From ‘Harmonic Telegraph’ to Cellular Phones

Bishnu Atal from Ming Hsieh Institute.

Download Dr. Atal’s Presentation

Bishnu S. Atal
University of Washington, Seattle, WA


It all started with two patents issued to Alexander Graham Bell in March 1876 and the world changed forever. Vast distances began to shrink. Soon, nobody was isolated. The invention produced a new industrial giant whose research laboratories supported the best in scientific research and engineering leading to major technical advances of the twentieth century. The desire for communication, anytime, anywhere spread fast; stationary phones connected by wires started fading away, replaced by “cellular phones” (“smart phones”) reflecting the cell structure of the wireless medium. This talk will provide a history of the telephones, starting from Alexander Graham Bell’s “harmonic telegraph” in 1876 to modern cellular phones.


Bishnu S. Atal is an Affiliate Professor in the Electrical Engineering Department at the University of Washington, Seattle, WA. He retired in March 2002 after working for more than 40 years at Lucent Bell Labs, and AT&T Labs

Dr. Atal’s pioneering research on speech coding for providing natural-sounding speech over digital devices has resulted in standards that lie at the heart of practically every mobile phone in use today. His work has enabled wireless networks to use less spectrum space and fewer towers to aid in the mass deployment of digital cellular systems. He demonstrated during the 1960s that Linear Predictive Coding “LPC” could represent the varying characteristics of human voice and encode the speech signal at a fraction of conventional bit rates . LPC quickly became the basis for military communication standards. He introduced the CELP method in 1985, and it is now used in practically all digital cellular speech standards as well as standards for digital voice communication over the Internet.

Dr. Atal is a member of the U.S. National Academy of Sciences. His many honors include the Thomas Edison Patent Award (1994) , the New Jersey Hall of Fame Inventor of the Year Award (2000), the IEEE Morris N. Liebmann Memorial Field Award (1986), the Benjamin Franklin Medal in Electrical Engineering (2003), and the 2013 IEEE Jack S. Kilby Signal Processing Medal.

Hosted by Prof. Shrikanth Narayanan, Colin Vaz, & Tanner Sorensen