AT&T Labs developed car phones in the 1940s and continued to seek improvements. But until recently mobile telephones were rare, limited by a lack of available communications channels. The big breakthrough came when AT&T Labs divided wireless communications into a series of cells, then automatically switched callers as they moved so that each cell could be reused. This led to the development of cellular phones and made today's mobile communications possible.

For their pioneering work in cellular telephony, AT&T Labs researchers Richard Frenkiel and Joel Engles earned the National Medal of Technology. Cellular telephony has spawned a multibillion-dollar industry and has freed tens of millions of people, both at home and at work, to communicate anywhere, any time.