What devices powered by PoE?
Devices that can be powered by PoE include:
- Network routers
- WAPs
- VoIP phones
- IP TV (IPTV) decoders
- IP cameras including PTZs
- In remote locations, a mini network switch is used to connect a small cluster of Ethernet ports to a single uplink cable. Power over Ethernet (PoE) is supplied to the switch through a PoE in port, which can then be used to power remote PoE devices via PoE pass through.
- Intercoms, public address systems, and hallway speaker amplifiers.
- Wall clocks in rooms and hallways, with time set using Network Time Protocol (NTP).
- Outdoor roof mounted radios with integrated antennas, 4G/LTE, 802.11 or 802.16 based wireless CPEs (customer premises equipment) used by wireless ISPs.
- Outdoor point to point microwave and millimeter wave radios and some Free Space Optics (FSO) units usually featuring proprietary PoE.
- Industrial control system components including controllers, sensors, meters etc.
- Intelligent lighting controllers and Light-Emitting Diode (LED) Lighting fixtures
- Access control components including intercoms, keyless entry, entry cards, help-points, etc.
- Inline Ethernet extenders
- Power over Ethernet (PoE) splitters can distribute power, typically at a non-standard voltage like 5V, for the purpose of powering a remote device or charging a mobile phone.
Terminology
Power sourcing equipment
Power sourcing equipment (PSE) refers to devices that supply power through the Ethernet cable. Such equipment can be a network switch, known as an endspan (referred to as endpoint in IEEE 802.3af), or an intermediary device placed between a non-PoE switch and a PoE device, which is called a midspan device or an external PoE injector.
Power devices
A PD, short for powered device, refers to any device that relies on PoE for power, resulting in energy consumption. This category includes devices like wireless access points, VoIP phones, and IP cameras.
In order to provide flexibility, many powered devices come with an additional power connector that allows for the use of an external power supply. Depending on the device’s design, it may receive some, none, or all of its power from this auxiliary port. In certain cases, the auxiliary port may also serve as a backup power source if the PoE-supplied power fails.
Power management features and integration
Supporters of PoE anticipate that it will become a universal, long-term standard for DC power cabling worldwide and replace numerous individual AC adapters that are difficult to manage centrally. Detractors argue that PoE is inherently less efficient than AC power due to its lower voltage, which is exacerbated by Ethernet’s thin conductors. However, proponents of PoE, such as the Ethernet Alliance, point out that the cited losses are based on worst-case scenarios regarding cable quality, length, and powered device power consumption. Additionally, in cases where a centralized PoE supply replaces multiple dedicated AC circuits, transformers, and inverters, the power loss in cabling can be justified.
The collaboration of EEE and PoE
The combination of PoE and the IEEE 802.3az Energy-Efficient Ethernet (EEE) standard has the potential to generate even more energy savings. Early implementations of EEE and PoE, like Marvell’s EEPoE as described in a white paper from May 2011, suggest that it could save up to 3 watts per link. This level of savings is particularly important as more high-powered devices are connected to the network.