Guided Media in Computer Network: Types, Applications, Advantages, Disadvantages

Guided media, also referred to as bounded media, involves the transmission of signals through physical pathways or conduits connecting one machine to another. These pathways are typically constructed using twisted-pair, coaxial, or fiber-optic cables.

Guided media is often called wired or bound transmission media because it relies on physical linkages to guide and restrict the signals as they travel along a specific path. This method provides a controlled environment for the signals and helps ensure their reliable transmission from one point to another.

What is Guided Media in Computer Networks?

▪ In computer networking, guided media is a physical medium through which signals are transmitted. The signals are directed and confined in a narrow pathway using physical links.

▪ Guided media, also known as bounded or wired media, refers to any physical medium or pathway that is used to transmit signals or information from one point to another in a communication system.

▪ A guided media provides a controlled environment for the propagation of electromagnetic waves or signals. In guided media, the signals are confined within the physical medium, which provides a more controlled and secure transmission environment compared to wireless or unguided media.

▪ However, guided media typically have limited transmission distances, higher installation costs, and may require additional equipment for signal amplification or regeneration over long distances.

Read Also: Computer Languages: Types, Generations, Facts, Major Terms & Examples

Read Also:  Web Browser, History, Types, Function, Features, and More

Read Also:   Types of Operating Systems PDF

Read Also:    Storage Devices of Computer, Definitions, Types, and Examples

Types of Guided Media

▪ There are three main types of guided media:

▪ Twisted Pair Cable
▪ Coaxial Cable
▪ Fiber Optic Cable

Twisted Pair Cable

▪ This is one of the most widely used types of guided media for both analog and digital communication. It consists of two or more insulated copper wires or conductors that are twisted together. This helps to reduce interference from other external electrical signals. Twisted pair cables are used for a variety of applications, including Ethernet Networks, telephone systems, and VoIP.

Types of Twisted Pair Cable

▪ There are several types of twisted pair cables available for different applications. The two main types are unshielded twisted pair (UTP) and shielded twisted pair (STP) cables.

▪ UTP cables are commonly used in Ethernet networks for voice and data communication. They are cost-effective, flexible, and easy to install. On the other hand, STP cables have an additional metallic shield around the twisted pairs, providing better protection against electromagnetic interference (EMI) and crosstalk.

Unshielded twisted pair (UTP)

▪ UTP cables are the most common type of twisted pair cables used in Ethernet networks. It consists of two or more insulated copper conductors that are twisted together. UTP cables are used for a variety of applications, including Ethernet, telephone, and VoIP.

▪ They are widely used for voice and data communication and come in different categories, including Cat5e, Cat6, and Cat6a. UTP cables are affordable, flexible, and easy to install. However, they offer limited protection against external electromagnetic interference.

Advantages of Unshielded Twisted Pair (UTP) Cables

Cost-effective
UTP cables are relatively inexpensive compared to other types of networking cables, making them a cost-effective choice for many applications.

Easy installation
UTP cables are flexible and easy to install. They can be easily terminated and connected to network devices without requiring specialized tools or expertise.

Availability
UTP cables are widely available and come in various categories to meet different bandwidth and performance requirements.

Compatibility
UTP cables are compatible with most networking equipment and can be used in a wide range of applications, including Ethernet networks, telephone systems, and more.

Support for various data rates
With advancements in UTP cable categories, they can support data transmission at different speeds, ranging from 10 Mbps up to 10 Gbps or higher.

Disadvantages of Unshielded Twisted Pair (UTP) cables

Susceptibility to interference
UTP cables are more prone to external electromagnetic interference (EMI) and radio frequency interference (RFI) compared to shielded cables. This can result in data transmission errors and reduced performance.

Limited distance
UTP cables have a limited maximum transmission distance, especially for higher data rates. As the distance increases, signal quality and performance may degrade.

Crosstalk
UTP cables can suffer from crosstalk, which is the interference between adjacent pairs of wires within the cable. This can impact signal integrity and cause data errors.

Lower bandwidth compared to fiber optic cables
UTP cables have limited bandwidth compared to fiber optic cables, which can support much higher data rates over longer distances.

Limited future scalability
While UTP cables have seen advancements in performance with higher categories, they have limitations in terms of scalability for future technologies that require even higher bandwidths.

Applications of Unshielded Twisted Pair (UTP)

Unshielded Twisted Pair (UTP) cables have a wide range of applications across different industries. Some common applications of UTP cables include:

Ethernet Networks
UTP cables are extensively used in Ethernet networks for data transmission. They are commonly used in offices, homes, and commercial buildings to connect computers, routers, switches, and other network devices.

Telephone Systems
UTP cables are commonly used for telephone systems, both for voice communication and data transmission. They are used to connect telephone lines, extensions, and PBX (Private Branch Exchange) systems.

Video Surveillance Systems
UTP cables are widely used in video surveillance systems, such as CCTV (Closed-Circuit Television) installations. They are used to transmit video signals from security cameras to recording devices or monitoring stations.

Audio Systems
UTP cables can be used for audio applications, such as connecting speakers, microphones, and other audio equipment. They are commonly used in sound systems for events, conferences, and entertainment venues.

Home Networking
UTP cables are commonly used for home networking to connect devices like computers, gaming consoles, smart TVs, and streaming devices. They enable high-speed internet connectivity and data sharing within a household.

Industrial Automation
UTP cables find applications in industrial environments for connecting devices in automation systems, process control systems, and PLC (Programmable Logic Controller) networks.

Building Automation
UTP cables are used in building automation systems to connect sensors, control panels, HVAC (Heating, Ventilation, and Air Conditioning) systems, and lighting systems for efficient building management.

Access Control Systems
UTP cables are used in access control systems to connect card readers, biometric devices, and control panels for secure entry and access management in buildings.

Data Centers
UTP cables are used in data centers for connecting servers, switches, storage devices, and networking equipment. They provide reliable and high-speed data transmission within the data center infrastructure.

Multimedia Systems
UTP cables can be used for multimedia applications, including connecting audio/video equipment, multimedia consoles, and gaming devices.

These are just some of the many applications of Unshielded Twisted Pair (UTP) cables. The versatility and cost-effectiveness of UTP cables make them a popular choice for various data and communication needs.

Shielded Twisted Pair (STP) Cable

STP cables are similar to UTP cables but with an additional metallic shield around the twisted pairs. The shield helps to reduce electromagnetic interference (EMI) and crosstalk. STP cables are commonly used in industrial environments where there is a higher likelihood of EMI. They are also used in some high-speed networking applications. STP cables are more expensive than UTP cables, but they are also more reliable.

Advantages of Shielded Twisted Pair (STP) cables:

Improved signal quality
Shielding helps to reduce electromagnetic interference (EMI) and external noise, resulting in better signal quality and higher data transmission rates.

Enhanced security
The shielding provides additional protection against eavesdropping and unauthorized access to the data transmitted through the cable.

Longer cable runs
STP cables can support longer cable runs compared to unshielded cables without significant signal degradation.

Disadvantages of Shielded Twisted Pair (STP) cables:

Cost
STP cables are generally more expensive than unshielded cables due to the additional shielding material and complexity of the construction.

Bulkiness and rigidity
The shielding makes STP cables thicker and less flexible, which can be a disadvantage in situations where cable management and installation flexibility are important.

Applications of Shielded Twisted Pair (STP) Cables

Industrial environments
STP cables are commonly used in industrial settings where there is a higher risk of electromagnetic interference and the need for reliable data transmission.

Data centers
STP cables are often used in data centers to ensure secure and high-speed data transmission between servers, switches, and storage devices.

Telecommunications
STP cables are used in telecommunication systems, such as telephone networks and high-speed internet connections, to minimize signal loss and interference.

Medical equipment
STP cables may be used in medical environments to ensure accurate and reliable data transmission between various medical devices and systems.

The following table compares the two types of twisted pair cables:

Feature	UTP	STP
Cost	Less expensive	More expensive
Reliability	Less reliable	More reliable
Applications	Ethernet, telephone, VoIP	Ethernet, telephone, VoIP, where interference is a concern

▪ Apart from these two main types, there are other variations such as screened twisted pair (ScTP), foiled twisted pair (FTP), and screened foiled twisted pair (SFTP) cables. ScTP cables have an overall metallic foil shield, FTP cables have individual foil shielding for each twisted pair, and SFTP cables combine both individual and overall shielding. These variations offer different levels of EMI protection and crosstalk reduction, catering to specific high-performance applications and environments.

Screened Twisted Pair (ScTP)

▪ Screened twisted pair (ScTP) is a variety of twisted pair cable that combines an additional foil shield surrounding each individual twisted pair. This shield serves to safeguard the cable against electromagnetic interference (EMI) and radio-frequency interference (RFI).

▪ ScTP finds extensive application in environments characterized by high EMI or RFI levels, such as industrial settings or areas near power lines. Although similar to unshielded twisted pair (UTP) cables, ScTP boasts several advantages.

▪ The foil shield helps in minimizing crosstalk, a form of interference that can arise between adjacent twisted pairs. Additionally, the foil shield provides protection against EMI and RFI, which can potentially lead to data corruption or cable damage.

▪ While ScTP cable tends to be more costly than UTP cable, it offers several benefits that make it an ideal choice for environments prone to significant EMI or RFI. If you require a cable resistant to interference, ScTP presents an excellent option.

Foiled Twisted Pair (FTP)

▪ Foiled twisted pair (FTP) is a type of twisted pair cable featuring an overall foil shield that surrounds the twisted pairs. This shield provides protection against electromagnetic interference (EMI) and radio-frequency interference (RFI). FTP cables are commonly utilized in environments with high EMI or RFI levels, such as industrial settings or areas near power lines.

▪ FTP cables share similarities with unshielded twisted pair (UTP) cables, but they possess distinct advantages. The foil shield effectively reduces crosstalk, which is a form of interference that may arise between adjacent twisted pairs. Furthermore, the foil shield acts as a safeguard, shielding the cable from EMI and RFI that can potentially cause data corruption or cable damage.

Screened Foiled Twisted Pair (SFTP)

▪ SFTP cables combine the features of both STP and FTP cables. They have individual shielding for each twisted pair and an overall metallic shield around all the twisted pairs. SFTP cables provide excellent protection against crosstalk and EMI and are commonly used in high-speed networking and data center environments.

These are the main types of twisted pair cables commonly used in communication networks. The choice of cable type depends on factors such as the required data transmission speed, distance, level of electromagnetic interference, and specific application requirements.

Categories of Unshielded Twisted Pair (UTP) Cables

▪ Category 1 (Cat 1): Primarily used for telephone communication and does not support data transmission.

▪ Category 2 (Cat 2): Capable of transmitting data at speeds up to 4 Mbps. Mostly used for token ring networks.

▪ Category 3 (Cat 3): Supports data transmission at speeds up to 10 Mbps. Commonly used for Ethernet networks and telephone systems.

▪ Category 4 (Cat 4): Capable of transmitting data at speeds up to 16 Mbps. Less common and mainly used for Token Ring networks.

▪ Category 5 (Cat 5): Supports data transmission at speeds up to 100 Mbps (Fast Ethernet). Widely used for Ethernet networks and phone systems. Cat 5e (enhanced) is an improved version with better performance and reduced crosstalk.

▪ Category 6 (Cat 6): Provides improved performance and supports data transmission at speeds up to 1 Gbps (Gigabit Ethernet). Suitable for high-speed data networks.

▪ Category 6a (Cat 6a): Augmented version of Cat 6 with improved performance and supports data transmission at speeds up to 10 Gbps. Often used for high-performance applications and data centers.

▪ Category 7 (Cat 7): Offers even better performance and supports data transmission at speeds up to 10 Gbps or higher. Provides additional shielding for reduced interference.

Category	Data Transmitting Speed	Use
Cat 1	1 Mbps	Voice grade
Cat 2	4 Mbps	Token ring networks
Cat 3	10 Mbps	Ethernet networks
Cat 4	16 Mbps	Ethernet networks
Cat 5	100 Mbps	Gigabit Ethernet networks
Cat 5e	1000 Mbps	Gigabit Ethernet networks
Cat 6	10 Gbps	10 Gigabit Ethernet networks
Cat 6a	10 Gbps	10 Gigabit Ethernet networks
Cat 7	100 Gbps	40 and 100 Gigabit Ethernet networks
Cat 8	400 Gbps	400 Gigabit Ethernet networks

▪ The choice of UTP cable category depends on the desired data transmitting speed and the type of network that will be used. For example, Cat 5e cable is typically used for Gigabit Ethernet networks, while Cat 6 cable is typically used for 10 Gigabit Ethernet networks.

▪ It is important to note that UTP cables are not all created equal. There are different grades of UTP cables, and the quality of the cable can affect the data transmitting speed. It is important to purchase high-quality UTP cables to ensure that they will perform well.

Coaxial Cable

▪ Coaxial cable consists of a central conductor, a surrounding insulating layer, a metallic shield, and an outer insulating layer. The shield helps to protect the signal from interference. It is commonly used for cable television (CATV) and broadband Internet connections. Coaxial cables provide higher bandwidth and better noise immunity compared to twisted pair cables.

▪ Coaxial cable is a type of guided media that consists of a central conductor, an insulating layer, a metallic shield, and an outer insulating layer. Here are the advantages, disadvantages, and applications of coaxial cable:

Advantages of Coaxial Cable

Bandwidth and Data Transfer
Coaxial cable offers higher bandwidth capabilities compared to twisted pair cables, allowing for the transmission of large amounts of data at high speeds.

Longer Transmission Distances
Coaxial cable can transmit signals over longer distances without significant signal degradation, making it suitable for applications that require long-distance communication.

Resistance to Noise and Interference
The metallic shield in coaxial cable provides excellent protection against electromagnetic interference (EMI) and external noise, ensuring a more reliable and stable signal transmission.

Versatility
Coaxial cable is compatible with various communication protocols and can support multiple services simultaneously, including television, internet, and telephone signals.

Disadvantages of Coaxial Cable

Bulkiness and Rigidity
Coaxial cable is thicker and less flexible compared to other types of guided media, which can make installation more challenging, especially in tight spaces or complex network configurations.

Cost
Coaxial cable can be more expensive than twisted pair cables, particularly for higher-grade variants or when longer lengths are required.

Limited Future-Proofing
While coaxial cable provides higher bandwidth than twisted pair cables, it may not support the same level of scalability and future upgrades as fiber optic cables.

Applications of Coaxial Cable

Cable Television (CATV)
Coaxial cable is extensively used for transmitting cable TV signals from the service provider to subscribers’ homes or businesses.

Broadband Internet
Coaxial cable is commonly used in cable internet connections, allowing for high-speed data transfer.

CCTV and Surveillance Systems
Coaxial cable is often used in closed-circuit television (CCTV) and surveillance systems to transmit video signals from cameras to monitoring equipment.

High-Frequency Applications
Coaxial cable is suitable for high-frequency applications such as radio frequency (RF) transmission, satellite communication, and microwave systems.

Ethernet Networks
Although coaxial cable has been largely replaced by twisted pair and fiber optic cables in Ethernet networks, it was previously used in older Ethernet standards such as 10BASE2 and 10BASE5.

Fiber Optic Cable

▪ Optical fiber is a type of guided medium that uses thin strands of glass or plastic fiber to transmit data in the form of light signals. It offers high data transfer rates, long-distance transmission capabilities, and immunity to electromagnetic interference.

▪ Optical fibers are extensively used in telecommunications networks, internet backbone connections, and high-speed data transmission systems. Here are the advantages, disadvantages, and applications of fiber optic cable:

Advantages of Fiber Optic Cable

High Bandwidth and Data Transfer
Fiber optic cables provide significantly higher bandwidth capabilities compared to other types of guided media (Coaxial and Twisted Pair Cable), allowing for the transmission of large amounts of data at extremely high speeds.

Long Transmission Distances
Fiber optic cables can transmit signals over long distances without experiencing significant signal degradation, making them ideal for long-haul and high-capacity communication networks.

Immunity to Electromagnetic Interference
Unlike copper-based cables, fiber optic cables are immune to electromagnetic interference (EMI) and do not experience signal loss due to external factors such as nearby power lines or electrical noise.

Lightweight and Compact
Fiber optic cables are thinner and lighter than copper cables, making them easier to install and manage. They also occupy less physical space.

Security
Fiber optic cables are difficult to tap into, providing enhanced security for transmitting sensitive data. They do not emit electromagnetic signals that can be intercepted, making them more secure against eavesdropping.

Disadvantages of Fiber Optic Cable

Higher Cost
Fiber optic cables can be more expensive than other types of guided media, primarily due to the cost of manufacturing and installation equipment. However, the costs have been reducing over time as the technology becomes more widespread.

Fragility
Fiber optic cables are more fragile compared to copper cables and can be easily damaged if bent or subjected to excessive tension. Proper handling and installation techniques are required to avoid signal loss.

Limited Accessibility
Fiber optic cables require specialized equipment and expertise for installation, maintenance, and repairs, which may limit accessibility in certain areas or situations.

Incompatibility with Existing Infrastructure
Upgrading to fiber optic networks may require significant changes to the existing infrastructure, including replacing copper-based equipment and implementing new network components.

Applications of Fiber Optic Cable

Telecommunications Networks
Fiber optic cables are extensively used in long-distance telecommunication networks, such as undersea cables, fiber-to-the-home (FTTH) connections, and high-speed internet backbone connections.

Data Centers
Fiber optic cables are crucial for interconnecting servers, switches, and storage devices within data centers, providing high-speed and reliable data transmission.

Cable Television (CATV)
Fiber optic cables are increasingly used in CATV networks to transmit high-definition video and audio signals with minimal signal degradation.

Medical and Imaging Systems
Fiber optic cables are used in medical applications such as endoscopy, imaging systems, and laser surgery, where high-speed and reliable transmission of data and images is essential.

Industrial and Military Applications
Fiber optic cables are employed in industrial automation systems, control networks, and military communication systems due to their resistance to electromagnetic interference and secure data transmission capabilities.

▪ Fiber optic cables offer numerous advantages in terms of bandwidth, speed, security, and signal integrity, making them well-suited for various applications that require high-performance data transmission and reliability. However, the higher cost and specialized installation requirements should be taken into consideration when planning and implementing fiber optic networks.

Which type of Guided Media is best for data Transmission?

▪ The type of guided media that is best for a particular application will depend on a number of factors, including the cost, the reliability, and the distance that the signal needs to travel.

▪ Each type of guided media has its own advantages and disadvantages. Twisted pair cables are the least expensive type of guided media, but they are also the least reliable. Coaxial cables are more expensive than twisted pair cables, but they are also more reliable. Fiber optic cables are the most expensive type of guided media, but they are also the most reliable.

Structure of a Twisted Pair Cable

Part	Description
Conductor	Multiple pairs of insulated copper wires twisted together
Insulation	Protective layer of insulation around each individual wire
Twisting	Individual wire pairs twisted together to reduce crosstalk and electromagnetic interference
Shielding (Optional)	Metallic or foil shield around the twisted pairs to provide additional protection against interference
Jacket	Outer protective layer that provides physical strength and durability

▪ The structure of a twisted pair cable can vary depending on the type of cable and the application. However, all twisted pair cables share the same basic components.

Comparison between Twisted Pair Cable, Coaxial Cable, and Fiber Optic Cable.

Feature	Twisted Pair Cable	Coaxial Cable	Fiber Optic Cable
Construction	Multiple pairs of insulated copper wires twisted together	Inner conductor surrounded by insulating layer, metallic shield, and outer insulating layer	Thin strands of glass or plastic fibers that transmit light signals
Bandwidth	Lower bandwidth compared to coaxial and fiber optic cables	Moderate to high bandwidth depending on cable type	Very high bandwidth
Transmission Speed	Lower transmission speed compared to coaxial and fiber optic cables	Higher transmission speed than twisted pair cables	Very high transmission speed
Interference	Prone to electromagnetic interference	Less susceptible to interference compared to twisted pair cables	Immune to electromagnetic interference
Distance	Short to medium distance transmission	Medium distance transmission	Long distance transmission
Applications	Most commonly used for Ethernet networks, telephone systems	Used for cable TV, CCTV systems, high-speed data networks	Used for long-distance communication, high-speed internet, telecommunication networks

Why Guided Media is Better than Unguided Media?

▪ Guided media is generally considered to be better than unguided media for a number of reasons. Such as –

▪ Security: Guided media is more secure than unguided media because the signals are contained within a physical medium, making them less susceptible to eavesdropping.

▪ Performance: Guided media can typically support higher data rates than unguided media. This is because the signals are not subject to the same interference and attenuation as they are when they travel through the air.

▪ Scalability: Guided media is more scalable than unguided media. This is because it is easier to add additional nodes to a network that uses guided media.

▪ Cost: Guided media is typically less expensive than unguided media. This is because it does not require the use of expensive radio transmitters and receivers.

▪ However, there are some drawbacks to using guided media.

▪ Inflexibility: Guided media is less flexible than unguided media. This is because it is difficult to move nodes around in a network that uses guided media.

▪ Installation: Guided media can be more difficult to install than unguided media. This is because it requires the use of physical cables.

▪ Environmental factors: Guided media can be more susceptible to environmental factors, such as moisture and electromagnetic interference.

▪ Overall, guided media is a better choice for most applications that require high security, performance, scalability, and cost-effectiveness. However, unguided media may be a better choice for applications that require flexibility and ease of installation.

▪ Here is a table that summarizes the key differences between guided media and unguided media:

Feature	Guided Media	Unguided Media
Security	Higher	Lower
Performance	Higher	Lower
Scalability	Higher	Lower
Cost	Lower	Higher
Flexibility	Lower	Higher
Installation	More difficult	Easier
Environmental factors	More susceptible	Less susceptible

▪ Ultimately, the best choice of transmission medium will depend on the specific needs of the application.

More Computer Awareness Posts