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Dsl Primer

Contents
1. Introduction
1.1 The Fundamental Problem of Communications 5
1.2 The Transmission Medium-Attenuation Constraints 9
1.3 The Transmission Medium- Interference Constraints 12
1.4 The Transmission Medium- Bandwidth Constraints 13
1.5 DSL Keeps Unshielded Twisted Pair (UTP) Copper Cable
Attractive as a Premises Transmission Medium 18
1.6 A Brief History of DSL 21
1.7 Program 22
2. xDSL Modems: Fundamentals and Flavors
2.1 The Simple DSL Transceiver 24
2.2 The Many Flavors of DSL 28
2.2.1 IDSL 28
2.2.2 The HDSL Family: HDSL, SDSL, MSDSL and HDSL2 28
2.2.3 The ADSL Family: ADSL, MDSL, RADSL and
Splitterless DSL 33
2.2.4 VDSL 36
3. The Role of DSLAMsers 37
4. Virtual DSL: The Role of the DSL Simulator 39
5. Standards 46
6. Digital Subscriber Line - DSL Glossary 48
Bibliography 95

Index of Illustrations
Figure 1-1 Source, User pair with information 5
Figure 1-2 Representations of information 6
Figure 1-3 Examples of sources and users generating/desiring "data" 6
Figure 1-4 Source, transmission medium, user 7
Figure 1-5 Disturbance travelling in transmission medium 7
Figure 1-6 The model which represents the fundamental problem of
Communications 8
Figure 1-7 Input data signal attenuating as it propagates down a
transmission medium 10
Figure 1-8 Regenerating and repeating an attenuated signal in order to
reach user 11
Figure 1-9 Example transfer function of a transmission medium 14
Figure 1-10 Binary data from source represented by impulse train put into
transmission medium by transmitter. Impulses are T seconds apart 15
Figure 1-11 Input signal is positive impulse. Resulting output signal shows
time dispersion 16
Figure 1-12 Cost trends of common transmission media 19
Figure 2-1 A typical DSL Transceiver block diagram 25
Figure 2-2 Transmitter of digital transmission...