ConcealFab is a design and manufacturing arm of Valmont Telecom, known for their infrastructure products focused on faster site approval and improved wireless network performance. The brand’s products include infrastructure mounting, interference mitigation and concealment options for 4G and 5G deployments. Now, ConcealFab is ensuring its customers avoid major fines, safety lapses and PIM issues related to RF.
The FCC requires signage near antennas to warn people of potentially unsafe RF exposure. “RF warning or alerting signs should be used to provide information on the presence of RF radiation or to control exposure to RF radiation in a given area,” according the FCC’s policy on RF warning signs. Appropriate signs should also incorporate the format recommended by the Institute for Electrical and Electronics Engineers (IEEE).
Most commonly, on rooftops, RF signage is deployed on standard traffic cones like roadway construction zone signs, which are often blown over by the wind. In testing, a single traffic safety cone tipped over when subjected to 78.2 MPH winds, and three chained traffic safety cones blew over when just 37.7 MPH was applied.
“Typically, RF warning signage has not been designed to stand up to any sort of significant wind,” said Jonathan Morris, Director, Interference Product Line at ConcealFab. “And if you go on a rooftop, you will commonly see a lot of these sign stands just lying down, not fulfilling the FCC requirements.”
Metal signage alternatives were designed to solve this problem, counteracting the force of the wind, and some will secure the RF sign with bailing wire. But these efforts are prone to generating passive intermodulation (PIM) items at the site.
“There are other options including video monitoring to see if the sign stands have fallen over, or even pressure sensors. Either way, someone, typically a general contractor, is responsible for continuously standing it back up,” Morris explained. “These are all expensive and labor-intensive solutions. They also may generate PIM – another issue.”
If not appropriately handled, large fines may be the ultimate outcome. In 2015, two carriers were fined a total of $85,000 for providing insufficient protections to prevent public access to their antennas that were co-located on a rooftop.
ConcealFab has created a remedy leveraging locally sourced cement blocks for the foundation that will withstand up to 190 MPH winds. The sign itself is made completely out of plastic, so there isn’t any possibility of PIM generation.
The ConcealFab RF Safety Sign will be available in August 2024. According to Morris, carriers have already expressed interest in replacing the signs on their current sites. “I was on a national call with engineers from one of the top tier carriers, and they are excited about this product,” Morris said.
For more information on the RF Safety Sign, email ConcealFab at this [email protected].
By J. Sharpe Smith, Inside Towers Technology Editor
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