First Phone Data Communication

1249 Words 5 Pages
Task 1

Phones

The first phone data communication was invented by Alexander Graham Bell in 1874-1876. But the very first person to be able to convey sounds over a taut extended wire by mechanical vibrations was Robert Hooke in 1667 so it’s the culmination of work done by many individuals until Alexander Graham Bell created a telephone.
The earlier development is when sound waves are carried as mechanical vibrations along the string or wire from one diaphragm to the other. A very good example is the tin can telephone.
In 1876, Alexander Graham Bell used what he called a ‘liquid transmitter’. When Bell shouted into the open end of the cone, his voice made the parchment vibrate, so the needle moved slightly in relation to a contact in the cup.
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Every bit is sent one after another and there are no gaps in transmission. Maintaining the timing is essential because there is no start and stop bits and no gaps. The accuracy is depending on the receiver to keep an accurate count of the bits as the come in. The clock is embedded in the data stream encoding. The sender and the receiver provides a separate clock lines so that the sender and the receiver are always in synchronization during a frame transmission. The synchronous signaling pulses on one signal line and indicates when another bit of information is ready on the other signal line. A pulse from the local clock indicates when another bit is ready so this means that the synchronous transmissions uses and external clock. The stream of data that is to be transferred is encoded and sent on one line and a pulse of voltage which is often called the clock or strobe is put on the other line, this tells the receiver about the beginning and the ending of each bit or …show more content…
But one of the drawbacks is that it has a high or large overhead which means that each byte carries at least two extra bits and therefore it has a 25% loss of line. Asynchronous transmission is also slow because of the increased number of bits and gaps.
Asynchronous is available anytime and anyplace and more opportunities for students or work related people to share multiple perspectives which means if you are tagged or included to a group chat like Facebook messenger you don’t have to reply or give a feedback immediately but of course the downside would be that it will be really difficult for you to keep track of the collaboration. It also often lacks a true social presence.

Synchronous transmission is more faster than Asynchronous because only a fewer bits have to be transmitted. The downside for Synchronous is that it is more complex and the hardware is more expensive. Synchronous communication features a real-time collaboration, it means that it will immediately respond to you. It is most useful for 1 on 1 communication and the presence for social is increased. For video or web conferencing for example it allows body language and tone of voice. It is basically a real-time collaboration with the person next to the

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