CH 7: Telecommunications, the Internet, and Wireless Technology Notes

Telecommunications, the Internet, and Wireless Technology

Learning Objectives

  • Understand the principal components of telecommunications networks and key networking technologies.

  • Identify different types of networks.

  • Learn about principal technologies and standards for wireless networking and Internet access.

What is a Computer Network?

  • A computer network consists of two or more connected computers.

  • Major components of a simple network:

    • Client and server computers: Client requests resources/services while server provides them.

    • Network Interface Cards (NICs): Hardware that connects computers to a network.

    • Connection medium: The physical pathway (cables or wireless) that carries data.

    • Network Operating System (NOS): Manages hardware and software resources in a network.

    • Hubs, switches, routers: Devices that manage data traffic in networks.

Components of a Simple Computer Network

  • Server: Dedicated machine that runs the NOS.

  • Cabling: Wiring that connects network devices.

  • Switches: Connect multiple devices on a LAN and manage data flow.

  • Router: Connects different networks and directs data packets between them.

Networks in Larger Companies

  • Large organizations deploy multiple LANs connected to a corporate network.

  • Use of powerful servers for:

    • Hosting websites and corporate intranets/extranets.

    • Backend systems to manage data and applications.

  • Integration of mobile wireless LANs (Wi-Fi), videoconferencing, and telephony networks.

Corporate Network Infrastructure

  • Distinction between Wireless LAN (WLAN) for indoor wireless access and Mobile Wi-Fi networks for external connectivity.

Key Digital Networking Technologies

Client/Server Computing

  • Definition: Computing model where clients request and servers provide resources.

  • Benefits: Sets communication rules, provides addresses for client identification.

  • The Internet is the largest client/server system globally.

Packet Switching

  • Definition: Data transmission method that breaks messages into smaller packets.

  • Process:

    • Packets travel independently over different paths and are reassembled at the destination.

  • Advantage: More efficient use of network capacity compared to circuit-switched networks.

TCP/IP and Connectivity

  • TCP/IP: A set of protocols governing internet communications.

    • The world standard for internet connectivity.

  • Structure consists of four layers:

    1. Application Layer

    2. Transport Layer

    3. Internet Layer

    4. Network Interface Layer

Types of Networks

  • Digital vs. Analog Signals: Modems convert digital signals to analog and vice versa.

  • Types:

    • Local Area Networks (LANs): Up to 500 meters, typical for a building/office.

    • Campus Area Networks (CANs): Cover college campuses.

    • Metropolitan Area Networks (MANs): Cover cities.

    • Wide Area Networks (WANs): Span regional to global areas.

Modem Functions

  • Translates signals between digital data and analog forms for data transmission.

The Internet Basics

  • Internet Service Providers (ISPs): Offer internet connections (e.g., DSL, cable, fiber).

  • Each device has a unique IP address (Internet Protocol) for identification.

  • Domain Name System (DNS): Converts IP addresses into domain names for easier navigation.

    • Structured hierarchically with top-level and second-level domains.

Transmission Media

  • Types:

    • Twisted Pair Wire: Common for LAN (up to 100 Mbps).

    • Coaxial Cable: Less interference, used in TV and longer runs.

    • Fiber Optics: High-speed data transmission; more expensive and complex.

    • Wireless Transmission: Uses radio signals for long-distance communication.

Cellular Systems

  • CDMA and GSM: Competing standards for mobile communications.

    • 3G networks support basic tasks (email, browsing).

    • 4G networks support high-speed data (video streaming).

    • 5G networks provide gigabit capacities with wider rollouts.

Wireless Computer Networks

  • Bluetooth: Connects devices within 10 meters typically for personal networking.

  • Wi-Fi: Standard for wireless LAN; connects using access points.

    • Hotspots allow public wireless access but often have weak security.

  • WiMax: Wider coverage up to 31 miles but requires specialized antennas.

Internet Services

  • VoIP: Digital voice communication over the internet.

  • Unified Communications: Merges voice, data, and video.

  • VPN: Provides secure connections over the internet.

The Future

  • Transitioning to IPv6 for addressing larger networks (more than a quadrillion addresses).

  • Development of Internet2 for high-capacity networks and testing new technologies.

  • Predicted shifts include the Internet of Things (IoT), increased cloud computing, and seamless connectivity.