Popularly, a telephone is known as a phone and it is a device that has changed the way telecommunications has affected our lives. It receives and transmits sound from one place to other place. This device works on point-to-point communication system whose standard function is allowing two persons to talk to each other, despite the fact that they are separated by large distance. Today, a telephone has become the most common household appliance around the world.
The appliances make use of a microphone, which converts sound waves to electrical signals and the signals go through a telephone network and again the electrical signals are converted to original sound waves by an earphone, which is associated with the handset. The network of telephone comprised of a worldwide net of undersea telephone cables, communications satellites, cellular networks, microwave transmission, fiber-optic cables, and telephone lines, which are connected by some switching centers, permits a telephone to communicate with another telephone. Similar to names of persons, all telephones have unique numbers called telephone numbers.
History of Telephone
In 1876, a well known scientist called Alexander Graham Bell invented the telephone. At that that, the technology was simple communication system means information was allowed only from one side at a time. Later many enhancements were made to telephone and at last full-duplex system were invented, which allowed the information to travel from both sides at a time. And currently, all modern telephones are using this technology.
Types of Telephones
The basic telephones are of three types. They are listed below.
• Traditional land phone,
• Cordless phone, and
• Cellular or mobile phone.
Coming to traditional land phone, it is wired connection phone and it is fixed at one place. It is not transportable and both handset and number typing pad connected by a cable. This is the appearance of land phone and you can see it from beside picture.
Talking about cordless phone, it is similar to a land phone and the only difference between then is the cordless phone doesn’t have wired connection. It is a wireless phone and it is bulkier than cellular phone. It is slightly expensive than traditional land phone. One common thing of land phone and cordless phone is numbers of both phones have to be taken from telephone exchange.
Ultimately, a cellular phone (usually called a cell phone) is entirely different from land phone and cordless phone. One big difference is it doesn’t have any relation with telephone exchange. It is very small in size and taking it while travelling is very easy. It is adjustable in pocket of a man and it works with an in-built battery.
Working of a Telephone
Theoretically, working of telephone is very simple. But, practically it is very complex. Since a telephone should work around the world, it needs a big network.
After dialing number from at one telephone, then the request of calling will travel to telephone exchange. From there, the request will do to destination telephone. If the destination telephone is busy, it gives the same reply to requested telephone. In other case, it stimulates the destination phone and you can hear ringing sound from the requested telephone receiver.
After picking up the destination phone, the sounds produced by the users will converts into electrical signals at one end and converts back to sound signals at receivers. This is the working of a telephone.