Wireless Transmission Media Quiz

Wireless Transmission Media

• Radio Waves

  • Transmission: Omnidirectional, send in all directions
  • Applications: Multicasting data, covering large areas
  • Penetration: Can penetrate obstacles like buildings and walls
  • Frequency range: 3 kHz to 1 GHz
  • Issues: Potential interference from other signals with the same bandwidth or frequency

• Infrared

  • Transmission: Short distance communication only, cannot penetrate barriers
  • Frequency range: 300 GHz to 400 THz
  • Advantages: High data rates due to larger bandwidth, less interference
  • Security: More secure than radio waves

• Microwaves

  • Transmission: Line-of-sight, transmitter and receiver antenna must be aligned
  • Suitable for: Shorter distances
  • Frequency range: 1 to 400 GHz
  • Bandwidth: 1 to 10 Mbps
  • Distance: Distance covered is proportional to the height of the antenna
  • Types: Terrestrial and satellite microwave transmission

Guided Transmission Media

• Unshielded Twisted Pair (UTP)

  • Advantages: Less expensive, easy to install, high-speed
  • Disadvantages: Attenuation limits distance, susceptible to external interference

• Shielded Twisted Pair (STP)

  • Advantages: Reduced crosstalk, faster than UTP
  • Disadvantages: Bulky, expensive, difficult to install

• Optical Fiber Cable

  • Advantages: Increased bandwidth, immunity to interference
  • Disadvantages: High cost, fragile

• Coaxial Cable

  • Advantages: High bandwidth, noise immunity
  • Disadvantages: Complete disruption due to single cable failure

Media Access Control (MAC)

• MAC Sublayer: Controls hardware for interaction with wired, optical, or wireless transmission medium
• Part of: Data Link Layer (along with Logical Link Control (LLC))
• LLC: Provides flow control and multiplexing for the logical link (e.g., EtherType, VLAN tag)
• MAC: Provides flow control and multiplexing for the transmission medium

Code Division Multiple Access (CDMA)

• Protocol: Used in 2G and 3G wireless communication
• Multiplexing: Allows multiple signals on a single transmission channel, optimizing bandwidth
• Technology: Utilizes spread spectrum technology to transmit signals
• Frequency Bands: Used in 800 MHz and 1.9 GHz bands for cellular phone systems

Twisted Pair Cable

• Construction: Two insulated conductors twisted together
• Purpose: Improves electromagnetic compatibility, reduces interference
• Types
  • Unshielded Twisted Pair (UTP)
    • No physical shield
    • Affordable, easy to set up
    • High-speed link
  • Shielded Twisted Pair (STP)
    • Foil shield to block external interference
    • Higher data transmission rate
    • Used in fast-data-rate Ethernet and telephony

Optical Fiber Cable

• Construction: Thin strands of glass that guide light
• Applications: Long-distance communication
• Advantages: High data capacity, long distances without repeaters, low maintenance costs
• Types: Unidirectional and bidirectional

Coaxial Cable

• Construction: Two parallel conductors insulated separately with an insulation layer
• Signal Transmission: Baseband and broadband modes
• Advantages: High-frequency signal transmission without significant loss
• Importance: Controlled dimensions and spacing for efficient transmission

Unguided Transmission Media

• Also known as: Unbounded, wireless media
• Transmission: Electromagnetic signals without a physical medium
• Medium: Air
• No physical connection: Between transmitter and receiver