Fiber optic cables and twisted pair cables are the two main network cables commonly used in data centers. Fiber cables are usually used with optical modules and are suitable for large-capacity long-distance data transmission. Category series network cables are suitable for rack-to-rack connections. This article will describe how the features of the two differ.
Fiber Optic Cable
Optical fiber cable, also known as fiber optic cable, is a kind of cable that provides a stable environment for the transmission of laser signals, and consists of one or more optical fibers used to transmit data. The material of the fiber core is SiO2. Fiber-optic cables transmit data when pulses of light travel through tiny glass tubes. The transmission capacity of optical cables is extremely high, which can reach thousands of times that of cables.
Optical fibers can be divided into single mode fibers (SMF) and multimode fibers (MMF). The transmission of light along the axis of the fiber completely avoids dispersion and waste of light energy. The multimode fiber light will be continuously reflected along the edge wall of the fiber, and there is a lot of dispersion and waste of light energy. Single-mode optical fibers are divided into two categories: OS1/OS2. Now the common single-mode optical cables are OS2 optical cables, and multi-mode optical cables include OM1, OM2, OM3, OM4, and OM5. At present, the most common is OM3/OM4. The advantage of single-mode optical cable is that the transmission distance is extremely long, which can reach thousands of kilometers, while the transmission distance of multi-mode optical fiber is often within 500M.
Twisted Pair Cable
Twisted pair cables are commonly used in data center TOR/EOR architectures and can be found everywhere in everyday life. It twists two copper wires of a single circuit, and a pair of wires forms a circuit that can transmit data. Twisted pair can reduce electromagnetic radiation and crosstalk between adjacent pairs.
There are various types of twisted pair including Cat5, Cat5e, Cat6, Cat6a, Cat7 and the latest Cat8.
According to the shielding type of twisted pair, it can be divided into two major categories: Unshielded Twisted Pair (UTP) and Shielded Twisted Pair (STP). STP copper cables have a foil wrapped cable on the outside of each pair of wires. The four pairs of wires are then wrapped in an overall metal braid or foil. STP cables have better noise immunity than UTP cables.
Fiber Optic Cable vs Twisted Pair Cable: What’s the Difference?
In addition to materials, twisted pair and optical fiber jumpers are very different in transmission capacity, transmission distance, speed, bandwidth and other parameters. The following table will compare the specifications
Speed, Bandwidth & Distance
| Cable Type | Speed | Bandwidth | Distance |
| OS2 | 1/10/25/40/100/200/400G/800Gbps | 4700 MHz | Depends on Attenuation |
| Cat6a | Up to 10 Gbps | 500 MHz | Up to 100m |
Cable Price
In 2022, due to the large-scale application of optical cables, the price of optical fibers is already close to that of copper cables. It’s a very cost-effective option.
| Cable Type | Description | Price* |
| OS2 | 3ft LC to LC duplex 9/125 single mode fiber patch cable | ~ $3-4 |
| Twisted pair cable | 3ft Cat6a 24AWG SFTP Ethernet network patch cable | ~ $8-9 |
*Prices are from some online vendors’ product pages. They may change with time.
Unexpectedly, the price of fiber optic cable is much lower than cat cable.
Application
Fiber optic cables can be used in many environments. In addition to indoor environments, they can also be used in submarines, utility poles, and underground. Some optical fibers can be equipped with metal armor or other reinforcing structures, and its durability can be greatly enhanced. In contrast, network cables are generally only used indoors. Outdoor use of copper cables will encounter many problems, such as corrosion, rat bites, etc. Both are easy to install. Copper cables are heavier and have larger bending radii, so indoor wiring is not flexible. However, it has the characteristics of being able to supply power, so it has many applications in POE/POE+ devices, such as ip cameras\POE transceivers, etc.
Summary
To sum up, there are obvious differences between fiber optic cables and twisted pair cables. With the increase of bandwidth, the demand of optical fiber in the communication industry is increasing day by day. If you have more questions, please contact us.