Main Elements of The Data Communications

• The source : Generate data to be transmitted

          Ex : Phone and Pc

• Transmitter : Transform the data into signals that can be emitted

          Ex : Modem to change the digital signal to analog

• Transmission system : Bring the data transmision path connecting the source and purpose
• Receiver : Change the receiver signal into data

         Ex : modems convert analog signals into digital

• Distination : Data retrieval

 Transform The Data Into Signal

In data transmission, data there are 4 scenarions that could occur as follows :

• Sending digital data using digital signal
• Sending digital data using analog signal
• Sending analog data using digital signal
• Sending analog data using analog signal

Digital Encoding, Digital to digital conversion

    When the data to be sent in digital form (in the form 0 and 1), and transmission media capable of handling digital signals (which has a wide bandwidth) then the physical layer capable of to encode digital data into digital signals for transmission.

     Almost all of the LAN (Local Area Network) uses digital endoge-to-digital because the data is stored in the computer and the digital data cable that connects computers are capable of carrying digital singnals.