What is PoE – Power over Ethernet?

What is PoE – Power over Ethernet?

PoE, or Power over Ethernet, is a low voltage technology. It covers a method for reliably delivering DC power and data to remote devices. Presently, the need for network equipment and device connections is experiencing exponential growth. And, as a result, the cost and time of deployment are set to rise.

To minimize cable usage and expense, Power over Ethernet (PoE) technology can be used, whereby utilizes a single twisted-pair Ethernet cable such as Cat 5e or Cat 6 cables, to deliver both data connectivity and low voltage power to devices.

How Does PoE Work?

Power over Ethernet (PoE) demands a powered device (PD) and power sourcing equipment (PSE) contained in the solution. This ensures that the solution is a complete circuit. This verifies that the solution is a complete circuit. A PSE is positioned at the originating end and generates power and data. Power and data are delivered to the PD by the PSE through cat5e or cat6 cable. The PD functions as an end device, receiving power and data from the PSE.

Power-over-Ethernet (PoE) technology allows network cables to transport electrical power avoiding the need for additional electrical wiring. It enables network planning flexible and independent of switch sockets and cabinets, minimizing the need for additional wire costs. Devices can be placed wherever structured Ethernet cable exists, without the requirement for AC power outlets locally.

Consider a security camera: when it is installed, it generally includes two connections: a network connection to communicate with video recording and display devices, and a power connection to give the electrical power needed to operate the camera. However, if this surveillance camera is PoE compatible, all we need is a network connection because it may also get electrical power from the cable.

How to Add PoE to Your Network?

You may encounter a circumstance in which it is necessary to install IP phones, wireless devices, or IP cameras in locations where AC power outlets are not accessible. What would you do in that situation? Installation of additional power supplies and wiring can be labor-intensive and time-consuming. The most practical solution is to implement PoE (Power over Ethernet), a system established by IEEE802.3 that provides low voltage power to Ethernet-enabled devices across the communication line. In this section, we’ll show you how to convert your existing network to PoE.

Before converting your current network to a PoE-enabled version. You should start by emphasizing that this system includes a power sourcing equipment (PSE) and powered devices (PD).  Power over Ethernet compatible network end device that accepts power provided via structured Ethernet cable is referred to as a PD.  PSE supplies DC power to PD.  A PSE can be either an Endspan or a Midspan device.  An Endspan device is often a network switch that is configured to offer PoE power on each port. A Midspan device adds electricity to the line by being connected to each end device.

The Basic Ways to Add Power to Your Ethernet Network

PoE Switch

A PoE switch is a network switch that provides power over Ethernet injection. Simply by linking other network devices to the switch, it will identify whether they are compatible with power over Ethernet and then enable power automatically. This type of switch is available for a wide range of applications, ranging from low-cost unmanaged switches with a few ports to complex multi-port rack-mounted units with extensive management.

Midspan Device

Midspan provides PoE functionality to a standard network switch. Midspan can be used to update existing LAN setups to PoE. Midspan is also a versatile choice when fewer ports are required. Each network connection can be upgraded to power over Ethernet by simply patching it through the Midspan device.

PoE Splitter

It is also possible to use a splitter to update powered devices (PDs) to power over Ethernet-capable ones. This splitter links to the camera’s network connection and taps into the PoE power, transforming it to a lower voltage sufficient for the camera.

PoE Standards

Modern PoE standards allow for increased power transmission, which broadens the variety of devices supported in the enterprise and, to some extent, contributes to the surge in PoE adoption rates.

PoH (Power over HDBASET) provides video, audio, 100Mbit/s Ethernet, and power. The POH standard is based on the 802.3at standard, which has been amended to allow for the delivery of up to 100 W via a 4-pair Cat 5e or 6 cables. TIA and ISO are also updating cabling standards to support 4-pair PoE in accordance with 802.3bt.

The TIA TSB-184 guidelines for implementing power supply over balanced twisted-pair cable, as well as the ISO/IEC 11801-6 distributed building services working draft, are raising Cat6a cabling specifications to better support IEEE 802.3bt four-pair PoE and other applications.

 Cabling for PoE

The heat generated in cable bundles can have a major impact on network performance. Heat can cause increased insertion loss, shorter allowable cable lengths, and higher power costs due to greater power dissipation in the cabling. Temperatures in the cable should not exceed the cable’s temperature rating. The Telecommunications Industry Association (TIA) recommends 15 degrees as the maximum allowed temperature rise above ambient as a result of power over the cabling.

Ways to help lower cabling temperature in PoE deployment

Reduce the Number of Cables Per Bundle
Separating large cable bundles into smaller bundles or avoiding tight bundles helps to keep higher temperatures to a minimum. A bundle of 91 cables has a higher temperature than three bundles of 37 cables. Furthermore, physically separating the three bundles reduced the maximum temperature even further.

Choose a Higher Rated Category Cable
Higher-rated cable often has greater gauge sizes, so when power currents increase, the larger conductors will outperform smaller gauge cable. TIA test finds that higher category-rated cable allowed for larger bundle sizes under the maximum 15-degree temperature increase. The acceptable bundle size was 52 cables for Cat 5e, 64 for Cat 6, 74 for Cat 6a. Higher-category cabling can accommodate more current capacity at the maximum permissible 15 degrees.

Do not use CCA for PoE
Copper-clad Aluminum is not as good an electrical conductor as copper. Because it has a higher DC resistance than copper, more power is lost and dissipated as heat (the longer the cable connection – the worse it gets). Higher heat and more power loss on the cable are both important concerns in PoE applications, so using them with PoE injectors or switches is not recommended.  As a result, it is evident that using higher category cable with bare copper conductors is essential for minimizing temperature increases. Cat6a cable is recommended to supports the greatest data throughput of 10GBASE-T and has no bundle size constraints with any current or future PoE application, it is recommended for all new installations.

The Pros & Cons of PoE

The benefits of Ethernet power would include fact that it is constantly available, which considerably boosts mobility for end devices. PoE is also safer to use because it does not require AC power. Furthermore, it simplifies installation and operation by eliminating the need for additional AC power wire, keeping cabling secure while not interfering with network performance. This makes power over Ethernet a considerably more secure, dependable, and cost-effective alternative.


  • Save Time & Money – By minimizing the time and costs of building electrical power cables. Network cables do not need to be installed by a certified electrician and can be placed anywhere.
  • Flexibility – Devices that are not tied to an electrical outlet can be placed where they are most needed and conveniently moved.
  • Security – PoE delivery is proactive, and it is intended to safeguard network equipment from overload, underpowering, and faulty installation.
  • Reliability – PoE power is supplied by a centralized and universally compatible source. It can be powered by an uninterruptible power supply or remotely operated to simply disable or reset devices.
  • Scalability – having sufficient power on the network means that installing and distributing network connections is straightforward and efficient.


  • Inadequate Power -The past generation of PoE power supplies has various power inadequacies. They can, in particular, offer adequate power to ordinary pan, tilt, and zoom cameras; nevertheless, they may not deliver enough electrical energy to high power consumption devices such as network PTZ cameras.
  • Power Dependent – Another disadvantage of the PoE system is that a single PoE power source or switch is typically used to power numerous powered devices. If any of these PoE network devices malfunctions, all of the devices will stop functioning.
  • Cost – Lastly, using PoE to power standalone devices is relatively expensive. In fact, providing a dedicated electrical connection for a reliable system may be less expensive in the long term, but it is not quite as flexible as a PoE line.


PoE technology is an ideal choice for enterprise networks due to its simplicity in mixing signal and power in a single Ethernet cable connection. In this situation, PSE can offer power to a wide range of PD in places where AC power is unavailable. Deploying this technology in your network will provide a safe, dependable, and cost-effective method of delivering consistent and dependable power to standard networking devices.

Using higher category cable to allow for greater bundle sizes and to provide higher current capacity. Additionally, to lower temperatures, aim to reduce the number of cables per bundle when cabling for PoE.

Choosing higher-quality cabling is one of the most important factors in attaining performance, reliability, and flexibility in PoE.

Alpha Cable offers Premium Cat 5e, Cat 6, and recommended Cat 6A cables with bare copper conductors for your next PoE installations.

Visit our site for all Alpha’s Network Ethernet cables.

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