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Digital Switching Systems, I.E., System Testing and Accep- Tance and System Maintenance and Support
SSyyed Riifffat AAlli DDiiggiittaall SSwwiittcchhiinngg SSyysstteemmss ((Syystemm Reliaabbiilliittyy aandd AAnnalysis) Bell Communications Research, Inc. Piscataway, New Jersey McGraw-Hill, Inc. New York • San Francisco • Washington, DC. Auckland • BogotA • Cara- cas • Lisbon • London Madrid • Mexico City • Milan • Montreal • New Delhi San Juan • Singapore • Sydney • Tokyo • Toronto 2 PREFACE The motive of this book is to expose practicing telephone engineers and other graduate engineers to the art of digital switching system (DSS) analysis. The concept of applying system analysis techniques to the digital switching sys- tems as discussed in this book evolved during the divestiture period of the Bell Operating Companies (BOCs) from AT&T. Bell Communications Research, Inc. (Bellcore), formed in 1984 as a research and engineering company support- ing the BOCs, now known as the seven Regional Bell Operating Companies (RBOCs), conducted analysis of digital switching system products to ascertain compatibility with the network. Since then Bellcore has evolved into a global provider of communications software, engineering, and consulting services. The author has primarily depended on his field experience in writing this book and has extensively used engineering and various symposium publications and advice from many subject matter experts at Bellcore. This book is divided into six basic categories. Chapters 1, 2, 3, and 4 cover digital switching system hardware, and Chaps. 5 and 6 cover software ar- chitectures and their impact on switching system reliability. Chapter 7 primarily covers field aspects of digital switching systems, i.e., system testing and accep- tance and system maintenance and support. Chapter 8 covers networked aspects of the digital switching system, including STf SCP, and AIN. -
PORTABLE MBA in PROJECT MANAGEMENT the Portable MBA Series
PORTABLE MBA in PROJECT MANAGEMENT The Portable MBA Series The Portable MBA, Fourth Edition, Robert Bruner, Mark Eaker, R. Edward Freeman, Robert Spekman, Elizabeth Teisberg, and S. Venkataraman The Portable MBA Desk Reference, Second Edition, Nitin Nohria The Portable MBA in Economics, Philip K. Y. Young The Portable MBA in Entrepreneurship, Second Edition, William D. Bygrave The Portable MBA in Entrepreneurship Case Studies, William D. Bygrave The Portable MBA in Finance and Accounting, Third Edition, John Leslie Livingstone and Theodore Grossman The Portable MBA in Investment, Peter L. Bernstein The Portable MBA in Management, Second Edition, Allan R. Cohen The Portable MBA in Market-Driven Management: Using the New Marketing Concept to Create a Customer-Oriented Company, Frederick E. Webster The Portable MBA in Marketing, Second Edition, Alexander Hiam and Charles Schewe The Portable MBA in New Product Development: Managing and Forecasting for Strategic Success, Robert J. Thomas The Portable MBA in Psychology for Leaders, Dean Tjosvold The Portable MBA in Real-Time Strategy: Improvising Team-Based Planning for a Fast-Changing World, Lee Tom Perry, Randall G. Stott, and W. Norman Smallwood The Portable MBA in Strategy, Second Edition, Liam Fahey and Robert Randall The Portable MBA in Total Quality Management: Strategies and Techniques Proven at Today’s Most Successful Companies, Stephen George and Arnold Weimerskirch PORTABLE MBA in PROJECT MANAGEMENT EDITED BY ERIC VERZUH John Wiley & Sons, Inc. This book is printed on acid-free paper. ➇ Copyright © 2003 by John Wiley & Sons, Inc. All rights reserved. Published by John Wiley & Sons, Inc., Hoboken, New Jersey. Published simultaneously in Canada. -
In What Way Is Stored Program Control (SPC) Superior to Hardwired Control?
TELECOMMUNICAIONS SWITCHING SYSTEMS AND NETWORKS 1. How are switching systems classified? In what way is stored program control (SPC) superior to hardwired control? ELECTRO MECHANICAL SWITCHING SYSTEM Limited capability Virtually impossible to modify them to provide additional functionalities. 1. STROWGER/ STEP BY STEP SYSTEM Control functions are performed by circuits associated with the switching elements in the system. 2. CROSSBAR SYSTEM Have hard-wired control sub-systems which use relays and latches. ELECTRONIC SWITCHING SYSTEMS Control functions are performed by a computer or a processor; Also called stored program control (SPC) system. 1. SPACE DIVISION SWITCHING A dedicated path is established between the calling and the called subscriber for the entire duration of the call. Technique used in Strowger and crossbar systems. 2. TIME DIVISON SWITCHING Sampled values of speech signals are transferred at fixed intervals; May be analog or digital. A. ANALOG SWITCHING - The sampled voltage levels are transmitted as they are. B. DIGITAL SWITCHING - The sampled voltage levels are binary and transmitted. SPACE SWITCHING - If the coded values are transferred during the same time interval from input to output. TIME SWITCHING - If the values are stored and transferred to the outputat a later time interval. COMBINATION SWITCHING - Combination of time and space switching. STORED PROGRAM CONTROL HARDWIRED CONTROL Features properties changed through programming, It requires physical changes to wiring, which can be done in PBX system remotely. strapping etc which means it cannot be done remotely. Do not require gthat much of space and do not Equipments require more space & constant adjustment require constant adjustment and cleaning. and cleaning. -
Switching Relations: the Rise and Fall of the Norwegian Telecom Industry
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by NORA - Norwegian Open Research Archives Switching Relations The rise and fall of the Norwegian telecom industry by Sverre A. Christensen A dissertation submitted to BI Norwegian School of Management for the Degree of Dr.Oecon Series of Dissertations 2/2006 BI Norwegian School of Management Department of Innovation and Economic Organization Sverre A. Christensen: Switching Relations: The rise and fall of the Norwegian telecom industry © Sverre A. Christensen 2006 Series of Dissertations 2/2006 ISBN: 82 7042 746 2 ISSN: 1502-2099 BI Norwegian School of Management N-0442 Oslo Phone: +47 4641 0000 www.bi.no Printing: Nordberg The dissertation may be ordered from our website www.bi.no (Research - Research Publications) ii Acknowledgements I would like to thank my supervisor Knut Sogner, who has played a crucial role throughout the entire process. Thanks for having confidence and patience with me. A special thanks also to Mats Fridlund, who has been so gracious as to let me use one of his titles for this dissertation, Switching relations. My thanks go also to the staff at the Centre of Business History at the Norwegian School of Management, most particularly Gunhild Ecklund and Dag Ove Skjold who have been of great support during turbulent years. Also in need of mentioning are Harald Rinde, Harald Espeli and Lars Thue for inspiring discussion and com- ments on earlier drafts. The rest at the centre: no one mentioned, no one forgotten. My thanks also go to the Department of Innovation and Economic Organization at the Norwegian School of Management, and Per Ingvar Olsen. -
Telecommunication Switching Networks
TELECOMMUNICATION SWITCHING AND NETWORKS TElECOMMUNICATION SWITCHING AND NffiWRKS THIS PAGE IS BLANK Copyright © 2006, 2005 New Age International (P) Ltd., Publishers Published by New Age International (P) Ltd., Publishers All rights reserved. No part of this ebook may be reproduced in any form, by photostat, microfilm, xerography, or any other means, or incorporated into any information retrieval system, electronic or mechanical, without the written permission of the publisher. All inquiries should be emailed to [email protected] ISBN (10) : 81-224-2349-3 ISBN (13) : 978-81-224-2349-5 PUBLISHING FOR ONE WORLD NEW AGE INTERNATIONAL (P) LIMITED, PUBLISHERS 4835/24, Ansari Road, Daryaganj, New Delhi - 110002 Visit us at www.newagepublishers.com PREFACE This text, ‘Telecommunication Switching and Networks’ is intended to serve as a one- semester text for undergraduate course of Information Technology, Electronics and Communi- cation Engineering, and Telecommunication Engineering. This book provides in depth knowl- edge on telecommunication switching and good background for advanced studies in communi- cation networks. The entire subject is dealt with conceptual treatment and the analytical or mathematical approach is made only to some extent. For best understanding, more diagrams (202) and tables (35) are introduced wherever necessary in each chapter. The telecommunication switching is the fast growing field and enormous research and development are undertaken by various organizations and firms. The communication networks have unlimited research potentials. Both telecommunication switching and communication networks develop new techniques and technologies everyday. This book provides complete fun- damentals of all the topics it has focused. However, a candidate pursuing postgraduate course, doing research in these areas and the employees of telecom organizations should be in constant touch with latest technologies. -
Introduction to Telecommunication Network
Pilsung Taegyun AB A Fathur Afif Hari Gary Dhika April Mulya Yusuf AB A A A AB AB AB AB Anin Rizka A B Dion Siska Mirel Hani Airita AB AB AB AB AB www.telkomuniversity.ac.id Stored Program Control Course Number : TTH2A3 CLO : 3 Week : 8 www.telkomuniversity.ac.id Media Gateway on NGN • Media Gateway (MG) – On Transport plane that connects different type of network – Trunk Gateway, connects packet-based network with trunk network from PSTN or ISDN – Access Gateway, provides services to CPE – Residential Gateway, connects packet-based network with analog network • Signaling Gateway (SG) – Transforming signaling format, ex. SIP SS7 • Media Gateway Controller (MGC) – Control Media Gateway and Signaling Gateway – aka. Soft Switch (call setup for multimedia communication, detect and manage events, and manage media gateway based on configuration) – Use MGCP (MGC Protocol) from ITU-T or Megaco from IETF www.telkomuniversity.ac.id Layers in NGN 4 www.telkomuniversity.ac.id Crossbar Switch • Electro-mechanical switch by using relay contact • Numbers are stored in register to establish a call by activating several relay. This activation is done by marker • Marker will become SPC (Stored Program Control) www.telkomuniversity.ac.id Unit Interface for Digital SPC www.telkomuniversity.ac.id What is SPC? SPC (Stored program control) is: • a telecommunications technology used for telephone exchanges • controlled by a computer program stored in the memory of the switching system • SPC was the enabling technology of electronic switching systems (ESS) developed -
Design of a Circuit for Remote Control of Multiple Devices Using DTMF Encoder and Decoder
International Journal of Scientific and Research Publications, Volume 3, Issue 12, December 2013 1 ISSN 2250-3153 Design of a Circuit for Remote Control of Multiple Devices using DTMF Encoder and Decoder Haimanti Chakraborty*, Prof. (Dr.) Prabir Banerjee* * Department of Electronics & Communication Engineering, Heritage Institute of Technology, Kolkata, India frequencies that will be transmitted via an analog communication Abstract- With the advancement in technology, the number channel or network like a telephone line. It was developed of electronic devices in our day-to-day lives has increased to by Western Electric and introduced by AT&T in 1963. During its make life simpler. So a necessity to construct a Universal development, unique individual frequency filters were chosen Remote System that will easily control all these devices from a carefully so that the tones could easily travel via the telephone distance will not only reduce the complexity of handling the lines (the maximum guaranteed bandwidth for a standard number of devices simultaneously, but also save power. telephone line extends from around 300 Hz to 3.5 kHz). DTMF This paper presents a successfully developed hardware was not intended for data transfer, rather for control signals only. of a Universal Remote Control System using DTMF (Dual- With a standard DTMF encoder/decoder, it is possible to signal Tone Multi-Frequency) tones as the control signals. The at a rate of around 10 tones/signals per second. uniqueness of DTMF is that it is simple to generate and noise- The DTMF keypad is laid out in a 4x4 matrix, with two immune. This system was also implemented using GSM links frequencies (each row representing a low frequency and each besides the wired channel, the main advantage of it being that it column representing a high frequency) played simultaneously by helps in controlling devices located at any part of the world or a standard home phone/fax or mobile phone. -
The American Telephone and Telegraph Company Divestiture: Background, Provisions, and Restructuring
Report No. 84-58 E I -. <I?....*- ".YII. -n, -- THE AMERICAN TELEPHONE AND TELEGRAPH COMPANY DIVESTITURE: BACKGROUND, PROVISIONS, AND RESTRUCTURING b Y Angele A. Gilroy Specialist in Industrial Organization Economics Division COLLECTION WKI HEKN !CNTUCKY LIBRARY April 11, 1984 11 i :::A L.'~~-l.ii.e makes jucn research available. without parti- ::;I.. in lr:m\ !orrns inc!uding studies. reports. cornpila- ;,)I!., I!:<?\[>. :md l:a~kqroi~ndhrietings. Cpon request. CRS .. ., :i ~ !>!r::z:rrir.e.;in ann1~-zingle+slative proposals and -tl:..b. :!nd in s>w;sinq the possible effects of these proposals . < :!I irie.The Ser~ice'ssenior specialists and ii,:c( r :iil.,;ii ?is are also at-aiiable for personal consultations ;xi-ir :.t>.;!?ecri\-elieid.; t~f'expertise. ABSTRACT On January 1, 1984, The American Telephone and Telegraph Company (AT&T) di- vested itself of a major portion of its organizational structure and functions. Under the post-divestiture environment the once fully-integrated Bell System is now reorganized into the "new" AT&T and seven Ladependent regional 5olding ?om- panies -- American Information Technologies Corp., 3ell Atlantic Corp., 3ell- South Corp., NYNEX Corp., Pacific Telesis Group., Southwestern Bell Corp., and U.S. West, Inc. The following analysis provides an overview of the pre- and post-divestiture organizational structure and details the evolution of the anti- trust action which resulted in this divestiture. CONTENTS ABSTRACT ................................................................ iii INTRODUCTION ............................................................ 1 1 . BELL SYSTEM CORPORATE REORGANIZATION .............................. 3 A . Predivestiture Bell System Corporate Structure ................ 3 B . Divested Operating Company Structure .......................... 5 C . Post-Divestiture AThT Organizational Structure ................ 7 11. -
MAS.632 Conversational Computer Systems
MIT OpenCourseWare http://ocw.mit.edu MAS.632 Conversational Computer Systems Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 10 Basics of Telephones This and the following chapters explain the technology and computer applica tions oftelephones, much as earlier pairs ofchapters explored speech coding, syn thesis, and recognition. The juxtaposition of telephony with voice processing in a single volume is unusual; what is their relationship? First, the telephone is an ideal means to access interactive voice response services such as those described in Chapter 6. Second, computer-based voice mail will give a strong boost to other uses of stored voice such as those already described in Chapter 4 and to be explored again in Chapter 12. Finally, focusing on communication,i.e., the task rather than the technology, leads to a better appreciation of the broad intersec tion of speech, computers, and our everyday work lives. This chapter describes the basic telephone operations that transport voice across a network to a remote location. Telephony is changing rapidly in ways that radically modify how we think about and use telephones now and in the future. Conventional telephones are already ubiquitous for the business traveler in industrialized countries, but the rise in personal, portable, wireless telephones is spawning entirely new ways of thinking about universal voice connectivity. The pervasiveness of telephone and computer technologies combined with the critical need to communicate in our professional lives suggest that it would be foolish to ignore the role of the telephone as a speech processing peripheral just like a speaker or microphone. -
CQWE Contest Packet
20___ CQ-WE LOG Sheet Callsign: ________________ Sheet _____ of _____ QSO Date UTC Band Mode Station Name Loc Years # Code Service 2020 CQ-WE LOCATION CHECK SHEET (Duplicate this sheet as needed.) Your Call___________________________ Circle one: CW PHONE DIGITAL These are the only Locations valid for this year's contest. Any additions will not be accepted. A Location Check Sheet must be filled out for each Category of operation. Enter the call letters of the first station worked for each location. Call Location Call Location Call Location __________ AC AT&T Headquarters __________ LJ AT&T Communications __________ QJ C&P Telephone Co VA __________ AE Alcatel-Lucent, Europe __________ LZ Avaya – Lincroft __________ QK Ameritech Services __________ AK Atlanta Works-Norcross __________ MD Morris Township Fac __________ QM Bell South __________ AL Allentown Works __________ MG Montgomery Works __________ QN Ohio Bell Telephone __________ AT Atlanta Works __________ MH Bell Labs-Murray Hill __________ QP Cincinnati Bell __________ BA Baltimore Works __________ MI Miami Service Ctr __________ QR Indiana Bell __________ BB PLPM Trans Eqpt __________ MN Michigan Service Ctr __________ QS Michigan Bell __________ BC Bellcore/SAIC-NJ __________ MP Minneapolis Svc Ctr __________ QT Illinois Bell __________ BH Birmingham, AL __________ MR Mountain NE Region __________ QV Southwestern Bell __________ BK Berkeley Heights, NJ __________ MS Northwest Bell Inst __________ QW Mountain States Tel __________ CA California Service Ctr __________ MT AT&T – -
WE Inter-Phones and Accessories 1915
• ,..--·~! l ? -/ t F .L_:"""; ..... ~ 1915 , . / -, iEl1@~;t!?ll~ ," cMQ)JNIE~ TCI Library: www.telephonecollectors.info Page 1 }H1sll'rn #.£/,rlrit COMPANY Inter-phones and Accessories "INTER-PHONE" is the trade name adopted by the Western Electric Company for what is commonly known as Intercommunicating Telephone Apparatus. On the following pages will be found much information of value. "e have avoided, as far as possible, the use of general or descriptive information, and have endeavored to condense all data given. Wiring diagrams are also shown. Three general types of Inter-phones-\\all, desk, and hand-set types-are furnished. Under each system are listed the types adapted for the service described. INTER-PHONE SYSTEMS The various systems for which Inter-phones are adapted are as follows: HOUSE TELEPHONE SYSTEM. Multi-station, one or two-way service. Two to three line wires. System No. 16, list on page 3. ___ TWO STATIONS ONLY. Two line wires. Batteries at each station. System No. 14, listed on page 6. TWO TO SIX STATIONS. Code ri"gings-common talking. Three to foUl' line wires. Batteries at one station only. ,-,ystem No. 15, listed on page 7. THREE TO NINE STATIONS. Selective ringing. Common talking. Batteries at one s a ion only. System TO. 11, lis on page 11. MASTER STATION and not more than twelve outlying stations. Batteries at mas er s ation only. System Ko. 12 lis~ed on page 13. NOT MORE THAN TWENTY-FOUR STATIONS. Selective ringing and talking be tween all stations. System :;\0. 1, listed on page 18. A SYSTEM ALLOWING SECRET CONVERSATIONS between certain stations, being a modification of System No. -
Intelligent Network Services
Next Generation Network Services Neill Wilkinson Copyright q 2002 John Wiley & Sons, Ltd ISBNs: 0-471-48667-1 (Hardback); 0-470-84603-8 (Electronic) 10 Intelligent Network Services 10.1 INTRODUCTION In Part 1 of this book, we examined the functional and physical character- istics of circuit switched based Intelligent Networks (INs). In this chapter, we are going to explore what these elements do by way of offering services to customers and giving carriers a flexible means of delivering new services. The IN service model was the first step to releasing service control from the hands of switch manufacturers and as such presented telecoms opera- tors with a new vehicle for realising services that enhanced the basic call control capabilities of stored program control switches. We see that this is not the end of the story for enhanced service platforms as the move to remove the final block to enhanced services, the close coupling of the stored program controller and the switch fabric, to release the potential of software driven services on packet networks. Just to refresh the reader on INs. They rely on the decoupling of a number of telephone switch functions from the stored program controller, renamed a Service Switch Point (SSP) in the IN architecture. The functions left behind in the SSP are called the Basic Call State Model (BCSM). The functions separated out are incorporated into a centralised service execu- tion environment as a Service Independent Building Block (SIB) called the Basic Call Processing (BCP) function. The services, constructed from SIBs to form a Service Logic Program (SLP), run inside this environment called the Service Logic Execution Environment (SLEE), inside a physical plat- form called the Service Control Point (SCP).