Transmission Media and its Types in Computer Networks

The term "transmission medium" refers to any medium that is utilized by computers in order to send data to networks.

Transmission media and communication channels both refer to the cables and other media that are used to connect nodes in a network. The communication channels are the cables that connect two or more individual workstations to one another.

Within the realm of transmission media, there are fundamentally two distinct types of medium, both of which are categorized as follows:

  • Copper medium
    • Coaxial cable
      • Thinnet cable
      • Thicknet cable
    • twisted pair cable
      • Shielded twisted pair cable, also called UTP cable
      • Unshielded twisted pair cable, also called HTP cable
  • Fiber optic
    • Single mode
    • Multi mode

This article discusses "coaxial cable" and "fibre optic," whereas "twisted pair cable" is discussed in its own separate article, which is located next to this article.

Coaxial Cable

The coaxial cable consists of a solid wire core that is surrounded by one or more foil or wire shields, each separated by some kind of plastic insulator.

The signal travels through the inner core of coaxial cable, while the ground travels through the shield. It has excellent electrical properties. It is appropriate for high-speed communication. It is less widely used than twisted-pair cable. It is commonly used to transmit television signals.

Coaxial cable, in the form of CATV cable, provides a low-cost means of transporting multi-channel television signals throughout metropolitan areas. Large corporations also use it in the construction of security systems.

Coaxial cable has better data transmission characteristics than twisted pair cable. As a result, the coaxial cable can be used as the foundation for a shared cable network, with a portion of the bandwidth dedicated to data traffic.

Types of Coaxial Cable

There are basically two kinds of coaxial cable listed here:

Let's take a closer look at the two types of coaxial cable.

Thinnet Cable

The first cable used in network cabling was thinnet cable. Between 1995 and 1996, this cable was in use. Thinet cable was only used in bus topologies.

IEEE 10Base-2 is another name for thinnet cable. IEEE is an organization that determines the standards for all cables. In this case, 10 denotes a data transmission rate of 10 Mbps, and 2 denotes the maximum segment length. The precise distance is 185 metres.

Two factors must be considered when purchasing a cable: the data transmission rate (how many mbps or gbps the cable has) and the segment length (how many maximum bytes the cable can transfer without being cut).

To transfer data, the thin cable employs a baseband signal. Baseband has a single frequency and broadband has multiple single frequencies.

A thinnet cable connector is known as a BNC (barrel net connector) T type connector.

Thicknet cable

The second type of coaxial cable is thicknet cable. IEEE 10base-5 is another name for thicknet cable.

The data transmission rate is 10 mbps, the baseband signal is 500 metres, and the segment length is 500 metres. The segment length is used in LAN.

An AUI connector is used in thicknet cable (attachment unit interface).

Advantages of Coaxial Cable

The use of coaxial cable has a number of advantages, some of which are listed below:

  • The data transmission characteristics of coaxial cables, in comparison to those of twisted pair cables, are superior. This much has been established.
  • The coaxial cables have the potential to serve as the backbone of a cable network that is shared by multiple users.
  • Broadband transmission can be accomplished through the use of the coaxial cables.
  • provides higher bandwidths, reaching up to 400 Mbps in some cases.

Disadvantages of Coaxial Cable

The use of coaxial cable has a number of drawbacks, some of which are as follows:

  • The cost of the coaxial cables is significantly higher than that of the twisted-pair cables.
  • Coaxial cables cannot be used with twisted pair cables because of their incompatibility.

Optical Fibers

Optical fibres are made up of very thin strands of glass or other materials that behave similarly to glass and are constructed in such a way that they are able to transmit light from a light source at one end of the fibre to a detector at the other end of the fibre.

LEDs, which is an abbreviation for "light-emitting diodes," or LDs are the types of light sources that are utilized (which stands for "laser diodes").

Using techniques that involve frequency modulation, the data that is intended to be transmitted is first modulated onto the light beam. After that, the signals can be received at the receiving end, where they can be picked up and demodulated.

The bandwidth of the medium has the capability of reaching very high levels. This can be anywhere from 20 Mbps to 150 Mbps for light-emitting diodes (LEDs), while laser diodes have the potential to achieve much higher transfer rates (LDs).

Internet service providers typically connect their networks with fibre optic cable.

Following is a list of the three components that make up the fibre optic cable:

  • the core: the glass or plastic through which the light travels
  • The cladding is a covering for the core that reflects light back to the core.
  • protective coating: protects the fibre cable from hostile environments

Types of Optical Fiber Cable

In the list below, there are two types of fibre optic cable described:

  • Single node: Supports segment lengths of up to 2 km and bandwidths of up to 100 Mbps.
  • Multinode: Up to 100 km segment length and 2 GB bandwidth are supported.

The Benefits of Optical Fiber Cable

The following are some of the primary benefits of using optical fibre cables:

  • Because the information is traveling on a modulated light beam, fibre optics is immune to electrical and magnetic interference, i.e., noise in any form.
  • Fiber optics are ideal for use in harsh industrial environments.
  • Fiber optics ensures secure transmission while also having a very high transmission capacity.
  • Fiber optic cables can be used for broadband transmission where multiple channels, i.e., frequency bands, are handled in parallel and where data transmission channels can be mixed with telescope, graphics, TV, and sound channels.

The Drawbacks of Optical Fiber Cable

The following are some of the major drawbacks of using optical fibre cables:

  • Installation is difficult because fibre optic cables are quite fragile and may require special care to make them robust enough for an office environment.
  • Connecting two fibres or a light source to a fibre is a difficult process.
  • Because of their noise immunity, optical fibres are nearly impossible to tap. In order to receive the signal, the fibre must be severed and a detector inserted.
  • Out of phase light can reach the receiver.
  • Connection losses are a common issue with optical fibre cables.
  • Soldering fibre optic cables is more difficult.
  • Among all the cables, optical fibre cables are the most expensive.

Comparison of Guided Media

Now it's time to compare the cost, ease of use, and performance of each of the media we've learned so far. As a result, the following table compares these factors for various media:

Type Type Sub Type Maximum Segment Length Bandwidth Supported Installation Cost Interference
Twisted Pair Cable UTP
100 meters
100 meters
100 Mbps
Coaxial Cable Thinnet
185 meters
500 meters
10 Mbps
10 Mbps
Fibre Optic Cable Multinode
2 kms
100 kms
100 Mbps
2 Gbps
very hard
very hard

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