Power over Ethernet, or PoE, allows both data and power to be delivered over a Cat5e or Cat6 Ethernet cable. By eliminating the need for separate electrical wiring, PoE reduces the time, complexity and costs associated with powering a variety of networked devices.
Powered Device (PD) – A device that receives power through the Ethernet cable. Examples include security cameras, wireless access points, VoIP phones, sensors, etc.
Power Sourcing Equipment (PSE) – The device supplying power to the Ethernet cable:
- PoE-Capable Network Switches (Endspans) deliver power and data to PDs
- Power Injectors (Midspans) are placed between non-PoE switches and PDs
Types of PoE Devices
Extenders – The maximum length of an Ethernet cable is 100 meters (328 ft.) but this can easily be extended using a hub or switch. In PoE applications, an extender is used to "repeat" both the data and power, extending the cable run another 100 meters. This can be done a number of times before power degrades below the requirements of the PD.
Splitters – To power a non-PoE device, a splitter draws power from the Ethernet cable and passes it to the device via its power port.
Media Converters – Transparently convert fiber to copper and provide power to PoE-compliant devices such as IP cameras, VoIP phones and wireless access points. A media converter is a type of PSE (it requires an AC power source) and is typically used when extending a data network beyond the limits of Ethernet.