Patents Assigned to American Telephone and Telegraph Company AT&T Bell Laboratories
  • Patent number: 4873716
    Abstract: A method and apparatus for processing calls to a directory number, shared by a multiple number of terminals, in which a switching system selects a preferred terminal for serving the call based on call answering activity. The switching system establishes a connection to the preferred terminal. This system connection is for use in answering the call at the preferred terminal. Although the system connection is established to the preferred terminal, all the terminals sharing the directory number are enabled to answer the call. The arrangement dynamically selects the preferred terminal rather than establishing an initial system connection to only a statically defined terminal.
    Type: Grant
    Filed: December 27, 1988
    Date of Patent: October 10, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Patrick K. Brady
  • Patent number: 4873492
    Abstract: An automatic gain control circuit for an amplifier operating over a prescribed frequency range detects the output level of the amplifier; and couples a repeated predetermined waveform occurring at a rate greater than the reciprocal of twice the upper frequency of the prescribed frequency range to the output level signal. The waveform varying level signal is compared to a reference threshold to control the gain of the amplifier through a switched resistive elemement in the amplifier feedback path. The repeated waveform variations about the amplifier output level causes the value of the switched resistance to vary as a function of the output level. A low pass filter connected to the amplifier output removes switching transients resulting from the high frequency changes in the switched resistive element. The gains of a plurality of amplifiers may be determined by a common control for accurate tracking over a wide dynamic range.
    Type: Grant
    Filed: December 5, 1988
    Date of Patent: October 10, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Robert E. Myer
  • Patent number: 4873717
    Abstract: A call coverage arrangement in which coverage personnel are informed of the switch-hook status of covered terminals by way of a single two-part indicator on the coverage terminal. The two-part indicator indicates switch-hook status for any one of a number of covered terminals. The first part of the indicator identifies the covered terminal and the second part defines the switch-hook status of the identified terminal. The arrangement is flexible in providing coverage for additional terminals and in providing coverage via forwarding from any termianl, since there is no need to assign and dedicate status indicators to particular terminals.
    Type: Grant
    Filed: June 14, 1988
    Date of Patent: October 10, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Wayne A. Davidson, John P. Ernst, Marybeth Herkes, Ram Kuppuswami, Timothy A. Satalich, John J. Stanaway, Jr.
  • Patent number: 4872895
    Abstract: A method for forming articles which include silica-containing glass bodies, as well as the resulting articles, are disclosed. In accordance with the method, silica-containing gel particles are fused to form a glass body. In contrast to previous such methods, these particles are formed by mechanically, substantially uniformly subdividing either a substantially cohesive gel body, or an ungelled or partially gelled sol capable of yielding a substantially cohesive gel body, to form substantially uniformly sized, wet gel particles. Significantly, only substantially cohesive gel bodies which are also substantially elastic are useful in the invention, i.e., mechanical subdivision of non-elastic gel bodies results in these bodies undergoing plastic flow to yield non-particulate, pasty masses.
    Type: Grant
    Filed: December 11, 1986
    Date of Patent: October 10, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: James W. Fleming, David W. Johnson, Jr., John B. MacChesney, Sandra A. Pardenek
  • Patent number: 4871235
    Abstract: An optical system is disclosed which includes at least a first source of electromagnetic radiation (signal beam radiation), a device for processing the signal beam radiation, and a detector for detecting the processed signal beam radiation. The processing device functions, for example, as an amplitude modulator, a demultiplexer, or a switch, and includes a material region exhibiting a nonlinear optical response at one or more resonant wavelengths of electromagnetic radiation, as well as at least a second source of electromagnetic radiation (control beam radiation) for selectively inducing the nonlinear optical response. Significantly, the wavelength, duration and intensity of the control beam radiation are chosen to induce a resonant, nonlinear optical response, essentially free of any relatively slow component, in said material region at repetition rates higher than about 1.25.times.10.sup.4 Hz, or higher than about 3.3.times.10.sup.10 Hz, or even as high, or higher, than about 2.5.times.10.sup.11 Hz.
    Type: Grant
    Filed: June 9, 1988
    Date of Patent: October 3, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Benjamin I. Greene, Kuochou Tai, Mrinal Thakur
  • Patent number: 4872158
    Abstract: A high capacity metropolitan area network (MAN) is described. Data traffic from users is connected to data concentrators at the edge of the network, and is transmitted over fiber optic data links to a hub where the data is switched. The hub includes a plurality of data switching modules, each having a control means, and each connected to a distributed control space division switch. Advantageously, the data switching modules, whose inputs are connected to the concentrators, perform all checking and routing functions, while the 1024.times.1024 maximum size space division switch, whose outputs are connected to the concentrators, provides a large fan-out distribution network for reaching many concentrators from each data switching module.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: October 3, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Gaylord W. Richards
  • Patent number: 4872157
    Abstract: A high capacity metropolitan area network (MAN) is described. Data traffic from users is connected to data concentrators at the edge of the network, and is transmitted over fiber optic data links to a hub where the data is switched. The hub includes a plurality of data switching modules, each having a control means, and each connected to a distributed control space division switch. Advantageously, the data switching modules, whose inputs are connected to the concentrators, perform all checking and routing functions, while the 1024.times.1024 maximum size space division switch, whose outputs are connected to the concentrators, provides a large fan-out distribution network for reaching many concentrators from each data switching module.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: October 3, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Jayant G. Hemmady, William P. Lidinsky, Robert K. Nichols, Gaylord W. Richards, Gary A. Roediger, Scott B. Steele, Ronald C. Weddige, Bruce R. Zelle
  • Patent number: 4871420
    Abstract: By adjusting the AC field conditions, i.e., by grounding the environment of a substrate being etched with a chlorine-containing plasma, a significant increase in etch selectivity is achieved. By applying a similar AC field adjustment to the reaction chamber surfaces, excellent etch uniformity is achieved in conjunction with excellent selectivity.
    Type: Grant
    Filed: February 10, 1988
    Date of Patent: October 3, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Frank B. Alexander, Jr., Pang-Dow Foo, Ronald J. Schutz
  • Patent number: 4872159
    Abstract: A high capacity metropolitan area network (MAN) is described. Data traffic from users is connected to data concentrators at the edge of the network, and is transmitted over fiber optic data links to a hub where the data is switched. The hub includes a plurality of data switching modules, each having a control means, and each connected to a distributed control space division switch. Advantageously, the data switching modules, whose inputs are connected to the concentrators, perform all checking and routing functions, while the 1024.times.1024 maximum size space division switch, whose outputs are connected to the concentrators, provides a large fan-out distribution network for reaching many concentrators from each data switching module.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: October 3, 1989
    Assignee: American Telephone and Telegraph Company AT&T Bell Laboratories
    Inventors: Jayant G. Hemmady, William P. Lidinsky, Gary A. Roediger, Scott B. Steele, Ronald C. Weddige, Bruce R. Zelle
  • Patent number: 4872168
    Abstract: A memory array included with logic circuitry on an integrated circuit is tested by a technique that reads and writes a specified sequence of test bits into a given memory word before progressing to the next word. A checkerboard pattern of 1's and 0's is written into the physical memory locations. This provides for an improved worst-case test while allowing case of implementation for the test circuitry. The test results from a comparator circuit may be compressed to provide one (or a few) test flags indicating whether the memory passed the test, requiring a minimal number of test pads or terminals for the chip.
    Type: Grant
    Filed: October 2, 1986
    Date of Patent: October 3, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Duane R. Aadsen, Sunil K. Jain, Charles E. Stroud
  • Patent number: 4871105
    Abstract: A controlled amount of flux is applied to a circuit board (10) by first directing liquid flux through a nozzle (54) containing means for disintegrating the flux into a very fine fog of tiny flux droplets (62). The fog of flux droplets is injected into a laminar gas stream (52), thereby creating a laminar flux stream which is directed at the circuit board to coat the board with flux. As the flux spray is being directed at the circuit board, the concentration of flux solids on the board is being regulated, typically by controlling the rate of flux pumped into the nozzle.
    Type: Grant
    Filed: February 1, 1989
    Date of Patent: October 3, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: John R. Fisher, Leslie A. Guth, James A. Mahler
  • Patent number: 4872160
    Abstract: A high capacity metropolitan area network (MAN) is described. Data traffic from users is connected to data concentrators at the edge of the network, and is transmitted over fiber optic data links to a hub where the data is switched. The hub includes a plurality of data switching modules, each having a control means, and each connected to a distributed control space divisison switch. Advantageously, the data switching modules, whose inputs are connected to the concentrators, perform all checking and routing functions, while the 1024.times.1024 maximum size space division switch, whose outputs are connected to the concentrators, provides a large fan-out distribution network for reaching many concentrators from each data switching module.
    Type: Grant
    Filed: August 30, 1988
    Date of Patent: October 3, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Jayant G. Hemmady, William P. Lidinsky, Scott B. Steele, Werner Ulrich, Ronald C. Weddige
  • Patent number: 4870117
    Abstract: A waterproof cable having a filling material for filling voids in the cable which comprises a styrene-rubber diblock copolymer, a styrene-rubber-styrene triblock copolymer a paraffinic oil, a polybutene oil and a polyethylene wax. The cable is suitable for aerial use as well as underground use.
    Type: Grant
    Filed: March 3, 1988
    Date of Patent: September 26, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Alvin C. Levy
  • Patent number: 4870649
    Abstract: A reflection filter is disposed on a solid state laser so as to preferentially reflect TE or TM modes and to suppress oscillation within the resonator of the non-reflected modes. In one embodiment, the filter includes a layer having a plurality of grooves which may be straight and parallel or curved to approximate the mode shape. In another embodiment, the filter includes a polarization sensitive film, without grooves, which either absorbs or transmits the undesired mode. Specifically described is a buried heterostructure semiconductor DFB laser with such a reflection filter formed on at least one facet thereof.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: September 26, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Andrew H. Bobeck, Lloyd R. Harriott, Robert L. Hartman, Daniel R. Kaplan, George J. Przybylek, William J. Tabor
  • Patent number: 4870032
    Abstract: Certain semiconductor device structures are described in which single crystal layers of cubic Group II fluorides cover at least part of the surface of III-V semiconductor compound. The Fluoride crystal has a cubic structure and may be lattice matched or lattice mismatched to the compound semiconductor substrate depending on fluoride composition. These fluoride single crystal layers are put down by a molecular beam epitaxy procedure using certain critical substrate temperature ranges and a particular cleaning procedure.
    Type: Grant
    Filed: March 24, 1987
    Date of Patent: September 26, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Wilbur D. Johnston, Jr., Charles W. Tu
  • Patent number: 4868093
    Abstract: A hydrogen-free boron-containing membrane in tension exhibits advantageous properties for use as a mask in X-ray lithography.
    Type: Grant
    Filed: May 1, 1987
    Date of Patent: September 19, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Roland A. Levy
  • Patent number: 4867526
    Abstract: A communications cable comprising a core of at least one transmission medium and a plastic jacket includes provisions for preventing the movement of water within the cable. An impregnated tape (35) is interposed between the core and the jacket and is wrapped about the core to form a longitudinal overlapped seam. The tape comprises a substrate tape (37) which is impregnated with a superabsorbent material which upon contact with water swells and inhibits the further movement of the water. The tape and its thickness are controlled so that the thickness is minimal while the tensile strength of the tape and its porosity prior to impregnation are optimized.
    Type: Grant
    Filed: October 30, 1987
    Date of Patent: September 19, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Candido J. Arroyo
  • Patent number: 4867523
    Abstract: Disclosed is an optical fiber connector useful for high density arrays. A rotating mechanism is employed around the fiber ferrule in combination with a spring so as to engage one or more tabs on the connector sleeve. The rotating mechanism includes a serpentine type groove configuration which captures the tabs when the ferrule is pushed into the sleeve and releases the tabs when a longitudinal force is again applied to the ferrule.
    Type: Grant
    Filed: October 28, 1988
    Date of Patent: September 19, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Charles W. Scott, Jr.
  • Patent number: 4866763
    Abstract: A system for selecting multiple interexchange carriers serving telephone switches interconnecting user telephone lines. Apparatus and a method interactive with telephone users creates data base records of user selected interchange carrier resources and encodes the user created data base records into telephone switch messages. The telephone switch messages are transmitted to telephone switches to enable the telephone switches to selectively interconnect user telephone lines with ones of the interchange carrier resources in accordance with user created data base records.
    Type: Grant
    Filed: August 17, 1988
    Date of Patent: September 12, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Bret A. Cooper, William H. Havanas, Thomas R. Lanning, Mark A. Martinka
  • Patent number: 4864824
    Abstract: An actuator including a device made of thin film shape memory material mounted to a substrate. The thin film device is deformed from its original shape. Thereafter, the device is heated to restore the device to its original shape. Motion of the device occurs in the deforming and restoring steps, which is used to produce some form of work result.
    Type: Grant
    Filed: October 31, 1988
    Date of Patent: September 12, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Kaigham J. Gabriel, Mehran Mehregany, James A. Walker