Abstract: A system for recovering a clock signal from a data signal is described. The system uses an oscillator adapted to generate an oscillator output signal, a first detecting circuit for obtaining a coarse frequency-lock condition between the data signal and a recovered clock signal, a second detecting circuit for obtaining a phase-locked condition between the data signal and the recovered clock signal, a lock-detecting circuit responsive to the first detecting circuit for detecting an out-of-lock condition between the data signal and the recovered clock signal, and a control circuit responsive to the lock-detecting circuits and adapted to control the oscillator to generate an oscillator output signal on the basis of the first detecting circuit during an out-of-lock condition, and otherwise to generate the oscillator output signal on the basis of the second detecting circuit.

Abstract: A field reconfigurable muxponder for use in an optical transport system. The muxponder includes one or more tributary cards, where each tributary card is adapted to receive an optical data signal and conditions the optical data signal into an intermediate data signal constituted in accordance with a tributary interface format. In this way, the muxponder is able to aggregate optical data signals having different protocols and/or different data rates. The muxponder further includes a chassis that is adapted to receive a predefined number of tributary cards and outputs an optical system signal independently from the availability of the optical data signals from the tributary cards. The tributary cards and the chassis integrally form one line card.

Abstract: The present invention relates to an optical communications system performance monitoring technique which provides for detecting bit disparity within a data stream. The average power value for a data stream is ascertained by passing the data stream through a low pass filter. The data stream's average power value is then compared with a bit stream baseline power value for a one bit stream and a zero bit stream, the resulting deviation comprising a bit disparity value. An embodiment of this invention would incorporate the use of threshold alarms set for unacceptably high levels of bit disparity. The triggering of these threshold alarms could initiate the transmission of automated customer warnings such as a notification that performance cannot be guaranteed due to high bit disparity on the signal.

Abstract: In the reporting system disclosed herein, a speech recognizer is used to select sections of text from a report form stored in a computer and to insert recognized terms in the text thereby to generate a report text under voice control. A command interpreter, also responsive to spoken words, initiates creation of the report text and its subsequence storing, printing and transmission. The command processor is responsive to respective spoken commands to select a destination telephone number and to cause the report text to be sent to apparatus for converting report text to image data and for modulating an audio band signal with the image data for facsimile transmission over telephone lines.