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
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] including Robert Taylor,[20] Baran[21] and Davies.[22] 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.[23][24]
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][25]
In the early 1980s, Baran founded PacketCable, Inc, "to support impulse-pay television channels, locally generated videotex, and packetized voice transmission."[26][28] 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.[29] Later, he founded Plaster Networks, providing an advanced solution for connecting networked devices in the home or small office through existing wiring.[30]
Baran extended his work in packet switching to wireless-spectrum theory, developing what he called "kindergarten rules" for the use of wireless spectrum.[31]
In addition to his innovation in networking products, he is also credited with inventing the first doorway gun detector.[6][32]
He received an honorary doctorate when he gave the commencement speech at Drexel in 1997.[33]
Death
Baran died in Palo Alto, California, at the age of 84 on March 26, 2011[2][34] from complications caused by lung cancer.[25] 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."[34]
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."[25] According to Paul Saffo, Baran also believed that innovation was a "team process" and avoided seeking credit for himself.[32] 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."
Fellow of the Computer History Museum (2005) "for fundamental contributions to the architecture of the Internet and for a lifetime of entrepreneurial activity."
^Brand, Stewart (March 2001). "Founding Father". Wired. Vol. 9, no. 3. New York: Condé Nast Digital. ISSN1059-1028. OCLC433726773. 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.
^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.
O'Neill, Judy E. (March 5, 1990). "Oral history interview with Paul Baran". Minneapolis, MN: Charles Babbage Institute. Retrieved March 31, 2011. A 44-page transcript in which Baran describes his working environment at RAND, his initial interest in survivable communications, the evolution of his plan for distributed networks, the objections he received, and the writing and distribution of his eleven-volume work, On Distributed Communications. Baran discusses his interaction with the group at ARPA who were responsible for the later development of the ARPANET.
Ryan, Patrick S. (June 1, 2005). "SSRN-Wireless Communications and Computing at a Crossroads: New Paradigms and Their Impact on Theories Governing the Public's Right to Spectrum Access". Journal on Telecommunications & High Technology Law. 3 (2). Boulder, CO: University of Colorado Law School: 239–274. ISSN1543-8899. OCLC66137086. SSRN732483. This describes Paul Baran's development of packet switching and its application to wireless computing.
Апшеронський національний паркAbşeron Milli Parkı Місцеположення парку на карті 40°17′00″ пн. ш. 50°21′33″ сх. д. / 40.2836111100277776131° пн. ш. 50.3594444400277723° сх. д. / 40.2836111100277776131; 50.3594444400277723Координати: 40°17′00″ пн. ш. 50°21′33″ сх. д. / 40.2836111100277776131°…
Scottish association football player (born 1978) For the bishop of the Episcopal Diocese of Atlanta, see J. Neil Alexander. For the British zoologist, see Neill Alexander. Neil Alexander Alexander with Rangers in the 2008 UEFA Cup FinalPersonal informationFull name James Neil Alexander[1]Date of birth (1978-03-10) 10 March 1978 (age 45)Place of birth Edinburgh, ScotlandHeight 1.85 m (6 ft 1 in)[2]Position(s) GoalkeeperYouth career Edina HibsSenior career*Years…
Đừng nhầm lẫn với Nakamura Yuichi (diễn viên). Đây là một tên người Nhật; trong tiếng Nhật họ và tên được viết theo thứ tự Á Đông (họ trước tên sau): họ là Nakamura. Nakamura YuichiTên khai sinhNakamura Yūichi (中村 悠一)Sinh20 tháng 2 năm 1980 (43 tuổi)Aji, Kagawa, Nhật BảnNghề nghiệpdiễn viên lồng tiếngNăm hoạt động2001 - nayVai diễn đáng chú ý Macross Frontier trong vai Saotome Alto CLANNAD tron…
Maurice Wertheim (* 16. Februar 1886 in New York; † 27. Mai 1950 in Cos Cob, Connecticut) war ein US-amerikanischer Bankier und Philanthrop. Maurice Wertheim als Co-Direktor der Theatre Guild (1923) (dritter von rechts) Leben Maurice Wertheim entstammte einer wohlhabenden jüdischen Familie aus New York. 1906 erzielte er einen Bachelor- und 1907 einen Master-Abschluss an der Harvard University. 1907 wurde er Vizepräsident der von seinem Vater Jacob Wertheim geleiteten United Cigar Manufacturi…
Alvin and the Chipmunks:The Road ChipPoster resmiSutradara Walt Becker Produser Janice Karman Ross Bagdasarian, Jr. Ditulis oleh Randi Mayem Singer Adam Sztykiel Berdasarkan Alvin and the Chipmunksoleh Ross Bagdasarian Sr. The Chipettesoleh Janice Karman Pemeran Jason Lee Tony Hale Kimberly Williams-Paisley Josh Green Justin Long Matthew Gray Gubler Jesse McCartney Kaley Cuoco Anna Faris Christina Applegate Penata musikMark MothersbaughSinematograferPeter Lyons CollisterPenyuntingRyan Fols…
Lesung im Theater Lübeck aus Anlass des Lübecker Literaturtreffens 2013; von links Feridun Zaimoglu, Tilman Spengler, Eva Menasse und Sherko Fatah Das „Lübecker Literaturtreffen“ ist der von Günter Grass bestimmte Titel eines am 5. Dezember 2005 gegründeten deutschen Autorenzirkels. Die zunächst in Anlehnung an die Gruppe 47 „Lübeck 05“ titulierte Vereinigung setzt sich aus bekannten deutschsprachigen Schriftstellern zusammen. Ziel ist es laut Grass, das „Bedürfnis nach politis…
2007 Indian filmUnnale UnnaleDirected byJeevaWritten byJeeva Srinath Sahadevan (uncredited) S. Ramakrishnan (dialogues)Produced byV. RavichandranStarringVinay RaiSadhaTanishaCinematographyJeevaEdited byV. T. VijayanMusic byHarris JayarajProductioncompanyAascar Film[2]Release date 14 April 2007 (2007-04-14) [1]Running time147 minutesCountryIndiaLanguageTamil Unnale Unnale (transl. Because of You) is a 2007 Indian Tamil-language romantic musical film.The movie …
Pour les articles homonymes, voir Damien. Cet article est une ébauche concernant les chrétiens d'Orient. Vous pouvez partager vos connaissances en l’améliorant (comment ?) selon les recommandations des projets correspondants. Damien Ier de JérusalemDamien Ier de JérusalemFonctionPatriarche grec-orthodoxe de JérusalemPatriarcat orthodoxe de Jérusalem15 août 1897 - 14 août 1931BiographieNaissance 10 juillet 1848MarathókambosDécès 14 août 1931 (à 83 ans)JérusalemNom …
Fachada del edificio El edificio de la Caixa d'Estalvis de Vila-real está situado en los números 52 y 54 de la calle Mayor San Jaime de Villarreal (Castellón), España. Corresponde al proyecto del arquitecto catalán Eugenio Pedro Cendoya de 1930 para la sede de la entonces floreciente Caja de Ahorros de Villarreal. Creada unos años antes, dado el crecimiento que experimenta esta Caja, y su consolidación como apoyo a las actividades agrarias, decide construir en 1930 una sede digna que resp…
Edificio Petroperú LocalizaciónPaís PerúUbicación Lima, PerúCoordenadas 12°05′52″S 77°01′30″O / -12.0979, -77.0249Información generalUsos OficinasEstilo BrutalismoPrimera piedra 1969Construcción 1973Propietario Estado PeruanoAlturaAltura de la azotea 82 m.Detalles técnicosPlantas 22Diseño y construcciónArquitecto Walter WeberhoferDaniel Arana Ríos[editar datos en Wikidata] El Edificio Petroperú es un edificio ubicado en el distrito de San Is…
17th major version of the macOS operating system macOS 11 redirects here. For the 10.11 release of macOS, see OS X El Capitan. macOS Big SurVersion of the macOS operating systemmacOS Big Sur's desktop in light appearanceDeveloperApple Inc.OS family Macintosh Unix, based on Darwin (BSD) Source modelClosed, with open source componentsGeneralavailabilityNovember 12, 2020; 3 years ago (2020-11-12)[1]Latest release11.7.10 (20G1427)[2] (September 11, 2023;…
Опис файлу Опис Фесик Микола Кирилович. міський голова Броварів Джерело з книги Бровари - мій дім Час створення 1970-ті Автор зображення невідомо Ліцензія Ця робота є невільною — тобто, не відповідає визначенню вільних творів культури. Згідно з рішенням фонду «Вікімедіа»…
American basketball player (born 1983) For the actor, see Dan Ewing. Daniel EwingEwing with Asseco Prokom in 2009Personal informationBorn (1983-03-26) March 26, 1983 (age 40)Milton, FloridaNationalityAmericanListed height6 ft 3 in (1.91 m)Listed weight185 lb (84 kg)Career informationHigh schoolWillowridge (Houston, Texas)CollegeDuke (2001–2005)NBA draft2005: 2nd round, 32nd overall pickSelected by the Los Angeles ClippersPlaying career2005–2019PositionShooting g…
Frankfurt (Main) Ostendstraße Bahnsteig (nach der Umgestaltung 2016)Bahnsteig (nach der Umgestaltung 2016) Daten Bauform Tunnelbahnhof Bahnsteiggleise 2 Abkürzung FOST IBNR 8002058 Preisklasse 3 Eröffnung 1990 bahnhof.de Frankfurt (Main) Ostendstraße-1038930 Lage Stadt/Gemeinde Frankfurt am Main Ort/Ortsteil Ostend Land Hessen Staat Deutschland Koordinaten 50° 6′ 41″ N, 8° 41′ 51″ O50.1113898.6975Koordinaten: 50° 6′ 41″ N, 8° …
1991 video game 1991 video gameSuper SkweekDeveloper(s)LoricielPublisher(s)LoricielDesigner(s)Laurent ArditiStephane DucassePlatform(s)Amiga, Atari ST, Lynx, MS-DOS, Amstrad CPC, Game Gear, PC Engine, iOSRelease1991Genre(s)PuzzleMode(s)Single-player, multiplayer Super Skweek is a puzzle game developed and published by the French company Loriciel. The game was released on multiple platforms in the early 1990s as a follow-up to 1989's Skweek (released as Slider in 1991 in the United States).[1…
青蜂俠The Green Hornet台灣版電影海報基本资料导演米歇·龔德里监制Neal H. Moritz编剧塞斯·羅根伊凡·戈博剧本塞斯·羅根埃文·戈德堡原著青蜂俠George W. TrendleFran Striker作品主演塞斯·羅根克里斯多夫·華茲愛德華·詹姆斯·歐蒙周杰倫湯姆·威金森卡麥蓉·狄亞配乐詹姆斯·紐頓·霍華摄影約翰·史瓦茲剪辑Michael Tronick制片商Original Film片长119分鐘产地 美國语言英語上映及发行上映日期…
Art curator This article is an orphan, as no other articles link to it. Please introduce links to this page from related articles; try the Find link tool for suggestions. (April 2023) Ajayya KumarBornCherpu, Thrissur, KeralaNationalityIndianEducationDoctorate in ManagementAlma materInstitute of Cost Accountants of India, Institute of Management Accountants USA, American Academy of Financial ManagementOccupation(s)Art curator, Author, COOAjayya Kumar is a COO, Author, Management Thinker &…
Film Titel Das Dschungelbuch Originaltitel The Jungle Book Produktionsland USA Originalsprache Englisch Erscheinungsjahr 1967 Länge 75 Minuten Altersfreigabe FSK 0 Stab Regie Wolfgang Reitherman Drehbuch Larry Clemmons,Ralph Wright,Ken Anderson,Vance Gerry Produktion Walt Disney Musik Filmmusik:George BrunsLieder:Robert B. ShermanRichard M. ShermanTerry GilkysonOrchestration:Walter Sheetsdeutsche Liedtexte:Heinrich Riethmüller Schnitt Tom Acosta,Norman Carlisle → Synchronisation → Chr…
Public schoolPalm Desert High SchoolLocation74910 Aztec Road,Palm Desert, California 92260InformationTypePublicEstablished1986PrincipalSarit Saig [1]Enrollment2,090 (2019-20)[2]Color(s) MascotAztecRivalLa Quinta High SchoolNewspaperThe SpearYearbookDesert ReflectionsWebsitepdhs.dsusd.us Palm Desert High School is a secondary school located in Palm Desert, California. The school is a part of the Desert Sands Unified School District. Academics Palm Desert offers numerou…