Packet power-B-ISDN and the asynchronous transfer mode

The vast expense of installing a new infrastructure for the ISDN has now been accepted. The new type of network should be able to carry not only existing services of voice communication, but also those that might be needed well into the future such as data, facsimile and pictures. The authors discuss the use of the broadband ISDN with the asynchronous transfer mode based on fast packet switching     

Integrated voice and data communications overview

The author reviews architectures and traffic characteristics for voice and data communications, and addresses important issues in integrated voice and data communications. He discusses some possible methods of integrating voice and data and presents an example of implementing integrated voice and data communications. He considers ISDN (integrated services digital network) as a vehicle for supporting integrated services including voice and data as well as image and video. Although the concern is mainly with switched networks, some of the concepts discussed are applicable to both switched and special-services networks     

ISDN: a snapshot

A snapshot of the present status of ISDN (integrated services digital network) is presented in terms of standardization efforts, field trials and demonstrations, implementations and services, and equipment and devices. A review of opinions and controversies as well as future trends is also given. The authors emphasize the importance of the worldwide standardization effort and discuss the organizations that are responsible for establishing such standards. It is pointed out that, with the limitation and inflexibility of the narrowband ISDN and the broadband ISDN, issues for higher-rate services have become prominent. For broadband services, the problem is not merely increasing the speed of the operation. It affects the compatibility of switching technology, the workability of the local loop arrangement, the availability of rate adaption, and the efficiency of bandwidth utilization. Although some basic principles of narrowband ISDN can be carried to broadband ISDN, the technology is quite different. For example, the interconnection and transmission problems of video, HDTV, (high-definition television), and high-speed data are different from those of voice. Thus, the standard 64-kb/s B channel itself, the fundamental rate of ISDN transmission, appears inadequate for wideband services. At present, the solution is to establish the multiples of 64 kb/s for accommodation of broadband or higher rates     

A narrowband, high capacity integrated voice/data mobile radiosystem for dispatch-related broadcast applications

This paper presents the design and performance analysis of a narrowband, mobile radio system optimized for dispatch-oriented broadcast applications in the 450 and 800 MHz frequency bands. The proposed system is significant since present-generation systems have proven incapable of providing the increased capacity demanded by new data services such as mobile data terminals, automatic vehicle location, and mobile facsimile. The centerpieces of the proposed design are a dynamic multiplexing technique known as packetized data, voice dedicated (PDVD) burst switching, which allows transmission of data within the silence gaps inherent in speech, and a noncausal signal processing technique called lookahead, which provides the data sources with advance knowledge of where the silence gaps will occur. Simulation results are given for two dispatch-oriented broadcast applications with widely differing traffic statistics, showing the flexibility and efficiency of the proposed system. The results show that for either application, the proposed integrated voice/data system can be retrofitted into existing 450 and 800 MHz public and private land mobile radio channels and, compared to conventional voice-only systems, can provide the user with full data services plus a tripling of voice capacity     

Personalizing ISDN

It is argued that making integrated services digital networks (ISDNs) more popular among personal computer users is essential for ISDN to prosper. Users in offices, businesses, and at home form a large potential ISDN market. Existing ISDN interface modules such as ISDN adapter boards for personal computers, are limited to ISDN features and can hardly handle the various needs of personal users. An ISDN interface module for personal computers must be designed to handle various applications and provide any-to-any communications. An ISDN personal computer interface developed to handle digital and analog communication protocols and flexibly combine resources is described     

Facsimile today

Over the past few years, facsimile has become the most popular form of business text communication. The paper gives a brief outline of the way in which a facsimile terminal operates and explains the various scanning and printing technologies in use today. The use of facsimile on the integrated services digital network (ISDN) is also considered     

The role of ISDN in data networking

The integrated services digital network (ISDN) offers on-demand switched end-to-end digital connectivity over the wide area, enabling the integration of both voice and data services over a common core network. This paper considers the role of ISDN in data networking, both as the core transport network and as a means of enhancing resilience in a mixed-technology data solution, complementing other data network technologies. The issues associated with data transport based on an ISDN solution are considered, and include security, bandwidth utilisation, scalability and the management of ISDN-attached devices. Optimising the use of ISDN networks for supporting the most prevalent routed and routeing protocols is also discussed.     

Software Protocol for Handling ISDN in the Packet-Switched Network

The Integrated Services Digital Network (ISDN) provides basic architecture for existing, as well as future residential plus business communications. ISDN overlayed with CCS#7 of a digital PSTN (Public Switched Telephone Network) can be the ultimate, ubiquitous network for circuit switch (voice, data), packet switch (voice, data), and private line (voice, data) applications. Assuming that the present ISDN has to interwork in the present physically separate overlayed networks (voice and data), significant problems are expected to emerge for designing hardware and linking softwares for handling packet traffic. In this paper, the software-related problems, when ISDN packet distribution nodes have to handle an ISDN interface, will be outlined with an ISDN software protocol solution. An approximation of the delay involved in the telephone switching system which is part of ISDN processing as well as the delay for the interface gateways, the HOST computer nodes, and the LAN and WAN computer nodes will be identified and formulated to reflect the total performance measure defined. Major emphasis is given to flow and congestion control performance measures in the ISDN Gateways, which are analyzed and simulated with the assistance of the basic delay table transfer software model developed for the IMPS and gateways in the ARPANET, MILNET, and MINET. The performance evaluation of this basic ISDN interfacing software, which only involved one ISDN level, i.e., the HOST or gateway and its related subnetworks, is simulated on sections of these networks to illustrate its congestion control effectiveness. There are six mathematical software techniques to account for end-to-end delay, which form the basis for the solution to these ISDN software-hardware problems in the Interface Gateways connecting the electronic switch to the computer network components.     

Support of Existing Data Interfaces by the ISDN

During the past decade, the opportunity has arisen to economically combine data and voice services onto a single system, the integrated services digital network (ISDN). Studies in CCITT have led to the production of a set of Recommendations covering aspects of the ISDN, including the customer terminal interface. Inevitably, there are significant differences between the customer terminal interfaces recommended for dedicated data networks and that proposed for the ISDN. To ensure a smooth transition towards the introduction of ISDN based services, the CCITT have published recommendations describing how existing terminal interface designs may be connected to an ISDN. These recommendations are the subject of this paper.     

Video and image applications on narrowband and broadband isdn

Two major ISDN applications which will undoubtedly affect world-wide telecommunications in the coming decade are discussed. They are: (1) video transmission and (2) image transmission. Brief reviews of videophone chronicle and the current video coding technologies are presented. The application of videophones using p × 64 (CCITT coding algorithm up to 1·5 Mb/s) and the DCT (discrete cosine transform) algorithm for narrowband ISDN are discussed. Broadcast TV quality DS3-45 MB/s video codecs are also briefly discussed as a probable videophone system in the broadband ISDN era. The explosive growth of facsimile services is reviewed, and the progress of image coding technologies and their standards are covered. The prospects of high resolution image transfer systems with ISDN are addressed.     

光纤综合业务局域网

本文扼要地介绍了把光通信技术和计算机技术组合应用,以光纤为传输介质,组成一个以一根光纤同时传输图象信息、话音信息、文字真迹信息和数据信息等不同业务的综合业务局域网。并叙述了网络的拓扑形式、功能、用途及光端机的构成,计算机的作用等。     

CCITT Recommendations on the ISDN: A Review

This paper gives a brief overview of the I-Series of Recommendations on the integrated services digital network (ISDN) developed by the International Telephone and Telegraph Consultative Committee (CCITT). This set of Recommendations is printed in the CCITT "Red Book." The I-Series Recommendations represent the first major step towards worldwide harmonization of the fast-growing digital network capabilities in support of multiservice (voice, data, and image) user applications. Over 25 different Recommendations set up standard guidelines and features for service capability, network architecture, and user-network interfaces in the ISDN.     

适配于ISDN的综合业务局域网设计

现有ＬＡＮ的传输能力在很大程度上可满足传输综合业务的要求，现有ＬＡＮ适配于ＩＳＤＮ的直接方法是在ＬＡＮ上实现ＩＳＤＮ功能，从而达到ＬＡＮ工作站与ＩＳＤＮ间业务的完全互通，在ＬＡＮ上实现ＩＳＤＮ功能的方案是：（１）在ＬＡＮ上增加综合业务传输接口，该接口不同于ＬＡＮ软件提供的接口，具有实时性，而且该接口的设计应使ＬＡＮ应用与综合业务应用间互相独立；（２）开发在工作站上与ＬＡＮ应用软件并发运行的综合业务     

Network control method and human-machine interface design for ISDNmultimedia terminals

A human-machine interface has been created for an integrated services digital network (ISDN) network control unit (I-NUU). I-NUI is a sophisticated terminal device that allows a voice communication channel and two data channels to be connected through an ISDN I-series interface. ISDN communication functions and network control operations were analyzed to determine the required characteristics of I-NCU. I-NCU features the minimum number of control buttons and a liquid crystal display. Visual and audible information are used to keep the operator fully informed about the state of the communication channels     

Implementation of a broadband integrated services hybrid network

The issues involved in the design of a broadband integrated services digital network (B-ISDN), that utilizes optical fibers in the subscriber loop, are considered. A hybrid scheme that provides integrated access to ISDN and broadband services by delivering voice/data signals in a digital format while using an analog format for full-motion video services to subscribers is proposed. The discussion covers planning for a B-ISDN, the system concept, implementation, the loop fiber network, subscriber equipment, and cost comparison and analysis     

Analysis of packet-switched data in a new basic rate user-networkinterface of ISDN

We present here an exact method for analyzing the queueing behavior of packet-switched data in a new basic rate user-network interface of ISDN. The new interface of ISDN in this paper adopts statistical multiplexing for providing integrated voice and data services. In order to properly represent the arrival of multirate data service, this interface assumes that the data packet input process is in batch Poisson. Furthermore, it is modeled by multiple synchronous servers with priority queues and finite waiting room with complete rejection strategy. The analytical method, with an application of the residue theorem in complex variable, can accurately obtain the data performance measures     

Applications of voice processing to telecommunications

The ways in which people communicate are changing rapidly. The options are many and diverse, ranging from voice calls over wireless networks, to video calls over the conventional wired network, ISDN video, FAX, e-mail, voice mail, beeper services, data services, audio teleconferencing, video teleconferencing, and so-called scribble phone service (transmission of arbitrary handwritten input). This revolution in communications is being fueled by several sources, including the availability of low-cost, low-power, computation in both DSP and RISC chips, larger and cheaper memory chips, improved algorithms for communications (e.g., modems, signaling) and signal processing, and finally the creation of world-wide standards for transmission, signal compression, and communication protocols. The broad goal of the communications revolution is to provide seamless and high-quality communications between people (or groups of people), anywhere, anytime, and at a reasonable price. Although there are many technologies that form the bases for the communications environment of the twenty-first century, one of the key technologies for making the vision a reality is voice processing. In this paper we attempt to show, by example, how voice processing has been applied to specific problems in telecommunications, and how it will grow to become an even more essential component of the communications systems of the twenty-first century