Networking And Telecommunication

Data Communication and Computer Networks

Overview

  • Data Communication: The exchange of data using computing and communication technologies between two or more points.

  • Telecommunication: Exchange of information over significant distances using electronic means.

Learning Goals

  • Understand different modes of data communication.

  • Identify types of transmission media and network components.

  • Explore various types of computer networks and their topologies.

Communication Protocol

  • Definition: Process of sharing views, ideas, and information between a sender and receiver through a medium.

  • Protocols establish rules for data transmission.

Modes of Data Communication

1. Simplex Mode

  • Data transmission in one direction only.

  • Examples: Television, radio.

2. Half Duplex Mode

  • Data can be transmitted in both directions, but not simultaneously.

  • Examples: Fax, Walkie-Talkie.

3. Full Duplex Mode

  • Data is transmitted in both directions at the same time.

  • Examples: Telephone, video chatting.

Transmission Media

Types of Transmission Media

  • Guided/Wired Media: Data is transmitted through physical cables.

    • Features: High speed, secure, used for shorter distances.

    • Types include Twisted Pair, Co-axial, and Fiber Optic Cables.

  • Unguided/Wireless Media: Data is transmitted through air using electromagnetic waves.

    • Types include Microwave, Radio Waves, Infrared, Bluetooth, and Satellite Communication.

Guided Media Types

Twisted Pair Cable

  • Reduced electromagnetic interference by twisting wires.

  • Types:

    • UTP (Unshielded Twisted Pair): Less expensive, high noise, higher signal reduction.

    • STP (Shielded Twisted Pair): More expensive, lower noise, lower signal reduction.

Coaxial Cable

  • Higher bandwidth than twisted pair.

  • Uses include cable TV.

    • Baseband: Transmits one signal at high speed.

    • Broadband: Transmits multiple signals using various frequencies.

Fiber Optic Cable

  • Transmits data as light pulses.

  • High speed over long distances, expensive.

Connectors for Transmission Media

  • Twisted Pair: RJ-45 and RJ-11

  • Coaxial: BNC (British Naval Connector)

  • Fiber Optics: ST, SC, FC, MT-RJ, LC connectors.

Computer Networks

  • Definition: A group of interconnected computers sharing data, resources, and services.

Types of Computer Networks

  • LAN (Local Area Network): Small geographical area.

  • MAN (Metropolitan Area Network): Larger than LAN, connects systems in a city.

  • WAN (Wide Area Network): Connects large geographical areas, such as the Internet.

Advantages of Computer Networks

  • Fast communication, centralized management, resource sharing, remote access, and easier backups.

Disadvantages of Computer Networks

  • Complexity in setup, cost, security vulnerabilities, and potential for virus spread.

Basic Elements of Computer Network

Hardware Components

  1. NIC (Network Interface Card): Connects computers to the network.

  2. Hub: Connects multiple devices in a star topology.

  3. Switch: Connects devices in a more efficient manner than a hub.

  4. Connectors: RJ-45, BNC, ST, etc.

  5. Bridge: Connects two networks with similar protocols.

  6. Router: Connects different networks with different protocols.

  7. Brouter: Functions as both a bridge and a router.

  8. Gateway: Connects dissimilar networks and converts protocols.

  9. Repeater: Regenerates weak signals for long-distance communication.

  10. Modem: Converts signals between analog and digital.

Software Components

  • NOS (Network Operating System): Manages network resources.

  • Examples of NOS: Windows NT, Windows Server, Linux, UNIX.

Network Architecture

  • Defines communication and interaction among computers in a network.

Types of Network Architecture

  1. Peer-to-Peer (P2P): Equal relationships; suitable for smaller networks.

  2. Client-Server: Servers provide resources and services; centralized control.

  3. Centralized Network: Host computer controls all processes; limited processing on workstations.

Network Topologies

Types of Topologies

  1. Bus Topology: All devices connected to a single cable.

  2. Ring Topology: Devices connected in a circular fashion.

  3. Star Topology: All devices connected to a central hub.

  4. Mesh Topology: Devices interconnected, providing various paths.

  5. Tree Topology: Combines bus and star topologies, structured like a tree.

Internet and Its Services

  • The Internet is a worldwide network of interconnected networks.

  • Services include the World Wide Web, e-mail, chatting, video conferencing, and online banking.