System for jointly transmitting high-frequency and low-frequency digital signals over a fiber-optical carrier
Method for the additional transmission of information via a digital auxiliary channel, in an optical transmission system
Digital synchronizing circuit
Phase-locked clock regeneration circuit for digital transmission systems
System for the simultaneous operation of a plurality of terminal equipment at a network terminating unit of a broadband network Patent #: 4847833
ApplicationNo. 725544 filed on 07/03/1991
US Classes:398/185, Hybrid modulation341/73, To or from coded mark inversion370/522, Signaling (ancillary to main information)398/183, Having particular modulation714/798, Error detection for synchronization control714/811Forbidden combination or improper condition
ExaminersPrimary: Coles, Sr., Edward L.
Assistant: Pascal, L.
Attorney, Agent or Firm
Foreign Patent References
International ClassH04B 010/04
Foreign Application Priority Data1988-06-03 DE
AbstractIn a system wherein a main channel of data is transmitted between two stations by means of an optical waveguide, an additional optical channel may be transmitted. Bits of the additional optical channel are inserted into the main channel at a transcoder in the transmitting station in place of bits of the main channel at defined spacings, known to the transcoder of the receiving station, with a bit rate lower than that of the main channel. The inserted bits are removed from the optical main channel at the receiving station. The bits of the additional optical channel inserted into the main channel are double bits that are identical to a forbidden bit combination that results during the recoding of an electrical AMI code into an optical CMI code. In the receiving station, the double bits of the main channel replaced by the bits of the additional optical channel are recovered by using sequential logic and memory to apply the fixed rules of the electrical AMI code.
Field of SearchTo or from coded mark inversion