Hal Keen’s Résumé

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Henry (Hal) Keen
Programmer, Analyst, Software Engineer



Career History



Addendum: Patents


Programmer and software analyst experienced in

  • Software design, programming, testing, maintenance and user documentation
  • Data communications, especially LAN and user interfaces, SNA and IP protocols, and IEEE LAN standards
  • Creating and enhancing software tools
  • Customer interaction

Career emphasis on product quality and scalable performance

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NCR Corporation, Roseville, Minnesota, 1985-2001
   Global supplier of technology solutions and support

Solutions Engineer, 1999-2001

  • Provided direct telephone support to customers for UNIX and Cisco products, including problem analysis, installation and configuration assistance, and performance tuning.
  • In addition to customer support, performed maintenance on NCR communications products, writing and testing software updates and revising user manuals.
  • Extended test lab capabilities to address software scaling and performance issues.
  • Obtained a patent on techniques for detecting data corruption in network tests.

Software Engineer, 1990-1999, reaching Senior Principal level

  • Stabilized three generations of Token Ring peripherals and associated system interfaces, developing and releasing hundreds of updates to software and user manuals. Worked primarily in the C language; recent versions used a systems environment based on UNIX STREAMS.
  • To meet evolving test requirements, designed, developed, and continually enhanced a LAN-based SNA test station supporting a wide variety of session configurations and data exchanges.
  • Implemented peripheral device support for the SNA INN Token Ring product feature, collaborating with a parallel development group to define and meet their interface requirements.
  • Fixed LAN protocol thrashing and internal queue overloads by redesigning data flow control at the adapter interface.
  • Participated in the IEEE LAN and MAN Standards Committee as a member of working groups 802.1 (bridging, architecture, management, addressing, access control, virtual LANs) and 802.2 (Logical Link Control).
  • Invented and patented a performance improvement for selective retransmission protocols: a more effective way to avoid redundant transmissions.

Network Engineer, 1987-1990

  • Evaluated feature compatibility by comparison testing of NCR and competitor products.
  • Extended test capacity by creating new trace analyzer programs, and by enhancing a scripted LAN station simulator.

Protocol Engineer, 1985-1987

  • Corrected and verified protocol specifications for LPDA multiplexed modem diagnostics by planning and executing formal tests.

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B.S., Computer Science and Mathematics majors, University of Wisconsin, Platteville, Wisconsin

B.A., Michigan State University, East Lansing, Michigan

Professional training includes:

  • Cisco routers and switches
  • UNIX System V and STREAMS
  • Software engineering for quality
  • Performance programming
  • C and C++ programming languages
  • SNA networks, including IBM NCP internals

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Institute of Electrical and Electronics Engineers (IEEE)
IEEE Standards Association
IEEE standards Working Group 802.1 (voting member since 1987)

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Addendum: PATENTS

These patents are cited as evidence of ability and creativity; the rights are retained by the employer for whom the work was done.

I used to have each of these linked to the Patent Office online versions, but they keep changing the lookup format.

United States Patent 5,664,091: Method and system for avoiding unnecessary retransmissions using a selective rejection data link protocol

Issued: September 2, 1997

This variation on data communications protocols improves the efficiency of selective retransmission algorithms for both point-to-point and multicast data links, by more reliably determining when retransmissions are required.

United States Patent 6,044,480: Message generation and verification for a communication network

Issued: March 28, 2000

This is a method of testing the correct operation of data channels in a communications network. Test data is generated in a self-documenting pattern, so it can be verified at the receiver without requiring a master copy for comparison. The test messages can vary in content, and can be extended to any required length. A higher-efficiency version of the method can be used to check specifically for errors in segmentation and reassembly.

An implementation in test software saw extensive use in a communications laboratory.

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