Optical Fiber vs. Coaxial Cable

Coaxial Cable is a pure copper or copper-coated wire surrounded by insulation material with aluminum covering used to transmit telephone, television and data signals. Fiber Optic cable is used to deliver the same types of signals but carry much wider bands of frequencies. It is made of thin and pliable tubes of glass and plastic.

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The computers and other digital devices transmit the information from one to another device in the kind of signals and with a transmission media. The transmission media can be basically categorized into two types guided and unguided.

Unguided media is a wireless communication that carries electromagnetic waves by taking advantage of air as moderate and without needing a physical conductor. Guided media require a physical medium to transmit signals such as cables. Guided media is categorized in three ways twisted pair cable, coaxial cable and fiber-optic cable. The report describes the difference between optical fiber and coaxial cable.

Basically, the optical fiber is a guided media which transmits the signals from one device to another in the form of light (optical form). Whereas coaxial cable transmits the signals in electric form.

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Comparison Chart

BasisOptical FiberCoaxial Cable
BasicIn optical fiber transmission of the signals are in light form.In coaxial cable transmission of the signals are in electrical form.
EfficiencyHighLow
Losses in cableDispersion, bending, absorption and attenuation.Resistive, radiated and dielectric loss.
Composition of the cablePlastics and GlassMetal foil, Plastic and metal wire (Normally copper).
Bending effectCan affect the signal transmission.Bending of wire does not affect the signal transmission.
CostHighly expensiveLess expensive
Installation of the cableDifficultEasy
Data transmission rate2 Gbps44.736 Mbps
External magnetic fieldDoesn’t affect the cableAffects the cable
Bandwidth providedVery highModerately high
Noise immunityHighIntermediate
The diameter of the cableSmallerLarger
The weight of the cableLighterHeavier comparatively
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What is Optical Fiber?

As stated before the optical fiber is a sort of guided media. It’s composed of glass, plastic and silica, where the signals are transmitted in the kind of light. Optical fiber employs the principle of total internal reflection to direct light through the station. The structural composition of an optical fiber comprises a glass or ultra-pure fused silica surrounded by a cladding of dense plastic or glass. The cladding is coated with a buffer either tight or loose, to protect it from moisture. Finally, the entire cable is then encased by an outer covering made by a substance like Teflon, plastic or fibrous plastic etc..

The density of both substances is maintained in such a manner that the light beam traveling through the center is mirrored off the cladding instead of refracted into it. In the optical fiber, the data is encoded in the shape of a light beam as a string of on and off flashes that signifies 1 and 0’s. Fiber optics cable consists of glass and is fragile that makes it tough to install. The repeater is installed at 2 km to 20 km depending on the sort of the fiber. There’s two kinds of optical fiber, multi-mode and single-mode. Multi-mode fiber has two variants, step-index and graded-index fiber. LED and lasers can be utilized as the light source of the optical cable.

Optical Fiber

Losses

In Optical fiber cable, the reduction of energy takes place once the light is hauled from 1 area to another which is referred to as attenuation. The attenuation is caused when the subsequent phenomenon occurs absorption, dispersion, bending and scattering. The attenuation is dependent upon the length of the cable.

  • Absorption — The light intensity gets dimmer as it travels to the end of the fiber because of heating of the ion impurities and it is called absorption of light energy.
  • Dispersion — If the signal goes along the fiber, it does not always adhere to the identical specific path, making it highly distorted.
  • Bending — This reduction occurs because of the bending of the cable, it gives rise to two states. In the first state, the entire cable is bent which limits the additional manifestation of the light or lack of cladding. In the second state, just the cladding is bent slightly, leading to the unnecessary manifestation of the light in different angles.
  • Scattering — The reduction is generated because of the varying microscopic material density or in the presence of varying
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What is Coaxial Cable?

The coaxial cable transmits the signals in the form of electrons, low voltage power. It’s composed of a conductor (usually copper) placed in the center or center that’s surrounded by an insulating sheath. The sheath can also be encased within an outer conductor of a metallic braid, foil or a combination of both. The external metallic wrapping functions as a shield against the sound and completes the circuit because of the next conductor. The outer metallic conductor can also be enclosed in a plastic covering to shields the entire cable. Coaxial cable is a fantastic alternative to an ethernet cable. The coax cables are popularly used in the cable TV to disperse the TV signals.

Coaxial Cable

Losses

The power reduction produced by a coaxial cable is appreciated from the expression attenuation, and it may be affected by the length and frequency of the cable, attenuation can increase as the length increases. Additionally, there are various losses generated for example weight reduction, dielectric loss and radiated reduction.

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  • Resistive reduction — It arises because of the resistance of the conductors, and the flowing current generates heat. The skin effect restricts the real area in which the current flows, but increasing frequency progressively makes it even more apparent. The weight reduction expands as the square-root of this frequency. Multi-stranded conductors may be used to overcome the loss.
  • Dielectric Loss — it’s also another significant loss that arises as a result of an increase in frequency, but it increases linearly unlike weight reduction.
  • Radiated Reduction — The Radiated reduction is lower than resistive and dielectric losses it may generate when a cable has an inferior outer braid. The power radiation leads to interference where the signs can be present at a stage where they’re not required.

Key Differences between Optical Fiber and Coaxial Cable

  1. Optical fiber carries the signals in optical form while coaxial cable carries the signal in the kind of electricity.
  2. Fiber optics cable is constructed from glass fiber and plastic. By comparison, the coax cable is composed of metal wire (aluminum ), metal and plastic mesh braid.
  3. The optical fiber is significantly more efficient than coax cable since it’s higher noise immunity.
  4. Optical cable is more expensive than the coaxial cable.
  5. The optical fiber offers high bandwidth and data prices. On the contrary, the bandwidth and data rates offered by the coax cable are reasonably high but lower than optical cable.
  6. Coaxial cable is easily installed whereas installment of optical cable requires additional effort and attention.
  7. The effect of bending of the cable is negative in case of an optical According to, the coaxial cable is untouched by the bending.
  8. The optical fiber is lightweight and has a small diameter. Conversely, a coaxial cable is thicker and has a large diameter.

Advantages of Optical Fiber

  • Noise resistance — As fiber optic cable uses light rather than electricity, the sound isn’t an issue. External light likely could create some interference, but that’s already blocked from the station by the outer coat.
  • Less attenuation — The transmission distance is remarkably greater than that of some other media that is guided. In optical fiber cable, a sign can run for miles without needing regeneration.
  • Higher bandwidth — Fiber-optic cable may carry increased bandwidth.
  • Speed — It provides higher transmission prices.

Disadvantages of Optical Fiber

  • Cost — Optical fiber is expensive as it has to be manufactured precisely and a laser light source costs a lot.
  • Installation and maintenance — A cracked or rough center of the optical fiber can diffuse the light and stop the signal. All the joints have to be perfectly polished, sealed and aligned light-tight. It uses unsophisticated tools for cutting and crimping, making it more challenging to install and maintain.
  • Fragility — Glass fiber is much more fragile and easily broken than a cable.

Advantages of Coaxial Cable

  • Frequency characteristics — Coaxial cable has a much better frequency characteristic when compared to twisted pair cable.
  • Susceptibility towards interference and crosstalk — It’s less prone to interference and crosstalk due to concentric construction of this cable.
  • Signaling — Coax cable supports both digital and analog signaling.
  • Cost — It is more affordable than optical fiber.

Disadvantages of Coaxial Cable

  • Distance traveled by the signal — A repeater is necessary for each kilometer when the communication devices are put at a longer distance.

Conclusion

The Optical fiber is significantly more efficient compared to coaxial cable in terms of data transmission speed, interference and noise immunity, measurements, bandwidth, losses etc.. However, coaxial cable is more economical, easily installed and available, and bending of the cable doesn’t affect the signalling from the cable.

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