His family moved to the United States on May 11, 1928,[4] settling in Boston and later in Philadelphia, where his father, Morris "Moshe" Baran (1884–1979), opened a grocery store.

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.

[8] 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.

In Baran's words, unlike the telephone company's equipment, his design did not require expensive "gold plated" components to be reliable.

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.

However, the representation of Kleinrock's early work as originating the concept of packet switching is disputed by other internet pioneers,[17][18][14][19] 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.

[26] 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.

[27] In the early 1980s, Baran founded PacketCable, Inc, "to support impulse-pay television channels, locally generated videotex, and packetized voice transmission.

[5] After Com21, Baran founded and was president of GoBackTV, which specializes in personal TV and cable IPTV infrastructure equipment for television operators.

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

[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.