23 Jul 2024


New Power-over-Ethernet spec triples power ratings

In its new US lab, CommScope will test how cables are affected by applications running the new four-pair Power-over-Ethernet standard.

A new version of the IEEE’s Power-over-Ethernet (PoE) standard has added three new classes of operation and tripled the maximum amount of power that can be transmitted via Ethernet cables from 30W to 90W. According to the Ethernet Alliance, the ratification of IEEE 802.3bt – Amendment 2: Power over Ethernet (PoE) over 4 Pairs, “heralds a new era of robust market opportunity for PoE-enabled technologies”.

Responding to market and end-user demand, the IEEE 802.3bt standard offers several new features and capabilities, including support for efficient four-pair power delivery, and channel definitions for 2.5Gbps (gigabit per second), 5Gbps and 10Gbps PoE operations. The new specification also triples the maximum power that power sourcing equipment (PSE) can handle from 30W to 90W, and raises the maximum power level for powered devices (PDs) to 71.3W. In addition, IEEE 802.3bt doubles the number of supported classes from four to eight, addressing Type 3 and 4 devices for PSEs and PDs between 4–90W and 3.84–71.3W respectively.

“The IEEE 802.3bt standard was skilfully crafted to facilitate the swift expansion of an array of PoE use cases,” explains John D’Ambrosia, chairman of the Ethernet Alliance, the global consortium dedicated to advancing Ethernet technologies. “This inherent flexibility will help future-proof networks by enabling them to capitalise on a new generation of advanced PoE technologies.”

Tam Dell’Oro, founder and CEO of the Dell’Oro Group, which specialises in analysing the communications market, predicts that demand for PoE-enabled switch ports will surge following the ratification of the new specification, and forecasts that 850 million ports will ship over the coming five years.

Another analyst, Grand View Research, has predicted that the global PoE market will expand from $445m in 2015 to reach $3.77bn by 2025 as the new four-pair standard empowers more applications and devices to use the technology.

Dell’Oro says that the market growth will be “fuelled by growing adoption of IEEE 802.11ac wireless access points and a diversity of emerging applications encompassing network-attached storage, building automation, security, entertainment, and more… With the increase in its power delivery capacities, combined with its cost-efficiency, flexibility, and scalability, PoE has evolved as a competitive solution for the enterprise and consumers alike.”

The Ethernet Alliance expects the arrival of the new specification to boost its PoE certification programme, which simplifies the process of identifying which PSE and PD products will work together. With the ratification of IEEE 802.3bt, the organisation has started work on the second generation of the programme.

“With the increased number of classes and extended range of use cases of the IEEE 802.3bt standard, it’s imperative to have an effective means for easily identifying which PDs and PSEs can be coupled together, and that’s where the Ethernet Alliance Generation 2 PoE Certification Program will come in,” D’Ambrosia explains. “By providing a quick, effortless approach for visually identifying compatible products, the program helps promote multivendor interoperability and ensures users reap the full benefits of current and future PoE solutions.”

•  The US communications infrastructure specialist CommScope has established an r&d lab in North Carolina where it will test next-generation PoE applications to verify the performance and safety of the structured cabling systems that support them, especially their thermal performance in real-world installations. CommScope says that because the new four-pair PoE standard allows more power to be delivered by PoE switches, more research is needed to verify the impact in cabling of a variety of installation conditions.