Power over Ethernet (PoE) technology first appeared in the late 1990s and was primarily used to power IP phones. Since its introduction, PoE technology has struggled to meet expectations. As with many new technologies, the hype far exceeded its initial capabilities, partly due to standards only supporting PoE devices capable of running on less than 15 watts of power.

It wasn't until 2018 that the Institute of Electrical and Electronics Engineers released its 802.3bt standard, which supported up to 100 watts of power on PoE devices. This advancement allowed PoE technology to support high-power devices, such as laptops, which require up to 70 watts in high-performance mode.

Another technology emerged around 1999, quickly becoming a driving force in PoE applications. When the Internet of Things (IoT) became a household name in 2014, it had already been around for at least 15 years, following a timeline similar to PoE. Integrating these two technologies has led to the construction of more environmentally friendly buildings with systems designed to optimize efficiency, resource allocation, and comfort—known as smart buildings.

What is a Smart Building?

Smart buildings integrate advanced technologies to improve building infrastructure operations. Smart technologies ensure that operational subsystems, such as heating, cooling, lighting, and access control, can share data to optimize resource usage. For example, occupancy sensors can send data to the lighting system when a room is unoccupied, ensuring the lights are off and adjusting heating and cooling systems.

What is IoT?

The Internet of Things (IoT) technological ecosystem consists of physical devices interacting with other systems via a network connection without direct human intervention. These devices could be lights, security cameras, thermostats, or sensors. These endpoints collect data and send it back to a management system that takes actions based on the information. For example, a room sensor could be set up to collect environmental data that can then be used to lower the temperature as it becomes more crowded. This setup can help ensure the environment remains comfortable regardless of occupancy levels.

What is IEEE 802.3bt?

The IEEE 802.3bt standard makes smart buildings work. Because of this standard, devices can be deployed in hard-to-reach places. Data can be transmitted over the network at up to 40 Gbps, making real-time, automated decisions possible. More sophisticated devices requiring more power can be added to enhance smart building functionality.

IEEE 802.3bt Standard

The standard supports two operational modes. Mode A is for Type 3 devices requiring up to 60 watts of power. Mode B supports Type 4 devices requiring up to 100 watts of power. Both modes use a Category 6 or 6a Ethernet cable. Data transmission speeds can reach 40 Gbps. It’s important to note that the higher the data transfer rate, the shorter the distance between the PoE device and its PoE power source. PoE extenders can be used to maintain quality of data over longer distances.

Why Use IEEE 802.3bt?

Smart buildings need the power and data transfer speeds provided by the IEEE 802.3bt standard. The data required for autonomous systems to function must be transmitted in real time. Knowing that an unidentified person is on a corporate campus 30 minutes after the first sighting reduces the security system's effectiveness. This standard also helps:

• Simplify Device Installation: PoE hardware does not require an external power source, just an Ethernet connection. This reduces the costs, and potential delays associated with installing electrical wiring are reduced.
• Simplify Network Management: Fewer wires mean fewer changes for electrical failure. If a device stops communicating, is it the network or the power source? Addressing the problem becomes time-consuming, especially if the device is located remotely.
• Simplify Device Monitoring: PoE-managed switches can report the status of all connected devices. They can initiate a reboot if the device is not communicating but has power. With standard support for up to 52 ports, consolidating devices under a managed switch eases the pressure of network uptime.
• Enhance Energy Efficiencies: Fewer electrical wires mean lower energy requirements. Reducing fossil fuel use helps reduce the carbon footprint and increases sustainability.
• Improve Reliability: Connecting an uninterruptible power supply (UPS) to a PoE power source means that devices can continue operating even if power is unavailable. Security cameras can still record activity, and environmental controls will continue to keep temperature-sensitive equipment safe.

PoE technology's IEEE 802.3bt standard can help facilitate the move to smarter and greener buildings.

How Do PoE Devices Improve Device Management?

The Edge in the Netherlands uses about 28,000 sensors to track energy and supply usage. It can shut down entire building sections when not in use and identify available parking spaces for employees. It uses every data point the sensors collect to make the office building more efficient. The property owner depends on the IT department to keep it running.

How Do You Monitor 28,000 Sensors?

Anyone involved in computer networking probably wonders how well their endpoints are being monitored and how many hours that monitoring will consume. Deploying PoE technology can ease this burden by keeping thousands of devices reliably operational.

PoE technology allows network architects to place devices where they are most needed. Placing sensors on a vaulted ceiling or a wall that catches the afternoon sun would be problematic when using standard electrical wiring, but with PoE, this type of setup only requires a single Ethernet cable. Adding extra sensors to capture applicable data becomes unnecessary. The Ethernet cable would then be connected to a power source, most likely a PoE-capable managed switch, where the data can be forwarded to a central location for analysis.

But, a PoE switch can do more than connect devices to the network. Switches come with built-in device management systems that provide topology mapping. Color-coded icons let network administrators know the status of any device connected to the switch at a glance. Auto-discovery features ensure that the visual displays are current.

On the Slope of Enlightenment

As technology gets smarter, PoE devices as part of IoT applications will continue to grow. With simplified installation, monitoring, and management capabilities, PoE can help network administrators deliver reliable performance and real-time data. Whether to facilitate lighting solutions, security systems, or environmental controls, PoE devices are, and will be, integral to smart buildings.