By Antoine Pelletier, Project Engineer, Intertek
It is great to be given the opportunity to write in the IAEI magazine again. In my first article in the January/February 2022 edition, I wrote about Power Over Ethernet (PoE) and its standardization ecosystem. This previous article revolved around the “traditional” PoE delivery over four (4) twisted pair of copper conductors and understood to be deployed within 100-meter reach. While the power delivery at the device kept increasing from 12.95W in the first PoE Standard IEEE 802.3af (2003) to 51-71W in the newer IEEE 802.3bt (2018), its nominal length remained unchanged at 100 meters.
As technology evolves and new use cases emerge, the cabling infrastructure that supports those continues to modernize itself. Consequently, the cabling infrastructure is subject to newer deployment schemes that allow for power and data delivery that exceed the historical 100-meter barrier such as:
- Extended distance using 4-pair cabling
- Single-Pair Ethernet (SPE)
- Fault Managed Power (FMP)
The first method (extended distance using 4-pair cabling) consists of deploying 4-pair communication cables beyond the 100 meters limit. While Ethernet technology over 4-pair cabling (BASE-T) and the corresponding PoE Types 1 to 4 were standardized based on the nominal 100-meter length, the technology may be deployed at longer lengths and still fulfil its intended use. In some use cases, the device (access control, camera or such) is slightly beyond the 100-meter reach and it can very well be that the device will function perfectly at that extended reach. These are some things to keep in mind in those deployments.
- Always follow proper engineering guidelines and manufacturer’s recommendations. Several cabling companies conducted extensive studies of their cabling solutions and produced technical reports that recommend installation boundaries based on applications being used.
- Check your use cases. What type of load or device is connected to the circuit?
- Larger conductors may be used (ex: 22 AWG). Their higher copper cross-sectional area allows for lower signal attenuation and DC resistance. Cables made with larger conductors also help prevent heat generation.
- Independent third-party testing can support such claims.
The Single-Pair Ethernet technologies are an alternative way to deliver power and data over copper cabling. While they are more limited in data rate (Mbps) and power delivery (W), this technology can largely extend beyond the length reach up to an amazing 1,000 meters per the 10BASE-T1L protocol that can operate data rate up to 10 Mbps. In the single-pair ethernet “world” the PoE is referred to as PoDL, which stands for Power Over Data Lines. Several power classes exist for power delivery allowing for 0.5 to 52W at the device. Although the power delivery is less than the traditional POE technology, it can be sufficient to support various building automation use cases such as sensors, valves, etc. Cable used for SPE may be of a very wide conductor size between 14 AWG to 26 AWG, with bigger conductors being favored for longer distance.
Finally, Fault Managed Power may also be used to deliver data and power at extended distances. Although FMP is not intrinsically designed to deliver high speed data, the technology can be used in conjunction with fiber optics communications to reach longer distance. In this case, a hybrid copper and fiber cable may be used to deliver data and power to distant enclosures. Then the power and data can be transferred over traditional 4-pair and fed into devices located in closer proximity to the enclosure (cameras, wireless access points, IP phones and more). This deployment method avoids the need to use conduits between the telecommunication room and the enclosure thus resulting in labor and material savings.
As we have various technologies and options, it should be considered on a case-by-case basis which technology best suits projects as they all provide different benefits. In some projects, multiple technologies may also coexist. As always, safety listed products must be used as directed by code and AHJs. The communication cabling infrastructure may need to carry CMP, CMR or such listings and the optional -LP rating comes into play for support of remote powering. The FMP cabling infrastructure may need to carry one of the newer CL4R, CL4P or CL4Z designations of UL 1400-2 including the -FMP current rating for cables 18 AWG and smaller conductors. Furthermore, these technologies also continue to evolve in our ever-changing world. These IEEE task forces are working on upcoming standards targeted to be published in 2026:
- IEEE 802.3da for enhanced multidrop will allow for 10Mbps delivery up to at least 16 nodes up to 50 meters
- IEEE 802.3dg for long-reach single-pair will allow for 100Mbps up to 500 meters and some amount of power
In conclusion, as technology continues to advance, choosing the right cabling infrastructure for power and data delivery depends on specific project needs, with options such as extended distance 4-pair cabling, Single-Pair Ethernet, and Fault Managed Power offering diverse solutions that meet evolving industry standards.