Patent ID: 6775299
Filing Date: 2004-08-10
Classification: H04Q

Abstract:
A bidirectional telephone delivery system for supporting a multiplicity of telephone 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 said downstream distribution terminal, comprising:two transmission line pairs extending between said upstream distribution terminal and said downstream terminal; said upstream distribution terminal comprising; power circuitry for generating a source of regulated and current limited DC power and having a power output terminal and a return terminal; upstream formatting circuitry for mapping a multiplicity of PCM formatted data packets into a standard communication format different than said PCM format, for transmission on two transmission line pairs, wherein said standard format which is different than PCM format is standard European HDSL formats ETSI ETR-152 format, said mapping into said ETSI ETR-152 format comprising the providing of Cycle Redundancy Check (CRC) information in Channel Unit Data Link (CUDL) slots so that a CRC verification may occur independent of successive ETSI frames being received; an upstream pair of isolation transformers, each of said pair having an upstream coil connected to said formatting circuitry and each having a downstream coil connected across one of said transmission line pairs, each of said downstream coils of said pair of transformers further being connected one each to said power output terminal and said return terminal of said power circuitry; said downstream distribution terminal comprising:DC power distribution circuitry for receiving power from said upstream power circuitry on said pair of transmission line pairs for providing a DC power source in said downstream distribution terminal; and downstream formatting circuitry for receiving said PCM data packet formatted in said different format and reformatting in standard PCM format and a downstream pair of isolation transformers, each having downstream coils connected to said downstream formatting circuitry and upstream coils connected across one of said transmission line pairs.