What is PoE?

Power over Ethernet (PoE) is a technology that allows electrical power and data to be transmitted over standard Ethernet cables, enabling devices such as IP cameras, wireless access points, and VoIP phones to receive both power and data through a single cable. This eliminates the need for separate power sources, streamlining installation and reducing cable clutter. PoE technology adheres to standards set by the IEEE, specifically 802.3af, 802.3at (also known as PoE+), and 802.3bt (PoE++), which define the power levels and data transmission capabilities for various applications.

IEEE STANDARDS

To carry the power over this Ethernet data cables, certain IEEE standards are defined. These standards define properties of the established link, what is the maximum DC power which can be safely transferred over the network cables, what is the range of DC voltage, what should be the cable resistance, what is the allowable maximum current over the link

IEEE 802.3 af – Provides up to 15.4 W of DC power on each port

IEEE 802.3 at – Provides up to 25.5 W of power for “”Type 2” devices

IEEE 802.3 Bt – Provides up to 55 W for “Type 3” and up to 90-100 W for “Type 4” devices.