The Difference between Twisted Pair, Coaxial and Fiber Optic Cables

December 11, 2017

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Twisted Pair, Coaxial and Fiber Optic cables are the three most common types of communication cables currently used in modern networks.

The types of cables used to connect your network will affect key elements of your connectivity including the speed of data transfer, latency and overall security.

Below, we have broken down these main cable types to explain the differences and capabilities:

Twisted Pair Cables

As the name suggests, twisted pair cables consist of a set of two insulated wires which are twisted together. The design helps to reduce noise from outside sources (noise is unwanted electrical or electromagnetic energy that degrades the quality of signals and data), but is not always very effective.

Although twisted pair cables are highly effective, they can suffer from lower bandwidth and high attenuation.

There are two types of twisted pair cables; shielded or unshielded.

Shielded Twisted Pair (STP)

This type of twisted pair cable is covered by a foil jacket which cancels any external interference. It is more often used for exterior cabling due to its durability which allows for it to be exposed to the elements.

Unshielded Twisted Pair (UTP)

As opposed to the shielded twisted pair cable, the unshielded cable doesn’t rely on protection to block interference. It is the most commonly used type of twisted pair cable, used in both residential and business applications. Different grades of UTP cable are available depending on the required bandwidth, for example a CAT1 cable offers up to 1Mbps, whereas a CAT5e cable offers up to 1Gbps.

Coaxial Cables

Coaxial cables are high-frequency transmission cables which comprise of a single solid-copper core which transfers the data electrically. They have eighty times more transmission capacity than twisted pair cables and so they are often used for TV signalling as the higher bandwidth makes it more suitable for video applications.

Although the cost of coaxial cables is higher than twisted pair cables, they benefit from more stable transmission of data and protection from interference and are more economical than fiber.

There are also two types of coaxial cables:

75 Ohm

• Often used to transmit video signals
• Used to connect video signals between different components like DVDs, VCRs, or receivers commonly known as A/V cables

50 Ohm

• Primarily utilized to transmit a data signal in a 2-way communication system
• Most commonly used for computer ethernet backbones, AM/FM radio receivers, GPS antenna, police scanners, and cell phone systems

Fiber Optic Cables

Fiber is the most modern type of transmission cabling technology. It uses optical fibers to transmit data via light signals instead of using the slower form of pulses of electricity. The protection used in optical fibers means it blocks external interference very effectively.

Fiber offers a connection that has 26,000 times more transmission capacity than twisted pair cables, however it foes come at a much higher cost.

There are also two types of fiber cables available, single and multi-mode.

Single mode

• Has a small core and only allows one mode of light to propagate at a time
• Because of this, the number of light reflections decrease as they pass through the core
• The result is low attenuation and data that is able to travel further and faster

Multimode

• Multimode fiber is the most commonly used for comms over shorter distances (such as LAN and general fiber networks).
• It has a larger core diameter to allow multiple modes of light to propagate
• Due to higher dispersion rates, multimode fiber cables have lower bandwidth and higher attenuation
• Signal quality reduces the further it travels