Abstract: A power factor compensator (18) for a power converter (17) comprises an L-C circuit connected in series between the power converter and the converter's A.C. power source (13). The values of the inductor (30) and the capacitor (31) of the compensator circuit are selected to cause the L-C circuit to resonate at a frequency higher than the power source frequency, preferably at a frequency ranging between 1.4 and 3.5 times the power source frequency, in order to achieve a power factor within the range of about 0.65 to 0.95. A resonant frequency of about twice the power source frequency has been experimentally found to give particularly good performance.

Abstract: An integrated voice and data network includes a multiplexer arranged with a voice queue for storing voice packets and a data queue for storing data packets. Voice packets are transmitted for a predetermined interval T1. Data packets are transmitted for a predetermined interval T2. The predetermined intervals T1 and T2 may be of different durations. A separate signaling queue can be provided for storing received signaling messages. If a signaling message is moved into the separate signaling queue during either interval T1 and T2, that interval is suspended and the transmission of voice or data packets is interrupted until the entire signaling message is transmitted. Then the interrupted voice or data transmission is resumed for the remainder of the suspended interval T1 or T2. As an alternative, signaling messages can be transmitted during predetermined intervals between the intervals T1 and T2. Block dropping of low order voice bits also is described for reducing congestion at the node.

Abstract: The present invention relates to a multichannel multihop lightwave communication network which allows packet concurrency in the network while avoiding the need for agile optical devices. The network comprises a lightwave communication medium (10) for supporting a plurality of independent user nodes; and a plurality of N network interface units (NIUs) (11). Each NIU is connected to the lightwave medium and one or more separate user nodes and comprises a trnasmitter section (28-35) and a receiver section (20-27) which are each fixedly assigned to transmit and receive, respectively, over a single channel or a plurality of separate channels to or from other NIUs of the network. In a connectivity pattern for one embodiment of the network, the NIUs are divided into k groups of p.sup.k NIUs such that each NIU of a first group of p.sup.

Abstract: Processors (101) of a multiprocessor system (FIG. 1) communicate across bus (150) via a low-latency packet protocol featuring per-logical channel input queues (143) and output queues (144), different per-processor priorities for sending data packets (FIG. 10) and data packet-acknowledging "quick" messages (FIG. 11), and separate buffers (923; 918) for receiving data packets and "quick" messages, respectively. Transmitted data packets afflicted by error, receive buffer overflow, and input queue-full conditions are discarded by the receiving processor and are retransmitted by the sending processor.

Abstract: An speech analysis and synthesis system where pitch information for excitation is transmitted during voiced segments of speech and modified residual information for excitation is transmitted during unvoiced speech segments along with linear predictive coded (LPC) parameters. The speech analysis portion of the system uses a pitch detection circuit to determine when the speech is voiced or unvoiced and to calculate the pitch information during voiced segments. A multi-pulse excitation forming circuit generates the modified residual signal which is obtained from the cross correlation of the residual signal and the LPC-recreated original signal. The pitch detection circuit controls a multiplexer which selects either the output of the multi-pulse excitation forming circuit or the output of the pitch detection circuit for transmission as the excitation information with LPC parameters to the synthesizer portion of the system.

Abstract: A circuit is disclosed which converts CMOS logic input signals to ECL output signals. A pair of FETs, arranged as a conventional CMOS inverter, responds to the CMOS logic input signals and drives a bipolar transistor operating as a voltage follower. The emitter of the bipolar transistor serves as the output of the buffer providing the ECL output signals. A resistor having a predetermined resistance couples between a voltage source and the base of the bipolar transistor. First one of the pair of FETs couples a constant current source to the resistor and the base of the bipolar transistor when the buffer is supplying an ECL logical "zero" logic signal. The current from the current source passing through the resistor establishes the ECL logical "zero" output voltage. Second one of the pair of FETs shunts the resistor when the buffer is supplying an ECL logical "one" output, allowing faster transitioning of the output of the buffer from an ECL logical "zero" to a logical "one".

Abstract: In an optical switching network, a master optical space switch is interconnected with remote slave equipment for switching block-multiplexed messages among the remote equipment. The master optical space switch responds to a frequency reference clock and steps through a sequence of states, or configurations, for establishing various routes among the remote equipment for appropriately routing the messages to correct destinations. The frequency reference clock also is distributed to the remote equipment. During one of the states per frame, each remote slave equipment transmits a distinct signature signal. All of the slave equipments are connected through the master optical space switch to return to themselves their own signals transmitted during that time slot. Each remote slave equipment compares the returned signal with the originally transmitted signature signal to determine how much the round trip delay has varied from a nominal value.

Abstract: A preform for fabrication of a glass fiber optical transmission line is prepared by chemical reaction of vapor ingredients within a glass tube. Reaction, which may be between chlorides or hydrides of, for example, silicon and germanium with oxygen, occurs preferentially within a constantly traversing hot zone. Flow rates and temperature are sufficient to result in glass formation in the form of particulate matter on the inner surface of the tube. The particulate matter deposits on the tube and is fused with each passage of the hot zone. Continuous rotation of the tube during processing permits attainment of higher temperatures within the heated zone without distortion of the tube.

Abstract: Cordage (17) which may be used for any of the commonly marketed lengths of etractile cords comprises an array of a plurality of conductors (11--11) each insulated with a suitable plastic material. The array of conductors is enclosed in inner and outer jackets (52, 54). The inner jacket comprises a polyvinyl chloride (PVC) plastic material, for example, and has a thickness of about 0.015 inch. Covering the inner jacket is an outer jacket comprising a polyvinyl chloride plastic material having a thickness of about 0.005 inch and having a colorant constituent. The PVC composition of the inner jacket is such that it is a less expensive composition than that of the outer jacket. Enclosing the outer jacket is a layer (56) which comprises a top coating material. The top coating material provides the cordage with enhanced retractibility and prevents discoloration as well as plasticizer migration from the outer jacket.

Abstract: Efficient high frequency operation of magnetic devices is achieved by utilizing ferrites that have a low power dissipation hysteresis characteristic and by designing these magnetic devices to operate within an operational range where all applied magnetic forces to the magnetic core have a substantially linear constant permeability response. Within this operational range the hysteresis loop of the selected ferrite material approximates an ellipse with very little area encompassed between the increasing and decreasing B-H locus of the hysteresis loop. The cyclic energy dissipation is significantly reduced as compared to conventional magnetic operations and high frequency operation can be achieved with very high efficiencies.

Abstract: A communications cable comprising a core of transmission media such as optical fibers, for example, disposed in a core tube and a sheath system (32) includes provisions for preventing the movement of water within the cable core. Water blocking provisions (26) are disposed in the core tube and may comprise a tape or a yarn, for example, or both. The tape may comprise substrate tapes between which is disposed a superabsorbent material in powder form which upon contact with water swells and inhibits the further movement of the water. In another embodiment, a water swellable yarn may extend longitudinally linearly with the optical fibers in the core.

Abstract: In a hybrid integrated circuit encapsulation process, each lead array (14) is encompassed by an elongated C-shaped barrier member (17) which clamps onto the portions of the lead array adjacent the substrate (11); that is, opposite sides of a slot (18) in the barrier member grasp opposite sides of the leads. Thereafter, the uncured RTV silicone (15) is dispensed onto the substrate, flows over and encompasses chips (12) mounted on the surface of the substrate and is prevented from flowing along the leads (14) by the C-shaped members (17), each of which, due to its configuration, constitutes a barrier to fluid flow, either along the length of the various leads or over the top of the C-shaped member. In one embodiment, levers (19) may be integrated onto the C-shaped member opposite the substrate to aid in prying open the slot to permit the leads to be easily inserted into the C-shaped member.

Abstract: To overcome the deleterious effects of the nonuniform frequency modulation response in semiconductor lasers due to current injection in direct frequency modulation applications, it has been determined that the linewidth enhancement factor .alpha. be made as large as possible. In one embodiment, distributed feedback lasers well suited for frequency modulation lightwave communication systems are designed to have an integrated feedback element such as a corrugation grating whose effective pitch is selected to cause the Bragg wavelength and, therefore, the laser operating wavelength to be longer than the wavelength at substantially the maximum gain or gain peak in the semiconductor structure without the grating. That is, the wavelength of the grating is effectively detuned toward the longer wavelength and lower energy side of the peak of the gain profile.

Abstract: A call appearance reservation arrangement where any number of the call appearances of a directory number are reservable, and where a reservation type is defined for the directory number such that calls to and from the reserved call appearances are processed in accordance with one of a number of possible reservation types, such types for example including: (1) origination only, (2) termination only, and (3) origination and priority termination only.

Abstract: A grating coupler is combined with a quantum well index modulator and an optical waveguide to alter the reverse or forward coupling characteristics between two different propagation modes of the system.

Abstract: An apparatus for attaching each of a successive pair of wires (12) to each of a pair of contacts (13), seated in opposed recesses (14) in a connector (16), comprises a base (18) on which a connector-carrying carriage (26) is slidably mounted for movement along an axis (24). Each of a pair of ram assemblies (32) is mounted on opposite sides of the path of travel of the carriage (26). Adjacent to each ram assembly (32) is a wire guide (58) which has an upwardly inclined pin (74) which provides a path for pulling a wire into alignment with a separate one of the ram assemblies (32). Once aligned with the ram assemblies, the wires 12 are then rammed by the ram assemblies against the corresponding contacts (13).

Abstract: Combinatorial (Boolean ) logical functions are provided in a programmable optical logic device by combining a symmetric self-electrooptic effect device (S-SEED) with a logic control element for optically programming the S-SEED to initiate logic operations in a predetermined mode. A predetermined reference threshold optical signal is applied to one input of the S-SEED while first and second optical data signals are jointly applied to another input of the S-SEED to permit the desired combinatorial logic operation to be performed on the optical data signals by the optical logic device. As such, the programmable optical logic device is said to perform threshold logic operations. Logic operations which may be programmed into the optical logic device include AND, OR and NOT functions. A single optical signal is provided as output from each optical logic device.