Deshielded vs Shielded Ethernet Cable: Which Should I Use?

As we all know, the advantages and disadvantages of shielded and unshielded twisted-pair cable are under debate for a long time. Advocates of STP cable, which includes screened twisted-pair and foil twisted-pair cables, claim that it is superior to UTP cable. Shielded vs deshielded twisted-pair cable, which is the winner? This post will give you the answer.

What is Unshielded Twisted-Pair Cable?

Unshielded twisted pair (UTP) cables are made up of 8 internal wires and are the correct solution for most applications. UTP do not rely on physical shielding to block interference and it relies instead on balancing and filtering techniques using media filters, baluns or both. Unshielded means no additional shielding like meshes or aluminum foil are used. Because of this, unshielded Ethernet cables, also called unshielded twisted pair (UTP) cable are lighter and cheaper. These Ethernet cables are designed to cancel EMI with the way the pairs are twisted inside the cables. Compared with the shielded cables, unshielded cables provide much less protection. These cables performances are often degraded when EMI is present.

What is Shielded Twisted-Pair Cable?

Shielded cables (STP) are used for increased protection from interference and crosstalk, they are typically used in electrically noisy environments. A shielded cable or shield twisted pair (STP) cable has an outside layer or “shield” of conductive material around the internal conductors, which needs to be grounded to cancel the effect of electromagnetic interference (EMI). The conductive shield can reflect or conduct external interference away without affecting the signals of the internal conductor. Therefore, shielded Ethernet cables are usually used to protect signals from EMI over the length of the cable run, so as to result in faster transmission speeds and fewer data errors.

Shielded network cables are usually used when running cables near any equipment or other cable that might cause interference with your signal. Common sources of interference are radio towers, high-powered electrical conduit, or any other device emitting electro-magnetic or radio frequency signals.

This is a figure of Cat6 shielded and unshielded cable.

Shielded vs Unshielded Ethernet Cable: Difference

Different Applications

Since UTP cable is lightweight, thin and flexible, as well as versatile, reliable and inexpensive, millions of nodes have been, and continue to be, wired with this cabling medium. This is especially true for high-data-rate applications. For best performance, this UTP cable should be used as part of a well-engineered structured cabling system.

If STP cable is combined with improperly shielded connectors, connecting hardware or outlets, or if the foil shield itself is damaged, overall signal quality will be degraded. This, in turn, can result in degraded emission and immunity performance. Therefore, for a shielded cabling system to totally reduce interference, every component within that system must be fully and seamlessly shielded, as well as properly installed and maintained.

Different Grounding Methods

If STP cable is combined with improperly shielded connectors, connecting hardware or outlets, or if the foil shield itself is damaged, overall signal quality will be degraded. This, in turn, can result in degraded emission and immunity performance. Therefore, for a shielded cabling system to totally reduce interference, every component within that system must be fully and seamlessly shielded, as well as properly installed and maintained.

The length of the ground conductor itself can also cause problems. If it is too long, it no longer acts as a ground. Therefore, because specific grounding requirements depend on the application, a general grounding policy that ensures the best results for an STP cabling system is not possible.

UTP cabling doesn’t have this problem. While an STP cabling system is dependent on such factors as physical continuity of the cable shield or installation with adequately shielded and grounded components, a UTP cabling system inherently has fewer potential trouble spots and is much easier to install.

How to Splice a Cat5 Cable?

Step 1: Measure the existing cable length and subtract it from the connection distance to determine how much much splice cable to cut.

Step 2: Measure and cut a length of Cat5 cable to a length slightly greater than your splicing measurement and then remove about a half-inch of the cable jacket on either end.

Step 3: Cut the terminated cable (RJ45 jacks on either end) in half and remove about a half-inch of the cable jacket on either side of the cut.

Step 4: Separate the four twisted pairs (eight wires, four pairs in white/green, white/orange, white/blue, white/brown) at the cut ends of each cable.

Step 5: Use the wire stripper or a razor utility knife to remove a quarter-inch of the wire shielding for all of the cables. Take care to keep the wire pairings intact.

Step 6: Twist each wire at both ends of the splice cable to the corresponding wire in the two cut cables (blue to blue, green to green and so on) and wrap each exposed wire connection with a piece of electrical tape.

Step 7: Wrap electrical tape around the Cat5 cable at the splice points to finish the splice.

Unshielded vs Shielded: Which Should I Choose?

STP and UTP cable differ in design and manufacture. But their purpose should be the same — to provide reliable connectivity of electronic equipment. In theory, both types of cable should do this equally well.

As for shielded vs unshielded Ethernet cable, the best choice should largely depend on where you plan to install the cables. As mentioned above, STP and UTP cables are widely used in different fields due to EMI interference requirement. Airports, medical centres and factories often benefit from STP cabling, because these places need to process numerous machines that produce considerable amounts of interference. On the other hand, for home and office use, it’s wise to choose UTP cables.

Besides, the budget is another factor which may determine the final decision. It’s believed that STP cost much more than UTP since it can provide better protection from EMI. It’s true, but the gap is narrow. For instance, Cat6 Ethernet cable at FS, the Cat6 UTP of 10ft length costs 2.6 dollars while Cat6 shield cable with the same length needs 3.6 dollars, there is only a very small gap, which may be significant for large scale installations, but not for small networks.

Therefore, as for shielded vs unshielded Ethernet cable, it should be determined by the intended application. If you’re still not sure what type of cabling you need, please contact us via sales@lightoptics.co.uk for expert advice.