Westward Sales Blog

There are so many possibilities in network design, that finding the right solution can be overwhelming. If you have wondered if Power over Ethernet (PoE) or a PoE injector is the right course for your project, then this guide is for you.  You’ll learn about PoE basics, cost saving opportunities, common applications and general reasons why you should or should not utilize PoE.

Advantages of PoE

Like any design choice, implementing PoE comes with its own set of pros and cons. In some cases, the trade-offs are beneficial to some systems but detrimental to others.

Safety

Perhaps the biggest selling point of PoE is its safety advantage.  Installing Ethernet cables requires no specialized electrical knowledge.  Deploying PoE allows you to skip the services of a certified electrician to run power to your devices. The lack of regulation around PoE deployment is not from oversight. The equipment is simply that safe.  And in many cases, it can improve the safety rating of a facility, occasionally leading to insurance discounts.

Cable Cost

Reduced cable cost is another primary benefit of utilizing PoE. Any network that employs Ethernet cabling can save substantial money by eliminating additional power lines. Of course, this advantage mostly applies to remote locations where traditional AC outlets are not readily available. One of the primary reasons to consider adopting PoE is when the existing power infrastructure does reach where your devices are mounted.  While the total savings will depend on your layout, power cables typically cost anywhere from $3 to $100s of dollars per foot. On average, choosing PoE over adding power lines will save around 50 percent of the total installation price.

Freedom of Design

Closely linked to the previous advantage is design freedom. PoE allows you to mount networking devices, e.g., IP cameras, alarms and sensors, away from a power grid without the burden of installing more AC lines.  PoE opens up cabling and routes that are more efficient.  Plus, it improves network coverage further reducing cost.

Energy Consumption

While saving deployment costs is nice, reducing monthly overhead is even better. Power over Ethernet presents that opportunity. Managed Ethernet switches, such as the Antaira LMP-0800G, include Simple Network Management Protocol (SNMP) software that allows you to control power consumption. While SNMP is available on managed industrial networking devices, it gains effectiveness through PoE.  Specifically, the devices do not need individual AC to DC converters that consume extra power.

Signal Reliability

While this ties closely with design, PoE access often pushes network designers to create more reliable systems. While some of this is due to the convenience of being able to deploy more Ethernet cable, PoE can help signal reliability in two other important ways. First, it makes it easier to add Wi-Fi extenders where they are needed to boost overall coverage. Second, centrally managed PoE offers the option of putting entire networks or portions of networks on battery backups. Rather than just retaining broadcast during a power outage, PoE networks can use batteries and Uninterruptible Power Supplies (UPS) to keep endpoint devices connected to a central location.  Centrally located backup power reduces the total number of backups needed.

Disadvantages of PoE

Not all networks benefit from PoE enabled devices.   Special consideration needs to be given to VoIP, emergency backups and upgrades.

VoIP (Voice over IP)

Voice over IP or VoIP in and of itself is not inherently disadvantageous. It offers communication that may have greater clarity and reliability than traditional options.  It can transmit data and audio. These all sound like perks, but switching to VoIP can be more costly. VoIP devices consume more power than their traditional counterparts, and operating them through PoE can actually increase overall power costs.  A power audit can help determine if a switch to VoIP and PoE will save or cost money in the long run.

Battery Backups

Centralized battery backups are an enormously cost-effective way to improve reliability in smaller systems. For large facilities, backup generators are often a better choice. If your facility already makes use of a generator or other backup options, switching to batteries is likely an unnecessary expense.

Upgrade Costs

Staying up-to-date with technology is wonderful for productivity, but it’s a nightmare for budgets. PoE is properly standardized by IEEE, and you can rely on it for the foreseeable future.  But compared to traditional AC power grids, it will have a dynamic life span. If upgrading to PoE isn’t going to save you considerable money now, it will certainly cost even more in a few years when you upgrade to the next innovation. PoE often pays for itself, but it is important to consider future upgrades in your cost assessment.

Design Tips

The best networks are custom designed for efficiency and effectiveness.  So, there is a limit to what general advice can do for you. There are a few tips that may prove helpful for most networks.

Common Devices

The biggest consideration in designing around PoE are the endpoint devices. The most common are VoIP equipment and IP cameras. If you plan to use either, PoE Ethernet switches are going to save you time, money and headaches. Other devices frequently tied to PoE are Wi-Fi extenders, Bluetooth access points and RFID scanners. On a more specialized end, data acquisition and system monitoring tools can utilize PoE, too.

PoE vs PoE+

There are two IEEE standards for PoE. Standard Power Sourcing Equipment (PSE), specified in IEEE 802.3af, supplies a maximum power of 15.4 watts (W). Powered Devices (PD), which receive power, may consume up to 12.95W.  The difference of 2.45W being potentially dissipated along the cable.  PoE+ PSE devices, specified by IEEE 802.3at, provide 25.5W to powered devices.  These may consume up to 12.95W (type 1) or 25.5W (type 2).

In many cases, the choice between these formats will be made for you. Most  high-definition IP cameras, especially ones with a heater, will require the higher power output of PoE+.  The trade-off between PoE and PoE+ is straightforward. PoE networking tools cost less on average but have lower future capacities. In most cases, committing to PoE+ up front will give you better future proofing, and it will save on equipment upgrades down the road.

Learn more about PoE+ in our blog post, PoE, PoE+, and PoE++ Explained.

Cost Ratio

Finally, consider an important cost ratio: overhead savings vs installation costs. Ethernet lines are not as efficient as AC at long distances. This means the optimal power configuration could require additional devices to compensate for loss over distance. You can determine overall power efficiency by multiplying the efficiencies of the PSE, PD, number of ports and any extra circuitry.  The equipment manufacturers should list power efficiency ratings for their products. This figure gives you an indicator of how the PoE configuration would perform against traditional infrastructure, and it will determine how overhead costs will compare to the installation costs. This doesn’t factor quality of life metrics, such as improved productivity.  But, it’s a good start to determine how to build or expand your network.

Antaira PoE Ethernet Switches and Devices

Antaira Technologies’ broad line of industrial Ethernet switches, splitters and injectors offer reliable power, high-speed data transfer, environmental ruggedness, security and flexibility.  They are ideal for powering IP cameras, wireless bridges and clients, VoIP and alarms.  Choose features like PoE or PoE+ ports, unmanaged or managed, fiber connectivity, Fast or Gigabit speed and wide operating temperature.

Whether it’s a new project in an industrial or outdoor location or an addition to existing infrastructure, Westward Sales has the solution you need from trusted sources like Antaira.  Contact a knowledgeable representative to learn more.