Telecommunications and Networks

Telecommunications and Networks Notes

Chapter Overview

  • Title: Introduction to Information Systems, Chapter 6: Telecommunications and Networks
  • Authors: O'Brien & Marakas
  • Publisher: McGraw-Hill Irwin, 2010
Contents at a Glance
  • The Networked Enterprise
    • Metcalfe's Law
    • Internet, Intranets & Extranets
  • Telecommunications Trends
    • Business value of network technologies
  • Network Alternatives
    • Types, architectures, protocols
      • TCP/IP
      • OSI
  • Transmission Media
    • Wired (twisted pair, coaxial, fiber optic)
    • Wireless (Wi-Fi, cellular, satellite)
  • Network Topologies
    • Star, ring, bus, and hybrid configurations
  • Bandwidth & Switching
    • Circuit, packet, and virtual circuit switching
  • Client/Server & Peer-to-Peer Networking Models
  • Real-World Case Studies
    • Starbucks Wi-Fi, Brain Saving Technologies, Metric & Multistandard

Learning Objectives

  1. Understand the concept of a network.
  2. Apply Metcalfe's law in understanding the value of a network.
  3. Identify major developments and trends in telecommunications and Internet technologies.
  4. Provide examples of the business value of Internet, intranet, and extranet applications.
  5. Identify telecommunications networks' basic components, functions, and types used in business.
  6. Explain functions of major components of telecommunications network hardware, software, media, and services.
  7. Explain the concept of client/server networking.
  8. Understand two forms of peer-to-peer networking.
  9. Explain the difference between digital and analog signals.
  10. Identify various transmission media and topologies used in telecommunications networks.
  11. Understand fundamentals of wireless network technologies.
  12. Explain concepts behind TCP/IP.
  13. Understand the seven layers of the OSI network model.

SECTION I: The Networked Enterprise

Networking the Enterprise
  • Network Definition: An interconnected or interrelated chain, group, or system. Examples include:
    • Chains of hotels
    • Road systems
    • Railroad networks
    • Organizational memberships
  • Computing and Communications Convergence: When computers are networked, the result is a significant enhancement of business capabilities, allowing for collaboration, operation management, and competitiveness.
  • Global Internet as a Platform: Creates a public, borderless cyberspace for interactions and commerce, revolutionizing society and organizational structures.
The Concept of a Network
  • Connections Calculation: Total possible connections in one-way communication is calculated as N(N−1)extorN2−NN(N-1) ext{ or } N^2 - N
    • Where N = number of nodes.
    • Example of connections:
      • N = 3 → Connections = 6
      • N = 10 → Connections = 90
      • N = 100 → Connections = 9,900
      • N = 1,000 → Connections = 999,000
Metcalfe's Law
  • Definition: The value of a network is proportional to the square of the number of users. If N = number of users: Valueext(Utility)=N2Value ext{ (Utility)} = N^2
    • Explains rapid value increase of networks like the Internet and social networks.
Telecommunications Trends
  • Industry Trends:
    • Movement from regulated monopolies to a competitive market.
    • The Internet as a major competitive member.
  • Technology Trends:
    • Surge in Internet, wireless, and broadband technologies replaces traditional telephony.
  • Applications Trends:
    • Growth of Internet-focused business models—e-commerce, electronic business, and collaboration tools.
Business Value of Telecommunications Networks
  • Strategic Capabilities:
    • Geographic Barriers: Efficient information flow across distances
    • Time Barriers: Instant information availability from remote locations
    • Cost Barriers: Reduced communication costs (mail, phone, meetings)
    • Structural Barriers: Connects partners across organizational boundaries.
The Internet Revolution
  • Internet Growth:
    • Originally a U.S. government research tool, now supports over a billion regular users.
  • Key Characteristics:
    • Open standards (e.g., TCP/IP), ease of access, multimedia capabilities, support for commerce without geographic limits.
The Role of Intranets
  • Definition: A private network using Internet technology for internal communications, secured through firewalls.
    • Enables employees to access, collaborate, and communicate internally.
The Role of Extranets
  • Definition: Network connecting select intranet resources with external business partners.
    • Facilitates orders, inventory checks, and document access for authorized external parties.

SECTION II: Telecommunications Network Alternatives

Telecommunications Alternatives
  • Components in a Telecommunications Network:
    • Terminals: Input/output devices for data transmission.
      • Examples: Computers, smartphones, etc.
    • Processors: Devices supporting data transmission such as modems or multiplexers.
    • Channels: Media over which data flows (wired/wireless).
    • Computers: Interconnected devices ranging from servers to desktop PCs.
    • Software: Operating systems and applications managing network functions.
Types of Telecommunications Networks
  • Local Area Networks (LAN):
    • Connects devices within a limited area (e.g., offices).
    • Speed: Typically 100 Mbps to 10 Gbps.
  • Wide Area Networks (WAN):
    • Covers larger regions (countries/globe) using common carriers or leased lines.
  • Metropolitan Area Networks (MAN):
    • Serve a city or suburb, usually operated by a single entity (e.g., city government).
  • Virtual Private Networks (VPN):
    • Uses public Internet with security features to create a private network.
Client/Server Networks
  • Architecture:
    • End-user PCs (clients) connected to powerful computers (servers).
    • Server Types: File servers, print servers, database servers, etc.
Peer-to-Peer (P2P) Networks
  • Types:
    1. Real P2P Networks: Small networks without a central server.
    2. Internet P2P: File sharing directly between computers without central control.
Digital and Analog Signals
  • Analog Signals:
    • Continuous waveform varying in frequency and amplitude.
    • Used in traditional telephone systems.
  • Digital Signals:
    • Discrete voltage pulses (1/0).
    • Used in modern computing networks.
Telecommunications Media
  • Wired Technologies:
    • Twisted-Pair Wire: Common, inexpensive, limited bandwidth (10-100 Mbps).
    • Coaxial Cable: Higher bandwidth, used in cable TV networks.
    • Fiber Optic Cable: Very high bandwidth (up to terabits/sec), long-distance transmission.
  • Wireless Technologies:
    • Terrestrial Microwave: High-speed radio signals line of sight; used for point-to-point links.
    • Communications Satellites: Provide services to remote areas.
    • Cellular Networks (3G/4G/LTE): Mobile communication covering geographic cells.
    • Wi-Fi (IEEE 802.11): Wireless local area networking standard.
    • Bluetooth: Short-range connectivity for peripherals.
    • WiMAX: Broadband wireless access for metropolitan areas.
Telecommunications Processors
  • Modem: Converts digital signals to/from analog for transmission.
  • Multiplexer: Combines multiple data signals over a single channel.
  • Router: Determines optimal paths for data packets.
  • Switch: Creates dedicated connections to minimize data collisions.
  • Hub: Simple connection point for devices sharing bandwidth.
  • Gateway: Connects different networks using various protocols.
  • Bridge: Connects similar LAN segments to reduce traffic congestion.
  • Front-End Processor: Manages communications for a host computer.
Network Topologies
  • Star Topology: Nodes connected to a central hub. Simple but failure of the hub impacts the whole network.
  • Ring Topology: Nodes connected in a closed loop; data travels in one direction.
  • Bus Topology: Nodes connected to a common backbone; failure disrupts communication.
  • Mesh Topology: Nodes interconnected to provide redundancy.
  • Hybrid Topology: Combination of two or more basic topologies.
Network Architectures and Protocols
  • Protocol: A definitive set of rules for communication control in networks.
  • TCP/IP (Transmission Control Protocol/Internet Protocol): The standard suite of Internet protocols organized into layers:
    • Application Layer: Protocols like HTTP, FTP, SMTP, DNS.
    • Transport Layer: TCP (reliable) and UDP (faster, not guaranteed delivery).
    • Internet Layer: IP handles addressing/routing.
    • Network Access Layer: Manages physical transmission of data based on networks.
  • OSI Model: Seven-layer framework for network protocols:
    • Layer 7: Application
    • Layer 6: Presentation
    • Layer 5: Session
    • Layer 4: Transport
    • Layer 3: Network
    • Layer 2: Data Link
    • Layer 1: Physical

Bandwidth Alternatives

  • Definition: The data transmission capacity measured in bps (bits per second). Categories include:
    • Narrowband: Up to 64 Kbps (Standard telephone)
    • Medium Band: 64 Kbps - 1.544 Mbps (ISDN, DSL)
    • Broadband: 1.544 Mbps - 100+ Mbps (Cable modem)
    • Ultra-Broadband: 1 Gbps and above (Fiber optic).
Switching Alternatives
  • Circuit Switching: A dedicated channel for the entire call; inefficient during silence periods.
  • Packet Switching: Data sent in packets which travel independently; efficient for bandwidth utilization.
  • Virtual Circuit Switching: Combines circuit-switched and packet-switched technologies (ATM).
Network Interoperability
  • Definition: Different computers/networks/functions working together; a significant challenge in networking.
  • Interoperability Technologies: Examples include gateways, bridges, routers, and VPNs.

Key Terms and Concepts

  • Analog Signal: Continuous wave signal; traditional telephone networks.
  • Modem: Converts digital and analog signals for transmission.
  • Bandwidth: Channel capacity in bits per second (bps).
  • Network Topology: Physical/logical arrangement of nodes.
  • Broadband: High-speed telecommunications.
  • OSI Model: Framework for network protocol design.
  • Client/Server Network: Architecture where clients are served by servers.
  • Packet Switching: Method of transmitting data in packets.
  • Coaxial Cable: Transmission medium with copper conductor.
  • Protocol: Rules for network communications.
  • Digital Signal: Binary pulse signal used in computers.
  • Router: Device managing data traffic on networks.
  • Extranet: Links a company’s intranet with external partners.
  • TCP/IP: The foundational protocol suite for the Internet.
  • Fiber Optic Cable: High-speed transmission medium using light.
  • Twisted-Pair Wire: Common network media with twisted wires.
  • Firewall: Monitors network traffic for security.
  • VPN: Secure network using public Internet infrastructure.
  • Intranet: Private network for internal communication.
  • WAN (Wide Area Network): Large geographic area network.
  • LAN (Local Area Network): Network for confined areas like offices.
  • Wi-Fi (IEEE 802.11): Wireless networking standard.
  • Metcalfe's Law: Utility of a network grows with the square of its users.

Chapter Summary

  • Network Revolution: Telecommunications and networks have empowered businesses by eliminating various barriers and creating opportunities for enhanced operations and competitiveness.
  • Internet Dynamics: The Internet serves as a vast resource for communication and commerce, with intranets and extranets extending its functionalities into corporate environments.
  • Diversity of Networks: Networks vary significantly in scope from LANs to WANs, employing dominant architectures and protocols to ensure efficient functionality.
  • Transmission Media: Different wired and wireless technologies offer varying degrees of effectiveness for communication.
  • Infrastructure Frameworks: TCP/IP and the OSI model outline the structure necessary for network interactions and interoperability, vital for successful contemporary networking.