Transmission Media

☞ A physical path that is used for sending data or signals across the network.

☞ It is also termed as Communication Media.

☞ These are divided into two categories : 

1. Guided Media or Wired Media
2. Unguided Media or Wireless Media

Guided Media or Wired Media

☞ Wired media refers to physical transmission channels that use cables or wires to transmit data signals between devices.

☞ Following are the some guided media :

1. Twisted Pair Cable
2. Coaxial Cable
3. Optical Fibre Cable

Twisted Pair Cable

☞ A type of electrical cable consisting of pairs of insulated copper wires twisted together, designed to carry electrical signals.

☞ Commonly used in telephone lines, local area networks (LANs), and DSL internet connections.

☞ Advantages :

  • Cost-effective and easy to install.
  • Flexible and widely available.

☞ Disadvantages :

  • Susceptible to electromagnetic interference (EMI), which can degrade signal quality.
  • Limited bandwidth and range compared to other cables.

Coaxial Cable

☞ A cable made up of a central conductor, an insulating layer, a metal shield, and an outer insulating layer, used to transmit data signals.

☞ Commonly used in cable television, broadband internet, and telephone systems.

☞ Advantages :

  • Higher bandwidth and less interference compared to twisted pair cables.
  • Better shielding reduces susceptibility to external noise.

☞ Disadvantages :

  • Heavier and bulkier than twisted pair cables.
  • More expensive, especially for long distances.

Fiber-Optic Cable

☞ A cable that transmits data as light pulses through thin strands of glass or plastic fibers.

☞ Commonly used in high-speed internet connections, long-distance telecommunications, and high-performance networking.

☞ Advantages :

  • Extremely high data transfer speeds and bandwidth.
  • Immune to electromagnetic interference and signal degradation.

☞ Disadvantages :

  • Expensive to install and maintain.
  • Fragile and requires specialized handling during installation.

Unguided Media or Wireless Media

☞ Wireless media refers to transmission channels that use electromagnetic waves (such as radio, microwave, or infrared waves) to send data without physical cables.

☞ Following are the some guided media :

1. Radio Waves
2. Microwaves
3. Infrared Waves

Radio Waves

☞ A type of electromagnetic wave that is used for transmitting data wirelessly across long distances.

☞ Commonly used in broadcasting (radio and TV), mobile phone networks, and satellite communications.

☞ Advantages :

  • Supports long-range communication and mobility.
  • Widely available and commonly used for wireless communication.

☞ Disadvantages :

  • Prone to interference from other devices and weather conditions.
  • Limited bandwidth, resulting in lower data transfer rates.

Microwaves

☞ A form of electromagnetic radiation with frequencies higher than radio waves, typically used for point-to-point communication.

☞ Commonly used in satellite communications, microwave towers, and wireless internet services.

☞ Advantages :

  • High data transfer rates and ability to transmit large amounts of data.
  • Suitable for long-distance communication.

☞ Disadvantages :

  • Requires a direct line of sight between transmitting and receiving stations.
  • Can be disrupted by weather conditions like rain or storms.

Infrared Waves

☞ Electromagnetic waves with frequencies lower than visible light, often used for short-range communication.

☞ Commonly used in remote controls, wireless communication between devices, and short-range data transfer (e.g., Bluetooth).

☞ Advantages :

  • Secure, as it operates over a limited range and requires line of sight.
  • Low power consumption and inexpensive.

☞ Disadvantages :

  • Short range, typically limited to a few meters.
  • Requires direct line of sight, making it less flexible than other wireless media.