Digital Subscriber Loop (DSL) technologies haveenabled millions of households to have cheapbroadband access by delivering megabits over simplecopper wires used for voice telephony in the past.This book reviews these channels which arecharacteristic of many communication channels, themodulation, coding and other communicationprinciples employed in the industry today. Inparticular, bit-loading algorithms, OrthogonalFrequency Division Multiplexing (OFDM), multiuserinterference and usage of adaptive power, modulationand coding assignment accross subscribers as well asusers is focussed upon. Further advanced alogorithmsare proposed which will guide in future faster andmore robust broadband access. The book also presentsthe first multiuser magin maximizationalgorithmwhich guarantees a the best error robustness for agroup of users sharing the same channel. All thealgorithms are dicussed first within a firmtheoretical framework of communication theory,information theory and optimization,and thenevaluated in real-life environment and subject toindustry standards thus making it useful for theresearcher as well as the practicing engineer.