For those who need to provide cellular and/or public safety systems inside their facilities, many manufacturers still rely on single-mode fiber for the signal transport via analog RF over glass (RFoG) technology.
Many of these devices require hundreds to thousands of watts of power, and in many cases this power has to be run hundreds or thousands of feet back to the main distribution frame (MDF) rooms or headends, due to centralized power backup requirements.
These and other high-power devices such as the TVs, lighting systems, and distributed PoE switches outlined above cannot rely on even the best UTP or PoE systems planned today.
When looking at the possible pathway congestion and distance limitations the proliferation of PoE devices foretell, even the latest solutions are limited to 100 watts over 90 meters.
Thankfully, we are seeing new technologies as well as evolutions of existing well-known technology rising to fill the gaps. The NEC seems to agree with the need for new or emerging technology, as the producers of the NEC have started to pay more attention to network powering.
While Sections 725 and 830 both cover some “types” of powering, the codes are playing catch-up with the latest devices. Recently, the NEC has taken notice of the levels of power being transported over the relatively small wire gauge typically used in Category 6A and other UTP/FTP cables.
A very healthy, and sometimes confusing, debate has ensued, adding to the uncertainty around the newer standard. One alternative to address the limitations of PoE is Class 2 power, which can service longer distances than traditional PoE.
The power level is still less than 100 watts, but the lack of requirement to use Category UTP cable gives designers more flexibility with respect to distance via larger-gauge conductors. If we pair the bandwidth and distance capabilities of single-mode fiber with the ability to use larger-gauge copper conductors, we can far exceed the 90-meter limitations of even the best PoE.
