5 Key advantages of Power over Ethernet(PoE)
5 Key advantages of Power over Ethernet(PoE) - Table of contents:
What is Power over Ethernet(PoE)?
Power over Ethernet(PoE) is a technology for implementing wired Ethernet local area networks (LANs) that enables the electrical current necessary for operating each device to be carried by Ethernet data cables instead of standard electrical power cords and wiring.
PoE technology sends 10/100/1000 Mbps of data and 15W, 30W, 60W, and up to 90W of power budget to devices over Cat5e, Cat6, and Cat6a. Cat7 and Cat8 Ethernet cables for a maximum distance of 100m.
PoE technology relies on the IEEE 802.3af, 802.3at, and 802.3bt standards set by the Institute of Electrical and Electronics Engineers and governs how networking equipment should operate to promote interoperability between devices.
How does PoE work?
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.
If it is not PoE-compatible, a component called a picker, or tap must be installed to extract the current from the cable. This picked-off current is routed to the power jack.
Power over Ethernet is used both in smart home applications and business premises, PoE uses cheaper Ethernet cabling, which can transport both power and data, instead of electrical wiring, which supplies power only and requires separate wiring for data.
Because PoE transports both power and data over Ethernet cable, less wiring is necessary, and electrical wiring can remain intact.
What are 802.3af and 802.3at PoE standards?
The Institute of Electrical and Electronics Engineers (IEEE) is responsible for creating PoE standards. There are currently three PoE standards available.
The 802.3af standard supports 15.4W of power. But even though 802.3at power sourcing equipment (PSE) can transmit 15.4W of power, powered devices (PDs) can only reliably receive 12.95W of power due to power dissipation.
In 2009, the IEEE introduced the 802.3at standard (also known as PoE+). This standard supports 30W of power, but similarly to the 802.3af standard, power dissipation causes PDs to receive slightly lower amounts of power, specifically 25.5W of power.
802.3bt (also known as PoE++) was ratified in 2018 and has two types (Type 3 and Type 4) offering higher power. The 802.3bt (Type 3) standard supports 60W of power, with PDs receiving 51W. The 802.3bt (Type 4) standard supports 100W which dissipates on the receiving end to 71.3W.
This new standard essentially combines Mode A and Mode B to achieve the higher voltage and support 10 Gbps connections.
What devices use Power over Ethernet(PoE)?
Equipment built to the 2003 PoE standard initially delivered enough power for most APs but could not provide enough power for other types of mounted technology, such as video surveillance cameras.
Over the years, the Institute of Electrical and Electronics Engineers (IEEE) and several vendors have attempted to address the power issue, but interoperability problems have persisted.
Power over Ethernet supports the following devices that consume 30 watts (W) of power or less:
- Internet Protocol, voice over IP, and video telephones;
- Worldwide Interoperability for Microwave Access, or WiMAX, and wireless AP devices or nodes;
- Pan, tilt, and zoom robotic cameras;
- Remote computer terminals, computer monitors, laptops, thin client computers, and large computer display screens;
- LCD display screens and large TVs;
- Door access systems and video signing displays;
- Network audio.
In 2018, IEEE released IEEE 802.3bt, a new PoE standard also known as high-power PoE or PoE+. It accommodates the use of four-wire pairs with Cat5 or Cat6 cable, which supports individual devices that require as much as 90 to 100 W of power. Devices this standard supports include the following:
- Light-emitting diode lighting
- Security card readers
- High-performance wireless APs
- Video conferencing
- Video surveillance cameras
5 advantages of Power over Ethernet(PoE)
1. Easy installation.
There are no worries about hooking into electrical system outlets.
2. Cost savings.
Ethernet can carry both power and data signals.
PoE automatically stops power current flows if there is a service interruption.
4. Data speed.
Power over Ethernet 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).
POE devices attached to networks with high-level security enjoy the same security protection as other network assets.