Abstract: An apparatus is disclosed for providing access to a plurality of telecommunications lines and for providing continuous monitoring access to the telecommunications signals on the lines. The apparatus includes a frame which carries a plurality of normally closed contacts and monitor ports and corresponding monitor circuits for providing continuous access to the telecommunications lines. The telecommunications lines are terminated on the normally closed contacts. A plurality of modules may be releasably attached to the frame with electrical circuit elements on the modules breaking the normally closed contacts to create a new signal path through the module. The modules need only be attached to the frame when direct access to the signal is desired.

Abstract: A combiner-amplifier is provided which has first current feedback amplifier which amplifies a first received signal by a predetermined gain value. A second current feedback amplifier amplifies a second received signal by the predetermined gain value. A combiner is operatively coupled to the first and the second current feedback amplifiers to combine the amplified first received signal with the second received signal together to generate a combined signal which is attenuated by the predetermined gain value such that the combined signal has approximately a unity gain over the first and the second received signals within a bandwidth of at least 45 megahertz.

Abstract: A method of communicating a plurality of two-way inbound/outbound cellular telephone transmissions between a base station and a physically remote cell using a set of channels. At the base station, a plurality of outbound telephone transmissions, received from a network, are analog modulated onto respective ones of RF analog outbound channel carriers. The modulated analog channel carriers are combined to form a single RF analog outbound signal representing all of the outbound telephone transmissions in the set of channels. The analog outbound combined signal is subsequently digitized into a single stream of outbound digital samples and transmitted to the remote cell. At the remote cell, the stream of digital samples is converted back to the RF analog outbound combined signal and broadcasted directly to mobile units in the cell. Further, the remote cell receives a plurality of simultaneous inbound telephone transmissions from the mobile units as an RF analog inbound combined signal.

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 microcellular communications network has multiple base-station units all at a common location. Each unit has all-digital transmitters and receivers coupled by fiber optic cable to individual remote locations each having power amplifiers and diversity receivers which convert the RF signals directly between analog RF and digital signals in the RF band at the remote locations. The system includes filtering, framing, and multiplexing of multiple channels. The system also provides passive handoff and passive switching. The system may be deployed in two different stages.

Abstract: A microcellular communications network includes a plurality of base station units and corresponding antenna units. Each includes either conventional transmitters and receivers or all digital transmitter and receiver equipment, and interface circuitry to a mobile telecommunications switching office. The microcell traffic output is applied to a frame generator/multiplexer. The output of the frame generator/multiplexer is applied to a digitally modulated laser and conveyed by fiber to a remote antenna unit, which demultiplexes the microcell traffic signal, applies it to a digital-to-analog converter, and applies it to a power amplifier and a main antenna. The received signals are filtered, digitized, multiplexed together and transmitted over the optical fiber back to the base station. The strongest signal is selected for use. Deployment of an all digital microcellular communications system occurs in two stages.

Abstract: The invention relates to a resonator shell construction, comprising at least two metallic shell modules (41-44) connected to each other to form a modular shell construction, each module enclosing at least one resonator cavity (42-52). The modules comprise wall portions (41a-41c, 42a-42c, 43a-43c, 44a-44c) projecting from the modules, said wall portions being connected to one or more modules, whereby one or more new resonator cavities (61-68) are formed between the modules.

Abstract: A microcellular communications network includes a plurality of base station units and corresponding antenna units. The base station units are housed in a common location. Each includes either conventional transmitters and receivers or all digital transmitter and receiver equipment, and interface circuitry to a mobile telecommunications switching office. The microcell traffic output is applied to a frame generator/multiplexer. The output of the frame generator/multiplexer is applied to a digitally modulated laser. The laser output is conveyed by fiber to a remote antenna unit, which demultiplexes the microcell traffic signal and applies it to a digital-to-analog converter. The output of the digital-to-analog converter is applied to a power amplifier, which in turn is connected to a main antenna. RF signals from the mobile units are received at both a main and a diversity antenna. The received signals are filtered, digitized, multiplexed together and transmitted over the optical fiber back to the base station.

Abstract: A passive handoff cellular communication system includes a cell divided into a plurality of zones. A base station is connected by transmission apparatus to a plurality of antenna units. The base station includes analog RF signal generation circuitry for generating a plurality of RF signals on different channels and a first switch responsive to a first control signal for switching and combining the RF signals to form a composite RF signal for each zone. Analog-to-digital conversion circuitry converts the composite signal for each zone to a digitized stream of samples and applies the samples to the transmission apparatus for transmission to each corresponding antenna unit.

Abstract: A non-invasive testing system for video signals includes a jack having a monitor conductor connected across an amplification circuit to a central conductor. The amplification circuit amplifies the power of a signal drawn off of the central conductor such that the power level at the monitor conductor is substantially equal to the power level on the central conductor. When it is desired to test a power level of a signal being produced by a video source, test equipment is connected to the monitor conductor to permit non-invasive testing of the signal.

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.