The history of microwave communication begins with Western Union sending the first successful microwave message between New York and Pennsylvania in 1945 and continues to the present day, according to DPS Telecom. Since the invention of fiber optic cables, microwave towers are largely only used in remote areas.
The first microwave towers were designed for analogue microwave transmission, which uses physical phenomena to encode messages into a radio wave of microwave frequency. By the 1960s, the United States was completely covered by microwave relay stations. Shortly thereafter, telecommunications companies developed digital microwave transmission in order to send more complex information through the precise digital modulation of radio waves. The first digital microwave communication towers were developed for small- and medium-capacity networks in the 1970s, eventually expanding to cover the entire United States.
Modern telecommunications companies use both analogue and digital formats for microwave communication, depending on various environmental factors and conditions. Some telecommunications companies prefer to use older analogue microwave equipment to avoid the additional cost of purchasing digital equipment and retraining their staff. Although fiber optic cabling technology has rendered microwave communication almost obsolete in the telecommunications industry, analogue and digital microwave towers still operate in remote areas where installing fiber optic cabling is prohibitively expensive.