Playin' on the Radio

Even before wireless technologies like the telegraph became a widespread phenomenon in the late 19th Century, Nikola Tesla was already well aware of the possible entertainment purposes of Radio technology. In 1898, he showcased an early example of a radio controlled boat, which utilized pre-'programmed' circuits within the boat which could execute commands via radio frequency. This is one of the earliest examples of a radio controlled device. 

Although radio technology was developed in World War I, it was not until World War II that extensive research was put into utilizing it for war. The Germans were highly interested in using radio to control missiles, the British and United states too, were very keen on radio development, but this technology was not used extensively in weaponry due to the unstable results of their experiments. 

The radio control systems of the 1940s were generally electromechanical in nature, The radio transmitter would transmit different frequencies in response to the movements of a control sticks, such as on off signals. This would later, in commercial RC vehicles develop to accommodate other commands such as right, left, neutral as well as different speeds. 

It was the advent of transistors  in the 1960s, which allowed low voltage equipment to be made, and thus the option of using RC in small models were made feasible. Although RC vehicles first gained popularity in the UK and US, by the 1970s Japanese RC controlled vehicles such as those from Tamiya were soon gaining widespread popularity too. 

In later years, Infrared (IR) would also be used in the controlling of toy vehicles, especially that of IR controlled Aeroplanes, which could fly and do all sorts of complicated maneuvers. The original Furby of 1998 used infrared ports to communicate with each other. The Furbies of 2012 onward however, now use high-frequency sound coding to communicate with each other, as well as cell phones, since infrared is no longer a popular phone feature. HFS is increasingly being used in mobile and computer devices to transmit information.