computer science

PictureTel

PictureTel is a computer science 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 PictureTel rather than just read about it. In short: PictureTel Corporation was one of the first commercial videoconferencing product companies. It achieved peak revenues of over $490 million in 1996 and 1997 and was eventually acquired by Polycom in October 2001.

Key takeaways

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

Reference excerpt

PictureTel Corporation was one of the first commercial videoconferencing product companies. It achieved peak revenues of over $490 million in 1996 and 1997 and was eventually acquired by Polycom in October 2001.

History PictureTel was founded in August 1984 as PicTel by MIT students Brian L Hinman, Jeffrey G. Bernstein and MIT Professor David H. Staelin. The team was also assisted initially by MIT Professor Michael Dertouzos and two of his grad students Greg Papadopoulos and Richard Soley. The founding CEO was Ronald S. Posner Ph.D. While at MIT Hinman and Bernstein were motivated by the video compression work by UC Davis Professor Anil K. Jain (1946–1988) and his colleague Jaswani R. Jain who published an important research paper combining block-based motion compensation and transform coding in December 1981. The result was PictureTel, creating one of the first real-time systems to implement motion compensation and transform coding in July 1986. PictureTel was funded as "PicTel" by an initial public offering in November 1984, becoming a public company on virtually its first day of business. Product development started at this point. Its name was changed to PictureTel in 1987, due to concern about potential name conflict with another communications company, Pacific Telephone Co., also known as PacTel. While the company demonstrated its first product in 1986, the company did not have meaningful product sales until 1987. PictureTel's first product, the C-2000 codec (compressor/decompressor) was the first commercial implementation of this computationally intensive technology. By analyzing the motion between successive frames rather than treating the frames as a sequence of unrelated images, this algorithm was significantly more data-efficient (required the transmission of much less data) than existing techniques. Requiring less data also meant that it was compatible with emerging dial-up data networks such as ISDN, making its use less expensive and more flexible than the leased, fixed-location lines normally used for high-speed data transmission at the time. Subsequently, most of the video compression standards for two-way communications and video broadcast applications have been based upon motion compensation and transform coding, including those most widely used today such as H.264/MPEG-4 AVC. PictureTel played a strong role in developing the industry standards for video, audio, and data communications, and released much of its technology for use free of charge. In October 2001, PictureTel was purchased by Polycom, a company that was co-founded in 1990 by Brian Hinman and another early PictureTel employee, Jeffrey Rodman. Hinman and Bernstein would later be instrumental in creating 2Wire.

See also Ascend Communications Bonding protocol Compression Labs Inc. International Multimedia Telecommunications Consortium

References

Bibliography Smith, Tom (May 14, 1990). PictureTel Codec Software to Improve Video, Audio. Vol. 7. IDG Network World Inc. p. 26. {{cite book}}: |magazine= ignored (help) Margolis, Nell (December 17, 1990). PictureTel Prospers in Tough Times. Vol. 24. IDG Enterprise. p. 73. {{cite book}}: |magazine= ignored (help) Brown, Bob (October 19, 1992). PictureTel Sets Sights on Desktop Market. Vol. 9. IDG Network World Inc. p. 29. {{cite book}}: |magazine= ignored (help) Wexler, Joanie M. (May 17, 1993). PictureTel Makes Videoconferencing Cheaper. Vol. 27. IDG Enterprise. p. 58. {{cite book}}: |magazine= ignored (help) Chen, Steven C.M. (June 14, 1994). PictureTel Corp. - PictureTel Live PCS 100. Vol. 13. Ziff Davis, Inc. p. 251. {{cite book}}: |magazine= ignored (help) Messmer, Ellen (January 23, 1995). PictureTel to Unveil Group Share Data Collaboration Software. Vol. 12. IDG Network World Inc. p. 4. {{cite book}}: |magazine= ignored (help) Cope, James (September 25, 2000). Caterpillar to Launch Satellite Videoconferencing System. Vol. 34. IDG Enterprise. p. 88. {{cite book}}: |magazine= ignored (help)

External links MIT & PictureTel Archived 2010-07-20 at the Wayback Machine CNET PictureTel 900 Series Root, Timothy D. (January 2000). "Audio Communications Product Strategy for the 21st Century" (PDF). DSpace@MIT. Massachusetts Institute of Technology. IT World Staff (April 16, 2001). "PictureTel Slims Down Videoconferencing Device". IDG Communications, Inc. 1993 PictureTel Promotion on YouTube 1995 PictureTel New York Product Launch on YouTube

Illustrations

Worked examples

Example 1 — a first encounter with PictureTel

Start with the simplest possible case. Write down what PictureTel claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, 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 PictureTel 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 PictureTel 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 PictureTel

In research: PictureTel appears in computer science 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 PictureTel 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: PictureTel is common in secondary-school and first-year university syllabi. It links to neighbouring topics Defunct computer companies of the United States, Defunct computer hardware companies, Defunct software companies of the United States, so understanding it makes those chapters shorter.
In everyday life: Look for PictureTel 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 PictureTel in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PictureTel 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 PictureTel out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PictureTel in simple terms?

Why does PictureTel matter?

Because it connects several computer science 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 PictureTel?

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 PictureTel.