Next Generation SDH/SONET
Evolution or Revolution?
Chapter One
Introduction
To the next generation SDH/SONET
Although it is assumed that the reader has a basic understanding of the
operation of the Synchronous Digital Hierarchy (SDH) and/or the
Synchronous Optical NETwork (SONET), this book starts with a short
history of the revolutions and evolutions that have taken place during
and after the design of the SDH/SONET standards.
The conventions adopted in this book will be explained to avoid
confusion caused by the different terminology used in the SDH,
SONET, OTN and PDH standards and to provide a consistent
description of the features of the next generation SDH/SONET.
1.1 HISTORY
During the evolution of digital multiplexes, e.g. from the primary rate
multiplexes 2048 kbit/s E1 and 1544 kbit/s DS1 up to the fourth order
multiplexes 139.264 Mbit/s E4 and 274.176 Mbit/s DS4, in general
referred to as Pleisiochronous Digital Hierarchy (PDH) signals, it
became clear that the application of these multiple ... read full excerpt from Next Generation SDH/SONET: Evolution or Revolution? ebook
