Abstract: An apparatus and method for detecting telephony signaling states, comprises an analog to digital converter and a microcomputer with associated firmware for controlling the operation of the microcomputer. The analog to digital converter digitizes incoming analog voltages containing telephony signaling state information and presents the digitized data samples for operation by the microcomputer. The microcomputer performs various digital filtering and analysis of the digital data samples in order to determine the signaling states represented by such digital data samples, and upon detection of the signaling states, outputs information indicative of such detected states. The present invention also incorporates use of such a detection circuit within line cards used to interface telephone subscriber lines with the central office terminal. The present invention further encompasses the methodology of performing such digital data sampling and analysis so as to determine telephony signaling states.

Abstract: Modular resonant cavities particularly for use in applications associated with high frequency electromagnetic energy each comprise a shell defining an aperture formed therethrough, and either end plates and/or divider closure plates, each having stepped-down regions for interfitting at perimeter ends of adjacent shells so as to form a resonant cavity. The modular resonant cavities include support rods passing through the corner regions of each closure plate. Fastening means at each end of the rods mechanically secure the modular resonant cavities together.

Abstract: In order to protect electrical and fiber optic cables in a central telephone office terminal equipment frame, the cables are controlled and managed so as to be releasably retained in a service loop within a fiber management panel. The releasable retention is performed by a stretched extension spring selected, dimensioned and stretched in such a manner with respect to the diameter of the cables that each cable can be gently but firmly retained when pressed into the gap between adjacent coils. The retention spring permits emergency release of the cable in the event of mishandling of the equipment by service personnel.

Abstract: A parallel time slot interchanger, particularly for use in telecommunication switching, comprises a plurality of switch groups, with each switch group containing a second plurality of channels. The parallel time slot interchanger incroporated a matrix-type architecture, with each module of the matrix comprising a switch block which in turn incorporates a switch memory, connect memory and associated control circuitry. The connect memory of each switch block is controlled by the control circuitry of that block. The data stored in the connect memory contains switch memory address information for reading channel data stored within the switch memory of the same switch block so as to be able to perform a time slot switching function during any given time slot of the parallel time slot interchanger. Each switch block is uniquely identified within its corresponding switch group so that only one switch memory address location is read and output during any time slot for each switch group.

Abstract: A fiber optic switch is formed using cylindrical or biconic fibers optic connector components for axially aligning pairs of fibers to be switched. The ferrules of the connector are rotatably mounted within an alignment sleeve, such that a pair of fibers in a first ferrule may be rotated relative to a pair of fibers mounted in a second ferrule to effect a bypass switch operation. Various forms of switch actuators, including rotary and linear actuators, are disclosed, along with fail-safe arrangements.

Abstract: In pulse code modulation communications systems where network links, using A, AB and ABCD signaling systems having different sized bit patterns and signaling rates for signaling operations, are interfaced, apparatus is provided to control the mapping of signaling patterns at signaling rate conversion boundaries.

Abstract: A mounting device for mechanically retaining separable transfomer core portions together and attaching the transformer assembly to a printed circuit board utilizing a flat clip body and a vertically aligned spring unit to minimize the transformer assembly height and four mounting legs to allow easy installation and removal.

Abstract: By providing two comparators, each of which have a reference voltage level source connected to one input, and separate voltage level producing/enhancing circuits connected to the contacts of a relay, so that each alternate switch configuration produces a different voltage level at the two comparators, a unique relay switch detection circuit is attained. Preferably, three separate voltage level producing/enhancing circuits are employed, with one circuit connected between the relay output and the two comparators, while the other two circuits are connected to the primary or the secondary relay contacts. Futhermore, the voltage level resulting from each particular switch configuration is pre-set relative to the reference voltage level source imputs to assure that the two comparators produce different combined outputs for each alternate switched condition.

Abstract: A tool is provided for the purpose of allowing access to optical fibers held within a buffer tube. The buffer tube is held in a closed channel formed by the engagement of a clamp against a main body. A blade is inserted from the main body into the buffer tube so as to define a chord across the cross section of the buffer tube. The tool is drawn along the buffer tube so as to remove a portion of its protective covering threby allowing access to the optical fibers held therein.

Abstract: An optical fiber cable having a predetermined length includes a plurality of optical fibers, each fiber having first and second ends. The first ends of the fibers are located coincidental with a first end of the optical fiber cable. The optical fibers are provided with differing lengths so that the second ends of the optical fibers are disposed at different locations along the length of the optical fiber cable. Indicia are provided on the cable to indicate the locations of the second ends of the fibers.

Abstract: A low speed channel bypass apparatus is described for reprovisioning the time slot multiplexer associated with an add/drop multiplexer so as to insure that particular low speed channel(s) within a high speed channel are passed through the add/drop multiplexer via the time slot multiplexer when the operation of an associated network controller is determined to be faulty. The low speed channel bypass apparatus is particularly directed for use with a high speed channel conforming to the synchronous optical network communication standard (SONET). A watchdog timer is used to monitor the performance of the network controller. The watchdog timer when timed out not only prevents further operation of the network controller, but instructs an associated reprovisioning apparatus to instruct the time slot multiplexer to connect through selected channel(s) from the east high speed interface to the west high speed interface.

Abstract: In a telephone system, a composite detection circuit and method for use in mechanized loop testing to detect both AC ringing and DC coin control voltage at a test access unit. An equalization circuit distinguishes between the two voltages and selectively amplifies the DC components of the voltages, thus amplifying the positive DC coin control voltages out of the detection range of the negative AC ringing voltages and vice versa. Two distinct outputs indicate either a positive or negative voltage detected. Two identical circuits are used, one on the ring line and one on the tip line, to detect positive and negative ringing and coin control voltages.

Abstract: By providing control logic for initiating a predetermined test sequence depending upon the known state of a relay, a unique testing circuit is attained whereby the relay drivers connected to the opposed sides of the relay coil are fully evaluated without causing the relay to be activated. In the preferred embodiment, the relay comprises a latching-type relay and the relay drivers comprise separate high-power CMOS devices. In this configuration, the control logic separately activates each transistor of each of the high-power CMOS devices without causing the relay to be switched between its two alternate configurations. Furthermore, the control logic originally sets the latching-type relay into one of its two configurations and then shuts off the power until activated for initiating the test sequence. In addition, the control logic is employed to check each transistor during the test sequence and assure its operation.

Abstract: An optical fiber cable contains a central strength member surrounded by a plurality of fiber-carrying guides traversing the length of the cable along reversing helical paths. A plurality of strength members are provided in lieu of selected symmetrically spaced guides. The strength members provide axial and torsional stability due to their reversing helical path. Periodic bandmarks are provided on each fiber for identification. An excessive length of fiber is provided in each guide to minimize fiber stress.

Abstract: An add/drop interface is connected in series with a data bus and is constructed for receiving an add/drop module. The add/drop interface includes a data selection multiplexer which receives through data from the data bus and add/drop from the module and selects the proper output data in response to a signal received from a controller in said interface. The controller provides a signal to drive the data selection multiplexer to select the add/drop data only after all transient signals resulting from module connection have dissipated. The controller also provides error checking so that the through data is selected if errors are detected. Timing circuitry in the interface maintains the correct phase relationship between through data and add/drop data.

Abstract: The present invention is directed toward a fiber optic cable comprising a central core which has one or more helical channels in its periphery. One or more tubes containing a dielectric water-blocking compound and one or more optical fibers are positioned in the channels. The fibers are randomly arranged within the tubes in such a way that tensile stresses on the cable are not transmitted to them, thus providing an elongation window. Finally, the assembly formed by the core and the tube or tubes is wrapped with a serving of metal wires. In one embodiment, the core and tubes may be wrapped with a tape layer before the outer metal wires are applied. Any interstices among the core, the tube or tubes, and tape may also be filled with another dielectric water-blocking compound.

Abstract: A light source or detector equipped with an optically transmissive window is coupled to a juxtaposed collimating lens for directing light onto a first side of a dichroic filter which passes or blocks a selected wavelength of light. A second lens in juxtaposition with a second side of the dichroic filter focuses light either passed or reflected by the filter onto an optical fiber for transmission or reception of optical signals. A second optical fiber is connected to the second lens and to a third lens for which conveys light between the second optical fiber and a dichroic filter for passing a different wavelength of light and reflecting the selected wavelength, the filter being in juxtaposition with a window of an optical detector. All components are embedded in a molded enclosure for protecting the optical elements and optical fibers from environmental conditions.

Abstract: A dielectric notch filter for attenuating frequencies of relatively narrow bandwidth in comparison to the center frequency of operation, and particularly for attenuating such narrow bandwidths in the ultra-high frequency electromagnetic spectrum. The dielectric notch filter comprises a plurality of dielectric notch resonators coupled to a transmission line at slightly less than the quarter wavelength of the center frequency of the attenuation frequency bandwidth so as to minimize interaction between the individual dielectric notch resonators. Each dielectric notch resonator comprises a dielectric resonator, an associated housing and a coupling reactance element which in turn comprises an inductive wire and a variable capacitor so as to null the reactive component of the dielectric resonator, thereby resulting in a highly attenuated resonant frequency having little imaginary component about said center frequency.

Abstract: Real-time conversion between two different A/B signal coding schemes based on the DS1 time division multiplex format is achieved by time sharing a programmable state machine. The time sharing is accomplished synchronously with the DS1 superframe such that each of the 24 DS1 channels have signalling translated once every superframe. Programmability of the state machine is facilitated by the use of an EPROM. A RAM is used for real-time storage of signal states, machine states and processor provisioning for each channel, thereby facilitating time sharing of the state machines. Flexibility is provided through the unique use of an EPROM, which can be modified to directly change the signalling translation response depending on the type of telephony service being provided and the coding scheme used for the signalling. Processor provisioning of the RAM selects a service type translation for each of the 24 DS1 channels.

Abstract: A double-clad single mode optical fiber with a depressed inner cladding exhibits increased resistance to attenuation increases resulting from small radius bends and lower attenuation sensitivity to temperature changes when the mode field diameter is less than 7 um and the ratio of the radius of the inner cladding to the radius of the core is at least 6.5 to one.