With the arrival of wireless technology, Power over Ethernet (PoE ) may seem like an obsolete technology. The truth is not.

Power over Ethernet plays a vital role in powering devices such as VoIP phones, IP cameras, and APs over the single UTP cable used for data.

In its early stage, PoE technology was a hybrid package of home-brewed proprietary methods. And many home-brewed and proprietary schemes were employed to get power over network cables. However, the IEEE 802.3af/at standard has gained universal adoption as PoE's popularity has spread. Now, this technology is used everywhere and is a particularly viable option for powering smart buildings.

Despite the remarkable progress PoE has made, doubts about technology persist to this day. Let's take a look at a few of the most common them.

On the contrary, PoE technology is totally reliable. Relying on the well-known Ethernet technology, the IT teams could easily update the PoE technology in their existing networks. The only thing you need to do is wire up the networking as usual, and the PoE equipment will take care of power delivery. Second, with power manageability and battery backup, PoE can prevent power outages and spikes.

One of the main features of PoE is flexibility. The PoE could be used wherever needed, as this technology does not require an outlet connection. It is particularly suitable for APs and IP cameras.

There are so many variables that it’s difficult to answer that question. But if you make an apples-to-apples comparison, you’ll find that implementing PoE will most likely make the entire project less expensive.

First, there is no need for a separate electrical supply line with PoE. Namely, there is a substantial reduction in installation labor costs – that is a licensed electrician need not be employed to make the installation.

Second, PoE systems are maintenance-friendly, although not especially cost-effective as mentioned above. The user can enable it to shut down at night automatically and remotely reset to collect relevant information from network devices such as servers, printers, hubs, and switches, which are managed efficiently through a Simple Network Management Protocol (SNMP).

Third, PoE enables network improvements that further reduce costs. With PoE, you can install the network devices such as IP cameras or sensors away from the grid without more AC power lines.

Finally, a PoE system can be attached to an uninterruptible power supply (UPS). This fact means that mission-critical systems can be assured of a constant power supply even if regular electrical service is interrupted.

As PoE-powered IoT networks expand widely, more and more power-consuming devices are born. Unfortunately, the PoE standard, such as IEEE 802.3at, is only applicable to low-power devices with up to 30W of power through Ethernet and limits the power budget available for intelligent networks and devices, which need to be driven by the power of 60/90W. However, the latest version - IEEE 802.3bt - allows a max of 90W of power to be delivered to a single PD. Today, the semiconductor industry is actively pushing to reduce the power consumption of individual transistors, which allows integrated device manufacturers (IDMs) to do more work with less power. As a result, the industry has more power budget available to PDs, as well as PDs that require less power to do more work.

Engineers now have a much larger power budget to work with before considering the use of offline power and all its attendant costs. With these facts in mind, it is accurate to say that PoE can meet the requirements of more applications than ever before.

UTEPO new-launching PoE splitters split the PoE signal to RJ-45 port & DC power port, RJ-45 port & USB Type-C power port, RJ-45 port & Micro USB power port, which are born for application to different-interface terminals, such as Raspberry Pi series, mobile phone, tablet, Dropcam, IP camera, Echo Dot, and more. While making PoE more widely available and the rest free PoE ports are full of used, it also makes your project wiring a breeze.

Instead, it is transforming smart buildings. There was a time when PoE was used primarily for VoIP telephone and IP cameras. However, PoE technology has evolved to the point where it is now used to enable numerous devices, including human-centric lighting, occupancy sensors, asset tracking, access control, and more.

As the Internet of Things (IoT) expands, the number of PoE applications continues to increase as well. The number of IoT endpoints is increasing every year. Many of these will be smart sensors or actuators that use only a few amounts of power but must be connected to the Internet. Many of today's more popular wireless protocols continue to provide IP addresses. Therefore, they must connect using a local gateway that is likely to use a wired Ethernet connection to the Internet. Adding PoE to these local gateways is an inexpensive option. Wireless endpoints require power, usually provided by the primary battery (which needs to be replaced) or using offline power (which requires an AC-DC converter). Using PoE eliminates the need for raw batteries, offline power, and wireless connectivity. IoT security is always an issue and is closely tied to wireless connectivity. A wired Ethernet connection would greatly reduce these concerns, as it requires physical access to the endpoint.

Finally, PoE is reliable and stable, with no problems such as RF congestion or packets that need to be resent.

When it comes to conductors originally designed purely for data, engineers are understandably concerned about signal integrity and power dissipation. Therefore, it is important to note that the IEEE 802.3 specification was developed with these issues in mind.

For example, the IEEE 802.3bt standard requires the following.

● This 90W of power must be transmitted through all four twisted pairs within the cable.

● The maximum cable length is 100 meters.

● In the case of using only two twisted pairs, the maximum DC loop resistance should not exceed 12.5 ohms.

● Use Cat5 or higher gauge cable.

As long as these specifications are met, power dissipation will not be an issue.

The IEEE 802.3bt is entirely backward-compatible with IEEE 802.3af (12.95 W) and IEEE 802.3at (25.5 W)—and allows a mixture of PoE standards to coexist in the same network. Therefore, new PSEs or PDs on an existing network will not be needed.

Conclusion

Power over Ethernet technology has evolved in tandem with the development of IoT devices as a secure and reliable power source. With the latest generation of IEEE 802.3bt, there is higher power, more efficient transmission and backward compatibility.