Category Self Image & Branding

Today, the postman delivers letters to every home. In the past though, the post was a privilege enjoyed only by kings and emperors. They used runners to carry messages to other rulers and to their commanders during times of war. A king would have a message inscribed on a clay tile and send a runner to take it to anotherHowever, the ancient Egyptians though did have a kind of postal system and so did the ancient Chinese. The early postal systems depended upon post houses that served the carriers of messages or mounted messengers. The Romans created the most highly developed and dependable system in the ancient world. This system could deliver messages 270 kilometers in 24 hours

You can say that wireless communication is communication that requires no wires! To put it more accurately, it is communication that takes place through the air, using radio waves or infrared light. There is no need for cables or telephone lines for wireless communication. Wireless communication systems use devices called transmitters to generate radio waves. A microphone or other device converts sound or other data into electrical impulses. The transmitters change the impulses into radio signals that can be sent across great distances. Radio receivers pick up these signals, and turn them back into the original sound or messages.Wireless communication has also become a part of our daily life. It is used in our radios, televisions, mobile phones, remote controls and security systems. Wireless communications are a rapidly growing segment of the communications industry, and have mind boggling applications for the future.

You must have heard of planes and ships being located by radar, but what exactly is radar? It is a scientific method to detect and locate moving or fixed objects by using radio waves. In fact, the full form of the word ‘radar’ is ‘radio detection and ranging’. Radar can detect the distance, height, direction and speed of objects that are much too far for us to see. It does this by sending radio waves towards an object, and receiving the waves that are reflected from an object. The time it takes for the reflected waves to return from an object tells us how far away it is. The direction from which the reflected waves return tells us where the object is located.Radar can find anything from tiny insects to huge mountains. It is extremely useful as it works at night too and is not affected by the weather. In fact, it is used by weather departments to make forecasts. Radar is used to control the movement of aircraft and ships, and even to catch your father if he is over speeding!

A ringing cell phone can be a nuisance to others in some places like a theatre or at important meetings. A pager is very useful then, because it alerts you that someone is trying to contact you by vibrating silently. How does a pager work? If you want to page your friend, you must first dial the number of his paging service provider. You will then be connected to a computerized terminal which instructs you to key in your telephone number, and then press the ‘star’ key on your phone to complete the message. The paging terminal routes the signal to a radio transmitter. If your friend’s pager is switched on, and within the radio transmitters range, it will recognize the coded signal sent by the radio transmitter. The pager then converts the signal into data, and alerts your friend with a beep or vibration. You number will be displayed on his pager, and he can then call you back whenever it is convenient to him.

You can walk into nearly any office today, big or small and you will find a fax machine. Connected to a normal phone line, a fax machine allows you to copy send and receive documents instantly. The word ‘fax’ is the short form for ‘facsimile’ which means ‘an exact copy’. The fax machine works like a combination of a telephone and photocopier. The user places the paper with a picture or message into the document feeder of the sending machine. He then dials the telephone number of the receiving fax machine.An optical scanner in the sending machine records the variations between light and dark areas of the document. These variations are recorded as dots arranged in a series of rows or columns. A photo-electric cell converts the dots into electronic impulses which are transmitted through telephone wires to the receiving machine.The receiving machine converts the electrical impulses back into a series of dots. The decoded signal is sent to the print mechanism of the receiving fax. A duplicate of the original picture or message appears like magic!

Our lives have been completely changed with the invention of the telephone. No one person can really be credited with inventing it, though Alexander Graham Bell is acknowledged as the father of the modern telephone. Simply described, the telephone is a system which converts sound, specifically the human voice, to electrical impulses of various frequencies. These electrical frequencies are then turned back to a tone that sounds like the original The foundation for today’s telephone was laid in 1831, when an Englishman Michael Faraday, proved that vibrations of metal could be converted to electrical impulses. A practical telephone was actually invented independently by two men working in the United States, Elisha Gray and Scottish – born Alexander Graham Bell. Incredibly, both men filed for a patent on their designs at the New York patent office on February 14, 1876, with Bell beating Gray by only two hours!According to the famous story, the first fully intelligible telephone call occurred on March 6, 1876, when Bell, in one room, called to his assistant in another room. ‘Come here, Watson, I want you.’ Watson heard the request through a receiver connected to the transmitter that Bell had designed.