DOI:10.1049/ree.1984.0020

出版商:IERE    

年代:1984

数据来源: IET

DOI:10.1049/ree.1984.0025

出版商:IERE    

年代:1984

数据来源: IET

摘要:

This paper reviews the evolution of digital transmission and switching in a telecommunication network, and emphasizes the importance of integration of networks and services. The concept of an Integrated Digital Network and an Integrated Services Digital Network are introduced and a brief review is given of the repertoire of transmission systems available in the United Kingdom to realize such networks. The objective of this introductory paper is to provide general background information supporting the companion papers in these special issues.

DOI:10.1049/ree.1984.0026

出版商:IERE    

年代:1984

数据来源: IET

摘要:

This paper describes the philosophy and principles of Integrated Services Digital Networks (ISDN), reviews the CCITT standards activities and outlines the plans and strategies for evolution to an ISDN.

DOI:10.1049/ree.1984.0027

出版商:IERE    

年代:1984

数据来源: IET

摘要:

Unless proper control is exercised in limiting the amplitude of jitter in future digital networks, serious degradations can arise. The important sources of jitter are identified and described. Trie manner in which jitter accumulates in a digital network is discussed with particular emphasis being given to accumulation along transmission systems. A brief review is given of the current status of jitter studies within international organizations (CCITT and CEPT).† The jitter control and specification philosophy for digital networks and equipments based on the 2048-kbit/s hierarchy is outlined.

DOI:10.1049/ree.1984.0028

出版商:IERE    

年代:1984

数据来源: IET

摘要:

The liability of a digital signal to error is one of the most significant transmission impairments experienced in a digital communication network. Consideration is given to the activities and status of studies within the International Telegraph and Telephone Consultative Committee (CCITT). The sources of interference causing errors are discussed and an introduction is given to Hypothetical Reference Connections (HRX). The internationally agreed end-to-end error performance specification for a digital connection is reviewed along with the methodology for allocating this overall objective to constituent transmission equipments operating over different media. A number of mathematical models are identified which might be adequately representative of the error characteristics to be found in real networks. Finally, measurement aspects are discussed.

DOI:10.1049/ree.1984.0029

出版商:IERE    

年代:1984

数据来源: IET

摘要:

The timing of signals and processes within integrated digital networks requires careful control in order to minimize signal degradation through the occurrence of slip. The paper discusses the slip mechanism and the alternative methods of its minimization, i.e. the use of high accuracy clocks working in a plesiochronous mode or the phase locking of nodal clocks to a reference clock.The progress of relevant international standardization activities in CCITT is discussed, particularly in relation to the specification of reference clocks, limits for tolerable slip performance and equipment design limits to cater for wander and jitter in the network.The approach taken to timing control within the international network and to synchronization techniques adopted by certain administrations with respect to synchronization methodology and network topology, clock configurations and interconnecting timing links are also given.

DOI:10.1049/ree.1984.0030

出版商:IERE    

年代:1984

数据来源: IET

摘要:

This paper considers the performance evaluation of the future Integrated Services Digital Network. Emphasis is given to both the measurement and the instrumentation necessary to quantify the most important digital transmission impairments, jitter and errors. The trend towards non-intrusive measurement and automated testing made possible by advances in digital technology is reviewed

DOI:10.1049/ree.1984.0031

出版商:IERE    

年代:1984

数据来源: IET