Distance Challenges with Power over Ethernet

Power over Ethernet (PoE) is a useful technology in powering remote devices, but as we see with any copper network cable, the challenge lies in the limited distances of UTP cabling.

The first example shows an Endspan PoE switch. This is an Ethernet switch with PoE Power Sourcing Equipment (PSE) capabilities built-in. In other words, the switch can put both data and power on the UTP cable. The Camera is PoE Powered Device (PD), and must be located within 100m of the Endspan PoE switch.

The second example shows a basic Ethernet switch connected to a Midspan PoE injector. The midspan injector has two UTP ports. The port on the left is connected to the data cable coming from the switch. The data passes through the injector, which adds the DC power to the cable as well. Midspan power injectors typically do not increase the 100 meter distance limitation of copper cabling in the network, because the 100m distance limit applies to the entire span – from UTP switch to PD.

Extend Distances to PoE Devices

On the left side of the application is a copper switch with RJ-45 ports that connects to the network. In this surveillance camera application, the switch is located in a control room and connected to video recording equipment. A miConverter or FlexPoint unmanaged media converter is used to convert the copper cabling from the switch to fiber optic cabling. The fiber can extend up to 140 kilometers, depending on the fiber type and optical power of the media converters.  

At the remote end, fiber is terminated by an OmniConverter PoE media converter located near a convenient AC or DC power source. The OmniConverter functions as both a media converter and PoE Power Sourcing Equipment. It converts the fiber to copper, and it injects PoE power (DC power) out the RJ-45 port to the UTP cable. A PoE Powered Device (PD) is connected to the other end of the UTP cable, and can be installed up to 100m away from the OmniConverter media converter.