Communication Systems

Communication Systems

In case of sending and receiving messages or data from one place to other place, we have many elements working together. All these elements put together to work efficiently is known as system. The communication system has the sole purpose of passing data or information in the most effective manner.

Communication system is the combination of the hardware, software and data transfer links that make up a communication facility of transferring data in a cost effective manner.

A communication system can either be analog or digital or a combination of the two. That is, the information can be transmitted in either analog or digital form with in the communication network. E.g. computer generated data are to be sent over analog telephone lines, the digital signals must be converted to analog form. The technique by which a digital signal is converted to its analog form is known as modulation. The reserve process that is conversion to its analog signal to its digital form at the destination device called demodulation. The process of modulation and demodulation that is the conversion of digital data to analog from and vice versa is carried out by a special device called modem (modulation/demodulation).

The analog form of message is sent via telephone line and then it reaches the destination where they are again transformed into digital pulses by the other modem connected with the receiver PC. Thus the message or data is transmitted and received by the two PC’s.

As the analog signal passes through the telephone lines, its strength starts decreasing with the distance, so amplifiers are used to boost the strength of the signal. These amplifiers add noise to the signal which sometimes causes disruption of the message. But good quality of the modem at receiving end as well as at the transmitting end is able to cut down the effect of the noise.

Data Communication & It's Components

Data Communication

Data Communication means sharing the information. This sharing can be local or remote or with in a building. Local communication usually occurs face to face, while remote communication take place over distance.

This term telecommunication includes telephony, television mean communication at a distance. The world tele is a Greek word which means “far”. The word data refers to the facts. In the context of computer information system, data are represented by binary information unit produced in the form of 0s (zero) and 1s (one).

Data Communication is the exchange of data between the two devices via some of transmission medium. Data communication devices must be the part of the communication system made up of a combination of Hardware and Software. The effective data communication has three fundamental characteristics.

1. Delivery. System must deliver the data to the correct destination.
2. Accuracy. System must deliver accurate data.
3. Timeliness. System must deliver the data in a timely manner.

Components of Data Communication

There are five major components of data communication system: -

1. Message. The information which is to be communicated.
2. Sender. Sending data communication device are the devices that sends data message. It can be computer, workstation, telephone, radio, camera and so on.
3. Receiver. Receiver is the device that receives the message. It can be a computer, workstation, telephone, TV and so on.
4. Medium. It is a physical path by which the message travels from sender to receiver.
5. Protocol. It is the set of rules that governs the data communication. It is agreement between the communication devices. Without a protocol, two devices may be connected but they are not communicating (With each other). Just as a person speaking Tamil cannot understand the language of the person who speaks only Punjabi.