DSL has specific impairments beyond the normal metallic media considerations of attenuation and sharing of the voice telephony infrastructure. Specifically, DSL impairments include the following four topics:
Crosstalk and frequency interference
Copper impedance mismatches
These topics are illustrated in Figure 2-2 and are discussed in the following sections.
Early in the evolution of mass telephony, long loops had to be conditioned to maintain clear voice signals toward the end of the loops. Many telephone service ...