What are the types of cables used in networks?

Fiber optic cable, twisted pair cable, and coaxial cable are the three main types of network cables used in communication systems. Each of them is different and suitable for various applications.

Coaxial Cable

Coaxial cable, or coax cable, is a type of copper cable which has an inner conductor surrounded by foam insulation, symmetrically wrapped by a woven braided metal shield, then covered by in a plastic jacket (as shown in the following image). This unique design allows coaxial cable runs to installed next to metal objects such as gutters without the power losses that occur in other types of transmission lines.

This kind of cable is mainly adopted in feedlines connecting radio transmitters and receivers with their antennas, computer network connections, and distributing cable television signals.

The coaxial cables were not primarily developed for the computer network. Because of its low cost and long durability, coaxial cables were used in computer networking for nearly two decades (the 80s and 90s). They are still used even their use in computer networks has been completely discontinued.

Fiber Optic Cable

Fiber optic cable consists of a core, cladding, buffer, and jacket. The core is made from thin strands of glass or plastic that can carry data over a long distance. The core is wrapped in the cladding; the cladding is wrapped in the buffer, and the buffer is wrapped in the jacket.

Fiber optic cables send digital data at the speed of light. A fiber optic cable can contain a varying number of these glass fibers -- from a few up to a couple hundred, so optical fiber is the core part of optical fiber cable.

Fiber optic cable is completely immune to EMI and RFI. This cable can transmit data over a long distance at the highest speed. It can transmit data up to 40 kilometers at the speed of 100Gbps.

Twisted-pair cables

The twisted-pair cable was primarily developed for computer networks. This cable is also known as Ethernet cable. Almost all modern LAN computer networks use this cable.

The TIA/EIA 568 divides the twisted-pair cable into several categories. The following table lists the most common and popular categories of twisted-pair cable. The easiest way to select a cable is to pick one with the range and performance you need.

We’re skipping categories 1, 2, and 4, as they are not technically recognized as Ethernet standards and have no application today. We’re also skipping 3 and 5 because they are obsolete, slow, and discontinued.

Cat 5e

Cat5e (Cat5 enhanced) is the cheapest, but it is also the slowest. It supports data transmission speeds of one gigabit per second (Gbps), a frequency of 100 MHz, and a maximum length of 328 feet. The crosstalk between the wires in the cable is reduced, thereby reducing the chance of interference and transmission errors. Of course, it will provide capable performance for most applications today, but Cat5e also leaves fewer opportunities for future upgrades.

Cat6

Cat6 is another improvement of the previous version of Cat5e. It consists of four pairs of copper wires and supports Ethernet connections up to 10Gbps. Under normal circumstances, within a range of 100 meters, it supports a maximum transmission speed of up to 1 Gbps. The Cat6 cable supports 37-55 meters (depending on crosstalk) when transmitting at 10Gbps. It can transmit signals with frequencies up to 250MHz, which indicates the frequency at which the signal can pass through the cable. More importantly, it uses RJ-45 standard connectors and is backward compatible with its previous versions, such as Cat5 and Cat5e. Cat6 cables are generally very affordable, and their speed is 10 times that of Cat5e cables. However, their prices are higher than Cat5e cables, and they are also relatively short.

Cat 6a 

Cat6a cable is an enhanced version of the Cat6 Ethernet cable. This enhanced Cat6 cable includes a higher standard bandwidth, starting at 500 MHz and going up to 550 MHz. This standard bandwidth is twice that of Cat6, which carries important consequences. Chief among them is that Cat6A can maintain a data rate of 10 Gbps over distances of up to 100 meters. That’s about twice the difference of Cat6.

If you want to set yourself up for a successful long-term Gigabit Ethernet network, Cat6a (Category 6 Enhanced) is the right choice. Yes, it’s more expensive than Cat5e or Cat6, but as the technology evolves, the hardware you’ll connect to your network will only get more complex, not less. cat6a supports the same 10Gbps transmission speed as Cat6, but up to 328 feet and at 500MHz. of course, there’s less crosstalk compared to Cat6.

Cat6a Ethernet cables also come with a stronger jacket that not only reduces but completely eliminates AXT (extraneous crosstalk) and improves the quality of the SNR (signal-to-noise ratio). Basically, Cat6a cables have reduced crosstalk and are more likely to give you the maximum possible speed of 10Gbps.

Cat 7 and Cat 7a

Cat7 cables stand for Category 7 cables that are used to provide cables for Gigabit Ethernet infrastructure. It provides frequencies up to 600MHz. It is the perfect choice for wiring your smart home. After wiring, you can even check automation ideas. It supports high-speed Ethernet communications up to 10Gbps. These are backward compatible with Cat6, Cat5, and Cat5e. It provides a 100-meter 4 connection channel with shielded wiring. They require twisted pair wires to become a fully shielded system. This system is called shielded twisted pair (SSTP) or shielded foil twisted pair (SFTP) cabling. It eliminates foreign cross-talk and has better noise immunity. It allows users to obtain higher speeds with longer cables.

Cat7a Ethernet cable refers to “Category 7 Enhanced”, or Category F enhanced products. This was introduced by ISO 11801 Edition 2 Amendment 2 (2010) and defines frequencies up to 1000 MHz.

Category 7a cables may have been initially introduced as a future-proof step to meet the expected widespread adoption of the 40 Gbps Ethernet standard. -However, in 2016, a new approval meant that this responsibility was effectively handed over to Cat8 cables designated for 2000 MHz. As a result, cable Cat7a is not officially supported by very many devices as a standalone revision.

Cat 8

Cat8 Ethernet cables have made great leaps in performance and speed. Cat8 Ethernet cable can support frequencies up to 2GHz (or 2000Mhz), which is more than twice that of Cat7.

More importantly, Cat8 Ethernet cable can achieve the speed of Cat8.1 up to 25Gbps and Cat8.2 up to 40Gbps. This is a huge upgrade to the speed of its predecessors–especially it can even support higher data transmission rates within a short distance of 30 meters.

Cat8 Ethernet cable is also designed as shielded wiring to reduce interference. This is achieved through the use of S/FTP, which refers to shielding with foiled twisted pair cables. The working method of this shielding is that the twisted pair is first wrapped in aluminum foil, and then covered by a sturdy 4-pair woven net, which is flexible and highly durable. The braided screen design enables better grounding and usually achieves the highest performance of copper cables. Like all other Ethernet cables, Cat8 uses RJ45 connectors and is backward compatible.

Finally, at its extreme speed, Cat 8 is not really designed for home use. At least not yet. To take full advantage of the speed of Cat 8, you need not only a suitable Cat 8 cable, but also compatible switches, routers, and network cards to support it. So similar to Cat7, it is most suitable for industrial use.