Cable shielding is a type of barrier designed to protect the cable from external disruptions such as electrical interference (EMI), as well as prevents cable signals from interfering with their surrounding cables and equipment.
Shielding is becoming more common, even though not all environments require them. At first, shielded cables were used in spaces with high concentration of electrical equipment and/or secure communications applications. One example for such a space is factory floors. Nowadays shielded cables are commonly used in many spaces such as government, education and healthcare buildings.
Many acronyms describe shielded cables. While many of them are used interchangeably, they each have a unique meaning and properties. Let’s take a look at some of these acronyms.
Cable Shielding Types
Overall foil shield (F) with unshielded twisted pairs (UTP). This cable is very similar to the common UTP cable. the difference between them is the addition of foil underneath the main cable jacket. It is also called FTP. F/UTP cables are common in 10GBaseT applications.
Overall braid shield/screen (S) with unshielded twisted pairs (UTP). While it is occasionally referred to as an STP cable, the two are do NOT provide the same shielding. To identify between them check for an overall barrier and/or individual pairs’ shielding.
This cable shielding type includes both an overall braid shield (S) and foil shield (F) with unshielded twisted pairs (UTP). This cable is also occasionally referred to as an STP cable. Cables with an overall braided screen are very effective at protecting EMI from entering or exiting the cable.
Overall braid shield (S) with foil shield twisted pairs (FTP). The shield under the jacket is a braid, and each individual pair is wrapped with its own foil barrier. The purpose of the additional foil on individual pairs is to limit the amount of crosstalk between the pairs.
Overall foil shield (F) with foil screened twisted pairs (FTP). These shielded cables are commonly used in 10GBaseT applications (similarly to F/UTP cables).
No overall shielding or braid (U) with foil screened twisted pairs (FTP). This type of shielded cable is also frequently used in 10GBaseT applications.