Jump to content

Paul Baran

From Wikipedia, the free encyclopedia

Paul Baran
Born(1926-04-29)April 29, 1926
DiedMarch 26, 2011(2011-03-26) (aged 84)
CitizenshipPoland, United States
Alma materUCLA (M.S., 1959)
Drexel University (B.S., 1949)
Known forPacket switching
Spouse(s)Evelyn Murphy Baran, PhD
AwardsIEEE Alexander Graham Bell Medal (1990)
Computer History Museum Fellow (2005)[1]
Marconi Prize (1991)
NMTI (2007)
National Inventors Hall of Fame
Scientific career
InstitutionsRAND Corporation

Paul Baran (born Pesach Baran /ˈbærən/; April 29, 1926 – March 26, 2011) was an American-Jewish engineer who was a pioneer in the development of computer networks. He was one of the two independent inventors of packet switching, which is today the dominant basis for data communications in computer networks worldwide, and went on to start several companies and develop other technologies that are an essential part of modern digital communication.

Early life


He was born in Grodno (then in the Second Polish Republic, and since 1945 part of Belarus) on April 29, 1926.[2][3] He was the youngest of three children in his Lithuanian Jewish family,[4] with the Yiddish given name "Pesach". His family moved to the United States on May 11, 1928,[5] settling in Boston and later in Philadelphia, where his father, Morris "Moshe" Baran (1884–1979), opened a grocery store. He graduated from Drexel University (then called Drexel Institute of Technology) in 1949, with a degree in electrical engineering. He then joined the Eckert-Mauchly Computer Company, where he did technical work on UNIVAC models, the first brand of commercial computers in the United States.[6] In 1955 he married Evelyn Murphy, moved to Los Angeles, and worked for Hughes Aircraft on radar data processing systems. He obtained his master's degree in engineering from UCLA in 1959, with advisor Gerald Estrin while he took night classes. His thesis was on character recognition.[2] While Baran initially stayed on at UCLA to pursue his doctorate, a heavy travel and work schedule forced him to abandon his doctoral work.[7]

Packet switched network design

The "block message" as suggested by Paul Baran in 1964, this is the very first data packet that was ever proposed.

After joining the RAND Corporation in 1959, Baran took on the task of designing a "survivable" communications system that could maintain communication between end points in the face of damage from nuclear weapons during the Cold War.[8] Then, most American military communications used high-frequency connections, which could be put out of action for many hours by a nuclear attack. Baran decided to automate RAND Director Franklin R. Collbohm's previous work with emergency communication over conventional AM radio networks and showed that a distributed relay node architecture could be survivable. The Rome Air Development Center soon showed that the idea was practicable.[9]

Using the minicomputer technology of the day, Baran and his team developed a simulation suite to test basic connectivity of an array of nodes with varying degrees of linking. That is, a network of n-ary degree of connectivity would have n links per node. The simulation randomly "killed" nodes and subsequently tested the percentage of nodes that remained connected. The result of the simulation revealed that networks in which n ≥ 3 had a significant increase in resilience against even as much as 50% node loss. Baran's insight gained from the simulation was that redundancy was the key.[10] His first work was published as a RAND report in 1960,[11] with more papers generalizing the techniques in the next two years.[12]

After proving survivability, Baran and his team needed to show proof of concept for that design so that it could be built. That involved high-level schematics detailing the operation, construction, and cost of all the components required to construct a network that leveraged the new insight of redundant links. The result was one of the first store-and-forward data layer switching protocols, a link-state/distance vector routing protocol, and an unproved connection-oriented transport protocol. Explicit detail of the designs can be found in the complete series of reports On Distributed Communications, published by RAND in 1964.[13]

The design flew in the face of telephony design of the time by placing inexpensive and unreliable nodes at the center of the network and more intelligent terminating 'multiplexer' devices at the endpoints. In Baran's words, unlike the telephone company's equipment, his design did not require expensive "gold plated" components to be reliable. The Distributed Network that Baran introduced was intended to route around damage. It provided connection to others through many points, not one centralized connection. Fundamental to the scheme was the division of the information into "blocks" before they were sent out across the network. That enabled the data to travel faster and communications lines to be used more efficiently. Each block was sent separately, traveling different paths and rejoining into a whole when they were received at their destination.

Selling the idea


After the publication of On Distributed Communications, he presented the findings of his team to a number of audiences, including AT&T engineers (not to be confused with Bell Labs engineers, who at the time provided Paul Baran with the specifications for the first generation of T1 circuit that he used as the links in his network design proposal). In subsequent interviews, Baran mentioned how the AT&T engineers scoffed at his idea of non-dedicated physical circuits for voice communications, at times claiming that Baran simply did not understand how voice telecommunication worked.[14]

Donald Davies, at the National Physical Laboratory in the United Kingdom, also thought of the same idea and implemented a trial network.[2][15] While Baran used the term "message blocks" for his units of communication, Davies used the term "packets," as it was capable of being translated into languages other than English without compromise.[15] He applied the concept to a general-purpose computer network. Davies's key insight came in the realization that computer network traffic was inherently "bursty" with periods of silence, compared with relatively-constant telephone traffic. It was in fact Davies's work on packet switching, not Baran's, that initially caught the attention of the developers of ARPANET at the Symposium on Operating Systems Principles in October 1967.[16] Baran was happy to acknowledge that Davies had come up with the same idea as him independently. In an e-mail to Davies, he wrote:

You and I share a common view of what packet switching is all about, since you and I independently came up with the same ingredients.[15]

Leonard Kleinrock, a contemporary working on analyzing message flow using queueing theory, developed a theoretical basis for the operation of message switching networks in his proposal for a Ph.D. thesis in 1961-2, published as a book in 1964.[17] In the early 1970s, he applied this theory to model the performance of packet switching networks. However, the representation of Kleinrock's early work as originating the concept of packet switching is disputed by other internet pioneers,[18][19][15][20] including Robert Taylor,[21] Baran[22] and Davies.[23] Baran and Davies are recognized by historians and the U.S. National Inventors Hall of Fame for independently inventing the concept of digital packet switching used in modern computer networking including the Internet.[24][25]

In 1969, when the US Advanced Research Projects Agency (ARPA) started developing the idea of an internetworked set of terminals to share computing resources, the reference materials that they considered included Baran and the RAND Corporation's "On Distributed Communications" volumes.[2] The resiliency of a packet-switched network that uses link-state routing protocols, which are used on the Internet, stems in some part from the research to develop a network that could survive a nuclear attack.[2][26]

Later work


In 1968, Baran was a founder of the Institute for the Future and was then involved in other networking technologies developed in Silicon Valley. He wrote on the subject of computer systems and privacy.[27] Baran participated in a review of the NBS proposal for a Data Encryption Standard in 1976, along with Martin Hellman and Whitfield Diffie of Stanford University.[28]

In the early 1980s, Baran founded PacketCable, Inc, "to support impulse-pay television channels, locally generated videotex, and packetized voice transmission."[27][29] PacketCable, also known as Packet Technologies, spun off StrataCom to commercialize his packet voice technology for the telephony market. That technology led to the first commercial pre-standard Asynchronous Transfer Mode product.

He founded Telebit after conceiving its discrete multitone modem technology in the mid-1980s. It was one of the first commercial products to use orthogonal frequency-division multiplexing, which was later widely deployed in DSL modems and Wi-Fi wireless modems.

In 1985, Baran founded Metricom, the first wireless Internet company, which deployed Ricochet,[3] the first public wireless mesh networking system. In 1992, he also founded Com21, an early cable modem company.[6] After Com21, Baran founded and was president of GoBackTV, which specializes in personal TV and cable IPTV infrastructure equipment for television operators.[30] Later, he founded Plaster Networks, providing an advanced solution for connecting networked devices in the home or small office through existing wiring.[31]

Baran extended his work in packet switching to wireless-spectrum theory, developing what he called "kindergarten rules" for the use of wireless spectrum.[32]

In addition to his innovation in networking products, he is also credited with inventing the first doorway gun detector.[6][33]

He received an honorary doctorate when he gave the commencement speech at Drexel in 1997.[34]



Baran died in Palo Alto, California, at the age of 84 on March 26, 2011[2][35] from complications caused by lung cancer.[26] Upon his death, RAND President James Thomson, stated, "Our world is a better place for the technologies Paul Baran invented and developed, and also because of his consistent concern with appropriate public policies for their use."[35]

One of the fathers of the Internet, Vinton Cerf, stated, "Paul wasn't afraid to go in directions counter to what everyone else thought was the right or only thing to do."[26] According to Paul Saffo, Baran also believed that innovation was a "team process" and avoided seeking credit for himself.[33] On hearing news of his death, Robert Kahn, co-inventor of the Internet, said: "Paul was one of the finest gentlemen I ever met and creative to the very end."

Awards and honors


See also



  1. ^ Paul Baran 2005 Fellow Archived 2015-01-03 at the Wayback Machine
  2. ^ a b c d e f Katie Hafner (March 27, 2011). "Paul Baran, Internet Pioneer, Dies at 84". The New York Times.
  3. ^ a b Nathan Brewer; et al. (March 28, 2011). "Paul Baran". IEEE Global History Network. New York: IEEE. Retrieved March 28, 2011.
  4. ^ Georgi Dalakov. "Paul Baran". History of Computers web site. Retrieved March 31, 2011.
  5. ^ David Ira Snyder (August 4, 2009). "Morris "Moshe" Baran (1884–1979)". Genealogy of the Baran family. Geni.com web site. Retrieved March 29, 2011.
  6. ^ a b c d "Paul Baran - Franklin Laureate Database". The Franklin Institute Awards - Laureate Database. Philadelphia, PA: The Franklin Institute. January 18, 2023. Retrieved January 10, 2024.
  7. ^ Hafner, Katie; Lyon, Matthew (1996). Where wizards stay up late : the origins of the Internet (1st Touchstone ed.). New York: Simon and Schuster. p. 54. ISBN 0-684-81201-0.
  8. ^ "Internet pioneer Paul Baran passes away". BBC News. March 28, 2011. Retrieved March 28, 2011.
  9. ^ Brand, Stewart (March 2001). "Founding Father". Wired. Vol. 9, no. 3. New York: Condé Nast Digital. ISSN 1059-1028. OCLC 433726773. Retrieved March 27, 2011. Paul Baran conceived the Internet's architecture at the height of the Cold War. Forty years later, he says the Net's biggest threat wasn't the USSR—it was the phone company Stewart Brand's interviews Paul Baran about his work at RAND on survivable networks.
  10. ^ "Paul Baran and the Origins of the Internet". RAND corporation. Retrieved March 29, 2011.
  11. ^ Paul Baran (1960). "Reliable Digital Communications Systems Using Unreliable Network Repeater Nodes". RAND Corporation Papers, Document P-1995. Retrieved March 29, 2011.
  12. ^ Paul Baran (1962). "On Distributed Communications Networks". RAND Corporation Papers, Document P-2626. Retrieved March 29, 2011.
  13. ^ Paul Baran; et al. (1964). "On Distributed Communications". Rand. Archived from the original on June 15, 2006.
  14. ^ Abell, John C (March 28, 2011). "Internet Architect Paul Baran Dies at 84". Wired. Retrieved March 29, 2011.
  15. ^ a b c d Harris, Trevor, University of Wales (2009). Pasadeos, Yorgo (ed.). "Who is the Father of the Internet? The Case for Donald Davies". Variety in Mass Communication Research. ATINER: 123–134. ISBN 978-960-6672-46-0. Archived from the original on May 2, 2022.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  16. ^ Isaacson, Walter (2014). The Innovators: How a Group of Hackers, Geniuses, and Geeks Created the Digital Revolution. Simon & Schuster. p. 237. ISBN 9781476708690.
  17. ^ Kleinrock, Leonard (1961), "Information flow in large communication nets", RLE Quarterly Progress Report (1)
  18. ^ Alex McKenzie (2009), Comments on Dr. Leonard Kleinrock's claim to be "the Father of Modern Data Networking", retrieved April 23, 2015 "...there is nothing in the entire 1964 book that suggests, analyzes, or alludes to the idea of packetization."
  19. ^ Isaacson, Walter (2014). The Innovators: How a Group of Hackers, Geniuses, and Geeks Created the Digital Revolution. Simon & Schuster. p. 245. ISBN 9781476708690. This led to an outcry among many of the other Internet pioneers, who publicly attacked Kleinrock and said that his brief mention of breaking messages into smaller pieces did not come close to being a proposal for packet switching
  20. ^ Haughney Dare-Bryan, Christine (June 22, 2023). Computer Freaks (Podcast). Chapter Two: In the Air. Inc. Magazine.
  21. ^ "Birthing the Internet: Letters From the Delivery Room; Disputing a Claim". The New York Times. November 22, 2001. Retrieved September 10, 2017. Authors who have interviewed dozens of Arpanet pioneers know very well that the Kleinrock-Roberts claims are not believed.
  22. ^ Katie Hefner (November 8, 2001), "A Paternity Dispute Divides Net Pioneers", New York Times, The Internet is really the work of a thousand people," Mr. Baran said. "And of all the stories about what different people have done, all the pieces fit together. It's just this one little case that seems to be an aberration.
  23. ^ Donald Davies (2001), "A Historical Study of the Beginnings of Packet Switching", Computer Journal, British Computer Society, I can find no evidence that he understood the principles of packet switching.[dead link]
  24. ^ "The real story of how the Internet became so vulnerable". Washington Post. Retrieved February 18, 2020. Historians credit seminal insights to Welsh scientist Donald W. Davies and American engineer Paul Baran
  25. ^ "Inductee Details - Paul Baran". National Inventors Hall of Fame. Archived from the original on September 6, 2017. Retrieved September 6, 2017; "Inductee Details - Donald Watts Davies". National Inventors Hall of Fame. Archived from the original on September 6, 2017. Retrieved September 6, 2017.
  26. ^ a b c "Internet pioneer Paul Baran passes away". BBC. March 28, 2011. Retrieved March 29, 2011.
  27. ^ a b "Baran's keynote on The Past, Present, and Future of Convergence". February 9, 1999. Archived from the original on April 15, 2012. Retrieved March 20, 2012.
  28. ^ "DES (Data Encryption Standard) Review at Stanford University - Recording and Transcript". 1976. Archived from the original on May 3, 2012. Retrieved March 20, 2012.
  29. ^ Baran, "Packetcable: A New Interactive Cable System Technology," 31st Annual NCTA Convention Official Transcript, 1982, cited in US patent 4,754,426
  30. ^ "Management Team". goBackTV web site. Archived from the original on March 21, 2011. Retrieved March 29, 2011.
  31. ^ "About Plaster Networks". Plaster Networks web site. Retrieved March 29, 2011.
  32. ^ Baran, Paul (November 9, 1994). "Keynote Talk Transcript, 8th Annual Conference on Next Generation Networks Washington, DC". EFF "GII - NII - Wireless/Cellular/Radio" Archive. San Francisco, CA: Electronic Frontier Foundation. Archived from the original on March 23, 2011. Retrieved March 29, 2011.
  33. ^ a b Jessica Guynn (March 29, 2011). "Paul Baran dies at 84; inventor helped lay foundation for Internet". Los Angeles Times. Retrieved March 29, 2011.
  34. ^ Nita Lelyveld (June 15, 1997). "Opportunity Lies In Ideas, Engineer Tells Drexel Grads Paul Baran, "the Grandfather Of The Internet" Spoke At His Alma Mater. He Received An Honorary Doctorate". The Inquirer. Philadelphia. Retrieved March 29, 2011.
  35. ^ a b "Packet switching inventor Paul Baran dies aged 84". ZDNet UK. March 29, 2011. Retrieved March 29, 2011.
  36. ^ "IEEE Alexander Graham Bell Medal Recipients" (PDF). IEEE. p. 2. Retrieved March 29, 2011.
  37. ^ "Book of Members, 1780-2010: Chapter B" (PDF). American Academy of Arts and Sciences. Retrieved May 17, 2011.
  38. ^ "The National Medal of Technology and Innovation 2007 Laureates". The United States Patent and Trademark Office. January 7, 2010. Retrieved March 31, 2011.
  39. ^ "In Memoriam: Paul Baran MS '59". UCLA Engineering web site. Archived from the original on June 11, 2011. Retrieved March 28, 2011.
  40. ^ 2012 Inductees, Internet Hall of Fame website. Last accessed April 24, 2012
Preceded by IEEE Alexander Graham Bell Medal
Succeeded by