Answer

Transmission Media

Abstract

Computer communications entail encoding data into some type of energy and disseminating this across a transmission medium. This paper discusses the characteristics of various transmission media and future trends. Transmission media are essential to create a computer network because they are the material paths between a mast and a recipient. Examples of companies involved in transmission media include Verizon, AT&T, CenturyLink, Netflix, and Comcast.  Transmission media is a communication pathway that transmits communication from disseminator to recipient using various kinds of wires or waves to diffuse data. Typically, data is conveyed via electric or electromagnetic pointers. Transmission media’s main functionality is to dispatch the information in bits form via LAN known as local area network. An electromagnetic signal is a sequence of electromagnetic energy beats at different rates. Hence, these signs can be conveyed through a vacuum, copper wires, atmosphere, water, and optical fibers. The signal and medium features ascertain data transmission quality and features.  Various transmission media have different features like maintenance, delay, ease of installation, bandwidth, and cost. Despite the benefits linked with transmission media, research is still ongoing to further enhance the existing different transmission media, and to resolve some of the challenges confronting them.

 

 

 

 

 

 

 

Transmission Media

This paper discusses the two main categories of transmission media, which are guided and unguided media, and the history and future trends of these respective media forms in this industry. In data communication, a transmission medium facilitates broadcast of signs for telecommunication functions. Signals are characteristically enforced on a wave that is apt for the preferred medium. For instance, data can regulate sound, and a sound transmission channel can be air, although objects and liquids can also function as broadcast channel. For electromagnetic waves like radio waves and light, vacuum or air comprises a suitable transmission medium. This paper aims to highlight the different forms of transmission media utilized for physically disseminating signals from one source to another. Likewise, the paper discusses the primary operation method of each of these transmission media forms, introduces the different system components, and explains the application for every kind. The discussion starts with guided media types, namely, fiber-optic cables, twisted pair, and coaxial copper. Coaxial cable is utilized for radiofrequency and data dissemination. The cable is extraordinarily reliable regarding its electrical attributes at below 4 GHz frequencies, and this makes the cable prevalent as a linkage between radio and its mast. Twisted-pair cables are used extensively in transmitting data at an adequate rate of up to100 Mbps in particular network architecture. Likewise, the wireless systems such as infrared, microwave radio systems, and satellite systems transmission need no explicit bearer and emit their signals as electromagnetic waves are examined.

 

Forms/Types of Transmission Media

Figure I: Forms of Transmission Media fromTransmission Media by Abbas Mirry (2020, p.4).

Guided Media

Guided transmission media contains cables or wires via which data is conveyed and is termed guided because it offers a concrete pathway via which information is transmitted. Examples of guided media comprise twisted pairs, coaxial cables, and fiber-optic cables.

Twisted Pair

Twisted pair cables were mostly created for voice broadcasts. Twisted pair is prevalently utilized channel in networking since it is more flexible, lighter, affordable, simple to install, and offers higher velocities than coaxial cables (Miry, 2020). Twisted pair is of two types; unshielded twisted pair (UTP) and shielded twisted pair (STP). The UTP has four pairs of copper wires that are existing in the plastic sheath. The wires are warped to safeguard them from interloping. The only security accessible for UTP is a plastic casing that is thin in size.

Figure II: UTP cable. From Transmission Media by Abbas Mirry (2020, p.6)

The STP is mostly utilized in high- rapidity systems. The main variance between UTP and STP is that STP uses metallic armor in enveloping the wires (Miry, 2020). The tapping aspect is covered by the metallic cover than UTP does. The STP cables are numbered, and the higher numbering means an improved obstacle deterrence. Several computer networks are compatible with CAT 3 or CAT 5.

Likewise, both UTP and STP can be tapped. Hence, at minimum, core devices should be secured from unauthorized access, and cables must be marked clearly and accessible for visual inspection. One evident drawback of open-air signal broadcast technologies is the absence of precisely defined limits (King & Bittlingmeier, 2003). Wired networks have a secure physical signal path. In broadcast, however, it is theoretically likely for someone to eavesdrop to the receiver frequency of your transmission without noticing it.

 

Figure III: Difference between UTP and STP Cable. From Transmission Media by Abbas Mirry, (2020, p.10).

History and Future Projections

Currently, traditional optical networks cannot adapt to fast online data service growth because of the dynamic bandwidth allocation volatility. Hence these networks depend mostly on network connectivity manual configuration, which is time-consuming and cannot entirely adapt to the modern network demands (Dasari, 2015). Hence, optical intelligence network is an incoming tendency in optical network creation. Another future drift will be the current semi-conductor lasers extension to a wide lasing wavelengths variety. Also, single style tunable lasers are useful for future consistent optical structures.

Advantages and Disadvantages

Advantages

            Twisted pair cables can be utilized in dispatching both analog and digital data. The traveled distance and wire width determine the bandwidth. However, various megabits per second can be attained for a few kilometers in several cases. Because the twisted pair is the oldest data transmission method, a trained workforce for maintenance and repairs is readily available. It is comparatively easy to install and terminate, and an affordable transmission media for short distances. The entire network is not affected by small damage of a twisted pair cable.

Disadvantages

Twisted pair can pick noise signs which outcome in enormous error tempos when the line stretch surpasses one hundred meters. Also, the twisted pair has high attenuation and provides poor security and is easily tapped. Twisted pair can break easily because of its thin size.

Coaxial Cable

The coaxial cables have a focal copper conductor, encompassed by a sequestering layer, a conducting armor, and the outermost plastic covering. Hence, the inner copper cable has three insulation layers (Ketheeswaren et al., 2011). The coaxial cables have two basic data transmission modes: the baseband mode with devoted bandwidth, and the broadband mode with dispersed cable bandwidth. Coaxial cables are mostly used in Cable TV and analog TVs. Coaxial cables have better defiance to cross talk than twisted-pair cables and are primarily utilized in long-distance communication.  RG-59 and RG-6 are the widely used coaxial cable types. RG-59 has fewer shielding appropriate for short cable lengths and cable TV links (Miry, 2020). RG-6 insulation is better than RG-59 and is utilized for satellite TV and digital signal spread for better strength and stretched distances.

Since a single core wire does the electrical signal in coaxial cable, a person can simply tap it through cutting the sheath. This makes eavesdropping on discussions possible of all hosts linked to the segment since 10BASE-2 coaxial cabling executes broadband diffusion technology and imagines several hosts connected to the same wire (King & Bittlingmeier, 2003).

Figure IV: Coaxial Cable. From Transmission Media by Abbas Mirry, 2020, p.20.

History and Future Projections

The improvements done by the usage of coaxial cable have often been backed by different entities initiatives devoted to developing technical benchmarks by providing the necessary support to the demands that progress. Digital Video Broadcasting is among the primary standards. For several years, the coaxial network usage pattern stayed unaffected, with the end-user meant only to the information consumer (Sharma et al., 2013). This structure of operation started suffering from advanced changes linked with two new realities. Firstly, the user wanted to both watch TV with internet improvement and get data. The second was that new competitors came onboard, which necessitated the ability to interface with the user.

Presently, the profile of HFC networks usage endures to progress so that the existing channel occupation is primarily envisioned to reduce the analog TV channels transmission and standard description digital channels (Freeman, 2005). However, high-definition TV is already present in some countries. In the future, a high-definition TV role will be underlined together with video and data communication demand. Because of this forecast, the necessity for higher bandwidth is apparent, ensuing in the fact that the existing network capacity should be increased to handle the future demand.  

Advantages and Disadvantages

Advantages

Coaxial cable is less vulnerable to noise or interruption and is easy to wire and enlarge because of flexibility. Coaxial cable is affordable and permits higher transfer rates because it has enhanced shielding materials. Also, it is easy and affordable to install. Coaxial cable outer conductor is utilized to improve attenuation and shield efficiency. This can be enhanced more with the second foil’s usage called a jacket as a protective cover from the environment and makes it flame retardant.

Disadvantages

Coaxial cables are predisposed to lightning strikes and cover less distance than fiber optic cables. Security is the primary concern because tapping into the coaxial cable is secure. Installing coaxial cable over a long distance is costly because of the thickness and rigidity.

Fiber Optic

Optical fibers utilize light waves for broadcast and have no issues with EMI, Crosstalk, and attenuation. The cables are apt for video, voice, and data diffusion. Optical fibers are the safest of all the cable media (Senior & Jamro, 2009). It is challenging and costly to install and maintain them. Fiber optic cables have superior transmission rapidity, high bandwidth, and the signal can move longer distances when likened to coaxial and twisted pair cables. Although optical fiber cable cost is less likened to coaxial and twisted pair cables, the extra optical features necessary for fitting make fiber optic the priciest of all the wires.

 

 

 

Figure V: Optical Fiber Cable. From Transmission Media by Abbas Mirry (2020, p.28).

History and Future Projections

Modern global businesses demand quicker, more secure, and bigger communication systems capacity for their network operations. Rajpoot et al. (2017) state that fiber optic technology is anticipated to assume a significant role in this growth. Research is ongoing to enhance optical transmitter by developing optical transceivers implementing new and innovative modulation expertise. This will have notable chromatic diffusion and optimal sign to noise relation (OSNR) forbearance, which will be appropriate for ultra-long-haul communication structures (Shahraeini, Javidi, & Ghazizadeh, 2010). The global demand for amplified bandwidth accessibility has led to an appeal in creating multi-terabit optical networks. With the constant decrease in the fiber optic features cost, the convenience of higher bandwidth in the future is likely.

 

 

 

Types of Optical Fiber

Single Mode

The single-mode fiber utilizes a single beam of light. It permits communication over vast distances with enhanced transfer speed. It has a diameter of nine microns and only allows a single wavelength and conduit for light to travel, which significantly reduces light reflection and lessens attenuation. 

Multi-Mode

The multi-mode fiber which utilizes light rays within a single fiber cable. It has decreased length and travel rapidity and has a more significant bandwidth; however, signal strength is enfeebled.

Advantages of Fiber Optic

The bandwidth for fiber optic is enormous than metal cables, therefore, enabling the spread of broad information. The low power loss that fiber optic offer permits for longer transmission distances. It is hard to tap optical fiber since it does not generate electromagnetic energy. The cables are very safe while conveying or dispatching data. The wires are light, thin and use less space as likened to metal wires.

Disadvantages of Fiber Optic

It is difficult to splice optical fibers, and there is a loss of the fiber light because of scattering. Fiber optic has a restricted physical arc of cables, which can break when bent too much. It is costly to install optical fibers because a specialist is needed to fix them. The fiber optic can easily cut or be damaged during installation exercises because they are small. 

Unguided Media

Unguided media transport data in electromagnetic waves from that do not need any cables for transmission. This media’s primary features are that the signal can be conveyed through the air, less safe, and use long distances. The different types of unguided media are discussed below:

Microwave

Microwaves are electromagnetic waves with frequencies ranging from 1 and 300 GHz. Microwaves are unidirectional, and when a mast spreads micro-waves, they can be strictly absorbed. Such implies that broadcasting and getting masts should be allied. Microwave broadcast is line-of-sight because the mounted masts put on towers should face each other, and towers that are far apart should be very tall (Ketheeswaren et al., 2011). Walls are impenetrable when high-frequency microwaves are used, and this feature can be a drawback if receivers are in the building. The usage of specific components of the band needs the authority’s permission.  Microwaves are utilized in wireless LANs, mobile phones, and satellite networks.

 

Figure VI: Microwave Transmission. From Transmission Media by Abbas Mirry (2020, p.34).

Microwaves Unidirectional Antenna

Microwaves require unidirectional masts that send-out signs in one direction. Parabolic dish and Horn are the two forms of antennas utilized for microwave communications.

Figure VII: Unidirectional Mast. From Transmission Media by Abbas Mirry (2020, p.36).

The parabolic antenna operates like a funnel for capturing different waves and guiding them to a mutual point. Therefore, the signal has convalesced than it can be probable with a single-point recipient. A horn mast is similar to a large scoop (Ketheeswaren et al., 2011). Outbound broadcasts are aired up a stem and repelled outward in a sequence of thin analogous rays by the curved head. The Horn’s scooped shape collects the received transmission in a way comparable to the parabolic dish, and are bent down into the stem.

Pros of Microwave

Microwave radio systems can broadcast massive information quantities’ due to their higher frequencies. Likewise, they use repeaters in transmitting large data volumes over long distances and are free from any land acquisition because it does not need any land for cables installation. Microwave transmission offers secure communication in terrains as cable installation in the territory is a challenging job. 

Drawbacks of Microwave Transmission

The microwave communication system does not need physical cables or costly attenuation equipment for installation. Besides, weather changes can distort the signal. 

 

 

 

 

 

 

 

 

Types of Microwave Transmission

The two types of Microwave Transmission are terrestrial microwave and satellite microwave, as shown in the figure below:

Figure VIII: Types of Microwave Transmission. From Optical fiber communications by Senior and Jamro (2009, p.40).

Terrestrial Microwave

Terrestrial is a technology that spread a radio signal focused beam from one ground-centered microwave broadcast antenna to another. The terrestrial microwave frequency range is from 4-6 GHz to 21-23 GHz and supports 1 to 10 Mbps bandwidth (Miry, 2020). Environmental situations and antenna size impact attenuation, and it is costly because it needs a higher tower for a longer distance. Likewise, it is low-cost for a short-range.

 

 

 

 

Figure IX: Terrestrial Microwave. From Optical fiber communications by Senior and Jamro (2009, p.41).

Pros of Microwave Transmission

Terrestrial microwave is affordable than using cables and communication overseas can be attained by utilizing microwave transmission. It is free from any land acquisition because it does not need any land for cables installation. Microwave transmission offers secure communication in terrains as cable installation in the territory is a challenging job. 

Drawbacks of Microwave Transmission

The bandwidth allocation is restricted in the microwave transmission case. Any mischievous user can hold the sign in the air using its antenna.

Satellite Microwave

Satellite transmission is a space station that gets microwave signs from an earth-centered station, enhanced the signals, and disseminated the signals back over an extensive territory to several earth-centered stations (Miry, 2020).

Figure X: Satellite Transmission. From Optical fiber communications by Senior and Jamro, (2009, p.44).

Advantages of Satellite Transmission

The geographical coverage area is big, mostly for sparsely populated regions when using satellite transmission. It is easy to establish wireless and mobile communication independent of location. Satellite transmission is utilized in different applications like radio/TV signal dissemination, wireless and mobile communication, and weather forecasting.

Drawbacks of Satellite Transmission

It is costly to design and invest in satellite and repairing and maintenance is not easy. It is expensive, and satellite needs regular supervision and control to remain in orbit. The satellite life is roughly twelve to fifteen years, and therefore, another satellite launch should happen before it becomes non-operational.

Radio Wave

Radio waves are the electromagnetic waves spread in all the free space directions. Radio waves are Omni-directional, and the frequencies range from 3 kHz to 1GHz (Miry, 2020). Mostly these waves are utilized in FM and AM radio stations, paging, and cordless phones.

Figure XI: Radio wave. From Optical fiber communications by Senior and Jamro (2009, p.50).

 

Advantages of Radio Wave

Radio waves are simple to generate and penetrate in buildings, and also the waves travel long distances. Hence AM radio can get signals in a building (Freeman, 2005). Likewise, this can be disadvantaged since communication cannot be isolated inside or outside a building. Therefore, due to this, governments stringently legislate the usage of radio transmitters. When the frequencies are not very high, radio waves do not require Line of Site.

Disadvantages of Radio Wave

Radio waves cannot transmit massive data simultaneously due to low frequency.

Infrared

Infrared waves are utilized in minimal distance communication because the high frequencies cannot infiltrate walls (Miry, 2020). Infrared is used for short-range communication like data transfer between two mobile phones, TV remote function, and a transfer of data between a computer and a printer. Infrared transmission is undependable outside the building since the sunrays will interfere with the infrared waves.

Signal spread spectrum technology has made wireless transmission safer but only to a specific point. Infrared transmissions are perceived as more reliable than radio transmission because the communication devices utilize invisible light continuum ranges and need a direct sightline. It makes it complicated to eavesdrop in communication (Imai, Kobara, & Ghulam Rahman, 2005). However, technology itself is not technically insusceptible to eavesdropping because infrared signals can be recorded with cameras having infrared filters (King & Bittlingmeier, 2003). Therefore, the only method to ensure wireless communication security is to utilize robust authentication algorithms like PKI and encrypting all communications.

Advantages of Infrared

Due to lower power usage, infrared devices batteries last longer. It offers remarkable stability over time and offers secured communication because of line-of-sight communication mode. The infrared sensor accuracy is not affected by oxidation, and it is affordable

Disadvantages of Infrared

Hard objects like walls affect the frequency. Also, High power infrared waves can damage the eyes. Infrared waves operate effectively in a shorter range, and therefore the performance reduced with longer distances. 

Conclusion

The primary driving force behind prevalent usage of transmission media is because of the high and speedily growing customer and business-related demand for more telecommunication volume and internet services. Hence, fiber optic technology is adept at offering the needed information capability. The transmission media is ever-evolving. More work needs to be done in supporting the demand for speedy data frequencies, higher switching methods, and more intelligent network designs that can robotically transform vigorously in reaction to traffic models and is also cost-efficient.