Try our NEW Online Store with a better user experience!

Reducing the cost of extending Power over Ethernet

 From the May, 2012 Issue of Cabling Installation & Maintenance Magazine, By Sani Ronen and Daniel Feldman, Microsemi Corp. Power over Ethernet (PoE) continues to draw interest from network cabling system professionals, enabling them to deliver both power and data over the existing Ethernet cabling in a unified infrastructure that is easier to expand, upgrade and maintain. The latest PoE advancements offer new opportunities to further reduce power consumption and associated energy costs, while extending the distance that powered devices (PDs) can be placed from the data and power source. The choice of PoE extension technology can have a significant impact on cost and powering capabilities. Importance of PoE reach extension  Ethernet standards limit data delivery to 100 meters (m) from the switch (typically located in the communication room) and any device connected to it, such as an Internet Protocol (IP) phone or IP camera. Data integrity cannot be guaranteed beyond this distance. If, for example, a company wishes to add a camera to monitor the parking lot, it would need to build another communication room or install a switch every 100 m, which can be expensive.  There are several techniques for increasing reach. The first is to use extender technology with traditional PoE solutions that feature a single power interface and transmit power and data over only two pairs of cabling. The extender is connected to the power sourcing equipment (PSE) and powered via the PoE input. The drawback of this two-pair powering approach is that the resulting PoE solution can then only support 10/100 Ethernet data applications—four-pair powering is required to support the gigabit data rates of PDs such as pan/tilt/zoom (PTZ) cameras, 802.11n access points, thin clients, WiMax transceivers and video phones. For the complete article, click here