PoE

Power over Ethernet (PoE) is a groundbreaking technology that allows electrical power to be transmitted along with data on Ethernet cables, thus enabling network cables to carry both data and electrical power to devices. This negates the need for separate power supplies or electrical wiring for network-enabled devices. PoE is particularly beneficial for devices that are situated in locations where a power outlet is unavailable or impractical to install. The technology is standardized under IEEE 802.3af, 802.3at, and 802.3bt, defining the power levels and methods of delivery. PoE can provide up to 100 watts of power, allowing it to support a wide range of devices.

Common Applications

VoIP Phones

PoE is widely used in powering Voice over Internet Protocol (VoIP) phones, simplifying installation by using a single cable for both data and power.

IP Cameras

Security cameras benefit from PoE by allowing flexible installation locations without the need for nearby electrical outlets.

Wireless Access Points

Wireless Access Points (WAPs) often utilize PoE to be positioned optimally for coverage, without concerns about power socket availability.

Network Switches

PoE can be used in network switches to power connected devices, creating efficient and scalable network setups.

Safety Considerations

Electrical Safety

PoE technology is designed to deliver a safe amount of power, with mechanisms in place to prevent overloading and short circuits. Devices and network equipment should be IEEE compliant to ensure safety.

Heat Generation

Devices powered by PoE may generate additional heat. It’s important to ensure adequate ventilation and consider the thermal environment in which PoE equipment operates.

Related Terms or Concepts

IEEE 802.3af/at/bt

These are the standards that define PoE specifications, such as power levels and delivery methods.

Midspan and Endspan

Midspan refers to PoE injectors that add power to the Ethernet cable, while Endspan is integrated into network switches.

Power Sourcing Equipment (PSE)

This term refers to devices that provide power in a PoE setup, such as switches or injectors.

Powered Device (PD)

These are devices that receive power via PoE, such as IP cameras, VoIP phones, and WAPs.