TABLE OF CONTENTS 1. Introduction ... 1 --- PART I: DSL Technologies --- 2. DSL Technologies 2.1. Introduction ……….……….. 2.2. DSL environment ……….. 2.3. Crosstalk ………... 2.3.1. NEXT ……….. 2.3.2. FEXT ………. 2.3.3. FSAN method……….. 2.4. Shannon formula ...……… 2.5. Conclusions ……….. 5 7 9 9 10 11 12 14
--- PART II: Bit-allocation and DSM Theory ---
3. Bit-allocation for a Single-User System
3.1. Fundamental concepts behind the actual bitloading implementation
3.1.1. “ADSL triangle”: margin, gain, PSD ……….
3.1.2. The triangle balancing constructor: the ATU ……….
3.1.3. Margin explanation ……….
3.1.3.1. Right setting for the margin parameters ………..
3.2. Bitloading : ADSL initialization………
3.2.1. Basic relation………... 3.2.2. Practical steps……….. 3.2.3. Summarising ………... 3.3. Bitswap……….. 3.3.1. Basic relation………... 3.3.2. Practical steps ………. 3.3.3. Limitations ……….. 15 16 17 20 23 26 26 29 30 37 37 38 39
3.3.4. Summarising ………... 3.4. Conclusions ………... Appendix 3 ………... 39 42 44
4. Optimal Bitloading for Single-User System and for Multiple-User System 4.1. Waterfilling Algorithm for a Single-User system ……….
4.1.1. Waterfilling with no PSD constraints ……….
4.1.1.1. Rate Maximization ………..
4.1.1.2. Margin Maximization ………..
4.1.2. Waterfilling with PSD constraints ………..
4.1.2.1. Rate Maximization ………..
4.1.2.2. Margin Maximization ……….
4.1.3. Waterfilling for finite bit granularity ………..
4.1.3.1. Rate Maximization with no PSD constraint …………
4.1.3.2. Rate Maximization with PSD constraint ………. 4.2. Flat shape of PSD for the waterfilling algorithm ………..
4.2.1. Demonstration ……….
4.2.2. Conclusions ……….
4.3. Distributed power control for DSL (Multi-User System Design) …
4.3.1. Multi-User environment, Rate Region ………...
4.3.2. Power parameter: Near-Far problem, PBO, Politeness, Boosting ………..
4.3.3. Advantages of distributed power control algorithm ………..
4.3.4. Competitive optimality, the Nash equilibrium ………...
4.3.5. Distributed power control algorithm ………..
4.4. Conclusions ………... 47 48 49 49 50 51 51 51 52 52 53 53 56 57 57 60 65 67 67 71 5. DSM Technique 5.1. Introduction: why DSM ………..………..
5.2. All the DSM levels and algorithms ………...
5.3. DSM level-1 ……….. 5.3.1. Introduction ………. 73 79 84 84
5.3.2. DSM level-1 explanation ………
5.3.3. Practical implementation of DSM level-1 in the actual modems: Adaptation modes in the transceivers ……….
5.3.4. DSM level-1 and spectral compatible masks ………..
5.3.5. DSM level - 0.5 - 0.75 -1 ………
5.3.6. DSM level-1 applied to different deployment scenarios ……
5.3.7. Impact of DSM on stability of DSL lines ………...
5.4. Conclusions ………... Appendix 5……… 87 93 95 97 97 100 101 102
--- PART III: Experimental Analysis ---
6. Dynamic Simulation Tool
6.1. General overview ………..
6.2. Description of the main blocks and capabilities ………... 6.2.1. Channel ………...
6.2.2. SourceList ………...
6.2.3. Simulation Manager (simManager) ………
6.2.4. ADSL modem ……….
6.2.5. Noise ………...
6.2.6. Failures ………...
6.3. Implemented Algorithms for Performance Measurements ..……….
6.4. Conclusions ………... 107 110 110 112 112 113 118 119 120 122 7. Performance Measurements
7.1. Simulation Environment Setup ……….
7.1.1. Approximations ...
7.1.2. Fixed parameters and methods ………...
7.1.3. Parameter Combinations ………. 7.1.3.1. Scenarios ………. 7.1.3.2. Length Distributions ……… 7.1.3.3. Noises ……….. 124 125 126 127 127 128 130
7.1.3.4. DSM Percentage ………..
7.1.3.5. Target Bitrate ………...
7.2. Performance Results ..………...
7.2.1. Plot used ………..
7.2.2. DSM Percentage ……….
7.2.3. Target bitrate: Boosting effects ….………..………...
7.2.4. CO Unbunched ………... 7.2.4.1. Coverage………... 7.2.4.1.1. European Network ……… 7.2.4.1.1.1. Noise effect .………..… 7.2.4.1.1.1.1. Single noise .……….. 7.2.4.1.1.1.2. Noise combination ………. 7.2.4.1.2. American Network ……… 7.2.4.1.2.1. Noise effect ..………. 7.2.4.1.2.1.1. Single noise ………... 7.2.4.1.2.1.2. Noise combination ………. 7.2.4.1.3. Conclusions ………...
7.2.4.2. Loop Length reach ………..
7.2.4.2.1. European Network ……… 7.2.4.2.2. American Network ……… 7.2.4.2.3. Conclusions ………... 7.2.5. CO/RT ………. 7.2.5.1. European Network ………... 7.2.5.2. American Network ……….. 7.3. Result Considerations ………...
7.3.1. Characterisation of the topology deviance with respect to the average value ………..
7.3.2. Algorithm Convergence: stability problem ………
8. Conclusions ……….. Bibliography ……… 132 132 133 133 135 137 139 139 139 141 141 145 148 149 149 154 156 157 157 160 163 164 165 167 169 169 175 180 187
