Richard Brian Flanagan

US Patent:

6693972, Feb 17, 2004

Filed:

Dec 7, 1999

Appl. No.:

09/456159

Inventors:

Richard Thomas Flanagan - Freehold NJ 07728

International Classification:

H04L 2704

US Classification:

375295, 375222

Abstract:

A data apparatus (e. g. , a modem) continues to generate an analog line signal acceptable to a remote data apparatus receiver when software fails to deliver samples used to generate the line signal to the hardware in time. The data apparatus uses symbols, rather than samples, which are transmitted from a data-pump unit software to an analog front-end (AFE) unit to generate the analog line signal. When the data-pump is late in providing a new set of symbols, the AFE unit uses previous symbols, randomized versions of previous symbols, or some other source of acceptable symbols to generate a transmit line signal. While data errors will still occur, these data errors are a normal occurrence for data apparatus and a link-layer protocol will detect and retransmit the erred data. The invention avoids having the line signal distorted, which can create data transmission outages due to the remote data apparatus entering into a rate change, initiating a retrain operation, or failing entirely.

US Patent:

51627620, Nov 10, 1992

Filed:

Mar 25, 1991

Appl. No.:

7/673992

Inventors:

Richard T. Flanagan - Freehold NJ

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

H03L 7093

US Classification:

331 15

Abstract:

A phase-lock loop includes a scaling element whose scale factor is adaptively adjusted as a function of the value of a state variable in the loop--illustratively, the magnitude thereof. That function is such that, after the adjustment has been made, the value taken on by the state variable is within a predetermined range. In particular embodiments, the scale factor and the state variable are simultaneously adjusted reciprocally, rather than simply adjusting only the scale factor and waiting for the normal operation of the loop to change the state variable, advantageously minimizing any transient degradation in loop performance that may occur as a result of the adjustment.

US Patent:

60090839, Dec 28, 1999

Filed:

Feb 12, 1998

Appl. No.:

9/022708

Inventors:

Richard Thomas Flanagan - Freehold NJ
Jean-Jacques Werner - Holmdel NJ

Assignee:

Lucent Technologies, Inc. - Murray Hill NJ

International Classification:

H04B 323

US Classification:

370287

Abstract:

The problem of tracking rapid changes in the echo signals associated with modems is eliminated by using an echo canceler consisting of cascaded adaptive filters. Each filter in the structure contributes to the modeling of the overall echo path impulse response, with a longer filter providing the ability to model long echo path impulse responses and a shorter filter providing the ability to track changes in the echo path impulse response over time.

US Patent:

61635693, Dec 19, 2000

Filed:

Aug 19, 1998

Appl. No.:

9/136257

Inventors:

Richard Thomas Flanagan - Freehold NJ

Assignee:

Lucent Technologies, Inc. - Murray Hill NJ

International Classification:

H04B 138
H04L 516

US Classification:

375222

Abstract:

A split-architecture modem splits the physical layer protocol into a logical operations portion and a signal processing portion. A first processor (e. g. , a general purpose processor (GPP)) of the modem performs the logical operations of the physical layer protocol along with the data link layer protocol. A second processor (e. g. , a digital signal processor (DSP)) of the modem performs the signal processing portion of the physical layer protocol.

US Patent:

55749909, Nov 12, 1996

Filed:

Nov 20, 1995

Appl. No.:

8/559888

Inventors:

Richard T. Flanagan - Freehold NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 1700

US Classification:

455115

Abstract:

The problem of noise enhancement is eliminated in communications systems by predistorting the amplitude of the transmitted information signal in a manner which compensates for the amplitude distortion introduced in a portion of the communications channel. In the disclosed embodiments, the communications system includes two signal transceivers which communicate with one another through a communications channel. The communications channel includes two-wire subscriber loops adjacent to each signal transceiver with a four-wire transmission path disposed between the subscriber loops. Each transceiver transmits an information signal which, depending on the system noise characteristics, is predistorted to compensate for all or a portion of the amplitude distortion introduced in a subscriber loop adjacent to that signal transceiver. The predistortion necessary to provide such compensation is determined at each transceiver in response to a received narrowband signal at that transceiver. Advantageously, this narrowband signal may be that used to disable echo cancellers and/suppressors in the communications channel.

US Patent:

58154965, Sep 29, 1998

Filed:

Sep 29, 1995

Appl. No.:

8/536905

Inventors:

Richard Thomas Flanagan - Freehold NJ
Jean-Jacques Werner - Holmdel NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 323

US Classification:

370287

Abstract:

The problem of tracking rapid changes in the echo signals associated with modems is eliminated by using an echo canceler consisting of cascaded adaptive filters. Each filter in the structure contributes to the modeling of the overall echo path impulse response, with a longer filter providing the ability to model long echo path impulse responses and a shorter filter providing the ability to track changes in the echo path impulse response over time.