Power over Ethernet: Latest Developments

Masood_Shariff_headshot Masood Shariff October 6, 2016

PoE-imageThis is the sixth post in a new blog series about intelligent buildings, based on content from the CommScope Connected and Efficient Buildings e-book.

The popularity and widespread adoption of Power over Ethernet (PoE) continues to grow. The range of supported power levels, the variety of powered devices and the commercial advantages of using communications cabling for both data transmission and power delivery are well recognized. A conservative estimate puts the number of PoE ports installed globally at over 100 million. To be successful in deploying PoE in your building environments, there are a few recent developments you need to be aware of.

First, PoE standards are progressing to include higher power levels, which means greater temperatures and cable bundling – for instance, IEEE 802.3BT specifies up to 100W. These changes have triggered a review of cabling design and recommended installation practices. Best practices now include routing cables in well ventilated pathways, optimizing routing to minimize distances, and limiting cable bundle sizes to improve heat dissipation. The impact is that cables and cords in telecommunications rooms may not look as well-combed and dressed as in the past. Smaller, looser cable bundles are better for PoE.

Additionally, record keeping of cables carrying PoE is being enhanced to include bundle identifiers so facility managers and network managers can keep track of the cables to avoid overloading larger bundles with too much power. For example, facility managers may choose to deploy high power PoE circuits in only half the cables within bundles containing more than 24 cables. The industry has been successful in managing PoE installations with over 100 million nodes installed without a single reported case of loss to life or property. CommScope is committed to continue this perfect record as the market adopts higher power levels of PoE.

Finally, there is some confusion about PoE with the upcoming publication of the 2017 revision of the U.S. National Electric Code (NEC). Several issues and concerns regarding the PoE articles in the NEC have been noted. In response, the NEC Standards Council has directed the NEC correlating committee to form a multi-discipline task group to develop resolutions with the qualification that “such a task group should specifically include representation of those with knowledge in telecommunications and Ethernet communications.” Look for more developments here as we collectively work on this issue.

For a concise overview of PoE implementation recommendations, check out best practice #5 in the Connected & Efficient Buildings e-book. If you have any questions, leave me a comment.

About the Author


Masood Shariff

Masood is an Engineer Senior Principal in the systems engineering group of CommScope. Masood represents CommScope in the ISO WG3 committee, TIA TR42 Premises Cabling Standards, including the TIA-568 series, TIA-569-C, TIA-570-B, TIA-606-B, TIA-758, TIA-862, TIA-942-A and related standards working groups. Masood served as chair of TIA TR42.7 for many years and was responsible for copper cabling systems specifications including category 5e, category 6, category 6A, and TSB-162 on WLAN cabling. Masood is currently the chair of the committee for the TIA network security project and the TIA-162 revision project. Masood has a Bachelor of Technology degree from IIT India and a Master of Science degree in Computer Science from the University of Delaware.