Darrell Furlong

Title: Innovations by Darrell Furlong

Introduction

Darrell Furlong is an accomplished inventor based in Uxbridge, MA (US). He has made significant contributions to the field of local area network technology, holding two patents that showcase his innovative spirit and technical expertise.

Latest Patents

Furlong's latest patents include a local area network modem and a symbol detection and error correction coding system for local area network modems. The local area network modem meets the stringent signaling requirements of the IEEE 802.4 standard. It supports loopback commands by ensuring that the receiver and transmitter portions are in phase-synchronism, regardless of the physical distance between the modem and upper layer control circuitry. The modem's design utilizes only two digital signal wires to specify which functions are to be performed by the transmitter's analog components. An automatic gain control (AGC) circuit is included, which eliminates several issues associated with prior designs. Notably, the modem's receiver monitors itself to automatically correct drift in phase and gain control adjustment without requiring intervention from the upper layer.

The second patent focuses on a symbol detection and correction scheme for local area network modems, particularly those that receive one of three symbols at any given time, in accordance with the IEEE 802.4 standard. This invention significantly improves the bit error rate observed by the layer above the modem. The modem operates on a received signal with a pair of slicers, one functioning as a two-symbol detector and the other as a three-symbol detector. A receiver state machine tracks which portion of a frame is currently expected to be received. Depending on the context, one or both slicer outputs are utilized by the state machine to determine which of the three symbols was received. The receiver state machine can recognize errors in pseudo-silence, start delimiter, and end-delimiter sequences without reporting such errors to the upper level, thereby greatly decreasing the error rate observed.

Career Highlights

Darrell Furlong is currently employed at Concord Communications, Inc., where he continues to innovate and contribute to advancements in network technology. His work has had a lasting impact on the efficiency and reliability of local area networks.

Collaborations

Due to space constraints, the collaborations section will be omitted.

Conclusion

Darrell Furlong's contributions to local area network technology through his patents demonstrate his innovative capabilities and commitment to improving communication systems.