Thanks to the Ethernet standard, we can count on networks as they are today. It is one of the fundamental standards that allowed millions of devices to communicate with each other. Its standardizations also contributed to its adoption being truly massive. In this guide, we will meet the PoE (Power over Ethernet) standard , which allows it to be possible to supply electrical power to a large number of networked devices, through the same Ethernet network cable through which we pass the data.
The acronyms in English correspond to Power-over-Ethernet. In Spanish, basically, they mean power over Ethernet. Refers to the transmission of electrical energy to compatible devices. This is possible using the same network cable that allows connection to local area networks. One of its main advantages is that it is no longer necessary to have exclusive wiring for power, such as the popular AC wiring and the special sockets that are usually placed near the devices so that they can work. This is ideal for devices such as indoor or outdoor Wi-Fi access points or IP cameras among other devices.
As we can see, the network cable has two main functions: data transmission and electrical power. Much more practical!
PoE as IEEE 802.3af standard
Doing a bit of history, PoE has become a standard with the IEEE 802.3af designation. The maximum output power from the power supply is 15.4 Watts. On the other hand, the categories of Ethernet cable that it supports are the typical Cat5e onwards, although it is always recommended to use Cat 6 today since the value for money is very worthwhile.
Despite the fact that the maximum power mentioned is 15.4 Watts , the actual power received is 12.95 Watts . This is so because the electrical energy is “lost” with distance. However, this does not affect the performance of devices connected via Ethernet, either with 10, 100 or 1000 Mbps links.
Devices that can be powered by PoE are VoIP phones, sensors, and wireless access points. In addition, it is possible to feed static security cameras (those that do not move from side to side, or from top to bottom). It can power any device that requires a low level of electrical energy, and that logically is compatible with the PoE standard.
PoE + or 802.3at
It is an improvement over the original PoE and one of the most important features is that it has backward compatibility with the previous standard. As a standard, it is called IEEE 802.3at . Unlike the previous standard, it has a maximum output power of 30 Watts, the actual power received is 25.50 Watts . Also, it can power devices that need more electrical power.
Some of the devices that we can power are: simultaneous triple band access points, biometric sensors and any type of LED screen. Speaking of security cameras, it is now possible to power using PoE (with its PoE + variant, of course) to those that have more advanced functionalities such as zoom and side-to-side movements, and therefore need more power .
PoE ++ or 802.3bt
The standard has been improving over the years, mainly because it seeks to supply the different devices on the market with greater electrical power. As a standard, it is called IEEE 802.3bt . Consequently, PoE ++ was born which is subdivided into two types: Type 3 and Type 4.
- Type 3, with a maximum output power of 60 Watts , the actual power received is 51 Watts .
- Type 4, with a maximum output power of 100 Watts , the actual power received is 71 Watts .
In any case, the four pairs of cables typical of the typical Ethernet cable are fully used. Type 3 is capable of supplying power to more demanding devices in terms of electrical power requirements, such as dedicated video conferencing systems. On the other hand, Type 4 already manages to power more modern devices such as IoT type, laptops and even Smart TV:
An important fact to keep in mind is that the manufacturer Cisco has its version of PoE in relation to PoE ++. This version is known as UPoE and its acronym in English correspond to Universal Power over Ethernet. The maximum output power it currently offers is up to 90 Watts. PoE + capabilities are virtually similar, with some additions and enhancements geared toward Cisco networking solutions, which have a high level of acceptance around the world.
Note: They are mentioned as Type 3 and Type 4 since the previous PoE and PoE + standards are also known as Type 1 and Type 2, respectively.
Is it really in my best interest to use some PoE standard?
It is clear that one of the direct objectives of this standard is to eliminate the need for the installation of equipment for electrical power. Consequently, there is a significant savings in the costs of implementing a network.
Also, people who are not exactly involved in networks can perceive the advantages of using PoE. It will be much easier for anyone to know that they are already managing to give electricity to a device (IoT equipment, for example) using a single cable and, in turn, connectivity. In the long term, you will not have to think at all which is the cable to disconnect from the current, which is from the network, which one I should not disconnect, etc. PoE can be considered as one of the most practical standards that we can meet.
We are increasingly connected. Almost all the objects that we use or those that are around us require electrical energy to function. Or in other cases, they require electrical energy and, in turn, connection to the grid. All this, 24 hours a day, 7 days a week for several of those devices such as access points, that is, the demand for energy consumption grows a lot and that is quite expensive.
PoE is aware of this aspect and one of the focuses of the newest of its standards is the efficiency of electrical energy. This is because all Category 5e Ethernet cable pairs are used. In previous standards, only two of the four available pairs were tapped.
Constantly growing technologies like IoT benefit greatly from power over Ethernet. PoE ++ provides support for IoT products such as bulbs, which need powerful but efficient power supply at the consumption level. In addition, this standard has a good level of performance if the device is in the stand-by state.
