Power over Ethernet (PoE) Technology

In this Insights article, we explore the concept of Power over Ethernet, PoE, its applications, advantages, and implementation.

Power over Ethernet is a technology used to deliver DC power to compatible devices over Ethernet cabling networks, eliminating any need for separate power supplies and outlets. While PoE doesn’t add to Ethernet data capabilities, it offers expanded options on how and where Ethernet end devices can be placed.

While PoE has existed in offices worldwide, 200W PoE capability significantly improves options available when powering devices ranging from LED lighting, occupancy sensors and from cameras to monitors, window shades, USB-C-capable laptops and air conditioners and refrigerators. 

How does PoE work?

Power over Ethernet (PoE) allows Power Sourcing Equipment (PSE) or a switch to provide power and data collectively to Powered Devices (PDs) over standard Ethernet cables. In doing so, it replaces power cables with Ethernet cables, powering newer smart devices with specific power needs and also making power easily accessible to hard-to-reach remote devices such as outdoor cameras, access points, sensors, detectors, security devices, displays, digital signage, and many other PoE-capable devices. 

For PoE to work, the electrical current must go into an ethernet data cable at the power supply end and come out at the device end. With Ethernet, the power current can be kept separate from the data signal so neither interferes with the other.

Current enters the Ethernet cable via a component called an injector. If the device at the other end of the cable is PoE-compatible, it will function properly without modification. Power sourcing equipment (PSE) ensures seamless data and power connection, enhancing network scalability and flexibility. This technology simplifies installation by delivering DC power to compatible devices.

PoE Benefits

The advantages of PoE include the following:

• Ease of installation. There are no worries about hooking into electrical system outlets.
• Cost savings. Ethernet can carry both power and data signals.
• Safety. PoE automatically stops power current flows if there is a service interruption.
• Data speed. PoE can now deliver data at 1 gigabit per second (Gbps) — 10/100/1,000 megabits per second — using Cat5 and Cat6 cables. The IEEE 802.3bz PoE standard delivers speeds of 2.5 Gbps to 5 Gbps over 100 meters (m).
• Security. POE devices attached to networks with high-level security enjoy the same security protection as other network assets.
• Flexibility in device placement, allowing network devices to be placed in locations without easy access to outlets.
• Enables remote management, monitoring, and control of powered devices, making network maintenance and troubleshooting more convenient.
• Conforms to universal requirements, ensuring compatibility and standardisation.
• Reliable DC supply solution designed for data network applications.

PoE – Smart Buildings

A smart building converges building-wide systems (often referred to as building management systems – BMS, or building automation systems – BAS) including HVAC, PoE lighting, shades, alarms, and security – into a single, IT-managed network infrastructure. It often uses foundational technology such as Power over Ethernet to accomplish this convergence.

PoE has evolved from providing 15W of power across Ethernet cabling to providing 200W. With that evolution, the number and types of devices that can be powered and connected by PoE have grown dramatically.

• Public Address (PA) Systems: PA systems in various settings can be powered using PoE, reducing the need for separate power sources and simplifying installation.
• LED Lighting: PoE can power LED lighting systems, particularly in smart building applications. This allows for centralized control and power management of lighting systems.

PoE – Industry applications

PoE enables devices like Wi-Fi access points, security cameras, and VoIP phones across industries. It simplifies network setup, reduces costs, and enhances services. It is crucial in hospitality, education, government, Multiple Dwelling Units, public venues, and smart cities.

PoE solutions stand out in all these industries due to their efficiency, ease of deployment, and enhanced security. These solutions can support the unique needs of each sector, helping them deliver superior experiences and services.

PoE and non-PoE Devices

PoE will not harm non-PoE devices. The PSE has a detection phase determining whether the connected device supports PoE. If it doesn’t, the PSE won’t transmit electricity, thus preventing potential damage.

Conclusion

Power over Ethernet is an innovative technology transforming networking infrastructure across many industries, by delivering flexibility, simplicity, and cost savings, enabling data transmission and power over standard Ethernet cabling. With ongoing enhancements in power capacity and compatibility, PoE promises to expand into lighting systems, building automation, and IoT technologies.

PoE is therefore becoming an appealing alternative to installing separate DC and networking systems.

Pure energy (REGen) Ltd is currently working together with CISCO Systems Inc. and Schneider Electric SE, to provide renewable energy infrastructure design and installation services to support DC/DC power microgrid networks to selected clients, enabling Power over Ethernet (POE) technology applications within the UK.

Pictures courtesy of Cisco Systems Ltd and CSA Group