Over the past decade, Power over Ethernet (PoE) has become an important power supply technology and has undergone a revolution from PoE to PoE+. Based on this technology, structured cabling can be used to provide power and data transmission channels for many network devices. With the rapid development of new services such as WLAN, VoIP, and network video surveillance, PoE+ has gradually become the mainstream. Using a switch that supports PoE power supply not only eliminates power cabling, but also has many other advantages, such as more flexible networking, saving labor costs, and convenient management.

However, with the advent of high-power applications, the maximum power supply of 30W is difficult to support the demand; in addition, whether it is 802.3af or 802.3at standard PoE switches, the power supply distance is usually only 100 meters. To achieve long-distance power supply and power transmission capacity increase, here we have to mention a standard protocol after PoE power supply upgrade: 802.3bt, which is a secondary enhanced Ethernet power supply standard, which is called PoE++.

The arrival of IEEE802.3bt heralds a new era of PoE technology entering a strong market opportunity. Let's briefly talk about the advantages of PoE++ compared to PoE and PoE+:

Expand the output power range : IEEE802.3bt will increase the maximum power of the power supply equipment from 30W to 90W, and increase the power level of the power equipment to 71.3W.

Extend power supply distance：The transmission distance of 100 meters can be extended to 200 meters.

Increased number of supported levels: IEEE802.3bt will increase the number of supported levels from 5 to 9 for Type 3 and Type 4 powered devices (PSE) and powered devices (PD) for 51-60W and 71-90W respectively .
  New features: The IEEE802.3bt standard provides many new features and new features, such as support for efficient 4-wire-to-power transmission, and channels that support 2.5 Gbps, 5 Gbps, and 10 Gbps PoE operation.

​

Comparison of power supply conditions of three power supply standards:

How is the expansion of the PoE++ power supply range and the extension of the power supply distance? Specifically, it should be analyzed from the following two points:

Pairs of line transmission power: 802.3bt standard uses 4 pairs of lines to transmit power, line pairs (1, 2) and (3, 6) provide 30W/45W power, pair (4, 5) and (7, 8) It also provides 30W/45W power for a total of 60W/90W power output.

Ethernet port bandwidth reduction: PoE++ reduces the network rate from 1000M/100M to 10M by technical means, and then increases the voltage amplitude of the RJ45 port of the PoE switch from 0.98V to 2.2V, thereby driving the data signal to the farthest. Over 200 meters.

In order to meet the 802.11ax wireless devices and various scenarios that require PoE++ power supply requirements, Sundray launched the Vsecure PoE++ switch RS3320-28M-4MT-PWR-LI, which supports several power modes of PoE, PoE+ and PoE++. Main features as follows:

20 Gigabit electrical ports, supporting 802.3af/at,(PoE/PoE+);

4 2.5G electrical ports, supporting 802.3bt(PoE++);

4 2.5G optical ports for uplink;

Sundray RS3320-28M-4MT-PWR-LI switch supports IEEE802.3bt standard, and the power supply capability is enhanced, in addition to support the previous common surveillance cameras, low-power building equipments (such as various IoT sensing devices, etc.), IP video phones. In addition to PoE equipment power supply, it can also support the power supply of retail stores (POS), video conferencing terminals, public communication terminals, building controllers, 802.11ax wireless APs, AI cameras, etc. The available scenarios can be further broadened.