Abstract: A method and corresponding apparatus for diagnosing problems on a time division multiple access (TDMA) optical distribution network (ODN) is provided. An example method may include: (i) measuring no-input signal power level on a communications path configured to carry upstream communications between multiple optical network terminals (ONTs) and an optical line terminal (OLT) in a passive optical network (PON) at a time no upstream communications are on the communications path from the ONTs to the OLT; (ii) comparing the measured no-input signal power level to a threshold; and (iii) generating a notification in an event the threshold is exceeded. Through the use of this method, faults in optical transmitters, such as bad solder joints, can be determined. Such faults may cause errors in parameters, such as ranging or normalization parameters, associated with communications. By determining the faults, the time required to resolve communications errors can be reduced.

Abstract: A method and corresponding apparatus are disclosed for controlling the phase of a second clock signal from (i) a first clock signal of different frequency and (ii) a synchronization signal. One example embodiment recovers a first clock signal from a bus carrying data and detects a synchronization signal. Both the first clock signal and the synchronization signal are provided to a clock generator, which then generates the second clock signal with a phased based on the first clock signal and the synchronization signal. The use of the example embodiment is a low cost way to easily control the phase of a second clock signal with minimal added components and/or additional signal processing.

Abstract: A method and corresponding apparatus for ranging an Optical Network Terminal (ONT) in a Passive Optical Network (PON) is provided. An example method may include: (i) transmitting a ranging request from an Optical Line Terminal (OLT) to an ONT in connection with a transport layer ranging window; (ii) monitoring for a ranging response from the ONT during at least one physical layer ranging window within the transport layer ranging window, the transport layer ranging window having a duration longer than the physical layer ranging window; and (iii) determining at least one metric associated with the ranging response for use in connection with upstream communications between the ONT and the OLT. The metric(s), used in connection with upstream communications, are accurately determined, and communications faults during normal operations are thus reduced.

Abstract: A method and corresponding apparatus for diagnosing problems on a time division multiple access (TDMA) optical distribution network (ODN) is provided. An example method may include: (i) measuring no-input signal power level on a communications path configured to carry upstream communications between multiple optical network terminals (ONTs) and an optical line terminal (OLT) in a passive optical network (PON) at a time no upstream communications are on the communications path from the ONTs to the OLT; (ii) comparing the measured no-input signal power level to a threshold; and (iii) generating a notification in an event the threshold is exceeded. Through the use of this method, faults in optical transmitters, such as bad solder joints, can be determined. Such faults may cause errors in parameters, such as ranging or normalization parameters, associated with communications. By determining the faults, the time required to resolve communications errors can be reduced.

Abstract: A method and apparatus for compressing, storing and transmitting measurement data correlative to machine status is disclosed in which the measurement data is continuously sensed, sampled and processed to extract significant spectral elements including magnitude and phase information from each successive period of the originally measured data and to store those spectral elements in a memory means from an initial period of significant spectral elements and each successive period of significant spectral elements which have changed since the previous period for developing a compressed data history correlative to a continuous history of the status of the machine being monitored and from which continuous signals can be regenerated and analyzed for any earlier historical time.