Abstract: An enclosure containing heat generating electrical components is provided with exterior heat fins and is enclosed within a perforated cover. The heat fins are generally planar and parallel to define vertical channels between adjacent pairs of fins. The fins are formed with a plurality of aligned notches to define a plurality of horizontal channels. The perforations in the cover are arrayed along a plurality of horizontal lines, with at least one of the horizontal lines overlying each of the horizontal channels.

Abstract: In an RF filter having an input terminal, an output terminal, a plurality of resonator elements, and a plurality of coupling reactances for coupling one resonator element to another resonator element, for coupling the input terminal to a resonator element, and for coupling the output terminal to a resonator element, techniques are disclosed for providing an RF filter having an electronically tunable center frequency and an electronically tunable bandwidth. According to a specific embodiment disclosed herein, a first shunt reactance is provided from the input terminal to ground, and a second shunt reactance is provided from the output terminal to ground. The values of the coupling reactances remain constant, while the values of the resonator elements, the first shunt reactance, and the second shunt reactance are tuned to provide a specified filter bandwidth and/or a specified center frequency.

Abstract: The presence of a supervisory audio tone signal (SAT), superimposed on a voice/data signal transmitted in a cellular telephone system, is carried out by first deleting the voice/data signal, leaving only the SAT signal. Thereafter, the SAT signal power and noise power are determined. During intervals when the SAT signal rises and falls, the SAT noise power and signal power move in opposite directions when the radio carrier turns on and off, respectively. By comparing the SAT noise power to the SAT signal power, a fast, accurate determination can be made as to whether the SAT signal is present. Moreover, the ratio of the SAT signal power to SAT noise power provides a good estimate of the quality of the channel in the cellular telephone system. By repeatedly computing the SAT signal power to noise power ratio, a base station (48) in the cellular telephone system can decide when to hand off, and to which other base station such hand-off should be made.

Abstract: In the network of the invention, telephony and other narrow band services are provided using twisted pairs via existing fiber-in-the-loop (FITL) technology while the analog video and digital broadcast video are carried over a single coaxial cable to the customer premise. All customer subscriber lines are moved out of the central office and are distributed in the outside distribution plant via FITL technology. Data and digital video from the central office are distributed to a large number of field located optical network units (ONU) as ATM signals over optical fibers. The narrowband signals are converted to a SONET virtual tributary group and are combined with the digital video signals for delivery to the home.

Abstract: A low distortion amplifier circuit employing a main amplifier and a correction amplifier in a feed-forward loop, is particularly adapted for amplifying multi-tone signals. The main amplifier produces fundamental frequency power along with undesirable distortion products. The correction amplifier provides correction signals at the distortion product frequencies to cancel the distortion products of the main amplifier. In addition, the correction amplifier produces fundamental frequency power which is combined with the fundamental frequency power of the main amplifier, thereby increasing the amplifier circuit output power.

Abstract: An isolation circuit for use in a power plant having a first power supply that powers a first load and a second power supply that powers a second load. The first and second power supplies are cross-couplable via a first and second auxiliary path to allow the first power supply to power the second load and the second power supply to power the first load. The first power supply is subject to a reverse current by way of the first auxiliary path. The isolation circuit includes a first switch, located in the first auxiliary path, that substantially reduces the reverse current flowing into the first power supply thereby enhancing an isolation of the first power supply. A controller is, also, provided that monitors the first switch thereby enhancing a reliability of the power plant.

Abstract: A printed circuit (PC) board-mountable ferrite electromagnetic interference (EMI) filter (702, 1003, 1003") for PC conductors (701, 1001, 1002) of a printed circuit (PC) board (700, 1000) that accommodates large numbers of PC conductors, and is cost-effective. One embodiment of the EMI filter is used with a PC board (700) that routes PC conductors (701) in a step-function (i.e., a "U"-shaped) pattern. The EMI filter comprises a ferrite body (702) that defines two parallel passageways (708, 709), i.e., has a figure-8 shape in cross section. The portion (710) of the PC board that defines the PC conductor portions extending in the one direction lies in one passageway, whereas the portion (711) of the PC board that defines the PC conductor portions extending in the other direction lies in the other passageway. A different embodiment of the EMI filter is used with a PC board (1000) that routes sets (1001, 1002) of PC conductors in a cross-hatch (i.e.

Abstract: A sketching system sketches first notes to be transmitted over a telephone line receives second notes from another sketching system. The sketching system includes a signal de-combiner device, receiving the second notes from the another sketching system and voice data as a combined signal via the telephone line and de-combining the combined signal into the second notes and the voice data. In addition, the sketching system includes a sketching unit connected to the signal de-combiner. The sketching unit includes a note displaying device displaying the first and second notes, a note generating device generating the first notes, and a processor connected to the note displaying and generating devices and to the signal de-combiner, receiving the first notes from the note generating device, receiving the second notes to the note displaying device.

Abstract: A computer system and method provide a CAD tool by which a mask for an application specific optical integrated circuit, chip, or wafer may be generated both easily and quickly. The method involves the step of receiving the design for an optical circuit with the circuit design including at least one optical component. Each optical component in the optical circuit is defined by one or more geometric shapes, such as a trapezoid, rectangle, or an arcuate polygon. The method further includes the step of retrieving parameters which define the manufacturing standard by which the optical circuit will be fabricated as well as parameters which define the optical components in the optical circuit. Based on the parameters and the geometric shapes, a plot is generated which forms a mask layout for the optical circuit. The mask layout can then be viewed by a graphical editor whereby a designer can receive visual confirmation that the mask layout accurately portrays the desired optical circuit, chip, or wafer.

Abstract: Cracking in thin sheets of sol-gel-produced material is avoided by use of a support liquid during gelation and drying. Silica glass, as well as other glass and ceramic bodies, is contemplated.

Abstract: An apparatus for providing detent-like tactile feedback to a user, comprising a shell, a rolling member rotatably provided within the shell, a motion sensing mechanism for determining displacement of the rolling member when the rolling member is rotated, at least one actuator situated within the shell and at least one brake member provided with respect to the at least one actuator, the at least one actuator retracting and extending the at least one brake member to selectively influence the rotation of the rolling member based on feedback from the embodying system.

Abstract: A method of making a mold for a given object includes forming a wire stack of elongated wire elements and aligning first ends of the wire elements to define a first end surface of the stack, displacing selected wire elements with respect to the first end surface of the stack by determined amounts in the longitudinal direction of the elements according to a shape of the object to be molded, and then fixing the wire elements of the stack from movement relative to one another after the wire element displacing step. A mold surface for the given object is thus defined according to the first end surface of the wire stack.

Abstract: A time-division-multiplexed fixed wireless loop system and methods therefor are disclosed. The system comprises a plurality of cells each having a base station and a plurality of terminals. The base station includes a steerable and adjustable multibeam antenna for communicating with each of the terminals, which have fixed antennas. A cell controller associated with each base station allocates communication time slots so as to minimize mutual interference between base station/terminal links sharing the same time slot. Slot assignment is based on regional, periodically updated interference measurements that are stored in data bases.

Abstract: 216-type screws and KS-type screws are two types of fastening devices typically used to restrict access to the chambers of building entrance protector (BEP) enclosures used in telecommunications applications. Access to such chambers is limited to those users who have special tools designed for one or the other type of screw. The present invention is a screw that can be actuated using either the special tools designed for 216-type screws or the special tools designed for KS-type screws. In particular, screws of the present invention have a hexagon-shaped outer surface like a 216-type screw and a hexagon shaped recess with a cylindrical upstanding post in the middle of the recess like a KS-type screw.

Abstract: A finger tracking circuit for a rake receiver, a method of tracking a carrier signal and a wireless infrastructure. The finger tracking circuit includes: (1) a timing error subcircuit that determines a timing error in a current power control group ("PCG") of a carrier signal to be tracked and (2) a feedback subcircuit that applies a gain signal that is a function of a data rate of the carrier signal and a signal-to-noise ratio ("SNR") to the timing error subcircuit, a convergence rate of the finger tracking circuit therefore depending on the data rate of the carrier signal.

Abstract: A scheduling mechanism for satisfying specified Quality of Service guarantees for each VC of an end-point host in an ATM network and for satisfying low latency requirements of certain VCs while maintaining high throughput. The scheduling mechanism includes at least one time slot ring, a VC table and at least two pending queues. The time slot ring is an array of time slots grouped into clusters. Each slot contains a pointer which contains the virtual channel identifier to be serviced. The VC table is an array of all the VC descriptors. The pending queues are used for queuing a new VC and when the scheduler is unable to find a time slot for a VC it is queued in the pending queue. One pending queue is restricted to VCs requiring low latency and thus need to be serviced prior to servicing other VCs not sharing the same low latency requirements. A second pending queue is used for VCs with a less critical latency requirement. The ring contains cluster pointers which point to the first VC to be serviced.

Abstract: The system of the present invention allows a customer to access a company computer system via a data network and to request contact with a customer service representative. The company computer system automatically selects a customer service center and a customer service representative in accordance with a set of selection criteria, including customer preferences. A monitor, also connected to the company computer system via the data network, may choose to accept or to change the selections made by the company computer system. Once a customer service representative has been selected, the company computer system causes a telecommunication control device to connect the customer, the selected customer service representative, and the monitor via a voice network. If a monitor is not available, the company computer system causes the telecommunication control device to connect the customer and the selected customer service representative, and then records the communication therebetween for future review by a monitor.

Abstract: Various DC/DC converter topologies having improved electromagnetic interference (EMI) characteristics and methods of providing dual DC outputs with such converters. One embodiment of one DC/DC converter having dual, EMI-quiet outputs includes: (1) a first subcircuit, having a series-coupled first switch, first inductor and first capacitor and an output across the first capacitor, coupled between first and second DC input rails, (2) a second subcircuit, having a second switch, second inductor and second capacitor and an output across the second capacitor, coupled between the first and second DC input rails in anti-parallel with the first subcircuit, (3) a first diode coupling a node between the first switch and the first inductor and a node between the second inductor and the second capacitor and (4) a second diode coupling a node between the first inductor and the first capacitor and a second node between the second switch and the second inductor.

Abstract: A multicarrier communication system for wireless transmission of blocks of data having a plurality of digital data symbols in each block. The communication system includes a device for distributing the digital data symbols in each block over a plurality of clusters, each of the clusters receiving one or more digital data symbols. The digital data symbols are encoded in each of the cluster; and modulated in each cluster to produce a signal capable of being transmitted over the sub-channels associated with each cluster. A transmitter thereafter transmits the modulated signal over the sub-channels. By distributing the modulated signal over a plurality of clusters, overall peak-to-average power (PAP) ratio is reduced during transmission and transmitter diversity is improved.

Abstract: In a power converter having a power train that includes a power switch and a rectifier for conducting forward currents from the power switch, a circuit for, and method of, reducing switching losses associated with the power train. The circuit includes: (1) an auxiliary switch and an inductor coupled to the power train that reduce a switching loss associated with the power switch and (2) an impedance element series-coupled to the rectifier that reduces a change in current through the rectifier thereby decreasing a reverse recovery current flowing therethrough.