Page 18 - PEN eBook March 2023
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POWER SUPPLIES Power Supplies
Understanding the environment for standardized PoE is crucial to conceiving, designing and
developing IP phones, security cameras, wireless access points, speakers, LED lighting, biometric
readers, doorbells/entry systems, electricity/gas meters, point-of-sale systems, swipe-card readers,
temperature sensors and a growing range of other products that run over PoE.
One of the most important challenges facing device manufacturers and users is ensuring
interoperability of multi-vendor power sourcing equipment (PSEs) and powered devices (PDs). For
example, merely utilizing commercial PSEs to test PDs may have grown more commonplace in
the rapidly growing market, but it is an ineffective approach for ensuring interoperability. That’s
because it overlooks the design flexibility written into the IEEE 802.3 PoE standards. A variety of
PSE designs and configurations with widely varying tolerances of different PD traits are being made
available, and a given PD’s ability to work with one or a few PSEs does not necessarily project
to reliable interoperability with the hundreds of other specification-compliant PSEs and cabling
networks that are deployed in the world today.
Bringing clarity and assurance to the global PoE market is at the heart of the Ethernet Alliance PoE
Certification Program.
FUELING GLOBAL PoE MARKET GROWTH
Ensuring Three generations of IEEE 802.3 standards undergird the global PoE market environment today:
IEEE 802.3af, defining PDs drawing up to 13 W from Ethernet connections and PSEs
▶
PoE-Powered Devices ▶ IEEE 802.3at, defining PDs drawing up to 25.5 W and PSEs furnishing 30 W
furnishing at least 15.4 W
Will Interoperate as ▶ IEEE 802.3bt, defining PDs drawing up to 71.3 W and PSEs furnishing up to 90 W
Advertised Relying on test plans developed by many of the same individuals who helped write the IEEE 802.3
PoE standards, the Ethernet Alliance PoE Certification Program was introduced in 2017 to improve
PoE end-user experience by minimizing market interoperability issues and confusion. Gen 1 EA
By Peter Johnson, Ethernet Alliance member and vice president of engineering Certified testing is based on IEEE 802.3af and IEEE 802.3at, and Gen 2 testing is based on IEEE
and co-founder of Sifos Technologies, and David Tremblay, chair of the 802.3bt.
Ethernet Alliance PoE Certification Program and system architect at Aruba
Networks, Hewlett Packard Enterprise’s networking division The EA Certified program provides a publicly accessible certified product registry, easily recognizable
trademarked logos and convenient options for third-party testing in authorized labs in either Asia
Rapid growth in the number and types of devices that rely on Power over Ethernet (PoE) is evident or North America, or first-party testing via approved test equipment. For example, using the Sifos
globally. PoE ports, which accounted for 30% of total ports in 2021, are “forecast to comprise nearly Technologies PDA-602B and PDA-604A Powered Device Analyzers and associated software, Gen 1
half of the total campus port shipments by 2026,” according to the Dell’Oro Group’s “Ethernet and Gen 2 certification testing is fully automated, yielding test reports that can then be submitted
Switch – Campus 5-Year July 2022 Forecast Report.” The PoE market through 2030 is “anticipated to the Ethernet Alliance for logo certification.
to flourish at a robust compound annual growth rate of approximately 16.20% to surpass
$3.2 billion,” according to a Market Research Future report released in September 2022. The benefits that the Ethernet Alliance program offers to the global PoE community have been
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