Basic Facts about Power Over Ethernet (PoE)

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Basic Facts about Power Over Ethernet (PoE)

Power Over Ethernet (PoE) is a networking technology that enables Ethernet cables to carry electrical power in addition to data packets. In PoE enabled networks, direct current (DC current) travels over a single Cat6 or Cat5e Ethernet cable. PoE technology-enabled devices are designed to comply with at least one or multiple IEEE standards. Let us share which PoE standards are available to date.

Thus, this technology can bring significant cost reductions and simplicity in any small to medium office network. However, it is essential to understand that you cannot stretch a PoE link beyond the maximum link distance of 100 meters. On the other hand, in conventional ethernet networks, dedicated power cables and power supplies are used for the associated loads.

Conventional (Non PoE) Ethernet VS. Power Over Ethernet (PoE)

The following two images are showing how PoE is different from conventional Ethernet. As you can see, in conventional Ethernet, DC power is being provided from an external source. Whereas, in PoE, the connected devices are receiving the necessary power + data from a PoE enabled switch.

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PoE Applications – Examples:

Power Over Ethernet (PoE) technology can be used in a broad range of applications because various PoE compatible devices are already available on the market. Following is a list of devices that can easily be integrated into a PoE enabled network:

Ethernet Extenders
Industrial Control Devices
Network Switches
Security Cameras
VoIP Phones
Wireless Access Points
PoS Kiosks
Security Access Control Devices

Security systems, industrial automation and smart homes are some of the areas where PoE technology is often preferred.

Why Prefer PoE?

Time and Cost Savings – in a PoE network, both the networking signals and electrical supply can be transported through a single, Ethernet cable. This results in excellent cost savings. Moreover, you won’t need a certified electrician for planning, installation, and maintenance of various associated device's electrical connections.

Better Flexibility – In a PoE network, devices can be positions and relocated easily because keeping them near to electrical outlets is not a requirement. Thus, you can enjoy better flexibility through this technology.

Integrated Safety – PoE switches and injectors come with built-in safety features. The devices connected with PoE enabled networking equipment do operate under integrated protection for; overload, overcurrent, overvoltage, undervoltage, and various other fault conditions.

Plug & Play Connectivity – PoE deployments are done on a plug and play basis. In these networks, the addition and subtraction of devices can be processed without putting the entire network at a halt. You can easily add more devices on the network provided that there is sufficient power available.

Reliable Power – With PoE networking infrastructure, you can stay assured that the critical devices are getting power from a reliable source. In most cases, PoE injectors or switches are fed from the UPS system. Thus, you can extend an uninterrupted power supply to all your networked devices without laying additional electrical cables and without using additional adaptors.

PoE Limitations

Power Over Ethernet (PoE) technology has some limitations as well. The simple PoE network cannot be stretched beyond 100 meters. However, you can use additional equipment to achieve greater link distances. Another issue is related to non-compliant devices. In this case, you will require PoE splitters to keep using your existing non-PoE devices. Limited power resource is another big issue related to PoE systems. With better planning and power budget management, you can design a robust system.