As businesses add more connected technology, the network is responsible for much more than simply providing internet access. Wireless access points, security cameras, VoIP phones, access control devices, sensors, and other equipment may all depend on the same network infrastructure.
In simple terms, PoE supports lower-power devices, PoE+ provides more power for equipment such as advanced cameras and wireless access points, and PoE++ supports today’s most power-demanding network devices.
Power over Ethernet (PoE) can simplify these installations by allowing a single Ethernet cable to carry both data and electrical power to compatible devices. This can reduce the need for separate electrical outlets and power adapters while giving businesses more flexibility in where network-connected devices are installed.
However, not all PoE is the same.
The three terms businesses are most likely to encounter are PoE, PoE+, and PoE++. Each supports a different amount of power, and choosing the wrong standard can prevent equipment from operating correctly or limit its functionality.
Understanding the differences can help businesses make better decisions when upgrading their network or installing new technology.
What Is Power over Ethernet (PoE)?
Power over Ethernet allows compatible network switches or other power-sourcing equipment to send power and data through the same Ethernet connection.
Without PoE, a device such as a security camera might require:
- An Ethernet cable for network connectivity
- A nearby electrical outlet
- A separate power adapter
With PoE, a compatible Ethernet connection can handle both power and network connectivity.
This is especially useful for equipment installed in locations where traditional electrical outlets may be inconvenient, such as ceilings, exterior walls, hallways, warehouses, and other hard-to-reach areas.
Common PoE-powered devices include IP security cameras, wireless access points, VoIP phones, access control equipment, sensors, and other smart building devices.
PoE vs. PoE+ vs. PoE++ at a Glance
The biggest difference between the standards is the amount of power they can provide.
| Standard | IEEE Standard | Type | Maximum Power From Source | Common Applications |
|---|---|---|---|---|
| PoE | 802.3af | Type 1 | 15.4W | VoIP phones, basic cameras, low-power devices |
| PoE+ | 802.3at | Type 2 | 30W | Wireless access points, advanced cameras, other higher-power devices |
| PoE++ | 802.3bt | Type 3 | 60W | PTZ cameras, higher-performance APs and other higher-power equipment |
| PoE++ | 802.3bt | Type 4 | 90W | High-power network and smart-building devices |
The maximum power available to the device itself is lower because some power is lost between the power source and the powered device. For example, IEEE Type 4 can supply up to 90W from the source, with roughly 71W available to the powered device under the standard.
What Is Standard PoE (802.3af)?
The original IEEE 802.3af PoE standard provides up to 15.4 watts per port at the power source.
For relatively simple network devices, that can be plenty.
Standard PoE may be appropriate for equipment such as basic VoIP phones, certain IP cameras, and other low-power network devices.
The limitation is that modern business technology has become increasingly power-hungry. More advanced cameras and wireless equipment can require more power than standard PoE provides.
That’s where PoE+ comes in.
What Is PoE+ (802.3at)?
PoE+, or IEEE 802.3at, increases the maximum power at the source to 30 watts per port.
That additional capacity makes PoE+ useful for a wider variety of business devices.
For example, newer wireless access points may require more power to operate all of their capabilities. Cisco documents examples of access points that can operate on standard PoE but with reduced functionality, while receiving full functionality when supplied with a higher PoE standard.
This illustrates an important point:
A device turning on doesn’t necessarily mean it is receiving the optimal amount of power.
A device connected to an underpowered port may operate in a reduced mode, depending on the equipment.
What Is PoE++ (802.3bt)?
As connected devices became even more capable, their power requirements continued to increase.
IEEE 802.3bt, commonly associated with PoE++ or 4-pair PoE, expanded the amount of power Ethernet infrastructure can deliver.
There are two primary levels:
Type 3: up to 60W from the power source
Type 4: up to 90W from the power source
Unlike earlier PoE standards that supply power using two twisted pairs, higher-power 802.3bt implementations can use all four pairs of the Ethernet cable to deliver additional power.
This makes PoE++ suitable for increasingly sophisticated devices, including certain high-powered wireless access points, PTZ surveillance cameras, smart-building equipment, displays, and other devices with greater power requirements.
Why PoE Matters for Security Cameras
Security cameras are a perfect example of why businesses need to consider PoE requirements before purchasing network equipment.
A basic fixed IP camera may have relatively modest power requirements.
A more sophisticated camera could include:
- Pan-tilt-zoom (PTZ) functionality
- Infrared illumination
- Heaters or environmental controls
- Advanced processing
- Higher-powered components
Those features can increase power requirements significantly.
Higher-powered PTZ cameras are a good example of why network infrastructure and power requirements need to be considered together. Bailey Systems recently deployed advanced PTZ cameras as part of the Pathway Homes video surveillance project, demonstrating how the network infrastructure behind a surveillance system is just as important as the cameras themselves.
If the switch supplying the camera cannot provide enough power, the camera may not operate as intended.
This is why surveillance projects shouldn’t be planned by looking only at the cameras. The switches, Ethernet cabling, network capacity, power requirements, and overall infrastructure supporting those cameras matter too.
What About Business Wi-Fi?
The same issue applies to wireless infrastructure.
Modern wireless access points can have considerably different power requirements depending on their capabilities. Some equipment may technically operate when connected to a lower PoE standard while disabling certain features or reducing performance.
For example, Cisco documents access points that operate with reduced radio capabilities when supplied through 802.3af compared with higher-power standards.
When businesses upgrade their Wi-Fi, it’s therefore important to determine whether the existing switches can adequately power the new access points.
Simply replacing the access points without evaluating the infrastructure behind them can create unnecessary limitations.
Don’t Forget the Switch’s Total PoE Budget
There’s another specification businesses often overlook:
The switch’s total PoE power budget.
Having 24 PoE+ ports does not necessarily mean a switch can provide the maximum wattage to all 24 ports simultaneously.
Switches have a total amount of power available for PoE devices, and that budget varies considerably between models. Current Cisco business switches, for example, offer different total PoE budgets even among models with the same number of ports.
Imagine connecting:
10 security cameras
6 wireless access points
8 VoIP phones
The business needs to consider both the requirements of each individual device and the combined power requirement of everything connected to the switch.
This becomes particularly important when expanding an existing network.
Is PoE++ Always Better?
Not necessarily.
Buying the highest-powered equipment available isn’t automatically the best network design.
The right choice depends on:
What devices are being powered?
A VoIP phone and a high-powered PTZ camera have very different requirements.
What does the equipment manufacturer require?
Device specifications should determine the required PoE standard.
How many devices will be connected?
The switch must have enough total PoE capacity.
What cabling is installed?
Higher-power PoE makes choosing the right Ethernet cabling increasingly important, particularly when cables are bundled.
What will the business need in the future?
A network designed only for today’s equipment may require another upgrade when cameras, wireless access points, or other devices are replaced.
The goal isn’t necessarily to install the most powerful option. It’s to build infrastructure that meets current requirements while providing reasonable room for future growth.
Build a Network That Supports Your Technology
From wireless networks and structured cabling to security cameras and access control systems, today’s business technology increasingly depends on the infrastructure behind it.
Bailey Systems can help businesses evaluate, design, install, and support the network infrastructure required for today’s connected devices.
Whether you’re upgrading existing equipment, expanding your network, or planning a new technology deployment, our team can help ensure your infrastructure is designed to support both your current requirements and future growth.
Contact Bailey Systems to discuss your network and infrastructure needs.
