Abstract: A repeater for use in a digital wireless teletype-capable telephone receiver. The repeater includes a receiver for receiving an input signal and interpreting the input signal to identify Baudot characters represented by the input signal, and produce a receiver signal comprising identifications of the Baudot characters represented by the input signal. The repeater also comprises a transmitter which produces an output signal based on the receiver signal produced by the receiver. The transmitter generates the Baudot codes identified to it by the receiver. The repeater therefore removes distortion which may be present in the input signal.

Abstract: A differential FM detection of signals uses in-phase and quadrature phase signal components of a received signal in the detection process, wherein the in-phase and quadrature phase signal components are at a low intermediate frequency (IF). The in-phase and quadrature phase signal components are each amplitude limited, sampled at a prescribed sampling rate and filtered in a prescribed manner. Delayed versions of the filtered in-phase and quadrature phase signal components are generated and, then, signal products are generated of the delayed in-phase signal component and quadrature phase signal component, and the delayed quadrature phase signal component and in-phase signal component. The algebraic difference of the generated signal products is obtained to yield the desired data signal, e.g., symbols.

Abstract: A free-standing hollow micro-tube that provides, in some embodiments, a flexible support for a movable platform. The hollow micro-tube is actuated to flex at substantially lower voltages than solid supports. Consequently, articles incorporating the micro-tubes that may be actuated by electrostatic forces, such as an XY translation stage and an array of pedestal mirrors, operate at reduced voltages.

Abstract: A packet switch is configured for determining an equivalent bandwidth for use in GCAC. The equivalent bandwidth definition of the invention is derived by multiplying some known connection parameter such as, for example, a selected bandwidth value by a multiplier preferably computed and stored in look-up tables according to the invention. The appropriate multiplier for a given connection request associated with a call may then be found by accessing sets of the look-up tables based on one or more connection and/or network parameters. For each link in a path considered during GCAC, the product of the multiplication of the selected bandwidth value and the multiplier is then compared to the available bandwidth, AvCR, of the path links to determine if the path satisfies the connection request.

Abstract: The specification describes an optical transmission system for high speed, high capacity digital pulse transmission, i.e. at least 10 Gb/s at a duty cycle of at least 10%, which uses transmission fiber with a dispersion value greater than 20 ps/(nm-km) or more negative than −5 ps/(nm-km). The system operates in the pseudo-linear transmission mode (PLTM). In the PLTM it was discovered that pulse distortion decreases, i.e. eye closure penalty actually decreases, as the dispersion value increases. System performance actually improves by increasing the value of absolute dispersion of the transmission fiber.

Abstract: The present invention is a transmitter device and related system and method for use in high speed optical transmission systems. In one exemplary embodiment of the present invention, light from a laser diode output is split into two branches of orthogonal polarization (Eox, and Eoy) of substantially equal power. Polarization selectors coupled thereto are operable to select a specific polarization to be output to a corresponding external optical polarization modulator. A first polarization modulator, receives light from the polarization selector, for example, Eox, and modulates URZ data from a URZ coder thereon. A second polarization modulator receives light from the second polarization selector, for example, Eoy, and modulates delayed data (URZd) representative of the URZ data from the URZ coder thereon. The URZ data and the delayed URZd data may be combined at the transmitter, fiber channel or receiver for transmission over a single optical medium, for example, a fiber optic cable.

Abstract: A device including a probe plate including a plurality of test pins, a conductive layer disposed in proximity to the probe plate and including a plurality of openings therein corresponding the plurality of test pins and, an insulator layer disposed on the conductive layer and including a plurality of openings therein corresponding the plurality of test pins.

Abstract: Reverse jog play can be provided quickly and simply in a player that plays a recorded stream of inter-frame encoded digital video by storing, in intra-coded frame format, frames that were previously decoded by the player and are in the vicinity of the frame currently being displayed. The intra-frame encoded versions of the decoded frames may be digitally stored in random access memory (RAM) or in some other storage medium that is easily accessible. The number of previously decoded frames may be a fixed number essentially independent of the frame structure of the video stream. Alternatively, the player stores each decoded frame from a predetermined, e.g., the most recently or next to most recently decoded, intra-coded frame (I-frame) until the current frame. Thus, the number of useable stored frames is a function of the video stream structure, the design choices of the user, and the current frame being displayed.

Abstract: Our method of making high bandwidth silica-based multimode optical fiber comprises provision of a non-circular preform, and drawing fiber of chiral structure from the preform. The non-circular preform can be made by maintaining the inside of the tubular preform under reduced pressure during at least part of the collapse, resulting in a non-circular core and cladding. It can also be made by removal (e.g., by grinding or plasma etching) of appropriate portions of the preform, resulting in a circular core and non-circular cladding. In the latter case, fiber is drawn at a relatively high temperature such that, due to surface tension, the cladding assumes substantially circular shape and the core assumes a non-circular shape. The chiral structure is imposed on the fiber in any appropriate way, e.g., by twisting during fiber drawing the fiber alternately in clockwise and couterclockwise sense relative to the preform.

Abstract: A method is disclosed for deriving an optimum decision criteria to detect forward link power control bits by a base station from a reverse link signal. In managing the forward link received power, a mobile station commands the base station to incrementally alter the forward link transmit power, by sending periodic power control bits to the base station on a reverse link signal. The transmitted power control bits may be distorted by channel imperfections and multipath effects. The method disclosed derives an optimum decision variable for performing power control bit estimation at the base station. In a preferred embodiment, the optimum decision variable is computed by considering the in-phase and quadrature components of a single power control group received on the reverse pilot channel.

Abstract: Document type comparison and classification using layout classification is accomplished by first segmenting a document page into blocks of text and white space. A grid of rows and columns, forming bins, is created on the page to intersect the blocks. Layout information is identified using a unique fixed length interval vector, to represent each row on the segmented document. By computing the Manhattan distance between interval vectors of all rows of two document pages and performing a warping function to determine the row to row correspondence, two documents may be compared by their layout. Furthermore, interval vectors may be grouped into N clusters with a cluster center, defined as the median of the interval vectors of the cluster, replacing each interval vector in its cluster. Using Hidden Markov Models, documents can be compared to document type models comprising rows represented by cluster centers and identified as belonging to one or more document types.

Abstract: Methods and apparatus for wireless communication in systems such as omni-beam and narrow-beam fixed wireless loop (FWL) systems. In a first technique in accordance with the invention, referred to as code division duplex (CDD) time-slotted CDMA, uplink and downlink portions of the system are separated using code division duplexing, while the users within a given cell are also separated using codes, e.g., using time-slotted CDMA. In a second technique in accordance with the invention, referred to as time division duplex (TDD) time-slotted CDMA, uplink and downlink portions of the system are separated using time division duplexing, e.g., time slots, while the users in a given cell are separated using codes, e.g., time-slotted CDMA. Both the CDD and TDD techniques may make use of an electronically-steered beam which is designed to provide simultaneous coverage within a given cell for two or more users separated by codes.

Abstract: A comprehensive system and method for managing security in an electronic network. The method includes the steps of providing a plurality of security services, providing a plurality of security mechanisms, and linking the services and mechanisms with a plurality of security management functions. The method supports all associated security protocols in the electronic network while maintaining transparency for message exchange. Advantageously, the method of the invention readily provides compatibility with a plurality of environments, network types, and technologies. The method provides five functional hierarchical layers, one protocol handling access to the layers, and includes a security management information base segmented according to the five functional layers. The five functional layers are, from the base, fundamental security primitives, security mechanisms, security services, security management functions, and security policies. Each layer can contain several independent modules.

Abstract: An analog to digital conversion (A/D) system produces a corrected output of an analog to digital (A/D) converter using at least one past signal sample. For example, the A/D system estimates a reference value or point, such as a reference amplitude, for the at least one past sample. In response to an indication that the A/D converter is saturated, the A/D system uses the reference value to predict a next reference value, such as a next amplitude value, from which a corrected digital sample value is produced to replace the saturating sample.

Abstract: Improved micro fuel cells suitable for portable electrical devices are provided, and processes for forming such cells. In one embodiment of the invention, silicon substrates are used both as the gas delivery structure for the fuel and the oxidant, and as the current collectors. Such use of silicon is advantageous in that it becomes possible both to utilize micromachining and lithographic techniques to form the desired structures, e.g., the gas delivery channels, and also to integrate the fuel cell with silicon-based control circuitry. Advantageously, the silicon substrates comprise both gas delivery tunnels and porous silicon gas diffusion regions formed over the tunnels in the surface of the substrate, i.e., the porous regions over the gas delivery tunnels are integral with the silicon substrate. In another embodiment of the invention, a monolithic structure is employed.

Abstract: An apparatus including at least one designated memory cell of a plurality of memory cells. Disposed within each designated memory cell is a resistance-altering constituent. Consequently, a first binary value is recognoized in each designated cell and at least a second binary value is recognized in each remaining cell.

Abstract: An optoelectronic phase locked loop for clock recovery in high-speed optical time division multiplexed systems. The optoelectronic phase locked loop includes a balanced photodetector through which the polarity ambiguity in error signal is resolved and the cancellation of laser noise enabling clock recovery with low timing jitter. The optoelectronic phase locked loop also includes an electroabsorption modulator as a phase detector, a lowpass filter, a variable controlled oscillator, a power divider and an amplifer.

Abstract: The method of channel estimation determines linear regression coefficients for N blocks of a first signal component in a received signal on a block-by-block basis, and determines a channel estimate based on the linear regression coefficients for the N blocks. Using the channel estimate, channel distortion in a second signal component of the received signal can be significantly eliminated.

Abstract: The present invention provides an optoelectronic device and a method of manufacture therefor, that prevents dopant diffusion and controls the dopant concentration therein. The optoelectronic device includes an active region formed over a substrate, and an interface barrier layer and barrier layer located over the active region. The optoelectronic device further includes an upper cladding layer located over the interface barrier layer and the barrier layer. In an exemplary embodiment of the invention, the interface barrier layer is an indium phosphide interface barrier layer and the barrier layer is an indium gallium arsenide phosphide barrier layer.

Abstract: A method for increasing the spectral efficiency of a transmitted signal. The signal includes a sequence of symbols selected from a set of symbols with each of the symbols having an associated numerical value. A symbol is output from the sequences symbols. A spectral sum is determined by summing the numerical values of all the symbols that have been previously output. A first sum is calculated by adding the numerical value of the next symbol to be output to the spectral sum. A second sum is calculated by subtracting the numerical value of the next symbol to the output from the spectral sum. The next symbol will be output with the positive phase if the first sum is less than the second sum. The next symbol will be output with the negative phase if the first sum is greater than the second sum. If the first sum equals the second sum the next symbol is output with either a positive phase or negative phase.