Abstract: A method and apparatus for low cost upgrading on demand of an optical fiber communication system without installing additional optical fiber and minimal installation of optical circuitry at destination and distribution terminals. The upgraded systems comprise an optical data loop of a plurality of destination terminals and a single intermediate terminal.

Abstract: A bidirectional telephone communication system for supporting a multiplicity of subscriber lines between a downstream distribution terminal using only two of a multiplicity of pre-existing transmission line pairs connected between an upstream distribution terminal and a downstream distribution terminal. Said system including automatic initializing and monitoring circuitry for powering up a communication link and reestablishing the link if lost.

Abstract: An improved digital loop carrier system for transporting voice and DSL data signals in the local loop. The digital loop carrier system includes a remote digital terminal having an interface terminal, a common equipment shelf for interfacing digital voice signals to the central office switch, and a plurality of copper shelves coupled to the common shelf for holding voice line-cards that convert digital voice signals into analog voice signals (and vice versa) for transport to customer premises. At least one copper shelf is configured to include an auxiliary packet data bus for connecting combination voice/DSL line-cards and at least one data uplink card. The data uplink card is coupled to the interface terminal to enable DSL data transport without impacting digital voice capabilities through the common equipment. Also disclosed is an optional Ethernet switch in the remote digital terminal for concentrating multiple DSL signals prior to transport back to the central office.

Abstract: A Bidirectional telephone communication system for supporting a multiplicity of subscriber lines at a downstream distribution terminal using only two of a multiplicity of pre-existing transmission line pairs connected between an upstream distribution terminal and the downstream distribution terminal. Standard PCM data packets are mapped into and disguised as standard European HDSL formatted data.

Abstract: Method and apparatus for providing a regulated and current limited power source to support bidirectional telephone delivery circuitry and methods for a multiplicity of telephone subscriber lines to a downstream distribution terminal using only two preexisting transmission lines for carrying the regulated and current limited power along with a multiplicity of HDSL TDM communication channels.