Daniel L Thomas

US Patent:

6807525, Oct 19, 2004

Filed:

Oct 31, 2000

Appl. No.:

09/699366

Inventors:

Dunling Li - Rockville MD
Gokhan Sisli - Bethesda MD
Daniel Thomas - Germantown MD

Assignee:

Telogy Networks, Inc. - Germantown MD

International Classification:

G10L 1106

US Classification:

704215

Abstract:

A method to reduce the amount of bandwidth used in the transmission of digitized voice packets is described. The method is used to reduce the number of transmitted packets by suspending transmission during periods of silence or when only noise is present. The system determines if a background noise update is warranted based on human auditory perception factors instead of an artificial limiter on excessive silence insertion descriptor packets. The system searches for characteristics in the perceptual changes of background noise instead of analyzing speech for improved audio compression. The invention weighs factors affecting the perception of sound including frequency masking, temporal masking, loudness perception based on tone, and auditory perception differential based on tone.

US Patent:

7031916, Apr 18, 2006

Filed:

Jun 1, 2001

Appl. No.:

09/871779

Inventors:

Dunling Li - Rockville MD, US
Daniel C. Thomas - Germantown MD, US
Gokhan Sisli - Bethesda MD, US

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G10L 11/06

US Classification:

704233, 704208

Abstract:

A method of initializing an ITU Recommendation G. 729 Annex B voice activity detection (VAD) device is disclosed, having the steps of (1) extracting a set of parameters from a signal that characterize the signal; (2) calculating an energy measure of the signal from the set of parameters; (3) comparing the energy measure with a reference value; (4) determining an initial value for an average of a noise characteristic of the signal; and (5) counting the number of times the energy measure equals or exceeds the reference level. Also disclosed is a method of converging an ITU Recommendation G. 729 Annex B voice activity detection (VAD) device, having the steps of: (1) determining a noise identification threshold value; (2) comparing a number of energy measures of a signal to the noise threshold value; (3) determining a first value representing an average of the number of energy measures, when the energy measure is less than the noise threshold, wherein only the energy measures of the number of energy measures having values less than the noise threshold value are used to determine the first value; (4) determining a second value representing an average of the number of energy measures; and (5) substituting the first value for the second value when a specific event occurs, indicating the divergence of the two values.

US Patent:

7453889, Nov 18, 2008

Filed:

Feb 2, 2005

Appl. No.:

11/047746

Inventors:

Satish Kumar M. Mundra - Germantown MD, US
Daniel C. Thomas - Germantown MD, US

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H04L 12/28
H04L 12/56
H04J 3/16
H04J 3/22

US Classification:

370400, 370401, 370465, 370466, 370467, 370476

Abstract:

Providing interoperability on a voice communication network by detecting incompatible bit packing payload formats of ADPCM encoded voice data signals in an encoder/decoder. A mismatch of bit packing formats between little endian format and big endian format is determined by detecting the occurrence of ADPCM code words of interest in the decoded voice data stream out of the encoder/decoder. The invention may be applied to an ITU G. 726 encoder/decoder.

US Patent:

20060171324, Aug 3, 2006

Filed:

Feb 3, 2005

Appl. No.:

11/050338

Inventors:

Satish Kumar Mundra - Germantown MD, US
Daniel Thomas - Germantown MD, US
David Lide - Rockville MD, US

International Classification:

H04L 12/66
H04L 12/26

US Classification:

370252000, 370352000

Abstract:

Providing interoperability on a voice communication network by detecting incompatible bit packing payload formats of ADPCM encoded voice data signals in an encoder/decoder. A mismatch of bit packing formats between little endian format and big endian format is determined through the use of a media gateway control protocol package called Real Time Protocol that allows a Call Agent to detect the presence of garbled audio and allows an intelligent gateway to detect the payload format being used by remote endpoints during call setup procedures and then switch the gateway's encoding for the payload to the payload format being used by the remote endpoint. The invention may be applied to an ITU G.726 encoder/decoder.

US Patent:

54229740, Jun 6, 1995

Filed:

Sep 23, 1994

Appl. No.:

8/312743

Inventors:

Gair D. Brown - Dahlgren VA
Alan C. Schwarting - Warsaw VA
Robert G. Aldous - King George VA
Daniel D. Thomas - King George VA
Francis L. Needham - Fredericksburg VA
Sara M. Leite - Dahlgren VA

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

G02B 636
G02B 638

US Classification:

385135

Abstract:

Rotary mechanical splices between axially aligned optic fibers are seated der axial compression within bays recessed into the body of a holding tray on which a retention lid is fastened in a position to which it is guided by fins on its underside received in grooves formed in the tray body. In such position of the lid on the tray, the lid underside surface covers access formations and the bays between the fins having portions covering fiber slots in the tray through which the optic fibers extend in alignment with their splices.

US Patent:

54993148, Mar 12, 1996

Filed:

Nov 22, 1994

Appl. No.:

8/345716

Inventors:

Sara M. Leite - Dahlgren VA
Daniel D. Thomas - King George VA
Gair D. Brown - Dahlgren VA
Alan Schwarting - Warsaw VA

International Classification:

G02B 638

US Classification:

385135

Abstract:

Rotary mechanical splices between axially aligned optic fibers are seated in axial confinement within bays indented into the shock absorbing body of a holding tray. A retention lid, positioned on the tray covers the splice seating bays and guide slots extending therefrom within which the optic fibers are received to provide cushioned confinement for the splices and resist relative bending of the fibers.