The concept of a mobile phone was a century old. It had its tentative beginings in the concept of a "car phone" as early as 1910 when Lars Magnus Ericsson, the founder of the eponymous Swedish telephone company, attempted to build a telephone into his vehicle and connect it to the overhead telephone lines. The technology was based on the idea that the voice of the speaker at either end could be transformed into radio waves, which could journey through the air; once they hit a receiver at a nearby base station, the latter used the mainline telephone network to re-route the call. However, the major requirement for this transmission was the radio spectrum, which was limited. As a result there was no further development of the concept for the next four decades.