Patents Represented by Attorney H. T. Brendzel
  • 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: 5506925
    Abstract: A method for reducing birefringence in a silicate waveguide structure having a waveguide core and cladding includes the step of selecting an irradiation energy that induces compaction in the cladding. The waveguide structure is then irradiated with radiation having an energy equal to the irradiation energy to induce a reduction in birefringence.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: April 9, 1996
    Assignee: AT&T Corp.
    Inventors: Benjamin I. Greene, Thomas A. Strasser, Cynthia A. Volkert
  • 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: 5172414
    Abstract: A protocol for authenticating a mobile customer unit to a service provider where signaling messages are encrypted and where voice communications can be encrypted. A service provider assigns to each mobile customer unit a unique "secret", along with other information such as a telephone number. At the pleasure of the service provider, a directive is sent to the mobile customer unit to create a shared secret datum based on the secret. The shared secret datum is created with the aid of a bit string that is sent for thatpurpose by the provider. A portion of the created shared secret datum is used for encrypting speech and the same or other portion of the created shared secret datum is used as an input to a process for creating a second encryption key. That key is employed in the mobile customer unit to encode those of the control signals generated by the mobile customer until that affect the nature of the call in progress.
    Type: Grant
    Filed: September 13, 1991
    Date of Patent: December 15, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: James A. Reeds, III, Philip A. Treventi
  • Patent number: 5159634
    Abstract: A relatively secure, self-inverting, symmetric key cryptosystem designed for efficient implementation on an 8-bit microcomputer. The cryptosystem is especially well suited use in cellular telephony. The method of encryption is comprised of three stages: 1) an autokeyed encryption, 2) the use of a one-time pad encryption where the key is derived from a portion of the message as encrypted by the first stage, and 3) a second autokeyed decryption that is the inverse of the first.
    Type: Grant
    Filed: September 13, 1991
    Date of Patent: October 27, 1992
    Assignee: AT&T Bell Laboratories
    Inventor: James A. Reeds, III
  • Patent number: 5157759
    Abstract: An enhanced text-to-speech synthesizer accepts freely generated text sequences of words and synthesizes the received sequences with proper emphasis and with properly placed pauses. In combination with other elements, the synthesizer provides for an enhanced Dual Party Relay Service where the text generated by the sound-impaired party is synthesized without an attendant's intervention. The text generated by users is made more intelligible by interpreting abbreviations, correcting errors (misspellings and "noise"), translating special terms that are used by the community of users, de-emphasizing words based on syntactic considerations and inserting pauses to enhance intelligibility.
    Type: Grant
    Filed: June 28, 1990
    Date of Patent: October 20, 1992
    Assignee: AT&T Bell Laboratories
    Inventor: Joan C. Bachenko
  • Patent number: 5155623
    Abstract: Apparatus for combining information beams by using a space variant mirror in the context of free space optical switching and computing, where light beams comprise beamlets that are focused onto surfaces to form arrays of light spots. Beam combining is achieved by positioning the space variant mirror to coincide with the plane on which the spots are focused, and to thereby allow one beam to pass through the space variant mirror without loss and another beam to be reflected off the space variant mirror, also without loss.
    Type: Grant
    Filed: October 19, 1990
    Date of Patent: October 13, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: David A. B. Miller, Michael E. Prise
  • Patent number: 5153919
    Abstract: A protocol for authenticating a cellular telephone to a service provider for the purpose of preventing the piracy of cellular services. A service provider assigns a unique "secret", along with other information such as a telephone number, to each cellular telephone when the telephone service is established with the service provider. Each base station of a service provider continuously broadcasts a periodically changing random number to all of the cellular telephones within the base station's jurisdiction. When a cellular telephone first enters the jurisdiction of a base station, it registers itself with the base station by concatenating a secret password and the most recently broadcast random number, along with other information, and passing the concatenated information to a hash function. The cellular telephone then sends the output of the hash function, along with other identifying information to the service provider.
    Type: Grant
    Filed: September 13, 1991
    Date of Patent: October 6, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: James A. Reeds, III, Philip A. Treventi
  • Patent number: 5146517
    Abstract: Transmission capabilities of optical fibers are enhanced with all-optical means for removing noise from signal pulses and for creating clean output pulses with specified characteristics. This is accomplished with a nonlinear interferometer that is designed to operate on an amplified optical signal in the manner of a threshold device. More specifically, the nonlinear interferometer is designed to have a relatively level region in its input/output transfer function in the neighborhood of the low input signal and in the neighborhood of the high input signal. Depending on the input signal characteristics, it is sometimes beneficial to design the interfereometer so that the nominal high level of the input signal falls approximately in the middle of its corresponding flat region. In another embodiment, a bandpass filter is included at the output of the interferometer to remove the excess bandwidth that is created by the preceding amplifiers and the interferometer itself.
    Type: Grant
    Filed: July 5, 1991
    Date of Patent: September 8, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: Hercules Avramopoulos, Paul M. William French, M. Christina Gabriel, Norman A. Whitaker, Jr.
  • Patent number: 5144375
    Abstract: An optical switch employs a modified sagnac arrangement that includes a sagnac loop and a coupler for injecting a signal into the loop and developing thereby two signals that travel along the loop in opposite directions. The coupler has at least one signal port that is accessible from outside the switch. In addition, a coupler is included to inject a pump signal into the loop to travel through the loop only in one direction. The loop is made of, or comprises, a material that has a controllable propagation speed. More particularly, the propagation speed in the material is a function of, for example, the intensity of the pump signal. The switch action is attained when the applied signals are in the form of pulses with pulse widths and relative positions are controlled to achieve a particular interaction. The switch action is observed by sending a pulse down a sagnac loop and observing its return.
    Type: Grant
    Filed: May 10, 1990
    Date of Patent: September 1, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: M. Christina Gabriel, Henry H. Houh, Norman A. Whitaker
  • Patent number: 5131041
    Abstract: A multi-stage, alternate routing switching network is enhanced with a switch architecture that is able to detect and mask all single faults. The switch employs a controller that develops dual rail control signals. In one embodiment, the controller is made up of two controllers that receive the same inputs but generate complementary outputs. The complementary outputs form the dual rail signals that control the multiplexers that are interposed between the inputs and the outputs of the switch. The dual rail control of the signal routing within the switch allow for effective detection of all signal faults in the signal routing means. Inclusion of totally self checking circuits at the switch outputs as well as inputs enables users to readily isolate a fault and identify its source.
    Type: Grant
    Filed: November 30, 1989
    Date of Patent: July 14, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: Beat Brunner, Vijay P. Kumar
  • Patent number: 5128756
    Abstract: Graceful degradation for digitally encoded HDTV signals is achieved by appropriately coding the image to provide a controllable degradation of chosen image characteristics, such as temporal degradation, spatial degradation, and dynamic range degradation. In the temporal degradation approach of this invention, the resolution of movement suffers when noise is introduced. In the spatial degradation approach, the spatial resolution of the image is sacrificed. In the range degradation approach, the dynamic range of the signals is sacrificed. The graceful degradation is achieved by dividing the transmitted signal into two or more parts, such as parts A, B and C. Part A is given the heaviest error-correcting code; part B is given a "medium" error correcting code; and part C the is given the least powerful error correcting code (or perhaps none at all). A receiver that is close to the transmitter most likely receives parts A, B and C.
    Type: Grant
    Filed: December 11, 1990
    Date of Patent: July 7, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: James D. Johnston, Scott C. Knauer, Kim N. Matthews, Arun N. Netravali, Eric D. Petajan, Robert J. Safranek, Peter H. Westerink
  • Patent number: 5107452
    Abstract: Method and apparatus for efficiently performing preselected computations on data that, in part, changes seldomly. A recognition that a portion of the data does not change leads to substantial improvements in computation speed through apparatus that tailors the program that executes the computation to the data itself. In the context of multiplication of a matrix that varies seldomly by a vector that changes more often, this is accomplished by reordering the elemental operations so that accesses to memory are reduced, both for purposes of reading information and writing back to memory, and developing code that reflects the required sequence of operations.
    Type: Grant
    Filed: September 4, 1987
    Date of Patent: April 21, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: Narendra K. Karmarkar, Kajamalai G. Ramakrishnan
  • Patent number: 5093803
    Abstract: A circuit for realizing controllable analog weights as used, for example, in template matching circuits. Analog weights are obtained by storing charge on two primary capacitors and by controlling the potential difference between the two primary capacitors. The control of charge on the two capacitors is effected with a bridging connection between the two primary capacitors. In one embodiment, the bridging connection contains two switches and an MOS transistor.
    Type: Grant
    Filed: December 22, 1988
    Date of Patent: March 3, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: Richard E. Howard, Daniel B. Schwartz
  • Patent number: 5093920
    Abstract: An arrangement for implementing graph operations, generally, and circuit simulations in particular employing a plurality of substantially identical high speed special purpose processing elements (PE) that are flexibly interconnected through a switch to form a cluster. In addition to the processing element (PE) being programmable, the interconnection switch permits dynamically altered routing of signals between the processing elements. The processing elements include a queue unit which permits high speed asynchronous communication between the elements. Additional advantage is attained with a hierarchical arrangement where a plurality of clusters are interconnected in an n-cube arrangement, and all of the clusters communicate with a host computer.
    Type: Grant
    Filed: September 15, 1989
    Date of Patent: March 3, 1992
    Assignee: AT&T Bell Laboratories
    Inventors: Prathima Agrawal, William J. Dally, Anjur S. Krishnakumar
  • Patent number: 5043808
    Abstract: A high definition television system that is characterized by low transmission bandwidth is achieved by in a manner removing much of the redundancies in the signal, efficiently encoding the remaining signals, and transmitting the encoded signal in a manner that is most compatible with the applicable standards. Specifically, the television signal is encoded by developing motion vectors that describe the best motion estimate of the image to be transmitted, by developing motion estimation error signals, by encoding these error signals within the same bandwidth as occupied by standard NTSC signals and by transmitting the encoded error signals during periods that correspond to the active scan intervals of the NTSC TV signal. The motion vectors themselves, together with video and control signals, are transmitted during the NTSC retrace period.
    Type: Grant
    Filed: March 19, 1990
    Date of Patent: August 27, 1991
    Assignee: AT&T Bell Laboratories
    Inventors: Scott C. Knauer, Kim N. Matthews, Arun N. Netravali, Eric D. Petajan, Robert J. Safranek
  • Patent number: 5040062
    Abstract: A high definition television system that is characterized by low transmission bandwidth is achieved by removing redundancies in the signal and encoding the remaining signals. In the encoding, a portion of the signals to be transmitted is created in the form of an analog signal or a concatenated plurality of pulse amplitude coded samples (A-signal), and another portion of the signals to be transmitted is created in digital form (D-signal). The D-signal is consigned to a specified portion of the transmitted signal, leaving the remainder of the transmission capacity for the A-signal. When the normally created digital signals do not fully occupy the digital portion, enhanced operation results when selected ones of the analog signals or samples are excised from the A-signal, encoded digitally, and added to the D-signal. The excising of those signals leaves room in A-signal portion to include additional analog signals. This leads to an overall better image reproduction at the receiver.
    Type: Grant
    Filed: March 19, 1990
    Date of Patent: August 13, 1991
    Assignee: AT&T Bell Laboratories
    Inventors: Scott C. Knauer, Kim N. Matthews, Arun N. Netravali, Eric D. Petajan, Robert J. Safranek, Peter H. Westerink
  • Patent number: 5018129
    Abstract: A method for realizing, and a structure for implementing a switching network employing 2.times.2 switches. The network is dilated in that none of the 2.times.2 switches concurrently carry an active signal. The method for realizing such a network alters a given non-dilated network by replacing each 2.times.2 switch in the non-dilated network with a dual rail switch having a pair of 2.times.2 interconnected switches, and by replacing each link in the non-dilated network with a pair links. The final output of the dilated network is obtained by adding a combiner final stage which combines the pairs of signals to form output signals that parallel the output signals of the given non-dilated network.
    Type: Grant
    Filed: March 9, 1989
    Date of Patent: May 21, 1991
    Assignee: AT&T Bell Laboratories
    Inventors: Arun N. Netravali, Krishnan Padmanabhan
  • Patent number: 5007102
    Abstract: A transform approach to image coding where pixels are coded in the order prescribed by a predetermined "List". The code for each pixel is developed by computing a prediction for the pixel based on the known pixel values in the neighborhood of the pixel and subtracting this prediction from the true value of the pixel. This results in a sequence of predominantly non-zero valued pixel prediction errors at the beginning of the encoding process (of each block), and predominantly zero valued pixel prediction errors towards the end of the encoding process. Enhancements to this approach include adaptive encoding, where pixel sequences having expected zero prediction errors are not encoded, and run length encoding of the signals to be transmitted or stored for augmenting the encoding process.
    Type: Grant
    Filed: May 3, 1989
    Date of Patent: April 9, 1991
    Assignee: AT&T Bell Laboratories
    Inventor: Barry G. Haskell