Abstract: A signal processor for, e.g., a telephonic communication system interconnecting a near location and at least one far location includes an echo canceller for suppressing the re-transmission of received signals. The operation of the echo canceller is controlled according to whether the near location is transmitting or receiving, and whether the far location is transmitting or receiving. The signal processor includes means for detecting doubletalk, and for controlling the echo canceller in response to the detection of doubletalk, such that doubletalk is permitted. In one method of operation, a delay is applied to the inputs to the echo canceller from the near and far ends, such that each of these signals is used for determining the operating state of the echo canceller before being used to operate an adaptive filter of the echo canceller. In another method of operation, doubletalk detection is carried out, in part, by evaluating the performance of an auxiliary adaptive filter.

Abstract: A hinged mounting bracket and attachable ground bar used in conjunction with a telephone wire termination block. The mounting bracket is adapted to accept modular connectors in order to form any size connecting block. The hinged bracket consists of two pieces, a bracket base and a front flap which receives the modular connectors. In a preferred embodiment, the front flap is coupled to the base by a hinge which enables the bracket to rotate open so that rear terminals of the modular connectors may be easily accessed. The ground bar is attachable to the front or rear of the mounting bracket in order to provide a ground for gas tube circuit protectors that may be inserted into the modular connectors. The ability to secure the ground bar to the mounting bracket in a variety of orientations provides additional flexibility for all types of wiring schemes. In a preferred embodiment of the invention, the ground bar couples to support posts on the mounting bracket utilizing a force fit insertion.

Abstract: Compression of a plurality of signal samples y(t.sub.0),y(t.sub.1),y(t.sub.2) . . . y(t.sub.z) may be accomplished by performing a first linear regression to obtain a curve fitted thereto which is represented by a polynomial having a first set of coefficients (a.sub.0,a.sub.1,a.sub.2,a.sub.3 . . . a.sub.n) which is stored in memory (18) or transmitted by a transmitter (20). The error between each of the actual signal samples (y(t.sub.0),y(t.sub.1),y(t.sub.2) . . . y(t.sub.z) and the value approximated by the curve fitted to the values is computed and then thresholded. A second regression analysis is then performed to fit a curve, having a second set of coefficients (b.sub.0,b.sub.1,b.sub.2,b.sub.3 . . . b.sub.q) to the thresholded error values. The second set of coefficients is also stored or transmitted and used, in conjunction with the first set of coefficients, to closely approximate the original set of signal samples.

Abstract: An arrangement (FIG. 1) that allows banks (15, 25) of up to eight duplicated active devices (30-37, 40-47) to be connected to a SCSI bus (14) and to share SCSI device IDs, and also allows multiple hosts (10, 20) to share the SCSI bus and the connected active devices. Tri-state buffers (200) act as gates (13, 23, 38, 48) to interface host adapters (12, 24) of a plurality of hosts, and active devices of a plurality of device banks, to the SCSI bus. The gate of only one host adapter and the gates of only one bank of devices are enabled at any one time. Only the devices of the enabled bank can receive and respond to addresses from the SCSI bus, while the devices of the other banks are prevented from receiving and responding to addresses from the SCSI bus. Each host has a tri-state buffer acting as bank selector (16, 26) for selecting one of the device banks, by enabling the gates of the devices of the selected bank through a bank select bus (50). Only one host's bank selector is enabled at any one time.

Abstract: In accordance with the invention, a new type of monolithic optical waveguide filter comprises a chain of optical couplers of different effective lengths linked by differential delays of different lengths. The transfer of the chain of couplers and delays is the sum of contributions from all possible optical paths, each contribution forming a term in a Fourier series whose sum forms the optical output. A desired frequency response is obtained by optimizing the lengths of the couplers and the delay paths so that the Fourier series best approximates the desired response. The filter is advantageously optimized so that it is insensitive to uncontrolled fabrication errors and is short in length. The wavelength dependence of practical waveguide properties is advantageously incorporated in the optimization. Consequently, the filter is highly manufacturable by mass production. Such filters have been shown to meet the requirements for separating the 1.3 and 1.551 .mu.

Abstract: A method and structure for automatically calibrating various paths within multi-channel analog integrated circuits is disclose. The invention calls for digital signal processing circuitry to correct for absolute gain differences in the multiple channels. A first reference channel is precision trimmed at manufacture and used by the digital processing circuitry as a reference for channel gain calibration. When the circuit is powered for use, the other channels are calibrated based on the trimmed and calibrated reference. The need for providing the circuitry to precision trim all other channels but one is avoided by this invention.

Abstract: We have discovered that hydrogen-related loss in silica-based single mode transmission optical fiber can be reduced or eliminated by use of a substrate tube that contains hydrogen getter sites. Exemplarily, substrate tubes according to the invention are doped with Ge or P.

Abstract: Disclosed is a voltage and current protector device designed for connecting blocks with a high density of contacts. Thermal overload protection is provided through a special ground connector with one end mounted over the surge protector element rather than through the normal ground pin of the element. The ground connector at its other end is shaped into a detent for capturing the ground bar of the connecting block.

Abstract: A ring oscillator having an even number of differential amplifier stages is disclosed wherein each stage includes a differential amplifier using two N-channel MOSFETs whose gates serve as the inputs and whose drains serve as the outputs of the stage. The sources of the two MOSFETs are connected together and to a current sink consisting of a cascoded structure of N-channel MOSFETs. The drains of each of the two N-channel MOSFETs serving as the differential amplifier are each connected to a respective current source provided by a P-channel MOSFET. All of the current sinks in the stages are connected as secondary legs of a first current mirror which establishes a current of I in the sinks. All of the current sources are connected as secondary legs of a second current mirror which attempts to establish a current of (1+.varies.)I/2 in each of the sources, where .varies. is a number greater than zero.

Abstract: Apparatus for providing displays in which the locations of nodes of a graph relative to each other are a function of the significance of a relationship between the nodes. The technique used to locate the nodes produces groups of nodes with significant relationships to each other which are set visually apart from the other nodes. The relationships between the nodes are defined by using a statistic to give weights to links between the nodes. Statistics may also be used to determine the size, shape, and color of the nodes and the color and width of the links. The display may also include histograms which show the numbers of links or nodes which have given values of the statistics and which relate the colors in which the nodes and links are displayed to values of the statistics. The histograms may further be used to interactively define masks for links and nodes, and masked links and nodes are not taken into account in making the display.

Abstract: Disclosed is a low bit rate audio and video communication system which employs an integrated encoding system that dynamically allocates available bits among the audio and video information and the manner in which the audio and video information will be perceived by a viewer. A dynamic bit allocation and encoding process will evaluate the current content of the audio and video information and allocate the available bits among the audio and video signals to be encoded based upon the perceptual significance of that information. A face location detection subroutine will detect and model the location of faces in each video frame, in order that the facial regions may be more accurately encoded than other portions of the video frame. A lip motion detection subroutine will detect the location and movement of the lips of a person present in a video scene, in order to determine when a person is speaking and to encode the lip and face regions more accurately.

Abstract: Articles according to the invention comprise an improved organic thin film transistor (TFT) that can have substantially higher source/drain current on/off ratio than conventional organic TFTs. An exemplary TFT according to the invention comprises, in addition to a p-type first organic material layer (e.g., .alpha.-6T), an n-type second organic material layer (e.g., Alq) in contact with the first material layer. TFTs according to the invention can be advantageously used in, for instance, active liquid crystal displays and electronic memories.

Abstract: By teleconferencing participants (201-1-201-N.sub.1, 202-1-202-N.sub.2, 203-1-203-N.sub.3), who are grouped in diverse geographic locations with a multi-stage system, a significant improvement in the use of interexchange facilities is achieved. The signals transmitted by the telecommunications devices (e.g., telephones) of a group of conference participants located in the same general geographic area are inputted to a first stage bridge (210, 211, 212). Each first stage bridge measures the signal power of each signal and outputs on separate telephone circuits (218, 219, 220), a predetermined number of signals (for example, three) that have the highest signal power. These three signals are transmitted on the interexchange facilities (206) to a second stage bridge (216) to which similar groups of signals from other first stage bridges in other locations are also transmitted.

Abstract: Apparatus 500 for storing a variable quantity of strand material 200 comprises a generally cylindrical drum 110 that stores a layer of elongated strand material around its exterior surface. The layer is formed by wrapping the strand material in adjacent convolutions around the exterior surface which is energized to move in a direction which is parallel to the central axis 101 of the drum. Consequently, the strand material also moves in a direction that is parallel to the central axis. A winder assembly 510 is mounted on a first shaft 140 at an input end of the drum, and includes a strand payout member 511 for depositing strand material onto the drum. The drum is mounted on a second shaft 150 which contains the common support structure of the drum and the equipment for energizing the exterior surface. An unwinder assembly 520 is mounted on a third shaft 160 at the output end of the drum, and includes a strand-receiving member 521 for removing the strand material from the drum.

Abstract: A transporter vehicle comprises two lifting devices which carry respective jacks and which can be joined at their ends by cross bars to form a rectangular dolly with a central opening therein. The lifting devices each have front and rear wheels so that the dolly can be rolled on floor surfaces. In practice, the two are placed on opposite sides of a load seated on a floor in the opening between those devices, the jacks are placed under the load, the cross bars are assembled with the side frames, the load is jacked up on its opposite sides to be above the floor and the load may then be transported.

Abstract: The invention discloses a method and apparatus for assigning link "distance" metrics that result in near optimal routing for a network formed of nodes (routers) and links, where each link has a capacity associated with it, and where source-destination flows are given. The routing optimality is measured with respect to some objective function (e.g., average network delay).

Abstract: A spread spectrum code pulse position modulated communication system is disclosed. The frequency spectrum of a transmitted signal is spread by encoding bits with a predefined spectrum-spreading codeword which is in accordance with regulatory requirements or other standardization decisions. When the predefined spread spectrum codeword is passed through a filter matched to the characteristics of the codeword, a peak is detected in the main lobe. A positive main lobe can indicate a binary value of "0" and a negative main lobe, associated with the inverse of the predefined codeword, can represent a binary value of "1". Additional information is conveyed by modulating the position of the center of the codeword within the symbol duration. In one embodiment, the position of the center of the codeword is varied among eight positions. Thus, eight signal states are available, and three additional bits may thereby be conveyed.

Abstract: Through-the-lens alignment during deep UV lithographic processing in the manufacture of VLSI is accomplished without shifting the mask or wafer from the exposure position. Introduction and extraction of alignment light of actinic wavelength depends on beam routing due to diffraction from an interference grating. The path of alignment light is within the focusing system but does not impinge on the focused pattern.

Abstract: A method and system for implementing an application protocol between a communication network subscriber and a caller. The system uses a Customer Transaction Profile (CTP) database to store protocol definitions for network subscribers. Each protocol definitions specifies the type nd format of input messages that a subscriber excepts to receive, and the type and format of output messages that the subscriber excepts to send. When a caller attempts to contact the subscriber, the network retrieves the subscriber's protocol definition and uses it to translate communications between the subscriber and the caller.

Abstract: An optical line terminal of the type including sets of optical signal processing components arranged in an identical manner in mutually redundant parallel branches includes an input switch that routes an incoming optical signal for processing into either one of two branches to the exclusion of the other. Following amplification, a part of an optical signal propagating in the one branch is branched-off and routed through the same input switch into the other branch to be processed therein identically to the one branch processing for monitoring the status of the other branch. On detection of faulty processing in the one branch, the input switch is switched into its other state in which it reroutes the incoming optical signal into the other branch for processing therein, while also routing a part of the amplified optical signal from the other branch into the one branch for monitoring the one branch.