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Power over Ethernet brings power to the people

PoE switches are an ideal solution for enterprise networks as they save deployment costs, reduce cabling requirements and provide vastly increased reliability.

Power over Ethernet (PoE) has revolutionized the global networking market by transmitting data and power over a single Ethernet Cable. PoE switches are an ideal solution for enterprise networks as they save deployment costs, reduce cabling requirements and provide vastly increased reliability.

PoE allows remote or outside equipment to be installed without requiring a connection to AC power. Power, therefore, can be delivered to more areas without the need to install additional electrical infrastructure, or requiring power outlets at every endpoint.

Personal computer, phone and WiFi equipment can be installed without an electrician having to do additional wiring. Because ethernet cable costs less and is often already installed in new buildings, PoE-based networks become much more cost-effective and efficient.

There are four different PoE types.  These types are grouped on factors including port power, wiring standards and compatible devices. To choose the right type that satisfies the power requirements of your network, sound understanding of the different kinds of PoE is crucial.

Keep reading to find the complete breakdown of the four PoE types, their distinctions and where they are used.

Type 1 (802.3af or PoE)

PoE Type 1 was introduced in 2003, with the IEEE 802.3af standard. This type of PoE device provides a maximum of 15.4W per port and a minimal 12.95W for each device. If 15.4W of power is supplied at the switch, one would expect 12.95W of delivered power. The energy lost would be due to the transmission through the Ethernet cabling.

Type 1 supports category-3 (Cat 3), category-5 (Cat 5/5e), category-6 (Cat 6/6A/6e) and category-7 (Cat 7) cabling, with a maximum resistance of 20 ohms per pairset and a maximum current of 350mA.

PoE can supply power using Mode A and Mode B in 10BaseT and 100Base-Tx. Type 1 PoE can support low-powered devices like static surveillance cameras, most grey scale and some color VoIP phones, meters, sensors and low power wireless access points.

Type 2 (802.3at or PoE+)

The Institute of Electrical and Electronic Engineers (IEEE) released PoE Type 2 (called “PoE+”) in 2009. It’s based on the 802.3at Ethernet standard, considered an upgrade from the 802.3af standard. Type 2 PoE which is also known as PoE+ can deliver up to 30W at the port level with a minimum guaranteed power level of 25.5W.

The voltage range at the Power Sourcing Equipment (PSE) – such as a switch – will be around 50-57V, while the voltage range at the Powered Device (PD) will be within the 42.5-50V range. PoE+ supports 4 pin/2 pin, Cat 5/5e, Cat 6/6A/6e and Cat 7 cabling, with a maximum cable resistance of 12 ohms and a maximum current of 600mA. It can also run devices that are supported by Type 1 PoE.


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Like the PoE network, PoE type 2 also provides power through 2 pairs and supports Mode A and Mode B. Type 2 devices are capable of providing power for motion-activated security cameras, LCD screens, all grey scale and almost all color VoIP phones, all low power and most high power indoor wireless access points with six antennas, indoor security cameras, and biometric sensors.

As an example of how to know what power your device may require, see the photo below. Noting the formula of Volts x Amps = Watts, all we would have to do is take the required input voltage and the required input amperage and multiply these together to see the power required.

The value circled in black (48-55v) represents the voltage range within which the device works. The value circled in red (0.6A) shows the current requirements. Multiply the voltage by the amperage to get the wattage: 48V x .6A=28.8W.  This would need Type 2 or 802.3at or PoE+

Below this note is another example.  Again, input voltage x input amperage = power required: 48V x .6A=28.8W.

Type 3 (802.3bt or PoE++ or UPOE)

To meet growing demands for more power at the end of the Ethernet cable, the IEEE 803.3bt released the 60W PoE standard in 2011. Type 3 PoE, also known as 4-pair PoE, 4P PoE, PoE++ or UPOE offers four times the power of Type 1 and twice the power of Type 2.

This type of PoE can provide 60W-100W of power to the source point, and 51W to every connected device. How? Power is delivered via all four pairs of twisted ethernet wires, unlike Type 1 and Type 2 which use two pairs.


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802.3bt supports Cat 5e or better (Cat 6/6A/6e and Cat 7) Ethernet cables with speeds of between 2.5 Gbit/s and 5 Gbit/s. Cables that transfer power using PoE Type 3 can withstand maximum current flow of 600 milliamperes per pair, and maximum resistance of 12.5 ohms. This standard is also energy efficient because it significantly minimizes power loss. Many high power devices such as video conferencing equipment, Pan Tilt Zoom cameras and building management devices require PoE++.

Type 4 (Higher power PoE, 802.3bt)

PoE Type 4 is currently the quintessence of all existing PoE technology. As the name suggests, it possesses the highest power capabilities among PoE standards. Higher power PoE was released in 2018, to help satisfy increasing power requirements of IoT and networking devices. It carries 90W of power from the source and inputs 70W of power to each device. If needed, it possesses the capability to support upto 100W of power from the source.

Connected cables can handle a maximal value of 960mA and 12.5 ohm of current and resistance respectively through them. Type 4 PoE has the same cable requirements as the Type 3 PoE.

It has the potential to support highly power-hungry devices like laptops and LED screens.

At NetworkTigers, we understand your company’s ever-growing power requirements. We offer a comprehensive range of innovative and cutting-edge networking solutions to help your network run as smoothly as possible.

802.3af, 802.3at, 802.3bt, PoE, Power over Ethernet 

Feba Maryann
Feba Maryann
Feba Maryann is a freelance journalist who writes for websites and magazines in Asia and North America. She is currently pursuing her Integrated Masters on Computer Science Engineering with a specialization in Data Science from VIT, Vellore.

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