Power over Ethernet (PoE) is an updated concept defined by the IEEE 802.3/ PoE standards to simultaneously deliver power and data through the same Ethernet cable. The IEEE 802.3 standards were first initiated in 2003 to indicate the power requirements between power sourcing equipment (PSE) and powered devices (PDs). In the past few years, PoE technology basically relied on the IEEE 802.3af/at standards to regulate how network devices operate together to promote interoperability between the PSE and PDs.
With the expansion of IoT applications, the first and foremost challenge faced with the PoE technology is the amount of power it can provide. While the IEEE 802.3af specifies a power output of 15.4W, which is totally enough to power some low-voltage devices (i.e. IP phones, wireless access points and static security cameras), it still seems not enough for pan-tilt-zoom (PTZ) IP cameras and radio frequency identification (RFID) readers. Hence another updated PoE standard, called IEEE 802.3at, was released in 2009 with a maximum power of 30W at the PSE. Today, higher power is demanded to achieve centralized management when more network devices are added to the network, especially when powering high-power devices such as point of sales (POS) terminals, digital signage and LED lighting. In 2018, a new PoE standard IEEE 802.3bt was officially approved. This new standard specifies a power supply of at least 71W to the PDs at the maximum cable length.
IEEE 802.3bt: New Generation of PoE
IEEE 802.3bt is the latest generation of PoE standard and first-ever implements power over four twisted pairs of structured wiring. In IEEE 802.3af/at, only two twisted pairs are used for power connection, while data can be delivered over four pairs. And for the first time, this new generation of PoE uses all 8 wires to transport power, minimizing the power loss over transmission to achieve a better power-delivery system with a substantially increased power budget. The extra power allows more high-power applications to be added to the network.
It facilitates the expansion of PoE by pushing the power limits of PSE and PDs to 100W (the maximum power can be delivered on each port defined by the SELV requirements for safe and reliable operation without damaging the PoE ports and connected devices) and 90W (Max. in Type 4) respectively, which are unsupportable under the previous IEEE 802.3 standards. The first specification, IEEE 802.3af (Type 1) can provide up to 15.4W of output power at each PoE port over 2-pair Cat5e cable, while another slightly updated PoE standard IEEE 802.3at, also known as PoE+ or Type 2, is capable of delivering a maximum power of 30W at the PSE and 25.5W at PDs. The following chart provides a side-by-side comparison of the maximum power each PoE standard can deliver on a per-port basis.
What’s New in IEEE 802.3bt standard
The latest IEEE 802.3bt standard not only guarantees a higher power output over 4 twisted pairs but also brings additional features to the PoE standards.
New types and classes
The new generation of PoE introduces 2 new PoE types (Type 3 and Type 4) and 4 additional classes (Class 5-8). Type 3 is also known as PoE++ or UPOE, which can provide up to 60W at each PoE port (power available at the PD is 51W) to power devices like high-performance wireless access points (WAPs) and high-definition PTZ cameras. PoE classes (0-8) define the maximum power that can be sourced and drawn in the power system. Type 3 can support at least Class 4 (PSE:30W; PD: 12.95-25.5W) in 2 or 4 twisted pairs and support Class 5-6 (45-60W; 0-51W) in all 4 pairs. Commonly known as high-power PoE, Type 4 can supply maximum power output of 100W and 90W at PSE and PDs to power devices like flat screens and LED lighting over Cat6 cables. All 8 wires are required to support Class 7-8 (75-90W; 62-71W). And the IEEE 802.3bt standard is fully backward compatible with the prior PoE standards to work with legacy Type 1 and Type 2 devices with no problem.
Single and dual signature
The IEEE 802.3bt standard brings 2 new PD typologies, called single signature and dual signature. The single signature PD shares the same detection and classification signature between two pair sets, but the dual signature PD has two separate detection and classification circuits, so it has independently different signatures between two pairs with distinct supported loads and power classes. The previous PoE standards IEEE 802.3af/at cannot distinguish single-signature PDs from dual-signature ones, whereas the new IEEE standard enables the differentiation between these two types of devices via connection check. In a surveillance camera that features a dual-signature PD architecture, one pair can be connected to the camera, while the other pair can be connected to the heater or pan/tilt/zoom motor according to their power requirements to achieve the optimal power distribution.
Lower standby power
The new PoE standard show great improvements in the standby power consumption. In the IEEE 802.3af/at standards, the PDs must draw approximately 10mA for at least 75ms every 250ms in a duty cycle to keep the PoE port alive, which is extremely crucial for LED lighting and security systems to remain “ON” to ensure fast turn-on. Unlike the traditional lighting, the intelligent LED ballasts need to be constantly powered even when the light is off, but it also results in significant power wastage when a large number of PDs are deployed. IEEE 802.3bt offers a practical solution to reduce the minimum standby power to 20mW which is 10 times lower than the older IEEE standards (nearly 200mW at 54V).
High Power PoE++/UPoE Solutions
In the following sections, we’re gonna introduce some of the best high-power PoE solutions available at the Fastcabling and their applications in real life.
1. 10 Gigabit 95W BT PoE Injector
The 10 Gigabit 95W BT PoE injector compliant with the IEEE 802.3bt PoE standard offers a cost-effective solution to power multiple high-power devices, such as 802.11ac/ax wireless access point, high-definition PTZ cameras and LED lighting, with a significantly increased power budget at 10 Gigabit network speed with less latency. The high-power PoE injector can provide a maximum of 95 watts of power by using all 4 twisted pairs. It can be utilized to connect PoE and non-PoE devices using a single Cat5e/6 or higher-level Ethernet cable with a minimal impact on the existing network infrastructure. The wall-mountable injector features a simple plug-and-play design, offering great convenience and flexibility on installation. It is an energy-conscious supplementary device with lower power consumption.
2. 95W Waterproof PoE++ Splitter
This waterproof PoE++ splitter is an industrial-grade device suitable for outdoor deployments in harsh environments to power up high-power non-PoE devices when there are no available AC outlets nearby, saving the costs of installing new electrical outlets. It often works with a PoE injector or PoE switch enabling a maximum of 60W output power on each port to power some devices, such as POS terminals or other network devices that demand higher power to function normally. This 95W splitter supports backward compatibility with IEEE 802.3af/at standards to work with legacy Type 1 and Type 2 devices. It can work over a wide operating temperature from –40°C to 75°C with a metal IP67-rated housing to survive harsh weather conditions. It features a 6kv surge protection mechanism for safe and reliable operation.
More high-power PoE solutions like 802.3bt PoE switch are available at Fastcabling.
802.3bt PoE++ Enables High Power IoT Applications
1. 95W LED lighting
Using high-power PoE to supply DC power to the LED lighting without additional AC wiring is a viable solution to set up a smart lighting system from a centralized power source with integrated management and monitoring. As previously mentioned, the IEEE 802.3bt standard ensures the quick activation of the LED lighting with a lower standby power to reduce the overall power consumption. Since the LED lighting belongs to non-PoE devices, you’ll need a 95W PoE injector and splitter to set up the high-speed power connection. First, connect the injector to a regular Ethernet switch or an 802.3bt PoE switch and power the injector. Then connect the high-power injector with a splitter to separate the power from the data and feeds it in a different cable to the non-PoE devices. Lastly, connect the splitter to the LED lighting.
2. High-performance PoE WAPs
The demand for high-performance PoE WAPs is rapidly increasing in homes or workstations that utilize bandwidth-hogging applications, while the inability to deliver maximum power via PoE often blocks people from deploying such devices. However, the 10 Gigabit 95W PoE injector offers a practical solution to deliver a maximum power of 95W to these high-power WAPs deployed in hard-to-reach areas with a smaller footprint. For the deployment, you’ll only need a network switch and a 95W PoE injector. Connect the network switch with the injector with a Cat5e/6 cable, and then connect the injector with the high-performance WAP.
