In accordance with the present invention, a loop extender for improving
the transmission of digital subscriber line (DSL) signals over a local
loop is disclosed. The loop extender includes selectable line termination
and equalization (SLTE) DSL amplification circuitry capacitively coupled
to the local loop via bypass relay switches, a plain old telephone
service (POTS) loading coil adapted to be coupled to the local loop for
improving transmission of POTS band signals over the local loop, and a
diagnostic/control unit (DCU) coupled to the local loop for receiving and
processing control signals from a central office, coupled to the bypass
relay switches via a bypass relay for controlling the bypass relay
switches, and coupled to the SLTE DSL amplification circuitry via a
plurality of switch control lines for controlling the SLTE DSL
amplification circuitry.