Abstract: Method and apparatus for minimizing retransmissions during communication in a modem-to-modem communications system.

Abstract: Method and apparatus for capturing and saving recently dialed telephone numbers and for redialing automatically a telephone number from among the most recently dialed telephone numbers. Embodiments of the present invention: (a) capture an outgoing telephone number when it is dialed by a caller; (b) enter the telephone number into a database comprised of the last N telephone numbers that were dialed, where N is a predetermined number of telephone numbers, while eliminating duplicative entries for a particular telephone number; (c) display the telephone numbers in the directory in response to caller input; and (d) cause a telephone number in the directory to be redialed in response to caller input.

Abstract: A packing pallet which provides increased buckle resistance for a given amount of cushioning material. In particular, an inventive packing pallet utilizes a stringer as a bottom support for cushions and a top deck board which is bolted, through the cushions, to the stringer.

Abstract: Package for electronic components of a switch, which switch includes sensing components such as thermistor, measuring components, and output-control components, some of which components are relatively highly power-dissipative. A first portion of the switch supports the thermistor in a bushing wherein the head of the thermistor is bonded to the bushing with an electrically insulating material and the head of the thermistor is bonded to a wall of the package with a thermally conductive material, all of which bonding provides shock and vibration protection for the thermistor. Heat is removed from the highly power-dissipative components by a thermally conductive material which conducts heat from the components to a surrounding capsule and by wires which connect the switch to outside circuit components.

Abstract: Method and apparatus for detecting and sectionalizing troubles on telephone lines automatically. Specifically, an embodiment for detecting and sectionalizing troubles on a telephone line connecting a switching machine and a subscriber telephone set connected thereto over the telephone line, includes apparatus which: (a) emits a pulse over the telephone line; (b) detects reflections of the pulse; and (c) and determines whether a reflection was received prior to the expiration of a predetermined time period. The predetermined period relates to a distance which is less than the length of the telephone line between the switching machine and the subscriber telephone set.

Abstract: An ANI Converter System (ACS): (1) logically interfaces between: (a) a telephone network, on the one hand, and customer premises equipment (CPE), on the other hand, or (b) two portions of a switched telephone network, such as two tandem toll switching machines; (2) accepts incoming calls; (3) extracts in-band network routing and/or origination information such as ANI information; (4) uses the information to extract relevant information from a data base; and (5) places a call to a predetermined called party at, for example, a predetermined workstation to aid operators using the workstation in carrying out transactions with a calling party.

Abstract: Multiple-head tool such as a multiple-head screwdriver includes an electrically insulated handle; a shaft which has one end inserted into the handle; a multiple-headed bit which is mounted to rotate within a slot in the other end of the shaft; and an electrically insulated sleeve which is mounted to move along the shaft and to rotate about the shaft. In use, the multiple-head bit is rotated so that the desired head extends outward from and substantially parallel to the shaft and another tool or a spur is disposed within and substantially parallel to the slot. The sleeve is then moved down the shaft to cover at least a portion of the slot to enclose and hold the head or spur disposed therein rotationally fixed.

Abstract: Method and apparatus for sectionalization and self-diagnosis of loop start and ground start trunk interfaces without intervention from host telephone company equipment. The inventive method entails the use of an isolation relay in the trunk circuit to isolate the trunk circuit electrically from the physical medium and to apply various signals to portions of the isolated trunk circuit to carry out specific self-diagnostic tests.

Abstract: Continuously tunable, biased, semiconductor superlattice electron interference filter/emitter which can serve, for example, as a hot electron emitter in a ballistic transistor, provides energy selectivity for substantially ballistic electron wave propagation at electron energies above the superlattice potential barriers. The layers of the biased superlattice have alternatively high and low electron refractive indices wherein each layer is a quarter or half of an electron wavelength in thickness and wherein the quantum well barrier widths are adjusted in the direction of emission to provide the desired energy selectivity.

Abstract: Method and apparatus for identifying telephone signals which are produced by a human voice. The method includes determining a measure of the energy of predetermined frequency bins of the frequency spectrum of the signal for a frame comprised of a predetermined number of consecutive samples of the signal, if the signal is an analog signal; averaging the measure of the energy of the predetermined frequency bins over a predetermined number of frames to provide a frame group average energy measure; determining the sum of the absolute value of the difference between the frame group average energy measure for all pairs of frame groups which are consecutive in time; and comparing the sum with a predetermined amount to identify the signal as having been produced by a human voice if the sum exceeds the predetermined amount.

Abstract: A pipe pulling grip for use, for example, in pulling irrigation pipe underground includes a chain, a tapered nose cone, a hollow pipe, and a pipe grip. The chain is affixed to the tapered portion of the nose cone and the other end of the nose cone is affixed to one end of the pipe. Lastly, one end of the pipe grip is affixed inside the pipe.

Abstract: Semiconductor, quantum well, electron and hole slab waveguides include a substrate semiconductor layer, a film semiconductor layer, and a cover semiconductor layer, wherein the semiconductor layers provide substantially ballistic transport for electrons and wherein the thicknesses and compositions of the semiconductor layers are determined in accordance with the inventive method to provide a waveguide.

Abstract: Semiconductor structural elements with four regions of alternating conductivity type have a stored charge characteristic which becomes apparent as so-called "tail" current upon switching off. The tail current can be reduced by means of an anode-side emitter region containing damaged regions generated by laser bombardment which extend through a pn-junction formed between the anode-side emitter region and a central region up into the central region.

Abstract: Apparatus for removing tissues such as vitreous humer from an eye has an outer needle having an aperture near one end; an inner tube disposed partially within the outer needle, having a sharp end and another end to which a vacuum is applied; a drive system for reciprocating the inner tube within the outer needle so that the sharp end of the inner tube reciprocates across the aperture to cut tissue; indexing means so that the inner tube does not rotate with respect to the outer needle; and venting means for releasing compressed air.

Abstract: Method for altering an electrical characteristic of a circuit having at least one active semiconductor device involves applying at least one pulse--a voltage pulse, a current pulse, an energy pulse, or a power pulse and so forth--across the active semiconductor device, the pulse having sufficient amplitude of one or more of its electrical parameters and time duration to alter the electrical characteristics of the device, and thereby, the electrical characteristic of the circuit. The pulse is applied across the junction by applying it to at least one terminal or electrode which is contacted to semiconductor material disposed within the device.

Abstract: Apparatus and method for measuring the transmission quality of a telephone line, for example, a telephone line connected between two voice processing systems. The apparatus includes means for generating a predetermined sequence of DTMF pulses having predetermined amplitude values and for transmitting them over a telephone line; means for receiving DTMF pulses from a telephone line and determining the value of each pulse; means for counting the number of received DTMF pulses; and means for comparing the number with a predetermined threshold value, whereby the telephone line is determined to have acceptable transmission quality if the number exceeds the predetermined threshold value. Further, in a preferred embodiment, the predetermined sequence of DTMF pulses comprises four groups of ten (10) DTMF pulses, each of which groups has succeedingly lower amplitude.

Abstract: A Call Filter System (CFS): (1) logically interfaces between a public telephone network and business customer premises equipment; (2) automatically processes incoming and outgoing calls which are amenable to such intervention; and (3) enlists the aid of human intervention on calls requiring such intervention.

Abstract: Apparatus for detecting a single-frequency signal having a predetermined frequency in an analog signal includes means for converting the analog signal to a differentially encoded digital signal and detection means for detecting a single-frequency signal having the predetermined frequency from the differentially encoded digital signal. In a preferred embodiment, the detection means includes: means for detecting one cycle of the analog signal by detecting a signal maximum followed by detecting a signal minimum which is followed, in turn, by detecting another signal maximum; means for determining the length of the cycle, for determining whether the length is within predetermined bounds, and for keeping a count of such occurrences; and means for determining whether the count has reached a predetermined amount, whereby a single-frequency signal having the predetermined frequency has been detected.

Abstract: A low noise doped quantum well avalanche photodector (APD) having repeated superlattice units. Where the majority carriers are electrons, each unit is formed from p.sup.+ -n.sup.+ layers of a first material having a first ionization threshold, a near intrinsic layer of a second material having a smaller ionization threshold, and a near intrinsic layer of the first material. Such an APD can be fabricated in the GaAs/AlGaAs material system.