Introduction to Power over Ethernet (PoE)
Power over Ethernet, or PoE, is a technology for wired Ethernet networks that allows network devices to be powered by the data cable instead of an external power source. PoE standards define the amount of power that can be safely delivered to a device, and how that power is delivered. There are three major PoE standards: 802.3af, 802.3at, and 802.3bt.
802.3af was the first PoE standard, released in 2003. It defines two classes of devices: Class 0 devices can draw up to 12 watts of power, while Class 1 devices can draw up to 25 watts. Most network devices, such as VoIP phones and WiFi access points, are Class 0 devices.
802.3at was released in 2009 and increased the maximum power delivery to 30 watts. It also introduced a new class of device, Class 2, which can draw up to 60 watts of power. This standard is sometimes referred to as PoE+ or PoE Plus.
The most recent standard, 802.3bt, was released in 2018 and defines four classes of device: Classes 3 and 4 can draw up to 90 watts of power, while Classes 5 and 6 can draw up to 100 watts. This standard is also sometimes referred to as Ultra PoE or UPoE.
PoE standards are important because they ensure that powered devices will not overload the data cable or cause electrical safety hazards. They also allow for a greater
Types of PoE Standards
PoE standards define the types of devices that can be powered by PoE, as well as the maximum power level that can be delivered. The most common PoE standards are IEEE 802.3af and 802.3at.
IEEE 802.3af is the original PoE standard, released in 2003. It defines a maximum power level of 15.4 watts and is compatible with a wide range of devices, including phones, cameras, and access points.
IEEE 802.3at is an updated version of the 802.3af standard, released in 2009. It increases the maximum power level to 30 watts, allowing it to power more demanding devices such as pan-tilt-zoom cameras and video phones.
There are also a few proprietary PoE standards that have been developed by individual manufacturers. These standards typically offer higher power levels than the IEEE standards, but are not compatible with as many devices.
-IEEE 802.3af
IEEE 802.3af is a standard for Power over Ethernet (PoE) that was ratified in 2003. It defines both the power delivery and data communication protocols for PoE devices. The standard provides up to 15.4 watts of power per port, which is sufficient to power most small VoIP phones, wireless access points, and other low-power network devices.
One of the key advantages of IEEE 802.3af is that it is compatible with existing Ethernet infrastructure. This means that there is no need to install new cabling or make other changes to your network in order to deploy PoE devices. Additionally, 802.3af-compliant devices are inter-operable, so you can mix and match products from different vendors without worrying about compatibility issues.
-IEEE 802.3at
IEEE 802.3at, also known as PoE+, is the latest power over Ethernet standard. It was ratified in 2009 and provides up to 25.5 watts of power per port, with a maximum of 30 watts per device. This allows for greater flexibility in terms of what devices can be powered by PoE+, as well as increased power for devices that require it.
One of the key advantages of IEEE 802.3at is that it uses all four pairs of wires in an Ethernet cable, instead of just two pairs like previous versions of PoE. This allows for more power to be delivered over the same amount of cabling, which reduces costs and installation time. Additionally, it is backward compatible with older versions of PoE, so you can still use your existing cabling infrastructure.
-IEEE802.3bt
The IEEE 802.3bt standard, also known as PoE++ or 4PPoE, is the latest Power over Ethernet standard released in September 2018. It defines new requirements for delivering up to 100 watts of power to devices over Ethernet cabling.
The 802.3bt standard builds upon the existing 802.3af and 802.3at standards by adding support for higher wattage devices and new cabling types. This allows for the powering of devices such as video cameras, Wi-Fi access points, and LED lighting fixtures directly from an Ethernet cable.
There are two main benefits of using the 802.3bt standard:
- Increased Power Delivery – The increased power capabilities of the 802.3bt standard allow for more devices to be powered over Ethernet cabling than ever before. This can reduce installation costs by eliminating the need for separate power supplies and wiring for devices such as video cameras and LED lights.
2 . Improved Cable Compatibility – The 802.3bt standard introduces new cabling types that are compatible with a wider range of Ethernet hardware than previous standards. This makes it easier to find compatible cables for your particular application, and also reduces the likelihood of cable compatibility issues when upgrading network hardware in the future
Advantages of each Standard
There are three main Power over Ethernet (PoE) standards: 802.3af, 802.3at, and 802.3bt. Each standard has its own advantages that make it well-suited for different applications.
802.3af is the oldest and most common PoE standard. It can provide up to 15 watts of power, which is enough to power devices like IP phones and Wi-Fi access points. However, it is not powerful enough to run devices like HD video cameras.
802.3at is an updated version of 802.3af that can provide up to 30 watts of power. This makes it ideal for powering devices that require more power, such as HD video cameras or multi-port switches.
802.3bt is the newest PoE standard, and it can provide up to 60 watts of power. This makes it ideal for powering devices that require a lot of power, such as 4K TVs or large LED displays.
Conclusion
Power Over Ethernet (PoE) is a great way to provide electrical power and data communication over the same cable. By utilizing this technology, businesses can realize cost savings by eliminating dedicated cabling for network devices and reducing installation time. The various PoE standards enable users to customize their systems to meet specific needs while ensuring compatibility with any type of device. With its many advantages, it’s no wonder that PoE has become one of the most popular standards in networking today.
