Patents Represented by Attorney E. Weiss
  • Patent number: 5509074
    Abstract: A method for protecting electronically published documents involves operating a computer system and network for electronic publication of documents, and includes the steps of receiving requests for documents from users having computers with display devices or printers, including with the requests unique user identification for each of the user; authenticating the requests with a copyright server; using the copyright server to direct a document server to act upon proper authentication of each request; using the document server to create uniquely encoded, compressed and encrypted documents for each authenticated request, where the documents have unique encoding corresponding to each of the users, and forwarding the documents to each authenticated request user through the network to corresponding agents of each authenticated request user, with each of the agents being selected from display agents and printer agents; and decrypting and uncompressing the documents at each of the agents and making the documents ava
    Type: Grant
    Filed: January 27, 1994
    Date of Patent: April 16, 1996
    Assignee: AT&T Corp.
    Inventors: Abhijit K. Choudhury, Nicholas F. Maxemchuk, Sanjoy Paul, Henning G. Schulzrinne
  • Patent number: 5506890
    Abstract: A method and system for industry and group-specific calling within a telecommunication system. The method of the present invention includes the steps of receiving, in a carrier network, a call initiated by dialing a group number from a caller terminal; accessing a database in the carrier network to determine an announcement corresponding to the group number; providing the announcement to the caller terminal to prompt a caller to select one of the group members associated with the dialed group number; interpreting a selection command received from the caller to determine a member number of a selected group member; establishing a connection between the network and a member terminal corresponding to the selected member number; and connecting the call from the caller terminal to the selected member terminal. The caller may terminate the connection between the network and the member terminal, and select a connection to other group members, without dialing any additional numbers.
    Type: Grant
    Filed: November 16, 1993
    Date of Patent: April 9, 1996
    Assignee: AT&T Corp.
    Inventors: Alok K. Gupta, Ajay Jain, Shri P. Jain, Paramdeep S. Sahni
  • Patent number: 5495521
    Abstract: Access of a user to a resource, such as a telecommunications network, includes storing, in a first call data base, a first set of attributes concerning an ongoing call from a caller. A second call data base stores a second set of attributes concerning the history of prior calls made by the caller. A rules data base stores rules concerning attributes for determining whether to disconnect the call, block future calls, or take other action. A determination is made whether data in at least one of the call data bases matches the rules in the rules data base. The call is then disconnected, the next call blocked, or other action is taken, in response to a match between data the call data bases and data in the rules data base. Preferably, the second call data base is updated in response to matches with the rules data base.
    Type: Grant
    Filed: November 12, 1993
    Date of Patent: February 27, 1996
    Assignee: AT&T Corp.
    Inventor: Hemmige V. Rangachar
  • Patent number: 5235658
    Abstract: This invention is directed toward joining an optical fiber to a waveguide on a silicon or silica substrate. In a preferred embodiment, a discontinuity such as a notch is provided in the substrate along each side of a waveguide. The notches, which extend back from the end of each waveguide form air gaps between the ends of adjacent waveguides. Now, when an optical fiber is butt coupled to a waveguide on a substrate with adhesive, the notches at either side of the waveguides prevent adhesive from flowing along the edge of the substrate and onto the end of an adjacent waveguide. In addition, the adhesive flows around and encapsulates the substrate projections defined by the notches along the ends of the waveguide to provide a sturdy butt connection.
    Type: Grant
    Filed: March 30, 1992
    Date of Patent: August 10, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Corrado Dragone, Herman M. Presby
  • Patent number: 5229876
    Abstract: In this invention telemetry information is transmitted in an optical fiber communication system by providing an amplifier pump with excess power beyond that necessary to pump the amplifier. The excess power is not used to pump the amplifier but is rather used to transmit the telemetry information. In a specific embodiment, an optical communication system including a doped optical fiber amplifier such as, for example, an erbium doped amplifier, is provided with an amplifier pump which operates at approximately 1.48 .mu.m. The amplifier pump is provided with excess power so as to transmit telemetry information. In a specific embodiment, the telemetry signal can be detected with a low cost photodetector at a subsequent station.
    Type: Grant
    Filed: March 26, 1990
    Date of Patent: July 20, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: M. T. Fatehi, Nils A. Olsson
  • Patent number: 5225922
    Abstract: Increasing the capacity of an existing lightwave transmission system can be accomplished by either increasing the bit rate or adding wavelength-multiplexed channels. Recent advances in erbium-doped fiber amplifier technology make the wavelength division multiplexed option particularly attractive. Unfortunately, because of nonuniform wavelength-dependent gain profile and saturation characteristic of erbium-doped fiber amplifiers, each channel of a wavelength-multiplexed system will experience a different optical gain which, in turn, can result in an excessive bit-error-rate performance in some channels. This invention is directed toward processing apparatus which selectively equalizes the optical gain or the optical signal-to-noise ratios of the channels of a wavelength-multiplexed optical transmission system. The output powers and the signal-to-noise ratios are selectively equalized by adjusting the optical input signal powers.
    Type: Grant
    Filed: November 21, 1991
    Date of Patent: July 6, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Andrew R. Chraplyvy, Jonathan A. Nagel, Robert W. Tkach
  • Patent number: 5223705
    Abstract: In an embodiment for obtaining accurate noise figure measurements for any degree of saturation of an optical amplifier, a polarizer is located at the output of the optical amplifier. The amplified spontaneous noise (ASE) produced by an optical amplifier is not polarized, whereas the amplified signal has a well defined state of polarization which is preferably linear. If the amplified signal is not linearly polarized, it can be rendered linearly polarized in one direction by means of a polarization controller located downstream of the polarizer. By setting the polarizer to have its state of polarization orthogonal to that of the linearly polarized amplified signal, the spectral density of the ASE from the polarizer can be measured without associated distortion due to the signal. By sequentially adjusting the polarization controller to minimize and then maximize the signal which it passes, sequential measurements of the ASE spectral density and gain of the optical amplifier can be obtained.
    Type: Grant
    Filed: August 12, 1992
    Date of Patent: June 29, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Jennifer Aspell, Neal S. Bergano, Bruce M. Nyman, Richard G. Smart, James W. Sulhoff, John L. Zyskind
  • Patent number: 5213748
    Abstract: In a pre-molded package assembly, a thermoplastic ring molded onto a leadframe must maintain lead coplanarity. In this invention a plastic member of liquid crystal polmar is molded onto the leads of a metal leadframe. The plastic member is a thermoplastic anisotropic material which, when formed, has a flow direction which is in the long dimension of the plastic member and a transverse direction which is in the short dimension of the plastic member. Dam members on the leadframe help contain the plastic molding compound within the mold cavity during the molding process. A puddle gate prevents the formation of a weld line in the plastic member. Upon completion of the molding process, the dam members are excised from the leadframe to provide discrete leads.
    Type: Grant
    Filed: June 27, 1991
    Date of Patent: May 25, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Ranjit Biswas, Michael A. Zimmerman
  • Patent number: 5212584
    Abstract: A tunable etalon filter is formed by placing mirrors on either side of a spacer of a material which has a relatively large rate of change of refractive index with temperature, and coupling the filter to a thermoelectric cooler to control the temperature of the spacer and, therefore, the index of refraction of the spacer. More specifically, the spacer can be a silicon wafer, or a wafer of zinc sulfide or zinc selenide. The mirrors can be formed of quarter wavelength layer pairs of dielectric coatings of high and low refractive index material. The thermoelectric cooler, which can be coupled to a heat sink, controls the temperature of the spacer by either heating or cooling the spacer. In operation the filter is coarse tuned by adjusting its angle relative to the angle of a received optical signal. It is then fine tuned to the signal by adjusting the temperature of the spacer.
    Type: Grant
    Filed: April 29, 1992
    Date of Patent: May 18, 1993
    Assignee: AT&T Bell Laboratories
    Inventor: Yun C. Chung
  • Patent number: 5208885
    Abstract: This invention is directed toward joining, with glass, a waveguide supported by a substrate to an optical fiber. In a preferred embodiment, a glass material which melts at a temperature that is lower than the temperature to which the waveguide can be safely heated is applied to either the optical fiber and/or the waveguide. The glass material is then heated to cause it to connect the optical fiber to the waveguide. A feature of the invention is the presence of heat breaks in the substrate upon which the waveguide resides to thermally isolate the end of each waveguide and the underlying substrate from adjacent waveguides and the portions of the substrate which underlie said adjacent waveguides. The heat breaks restrict heat from being conducted along the end of the substrate from one waveguide region to adjacent waveguide regions when heat is being applied to make a connection.
    Type: Grant
    Filed: February 27, 1992
    Date of Patent: May 4, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Corrado Dragone, Herman M. Presby
  • Patent number: 5181134
    Abstract: This invention relates to an optical cross-connect switch which is substantially loss-less and is transparent to signal bit rate, format and modulation scheme. The optical cross-connect switch can be comprised of at least two stages of chips coupled in tandem via optical fibers. Each chip can be of lithium niobate having a plurality of digital switch elements or directional couplers which, by means of an electric field, can selectively switch optical energy from one waveguide to another. The chips are coupled together via optical fiber amplifiers and the optical fiber amplifiers are pumped by optical pumps, e.g., 1.48 .mu.m CW, laser pumps, coupled to appropriate nodes within either one or both of the chips. In operation, the pump energy is switched through the chips along with the optical data signals to pump only those optical fiber amplifiers which are in the optical data signal path.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: January 19, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Mohammad T. Fatehi, Nattu V. Srinivasan
  • Patent number: 5173957
    Abstract: Currently laser diode pump redundancy for an optical fiber amplifier is obtained by selectively connecting one of two diode pumps to an optical amplifier via an optical switch. When the diode laser pump which is connected to the amplifier becomes defective, the optical switch is activated, either remotely or automatically, and the good laser diode is substituted for the defective laser diode pump. In another arrangement, two laser diodes are coupled to an optical fiber amplifier via a polarization-dependent optical coupler. In each instance, a second laser diode is required to provide pump redundancy for an optical fiber amplifier.In this invention, at least, two laser diodes are coupled via a 3 dB optical coupler to supply pump power to each of the two optical fiber amplifiers simultaneously. If one of the laser diode pumps fails, the other laser diode pump provides pump power to each of the optical fiber amplifiers.
    Type: Grant
    Filed: September 12, 1991
    Date of Patent: December 22, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: Neal S. Bergano, Richard F. Druckenmiller, Franklin W. Kerfoot, III, Patrick R. Trischitta
  • Patent number: 5172213
    Abstract: A major issue in the semiconductor industry is the amount of power that a silicon device dissipates. As the density of silicon integrated circuits increases with improvements in wafer processing, so does the amount of heat which must be evacuated. If the power of the silicon devices exceeds one watt, the plastic encapsulating material normally yields to the more expensive ceramic or metal packages which can dissipate thermal energy more efficiently. The conventional molded package is a silicon device such as a chip mounted onto a copper paddle which spreads the heat radially in the material and is bonded to leads via thin wires. The three major paths for the heat to escape are by conduction through the molding compound to the surface of the package where removal is by convection, and by conduction from the silicon device through the thin wires to the leads of the package and then to the printed circuit board, and by a heat conducting paddle which radially spreads the heat through the molding compound.
    Type: Grant
    Filed: May 23, 1991
    Date of Patent: December 15, 1992
    Assignee: AT&T Bell Laboratories
    Inventor: Michael A. Zimmerman
  • Patent number: 5170455
    Abstract: This invention is an optical connective device which can have a two-dimensional array of optical fibers. The device can be comprised of a single piece of light conducting material such as glass, plastic or the like shaped to have a slab support member having pillars which project outward from opposing surfaces. The pillars on one of the opposing surfaces are optically aligned with corresponding pillars on the other opposing surface. The length of a pillar can be as small as its diameter. The ends of the pillars can be flat or curved to form a lens and each pillar can be accurately located to an arbitary position. The optical connective device can be sandwiched between chips to provide an integrated circuit chip-to-chip connective device for a stack of two or more chips.
    Type: Grant
    Filed: October 30, 1991
    Date of Patent: December 8, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: Keith W. Goossen, James A. Walker
  • Patent number: 5157744
    Abstract: It has been determined that optical fibers possess a small amount of nonlinearity and, therefore, they are not exactly linear waveguides. This small amount of nonlinearity enables certain special pulse shapes to establish themselves and travel long distances without changing shape. These special pulse shapes are called solitons. This invention relates to a device for generating solitons by amplitude modulating an optical signal with separate in-phase electrical signals of different harmonically related frequencies. Specifically, an amplitude modulator such as a Y junction Mach-Zehnder interferometer has multiple sets of distributed electrodes. The interferometer has a set of electrodes for each electrical signal of a specific frequency. Thus, if three separate signals of harmonically related frequencies are used to amplitude modulate an optical signal, then the interferometer has three sets of electrodes located between the Y junctions of the Mach-Zehnder interferometer.
    Type: Grant
    Filed: December 16, 1991
    Date of Patent: October 20, 1992
    Assignee: AT&T Bell Laboratories
    Inventor: Steven K. Korotky
  • Patent number: 5155780
    Abstract: This invention relates to an optical limiting amplifier which provides an optical output signal of substantially constant power for an optical input signal of varying power which is simple to construct and economical to build. In this invention, an optical signal whose power can fluctuate over a wide range is split into two signals. The first signal is applied to an optical fiber amplifier in the forward feed direction. The second signal is passed through a saturable absorber and then applied to the optical fiber amplifier in the backward feed direction. The signal from the saturable absorber varies at a rate which is greater than the rate that the signal to the saturable absorber varies. Thus, as the signal to the saturable absorber increases, the signal from the saturable absorber will increase at a greater rate; and, as the signal to the saturable absorber decreases, the signal from the saturable absorber will decrease at a greater rate.
    Type: Grant
    Filed: January 27, 1992
    Date of Patent: October 13, 1992
    Assignee: AT&T Bell Laboratories
    Inventor: Martin Zirngibl
  • Patent number: 5138633
    Abstract: This invention is a timing recovery arrangement which adaptively retimes and regenerates a received stream of data pulse signals. The received stream of data pulse signals are selectively simultaneously sampled at two or more locations for the presence or absence of a data pulse signal. A signal representative of the detection of a pulse signal is generated for each location. The signals for the locations sampled are combined to generate a control signal which is used to selectively controllably change the locations where the samples are taken. Changing the locations where the samples are taken continues until the signal for the first location sampled is substantially equal to the signal for the second location sampled. In accordance with an embodiment of the invention, the control signals obtained, when two locations sampled, are sampled are generated by integrating the signals from the respective locations sampled to generate a first control signal and a second control signal.
    Type: Grant
    Filed: November 19, 1990
    Date of Patent: August 11, 1992
    Assignee: AT&T Bell Laboratories
    Inventor: John A. Cortese
  • Patent number: 5128800
    Abstract: An optical fiber amplifier has a lossy nonlinear medium connected between its input port and its output port. The resultant optical feedback loop permits remote gain switching of the optical amplifier.
    Type: Grant
    Filed: June 19, 1991
    Date of Patent: July 7, 1992
    Assignee: AT&T Bell Laboratories
    Inventor: Martin Zirngibl
  • Patent number: 5127081
    Abstract: An optical branching waveguide having low radiative loss and low back-reflectivity is described. By employing between the branches a region having a gradual decrease in effective refractive index along the direction of optical propagation, the deleterious effect of wedge tip truncation can be reduced. According to the teachings of the invention, this may be accomplished by gradually decreasing the thickness of the optical material along the axis of optical propagation and planarizing the region with an optical material having a lower refractive index than the underlying optical material.
    Type: Grant
    Filed: August 3, 1990
    Date of Patent: June 30, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: Uziel Koren, Kang-Yih Liou
  • Patent number: 5105438
    Abstract: This invention is a method of remotely accessing an Intelligent Network Channel Terminating Equipment device to expedite the testing and servicing of telecommunications circuits.Intelligent Network Channel Terminating Equipment devices from different manufacturers have different operating characteristics. Therefore, prior to remotely accessing and operating an Intelligent Network Channel Terminating Equipment device in a telecommunication circuit from a remote location, the operating characteristics of the device must be determined. At the heart of the invention is our recognition that Intelligent Network Channel Terminating Equipment can be categorized according to their operational characteristics and that the type of Intelligent Network Channel Terminating equipment device present at a remote location can be identified from its response to signals which are sent to the Intelligent Network Channel Terminating Equipment device.
    Type: Grant
    Filed: December 10, 1990
    Date of Patent: April 14, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: John M. Ackroff, James C. Domangue