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The shielded wiring system originated in Europe; it consists of a regular unshielded wiring system to which a metal shielding layer is added. The reflection, absorption, and skin effect of the metal shielding layer are utilized to prevent electromagnetic interference and electromagnetic radiation. By combining the balanced principle of twisted pairs with the shielding effect of the shielding layer, this system exhibits excellent electromagnetic compatibility (EMC) properties. We can see that across Europe, the majority of end-users choose shielded cabling systems. Currently, shielded wiring systems are becoming increasingly recognized by more users, and their excellent performance in terms of electromagnetic compatibility is also gaining recognition from an ever-growing number of people. Therefore, shielded wiring products available on the market are no longer limited to European products; an increasing number of manufacturers are offering such products. In the newly released North American wiring standard TIA/EIA-568-B, both shielded and unshielded cables are recommended as media for horizontal cabling, thus ending the history of North America without shielded systems. Common shielding problems and solutions Question: What is EMC? Answer: EMC stands for electromagnetic compatibility, which refers to the ability of electronic devices or network systems to resist electromagnetic interference, while at the same time not generating excessive electromagnetic radiation. In other words, such devices or network systems are required to be able to function properly in harsh electromagnetic environments, while at the same time not emitting excessive electromagnetic waves that could interfere with the proper operation of other devices and networks in the vicinity. Question: UTP cables are an ideal balanced transmission system, so why are FTP cables still used? Answer: UTP cables achieve EMC performance through the twisting of their conductors, which means that EMI is first captured by the UTP cable and then neutralized. However, as the frequency increases, the EMC performance of UTP will decline. Measurements have shown that twisting the cables only enables EMC performance up to 30 MHz; it is ineffective against higher levels of electromagnetic interference. To date, the operating frequencies of most practical network applications are below 30 MHz. Moreover, an ideal balanced transmission system does not exist. The balanced performance of UTP cables depends not only on the quality of the components themselves (such as the twisted pairs), but is also affected by the surrounding environment. This is because metals surrounding the UTP, hidden \"grounds,\" pulling forces during installation, bending, and other such factors can all disrupt its balanced characteristics, thereby reducing its EMC performance. In fact, when installing cables, we usually pass them through metal conduits, plastic conduits, or other types of protection systems with different grounding impedances. Therefore, to achieve stable and consistent performance with respect to the ground, there is only one solution: add an additional layer of aluminum foil around all the core wires for grounding. Aluminum foil provides protection for the fragile twisted pair core, while also creating a balanced environment for UTP cables. This means that the shielding solution based on FTP cables is environment-independent, that is, it is not affected by the environment. FTP combines the balanced characteristics and ease of installation of UTP with the shielding effect of STP, representing a perfect integration of balanced and shielded principles. Question: What is the shielding principle of FTP cables? Answer: Unlike the balanced cancellation principle of twisted pairs, FTP cables have one or two layers of aluminum foil added around the four pairs of twisted wires. By utilizing the principles of metal’s reflection, absorption of electromagnetic waves, and the skin effect (the skin effect refers to the tendency for current to distribute along the surface of a conductor as frequency increases; the higher the frequency, the smaller the skin depth, meaning that higher frequencies result in weaker penetration of electromagnetic waves), such cables effectively prevent external electromagnetic interference from entering the cable, while also preventing internal signals from leaking out and interfering with the operation of other devices. Experiments show that electromagnetic waves with a frequency exceeding 5 MHz can only pass through 38 μm thick aluminum foil. If the thickness of the shielding layer is increased to over 38μm, for example, in Nexon’s FTP cables which use two layers of 25μm thick aluminum foil shielding, this ensures that the frequencies of electromagnetic interference that can penetrate the shielding layer and reach the inside of the cable are mainly below 5MHz. For low-frequency interference below 5MHz, the principle of twisted pairs can be applied to effectively counter it. Question: How do we measure the performance difference between shielded and unshielded systems? Answer: The advantage of the shielding system in FTP cables is that it provides better EMC performance compared to UTP cables, as it relies on isolating the system from the external electromagnetic environment. This is because the electromagnetic environment present in the outside world can affect the data transmission of the entire wiring system. To date, there are no performance metrics or testing methods to express or compare EMC performance. Fortunately, the European Committee for Standardization CENELEC has already begun this work (with Nexans’ structured cabling systems involved), and coupling attenuation has been defined as an indicator for measuring EMC performance. This indicator is also included in the second version of the international wiring standard ISO/IEC11801. Nexon shielded wiring solutions Nexon is the inventor of the FTP series of cables and a leader in shielding technology. All of its shielding product lines have undergone testing and certification by the Danish independent electronics laboratory DELTA, the American insurance testing laboratory UL, and the American ETL testing organization. The specifications of the series of cabling products far exceed those specified by the ISO/IEC 11801, EIA/TIA568B, and EN50173 standards. The Nexon F2TP cable features a unique double-layer longitudinally wrapped aluminum foil shielding structure available nowhere else in the world today. Two layers of 25um thick aluminum foil are wrapped longitudinally around the outside of the UTP cable. This double-layer shielding structure prevents tiny gaps from forming in the shielding layer when the cable is bent or exposed to heat, reduces transfer impedance, improves shielding effectiveness, and also makes grounding – including shielding grounding and protective grounding – easier and more reliable. This high-performance shielded cable is also very easy to install, with an outer diameter of only 6.35 millimeters. For electromagnetic waves above 10 MHz, the reflection of the shielding layer, as well as the mechanisms of absorption and skin effect, are used to counteract electromagnetic interference and radiation; the higher the frequency, the more effective the shielding layer becomes. For low frequencies (