chapter  20
10 Pages

Telephony

WithWilliam R. Davie

Telephony conveys voice and data between distant places by wired or wireless channels. The mobile telephone’s preeminence has ushered in new ways of thinking, not just about telephony but about how our lives have been reshaped by the mobile phone, that even the very idea of living without one seems, well, unthinkable. As technology advanced, traditional telephony became Plain Old Telephone Service (POTS). POTS would circulate human voices via copper wires that connected to an analog exchange center where multiple calls were rapidly switched to trunk and branch lines to reach their chosen destination. Telephony evolved through digital processing and the switching of telephone numbers converted to computer memory, known as the Storage Program Control. Early land-mobile telephone used a group of frequencies broadcast over a broad area, but lack of capacity limited its usefulness and kept prices too high.