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For Immediate Release
5 August 2008

New Siemon Whitepaper on Temperature Specification for PoE Plus

"IEEE 802.3at PoE Plus Operating Efficiency: How to Keep a Hot Application Running Cool" was developed to help network professionals select cabling capable of supporting PoE Plus with minimized risk of degraded performance due to elevated temperature.

Siemon has published a new technical whitepaper by noted cabling expert Valerie Maguire (Rybinski) entitled "IEEE 802.3at PoE Plus Operating Efficiency: How to Keep a Hot Application Running Cool". This new whitepaper is available for download at:

With the pending PoE Plus Standard nearing completion and attracting global interest, attention has been focused on temperature-related issues inherent to transmitting higher levels of power over twisted-pair cabling. This current-induced temperature elevation increases the risk of degraded physical and electrical performance, which can impact overall network performance and reliability.

Maguire's comprehensive 8 page white paper provides an in-depth analysis on the nature and causes of cabling temperature increases in PoE Plus applications, dispels some commonly held heat dissipation myths and provides actionable guidance on selecting PoE Plus-capable cabling.

Advice is offered on the cabling best suited to support PoE Plus as this excerpt explains:

"Good heat dissipation performance exhibited by the cabling plant is especially critical since no methods exist today for monitoring temperature rise in an installation or mitigating a high-temperature environment. Historically, a comfortable level of performance margin is considered to be 50 per cent headroom to Standards-specified limits (this would be equivalent to 6 dB headroom for a transmission performance parameter). Following these guidelines, the solutions that offer the most desirable levels of heat dissipation headroom in support of the PoE Plus application are category 6A F/UTP and category 7A S/FTP cabling systems."

Conclusions drawn in the paper include the following points:

  • Although safe for humans, the 600mA currents associated with the PoE Plus application generate heat in the installed cabling plant.
  • Excessive temperature rise in the cabling plant cannot be tested or mitigated in the field.
  • Excessive 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 rise.
  • Category 6A F/UTP cabling systems dissipate almost 50 per cent more heat than category 5e cabling.
  • Category 7A S/FTP cabling systems dissipate at least 60 per cent more heat than category 5e cabling.

To download an electronic copy of Siemon's "IEEE 802.3at PoE Plus Operating Efficiency: How to Keep a Hot Application Running Cool", including complete heat dissipation performance data for category 5e UTP, category 6 UTP, category 6A UTP, category 6A F/UTP, and category 7/7A S/FTP cabling, visit:


About Siemon
Established in 1903, Siemon is an industry leader specialising in the design and manufacture of high quality, high performance low voltage infrastructure solutions and services for data centres, LANs and intelligent buildings. Headquartered in Connecticut, USA, with global sales, technical and logistics expertise spanning 100 countries, Siemon offers a comprehensive suite of copper and optical fibre cabling systems, cabinets, racks, cable management, data centre power and cooling systems and intelligent infrastructure management solutions.

With more than 400 patents specific to structured cabling, Siemon Labs invests heavily in R&D and the development of industry standards, underlining the company’s long-standing commitment to its customers and the industry. Siemon Interconnect Solutions (SIS) is a Siemon business unit comprised of a team of dedicated technical sales professionals supported by Siemon Labs, mechanical, electrical and signal integrity engineers committed to solving industry and customer driven interconnect challenges. Siemon provides custom network infrastructure solutions to OEMs, leading manufacturers, value-added resellers and system integrators.
For further information or supporting picture please contact:
CLEAR Communications
Susann Bladwell, PR Consultant
M: +49 (0)176 7863 4709

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