During his time at the City College of New York he worked full time as an electrician, otherwise he couldn’t have financed his course of studies.
Later at MIT, he enjoyed a fulltime scholarship.
In his most important and probably best known publication, he dealt with the “queueing theory“ – the mathematical study of waiting lines.
The queueing theory was the topic of his doctoral thesis at MIT as well.
"Basically, what I did for my PhD research in 1961–1962 was to establish a mathematical theory of packet networks ..."
Along with his friend Larry Roberts he was making plans to quickly make a lot of money, so they invented among other things a counting cards system for black jack and a machine that was supposed to predict the number at roulette.
They caught the eye of the casinos’ personnel more than once so they were asked to leave the casino.
After the installation of the first IMP, UCLA became the first node of the ARPANET governed by Leonard Kleinrock.
By writing an e-mail to Larry Roberts, to ask him if he could look for his razor he had forgotten in England, Kleinrock demonstrated the potential of electronic mail for private use.
Leonard Kleinrock
born in 1946 in New York
Studied at the City College of New York and at MIT