define types of transmission media?
define any 5?
Answers
In network communications, a transmission medium is a physical connection or an interface between the transmitter and the receiver. There are two major categories of transmission media, namely guided and wireless (or unguided). Let us take a walk through the types of transmission media and connectors in detail in this lesson.
Let's first take a closer look at the different types of guided transmission media one at a time.
1. Twisted Pair Cable
Twisted pair cables have been around for a long time. They were mainly invented for voice transmissions. Twisted pair is a widely used medium in networking because it's lighter, cheaper, more flexible, easy to install, and provides greater speeds than coaxial cables. There are two types of twisted pair cables: the unshielded twisted pair (UTP) and the shielded twisted pair (STP). Let's take a closer look at each of them.
The unshielded twisted pair cable has 4 pairs of copper wires that are present inside a plastic sheath. These wires are twisted to protect them from interference. The only protection available for a UTP cable is a plastic sheath that is thin in size.
The shielded twisted pair cable is widely used in high-speed networks. The major difference between UTP and shielded twisted pair is that STP makes use of a metallic shield to wrap the wires. This metallic shield prevents interference to a better extent than UTP. These STP cables come with numbering; the higher the numbering, the better the interference prevention. As an example: most computer networks must go with CAT 3 or CAT 5, and nothing less than this.
2. Coaxial Cables
The coaxial cables have a central copper conductor, surrounded by an insulating layer, a conducting shield, and the outermost plastic sheath. Thus, there are three insulation layers for the inner copper cable. There are two basic modes of data transmission in coaxial cables: baseband mode that has dedicated bandwidth, and broadband mode that has distributed cable bandwidth.
Cable TV and analog televisions mainly use coaxial cables. Coaxial cables have better resistance to cross talk than twisted pair cables. The coaxial cables are used for long distance communication. The most widely used types of coaxial cables are RG-59 and RG-6 (RG stands for 'radio guide'). RG-59 has lesser shielding and is suitable for short cable lengths and cable TV connections
There are many advantages to coaxial cables, including the following:
- High bandwidth
- Easy and cheap installation
- Better immunity from noise
- Better scaling
However, there are also a number of disadvantages to coaxial cables, which include the following:
- They're more prone to lightning strikes.
- They cover less distance than fiber optic cables.
- They carry less bandwidth than both fiber optic and twisted pair cables.
3. Optical Fibers
Optical fibers use light waves for transmission. Crosstalk, EMI, and attenuation aren't issues with optical fibers. These cables are well-suited for voice, data, and video transmissions. Optical fibers are the most secure of all the cable media. Installation and maintenance are difficult and costly. Fiber optic cables have greater transmission speed, high bandwidth, and the signal can travel longer distances when compared to coaxial and twisted pair cables. Though the cost of optical fiber cable is less compared to co-axial and twisted pair cables, the additional optical components needed for installation make fiber optic the costliest of all the cables.
The advantages of optical fibers include the following:
- There is zero interference and covers major cities and countries.
- They have high speed and high bandwidth.
- They're highly secure.
There also are a number of disadvantages, including the following:
- Installation and maintenance are difficult.
- Cabling is costly.
- Retrofitting an existing network is difficult, since optical fibers are incompatible with many types of electronic networking equipment.
4. Wireless or Unguided Transmission Media
The features of wireless/unguided transmission media are that the signal gets broadcast without any guided medium through the air and is less secure. There are three types of wireless transmission media:
- Radio wave
- Infrared
- Microwave
The advantages of unguided transmission media include the following:
- They are useful in wireless remote accessing methods.
- Networks can be expanded without disturbing the current users.
The disadvantages include:
- Potential security issues.
- They have limited speed compared to guided transmission media.
5.microscopic line
Microstrip is a type of electrical transmission line which can be fabricated with any technology where a conductor is separated from a ground plane by a dielectric layer known as the substrate. Microstrip Lines are used to convey microwave-frequency signals.
Twisted-pair cable is a type of cabling that is used for telephone communications and most modern Ethernet networks. A pair of wires forms a circuit that can transmit data. The pairs are twisted to provide protection against crosstalk, the noise generated by adjacent pairs.
Coaxial cable, or coax is a type of electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric; many coaxial cables also have a protective outer sheath or jacket.
A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an electrical cable, but containing one or more optical fibers that are used to carry light.
Strip line is a transverse electromagnetic transmission line medium invented by Robert M. Barrett of the Air Force Cambridge Research Centre in the 1950s. Strip line is the earliest form of planar transmission line.
Microstrip is a type of electrical transmission line which can be fabricated with any technology where a conductor is separated from a ground plane by a dielectric layer known as the substrate. Microstrip Lines are used to convey microwave-frequency signals.