Data communication involves the transmission of electronic data between nodes through a communication medium. There are several fundamental principles and basic elements of a communication system. The principles include delivery of data to the correct destination, accuracy of the data, and timely delivery. The basic elements are the message, sender, medium, receiver, and protocols. Common wired media include twisted pair cable, coaxial cable, and fiber optic cable. Wireless media include Bluetooth, Wi-Fi, and cellular networks. Protocols like TCP/IP govern how devices communicate by handling delivery and addressing. Data can be transmitted in analog or digital form.

1. DATA COMMUNICATION
Abdul Rehman

2. OUTLINES
• Data communication
• Fundamental principles of communication system
• Basic elements of Communication System
• Data Transmission media
• Protocols
• Data transmission forms

3. DATA COMMUNICATION
• Data communication is the flow of electronic data among two nodes(computers or
other devices) through communication media
• in order to manage communication, the nodes must be part of communication
system linked with each other via some media like cables or Wireless.
• In data communication/networking computers or devices which are connected to
network are termed as nodes.

5. FUNDAMENTAL PRINCIPLES OF
COMMUNICATION SYSTEM
• Delivery
• The System must carry data with correct end or destination
• The data must be received by correct recipient (device/user)
• Accuracy
• The system must deliver the data with same as it was sent
• The altered or incomplete data is useless
• Timeliness
• The system must deliver data in time
• Late delivery may not be useful
• Therefor time delivery is mandatory

6. BASIC ELEMENTS OF COMMUNICATION SYSTEM
• Message
• Message is the information that is communicated over the communication system. It includes
text, audio video images.
• Sender
• The node that is used for transferring data is called source or sender.
• In recent digital system the source is mostly computer or a mobile device
• Medium
• Medium is the pathway through which data is sent fro one point to another.
• If the receiver and sender are within the building, a wire (medium) can connect them.
• If they are at different locations they maybe connected through telephone lines, fiber optics
e.t.c.

7. BASIC ELEMENTS OF COMMUNICATION SYSTEM
CONT…
• Receiver
• The node that receives data is called receiver. The receiver can be computer, mobile device
printer
• Protocols
• A protocol Is set of rules which govern the data transmission between sender or receiver
• Without protocol the data is useless for receiver, as a person understanding only Urdu cannot
understand English messages
• Therefor messages transferred through medium to received are sent through protocol so that
receiver can understand the message.
• Most used communication protocol is TCP/IP (Transmission control Protocol/Internet Protocol)

8. DATA TRANSMISSION MEDIA
• To connect the devices in a network, either wired media (physical cables) or wireless
media (typically radio signals) can be used.
• The most common wired and wireless networking media are discussed next.

9. WIRED NETWORKING MEDIA
• The most common types of wired networking media:
• Twisted Pair Cable
• Co-Axial Cable
• Fiber optic cable

10. TWISTED PAIR CABLE
• Twisted pair is couple of copper wires, twisted together and enfolded a
plastic coating.
• Each pair consists of two wires used for positive data signal and negative
data signal
• Further divided into two categories UTP and STP
• Shielded twisted pair cable
• Its enclosed with foil cover and copper shielding
• STP Cable uses shields to reduce outside interference
• Unshielded twisted pair cable
• Is not enclosed in any cover
• Very flexable and easy to use

12. WIRELESS NETWORKING MEDIA
• Short Range
• Bluetooth
• Zigbee
• Medium Range
• Wifi
• Large Range
• WiMax
• 2G,3G,4G

13. PROTOCOLS USED IN DATA
COMMUNICATION
• A protocol is a set of rules to be followed in a specific situation
• there are communications protocols that determine how devices on a network
communicate.
• The most widely used communications protocol today is TCP/IP. TCP/IP is the
protocol used for transferring data over the Internet and actually consists of two
protocols:
• Transmission Control Protocol (TCP), which is responsible for the delivery of data
• and Internet Protocol (IP), which provides addresses and routing information.

14. DATA REPRESENTATION FORMS
• Analog Transmission
• Analog is transmission of data in continuous wave form
• the human voice is example of analog data when someone talks an analog wave is created
in the air medium.
• Analog Signal

15. DATA REPRESENTATION FORMS CONT..
• Digital Transmission
• Digital is the transmission of data using on and off stages 1’s ad 0’s
• The combination of these codes forms the binary code
• The binary cords forms the data
• The data stored in computer memory is the form of digital data
• It can be converted into digital signal

16. THE END