The document discusses computer communication and networks. It covers topics like data communication, the brief history of communication from the telegraph to modern networks, and data communication systems. The key points are: - Data communication is defined as the exchange of information between entities using a transmission medium. - The core components of a basic data communication system are a message, sender, receiver, transmission medium, and communication protocol. - More complex systems connect multiple devices over different mediums like twisted wire, microwave, coaxial cable, and fiber optic cable that provide varying speeds and costs.

1. COMPUTER COMMUNICATION
AND NETWORKS

2. BOOKS
“Data Communications and Networking”
latest Edition by Behrouz A. Forouzan
“Data and Computer Communication” 8th
Edition by William Stallings

3. Today ‘s Topics
 Data Communication
 Brief History of Communication
 Data Communication System

4. DATA COMMUNICATION
“Data Communication is the
exchange of Information from
one entity to the other using a
Transmission Medium”

5. History of Data Communication
Telegraph 1837 Samuel Morse
Telephone 1876 Alexander Graham
Bell
By 1950’s
1970’S
Today

6. DATA COMMUNICATION
“Data Communication is the
exchange of Information from
one entity to the other using a
Transmission Medium”

7. Data Communication
“Data Communication is the
exchange of data (in the form of
0’s and 1’s) between two devices
(computers) via some form of the
transmission medium.”

8. LOCAL and REMOTE
Communication
LOCAL
–Communicating devices are
present in the same building or
a similarly restricted
geographical area

9. LOCAL and REMOTE
Communication
REMOTE
–Communicating devices are
present farther apart
VAGUE DEFINITIONS
We will clarify

10. Data Communication System
For Data Communication to occur,
communicating devices must be a part of
a system made up of some specific kind of
hardware and software. This system is
known as
“DATA COMMUNICATION SYSTEM”

11. Effectiveness of Data Comm.
System
Effectiveness depends upon three
fundamental characteristics:
 Delivery
 Accuracy
 Timeliness

12. Components of a Simple Data
Communication System

13. Components of a Data
Communication System
 A Data communication system
is made up of 5 components:
 Message
 Sender
 Receiver
 Medium
 Protocol

14. Message Types

15. Transmission Media
Medium Speed Cost
Twisted Wire 300bps-10Mbps Low
Microwave 256Kbps-100Mbps Low
Coaxial Cable 56Kbps-200Mbps Low
Fiber Optic
Cable
500Kbps-10Gbps High

16. A Complex Data Comm. System

17. EXAMPLE – Electronic Mail

18. An Actual Digital Data
Communication System