Abstract: Material comprising an effective amount of a novel intermetallic bulk superconductor compound is disclosed. The compound has the composition LnNi.sub.2 B.sub.2 C, with Ln being Y or a rare earth (atomic number 57-71), preferably Tm, Er, Ho or Ln. A compound of composition XPt.sub.2 B.sub.2 C, with X=Y and/or La, is also a superconductor.

Abstract: There is disclosed a soft symbol for use in a decoding process generated from a binary representation of a branch metric. When a hard decision bit is a zero, a preselected number of bits of a binary representation of the branch metric are concatenated with a hard decision bit to form the soft symbol. When the hard decision bit is a one, the ones complement of the preselected number of bits of the binary representation of the branch metric are concatenated with the hard decision bit to form the soft symbol. The concatenation function can be achieved using an exclusive OR function with the preselected bits of the binary representation of the branch metric and the hard decision bit to form the soft symbol. The hard decision bit may be selectable from more than one source.

Abstract: The invention is an improvement of a method for selectively etching a first surface of each of a plurality of wafers (21-23) comprising the steps of masking the entirety of each wafer except certain exposed portions to be etched on the first surface, and immersing the wafers in a heated etch bath (34) for a sufficient time to etch V-grooves (11) into the first surfaces. In one embodiment, the wafers are arranged in the etch bath with the first surface of each wafer (the surface to be etched) facing the first surface of another wafer. The first surfaces of all of the wafers are substantially parallel and are all substantially transverse to a bottom surface of the vessel containing the etch bath. The bottom surface of the vessel is heated to make in the etch bath a temperature gradient that is at a maximum at the bottom surface of the vessel and a minimum at the top surface of the bath.

Abstract: Briefly, in accordance with one embodiment of the invention, an extendible local area network includes a hub station including a memory and at least one hub station segment. The hub station segment is adapted to be coupled to at least N other hub station segments by a bi-directional control signal bus, N being a positive integer. The hub station segment includes at least two ports, each of the ports being adapted to receive electrical signal packet transmissions from a remote station. The memory and the hub station segment are mutually coupled by a signal bus.

Abstract: An optical packet switch which receives data packets and switches those data packets in the optical domain without using recirculation devices is provided. The switch staggers the data packets in time to avoid packet collisions within the switch. The switch includes two stages that are coupled by optical delay lines. The non-blocking stages include a scheduling stage and a switching stage. Incoming data packets are received at the scheduling stage and are output to appropriate optical delay lines. The scheduling stage and the delay lines ensure that the data packets do not collide when the packets are switched at the switching stage of the optical switch.

Abstract: An optical appliance includes at least one input waveguide and a first free space region connected to the input waveguide. A first plurality of waveguides is connected to the first free space region. An optical grating, which is connected to the first plurality of waveguides, includes a plurality of unequal length waveguides that are divided into at least three waveguide groups. Adjacent waveguides that belong to the same group have a substantially constant path length difference between them while adjacent waveguides belonging to different groups of waveguides have a path length difference between them that differs from the constant path length difference by an odd integer multiple of one-half a preselected wavelength. A second plurality of waveguides is connected to the optical grating and a second free space region is connected to he second plurality of waveguides. At least one output waveguide is connected to the second fee space region.

Abstract: A coiled cable handling apparatus uses a platform with retractable fingers to maintain the coiled configuration of a coiled cable. The coiled cable having a coiled portion, a first end thereof terminating in a connector and a second end. The reactable fingers contact the inner circumference of the coiled cable, a centrally located nest or clamp secures one end of the cable and a clip secures the other end of the cable. A cable transport mechanism places the coiled cable on the platform or removes it from the platform. The transport mechanism comprises coil pickup clamps to grasp the coiled section of the cable, a clamp to grasp the end of the cable secured by the platform's centrally located clamp, and a clamp to grasp the other end of the cable.

Abstract: Applicants have discovered that gallium arsenide surfaces can be dry passivated without heating or ion bombardment by exposing them downstream to ammonia plasma formation. Specifically, a workpiece having exposed gallium arsenide surfaces is passivated by placing the workpiece in an evacuable chamber, evacuating in the chamber, generating an ammonia plasma removed from the immediate vicinity of the workpiece, and causing the plasma products to flow downstream into contact with the workpiece. Preferably the plasma gas pressure is 0.5 to 6.0 Torr, the substrate temperature is less than 100.degree. C. and the time of exposure is in excess of 5 min. The plasma should be generated at a location sufficiently removed from the workpiece that the workpiece surface is not bombarded with ions capable of damaging the surface (more than about 10 cm) and sufficiently close to the workpiece that reactive plasma products exist in the flow (within about 30 cm).

Abstract: The routing of telephone calls in a telecommunications network is enhanced by providing a method for associating a plurality of telephone numbers assigned to a particular subscriber with respective codes such that a caller may dial one of the subscriber's telephone numbers and a code associated with another one of the subscriber's telephone number in order to direct the routing of the call to the latter telephone number.

Abstract: In accordance with the present invention, a technique for efficiently utilizing memory in determining which next state accumulated cost to retain, such as in a communication system or a Viterbi decoder. The system includes a memory having a portion of registers allocated to a first array and a portion of registers allocated to a second array. The technique includes retrieving a present state accumulated cost from a storage register of the first array and calculating a next state accumulated cost based on the present state accumulated cost. The next state accumulated cost is stored in a storage register of the second array. The second array is designated as containing present state accumulated costs. A present state accumulated cost is retrieved from a storage register of the second array and used in calculating a subsequent next state accumulated cost. The subsequent next state accumulated cost is stored in a storage register of the first array.

Abstract: A computer input device for use as a computer mouse or keyboard comprises a thin, insulating surface covering an array of electrodes. Such electrodes are arranged in a grid pattern and can be connected in columns and rows. Each column and row is connected to circuitry for measuring the capacitance seen by each column and row. The position of an object, such as a finger or handheld stylus, with respect to the array is determined from the centroid of such capacitance values, which is calculated in a microcontroller. For applications in which the input device is used as a mouse, the microcontroller forwards position change information to the computer. For applications in which the input device is used as a keyboard, the microcomputer identifies a key from the position of the touching object and forwards such key identity to the computer.

Abstract: A process for fabricating transistors on a substrate is disclosed. In accordance with the process, stacks of material are formed on the surface of the substrate. Walls of silicon dioxide are created around the stacks in order to insulate the material within the stacks from the material deposited outside of the walls. A first layer of polycrystalline material is deposited over the substrate and selectively removed such that only those portions of the polycrystalline layer that surround the stacks of material remain. A layer of silicon nitride or silicon dioxide is then formed over the substrate surface. A first resist is then spun on the substrate surface. This resist aggregates near the stacks of material. An isolation mask is generated that leaves exposed only those areas of the substrate that correspond to the area of overlap between the first polycrystalline area and the stacks of material, which also contain a layer of polycrystalline material.

Abstract: Transmission of clock signals at the pump wavelength of an optical amplifier utilized to amplify data signals being communicated in an optical network. The clock signals synchronize the data signals to a terminal utilizing the optical network. The pump wavelength is generated by a pump laser which supplies the amplification power for the optical amplifier. The clock signals are communicated on the pump optical wavelength by directly modulating the pump laser or by using an external modulator which inhibits the transmission of the pump laser's output.

Abstract: A system combining LAN and telecommunication capabilities to provide a high speed wireless LAN capability and to simultaneously provide wireless ISDN capability within an office. The LAN and ISDN information is communicated over a common transmission medium. The system also allow a user to interconnect wireless ISDN digital terminals to any other ISDN equipment anywhere in a PBX switch system or the public network. The system provides for communication of information between wireless LAN units and ISDN equipment. For example, this function allows a local computer using a local LAN interface to communicate with a remote computer via ISDN switching facilities. Further, the expense of hiding unsightly wiring in an office environment can be avoided, and the cost of moves and rearrangements of equipment can be greatly minimized.

Abstract: Transitions of a mobile radiotelephone between operating on A band service and B band service are controlled to enable the mobile radiotelephone to utilize the bands of a single service provider over a wide area of cellular service areas in which service is provided on either A or B bands by that single service provider. Each mobile radiotelephone served by a single service provider has an extended home system identification entered into its number assignment module (NAM). When the mobile radiotelephone is operating in a roam mode it scans both the A and B bands searching for the extended home system identification. If the system is successful in locking onto one of the extended home system identification channels the mobile radiotelephone uses that setup channel to establish and receive calls from its original service provider within the present service area. If the lockup can not be made the mobile radiotelephone uses the system I.D. and the A or B band as normally set in the NAM.

Abstract: A method of tailored error protection coding is disclosed. An illustrative coding method according to the present invention concerns encoding a first signal and a second signal to provide error protection for the signals, wherein the first signal requires greater error protection than the second signal. According to the method, the first signal is encoded with a first error protection code. The encoded first signal is then combined with the second signal. The combination of the encoded first signal and the second signal is further encoded with a second error protection code to generate a combined error protected signal, wherein the first signal is coded with both the first and second error protection codes. A second embodiment concerns the use of separate coders which apply different error protection codes to two signals. The two encoded signals are then combined into a single signal.

Abstract: This disclosure describes a physical design for an ocean floor trenching tool. The tool consists of a replaceable forward-extending plowguard and detachable hardened plow tips. Surfaces forming the tool's mouth around the plowguard cause the tool to penetrate the ocean bed under normal operation. The surfaces are also effective to "spoil" or break up the compacted bed for easier tool advancement. If an unplowable obstacle is encountered, the plowguard prow rides up and over it, clearing the plow tips away from potential damage. Once past the obstacle, the tool again planes down to operating depth. The tool is useful as a plowability assessment device. With addition of a cable-burying rear chute, the tool can also bury repeatered or repeaterless cable.

Abstract: A wide variety of call traffic is effectively integrated in a single broadband communications network. Calls having widely differing bandwidth requirements and sensitivities to delay are handled by the network with efficient, effective, and fair bandwidth allocation and transmission scheduling. This is accomplished by classifying each call in accordance with certain signal characteristics, such as required bandwidth and sensitivity to delay. Each call class is directed to a separate queuing circuit. Some calls in certain classes, such as those associated with high-bandwidth constant bit rate services, are each directed to their own individual queuing circuits. Other calls within a class are statistically multiplexed into a single queuing circuit for that class.

Abstract: Cave plots are a graphical techniques for comparing two time series using overlapping and opposing coordinate systems. The plots are space-efficient, allowing comparisons involving many data points and can be used with irregularly-spaced time series.

Abstract: A submarine optical fiber cable adapted for use in shallow-water submarine applications having the economy of non-armored cables with the robustness of armored cables is disclosed. The optical fiber cable comprises a plurality of longitudinally extending strength members arranged in a single layer around a single longitudinally extending central tube in a substantially close fitting manner. Disposed within the central tube is at least one optical fiber. In an illustrative example of the invention, six galvanized steel strength members are arranged in a close fitting manner around a hermetically sealed central steel tube, where the tube and the strength members have substantially identical outside diameters, so as to form a strong and stable shell. Plastic water-blocking material is disposed in the interstices between the strength members and the tube. Insulated conductors are disposed in grooves formed between adjacent strength members.