How to Extender PoE Switch Max Transmit Distance?

As a device providing power and data transmission for network equipment, PoE switches have changed the traditional power supply and connection methods of network devices. By deploying PoE switches, power and data can be transmitted simultaneously through a single Ethernet cable, facilitating the deployment of many devices. However, it is well known that the transmission distance of Ethernet cables is limited. In the following text, we will discuss various methods for extending the PoE transmission distance so that you can maximize the range of the Ethernet power supply.

How to extend PoE distance?

As is well known, the maximum transmission distance of PoE is generally 100 meters. However, achieving this maximum distance requires considering multiple factors, including but not limited to PoE standards, cable quality, power supply voltage, and selecting switches with CCTV mode and VLAN. The limited transmission distance restricts the application range of PoE devices and increases deployment challenges. Nevertheless, there are still measures we can take to extend the transmission distance of PoE. Next, I will discuss how to achieve this goal.

Media Converter

A Media Converter is a type of network device that can convert different types of signals, such as converting electrical signals to optical signals, or optical signals to electrical signals. PoE switches can extend the transmission distance by connecting to a Media Converter. During signal transmission, the Media Converter functions as a relay, effectively extending the signal transmission distance. Since optical fiber has a longer transmission distance than copper cables, using a Media Converter to connect to optical fiber can achieve longer transmission distances. A PoE Media Converter can be chosen if power supply functionality is required simultaneously.

PoE Repeaters

PoE repeaters are commonly used with PoE switches and are typically employed to extend the transmission distance of PoE signals. Their primary function is to amplify and transmit signals, thereby extending the transmission range of signals within cables. It's important to note that PoE repeaters cannot infinitely extend the transmission distance, as signal attenuation occurs during transmission, and the quality of the cable also affects the transmission efficiency.

PoE Extender

PoE extenders are devices that effectively extend the transmission distance of PoE. They achieve distance extension by enhancing the network and power. However, while ensuring the transmission of signals and power, they consume some power to support their own operation, and only the remaining power is passed on to the next PoE device in the line. Of course, their power loss is controllable. Choosing higher-quality Ethernet cables can reduce power loss, thereby increasing the power delivered to the next device. By daisy-chaining multiple PoE extenders, the transmission distance can be extended to a maximum of 400 meters. Taking the IEEE 802.3at standard as an example, here is the relationship between available power and the number of PoE extenders:

Select PoE Switches With CCTV Mdoe or VLAN

The PoE switch with CCTV mode, once activated, injects a higher voltage power supply, enabling transmission over longer distances, up to a maximum of 250 meters. However, upon switching to CCTV mode, network speed drops to 10Mbps. Considering that the bandwidth requirements of most surveillance cameras are below 8Mbps, this mode fully meets usage demands. However, for networks requiring simultaneous access by multiple users, the 10Mbps bandwidth is evidently insufficient, making VLAN an indispensable feature. VLAN isolates PoE ports, allowing each port to communicate only with the upstream port, ensuring that each independent port has a bandwidth of 10Mbps without sharing bandwidth with other ports, thus meeting the access requirements of multiple users.

High Quality Ethernet Cable

The quality of Ethernet cables has a significant impact on transmission distance. During signal transmission, lower-quality Ethernet cables may suffer from poor conductivity due to the lower purity of their copper conductors. This can lead to signal attenuation, causing the signal to gradually weaken during transmission and potentially preventing it from reaching the expected distance, thereby resulting in signal loss or distortion. Additionally, lower-quality cables typically exhibit weaker resistance to interference, as they use inferior insulation materials. This makes the signal more susceptible to electromagnetic interference from other electronic devices, further compromising signal quality or causing transmission errors. Therefore, selecting high-quality Ethernet cables is crucial for ensuring the transmission distance of PoE switches.

Increase Supply Voltage

The supply voltage does indeed affect the transmission distance of PoE switches, with higher voltage helping to reduce signal attenuation in the cable. Since electrical signals are transmitted along with the power supply, higher voltage can provide more energy, stabilizing the electrical signal during transmission and reducing the impact of signal attenuation, thereby enabling longer-distance power transmission. PoE has three different power supply standards: IEEE 802.3af, IEEE 802.3at, and IEEE 802.3bt. IEEE 802.3af provides a maximum voltage of 48V, IEEE 802.3at provides a maximum of 57V, while IEEE 802.3bt provides a maximum of 60V or higher voltage. Therefore, devices with the 802.3bt power supply standard theoretically enable longer transmission distances.

Optimize Network Environment

The network environment indeed has a certain impact on the transmission distance of PoE switches. Since electrical signals are transmitted in copper cables, they can be affected by electromagnetic interference from other electronic devices, thereby affecting the transmission distance. Therefore, optimizing the network layout helps to improve the transmission distance. By optimizing the cabling and minimizing the number of electronic devices along the transmission path, electromagnetic interference can be reduced, thereby enhancing the transmission distance of PoE switches.

Conclusion

In summary, extending the transmission distance of PoE switches is crucial for maximizing the efficiency and versatility of network deployment. By utilizing technologies such as media converters, PoE repeaters, and PoE extenders, along with the option to choose PoE switches supporting CCTV mode and VLAN, purchasing high-quality Ethernet cables, and optimizing the network environment, users can overcome the limitations of standard transmission distances and achieve longer-distance power and data transmission. If you have any questions, please feel free to contact QSFPTEK's CCIE/HCIE engineers at [email protected].