engineering

Phil Karn

Phil Karn is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Phil Karn rather than just read about it. In short: Phil Karn (born October 4, 1956) is a retired American engineer from Lutherville, Maryland. Early life and education He earned a bachelor's degree in electrical engineering from Cornell University in 1978 and a master's degree in electrical engineering from Carnegie Mellon University in 1979.

Key takeaways

Phil Karn belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Phil Karn to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Phil Karn from memory before moving on to harder problems.

Reference excerpt

Phil Karn (born October 4, 1956) is a retired American engineer from Lutherville, Maryland.

Early life and education He earned a bachelor's degree in electrical engineering from Cornell University in 1978 and a master's degree in electrical engineering from Carnegie Mellon University in 1979.

Career

Academic career From 1979 until 1984, Karn worked at Bell Labs in Naperville, Illinois, and Murray Hill, New Jersey. From 1984 until 1991, he was with Bell Communications Research in Morristown, New Jersey. From 1991 through to his retirement, he worked at Qualcomm in San Diego, where he specialized in wireless data networking protocols, security, and cryptography.

Amateur Radio Digital Communications He is currently a board member and President Emeritus of Amateur Radio Digital Communications (ARDC), a non-profit foundation funded by the sale of part of its IP address space (44/8). ARDC manages the remaining portion of its address space by providing financial grants to amateur radio, digital communications and related groups.

Internet Engineering Task Force He has been an active contributor in the Internet Engineering Task Force, especially in security, and to the Internet architecture. He is the author or co-author of at least 6 RFCs, and is cited as contributing to many more. He is the inventor of Karn's Algorithm, a method for calculating the round trip time for IP packet retransmission. In 1991, Thomas Alexander Iannelli's Master's thesis judged Karn's KA9Q NOS software as more suitable for deployment than an Air Force Institute of Technology packet radio system. In 1990, Karn was one of the first to predict that the use of wired links for the Internet's "capillaries" would become "history" because most users would access it via wireless radio links.

Amateur radio and KA9Q He is well known in the amateur radio community for his work on the KA9Q Network Operating System (NOS), named after his amateur callsign. He also created early 9600 bit/s FSK radio modems. In the early 2000's, Karn worked to introduce forward error correction into Amateur radio satellites, applying it to the 400 bit/s PSK telemetry from the AO-40 satellite. He won the 1989 Specific Achievement Award at the Dayton Hamvention. In 1994, Carl Malamud interviewed Karn on Internet Talk Radio for his "Geek of the Week" podcast. They talked about the KA9Q software, Qualcomm's CDMA radio technology for data transfer, the Globalstar low Earth orbit satellite radio system, Mobile IP, the Clipper chip, and encryption. In June 2014, Karn was also interviewed for the History of the Internet Project, in which he described his contribution to the effort to reboot the 1978 International Sun/Earth Explorer-3 (ISEE-3) spacecraft. The ISEE-3 is also known as the International Cometary Explorer.

Crypto export lawsuit In 1994, the US State Department Office of Defense Trade Control ruled that while it was legal to export Bruce Schneier's "Applied Cryptography" book under the rules for munitions export, it was illegal to export the source code in the book on electronic media such as a floppy disk. The case was tried in Washington D.C. Federal District Court (1996), and the judge handed down a summary judgment in favor of the State Department. He ruled that the book and it contents were free to be exported, protected by free speech and press rights. The floppy disk, however, was a tool or instrument designed to produce functioning products (e.g. an encrypted computer) and as such was subject to the controls of the Export Control Act. Karn challenged this ruling, both in the courts and in testimony before Congress for two years, until Bill Clinton dropped almost all export controls on freely available crypto source code on January 14, 2000; the judge mooted the case.

References http://www.loundy.com/CASES/Karn_v_US.html

Sources "Phil Karn's page on the crypto export case". Retrieved February 6, 2008. : Self-published or questionable sources: http://www.ka9q.net/ is subject's personal web page.

External links Phil Karn's personal webpages FEC Encoding for AO-40 Telemetry Phil Karn's profile on Quora

Worked examples

Example 1 — a first encounter with Phil Karn

Start with the simplest possible case. Write down what Phil Karn claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Phil Karn before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Phil Karn ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Phil Karn

In research: Phil Karn appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Phil Karn in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Phil Karn is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1956 births, Amateur radio people, Carnegie Mellon University College of Engineering alumni, so understanding it makes those chapters shorter.
In everyday life: Look for Phil Karn outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Phil Karn in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Phil Karn means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Phil Karn out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Phil Karn in simple terms?

Phil Karn (born October 4, 1956) is a retired American engineer from Lutherville, Maryland. Early life and education He earned a bachelor's degree in electrical engineering from Cornell University in 1978 and a master's degree in electrical engineering from Carnegie Mellon University in 1979.

Why does Phil Karn matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Phil Karn?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Phil Karn.