The planet ‘s first wireless telephone conversation happened in 1880, when Alexander Bell and Charles Sumner Tainter invented and patented the photophone, a telephone that conducted sound dialogues wirelessly over-modulated rays (which are narrow projections of electromagnetic waves). In that era that is distant, lasers had not been envisioned in science fiction and when utilities did not yet exist to provide electricity, there have been no practical applications for their invention, which was highly limited by the availability of both sunlight and weather that is good. Similar to Free Space optical communication, the telephone additionally necessitated a clear line of sight between its transmitter and its receiver. It could be a few decades before their first practical applications were discovered by the principles of the telephone in military communications and after in fiberoptic communications http://en.wikipedia.org/.
The term “radio receiver” came into public use to make reference to a radio receiver or transceiver (a dual purpose receiver and transmitter apparatus), establishing its use in the area of wireless telegraphy early on; today the phrase can be used to describe modern wireless connections such as in mobile networks and wifi broad Band Internet. Additionally it is used in a general sense to reference almost any process that is implemented without the usage of wires, for example “wifi remote control” or “wireless energy transfer”, no matter the specific technology (e.g. radio, infrared, ultrasonic) used. Guglielmo Marconi were granted the 1909 Nobel Prize for Physics for his or her contribution to wireless.
Free Space optical communication (FSO) is an optical communication technology that uses light propagating in free space to wirelessly transmit information for telecommunications or computer-networking. “Freespace” indicates the rays go through the open-air or outer space. This contrasts with other communication technologies that use rays traveling through transmission lines for example optical fiber or dielectric “light pipes”.
The technology is useful where connections are due to other considerations or high prices. For instance free space optical links are employed in towns between office blocks which aren’t wired for networking, where the price of running cable through the building and beneath the road will be prohibitive.