IEEE approves PoE Plus, 802.11n standards

Oct. 1, 2009
The Institute of Electrical and Electronics Engineers (IEEE; in September approved two long-awaited sets of specifications that have the potential to affect each other as well as enterprise end users' deployment of communications systems.

Compiled by Patrick McLaughlin

The Institute of Electrical and Electronics Engineers (IEEE; in September approved two long-awaited sets of specifications that have the potential to affect each other as well as enterprise end users' deployment of communications systems. The standards are commonly known as Power over Ethernet (PoE) Plus and 11n. But now that they are official, here are their official names: IEEE 802.3at Standard for Information Technology – Telecommunications and Information Exchange Between Systems – Local and Metropolitan Area Networks – Specific Requirements Part 3: Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications – Amendment: Data Terminal Equipment (DTE) Power Via the Media Dependent Interface (MDI) Enhancements; and, not rolling off the tongue any more easily, IEEE 802.11 Standard for Information Technology – Telecommunications and Information Exchange Between Systems – Local and Metropolitan Area Networks – Specific Requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 5: Enhancements for Higher Throughput-2009.

The technologies behind both specifications and the development of each has been tracked in Cabling Installation & Maintenance over the past couple years. When the IEEE announced the approval of PoE Plus, 802.3at chair Mike McCormack said, "We have increased available power up to 25 Watts. This will allow Power over Ethernet to address applications such as high-power wireless APs, gimbal mounted cameras, and even some notebooks, as well as newer emerging applications."

Two providers of PoE technology weighed in on the approval immediately, and as expected their comments were positive. In a statement Microsemi ( "praised ratification" of the standard. "We have been a key contributor to the standardization process," said Paul Pickle, general manager of the company's analog mixed signal group, "starting with the call for interest in November 2004, through the creation of the PoE Plus study group, and on throughout the IEEE 802.3at-2009 ratification process."

Phihong (, a member of the 802.3at working group since its inception in 2005, issued a similar statement, with vice president of marketing Keith Hopwood adding, "Even before the .at specification was approved, our customers were requiring much more than 30W of power per port."

Both Microsemi and Phihong offer midspans that deliver power in excess of the 25 Watts that McCormack referenced. In an article that ran in our August issue (see "PoE+: Squeezing the most out of your cabling," August 2009, p. 17), Microsemi analog mixed signal group's director of telecom products Daniel Feldman explained some of the electrical theory behind the then-in-draft standard. "It is possible to achieve approximately 60 watts per port by using all four pairs of a Category 5 Ethernet cable without infringing the IEEE 802.3at draft 4.2," he explained. "With high-power PoE's 600 mA current level, 51 watts can be delivered, compared to 42 watts for 2-pair solutions.

"This same 4-pair configuration can, alternatively, be used to power 2-pair devices with a lower 30 watts of power per port, while dissipating up to half the power and consuming almost 15% less energy than 2-pair solutions."

That comment by Feldman backs up a statement by 802.3at's McCormack about power efficiency. Specifically, McCormack said, "IEEE 802.3at uses the Link Layer Discover Protocol from IEEE Standard 802.1AB, which allows dynamic power allocation and negotiation down to 1/10th of a Watt, and associated technology including Type, Length Values from IEEE 802.3bc which was also recently approved. This will allow equipment manufacturers to manage their power-supply costs and efficiencies at levels not possible with previous standards, and to cut their costs in the process."

The 560-page 802.11n amendment "will enable rollout of significantly more scalable WLANs that deliver 10-fold-greater data rates than previously defined while ensuring coexistence with legacy systems and security implementations," the IEEE stated when announcing the amendment's approval.

Also according to the organization, more than 400 individuals from equipment and silicon suppliers, service providers, systems integrators, consultant organizations, and academic institutions from more than 20 countries participation in the seven-year effort that led to 802.11n's ratification.

"This was an extraordinarily wide-ranging technical challenge that required the sustained effort and concentration of a terrific variety of participants," said Bruce Kraemer, chair of the IEEE Wireless LAN Working Group. "When we started in 2002, many of the technologies addressed in 802.11n were university-research topics and had not been implemented. The performance improvements achieved via IEEE 802.11n stand to transform the WLAN user experience, and ratification of the amendment sets the stage for a new wave of application innovation and creation of new market opportunities."

Cabling Installation & Maintenance has covered the development of 802.11n from time to time, focusing primarily on the implications of such high-speed wireless transmission on a network's cabling system.

Though the proverbial ink is not yet dry on the 802.11n standard, wireless products conforming to it have been on the market for some time. In July the Wi-Fi Alliance ( announced it would not change the baseline requirements of its 802.11n certification program. Rather, it planned to make minor, optional additions to coincide with the standard's finalization. "The updated test program will preserve interoperability with more than 600 Wi-Fi-certified 802.11n Draft 2.0 products released since June 2007," the Alliance stated then.

"Interoperability across draft and final 802.11n-based products is what really matters as this certification program evolves to mirror developments in the market," commented Phil Solis, practice director at ABI Research ( "The Wi-Fi Alliance led the industry in 2007 by introducing its 802.11n Draft 2.0 program, and is striking the right balance now by adding a few features without sacrificing compatibility with previously certified products."

Short runs…

EVERETT, WA—Fluke Networks ( recently closed its acquisition of wireless LAN test firm AirMagnet ( The company did not release the deal's financial terms. AirMagnet provides performance-management and troubleshooting tools including AirMagnet Wi-Fi Analyzer, Survey, Spectrum Analyzer, and Planner, as well as AirMedic. Fluke Networks' president David Coffin said the company expects that the combined solutions will provide end-to-end network visibility that network engineers need, as well as the actionable information required to deploy, secure, manage, analyze, and troubleshoot their networks independent of media type.

MELVILLE, NY—More than 500 people attended the recent ribbon-cutting ceremony for Leviton's ( new world headquarters. The headquarters serves as the high-tech home of the company's global operations across four continents. The four-story office complex serves as a model high-performance building, the company says, equipped with green-building materials and systems including Leviton's own products.

CHICAGO, IL—Anixter ( and Telezygology ( jointly released the TZ Praetorian cabinet locking system, which delivers electronic access control with audit-trail capability for data center cabinets. The companies say the system's unique characteristic is its ability to easily connect to and use existing 8-pin modular-based twisted-pair cabling systems. The TZ Praetorian is a non-proprietary, open-architecture system designed to integrate with twisted-pair cabling systems as well as IP-enabled access-control and video-surveillance systems. The two companies collaborated to develop the system.

IRVINE, CA—Solarflare Communications ( appointed Danny Shamlou senior vice president of engineering. The 10-Gigabit Ethernet silicon provider says the appointment strengthens its position in the market for silicon aimed at server and switch platforms for next-generation networks. Prior to joining Solarflare, Shamlou served as general manager and engineering vice president at Mindspeed and Conexant, respectively.

CHICAGO, IL—Intertek expanded the scope of its fiber-optic components (FOC) certification services. The company's Lexington, KY lab, a Verizon-certified independent test laboratory under the carrier's Fiber Optic Components program, can now provide GR-20-CORE and GR-409-CORE testing. These standards cover optical fiber, optical-fiber cables, and premises fiber-optic cables. Adding the test capabilities allows manufacturers of fiber-optic cables and components to shorten their time-to-market by consolidating testing of their entire fiber-optic and outside-plant product lines, according to Intertek general manager Keith Kuhn.

TUKWILA, WA—The Light Brigade ( offers a two-day technical training course, Fundamentals of Fiber Optics. This entry-level course covers both multimode and singlemode fiber networks and is intended for installation contractors and end users involved in building and maintaining LANs, municipal networks, and private networks. The course includes extensive hands-on exposure to optical-fiber termination, system testing and troubleshooting, and fusion splicing through six hours of hands-on training. The course is eligible for Certified Fiber Optic Technician and Advanced Fiber Optic Technician certifications through the FOA, and is approved for continuing education credits through BICSI. Editor's note: This entry clarifies a "Short runs" item that ran in our August issue.

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