Lecture 1: Data Communication System and Networking

Overview

• Introduction to data communication systems and networking.
• Understanding data transmission between devices.

Basic Elements of Data Transmission System

• Source: Device that stores data (e.g., mobile phones, desktops).
• Sender/Transmitter: Device that sends data (e.g., routers, modems).
• Medium: Connection between sender and receiver (e.g., optical fiber, wireless).
• Receiver: Similar to sender, receives data (e.g., routers, modems).
• Destination: Similar to source, receives final data (e.g., mobile phones, desktops).

Importance

• These five elements are core components of data communication and networking.

Bandwidth

• Definition: Data transmission speed/rate.
• BPS (Bits Per Second): Measures how much data is transferred per second.
• Examples:
  • 1 Mbps: Transfers 1 MB of data per second.
  • 12 Kbps: Transfers 12 kilobits of data per second.
  • 10 Gbps: Transfers 10 GB of data per second.

Difference Between Mbps and MBps

• Mbps (Megabits per second): Smaller 'b' indicates bits.
• MBps (Megabytes per second): Capital 'B' indicates bytes.

Classification of Bandwidth

• Narrow Band: Very slow speed (45-300 BPS).
• Voice Band: Medium speed (9.6 Kbps).
• Broadband: High speed (1 Mbps to 1 Gbps).

Data Transmission Methods

• Parallel Method:
  • Uses multiple lines for each bit.
  • Faster but expensive due to the need for multiple lines.
• Serial Method:
  • Uses a single line for all bits.
  • Slower but more cost-effective.

Differences Between Serial and Parallel Method

• Parallel: Faster, uses multiple lines.
• Serial: Slower, uses single line.

Memory in Data Transmission

• Used to store data during transmission.
• Parallel Method: Requires storage to send data.
• Serial Method: No storage needed as data is sent one by one.

Types of Serial Method

• Asynchronous
• Synchronous
• Isochronous
• To be discussed in detail in the next lecture.

Summary

• Core elements of data transmission: source, sender, medium, receiver, destination.
• Bandwidth and its types: narrow band, voice band, broadband.
• Data transmission methods: parallel and serial.
• Next lecture will cover types of serial methods based on synchronization.

Do you have any questions? The lecture will continue with more details on serial methods and synchronization in the next class. Till then, Allah Hafez.