What is Power over Ethernet (PoE)?
Power over Ethernet (PoE) is the process of sending electrical power and data over copper wire.
The combination of data transmission along with power-supplying hardware onto the same RJ45 Ethernet connector allows for the transmission of power over the network cabling. PoE networks can source power at the network switch side or at a PoE injector to add power to an existing data line.
Power over Ethernet is a process where devices known as power sourcing equipment (PSE) provide a direct current (DC) voltage over a standard Ethernet cable to another connected device known as a powered device (PD). This allows for the powering of devices without the need for a local power source at the device location or having to run a separate cable for power.
Power Over Ethernet Standards
The Institute of Electrical and Electronics Engineers (IEEE) is the governing body that creates standards for Ethernet and other data communications. The first governing document created for PoE was 802.3AF, which states that compliant Power over Ethernet switches deliver 15.4W of power to guarantee delivery of 12.95W at the endpoint.
What is PoE+?
Improvements to this standard came in the form of 802.3AT, also known as PoE+, which states that Power Sourcing Equipment can provide 30W of power to ensure 25.5W at the endpoint. To guarantee a successful negotiation, both the switch and the endpoint device must be IEEE compliant. However, some device manufacturers have created their own implementations of PoE.
There are three main techniques for transmitting power over Ethernet cabling. These are Mode A (also known as common-mode data pair power), Mode B (spare-pair power), and 4PPoE (4-Pair power). With Mode A the power is provided on the same cable pair as the data pairs used in a 10Base-T or 100Base-TX transmission. With Mode B the spare pairs are used and with 4PPoE all 4-pairs of the Ethernet cable are used for power transmission.
Power over Ethernet Classes
The Power over Ethernet Class is reserved for powered devices (PD). The class specifies how much power the PD requires to function. There are currently 9 PoE classes ranging from 0 to 8. In most cases, the datasheet of a PD will display the PoE Class of the device or at least the IEEE standard it adheres to in the power, power consumption, or electrical sections.
Maximum Distance for Power Over Ethernet
Over the past 30 years, Power over Ethernet technology has seen incredible innovation. Initially, one of the primary downsides of PoE was the limited reach of 328ft (100m). However, new PoE innovations, like those from NVT Phybridge, are pushing the limits of Power over Ethernet transmission over several cable types. For example, the NVT Phybridge CLEER24-10G switch delivers power and data up to 6,000ft (1,830) over a single coax cable. That’s 18 times farther than a standard reach Power over Ethernet switch. Likewise, the NVT Phybridge FLEX24-10G switch delivers power and data over 2 or 4-pairs of UTP cable (Category 5/6 cable) with up to 2,000ft (610m) reach.
Advantages of Power Over Ethernet
PoE provides four primary advantages: lower infrastructure costs, fast and simple deployments, improved LAN design, and reduced e-waste.
Endpoint devices require two connections: data and electrical. The data connection allows communication with the network while the electrical connection powers the device. Separately installing both connections is costly and unnecessarily complicated, especially when considering the number and location of the devices across the organization. Power over Ethernet provides both connections using a single wire.
Many companies will install a PoE switch fabric when modernizing from older, analog voice and security systems, or when deploying a new system. NVT Phybridge PoE switches provide numerous benefits:
Lower Infrastructure Costs
Companies are saving millions of dollars in network readiness costs while avoiding the unforeseen challenges that come with an enterprise-wide network overhaul. These cost savings are realized through significantly reduced labor, cabling, and construction costs, which are often reallocated into devices and applications to improve return on investment.
The extended reach capabilities significantly reduce IDF closet requirements – including space, power, cooling, and backup power – to reduce cost, network complexity, and to simplify network management.
Fast and Simple Deployment
Deployments using Power over Ethernet technology are quick and easy, especially when leveraging network infrastructure that is already in the building. Simply install the PoE switch in the MDF closet, connect to the new or existing network cabling, and connect the device at the endpoint location.
Improved LAN Design
Organizations have the freedom to establish or maintain a physically separate Power over Ethernet network, or centrally converge to the core network using a single wire in a highly secure and controlled manner. This applies to both Cloud and on-premise solutions and significantly improves network security and performance. Quality of service is enhanced while ongoing network management is simplified as IT teams continue to manage the core business network while voice/security teams can handle these separate networks.
By repurposing existing infrastructure and reducing/eliminating IDF closet requirements, organizations are significantly reducing the environmental impact of their digital transformations. Far less cabling and equipment e-waste is produced. NVT Phybridge Power over Ethernet switches are built with PowerWISE technology to ensure low energy consumption, power redundancy, and hot-swappable power supplies.