In the 1980s, Marian Croak began developing technology for sending voice over the internet, helping advance Voice over Internet Protocol

In the early 1980s, only a few could imagine internet voice calls or even face-to-face phone conversations with just a tap. The internet was far from being part of people’s lives. Most people were making phone calls through the traditional telephone system, and computers back then worked as an independent system of communication, used for separate technologies.

No one could imagine that one day it was going to become possible to call someone or to hold a conversation via the internet. Marian Croak saw that possibility in the technology much earlier. She joined Bell Labs, the research arm of AT&T, in 1982 and started believing that the internet would gain the ability to transmit voice messages, just as it was transmitting the data itself. Instead of using standard phone lines to communicate, Croak began to develop ways of transforming voice into digital signals sent through the internet. According to the National Inventors Hall of Fame, her work resulted in creating the technology of voice transmission through the internet (VoIP).

The journey and its challenges


The idea was simple, but making it work reliably was a challenge. In the 1980s, the internet was not equipped to transmit live voice calls. The packets could arrive in the wrong order, be late, or even never come at all. Croak thought that these problems could be solved. She and her colleagues experimented with converting voice into packets of digital data and transmitting them through Internet Protocol (IP) networks instead of conventional telephone systems. The goal was not just to demonstrate that IP calling could work but to make it reliable for everyday use.

The process took years of testing and refinement. Many engineers were doubtful about the idea since telephone communication systems were already highly reliable. Convincing people that the Internet-based communication systems would be equally reliable was as difficult as tackling technical issues. Croak, nevertheless, went on working on the development of the technology until it was proven to be realistic for use.

Building technology that could grow

Croak’s advancement of techniques enhanced the dependability and execution of Voice over Internet Protocol systems, making them functional in much wider networks. Throughout her career at AT&T, which lasted for 32 years, she received over 200 patents, a sufficient number of which were directly related to VoIP technology and its performance. Moreover, her contribution helped AT&T integrate traditional voice engineering with Internet protocol engineering as communication through the Internet started to take shape.

As the Internet continued to develop in the 1990s, the development that Croak started ten years earlier now became more important. For a reliable Internet calling system, simply sending voice from one computer to another was not enough. The networks needed to accommodate thousands and millions of calls happening simultaneously while maintaining clear sound quality.

Croak helped develop the methods that provided better performance and reliability for Voice over Internet Protocol (VoIP) systems and allowed them to work over a larger network. During her 32 years at AT&T, she was awarded over 200 patents, many of which concern VoIP and network performance improvement. Her work has assisted AT&T in merging traditional voice engineering with Internet Protocol engineering, which made sending voice over the Internet possible. The discovery was highly praised as Internet communication gradually became a practical reality.

An everyday technology

Modern communication platforms rely on Voice over Internet Protocol. A video meeting or voice call with coworkers or family across different countries can happen within seconds using internet connections instead of traditional telephone circuits.

VoIP enables this convenience, which is currently used in communication systems. With VoIP, users do not need separate telephones for each call because voice data is changed into a digital signal that can be transmitted over the internet and processed at the other end. The advancement of broadband internet technology has led to big changes in using the same technique for transmitting videos as well. Voice and video could travel together across the internet, allowing online meetings and video chats to become a routine part of everyday life. According to the U.S. Patent and Trademark Office, her work helped lay the foundation for many modern virtual communication technologies, including online audio and video calls.