Transaction-oriented applications via National ISDN

The article demonstrates how the services of National ISDN can be used to meet the demands of transaction-oriented applications in the retail industry. The data applications discussed are credit/debit authorization, inventory management, and credit account database access. Public network solutions using various National ISDN features and complementary telecommunication devices with a market focus are employed for the above applications. Further, the article discusses the evolution of telecommunications devices from a standards point of view and discusses the progress made in this area     

ISDN applications at Tenneco Gas

The evolution from analog to integrated services digital network (ISDN) telecommunication services at Tenneco Gas and the features of its telephone system are described. The results of implementing ISDN in data operations are examined. The benefits of ISDN for Tenneco are briefly summarized     

ISDN applications: their identification and development

Two efforts that are underway in the telecommunications industry to identify applications that directly relate to end-customer needs and to demonstrate the benefits of these applications are described. They are the North American ISDN Users' Forum (NIUF), sponsored by the National Institute of Standards and Technology, and the TriVista studies, sponsored by AT&T. Three user-initiated applications that have already been approved by the NIUF are described, namely, sales information management, customer service, and telemarketing. A history of the TriVista project is presented, including an overview of its methodologies and its major results to date. Three application areas identified by TriVista that have shown considerable market appeal are discussed in some detail. They are office automation, MIS help desk, and security     

A CMOS line driver with 80-dB linearity for ISDN applications

A high-performance CMOS line driver for ISDN U-interface transceiver applications has been designed and fabricated. Careful study of requirements and trade-offs affecting linearity, power efficiency, and quiescent current presented in this work has resulted in a circuit structure featuring a highly linear input/output characteristic and well-controlled quiescent current. The prototype line driver is capable of delivering a 5-V_pp signal of up tp 80 kHz to a 60-Ω load while exhibiting linearity on the order of 77 ± 5 dB and operating from a single 5-V power supply. Linearity better than 70 dB is maintained for load resistances as low as 20 Ω     

Evolution of ISDN towards broadband ISDN

Worldwide activities to evolve integrated services digital network (ISDN) into an optical-fiber-based universal broadband network have resulted in the first baseline documents, such as CCITT Recommendation I.121. The asynchronous transfer mode has been established as a key element of broadband ISDN (BISDN). The adoption of the G.707-709 recommendations on the new digital transmission hierarchy will also strongly influence further BISDN development. The author presents the current state of the BISDN discussion, especially within CCITT, briefly addressing broadband services and then concentrating on the user-network interface, as its definition is of utmost importance with respect to the introduction of a worldwide unique BISDN. Network scenarios and evolution and interworking aspects of the arising broadband realizations are also addressed     

Application profile for ISDN

The authors examine some key data processing applications to be used in conjunction with the voice and facsimile services as a platform for deploying ISDN (integrated services digital network) in North America. Special emphasis is placed on the emerging standards of both Accredited Standards Committees (ACS) T1 and X3 in an attempt to harmonize the computer and telecommunication industries towards providing the user with an integrated platform that is vendor-transparent and ubiquitous. This generic platform, which spans a large spectrum of businesses, is presented as a base context for defining user-specific needs and incubating the applications that directly relate to businesses. Distributed transaction processing, electronic data interchange, information retrieval, electronic mail, and file transfer together with seven supplementary services for voice and G4 facsimile are proposed for ISDN deployment in the marketplace. The authors describe how the relevant standards may be exercised through the various ISDN channels and emphasize the value of the North American ISDN User's Forum for commercializing this platform     

ISDN中的电磁兼容性

本文主要介绍以金属线路系统为基础的ＩＳＤＮ的电磁兼容性。讲座了用户线路、室内四线总线的敏感度和辐射干扰问题，以及它们和通信线路系统不平衡度的关系。     

The hyperbolic singular value decomposition and applications

A new generalization of the singular value decomposition (SVD), the hyperbolic SVD, is advanced, and its existence is established under mild restrictions. The hyperbolic SVD accurately and efficiently finds the eigenstructure of any matrix that is expressed as the difference of two matrix outer products. Signal processing applications where this task arises include the covariance differencing algorithm for bearing estimation in sensor arrays, sliding rectangular windowing, and array calibration. Two algorithms for effecting this decomposition are detailed. One is sequential and follows a similar pattern to the sequential bidiagonal based SVD algorithm. The other is for parallel implementation and mimics Hestenes' SVD algorithm (1958). Numerical examples demonstrate that like its conventional counterpart, the hyperbolic SVD exhibits superior numerical behavior relative to explicit formation and solution of the normal equations. Furthermore, the hyperbolic SVD applies in problems where the conventional SVD cannot be employed     

ISDN protocols for connection control

The technical details of the integrated services digital network (ISDN) access protocols for connection control are described. These protocols are the ISDN physical layer, link layer, and layer 3, which are documented in International Telegraph and Telephone Consultative Committee (CCITT) Recommendations I.430, I.441, and I.451, respectively. Other work that supports or enhances these protocols is described. In particular, the ISDN protocol reference model, how it relates to the open systems interconnection reference model, and CCITT Recommendation Q.932 on service feature control on ISDN are discussed. Possible uses of ISDN, possible evolution paths, and some understanding issues related to ISDN are also described     

Satellite ATM for broadband ISDN

This paper presents the development of satellite ATM for broadband ISDN based on the Research in Advanced Communications in Europe (RACE) CATALYST project. The purpose of the project is to develop an experimental ATM satellite link for the future B-ISDN services, particularly for the interconnections of the ATM testbeds which are in the form of broadband islands developed in Europe. Then initial ATM based B-ISDN can be introduced by interconnections of these broadband islands. An evolutionary approach has been adopted in the development of the ATM networks that the CATALYST project has developed the equipment to be able to interconnect the newly developed ATM testbeds as well as the existing networks such as DQDB, FDDI and Ethernet networks. In March 1994, the project carried out an experiment on the second demonstratoras the Laboratories of Alcatel Telespace in Nanteere near Paris to demonstrate the capability of the satellite ATM connections supporting data, voice, video and multimedia applications. This experiment provided a real system demonstration of satellite ATM for B-ISDN. In the light of the experiment, this paper presents the model and architecture of the ATM satellite equipment, studies the relevant issues and the impact of ATM-via-satellite on the applications and the protocols, and evaluates of satellite ATM based on some measured and simulated results.     

The ISDN U interface and transceiver

This paper describes the integrated services digital network (ISDN) basic rate interface (BRI) two-wire U interface and the transceiver necessary for the digital transmission of 160 kb/s of information over unshielded twisted pair transmission media. Topics discussed include the U interface structure and framing as described in the American National Standards Institute (ANSI) T1.601 specification, and the VLSI implementation of the ISDN U transceiver. Pertinent transceiver design issues addressed include the type of line code used, such as 2B1Q or 4B3T, echo cancellation, near end crosstalk, equalization and sampling rates.     

The Berkom project [ISDN]

The author describes the Berkom project of Deutsche Bundespost in Berlin which is concerned with broadband ISDN development. The main project fields are discussed in more detail. These are: telemedicine, telepublishing and broadband information systems. In particular the author discusses a personalised electronic newspaper application of telepublishing. The market prospects for broadband ISDN are also discussed     

Research on Advanced Switching Techniques for the Evolution to ISDN and Broadband ISDN

Switching techniques for packetized data and for video communications are a key element in the evolution of the central office from IDN, to ISDN, and to broadband ISDN. An evolutionary scenario, based both on a short-term and on a longterm reference architecture for the switching system, is proposed, and two advanced switching techniques for labeled switching and for diffusive video switching, respectively, are analyzed which match the above scenario well. Plans and preliminary results are also reported on experimental research through laboratory demonstrators of the two switching techniques.     

煤矿井下综合业务数字网设计

煤矿井下传输的信息有监测、监控数据、数字化语音及数字化视频信号功能，根据煤矿井下对信息综合传输的要求和煤矿井下巷道布置的特点，提出并设计了一种适合煤矿井下使用的环形网络结构——光纤混合接入网(FHAN)。FHAN中的节点称作智能接入路由器(IAR)，井下各种不同信息均通过IAR接人到主干网络进行传输。对FHAN中的简化路由算法，网络传输协议，关键节点IAR的DSP实现进行了介绍。现场实验表明本文提出的光纤混合接入网适合煤矿井下信息综合传输的要求，网络协议设计合理。     

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.