Abstract: An apparatus and a method for remotely indicating that a fax has been received. Received faxes are detected using an infrared emitter that sprays infrared energy into space that is open when no paper is present in the paper tray that receives incoming faxes at a fax machine, but which space is occupied by paper when a fax has been received. When there is no paper present in the paper tray, the infrared energy is lost in space. When there is paper present in the paper tray, the infrared energy is reflected back to and sensed by a photo transistor. When the photo transistor senses the presence of paper in the paper tray, a high-brightness light emitting diode is flashed to indicate that a fax has been received.

Abstract: A calibration system for a feed forward distortion reduction system periodically uses a pilot signal to calibrate the pilotless feed forward reduction system. In calibrating the feed forward distortion reduction system, the calibration system periodically injects the pilot signal onto a signal path, for example, when no signal is present on the signal path. A portion of the pilot signal on the signal path is provided to a feed forward path of the feed forward distortion reduction system. The pilot signal on the feed forward path is combined with the pilot signal on the signal path, and the calibration system adjusts the relative phase and amplitude between the pilot signal on the feed forward path and the pilot signal on the signal path to achieve the desired combination of the pilot signals.

Abstract: For use in a power supply having a rectifying diode and a snubber circuit that includes a snubber inductor for absorbing a portion of a reverse recovery current associated with the rectifying diode, a circuit and method for resetting the snubber inductor and a power supply employing the circuit and method. In one embodiment, the circuit includes a reset capacitor, coupled to the snubber inductor, that has sufficient capacity to impress a resetting voltage across the snubber inductor. The circuit also includes an activation circuit, coupled between the reset capacitor and an output of the power supply, that creates a voltage differential between the reset capacitor and the output to allow the reset capacitor to attain the resetting voltage.

Abstract: A method for allocating a fair bit rate for an ABR service. Forward and backward RM cells traversing a link 1 are received at an ATM switch. Both the forward and backward RM cells are associated with a session, with the forward RM cells being transmitted from a source to a destination and the backward RM cells being transmitted from the destination to the source. An advertised rate .gamma..sub.l for link 1 is updated when a backward RM cell associated the session is received based on a change in a bottleneck bandwidth .DELTA..lambda. of the session and a change in a bottleneck status .DELTA..beta. of the session. The explicit rate .lambda..sup.ER contained in the backward RM cell is rewritten as a minimum of the advertised rate .gamma..sub.l and the explicit rate .lambda..sup.ER. The backward RM cell is then transmitted to the source of the RM cell.

Abstract: There is disclosed, an active termination circuit includes a transmitter adapted to be coupled to a bidirectional conductor, a receiver also adapted to be coupled to the bidirectional conductor, a first impedance adapted to be switched to couple to the bidirectional conductor to match the input impedance of the receiver to a characteristic impedance of the bidirectional conductor to which it is adapted to be coupled when the receiver is in the receive mode, and a second impedance adapted to be switched to couple the bidirectional conductor to match the output impedance of the transmitter to the characteristic impedance of the bidirectional conductor to which it is adapted to be coupled when the transmitter is in the transmit mode.

Abstract: The system for auxiliary monitoring of emergency access calls functions to identify the geographical location of the origination point of the emergency access call and interconnects the appropriate emergency response agency that serves this geographic location to the emergency access call. The emergency access system is programmed to divide the covered region into a plurality of cells, with each cell defining a serving emergency agency and/or serving auxiliary emergency agency. Upon receipt of an incoming emergency call from a telephone station, the switching system determines the location from which the emergency access call originated, and which cell(s) define the serving emergency agency for this location. The system directs the incoming call to the designated emergency service agency as well as any serving auxiliary emergency agency that would be involved in the emergency response to the incoming emergency call.

Abstract: A communication system having a local network communicating with a remote network for assigning a dynamic Internet Protocol address to a communication device to enable a communication session between the communication device and an IP network The communication device sends an address request to the local network. If the local network does not selectively assign a local dynamic IP address, the address request is transmitted to a remote network to determine whether a non-local dynamic IP address from a remote pool of non-local dynamic IP addresses is able to be assigned. The communication system selectively communicates with other remote networks until a non-local dynamic IP address can be assigned to satisfy the address request. Once a non-local dynamic IP address has been assigned, the non-local dynamic IP address will be maintained for the duration of the communication session between the communication device and the IP network.

Abstract: Electronic apparatus is disclosed having components mounted within an environmentally sealed external enclosure. The external enclosure is made of heat conductive material and some of the components are mounted in heat conductive association with one or more walls of the external enclosure. The apparatus includes at least one heat pipe that has an evaporator in thermally conductive contact with a wall of the external enclosure proximate to one of the components. The condenser of the heat pipe is located outside the external enclosure and is provided with thermally conductive fins. Components that generate large amounts of heat can thus be provided with additional cooling reducing local hot spots. The external enclosure may be designed for the larger market in temperate climates, and be modified for hotter climates.

Abstract: An enhanced form of time switch. Serial bit streams received in input buffers are stored in parallel under program control in the cache of a pipe lined microprocessor. The microprocessor, under program control, then rearranges the received time slots and feeds them in parallel to output buffers from which serial bit streams are generated. Advantageously, program control is used to flexibly control the various functions of different time switches without requiring a change in the hardware.

Abstract: In accordance with the invention, a temperature-dependent rare earth doped waveguide optical amplifier is compensated by a temperature-dependent loss filter. The filter characteristics are designed to be temperature-dependent filters so that the gain characteristic of the amplifier is compensated over a practical operating temperature range. In essence, the amplifier comprises a length of optical waveguide for transmitting optical signals, a rare earth doped amplifying region in the waveguide for amplifying the transmitted optical signals, a pumping source for optically pumping the amplifying region, and a temperature-dependent loss filter. A typical design compensates an EFDA to a variation of less than 1 dB over a temperature range of -40.degree. C. to 85.degree. C. and a spectral range of at least 20 nm.

Abstract: In accordance with the invention, the piezoelectric layer of a SAW device is mechanically coupled to a substrate of temperature-sensitive material having a large coefficient of thermal expansion or contraction. In a preferred embodiment, the temperature-sensitive material is a nickel/titanium alloy having high negative coefficient of thermal expansion of about -200.times.10.sup.-6. The frequency of the device can be tuned by changing the temperature of operation.

Abstract: In accordance with the present invention, an address arithmetic unit provides a modulo addressing technique for addressing memory locations in a circular buffer. The address arithmetic unit includes a sign detector adapted to determine whether a sum of an address pointer and a precomputed comparison term is of a first state or a second state. A first adder adds an address pointer and a precomputed correction term to generate a first potential next address pointer. A second adder, operating in parallel with the first adder, adds the address pointer and a displacement to generate a second potential next address pointer. A selector adapted to select the first potential next address pointer as an output when the sign detector output and a sign bit of the displacement are different, and to select the second potential next address pointer as an output when the sign detector output and a sign bit of the displacement are the same.

Abstract: A programmable logic device, such as an FPGA, is implemented using logic cells that have configurable connection schemes between routing resources and logic element input pins. For example, in one embodiment, each logic cell in the device has a flexible input structure that supports two or more different connection schemes, which may or may not involve input sharing, where each logic cell can be individually programmed for any of the available connection schemes when the device is configured. As such, the device can be efficiently programmed to implement the user's specific circuitry. The invention balances the competing goals of (1) reducing routing requirements by limiting the number of connections between routing resources and logic element input pins and (2) providing minimally constrained programming of logic elements.

Abstract: The present invention is directed to a process for device fabrication and resist materials that are used in the process. The resist material contains a polymer that contains monomeric units that contain alicyclic formate moieties, and at least one other type of monomeric unit. The polymer may be formed by polymerization or by polymer modification of an existing polymer, and the resulting polymer either has alicyclic moieties incorporated into the polymer backbone or pendant to the polymer backbone via saturated hydrocarbon linkages. A preferred polymerization process is free radical polymerization, in which other monomers are selected for polymerization with the alicyclic moiety-containing monomer on the basis of the ability of the monomer to copolymerize by free radical polymerization.

Abstract: A repeater for extending the range of communications between a base station and a mobile unit without rendering the mobile unit incapable of communicating directly with the base station. In general, the polarization of the repeater input-antenna is different from the polarization of the repeater output-antenna such that sufficient isolation exists between the input and output antennas without substantially reducing the ability of the input antenna and the output antenna to receive signals from and output signals to the base station and the mobile units. In a preferred embodiment, the repeater input antenna is circularly polarized in one direction while the repeater output antenna is circularly polarized in a direction opposite from the input antenna.

Abstract: A wideband optical amplifier employs split-band architecture in which an optical signal passes through a common amplification stage and is then split to pass through parallel gain stages, each of which may be optimized for a particular band being traversed. A broadband grating reflector is used after the input gain section to reflect the signals of one of the bands so that they again will pass through the common input gain section before passing through gain section of the split structure dedicated to their particular wavelength. Meanwhile, the other signals pass through the reflector and move on through the gain section pertinent to their wavelength.

Abstract: The delineation and quick invocation of protection switching is achieved by generating a protection indicator having an initial state at the point that a transmission facility failure is detected and passing the indicator downstream. A switch that receives the indicator either increments or decrements the indicator in accordance with predetermined rules. However, a switch that receives the indicator when it reaches an active state immediately invokes protection switching if that switch is at the sink end of an associated protection path.

Abstract: A resistor-string DAC employing resistors of different value and a switching circuit for producing a differential analog voltage output which can be shaped with respect to an arbitrary common-mode voltage.

Abstract: The present invention relates to a computer method, apparatus and programmed medium for clustering databases containing data with categorical attributes. The present invention assigns a pair of points to be neighbors if their similarity exceeds a certain threshold. The similarity value for pairs of points can be based on non-metric information. The present invention determines a total number of links between each cluster and every other cluster bases upon the neighbors of the clusters. A goodness measure between each cluster and every other cluster based upon the total number of links between each cluster and every other cluster and the total number of points within each cluster and every other cluster is then calculated. The present invention merges the two clusters with the best goodness measure. Thus, clustering is performed accurately and efficiently by merging data based on the amount of links between the data to be clustered.

Abstract: An arrangement for lookahead interflowing traffic among a plurality of serving sites of one customer. Incoming calls received at a site are queued if they cannot be served immediately. Queued calls are then examined periodically and if the call has not yet been served by a local agent and if the call is one of the oldest call in the queue, then the call is a candidate for lookahead interflow. A candidate for lookahead interflow causes a message to be sent to another switch requesting that the call be interflowed. If the other switch accepts the call, the call is routed to that other switch; if the other switch does not accept the interflowed call then the call remains in the queue of the requesting switch and is reexamined at the next period. All calls in the queue are completed to a local agent if a local agent is available.