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FREMONT, Calif. (February 8, 2006) — Phihong USA, the global leader in low-cost Power-over-Ethernet solutions, presented its
proposals on achievable limits of 2-pair and 4-pair solutions at the January 12th meeting of the IEEE 802.3at task force, along with several other member companies. Based on these presentations, the task force
concluded that the standard’s objective of providing enough power for multiband access points and controllable security cameras can be met with a 2-pair solution, which is lower in cost and simpler to implement
compared to 4-pair solutions. Designated PoEPlus, the new standard will more than double the wattage available to powered devices.
“The specification is far from finalized but most members believe a source voltage from the PSE of 51-57V with up to 840mA is a
reasonable expectation,” said Keith Hopwood, vice president of marketing for Phihong USA.
“The drop per pair total in a worst case scenario of 100m cable and connectors is 12.5 ohms, which would provide over 30W at the
powered device. The limiting factor is the temperature rise in bundled cabling,” said Hopwood.
The cable working group is testing 196 cables bundled in a conduit and measuring the temperature rise in all the conductors when
current runs through them. The testing does not reflect a safety concern or fire hazard, but the cables will permanently deform above certain temperatures, causing data attenuation.
“At Phihong, we offer both 2-pair and 4-pair solutions, so we know the 2-pair option is feasible,” said Hopwood.
Other resolutions
In addition, at the meeting, a group was formed to define a detailed classification proposal. The new classification will not only
give a much higher resolution of current required by the powered device but will also signal the powered device of the source power capability of the power sourcing equipment. If implemented as a standard,
PoEPlus will allow at least 30W of power and potentially up to 45W.
Phihong has already developed many products that deliver high-power PoE, but most customers would prefer a common industry standard for all devices on the market.
Applications that will benefit from the IEEE 802.3at initiative include wireless multi-radio access points, Pan Tilt Zoom security
cameras, and IP phones with streaming video displays.
“For some interested in implementing PoE, 12.9W maximum of ‘af’ just isn’t enough power,” said Hopwood. “PoEPlus will
allow increased power to many more devices, enhancing their capabilities, such as those used for streaming video, VoIP, IP security applications and broadband wireless access points.”
Other emerging applications, including emergency lighting, security system sensors and even medical monitoring, will greatly benefit
from combining data and centralized backup power.
The IEEE 802.3at working group has formed three adhoc groups to define voltage limits, advanced classification and a MIB (Management
Interface Base). Phihong will be participating in each of these groups in an effort to develop a pragmatic standard and ensure Phihong products comply to the standard as soon as it is released. The next meeting will
be held in Denver in March. For more information about the PoEPlus working group go to http://grouper.ieee.org/groups/802/3/index.html.
About Power-over-Ethernet
Power-over-Ethernet allows both power and data to be carried over a single Ethernet cable, enabling a device to operate entirely from
the power it receives through the data cable. This eliminates the need for additional wall outlets, so phones can be moved around offices without costly and time-consuming rewiring.
About Phihong
Phihong is the leading supplier of power and accessories to personal electronic, Networking and Home Entertainment OEM’s supplying
power, cradles, hands-free headsets, interface cables and virtually any accessory required for the personal electronic device. With global sales for 2006 expected to exceed $450 million, Phihong has engineering and
manufacturing facilities in North and South America, Taiwan and mainland China. For more information contact Ka Yue Kwok, Phihong, 47800 Fremont Blvd., Fremont, CA 94538, or call (510) 445-0100, fax (510) 445-1678,
email usasales@phihongusa.com, or visit http://www.phihong.com.
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