David H Lyon

US Patent:

39551415, May 4, 1976

Filed:

Oct 18, 1974

Appl. No.:

5/515877

Inventors:

David L. Lyon - Cambridge MA
Jerry L. Holsinger - Burlington MA
David E. Williams - Andover MA

Assignee:

Intertel, Inc. - Burlington MA

International Classification:

H04B 100
H04L 700

US Classification:

325 38A

Abstract:

A modem with transmitter and reciever sections. Incoming digital data signals produce successive coordinate signals to define successive transmission points representing a given digital value and to modulate quadrature carrier signals. The coordinate signals have unit values of 0, 1, 2. 707, 3 and 5 and together control the amplitude and phase of the modulated carrier signals. The receiver section uses received coordinate signals, after they are properly conditioned, to select a decision region which corresponds to a transmission point to produce the digital data signals. The decision regions have rectilinear boundaries on a Cartesian coordinate system at unit values 0, 1. 25, 2 and 4 and each region is either rectangular or non-rectangular. Digital synchronism between separate modems is maintained by transmitting coordinate signals corresponding to a framing point which is separate from the transmission points, but which has the same digital value as a transmission point. Certain decision regions defined by the receiver use the receipt of the modulated carrier signals corresponding to a framing point to initiate a synchronizing operation.

US Patent:

45450110, Oct 1, 1985

Filed:

Dec 10, 1980

Appl. No.:

6/215135

Inventors:

David L. Lyon - Cambridge MA
Robert E. Huettner - Acton MA
Jerry L. Holsinger - Boston MA
Don I. Falkenstein - Lexington MA
Imtiaz Piracha - Peabody MA
Dennis T. Ching - Cambridge MA

Assignee:

Infinet Inc. - Andover MA

International Classification:

G06F 1516

US Classification:

364200

Abstract:

A network control and test system for application to data communications networks. In a first mode of operation, the system learns the network configuration automatically and builds a table describing the network configuration. In a second mode of operation, the system automatically monitors the status of the network and each of its component units, periodically polling the network for changes of status and updating the information in the network configuration table to reflect such changes. In a third mode of operation, selective sites in the network may be tested under control of the system at previously selected and entered times of day, at which times previously chosen tests are performed without the need for operator intervention. In a fourth mode, an operator can manually command the system to perform certain tests and control functions. A central site in the network includes the primary components of the system and each remote site includes a remote test module which operates under the control of and in cooperation with the central site equipment.

US Patent:

40558088, Oct 25, 1977

Filed:

May 20, 1976

Appl. No.:

5/688330

Inventors:

Jerry L. Holsinger - Boston MA
David L. Lyon - Cambridge MA
David E. Williams - Andover MA
Frank B. Lezotte - Chelmsford MA
Don I. Falkenstein - Burlington MA

Assignee:

Intertel, Inc. - Burlington MA

International Classification:

H04B 172

US Classification:

325 67

Abstract:

A testing facility for a data communications network including modulators and demodulators, or modems, at central sites, at intermediate, or hubbing, sites, and at remote sites. Hubbing site testing units connect to respective host modems at the intermediate sites. The central testing unit transmits control words containing line address, drop address, and command characters. A configuration control circuit in each hubbing site testing unit generates signals that designate the particular location of the testing unit at the hubbing site. A validation circuit in each testing unit enables the testing unit to respond to the command character if two valid control words are received in succession. Thereafter the testing unit transmits back to the central testing unit signals in response to the test defined by the command character. If the line and drop address characters do not designate that specific hubbing site testing unit, it repeats the command to other units as an outbound request and repeats inbound responses to the central testing unit.

US Patent:

45450137, Oct 1, 1985

Filed:

Dec 31, 1981

Appl. No.:

6/336296

Inventors:

David L. Lyon - Cambridge MA
Robert E. Huettner - Acton MA
Jerry L. Holsinger - Boston MA
Don I. Falkenstein - Lexington MA
Imtiaz Piracha - Peabody MA
Dennis T. Ching - Cambridge MA

Assignee:

Infinet Inc. - Andover MA

International Classification:

G06F 1516

US Classification:

364200

Abstract:

A network control and test system for application to data communications networks. In a first mode of operation, the system learns the network configuration automatically and builds a table describing the network configuration. In a second mode of operation, the system automatically monitors the status of the network and each of its component units, periodically polling the network for changes of status and updating the information in the network configuration table to reflect such changes. In a third mode of operation, selective sites in the network may be tested under control of the system at previously selected and entered times of day, at which times previously chosen tests are performed without the need for operator intervention. In a fourth mode, an operator can manually command the system to perform certain tests and control functions. A central site in the network includes the primary components of the system and each remote site includes a remote test module which operates under the control of and in cooperation with the central site equipment.

US Patent:

40370496, Jul 19, 1977

Filed:

Oct 18, 1974

Appl. No.:

5/515878

Inventors:

David L. Lyon - Cambridge MA

Assignee:

Intertel, Inc. - Burlington MA

International Classification:

H04L 2718

US Classification:

178 67

Abstract:

A modem with transmitter and receiver sections. Incoming digital data signals produce successive coordinate signals to define successive transmission points representing a given digital value and to modulate quadrature carrier signals. The coordinate signals have unit values of 0, 1, 2. 707, 3 and 5 and together control the amplitude and phase of the modulated carrier signals. The receiver section uses received coordinate signals, after they are properly conditioned, to select a decision region which corresponds to a transmission point to produce the digital data signals. The decision regions have rectilinear boundaries on a Cartesian coordinate system at unit values 0, 1. 25, 2 and 4 and each region is either rectangular or non-rectangular. Digital synchronism between separate modems is maintained by transmitting coordinate signals corresponding to a framing point which is separate from the transmission points, but which has the same digital value as a transmission point. Certain decision regions defined by the receiver use the receipt of the modulated carrier signals corresponding to a framing point to initiate a synchronizing operation.