Page 7 - Optical Switching And Networking Handbook
P. 7
01_200023_FM/Bates 1/17/01 10:10 AM Page vi
vi Contents
Asynchronous Transmission 58
Bit Stuffing 59
SONET: A Means of Synchronizing Digital Signals 60
SONET Line Rates 61
Why Bother Synchronizing? 63
The SONET Frame 64
Overhead 64
Inside the STS-1 Frame 67
SONET Overhead 68
Overhead 69
Line Overhead 69
Path Overhead 70
Virtual Tributaries 70
SONET Multiplexing Functions 71
Concatenation 73
Add-Drop Multiplexing: A SONET Benefit 75
SONET Topologies 76
Point-to-Point 77
Point-to-Multipoint 77
Hub and Spoke 78
Ring 78
Chapter 4 Synchronous Digital Hierarchy 81
Why SDH/SONET 83
Synchronous Communications 84
Plesiochronous 84
Synchronous Digital Hierarchy 86
Data Transmission Rates 87
Some Differences to Note 88
The Multiplexing Scheme 89
Why the Hype? 100
The Model as It Pertains to SDH 102
Chapter 5 Wave-Division Multiplexing and Dense-Wave-Division
Multiplexing 105
Growing Demands 107
What Is Driving the Demand for Bandwidth? 107
Wave-Division Multiplexing 109
Benefits of Fiber over Other Media 114
