In fact, for most people, the requirements for home networks are very simple, that is, fast speed and stability, so when buying network cables, they think that shielded network cables are much better than unshielded network cables.
So, what is the difference between shielded and unshielded network cables, and how do you choose?
The difference between shielded and unshielded
The shielded network cable has aluminum foil or braided mesh inside to reduce radiation and ensure the system can maintain good transmission performance in an electromagnetic interference environment.
The non-shielded network cable has only 4 pairs of wires of different colors twisted together in the insulated plastic sheath, without a shielding jacket, and a small diameter, which can save space.
The structure of the shielded network cable determines its use. Shielding is to reduce the impact of external electromagnetic interference on data transmission. It is often used in computer rooms with complex electromagnetic environments and strong interference.
The interference environment will cause the network cable transmission signal to be intermittent or even interrupted, and the signal cannot be transmitted normally. The use of shielded network cables can resist interference well, maintain normal transmission, and have good confidentiality performance. The shielding structure of shielded wiring has an inherent advantage in reducing mutual interference between cables. It can not only shield external electromagnetic signals but also block the electromagnetic leakage of the cable itself. It will not emit interference signals to affect the work of other cables and can prevent information from being eavesdropped.
According to the different shielding methods, shielded twisted pair cables are divided into two categories, namely STP (Shielded Twisted-Pair) and FTP (Foil Twisted-Pair).
According to Appendix E of ISO/IEC 11801:2002, the naming rules for different types of twisted pair cables are summarized as follows:
X/YTP
The slash mark / before the total shielding layer, the slash mark / after the individual shielding layers of each pair of wires, and S refers to a wire mesh braided shield; F refers to one or two layers of aluminum foil shielding; SF refers to a wire mesh braided and aluminum foil shielding; U refers to no shielding layer. The following are several common shielding types:
F/UTP
Aluminum foil total shielded twisted pair (F/UTP) is the most traditional shielded twisted pair, mainly used to isolate the 8-core twisted pair from the external electromagnetic field, and has no effect on electromagnetic interference between pairs.
The F/UTP twisted pair is wrapped with a layer of aluminum foil on the outer layer of the 8-core twisted pair. That is, there is a layer of aluminum foil outside the 8 core wires and inside the sheath, and a grounding wire is laid on the conductive surface of the aluminum foil. It is mainly used in Category 5e and Category 6 products.
SF/UTP
The total shielding layer of the SF/UTP shielded twisted pair is aluminum foil + braided mesh, which is a kind of double-layer shielded twisted pair. It does not need a grounding wire as a drain wire. The copper wire mesh has good toughness and is not easy to break so that it can be used as a drain wire for the aluminum foil layer. If the aluminum foil layer breaks, the wire mesh will continue to connect the aluminum foil layer.
SF/UTP twisted pair does not have its own shielding layer on the four twisted pairs. Therefore, it is a shielded twisted pair with only a total shielding layer.
S/FTP
S/FTP shielded twisted pair is a double-layer shielded twisted pair with a wire mesh braided overall shielding layer and wire pair aluminum foil shielding. It is considered to be the best shielding structure for twisted pair cables. It is usually used in Cat 7 or Cat 7A shielded twisted pair cable products and can also be used for Cat 6A shielded twisted pair cables.
S/FTP shielded twisted pair cables usually do not have a skeleton for wire pair isolation in their structure because of the addition of a wire mesh braided layer. The overall cable outer diameter is thicker and harder than ordinary F/UTP cables, and the thickness varies depending on the density of the braided mesh.
Shielded and unshielded network cables can be selected according to different usage environments.
Shielded twisted pair cables are mainly used in environments with strong interference and high bandwidth, such as smart buildings, semi-industrial environments, and industrial environments, and when supporting 2.5G/5G, 10GBASE-T, and other applications, shielded wiring should be used in the horizontal subsystem of the data center and in more complex environments such as confidential information transmission.
Shielding only works when the entire cable has a shielding device and both ends are properly grounded. Therefore, the entire system must be shielded devices, including cables, sockets, crystal heads, and patch panels, and the building needs to have a good grounding system.
Unshielded twisted pair cables are flexible in networking and easy to install. Twisted pair cables themselves are also a good anti-interference structure. They can be used in ordinary daily network environments where there will not be strong interference. If the interference is large, metal bridges and pipes are required as shielding layers for wiring.
The Cat 6 wiring system has reached the performance limit of unshielded twisted pair cables. Cat6e, Cat7, and Cat8 are all twisted pair cables that must be shielded.
Considering the application needs of the future network, in theory, priority should be given to installing the most advanced wiring products because the cost of updating and replacing cables after installation is relatively high. Basically, a wiring system should be used for at least 10 years as a standard. Future network equipment will inevitably require high-performance, stable transmission cables to provide high-speed transmission requirements. In particular, if it is impossible to determine whether the network environment is complex and hidden dangers will affect the network connection experience, it is recommended to directly choose Cat 6 double-shielded or Cat 6a or above network cables.
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