Difference between Unshielded Twisted Pair (UTP) and Shielded Twisted Pair (STP) cables.

Unshielded Twisted Pair or UTP are twisted pair cables that are used to transmit both data and voice, as their frequency range is suitable for transmission. UTPs are more cost-effective and are not needed to be grounded.

Shielded Twisted Pair or STP are also a twisted pair cables but are required to be grounded, wants more maintenance, have high data transmission capacity and are costlier than UTP.

Read through this article to find out more about UTP and STP cables and how they are different from each other.

What are Shielded Twisted Pair (STP) Cables?

IBM invented shielded twisted pair (STP) cable for token ring networks, including two independent wires coated in a foil shielding that prevents electromagnetic interference and speeds up data transmission.

STP cables are protected with additional foil or copper knitting jackets to help protect cable signals from interference. STP cables can transmit data at higher prices over longer distances. Electromagnetic interference does not seep out of or into STP cable because of the additional coverage.

Ethernet networks, particularly fast-data-rate Ethernets, frequently use STP cables. The efficiency of the additional covering varies depending on the shielding substance, such as −

  • Frequency
  • Thickness
  • electromagnetic noise field type
  • Discontinuity in the shield
  • Grounding exercises

Unlike UTP cables, specific STP cables feature a thick copper braided cover, making the wire thicker, heavier, and thus far more difficult to install.

Other standard STP cables, also known as foil twisted-pair cables or screened twisted-pair cables, have a minor outer foil barrier. These cables are thinner and less expensive than braided STP cables, but they're also more challenging to install. If the maximum pulling force and minimum bend radius are not adhered to during the installation procedure, these thinner cables may be torn.

Applications and Uses of STP Cables

Shielded Twisted Pair copper telephone wiring is a type of copper telephone wiring utilized in some commercial applications. The shielded twisted pair cabling is most commonly used in frigid temperatures. The extra layer of outer covering makes it perfect for withstanding such temperatures or preserving the inner parts. As a result, it's ideal for research in environments where temperatures drop below zero, rendering traditional wires worthless. In a similar vein, these wires can be employed in heavy industrial applications that generate a lot of heat.

The same rationale that makes these cables suitable for usage in cold weather also applies in this situation. It also qualifies the insulated twisted pairs for high-radiation conditions where people do not have much leeway.

Advantages of STP Cables

Shielded twisted pair cable (STP) has the following advantages −

  • Lowers crosstalk and provides interference protection.

  • It has superior electrical properties to unshielded cables.

  • A modular connector can be used to link it to the rest of the system.

Disadvantages of STP Cables

Shielded twisted pair cable (STP) has the following disadvantages −

  • It is more expensive per foot of wire.

  • STP cable shields must be correctly grounded or behave as an antenna and pick up undesired signals.

  • More costly than UTP.

  • It's challenging to set up and keep up.

  • Much thicker and less flexible in diameter.

  • It has a high rate of attenuation.

  • Despite its thicker and heavier structure, there is no improvement in segment length while utilizing this cable.

Despite these drawbacks, one thing is clear − the protected twisted pair can tolerate various externalities but is vulnerable to internal disturbances. If they are to be used, one must ensure that internal disorders do not interfere with the functioning or purpose. When this is considered, the insulated twisted pair of wires can be as beneficial to us as building blocks were to the primitive man.

What are Unshielded Twisted Pair (UTP) Cables?

Unshielded Twisted Pair (UTP) is an unprotected cable. UTP cable is a 100-ohm copper cable with 2 to 1800 unchanging twisted pairs and an outer jacket.

UTP cables can be used for network connections that are short to medium in length. Some video apps use this cable type as well. UTP Network Cable Categories support a variety of data transfer speeds.

Four twisted pairs are generally found in a single UTP network connection. It's a cost-effective option for LAN and phone connections, with a tiny diameter and simple installation.

UTP wiring comprises two insulated copper wires that have been wrapped around one another and are widely used. There are two conductors in each pair. The pair's one wire has the pair color with a white stripe, while the other has the color white with the pair color stripe.

UTP Cables are terminated with standard connectors in commercial networks. The maximum run length for a UTP cabling system is 100 meters. Fiber-optic lines can provide greater capacity and better interference protection, but these benefits can come at a cost.

Applications of UTP Cables

  • UTP connections are extensively used in LAN networks.

  • Low-speed data, high-speed data, voice, audio, and paging systems, as well as building automation and control systems, can all benefit from UTP.

  • UTP cables can be used in both straight and vertical sub-systems.

Specifications and Categories of UTP Cables

UTP cables were designed with voice applications in mind. Only analog signals, which are exceptionally strong and not easily damaged by electrical noise, are carried through voice UTP cables.

Higher-quality UTP cables were necessary to enable data systems that utilized digital signalling, as UTP cables were used for multiple systems.

Various classifications or grades of UTP cables were developed throughout time as the uses evolved. UTP cables of a higher category are known as data-grade UTP cables, whereas lower category UTP cables are known as voice-grade UTP cables

Difference between UTP and STP

The following table highlights the major differences between UTP and STP −

Key Unshielded Twisted Pair (UTP) Shielded Twisted Pair (STP)
Full form UTP stands for Unshielded Twisted Pair. STP stands for Shielded Twisted Pair.
Grounding Grounding cable in not required. Grounding cable is required.
Data Transmission Rate Data Transmission Rate is slower than STP. Data Transmission Rate is very high.
Cost UTP cables are cheaper. STP cables are expensive.
Maintenance Low maintenance cost in case of UTP. High maintenance cost in case of STP.
Noise Noise is high in UTP. Noise is quite less in STP.
Crosstalk Possibility of crosstalk is very high in UTP. Possibility of crosstalk is quiet low in STP.


UTP cables offer several significant advantages over STP cables. UTP cables are less expensive and easy to maintain. UTP cables are easy to set up because they don't require any extra cable management. It is easier to cram UTP cables into close locations.

On the flip side, UTP cables are more susceptible to interference than most other cable types. Twisting the pairs helps to some extent, but it does not protect the cable from electrical noise. UTP cables can only be used for cable segments up to 100 meters in length. The only drawback that UTP has over STP is when it is employed in an unsuitable environment.

STP products may be preferred over UTP when enhanced protection against crosstalk and interference is required.

Updated on: 04-Aug-2022

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