Patents by Inventor David P. Schenkel

David P. Schenkel has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20160100315
    Abstract: A rogue access point in a wireless local-area network can be disabled by an authorized access point wirelessly transmitting a layer-2 broadcast packet. If a rogue access point receives this broadcast packet, it will forward a copy to the switch to which it is connected. The switch then shuts down the port on which it received the forwarded copy of the broadcast packet.
    Type: Application
    Filed: December 14, 2015
    Publication date: April 7, 2016
    Inventors: David P. Schenkel, Mark C. Rudolph, Timothy James Schlichter, Thomas F. Guevin
  • Patent number: 5157659
    Abstract: An apparatus and method of communicating data signals on a bus having an upstream portion to which transmitters of a plurality of station are connected, and a downstream portion to which receivers of the stations are connected, and to which an end station is connected having a transmitter connected more upstream than any of the plurality of stations. Signals to be transmitted from each of the plurality of stations are appended to the end of the data stream passing thereby. A bus clear signal is transmitted from the end station, along the bus. When any signal including the bus clear signal is detected from upstream at any of the plurality of stations that might be transmitting, transmission of signals from the plurality of stations is immediately terminated. Transmission of the bus clear signal from upstream thus clears the bus to allow for transmission of different priority signals on the bus.
    Type: Grant
    Filed: June 7, 1990
    Date of Patent: October 20, 1992
    Assignee: Canai Computer and Network Architecture Inc.
    Inventor: David P. Schenkel
  • Patent number: 4796022
    Abstract: A bus system for exchanging information between a plurality of circuits connected to the system. The bus system includes a polling bus, a message bus, and a bus controller. The bus controller polls each circuit to see if the circuits require access to the message bus. Information between the circuits is conveyed by first transmitting the information to the bus controller where it is temporarily stored. That information is then sent to the destination circuit by the bus controller. Information is thus conveyed over the message bus twice for every exchange of informaton between two circuits.
    Type: Grant
    Filed: May 5, 1988
    Date of Patent: January 3, 1989
    Assignee: Northern Telecom Limited
    Inventors: David P. Schenkel, Frank Mellor
  • Patent number: 4712213
    Abstract: Fault checking of slave devices. All the slave devices are polled periodically by a master control circuit and their reponse is noted. The master control circuit asserts a control signal for every other poll so as to cause the slave device to invert the bits in its response signal when the control signal is asserted. The non-inversion of the bits during the period of several polls is indicative of either a fault condition or a device not present condition.
    Type: Grant
    Filed: December 11, 1985
    Date of Patent: December 8, 1987
    Assignee: Northern Telecom Limited
    Inventors: Alastair A. Warwick, David P. Schenkel, Kenny Y. Ng