The May/June 1969 issue of Bell Laboratories’ Record included a look back at the technology that had been developed by the research lab since 1956 in its quest to make a practical videophone.

One of the biggest challenges was getting a videophone to work within existing infrastructure. The telephone companies had already laid out telephone lines to homes and offices across the U.S.

There was no desire to roll out any new infrastructure, so the goal was to use those existing lines and supply each home and exchange with new hardware for sending and receiving video messages in real time.