Patents by Inventor Robert P. McNamara

Robert P. McNamara 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).

  • Patent number: 5436902
    Abstract: A telecommunication bridge system uses synchronized arbitration in a portion of a frame of a Radio Frequency (RF) subsystem and is transparent to Ethernet layer protocols and Ethernet-type packets in order to increase bandwidth utilization and effectively extend Ethernet networks to metropolitan-area-wide application. The telecommunication bridge system comprises an enhanced Ethernet network interface subsystem coupled to a conventional Ethernet medium and a control subsystem including an RF modem, in turn coupled to a frame synchronized RF medium in a metropolitan-sized network. On one side the control subsystem emulates all Ethernet layer protocols and on the other side conducts a prioritized arbitration scheme during only a portion of a time division multiplexed frame, the remainder of the frame for carrying a payload of unmodified packets to other bridges.
    Type: Grant
    Filed: April 5, 1994
    Date of Patent: July 25, 1995
    Assignee: First Pacific Networks
    Inventors: Robert P. McNamara, Amar Amar
  • Patent number: 5408507
    Abstract: An apparatus and method for extending the range of a digital data network by enhancing skew control. The apparatus is a circuit for use in a network interface unit. The apparatus measures the distance of the network interface unit from the head-end retransmission unit of the network by transmitting a series of signal packets on the network and counting the time it takes for the packets to be received back at the interface unit. All transmissions on the network take place with reference to a timing mark transmitted by the head-end unit at a regular interval. The apparatus sends the first in the series of signal packets at a pre-determined pre-skew interval before the timing mark. The apparatus counts the number of clock cycles after the timing mark before the signal packet is received back at the network interface unit.
    Type: Grant
    Filed: April 27, 1993
    Date of Patent: April 18, 1995
    Assignee: First Pacific Networks, Inc.
    Inventors: Robert P. McNamara, Amar C. Amar, Prabhakara C. Balla, Hung C. Pon, Chuan-Lung Chao, Chongzhen Wang
  • Patent number: 5272700
    Abstract: A baseband signal is spectrally efficiently transmitted on a broadband transmission medium by inserting gaps in packets of digital data transmitted in a modulated first radio frequency carrier. The transmitted packets of data are received by demodulating the modulated first radio frequency carrier, and the gap is monitored for the presence of digital data thus indicating a collision of simultaneously transmitted packets of digital data. A seed of arbitrary digital bits are used in scrambling each packet of digital data and is transmitted with the packet of data for use in descrambling the data. In retransmitting the packet of data the seed is included. The originally transmitting node receives the retransmitted packet and compares the retransmitted seed with the originally transmitted seed for detecting an error in retransmission.
    Type: Grant
    Filed: October 17, 1991
    Date of Patent: December 21, 1993
    Assignee: First Pacific Networks, Inc.
    Inventors: David E. Hansen, Robert P. McNamara, James C. Long, Michael J. Serrone, Chinh Q. Phan, Long K. Tran
  • Patent number: 5255267
    Abstract: Apparatus for combining broadband RF signals and baseband signals in a baseband distribution cable includes a bridge for coupling the distribution cable to an RF broadband trunk and to a baseband repeater. The trunk is connected through bidirectional amplifier, an impedance transformer, and a signal splitter for applying the amplified and impedance transformed broadband signal to a plurality of baseband segments. The RF signal from the splitter is passed through a 35 MHz high pass filter to the baseband segment. Baseband signals from a repeater are passed through a 25 MHz low pass filter to the baseband segment. The two filters prevent interference between the baseband and broadband signals.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: October 19, 1993
    Assignee: First Pacific Networks, Inc.
    Inventors: David E. Hansen, Robert P. McNamara, Chinh Q. Phan, Michael J. Serrone
  • Patent number: 5088111
    Abstract: A communication network having a first broadband communications channel or transmitting bus and a second broadband communications channel or receiving bus, wherein the first broadband communications channel is for passing information upstream to a head end and the second broadband communications channel is for passing information downstream from the head end to remote nodes. All nodes of the system are coupled to both the first communications channel and the second communications channel. According to the invention, modulation of signals applied to the first communication channel is optimized for burst communication from a plurality of sources to central control at the head end, and modulation applied to the second communications channel is optimized for continuous communication from the central source to a target node.
    Type: Grant
    Filed: February 28, 1989
    Date of Patent: February 11, 1992
    Assignee: First Pacific Networks
    Inventors: Robert P. McNamara, Timothy P. Murphy
  • Patent number: 5084903
    Abstract: A communication network having a first broadband communications channel or transmitting bus and a second broadband communications channel or receiving bus, wherein the first broadband communications channel passes information upstream to a head end employing an offset quadrature phase shift keyed (OQPSK) modulator in bursts, and the second broadband communications channel passes information downstream from the head end to remote nodes in a continuous bit stream. All nodes of the system are coupled to both the first communications channel and the second communications channel. According to the invention, modulation of signals applied to the first communication channel is optimized for burst communication from a plurality of sources to central control at the head end, and modulation applied to the second communications channel is optimized for continuous communication from the central source to a target node.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: January 28, 1992
    Assignee: First Pacific Networks
    Inventors: Robert P. McNamara, Timothy P. Murphy, James C. Long
  • Patent number: 4533948
    Abstract: A two way digital communication arrangement utilizes a CATV system to provide bidirectional data transport service between any two points within the CATV system. The headend receives an upstream message and selectively rebroadcasts such message on the downstream portion of the spectrum. System intelligence is thus distributed throughout the system as server and subscriber nodes can be located anywhere in the CATV network. In order to obtain access to the CATV communication resources, user equipment at each node must attach a frame verifier (FV) code to each respective message. The headend examines the FV and permits rebroadcast of messages only if the FV code indicates that the user is authorized.
    Type: Grant
    Filed: April 30, 1982
    Date of Patent: August 6, 1985
    Assignee: General Instrument Corporation
    Inventors: Robert P. McNamara, Gregory B. Ennis, Richard J. Feiertag, Robert K. Bauer