Data Transmission Basics

Data Transmission

• Types of Personal Data
  • Volunteered Data: Shared by individuals, like social media profiles. Includes video files, pictures, text and audio files.
  • Observed Data: Captured by recording actions, like location data from cell phones.
  • Inferred Data: Based on analysis of volunteered or observed data, like credit scores.

The Bit

• Binary Digits: Computers use binary digits (bits), which have one of two values: 0 or 1.
• Smallest Piece of Data: A bit represents the smallest piece of data.
• Byte: A group of eight bits is called a byte.
• ASCII: The American Standard Code for Information Interchange (ASCII) uses eight bits to represent characters.
  • Capital Letter A: 01000001
  • Number 9: 00111001
  • Special Character #: 00100011

Common Methods of Data Transmission

• Media: Physical medium that signals are transmitted on, like copper wire, fiber-optic cable, or electromagnetic waves.
• Signals: Electrical or optical patterns transmitted between devices.
• Electrical Signals: Data is represented as electrical pulses on copper wire.

Coaxial and Fiber-Optic Cabling

• Coaxial Cable: Carries electrical signals with improved shielding compared to UTP.
  • Used for cable TV, satellite communications, and internet service.
• Fiber-Optic Cables: Transmit data using pulses of light. Made of glass or plastic, immune to interference.
  • Parts:
    • Jacket: Protects against abrasion, moisture, and contaminants.
    • Strengthening Material: Prevents stretching.
    • Buffer: Shields core and cladding from damage.
    • Cladding: Acts like a mirror.
    • Core: Light transmission element at the center.

Twisted-Pair Operation

• UTP Cable Color Coding: Determined by the type of standard used.
• Communication Elements:
  • Source: Sends the message (people or devices).
  • Destination: Receives the message.
  • Transmission Medium: Provides the path for the message.

The Rules

• Communication Protocols: Rules or agreements for communication.
  • Message Format: Structure of messages depends on the message type and channel.
  • Message Size: Rules govern the size of pieces transmitted across the network.
  • Timing: Affects transmission speed and data volume.
• Protocols for Data Transmission:
  • TCP (Transmission Control Protocol): Reliable delivery and flow control.
  • IP (Internet Protocol): Manages delivery of messages between sender and receiver.
  • Ethernet: Manages message delivery between network interface cards (NICs) on a local area network (LAN).

Network Communication Models

• Layered Models: Depict protocol operations within each layer.
  • Benefits:
    • Helps with protocol design.
    • Fosters competition between vendors.
    • Enables technology changes in one level without affecting others.
    • Provides a common language.
• TCP/IP Model: Four layers:
  • Application: Represents data to the user, encoding, and dialog control.
  • Transport: Supports communication between devices across networks.
  • Internet: Determines the best path through the network.
  • Network Access: Controls hardware devices and media.
• OSI Reference Model: Seven layers:
  • Application: Process-to-process communication protocols.
  • Presentation: Data representation for transfer.
  • Session: Organizes dialogue and manages data exchange.

Ethernet

• Ethernet Standards: Assigned by the 802.3 committee. Each version has a standard notation: 802.3 100BASE-T.
  • 100: Speed in Mbps.
  • BASE: Baseband transmission.
  • T: Type of cable (twisted-pair).
• Ethernet MAC Address: A physical address that identifies each host on the network.
  • Assigned During Manufacturing: Every Ethernet network interface card (NIC) receives a unique MAC address.
• Lab - Determine MAC Address:
  • Command: ipconfig /all on a Windows computer.
  • Analyze MAC Address: Determine the manufacturer.