Shielded Copper Cabling Learning Center

The benefits of standards-based shielded cabling

Today’s category 6A shielded twisted-pair copper cabling provides superior crosstalk performance, higher signal-to-noise margin, external noise immunity, heat dissipation, extended lifecycle and simple installation, ensuring cost-effective and superior support of high-speed 10 Gig and remote powering applications. That is why across the world, cabling manufacturers are seeing shielded cabling gain market share, with adoption growth outpacing UTP.

Why deploy shielded cabling systems?

Increased Headroom, Better Crosstalk Performance and a Longer Lifecycle

Exhibits a Shannon Capacity of 23 Gb/s at 500 MHz, vs just 18 Gb/s for UTP and provides a full 20dB of margin for alien crosstalk vs. the limits, nearly 20dB better than UTP. With superior crosstalk immunity, excellent external noise immunity, higher signal-to-noise margins than category 6A UTP, shielded cabling delivers the performance and headroom needed to deliver reliable 10 Gig performance.

The longer a cabling system lasts, the lower its total cost of ownership. Shielded twisted-pair copper cabling systems provide a longer lifecycle compared to UTP. In fact, TCO models clearly demonstrate that the extensive benefits provided by category 6A F/UTP cabling may be realized for nearly the same cost as category 6A UTP cabling. And, category 6A F/UTP cabling's performance headroom and installation robustness compared to category 6A UTP may lend itself to being capable of supporting the next Ethernet application beyond 10GBASE-T over limited topologies

Heat Dissipation and Higher Temperature Rating for Support of PoE

Thermal graphExcessive temperature rise in the cabling plant can result in an increase in insertion loss and premature aging of jacketing materials. Choosing media with improved heat dissipation performance can minimize the risks associated with excessive temperature. Extensive theoretical and experimental data contributed to the TIA and ISO/IEC Standards committees conclusively demonstrates that UTP systems exhibit approximately twice the temperature rise when pairs are subjected to a DC current than shielded systems do. Metal shields have a higher conductivity to dissipate heat than jacketing materials. As a result, bundling recommendations and insertion loss de-rating for shielded cables supporting remote powering applications, such as PoE Type 1, Type 2, Type 3 and Type 4, are significantly less restrictive than for unshielded cables.

Siemon solid shielded category 6A and 7A cables are also qualified for mechanical reliability in high temperature environments up to 75° C. This higher temperature rating is especially critical for support of the IEEE 802.3bt Type 3 and Type 4 PoE application that exhibit a temperature rise within bundled cable configurations. For cabling infrastructure expected to support power delivery to data terminal equipment, the practice recommended by industry standards is to not install 60° C rated cables in environments above 50° C.  Siemon shielded category 6A and 7A cables may be installed in environments up to the maximum 60° C specified by TIA and ISO/IEC standards and will not experience mechanical degradation caused by heat build-up inside the cable bundle due to PoE remote power delivery.

Immunity to External Noise and Increased Security

Environmental noise is comprised of magnetic and electric fields. Magnetic field coupling occurs only at low frequencies (i.e. 50 Hz or 60 Hz) and its impact can be ignored for all types of balanced cabling. Electric fields, however, can produce disturbing signal voltages on balanced cables. Cable shield protects data transmissions from common electromagnetic interference, allowing error-free performance in "noisy" environments. In models and experiments prove that UTP cables have 100 times more potential to radiate and receive signals (i.e., behave like an antenna) than shielded cables under ideal termination conditions and are 10 times more likely to radiate and receive signals under worst case ungrounded conditions. And the same shielded cable construction that keeps outside signals out, also keeps transmissions in, securing data from unwanted signal radiation.


To learn more, download the white paper, “Government Levels of Security Enhanced with TERA® Cabling System.

Less Restrictive Installation Practices

UTP cabling relies on jacket diameter and pair-pair spacing to meet alien crosstalk requirements. Anything that deforms the jacket - exceeding bend radius, over-cinching tie-wraps exceeding pathway fill recommendations, bundling too many cables - will degrade performance. F/UTP cabling controls crosstalk with an overall foil, giving it more resistance to the negative effects of jacket deformation. Cable shields also eliminate alien crosstalk to the extent that testing is not required.

Today’s shielded cabling systems are also far easier to terminate and deploy than the old shielded systems from decades ago. In fact, Siemon’s Z-MAX 6A Shielded System can be terminated in less than 60 seconds. And Siemon’s Z-MAX 6A and TERA Shielded Outlet design and termination process automatically ground to the patch panel in the TR during installation, without the need to individually provide a ground termination for each outlet. The only additional step required to ground these F/UTP and S/FTP cabling systems is to connect a 6 AWG wire from the ground lug on the patch panel to the telecommunications grounding busbar (TGB).


To learn more, download the white paper, “Grounding for Screened and Shielded Network Cabling.

Recommended by Industry Standards

The key cabling standards recommend 10 Gb/s or better cabling based on the time-tested best-practice of selecting systems that will provide the maximum longevity. This minimizes the disruption and downtime associated with lower-performing cabling and provides lower total cost of ownership for the cabling plant. Category 6A is also recommended by industry standards for the latest 802.11 Wi-Fi standards, and shielded cabling is recommended for heat dissipation and noise immunity. Article 708.14 of the National Electric Code (NFPA 70) also recommends shielded cabling for security, life safety and emergency communications systems. The ANSI/TIA-1179 healthcare standard recommends that whenever possible, designers give serious consideration to the highest-performing media.


To learn more about 802.11 Wi-Fi, read the blog, “What Type of Cabling Do I Need for the Latest 802.11 Wi-Fi?