Abstract: A method of detecting CPD in an HFC network is disclosed, where the network includes a return receiver, a cable plant, and a node. The node includes an optical receiver, optical transmitter, a diplexer having forward and return legs, a forward path defined between optical receiver and forward leg, and a return path defined between the optical transmitter and return leg. The optical receiver provides a forward signal to the cable plant and a portion of the forward signal leaks through the return leg and travels to the return receiver. The cable plant contains a CPD source which generates a CPD signal from the forward signal. The CPD signal travels to the return receiver.
Abstract: A method and apparatus is disclosed for enabling synchronous capture of forward and return signals at a remote PHY device for detecting CPD. The remote PHY device provides the forward signal to and receives the return signal from a coaxial cable plant. The return signal contains an actual CPD signal generated by an interaction between the forward signal and a CPD source in the cable plant. The forward signal propagates from the remote PHY device to the CPD source and the actual CPD signal propagates from the CPD source to the remote PHY device all within a round-trip interval.
Abstract: A method of detecting CPD in an HFC network that includes a remote PHY device (RPD) is disclosed. The RPD includes a transmitter, receiver, and diplexer having forward and return legs. The receiver receives a return signal from a cable plant via the return leg. The transmitter provides a forward signal to the cable plant via the forward leg. A portion of the forward signal leaks through the return leg and travels to the receiver. The return signal contains a CPD signal generated by the forward signal and a CPD source in the cable plant. The forward signal propagates from RPD to CPD source and CPD signal propagates from CPD source to RPD within a round-trip interval. The method comprises: (a) adjusting the capturing bandwidth of the receiver to include return and leaked forward signals; (b) operating receiver to capture return and leaked forward signals over a limited duration of at least the round-trip interval; and (c) detecting CPD signal by processing captured leaked forward and return signals.
Abstract: Synchronous capture of a forward signal and a related CPD signal at a remote PHY device (RPD) for detecting and locating CPD is disclosed. The RPD delivers the forward signal to a coaxial cable plant. The forward signal propagates from the RPD to a CPD source and the CPD signal propagates from the source to the RPD within a round-trip interval. The steps include: (a) capturing the forward signal from the RPD during the round-trip interval; (b) generating a reference signal, substantially simulating the CPD signal, from the forward signal; (c) supplying the reference signal to the RPD; (d) receiving the reference signal in the RPD via a return channel; and (e) capturing the CPD signal at the RPD in the return channel during the round-trip interval. Reference and actual CPD signals are processed as a combined return signal for detecting CPD.