Phantom Ciruits (1 Jan 1921 Jahr – 31 Dez 1921 Jahr)
Beschreibung:
The switching of large numbers of calls was made possible through the use of phantom circuits. This allowed three conversations to take place on two pairs of wires.Zugefügt zum Band der Zeit:
Datum:
1 Jan 1921 Jahr
31 Dez 1921 Jahr
~ 12 months