elements. A reliability analysis shows a quantitative measurement of the improvement in fault tolerance as compared with previously presented fault-tolerant networks. A performance analysis and simulation results show that the proposed network has a high level of maximum throughput. In addition, that level of throughput is maintained with reasonable cell delay even though the number of faulty components increases in the network     

多媒体技术在B—ISDN中的实现研究

本文通过对多媒体技术需求的分析，结合Ｂ－ＩＳＤＮ的基本特性，研究多媒体技术在Ｂ－ＩＳＤＮ的实现。     

Upgrading strategies for B-ISDN subscriber loops

Upgrading strategies for broadband-ISDN subscriber loops are investigated. A five-step process for optimizing phase-by-phase system upgrading from existing narrowband ISDN to future superbroadband ISDN is developed. The process is designed to be as simple as possible and to include as many environmental conditions, such as network models, subscriber capacities and associated penetrations, and cost trends for system components, as possible. A typical example is given to show the efficacy of the optimization process. It is shown that more general aspects of system upgrading can be extrapolated from the representative examples given     

ATM-layer OAM implementation issues [B-ISDN]

Some implementation issues pertaining to the asynchronous transfer mode (ATM) layer operations and maintenance (OAM) functionality are addressed. A brief summary is given of the current understanding in CCITT on ATM-layer OAM implementation. This is followed by discussions of fault management and performance management function implementations for the ATM virtual path connection and virtual channel connection. Some selected points for study are identified