In 1947, Bell Laboratories in the United States devised a system by which a particular geographic territory could be divided in to a number of cells, each serving as a base station with its own transmitter and receiver. The application ensured that the spectrum was not wasted. This was the beginning of modern cellular technology. In 1973, Motorola displayed the first portable phone, which weighed two kilograms. In 1979, NTT launched car phones on a pilot commercial scale in Tokyo.