A communication channel that conveys data from the sender to the recipient is known as transmission media. Electromagnetic signals are used to transfer data.
The transmission media's primary role is to transport data in the form of bits over a local area network (LAN) (Local Area Network).
In data communication, it is a physical link between the transmitter and the receiver.
What is Transmission Media?
Transmission media, or communication channels or communication lines, refer to the physical media through which data is transmitted from one device to another. They are used to establish communication between two or more devices. It allows them to exchange information and data.
The choice of transmission media depends on various factors, like the distance over which data needs to be transmitted, the data rate or the required bandwidth, the cost of the media, and the reliability of the medium.
Types of Transmission Media
Guided Transmission Media
Unguided Transmission Media
In this Blog we will discuss only guided Transmission Media:
What is Guided Media?
Guided Transmission Media, also known as Wired or Bounded transmission media, is the physical medium through which the signals are transmitted. The transmitted signals are directed and confined in a narrow pathway using physical links.
It provides us with features like higher speeds, and better security and is used preferably for comparatively shorter distances. A signal traveling along any such media is directed and contained by the physical limits of the medium.
Guided transmission media refers to the physical channels through which signals are directed along a defined path. This includes cables and optical fibers that guide electromagnetic or light signals from one point to another. These media are essential for wired communication networks, providing the infrastructure for internet, telephony, and cable television services. They offer reliable and high-quality signal transmission with varying capacities and speeds, depending on the material (e.g., copper, fiber optic) and technology used, making them fundamental for both local and wide area networks.
Types of Guided Transmission Media
There are three types of Guided Transmission Media:
Twisted Pair cable
Coaxial cable
Fibre Optic Cable
We are going to discuss each of these types in detail in the following sections.
Twisted Pair Cable
Twisted-Pair Cables are cables consisting of two insulated conductor wires (typically copper) wound and twisted together arranged in a regular spiral pattern. One wire carries the signal to the receiver, and the other is used as a ground reference. The receivers use the difference between the two to interpret signals. Generally, several such pairs are bundled together in a protective sheath. Twisting is done to make sure the noise will equally affect the wire from the external environment. They are the most popularly used Transmission Media and are also the least expensive, and they are lightweight and simple to install while supporting a wide range of network types. The frequency range for twisted pair cable ranges from 0 to 3.5KHz.The number of turns per foot determines the degree of reduction in noise interference. Increasing the number of turns per foot decreases the noise interference.
Twisted pair cable is also classified into two types:
Unshielded Twisted Pair Cable
Shielded Twisted Pair Cable
Let us discuss about them in detail.
Unshielded Twisted Pair Cable
UTP stands for Unshielded Twisted Pair cable. UTP cable is a 100-ohm copper cable that consists of 2 to 1800 unshielded twisted pairs surrounded by an outer jacket. They do not have any metallic shield. This makes the cable smaller in diameter but unprotected against electrical interference. The twist helps to improve its immunity to electrical noise and EMI. They are made up of two or four pairs of twisted cables.
They are of 5 types: Category 1: They are used for telephone lines with low-speed data. Category 2: Supports up to 4Mbps. Category 3: Supports up to 16Mbps. Category 4: Supports up to 20Mbps and can be used for long-distance communication. Category 5: Supports up to 200Mbps.
Advantages of Unshielded Twisted Pair Cable
Easy to set up and install.
Flexible and low-cost
It has a high-speed capacity
It has a 100-meter limit.
Short-distance transmission due to attenuation.
Sensitive to external interference.
Disadvantages of Unshielded Twisted Pair Cable
Limited bandwidth than Coaxial Cable
Lesser protection from interference.
Susceptible to noise and cross-talk.
They can only be used for shorter distances because of attenuation.
Shielded Twisted Pair Cable
STP stands for Shielded Twisted Pair cable. STP Cabling is twisted-pair cabling with additional shielding to reduce crosstalks and other forms of electromagnetic interference (EMI). This cable has a metal foil covering which encases each pair of insulated conductors. A metal casing prevents electromagnetic noise penetration.
Advantages of Shielded Twisted Pair Cable
It has better performance at a higher data rate than UTP.
It eliminates crosstalk.
Its performance is adequate.
It can be used for Analog and Digital transmission both.
It increases the signaling rate.
It increases the pace of signaling.
It has a higher capacity than protected twisted pair.
Disadvantages of Shielded Twisted Pair Cable
It is more expensive and bulky than UTP and coaxial cable.
It has a higher attenuation rate.
It is comparatively difficult to manufacture and install.
Coaxial Cable
Coaxial cable, also known as coax, consists of an inner conductor surrounded by a concentric conducting shield. Coaxial Cables have an outer plastic covering containing an insulation layer made of PVC or Teflon and two parallel conductors, each having a separate insulated protection cover. The coaxial cable transmits information in baseband mode(dedicated cable bandwidth) and Broadband mode(cable bandwidth is split into distinct ranges). Cable TVs and analog television networks widely use Coaxial cables.
There are some advantages of using baseband coaxial cable:
Baseband coaxial cable has a high bandwidth, which means it can transmit data at high speeds.
Baseband coaxial cable is less susceptible to electromagnetic interference (EMI) than other types of cables.
Baseband coaxial cable can transmit data over longer distances than twisted-pair cables.
Baseband coaxial cable is highly durable and resistant to damage from physical stress or harsh environments.
Baseband coaxial cable is relatively easy to install, as it requires fewer connectors and is less complex than other types of cables.
Disadvantages of Baseband Coaxial cable
Along with its advantages, baseband coaxial cable also has some disadvantages:
While baseband coaxial cable can transmit data over longer distances than twisted-pair cables, it still has a limited distance capability.
Baseband coaxial cable is thicker and less flexible than other types of cables, which can make it difficult to install, particularly in tight spaces or around corners.
Baseband coaxial cable is more expensive than other types of cables, such as twisted-pair cables.
Baseband coaxial cable is vulnerable to moisture and other environmental factors, which can cause signal degradation and other issues.
Baseband coaxial cable is not compatible with all types of devices or systems, which can limit its usefulness in certain applications.
Broadband Coaxial Cable
This is accomplished by using analog transmission over conventional cable television wiring. It sends several signals at the same time at various frequencies. When compared to Baseband Coaxial Cable, it covers a larger region.
Advantages of Broadband Coaxial cable
There are some advantages of using broadband coaxial cable:
Broadband coaxial cable has a high bandwidth, transmitting data at high speeds.
Broadband coaxial cable is thinner and more flexible than baseband coaxial cable, which makes it easier to install, particularly in tight spaces or around corners.
Broadband coaxial cable is less susceptible to electromagnetic interference (EMI) than other types of cables.
Broadband coaxial cables can transmit data over longer distances than twisted-pair cables.
Disadvantages of Broadband Coaxial cable
There are some disadvantages of using broadband coaxial cable:
While broadband coaxial cable can transmit data over longer distances than twisted-pair cables, it still has a limited distance capability.
Broadband coaxial cable is not compatible with all types of devices or systems, which can limit its usefulness in certain applications.
Broadband coaxial cable can experience signal loss or attenuation, particularly over longer distances or when multiple devices are connected to the same cable.
Broadband coaxial cable is vulnerable to moisture and other environmental factors, which can cause signal degradation and other issues.
Broadband coaxial cable can be difficult to troubleshoot when problems arise, particularly when multiple devices are connected to the same cable.
Fibre Optic Cable
A fiber optic cable is a cable that uses electrical signals for communication. A fiber optic is a cable that holds the optical fibers coated in plastic used to send the data by light pulses. The plastic coating protects the optical fibers from heat, cold, and electromagnetic interference from other types of wiring. Fiber optic cables provide faster data transmission than copper wires.
Advantages of Fibre Optic Cable
Fiber optic cable offers high-speed transmission.
They are not affected by any electromagnetic interference.
Fiber optic cables are immune to attenuation and do not require regenerating signals even after 50+ km.
They are lighter in weight and cannot be tapped easily.
They are resistant to corrosive materials
Disadvantages of Fibre Optic Cable
Fiber optic cables are costly and difficult to install and maintain.
They are unidirectional and provide one-way communication. To have bidirectional communication, you have to install two cables.
They are fragile compared to standard cables.
Applications of Fibre Optic Cable
Telecommunications companies use optical fiber to transmit telephone signals, Internet communication, and cable television signals.
They are also used in other industries, including medical, defense, government, industrial and commercial.
In addition to serving the purposes of telecommunications, it is used as light guides, for imaging tools, lasers, hydrophones for seismic waves, SONAR, and as sensors to measure pressure and temperature.
Frequently Asked Questions
What is the difference between guided and unguided transmission?
Guided transmission media use physical paths like cables and optical fibers to direct signals, ensuring reliable and high-quality communication. Unguided transmission, on the other hand, involves wireless communication through air or vacuum, using radio, microwave, or infrared signals, offering flexibility and mobility.
What are the different types of guided media?
Different types of guided media for data transmission include twisted pair cables, coaxial cables, fiber optic cables, parallel wires, ribbon cables, microwave and infrared transmission, and underground/underwater cables.
What is guided and unguided?
Guided media are physical pathways, like cables, that direct data signals through a specific route. Unguided (wireless) media transmit data through the air without a physical path, using radio waves or microwaves.
What is an example of transmission media?
An example of transmission media is fiber optic cables, which use optical fibers to transmit data as light signals over long distances, offering high bandwidth and low signal loss.
Conclusion
In this article, we have extensively discussed ‘Guided Transmission Media’ and their types.Guided transmission media, also known as wired or physical transmission media, are the physical pathways or cables that enable the transmission of data signals over specified routes.
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