POE (Power Over Ethernet) refers to the technology that existing Ethernet Cat.5 cabling infrastructure without any changes can transmit data signals for some IP-based terminals (such as IP telephones, wireless LAN access point AP, network camera Etc.) while transmitting data signals, but also provide DC power supply for such devices.  POE technology can ensure both the safety of existing structured cabling and normal operation of existing networks, which minimizes costs.

POE power supply principle

The standard Category 5 cable has four pairs of twisted pairs, but only two of them are used in 10M BASE-T and 100M BASE-T. IEEE80 2.3af allows two kinds of usage, the application of idle feet power supply with, 4,5 feet connected to the positive and 7,8 feet connected to the negative.

When the application of data feet power supplies power, the DC power supply in the midpoint of transmission transformer does not affect the data transmission. In this way the pair 1, 2 and the pair 3, 6 can be of any polarity.

Advantages of POE Switch in the Application of Monitoring System

1. power transmission up to 100 meters with easy wiring

POE switches use PoE technology to power up to 100 meters for network equipment, making wiring easier.

2. applied to security monitoring field and compatible with all types of network switches

Million high-definition securities dedicated PoE switch is mainly used in the field of monitoring, so the compatibility of the network camera project has become one of the important features of the PoE switch.

PoE switches are compatible with network cameras, mainly in two areas. The first is PoE power supply function. PoE switches use the international standard IEEE802.3af / at the design and the industry's leading network cable 8-core power supply cross-way (1236 and 4578 line order can be powered at the same time power supply) which reduces the network material loss more than half than the similar products. The transmission power of the end terminal is higher, driving distance farther.

Second is the data communication function. Security monitoring has a higher demand on the switch's throughput and delay. Fluency and stability of video transmission are security monitoring network elements.

3. multiple thermal design to improve stability and extend product life

Compared to ordinary switch, PoE switch products have more power than the general switch and larger chip heat, so the excellent cooling solution is an important guarantee for the stability of the PoE switch.

4. A strong data processing capability to ensure the stable operation of the network

The switch's backplane bandwidth is the maximum amount of data that can be handled between the switch interface processor/interface card and the data bus. It marks the total data exchange capacity of the switch. The higher the backplane bandwidth of a switch, the stronger the ability to process the data, but the higher the design cost.

Comparison with traditional power lines

The traditional power line power supply is good, but it cannot adapt to the rapid development of the current network monitoring. With the construction of the safe city, surveillance cameras are all over the streets, such as the intersection, shopping malls, hotels, supermarkets, schools, KTV, etc. They are large, so how to supply them with stable power supply is a very troublesome thing. It is impossible neither to dig pipes and put wiring in the streets nor to install any power outlet. In this case, a PoE switch can deal with it. Network monitoring transmitting data through the network cable can achieve the data and power transmission of the cable at the same time through the PoE switch can be achieved at the same time. With front-line, no wiring, no power outlet, it still can give countless camera power supply.

The use of PoE switches not only eliminates the need for power wiring, but also has many other advantages, such as more flexible network free from routing restrictions,  saving labor cost, higher security with no more power, later maintenance and  simple and convenient management, intelligent power supply guaranteeing power equipment safety, more environmentally friendly energy and so on.

How to choose a POE switch?

Small monitoring system can achieve stable power supply by using one or several PoE switches; medium and large monitoring system uses switch cascade, that is, select the access layer switches, convergence layer switches, and the core layer switches. In fact, regardless of the size of the network monitoring system, as long as the PoE switch selected is right, it can stabilize the power supply, and provide more smooth and HD video streaming transmission.