Patents Assigned to Bell Communications Research, Inc.
  • Patent number: 5636208
    Abstract: An improved technique for simultaneously performing bit synchronization and error detection of received digital data bursts in a time division multiplexed/time division multiple access (TDM/TDMA) system, such as that used in conjunction with low power portable digital telephony. With the improved technique both bit synchronization and error detection are performed simultaneously to thereby reduce latency in the transceiver. Since round-trip delay is reduced, echo suppression techniques may not be needed.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: June 3, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Li-Fung Chang, Robert A. Ziegler
  • Patent number: 5633928
    Abstract: A key escrow technique is disclosed which permits cryptographic limits on wiretapping warrants. Specifically, time limits on wiretaps may be enforced. In addition, the wiretapper is targeted to a specific party or specific pairs of parties communicating in a network.
    Type: Grant
    Filed: March 10, 1995
    Date of Patent: May 27, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Arjen K. Lenstra, Peter M. Winkler, Yacov Yacobi
  • Patent number: 5630993
    Abstract: A method of making a single phase, layered lithiated transition metal oxide material which comprises reacting a transition metal hydroxide with a lithium source in a basic solution in the presence of water at a pressure greater than atmospheric and at a temperature of from about 50.degree. C. to 150.degree. C.
    Type: Grant
    Filed: July 5, 1995
    Date of Patent: May 20, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Glenn G. Amatucci, Jean-Marie Tarascon
  • Patent number: 5629992
    Abstract: An optical filter, such as a wavelength-division multiplexer, demultiplexer, or optical router, in which several single-mode waveguides are coupled to the sides of an optical interaction region containing a wavelength dispersive element that collects light from one or more input waveguides inputting light to the interaction region and disperses it according to wavelength to one or more output waveguides outputting wavelength-separated light. According to the invention, a multi-moded waveguide is interposed between one or more of the single-moded waveguides and the optical interaction region. It has a predetermined length to create at one end a multiply peaked image of a singly peaked profile presented to it at the other end, thus being a multi-mode interference (MMI) filter that presents a flatter filter profile at the interface between the MMI and the optical interaction region and affords reduced filter sensitivity to wavelength drift of an optical signal.
    Type: Grant
    Filed: September 14, 1995
    Date of Patent: May 13, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Martin R. Amersfoort, Julian B. D. Soole
  • Patent number: 5621768
    Abstract: A generalized noise canceler for canceling noise in a channel having noise composed of correlated noise components. The noise canceler is realized with a finite number of cascade networks, each network being composed of an inner product filter is series with another filter wherein both filters have characteristics determined from a eigenvector equations expressed in terms of the channel operator and noise operator.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: April 15, 1997
    Assignee: Bell Communications Research, Inc.
    Inventor: Joseph W. Lechleider
  • Patent number: 5615267
    Abstract: A method for adaptively switching between the WS and S authentication schemes is based on the customer's usage. A first preferred embodiment provides a 2n-1 state automaton (where n>1), which switches from the WS Scheme to the S Scheme when the automaton passes from state n-1 to state n, and vice versa. At each new registration, the automaton increases one state if more than 1 call was made (i.e., incoming or outgoing) during the cycle; decreases one state if no calls were made during the cycle; and remains the same if 1 call was made during the cycle. The value of n is preferably determined by the PSP based on customer usage. A second preferred embodiment begins each new cycle with the WS Scheme, and will switch to the S Scheme if a call is made during the registration.
    Type: Grant
    Filed: July 17, 1995
    Date of Patent: March 25, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Jason Y. Lin, Seshadri Mohan, Howard Sherry, Nelson R. Sollenberger
  • Patent number: 5614927
    Abstract: A system and method are disclosed for protecting a database against deduction of confidential attribute values therein. A memory 160 is provided for storing the database and a processor 155 is provided for processing the database. Using the processor, the database is electronically partitioning into public attributes, containing nonconfidential attribute values, and private attributes, containing private attribute values. The processor is then used to electronically process the private attribute values to reduce any high correlation between public attribute values and private attribute values. Specifically, the processor can partition the database into safe tuples and unsafe tuples, which unsafe tuples have highly correlative public attribute values. The processor can then selectively combine the public attribute values of the tuples to camouflage such tuples from deduction of their private attribute values beyond a threshold level of uncertainty or remove such tuples from the database.
    Type: Grant
    Filed: June 12, 1995
    Date of Patent: March 25, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Warren S. Gifford, Nancy D. Griffeth, James E. Katz
  • Patent number: 5615286
    Abstract: The number of calculations to determine the most likely path is reduced by eliminating a number of paths that are impossible to provide an optimal result. How to eliminate these non-optimal paths, thus greatly reducing the number of calculations performed by a signal processor. The determination of the probability score of the best path to state s at time t may be found as follows. First, transition probabilities to state s are sorted in order of descending probability. Second, the k highest probability scores at time t-1 are identified. Third, the highest transition probability associated with the k highest probability scores at t-1 is identified and designated maxrank. Fourth, the k highest probability scores at t-1 are multiplied with their associated transition probabilities with the highest product being designated maxvalue. Fifth, all transition probabilities higher than maxrank are multiplied with their associated probability scores at t-1.
    Type: Grant
    Filed: May 5, 1995
    Date of Patent: March 25, 1997
    Assignee: Bell Communications Research, Inc.
    Inventor: Sarvar M. Patel
  • Patent number: 5615351
    Abstract: A method and system for providing a dynamic key in usage records for correlating the usage data records created in a distributed computer or telecommunications network. The dynamic key is a composite structure which captures and reflects the control flow between the service components. The method as been implemented in a software object that would be resident in each component of a distributed telecommunications system. Specifically, the keys created are dynamic key comprised of at least two fields. The first field is a unique identifier that identifies the session. The second field is number that identifies the position within the sequence of invoked components that the present component was invoked. This dynamic key is forwarded to the next component and is used as the unique identifier and becomes the first field in the next component's key. These keys allow for correlating usage data records from disparate sources to accomplish such activities as billing and/or fraud detection.
    Type: Grant
    Filed: July 7, 1995
    Date of Patent: March 25, 1997
    Assignee: Bell Communications Research, Inc.
    Inventor: Shoshana K. Loeb
  • Patent number: 5613032
    Abstract: A system for recording and playing back multimedia events includes recording sources, a preprocessor, a delivery processor, and user control units. The recording sources each captures a continuous temporal record or track of the multimedia event and transmits the captured track to the source preprocessor where tracks are coded into digital blocks and digitized blocks of tracks received simultaneously are time stamped with the same relative time, and therefore synchronized in time. Tracks of the multimedia event are also compressed and preprocessed to generate other representations of the multimedia event, which further assist users in searching through the multimedia event. The delivery processor services users' requests for multimedia events and delivers events to requesting users according to users' interactive commands.
    Type: Grant
    Filed: September 2, 1994
    Date of Patent: March 18, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Gil C. Cruz, Steven L. Rohall, Jonathan Rosenberg, Lanny S. Smoot
  • Patent number: 5612968
    Abstract: A semiconductor integrated-circuit laser array including redundant lasers that is particularly useful in a wavelength-division multiplexed communication system requiring N channels regularly spaced in wavelength. According to a first aspect of the invention, a plurality of lasers are designed to operate at the same wavelength so that a single inoperative laser will not prevent the laser array from operating. Further, sets of lasers are chosen which have wavelength spacings closest to the design spacing. According to a second aspect of the invention, the laser array includes lasers with spacings in between the design wavelengths. Thereby, if all the lasers systematically vary in wavelength, a set of lasers can be selected that will operate not far from their nominal operating wavelength.
    Type: Grant
    Filed: April 20, 1995
    Date of Patent: March 18, 1997
    Assignee: Bell Communications Research, Inc.
    Inventor: Chung-en Zah
  • Patent number: 5612734
    Abstract: Apparatus for establishing eye contact between communicating parties during video conferencing comprises mirrors, a directionally transmissive layer, such as a louver assembly, and a camera are positioned, with respect to one another such that more intimate communication is realized between the parties without substantially reducing the transmissivity of the apparatus. Internal to this apparatus, the louver assembly is located in front of the terminal screen and passes an image of the distant party radiated from the terminal screen which is substantially parallel to microlouvers of the louver assembly. A first mirror, which is partially silvered, reflects the image of the local party and transmits the image of the distant party that is radiated from the terminal screen and passed by the louver assembly. The reflected image of the local party is directed toward a second mirror located below the first mirror.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: March 18, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Terence J. Nelson, Barry R. Vaning
  • Patent number: 5608801
    Abstract: Methods and circuitry for generating a cryptographic hash function using a strong pseudo-random generator along with the input data to create high quality pseudo-random keys as indices to pseudo-random functions, as well as a pseudo-random function from 2n bits to 2n bits given a pseudo-random function from n bits to n bits.
    Type: Grant
    Filed: November 16, 1995
    Date of Patent: March 4, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: William A. Aiello, Ramarathnam Venkatesan
  • Patent number: 5608789
    Abstract: In a telecommunication network, a method of creating, in response to inputs from an operator, a user defined call processing node for a call processing record. The call processing record contains logically related nodes and branches. Initially, the operator instructs the processor that he or she wishes to construct a user defined call processing node. The processor then presents to the operator a display screen in which to construct the user defined call processing node and presents the operator with a list of predefined nodes. From this list, the operator selects predefined nodes and arranges them into an underlying representation of call processing procedures. Once this is completed, the processor enables the underlying representation of call processing procedures as a single node for use in creating call processing records.
    Type: Grant
    Filed: April 3, 1996
    Date of Patent: March 4, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Gregory M. Fisher, Kathleen D. Cebulka, Susan K. Man, Zaher A. Nazif, Lori J. Vinciguerra
  • Patent number: 5607485
    Abstract: A flexible polymeric film useful as an interelectrode separator or electrolyte member in electrolytic devices, such as rechargeable batteries, comprises a copolymer of vinylidene fluoride with 8 to 25% hexafluoropropylene. The film may be cast or formed as a self-supporting layer retaining about 20% to 70% of a high-boiling solvent plasticizer or plasticizer mixture comprising such solvents as ethylene carbonate, propylene carbonate, dimethyl carbonate, and dibutyl phthalate. The film may be used in such form or after extracting of the retained plasticizer with a film-inert low-boiling solvent to provide a separator member into which a solution of electrolytic salt is subsequently imbibed to displace retained plasticizer or replace plasticizer previously extracted from the polymeric matrix.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: March 4, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Antoni S. Gozdz, Caroline N. Schmutz, Jean-Marie Tarascon, Paul C. Warren
  • Patent number: 5606596
    Abstract: Method and system for locating nomadic users in a personal communication services (PCS) system by utilizing two strategies for locating such users and a per-user criterion for determining which, if any, of the two strategies should be used. The method and system augment basic two-level strategies for locating users specified in IS-41 and GSM standards of PCS systems. One strategy utilizes forwarding pointers and the other strategy utilizes per-user location caching. One per-user criterion is a call-to-mobility ratio (CMR) which is the ratio of the average rate at which a user receives calls to the average rate at which the user moves. A variation of this criterion is the local CMR (LCMR) which is the ratio of the average rate at which a user receives calls from a given registration area, to the average rate at which the user moves. The method and system reduce the average time and overhead required to locate and deliver information to such nomadic users.
    Type: Grant
    Filed: May 5, 1995
    Date of Patent: February 25, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Ravi K. Jain, Charles N. Lo, Seshadri Mohan
  • Patent number: 5600643
    Abstract: A Broadband Intelligent Network employs an ATM fast-packet switch to route signaling cells from a calling party to a switch port directly connected to a network controller. The signaling cells carry a service request for download of a program module or data from a network resource unit to the calling party, or for download of a program module or data from the calling party apparatus to a network host resource unit, or for service circuit service to the calling party or in a connection path between the calling party and a called party, or for a message broadcast. The network controller responds to the information in the signaling cells and establishes the necessary switched virtual connections in the ATM switch to provide the requested services. A service creation program may be downloaded to the customer from the network, and used by the customer to create a new service script which is subsequently downloaded to the network for execution.
    Type: Grant
    Filed: September 23, 1993
    Date of Patent: February 4, 1997
    Assignee: Bell Communications Research, Inc.
    Inventor: Richard B. Robrock, II
  • Patent number: 5600820
    Abstract: A method and system are provided for managing memory to reassemble data packets received from different virtual channels in an ATM network. The method and system recognizes that both reliable and best effort traffic must be supported by a network interface. The system makes use of a virtual First-In-First-Out (FIFO) concept that partitions RAM memory space into multiple FIFO queues. The virtual FIFOs can have different sizes, and can be allocated to connections depending on quality of service requirements. A dedicated embedded controller 721 to provide flexibility is used in the system, as well as Content Addressable Memory (CAM) devices 723,724, and external logic. The method and system can also be applied at ATM transmitters in the implementation of congestion control algorithms.
    Type: Grant
    Filed: December 1, 1993
    Date of Patent: February 4, 1997
    Assignee: Bell Communications Research, Inc.
    Inventor: Cesar A. Johnston
  • Patent number: 5594911
    Abstract: A system and method for preprocessing and delivering multimedia presentations to customers such that delays due to interactive response time is virtually eliminated include a preprocessor, mass storage, a delivery processor, a distribution network, and a plurality of presentation processors. The preprocessor receives as inputs an original multimedia presentation and parameters characterizing other system components, which parameters include the round trip latency between the delivery processor and a presentation processor, and generates a preprocessed multimedia presentation including a delivery schedule in the form of a labelled, directed graph.
    Type: Grant
    Filed: July 13, 1994
    Date of Patent: January 14, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Gil C. Cruz, Ralph D. Hill, Thomas H. Judd, Darren H. New, Jonathan Rosenberg
  • Patent number: 5592672
    Abstract: A service control point having multiple independent control processor and multiple front end communication processors incorporates a deterministic rule message distribution process for balancing the traffic load among the front end processors from all the independent control processors. The deterministic rule method is applied independently in each control processor and queues all outgoing messages in one of three queues; those that must be transmitted on Linkset-0, those that must be transmitted on Linkset-1, and those that can be transmitted on either linkset. Our message distribution process keeps all messages in queue until message number or timer threshold is reached. The traffic is routed to a front end processor such that the resulting distribution is closest to the expected distribution.
    Type: Grant
    Filed: January 18, 1996
    Date of Patent: January 7, 1997
    Assignee: Bell Communications Research, Inc.
    Inventors: Kalwant S. Grewal, Jagdish A. Patel, Tzyh-Jong Wang