Language
Country/Area
No result found
The secret of PoE technology: How to make a network cable transmit data and power at the same time?
In today's digital era, as the number of devices increases, the demand for network infrastructure is increasing. Power over Ethernet (PoE) has become an important solution to this need. This technology allows a single Ethernet cable to not only transmit data, but also provide power at the same time, facilitating the operation of various devices such as wireless access points (WAPs), web cameras, and VoIP phones.
How PoE works
The core of PoE technology is to use twisted pair network cables to transmit power and data simultaneously. This technology has multiple standards developed by the Institute of Electrical and Electronics Engineers (IEEE). The three most important standards include:
Alternative A: Utilize the same pair of signal lines in 10BASE-T and 100BASE-TX data transmission.
Alternative B: Separate data and power conductors to aid troubleshooting.
4PPoE: Uses four pairs of twisted wires for parallel transmission, significantly improving power transmission capabilities.
PoE application scenarios
A variety of devices can benefit from PoE technology. Here are some typical applications:
- VoIP phone
- IP camera (including PTZ type)
- Wireless Access Point (WAP)
- Network Router
- Small network switch supports multiple Ethernet ports
These devices may have required multiple power adapters in the past, but PoE technology can effectively simplify this process and reduce installation and maintenance costs.
The development of various PoE standards
Since 2003, IEEE began to standardize PoE technology. The first standard, IEEE 802.3af-2003, provides up to 15.4W of power per port. Subsequently, the standards continued to evolve:
IEEE 802.3at-2009 (PoE+) provides power supply up to 25.5W.
IEEE 802.3bt-2018 (PoE++ or 4PPoE) provides higher power, including 51W Type 3 and 71.3W Type 4.
Advantages and challenges of PoE
Although PoE technology provides a lot of convenience, it also faces some challenges. For example, because Ethernet cables have a relatively low voltage, they are not as efficient as alternating current (AC) power supplies. However, while PoE provides centralized management, it can effectively reduce redundant power lines and equipment.
Looking to the future
With the popularity of the Internet of Things (IoT) and smart homes, the application of PoE technology will become more widespread. By integrating PoE with other energy-efficient technologies, such as IEEE 802.3az's Energy Efficient Ethernet (EEE), it is more likely to achieve considerable energy savings.
As technology continues to advance, how will PoE evolve in the future to adapt to changing needs?
