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Power over Ethernet Explained

Power over Ethernet (PoE) is a technique for supplying DC power to technology devices via copper Ethernet cabling. Therefore it eliminates the need for a separate power supply and outlet. Although PoE does not include Ethernet data capabilities, it does offer extended options for where and where to place Ethernet end devices. In other words, Power over Ethernet explained is showing that it is a technology for Wired Ethernet Local Area Networks (LAN). It permits the electrical power necessary for the operation of each device to be carried through data cables instead of local power cords. Doing so reduces the number of wires that are attached to the network. PoE was originally developed in 2003 to support devices such as Wi-Fi access points (APs). Therefore PoE made Access Point installations easy and flexible, especially on rooftops and externally.

How Power over Ethernet works and why it is used?

The main reason for using PoE on technology systems is to reduce the cost of a power supply to each device connected to the network. For example, if you have 10 cameras distributed throughout the building. In this case, they would need 10 power supply units to supply power and this is not the main problem. The main problem is the wiring of power sockets near each device. Thus this is not always practical. The cameras already require a data cable for image transmission. In this instance it can carry our both roles. Therefore using PoE to connect all the devices to the central network is the best choice.

Now let’s look at the functions of these devices and how they can be used.

PoE Injector

This unit has two input ports and one output port. The first input is to connect the normal Ethernet cable and the second input is to connect the DC power supply, while the output is used to connect the PoE / Ethernet cable. At the input we have: General Ethernet connection + DC power supply. At the output, we have PoE Ethernet (which can be used to connect PoE devices). Therefore, the PoE injector function is providing POE Ethernet with a normal Ethernet connection and DC power supply.

PoE Splitter

This device has one input port and two output ports. The input is for connecting the Ethernet cable, while the output ports provide normal Ethernet and DC power. We have input: PoE Ethernet and we have output: Normal Ethernet connection + DC power supply. Therefore, the function of the POE splitter is the exact opposite of that of the PoE injector, which is to divide the PoE Ethernet connection into normal Ethernet and usable DC power supply.

PoE Extender

A PoE extender is used when covering large distances such as network spans such as shopping malls, hotels, restaurants, office buildings, businesses, educational campuses, and sports venues. These places usually cannot use a 100 meter Ethernet connection and this is when the PoE Extender comes into play. This device can be used to extend Ethernet network devices beyond the basic 100-meter distance, making it a viable option for many cases.

A large majority of peripheral devices support PoE Ethernet so we can connect the cable straight to the device. This setup will work if there are one or two appliances but if there is more than one appliance then buying a POE injector for each device is not the best solution. Therefore for such specific cases, we have a PoE switch that can replace multiple PoE injectors.

PoE Switches

A PoE switches function is similar to that of a PoE injector except it provides a lot of PoE Ethernet outputs. This center is best used if you have a lot of PoE devices on one end and normal Ethernet connectivity providing the server on the other. So far we have assumed that there are free lines available in existing Ethernet cables that can be used for PoE without much difficulty.

The switch can be used as either a PoE device or a standard data switch. Therefore it is scalable for when you add or remove PoE devices to the other end of the data cabling.

PoE Standards

PoE devices follow certain standards for data communication and power transmission. Therefore, these standards are followed when designing these devices. In general, four types of standards are followed when designing these devices and they are divided based on their ability to handle power.

Advantages of PoE

Easy and Low-Voltage Installation

PoE is a low voltage power option, usually less than 60 volts. It speeds up installations and reduces the hazards associated with general electrical work. Furthermore it dramatically reduces the overall installation cost.

Data Analytics

Data brings clarity to smart building technology. Thus enabling information gathering and intelligent optimization. Because the data travels over both sides via an Ethernet cable, the PoE software sends data and commands to the devices It addition it also provides helpful insights on usage and operation. Thus further cost savings, and opportunities to enhance the occupants’ quality of operation.

Cost Savings

The biggest advantage of PoE technology is cost savings. PoE installation is cheaper than traditional electrical work. This is because the cabling is already required for data. Thus operating costs are lower over the life of PoE. It also results in less disruption as routing new electrical cables would be destructive in some cases

Enhanced Flexibility

Once installed, PoE controlled devices can be disconnected and connected to a new PoE system with minimal downtime. Furthermore users have more control over their smart building ecosystem. This is because network data flows across all connected devices. These devices feedback on their operation allowing better service and maintenance

Secure and Reliable

Unlike devices that rely on wireless technology, the Ethernet cord allows significant flexibility while maintaining a reliably connected system. PoE eliminates the risk of wireless interruptions and allows users to enable additional security features.

Data speed

One of the reasons for the increase in access to PoE technology is that data speeds are improving at a rapid rate. It can now provide data at 1 Gbps (10/100/1000 Mbps) using Cat5 and Cat6 cables. The new IEEE 802.3bz can deliver speeds from 5 Gbps to 2.5 Gbps over 100 meters with an instant view to the standard 10 Gbps. Most high-defense streaming requires 400 Mbps, which enables the network to efficiently manage streaming videos and perform other tasks such as email checking.

Disadvantages of PoE

Power insufficient

The power-powered device cannot boot 802.3af PoE The standard maximum output power is below 15.4W, which is enough to supply power to most IP cameras. However, the output power is not sufficient for high power devices such as network PTZ cameras.

Centralised risk

Normally, a PoE switch connects to multiple IP cameras, and if the PoE network switch encounters any problems, all IP cameras will stop working.




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