Leonard Kleinrock

June 13, 1934

Brief Biography

A critical figure in the development of the internet, Leonard Kleinrock was born in Harlem, New York City. At six years old, Kleinrock stumbled upon an advertisement in a comic book that inspired him to build a crystal radio out of household items and other knickknacks. Enchanted by creating something that could receive and transmit messages across the air, he developed a lifelong passion for electronics engineering and communications technology. Kleinrock attended the Bronx High School of Science, going on to study electrical engineering at the City College of New York. Unable to pay the twelve dollars per semester tuition at CCNY, he was employed full-time in electronics and took evening classes. This gave him the opportunity to study alongside and underneath other professionals who knew the in-and-outs of electronics in action. Kleinrock went on to pursue graduate degrees from the Massachusetts Institute of Technology. At the MIT Lincoln Laboratory, he worked under Ken Olsen.

Kleinrock wanted to study under the best professors at MIT while at the same time finding a dissertation subject that allowed for groundbreaking work . He went on to research message delay in communication networks under the supervision of Edward Arthurs with the father of information and coding theory, Claude Shannon, on his committee; he received his PhD in 1963. After obtaining a doctoral degree, Kleinrock joined the faculty at the University of California, Los Angeles where he has since remained. Even though the telecommunications industry took a disinterested stance towards Kleinrock’s network developments in the 1960s, he continued his research. In 1969, the environment changed when the Advanced Research Project Agency of the United States Department of Defense began funding the early development of a packet-switching network, ARPANET. ARPANET, which incorporated packet-switching networks developed by Kleinrock and Paul Baran, was the first network to implement the Internet protocol suite.

Kleinrock began working on queueing systems in 1960 and wrote a two volume collection, published in 1975 and 1976. The second volume on computer applications of queueing systems was jointly awarded that year’s Frederick W. Lanchester Prize for best publication in operations research.  The prize committee recognized Kleinrock as an “artist” in queueing theory application, pulling together an enormous quantity of material into a single collection. His employment of queueing theory in computer systems design was correctly predicted to surpass in importance its original use in telecommunications. Kleinrock went on to publish three more books on the subject.

In 1999, Kleinrock received the Institute for Operations Research and the Management Sciences (INFORMS) President’s Award. Beginning with Kleinrock’s first paper on packet switching theory in 1961, the citation from INFORMS President Thomas L. Magnanti outlined and celebrated his four decade career as a leading network scientist, benefiting the many fields within operations research and global society as a whole. Beyond his role in the development of ARPANET and his significant publications contributions to queueing theory, Kleinrock was lauded for the nearly fifty doctoral graduates he has supervised, positively influencing future generations of computer network developers and scholars.

Kleinrock is a member of the National Academy of Engineering and the American Academy of Arts and Sciences.  Beyond his many other honors, Kleinrock is a recipient of the National Medal of Science, the National Academy of Engineering Charles Stark Draper Prize, the L.M. Ericsson Prize, and the Marconi Prize,  along with seven honorary degrees."

Other Biographies

Wikipedia Entry for Leonard Kleinrock

Eyerys. People: The Internet And Leonard Kleinrock. Accessed April 30, 2015. (link)

Internet Hall of Fame. Blog: Leonard Kleinrock, the TX-2 and the Seeds of the Internet. Published October 1, 2012. Accessed April 30, 2016. (link

The University of California, Los Angeles Computer Science. Leonard Kleinrock: Personal History/Biography. Accessed April 30, 2015. (link


City College of New York, BEE 1957

Massachusetts Institute of Technology, MS 1959 

Massachusetts Institute of Technology, PhD 1963 (Mathematics Genealogy)


Academic Affiliations
Non-Academic Affiliations
  • IBM
  • Linkabit Corporation
  • Nomadix, Inc. 
  • TTI/Vanguard

Key Interests in OR/MS


Oral Histories

Big Think. The Internet Utters Its First Word. Video. Recorded May 14, 2010. Accessed April 30, 2015. (video)

Leonard Kleinrock (1990) Interview by Judy O'Neill. April 3. Transcript. Los Angeles, CA. Charles Babbage Institute: Minneapolis, MN. (transcript)

Leonard Kleinrock (2004) Interview by John Vardalas. Transcript. IEEE History Center: Hoboken, NJ. (transcript)

Leonard Kleinrock (2009) Interview by Ira Flatow. October 30. National Public Radio. (audio)

UCLA (2011) My Work and My Life - Leonard Kleinrock. Youtube. Uploaded June 24. Accessed June 15, 2015. (see embedded YouTube video below)

UCLA (2009) The First Internet Connection, with UCLA's Leonard Kleinrock. Youtube. Uploaded January 13. Accessed June 15, 2015. (see embedded YouTube video below)


Awards and Honors

Frederick W. Lanchester Prize 1976

Marconi Prize 1986

IEEE Computer Society Harry Goode Memorial Award 1996

INFORMS President's Award 1999

National Academy of Engineering Draper Prize 2001

Institute for Operations Research and the Management Sciences 2002

National Medal of Science 2007

Dan David Prize 2010

IEEE Alexander Graham Bell Medal 2012

BBVA Foundation Frontiers of Knowledge Award in the Information and Communication Technologies 2014

Selected Publications

Kleinrock L. (1964) Communication Nets; Stochastic Message Flow and Delay. McGraw-Hill: New York.

Kleinrock L. (1967) Optimum bribing for queue position. Operations Research, 15(2): 304-318.

Kleinrock L. (1975) Queuing Systems, Volume I: Theory. Wiley Interscience: New York.

Kleinrock L. (1976) Queueing Systems, Volume II: Computer Applications. Wiley Interscience: New York.

Gail R. & Kleinrock L. (1982) Solutions Manual for Queueing Systems,Volume I: Theory. Technology Transfer Institute: Los Angeles.

Kleinrock L. & Scholl M. (1983) On the M/G/1 queue with rest period and certain service-independent queueing disciplines. Operations Research, 31(4): 705-719.

Gail R. & Kleinrock L. (1986) Solutions Manual for Queueing Systems,Volume II: Computer Applications. Technology Transfer Institute: Los Angeles.

Kleinrock L. & Levy H. (1988) The analysis of random polling systems. Operations Research, 36(5): 716-732.

Gail R. & Kleinrock L. (1996) Queueing Systems: Problems and Solutions. John Wiley & Sons: New York.  

Kleinrock L. (2002) Creating a mathematical theory of computer networks. Operations Research, 50(1): 125-131. (link)