Wire and Wireless Systems in Telecommunications
Man has ever been trying to express his thought through various means, methods and techniques. Communication has been an inbuilt capability of humans. History transpires numerous necessity oriented tactics that have been used by man for communication. He is still using these techniques. Initially, he was bound to serve his purpose through the medium of nature since he opened eye in its lap and there was no other techno logy or resources available for this purpose.
Historical Background: Relationship to the Needs of the Society
Native Americans, in ancient times, used a distinctive technique for communication called smoke signals. This may be termed as the first and foremost means of signal based communication. In this technique, columns or puffs of smoke were dispatched into the air in different shapes and frequencies on encoding side. On the other decoding side, signals would be perceived as desired by the signaler.
These smoke signals cannot be declared or rated precisely a full language, but were typically used as short signals of communication. Some of the standard signals even retain information today. For example, one puff of smoke dispatched into the air was supposed to signal intended viewer's attention. While, on the other hand, two puffs meant nothing dangerous and every thing is all right. Contrary to this, three puffs signal hazard, call for aid, or merely some expected trouble.
The smoke was produced by putting together green branches or leaves of grass into the fire. In this practice, blankets are used to direct the smoke puffs. Beside this, important events were also discernible by smoke signals. These events constitute war, birth, marriage or death. There were also light and heavy signals in vogue, each meaning variegated things. One meant good event, while the other meant bad...