➡️ Introduction: What is IEEE 802.3at (PoE+)?
The IEEE 802.3at standard, widely known as PoE+, is the second generation of Power over Ethernet (PoE) technology. Ratified in 2009, it builds upon the original IEEE 802.3af PoE standard, nearly doubling the available power. With PoE+, a single Ethernet cable can deliver both high-speed data and up to 30 watts of electrical power, enabling the deployment of more power-hungry network devices without additional power supplies or adapters.
➡️ Power Delivery: From PoE to PoE+
The primary advantage of IEEE 802.3at lies in its enhanced power capacity:
IEEE 802.3af (PoE):
Maximum power at PSE (Power Sourcing Equipment): 15.4 W
Available power at PD (Powered Device): 12.95 W
IEEE 802.3at (PoE+):
Maximum power at PSE: 30 W
Available power at PD: 25.5 W
This significant increase makes PoE+ suitable for next-generation IP-based equipment that demands higher wattage. Importantly, 802.3at remains backward compatible with 802.3af, ensuring seamless integration into existing infrastructures.
➡️ Key Applications of IEEE 802.3at (PoE+)
PoE+ extends the range of powered devices beyond what standard PoE could support. Common applications include:
IP Cameras with PTZ (Pan-Tilt-Zoom) & IR illumination
High-performance Wireless Access Points (Wi-Fi 5/6/6E)
VoIP Phones with color displays and advanced features
Thin Clients and Small Network Switches
Industrial and IoT Devices requiring reliable mid-level power
By consolidating power and data into one cable, PoE+ simplifies deployment, reduces cabling costs, and improves scalability.
➡️ Technical Features of IEEE 802.3at
Backward Compatibility: Supports both PoE (802.3af) and PoE+ (802.3at) devices.
Intelligent Power Detection: PSE automatically identifies if a connected device supports PoE before supplying power, protecting non-PoE devices.
Flexible Cabling: Operates over Cat5e or higher Ethernet cables.
Midspan or Endspan Deployment: PoE+ can be integrated into switches (endspan) or via midspan injectors.
➡️ IEEE 802.3at vs IEEE 802.3bt (PoE++)
While 802.3at delivers up to 30W, the newer IEEE 802.3bt (PoE++) standard pushes the limits further, supplying up to 60W (Type 3) or 100W (Type 4). This makes PoE++ ideal for high-power devices such as pan-tilt-zoom cameras with heaters, multi-radio wireless APs, or even laptops.
For network engineers and integrators, understanding the differences between PoE+ and PoE++ ensures selecting the right infrastructure components for scalability and performance.
➡️ LINK-PP Solutions for PoE+
To fully leverage IEEE 802.3at and IEEE 802.3bt standards, high-quality Ethernet magnetics are essential for stable data transmission and efficient power delivery. LINK-PP, a leading supplier of magnetics for Ethernet connectivity, provides robust solutions tailored for PoE networks:
🔹 PoE+ RJ45 Magnetics Jack: Designed for IEEE 802.3at compliance, supporting up to 30W power delivery with excellent EMI performance.
🔹 PoE+ Magnetics Transformer Modules: LP41223NL 10/100 Base-T Single Port Transformer Modules Engineered For IEEE 802.3at PoE+ Application.
These components ensure safe, efficient, and high-performance PoE deployment across enterprise, industrial, and IoT environments.
Conclusion
The IEEE 802.3at (PoE+) standard has become a cornerstone of modern networking, enabling cost-effective and scalable deployment of power-hungry devices through a single Ethernet connection. With higher power capacity, backward compatibility, and wide application potential, PoE+ bridges the gap between traditional PoE and the next-generation PoE++ standard.
For organizations building future-ready networks, choosing reliable PoE magnetics is critical. LINK-PP’s PoE+ solutions provide the performance, safety, and scalability required for enterprise and industrial applications.
