AT&T Archives: Single Sideband, a 1977 film about microwave transmission

See more from the AT&T Archives at This short film, made by Bell Laboratories in 1977, gives a basic overview of what single-sideband transmission consists of, and why it was implemented in the phone system that year. Single sideband transmission allowed the Bell System to carry a greater number of data, voice, and broadcast signals along the microwave network. Single Sideband transmission was first recognized during the first overseas radio transmission tests conducted by the Bell System in concert with the U.S. Navy, in 1915. These tests took place at the U.S. Naval Radio Station in Arlington, Virginia, and were overseen by Harold D. Arnold of Bell Telephone (Bell Laboratories was formed later, in 1925). The tests built on scientific work by Raymond A. Heising and John Renshaw Carson at Bell Telephone and Western Electric. The first cross-country microwave network call was placed in 1951. By 1977, the Bell System’s microwave network carried 70