5G Powered By Power Over Ethernet: An Ethernet cable is typically used to transfer data. In fact, the same cable can also be used to supply power to connected network devices.
Power over Ethernet (PoE) is a technology that transmits electrical power through a twisted pair Ethernet cable: the device that provides the power is called Power Sourcing Equipment (PSE) while the powered one is called Powered Device (PD).
Most PSE equipment is a network switch or PoE injector intended for use with non-PoE switches. Common examples of PD devices include VoIP phones, wireless access points, and IP cameras.
Silicon Labs has introduced a new portfolio designed to power future Ethernet applications such as 5G mini cells. The PSE and PD products comply with the new IEEE 802.3bt 90W PoE standard.
Power Over Ethernet Technology
PoE technology, sometimes also called “in-line power supply”, allows you to significantly reduce the number of cables needed to install a network. Other benefits include greater flexibility in choosing the location of installed equipment, reduced downtime and reduced wiring and power costs.
Since its introduction in 2003, power delivery capacity via Power over Ethernet (PoE) has increased dramatically from the original 15.4 watts to 30 watts. A new standard, IEEE 802.3bt, addresses this need by increasing power to 60 watts and in some applications to 90 watts. The IEEE 802.3bt standard introduces Type 3 and Type 4 PSEs/ PDs.
The new Power over Ethernet (PoE) standard – IEEE 802.3bt – enables higher power level for new applications while supporting 10 Gigabit Ethernet (10GBASE-T) and maintaining compatibility with older PoE standards.
PSE equipment has a maximum power budget, which represents the total amount of power it can deliver to PD devices simultaneously, measured in Watts.
Most PSE equipment does not have a power budget that’s high enough to provide the maximum power for all PoE ports, as most users do not use all the power. Therefore, most PSE equipment implements power management to intelligently distribute power between the connected PoE ports.
When a PD is connected to a PSE, the PoE standard specifies the inrush current to the PD to prevent high current spikes. In addition, the PoE standard provides an analog handshake (classification) between the PSE and PD to negotiate power.
The PD requests a particular class of power, and the PSE either grants the requested class or demotes the PD to a lower power level. After the classification is complete, the PD reports the available power to the PD system controller, and the PD system must adjust its power draw accordingly.
Silicon Labs Solutions
Silicon Labs’ new PoE portfolio provides a complete solution with the goal of reducing the cost and complexity of adding 90 W PoE to power sourcing equipment (PSE) and powered devices (PD). The new 90 W PoE portfolio is IEEE 802.3bt compliant.
By more than doubling PoE power, the portolio expands the capabilities of wireless access points, IoT wireless gateways, and other PoE applications. The portfolio’s higher power capabilities help make small 5G PoE-powered cells and digital buildings a practical reality.
The portfolio includes three new PSE and PD products: the 802.3bt compliant single-port 90W PSE Si3471 controller. The Si3471 does not require external host MCUs, firmware downloads, or software programming and is easy to configure using three digital I/O pins.
The Si3474 quad Ethernet 90 W 802.3bt or up to eight 30 W 802.3at/af PoE ports for industrial and commercial Ethernet switches and safety recording equipment.
The Si34071 single-chip PD solution combines an 802.3bt interface with an integrated high-efficiency dc-dc converter that achieves over 90% end-to-end efficiency. Si34071 provides high power for small 5G cells, wireless access points, and IoT gateways (Figures 2-4).
“A key benefit of Power over Ethernet is the ability to deliver power and data over existing, standard Ethenet cables,” says Charlie Ice, a senior product manager for power products at Silicon Labs “This eliminates the need to run AC mains to installation locations for connected devices, which in turn reduces the cost and complexity of installation.
For example, deploying 5G small cells throughout a building typically involves installing systems in hard to reach places without access to AC power. By using PoE technology, a single, low-voltage Ethernet cable can extend to the small cell to provide high-speed data and up to 71 W of power.”
PoE is useful when you are in the condition of having to power and use a network device in places where a wall outlet is not available nearby. This is the simple case with IP cameras for video surveillance in places where power cannot easily be brought in.
Usually, you are looking for devices that incorporate a long-life battery. Video surveillance solutions, sensors, transmitting and receiving devices, and other IoTs are just some of the possibilities offered by PoE.
“With the new 90 W standard being ratified last year, we think that PoE is going to really explode in terms of the number of applications and customers designing with it.
Not only will PoE be used for 5G small cells, it’s also going to reinvigorate wireless access points and other PoE applications,” says Kevin Kilbane, a senior product manager for power products at Silicon Labs.
The use of PoE functionality allows developers to reduce the number of cables and electrical outlets required in environments with a high concentration of equipment or inside a wiring cabinet.
In an age when wireless dominates, Ethernet may seem like yesterday’s technology, but it is felt everywhere.
It will even be crucial in delivering 5G services, thanks in part to Power over Ethernet and the latest iteration of the specification, which increases the total power available on a single 90W connection.