A system for providing DC power on local telephone lines, such as telephone lines in a building or office, for powering devices and circuitry associated with communications over those telephone lines, as well as other functions. Desired voltage and power levels are supplied over local telephone lines...http://www.google.de/patents/US7702095?utm_source=gb-gplus-sharePatent US7702095 - Method and system for providing DC power on local telephone lines
