Power over Ethernet delivers electrical power to PoE-enabled devices using your CATx (CAT-5, CAT-6, etc.) network cables. Since you don’t need to run electrical wiring, PoE saves money in materials and install time. It’s also flexible, especially for remote applications, since it doesn’t require a nearby electrical outlet. These and other benefits have led to a big increase in its popularity in recent years. However, the limiting factor has always been power.
Sounds like magic. How does it work?
The way Power over Ethernet works is simple. Ethernet cable that meets CATx standards consists of four twisted pairs of cable. Simply put, Power over Ethernet sends power over these pairs to enabled devices. First PoE standards use two twisted pairs to transmit data, while the remaining two pairs are used for power transmission. However, the new standards allow power and data to be sent over all four twisted pairs.
We hear what you’re thinking, and the answer is no. When the same pairs are used for both power and data, the power and data transmissions don’t interfere with each other. That’s because electricity and data are transported at opposite ends of the frequency spectrum. Electricity has a low frequency of 60 Hz or less, and data transmissions have frequencies that can range from 10 million to 100 million Hz.
And PoE +?
Standard Power over Ethernet provides 15.4w per port. It is compatible with Gigabit Ethernet ports. On the other hand, PoE+ will provide up to 30w per port. It is backwards compatible with PoE. It can also negotiate the power output it supplies to end devices. Essentially, it has a greater power budget that ordinary PoE.
If your network is currently PoE, you may not need to upgrade to PoE+. For example, if you’re spec’ing things like VoIP you’re probably fine right now. That’s because the power level required won’t be unmanageable with the lower standard. However, if you’re looking to build out a more robust,future-proof network with many varied devices and don’t want limitations on what you can plug into a port, then PoE+ is the right choice.
In the long run, POE+ costs more. But, it will save you a lot of headaches when devices that require higher power levels do come onto your network.