Steven B Witmer

US Patent:

6396877, May 28, 2002

Filed:

Jan 27, 1998

Appl. No.:

09/013943

Inventors:

Keith Eugene Hollenbach - Reading PA
Donald Raymond Laturell - Upper Macungie PA
Steven Brooke Witmer - Sinking Spring PA

Assignee:

Agere Systems Guardian Corp. - Orlando FL

International Classification:

H04B 1406

US Classification:

375247, 375295

Abstract:

The number of separate signals necessary in a serial interface are reduced by combining a transmit data signal with a clock signal having a rate equal to a multiple of a bit rate of the transmit data signal, before encoding for transmission. The number of separate signals in a serial interface may be reduced further by sigma-delta ( /) encoding the transmit data into 1-bit samples, thus eliminating the need for a frame sync signal. By combining the transmit data with a higher rate clock signal, jitter in the recovered clock signal at the receiving end is greatly reduced or even eliminated. At the receiving end, the higher speed clock is recovered at the multiplied rate, used to latch the transmit data from the combined data and higher clock signal, and divided back to the data rate to provide an original bit clock along with an original transmit data signal.

US Patent:

6421430, Jul 16, 2002

Filed:

Feb 23, 1998

Appl. No.:

09/028061

Inventors:

Keith Eugene Hollenbach - Kutztown PA
Donald Raymond Laturell - Upper Macungie PA
Steven Brooke Witmer - Sinking Spring PA

Assignee:

Agere Systems Guardian Corp. - Orlando FL

International Classification:

H04M 1100

US Classification:

379 9336, 379 9305

Abstract:

A telephone line interface or data access arrangement (DAA) includes a shunt regulator in series with a line modulator. A sense resistor is placed in series between the shunt regulator and line modulator to provide a measurement of an amount of noise in the DAA shunt regulator, which is fed back to the line modulator. The line modulator is capable of adjusting the AC modulation and DC termination presented to the telephone line. The method includes drawing power from the telephone line using a shunt regulator, modulating the telephone line in series with the shunt regulator, sensing a level of noise in the shunt regulator, and feeding back the sensed level of noise to the line modulator.

US Patent:

6553118, Apr 22, 2003

Filed:

Aug 20, 1999

Appl. No.:

09/378771

Inventors:

Lane A. Smith - Easton PA
Steven Brooke Witmer - Sinking Spring PA
Jonathan Herman Fischer - Blandon PA
Donald Raymond Laturell - Allentown PA

Assignee:

Agere Systems Inc. - Allentown PA

International Classification:

H04M 900

US Classification:

37941302, 379 9306, 37938702, 37939002, 37939902

Abstract:

A method and apparatus for controlling the DC line current on a telephone line and reducing the amount of error introduced to the system. The error is reduced by compensating for a DC error term introduced by an analog to digital converter having a DC offset. The DC offset is controlled digitally, allowing software to be used to limit the DC error in accordance with predefined parameters. Predefined parameters can be set to accommodate varying country specifications instead of using switches to control resistors and capacitors. In addition, changes in a countrys requirements can be accomplished through software, instead of changing components or redesigning a circuit board. The use of software results in increased flexibility by allowing an infinite number of settings via software or software updates, allowing changes to be made quickly and easily throughout the world, and allowing error terms to be accommodated digitally.

US Patent:

6731728, May 4, 2004

Filed:

Apr 7, 1998

Appl. No.:

09/055991

Inventors:

Keith Eugene Hollenbach - Kutztown PA
Donald Raymond Laturell - Upper Macungie PA
Steven Brooke Witmer - Sinking Spring PA

Assignee:

Agere Systems Inc. - Allentown PA

International Classification:

H04M 1100

US Classification:

379 9336, 379 9305

Abstract:

A telephone line interface or data access arrangement (DAA) is provided which draws power for the customer premises equipment from the telephone line. The DAA includes a shunt regulator as the power source drawing power from the telephone line, and a line modulator in series with the shunt regulator. A sense resistor is placed in series between the line modulator and shunt regulator to sense the line current. Accordingly, DC termination and AC modulation characteristics as presented by the DM to the telephone line can be adjusted by variation of an AC signal with DC offset input to the amplifier driving the line modulator without requiring a different DAA for use in regions or countries having various DC termination and AC modulation requirements. The differential feedback from a sense resistor reduces the noise induced in the circuit from the shunt regulator.

US Patent:

6744888, Jun 1, 2004

Filed:

Nov 16, 1998

Appl. No.:

09/192712

Inventors:

Tony El-Kik - Allentown PA
Keith E. Hollenbach - Kutztown PA
Donald R. Laturell - Allentown PA
Steven B. Witmer - Sinking Spring PA

Assignee:

Agere Systems Inc. - Allentown PA

International Classification:

H04M 100

US Classification:

379412, 37939901, 37939902, 37941302, 37941303, 37941304

Abstract:

A telephone line interface circuit with event detection capabilities is provided that screens out transient signals and provides an indication to the line side that an actual event has occurred; so that appropriate discrimination circuitry is powered up to determine the exact nature of the actual event only when needed. An event detector develops an AC signal that represents the events to be detected. This AC signal is timed to determine its sustained rate. The sustained rate has a timing threshold which is higher than a transient that occurs on the line. If the incoming signal does not meet the required threshold timing, it is disregarded as being transient and no action is taken. If the incoming signal meets the threshold requirement, the line interface circuit switches to the full power mode and facilitates the actual data transmission.

US Patent:

6920218, Jul 19, 2005

Filed:

Nov 16, 1998

Appl. No.:

09/192651

Inventors:

Timothy W. Fuehrer - Phillipsburg NJ, US
Keith E. Hollenbach - Reading PA, US
Donald R. Laturell - Allentown PA, US
Steven B. Witmer - Sinking Spring PA, US

Assignee:

Agere Systems Inc. - Allentown PA

International Classification:

H04M001/00
H04M009/00

US Classification:

37939901, 37939902, 379400, 379401

Abstract:

Disclosed is a method and apparatus which facilitates the use of existing power that is ordinarily unused or discarded to provide power to a telephone interface circuit when the circuit is in the on-hook state, thereby alleviating the need to use loop current to power the interface during the on-hook state. Existing clock signals are used to charge capacitors that are normally used for capacitive coupling of digital data across the high voltage isolation barrier. Although only small-value capacitors are needed for transmitting data across the capacitive interface, larger-value capacitors are used and are configured to form a charge pump to generate power to the interface at all times. Thus the interface always has a steady source of power available for use, including during the on-hook state for powering circuitry that can detect, modulate, and transmit on-hook signals across the capacitive interface.

US Patent:

6999581, Feb 14, 2006

Filed:

Nov 16, 1998

Appl. No.:

09/192654

Inventors:

Tony El-Kik - Allentown PA, US
Keith E. Hollenbach - Kutztown PA, US
Donald R. Laturell - Allentown PA, US
Steven B. Witmer - Sinking Spring PA, US

Assignee:

Agere Systems Inc. - Allentown PA

International Classification:

H04M 3/00

US Classification:

379382, 379377, 379372, 37939901, 37939902

Abstract:

A network interface circuit that screens out transient signals and provides an indication to the line side that an actual event has occurred, so that appropriate discrimination circuitry is powered up to determine the exact nature of the actual event only when actually needed. The present invention develops an AC signal that represents the events that are desired to be detected. This AC signal is timed so that it has a sustained rate (e. g. , a 1 millisecond burst) that is unlike any transient that would occur on the line. Thus, unless the incoming signal meets the timing requirements of the circuit, it is disregarded as a being a transient and no action is taken to determine the exact nature of the signal. This avoids the need to invoke the discrimination circuits that have large power requirements until they are actually needed.

US Patent:

61989444, Mar 6, 2001

Filed:

Dec 4, 1998

Appl. No.:

9/205601

Inventors:

Keith Eugene Hollenbach - Kutztown PA
Donald Raymond Laturell - Upper Macungie PA
Steven Brooke Witmer - Sinking Spring PA

Assignee:

Lucent Technologies, Inc. - Murray Hill NJ

International Classification:

H04Q 732

US Classification:

455557

Abstract:

The present invention provides a method for interlocking a connector for a communication card including a first connection portion for connection to signals in the communication card relating to a first device such as a cellular telephone. A second connection portion in the interlocking connector provides for connection to signals in the communication card relating to a second device such as the PSTN. A blocking portion of the interlocking connector prevents electrical connection with the second connection portion and allows electrical connection with the first connection portion when the interlocking connector is connected to the communication card. A communication card is also provided which comprises modem circuitry, and an interface for connection between the modem circuitry and a computing device. A PSTN interface is provided for connection between the modem circuitry and a telephone line, and a cellular telephone interface is provided for connection between the modem circuitry and a cellular telephone. An interlocking connector prevents electrical connection of the PSTN interface to the telephone line when connected to the cellular telephone interface.