Abstract: A method for fabricating an optical attenuator from first and second optical fibers includes placing the fibers in closely spaced overlapped relation to define an overlapped portion of the fibers. Energy is initially applied to the overlapped portion to at least partially fuse the first and second fibers at the overlapped portion.

Abstract: A card is provided for insertion in a telecommunications chassis. The card includes two sets of ports each having tip and ring contacts. The normal springs of the first set are electrically connected to normal springs of the second set.

Abstract: A jack module including a switching jack subassembly and monitor jack assembly includes a printed circuit board between the subassemblies. The subassemblies and circuit board are commonly housed. The printed circuit board contains monitor circuitry. The monitor circuitry is an inductive monitor with redundant windings.

Abstract: A fiber optic connector polishing fixture for polishing optical fibers which are to be connected with other optical fibers includes synthetic ruby balls symmetrically aligned on an aluminum substrate which is configured to permit a ferrule and its outer housing to be inserted for polishing. The ruby balls define a polishing plane axially spaced from the substrate for polishing an optical fiber which is longitudinally disposed within the ferrule. The ruby balls and ferrule are moved along an abrasive material until the ferrule and optical fiber are suitably polished.

Abstract: A telecommunications system includes an added bit signalling method and apparatus for conveying signalling information between a head end and multiple remote ends connected over a passive distribution network. In accordance with the present invention, an added bit having an identifiable data sequence patterned thereon is appended to each channel within a succession of frames. In the system, the modified channels are broken up, routed reconstructed into a modified framing format and transmitted to their respective destination remote units. Because individual channels within a given frame are broken up and reconstructed into modified frames with channels from other frames, the framing information formerly identified by the framing bit is lost. The present invention therefore appends an added-bit sequence to each channel such that each channel sample carries its own multiframe and alignment information.

Abstract: When processing video television information the low frequency band is inherently of primary interest due to the natural averaging properties of the human eye, combined with the limited frequency response of video display elements such as phosphorus and liquid crystal displays. Noise is generated and observed in the low frequency region of digitized analog video signals due to nonlinearities inherent in the digitization process. This invention reduces the noise measured in the low frequency region by shifting the noise upband and out of the frequencies of interest by adding a dither signal to the analog input signal and employing a 2X decimation digital filter to remove the unwanted dither and spurious intermodulation signals. The disclosed invention allows for a simple and inexpensive means for removal of the dither signal without having to resort to complex dither subtraction techniques employed in the prior art.

Abstract: A universal pattern generator generates a digital signal pattern. The generator includes a user programmable device for specifying a repeatable digital signal pattern. The programmable device allows for the selection of a framing structure having a number of channels. The programmable device also has input means for inputting data into the channels of the framing structure. A data set representing the repeatable digital signal pattern is generated. The data set is held in memory. A transmitter responsive to the data set held in memory repeatably transmits the repeatable digital signal pattern represented by said data set.

Abstract: A system monitors the performance of a communications network and isolates the location of equipment failures therein through analysis of performance error data. The system passively monitors the performance of the network, operating in the background during normal data and/or voice transmission. The head end generates and inserts multiple error codes, one for each remote unit, into the downstream traffic path. Each remote unit extracts and decodes its respective error code to determine whether a downstream error occurred. Each remote unit then calculates a new error code based on the result of the downstream decode and the respective upstream data message. The head end receives the upstream error codes from all the remote units, decodes them, and accumulates the error data from all remote units over a period of time. An error distribution is generated, and an analysis is performed thereon to isolate the location of error causing equipment failures.

Abstract: A fiber distribution frame includes a fixture having a plurality of modules mounted side-by-side within said fixture with each of the modules being individually mounted in a line of travel. Each of the modules can be locked in any one of a plurality of discrete positions within the line of travel. Each of the modules contains a plurality of adapters for receiving and retaining fiber optic connectors. Further, the fixture may be tilted downwardly to provide access to the rear of the fixture.

Abstract: A miniature coax jack module includes a grounded conductive housing with coax conductors disposed of within the housing. A dielectric insert maintains the conductors in electrically spaced relation to the housing. The housing has internal surfaces surrounding the conductors to provide coax shielding to the conductors.

Abstract: A rotary fiber optic switch switches a first optical fiber among a plurality of second optical fibers. The switch is calibrated with a control mechanism such that movement of the rotated fiber to a prescribed position achieves a maximum power transmission between the first fibers and an opposing one of said plurality.

Abstract: A master/slave communication and control system includes a master controller and a plurality of slave subsystems, the master controller connected with the slave subsystems through first and second independent serial data buses, one of the data buses providing a working data bus, the other data bus providing a standby data bus. The master controller generates a A/B select signal applied to each of the slave subsystems to select which of the A or B data buses the slave .subsystems will use to communicate with the master controller. Each of those slave subsystems generates an independent request for communication signal, carried on an input request line to the master controller. A plurality of kill signals are generated by the master controller and applied over independent kill lines to each of the slave subsystems, whereby the master controller may send the kill signal to any one of the slave subsystems.

Abstract: A ringing generator includes a binary signal source generating a waveform with eight degrees of freedom controlled to suppress or cancel certain harmonics to produce a binary low frequency signal substantially free of low frequency components other than the desired ringing frequency. The binary signal is amplified and filtered to remove unwanted frequency components above a certain threshold to produce a substantially sinusoidal ringing signal.

Abstract: A fiber optic connector module includes a beam splitter for directing 10 percent of a fiber optic signal to a monitor connector. The input of the beam splitter is passed through a variable attenuator. By monitoring at the monitor connector, the variable attenuator can be adjusted utilizing the known split ratio of the beam splitter to achieve a desired dynamic range of the optical signal leaving the module.

Abstract: An optical switch is disclosed for a system including signals carried over a plurality of optical fibers. The switch comprises a first and second plurality of optical fibers with each of the fibers terminating at a terminal end. A first switch body is provided for holding fibers of the first plurality in a closely packed array with terminal ends disposed circumferentially about a common first axis. A second switch body is provided for holding fibers of the second plurality in a second array. The first and second arrays are selected for at least a portion of terminal ends of the fibers of the first plurality to be optically coupled with terminal ends of at least one of the fibers of the second plurality when the first array is angularly displaced about the first axis in any one of a plurality of angularly displaced positions.

Abstract: A connector for terminating coax cables includes a center pin mounted in a dielectric support. The support has a resilient locking arm which snaps into a recess of the center pin to prevent relative axial movement of the pin and the support.

Abstract: An optical fiber distribution frame is disclosed which includes a plurality of modular cabinets. The plurality of cabinets includes a connector cabinet having a front panel with sleeve adaptors for mounting a plurality of connector sleeves on said panel at an angle to said panel.