The Difference between Twisted Pair, Coaxial and Fiber Optic Cables

Most of us know the general distinction between ADSL, COAX and Fiber internet, but the cabling behind these connections may be more of a mystery. The three most common types of communication cables are Twisted Pair, Coaxial, Fiber Optic.

Understanding the differences between the three will shed light on how data travels through each cable, which ultimately affects your connection and things like speed, latency, security, cost, etc. Here is a general breakdown of the three different types of cable systems and what they are capable of:

Twisted Pair Cables:

Twisted_Pair_Cables

Twisted pair cables are quite literally a pair of insulated wires that are twisted together to help reduce noise from outside sources. While this does help some, these cables are still very susceptible to outside noise. Twisted pair cables are the most cost-effective option of the three but that also brings about lower bandwidth and high attenuation. There are two types of twisted pair cables:

Unshielded twisted pair (UTP)
  • ‘Unshielded’ meaning it does not rely on physical shielding to block interference
  • Most commonly used cable of the two, often utilized for both residential and business use
  • There are several UTP categories, which increase in bandwidth as you move up the scale, for example:
    • CAT1 = up to 1Mbps | CAT2 = up to 4 Mbps | CAT5e = up to 1Gbps
Shielded twisted pair (STP)
  • ‘Shielded’ with a foil jacket to cancel any external interference
  • Commonly used for large-scale enterprises for high-end applications as well as exterior cabling that may be exposed to environmental elements.

Coaxial Cables:

Coax_CableCoaxial cables are high-frequency transmission cables made up of a single solid-copper core. Data is transferred electrically over the inner conductor and has 80X more transmission capacity than twisted pair cables.

This type of cable is commonly used to deliver TV signals (its higher bandwidth makes it more suitable for video applications) and to connect computers in a network. Along with stable transmission of data, coaxial cables also have anti-jamming capabilities and can effectively protect signals from being interfered. The cost is slightly higher than twisted pair but still considered more economical than fiber. There are also two types of coaxial cables:

75 Ohm
  • Most commonly used to transmit video signals
  • Often connects 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_CablesFiber is the newest form of  transmission cable technology. Instead of transferring data over copper wires, these cables contain optical fibers that transmit data via light, rather than pulses of electricity. Each optical fiber is individually coated with plastic layers and contained in a protective tube, making it extremely resistant to external interference. The result is a very reliable and super fast connection that has 26,000X more transmission capacity than twisted-pair cables, but that also comes with a much higher cost. Again, there are two types of fiber cables: 

Singlemode
  • 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
  • Commonly used in telecom, CATV networks, and Universities.
Multimode
  • Has a larger core diameter that lets multiple modes of light propagate
  • The amount of light reflections increase as they travel through the core, which allows more data to pass through
  • Because of its high dispersion, multimode cables have lower bandwidth, higher attenuation and reduced signal quality further it travels
  • Most commonly used for communication over short distances such as LAN, security systems, and general fiber networks.

Bottom Line

Thinking back to grade school and the Goldilocks and the Three Bears analogy, all three types of cable offer something different. One might be too hot, the other too cold, and hopefully after learning about the differences, you’re able to find the type of system that’s just right for your networking needs.

Learn more about the different ADSL, COAX, and Fiber internet services as a whole to further determine which is best for your organization.