Cat6 Cable: Shielded vs. Unshielded

June 16, 2016 at 8:00 AM


When you need speed, Category 6 (Cat6) Ethernet cable is up to the task. Designed to provide Ethernet transmission speeds up to 1 Gbps, Cat6 is made to perform.


But how do you know whether to use shielded or unshielded Cat6 cable? We’ll help you answer that question and ensure that your network will perform optimally.


Deciding to use unshielded twisted pair (UTP) cable or shielded twisted pair (STP) cable is largely based on your application. The electrical environment surrounding your installation area is the most significant factor to consider. In some cases, cables experience slower transmission speeds and more data transmission errors when they are close to machines, power cables or other electronics that produce high electromagnetic or radio frequency interference (EMI/RFI).


By design, unshielded Cat6 cable provides some resistance to EMI/RFI due to the twisting of the wire pairs. Additionally, running a UTP cable at a 90-degree angle in relation to the source of the interference provides additional protection and minimizes exposure.  With its built-in protection (twisted pairs) and this additional safeguard, UTP Cat6 cabling can provide some protection from EMI/RFI.


If your application requires more protection from electromagnetic interference, shielded Cat6  may be the way to go. Shielding will protect your data from electromagnetic and radio interference, resulting in faster transmission speeds and fewer data errors.  Shielded cable is also better than unshielded cable at protecting from alien crosstalk (AXT).


When using shielded cable, the shield itself must have a drain to keep EMI/RFI from building-up and degrading the signal inside the cable. Draining is usually done at the connection site with a shielded coupler or jack connected to the ground.  It is also important to keep in mind that shielded cable is heavier than unshielded cable and, over time, may cause collapses and structural damage when running multiple cables.


Having a good understanding of your installation site will ultimately be the deciding factor when comparing shielded versus unshielded Cat6 Ethernet cable. In many cases, UTP comes out victorious over STP, except in areas of high EMI/RFI interference. Unless you’re running cable close to strong power lines, motors, magnets or radio antennas, it is likely that STP won’t improve your signal.  


Cat 6 Shielded vs. Unshielded

June 5, 2013 at 10:00 AM

Category 6 cable with drain wire

Category 6 or Cat6 Ethernet cable is designed to provide up to 1 Gbps Ethernet transmission, and is required for 1000 Base-T style networks. However, the choice to use unshielded twisted pairs (UTP) or shielded (or screened) twisted pairs (STP or ScTP) depends on the location of the installation.


Typically, the shield is only required in cases where the cable is run through an area of high electro-magnetic interference or radio frequency interference (EMI/RFI), such as output by strong power lines, motors, magnets, and radio antennas. Outside of these situations, the shield does not help provide a faster or clearer signal, and can add more problems than it solves.


Pros and cons 


Without a shield, Cat 6 UTP cable is already resistant to minor and typical forms of EMI/RFI, such as having a fluorescent light or small motor nearby. In these cases, you should always run the cable at a 90° angle to the source of the interference in order to minimize exposure. Otherwise UTP is cheaper, lighter, and just as effective as STP.


If you need STP cable, you have to remember that the shield itself must drain, otherwise EMI/RFI can build up on it and degrade the signal inside. Drainage is typically done at the connection site by using a shielded coupler or jack that is connected to ground.


Also note that the weight of shielded cable, while not very heavy, can be significant if you are running multiple cables in an area. In some cases, heavy cabling run above a ceiling or behind a wall has caused collapses and structural damage over time.


Quick note: Visit L-com's Ethernet Product Center for a huge selection of common and hard-to-find Ethernet cabling solutions, including shielded, harsh-environment, special jacketed and more.
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