Valmont Telecom | Valmont Site Pro 1, recently conducted a webinar titled “Small Cell: Key Developments & Design Considerations,” where the team covered critical issues facing small cell deployment in aesthetics, engineering, testing and speed to market.
Importance of Aesthetics
“Aesthetics are of particular importance when it comes to the success of small cell deployments,” said Luke Ferguson, National Application Sales Engineer. He noted that unsightly deployments in the past have led to pushback from municipalities. Carriers have numerous options today to deploy small cells that fit into the cityscape.
“In order for small cells to be sustainable, we all need to work together to make sure we’re doing what’s best not only for cell coverage, but also to maintain the city’s unique characteristics and historical look,” Ferguson said. “Between the various types of poles, luminaire arms, pole-top attachments, side shrouds, finishes and base cabinets, there are virtually endless options for small cell installations.”
The finish on the pole is a very important aspect of the aesthetics, according to the Valmont team, but it also impacts the life span of the pole. Valmont owns many galvanizing plants across the country. They stated, “All steel poles should be galvanized for longevity. Painting over galvanizing offers even more superior protection.”
Valmont has been manufacturing lighting and traffic equipment for at least 60 years and it is responsible for more than 51% of existing light poles in the United States, which helps the company to create small cell installations that match the existing light poles. The benefit of deploying external concealment poles, according to Valmont the team, is the flexibility that it allows a manufacturer to match a small cell’s appearance to existing poles.
According to Ferguson, “For external concealment, top shrouds are the primary concealment method used to hide antennas, although sidearms are also a possibility to install the antennas. The radio can be positioned below the antenna or in a side shroud or in the base.”
For internal concealments, poles are limited to round straight poles, with 12 and three-quarter inch and 18-inch diameters, but there are options in terms of the top shrouds, including single-carrier 4G/5G, dual-carrier 4G/5G and triple-carrier 4G/5G.
Engineering Best Practices
Valmont’s pole-top attachment can attach to existing steel or concrete structures, but most steel light poles don’t have adequate strength for additional small cell loading. “It is possible to order a new pole while utilizing the existing foundation,” he said. “But it’s important to ensure that the foundation has the necessary strength and the final loading configuration.”
In one case, Valmont built a small cell with a foundation that was able to support the 4G attachments as originally requested. But when, a year later, the customer wanted additional 5G attachments, the foundation was inadequate to handle the 4G/5G loading and had to be ripped out and upgraded. “It’s important to make sure that whatever you’re constructing can support the final configuration that you expect the small cell pole and base to support,” the Valmont team said.
The shape of the pole plays a role in whether they will be susceptible to fatigue over time, because some are more likely to experience harmonic oscillation. “Square-shaped poles perform the worst [in wind testing], followed by round, straight poles,” the team said. “Round tapered poles perform the best, so it may be good to choose a taper pole if it is going to be installed in a highly exposed area.”
The foundation design for the small cell will be most accurate if soil information is provided to the designer, according to the Valmont team. “If no soil information is provided, the designer will assume Class four soil, which is close to a worst-case analysis. If there are many sites being installed, it is possible to save a lot of time and money on the foundations by using more accurate soil information.”
Top shrouds, side shrouds and base cabinets have different characteristics when it comes to potential thermal issues. Larger shrouds perform better thermally as the additional space allows the heat to dissipate. To verify the thermal performance of shrouds, Valmont runs computational fluid dynamics computations, which show how the heat dissipates, to ensure the equipment does not overheat.
Testing for the Real World
Valmont has recently received Telcordia GR 487 and UL approval, after multiple tests were completed in early 2021. Telcordia GR 487 governs electronic equipment cabinets, and UL safety certification deals with products’ safety and sustainability. Among the products tested were 14-inch, 16-inch and 22-inch 4G/5G top shrouds; 12 and three-quarter-inch and 15-inch integrated shafts; as well as the 20-inch round and 26-inch square base cabinets.
According to the Valmont team, “Together, these approvals help ensure our small cell equipment does not pose a fire or safety threat during the installation and sustained operation of the product throughout its lifespan.”
An acoustical noise test was performed that measured maximum noise level from the small cell fans. At 100% capacity, the fans produced 65 decibels, which is equal to a normal conversation. When operated at a normal speed of only 25% of capacity, the sound was 50 decibels, similar to the sound level of a quiet office. “The fan sound is an important factor because, it can really easily draw attention to a small cell if the fans are excessively loud,” the team explained.
The equipment was also tested to see how it would perform when exposed to high levels of heat. It was placed in a chamber with an extreme ambient temperature with lights imitating full solar heat on all sides. This essentially simulates the hottest conditions a small cell is expected to experience. The passing maximum internal equipment temperature of 131 degrees Fahrenheit ensures that the equipment will not fail due to excessive heat even under the worst-case conditions. Impact resistance was tested by dropping a 16-pound bowling ball from 6.2 feet above on the equipment. Corrosion resistance was also tested.
Speed to Market
Speed to deployment is one of the most critical factors facing the future of small cells, they explained. The process of designing and deploying small cells must be streamlined to meet the buildout needs of the wireless industry that are projected for the future, they said, and to improve speed to deployment, “it is best to involve Valmont early on in the design process.”
“Sometimes the engineering firms create conceptual drawings that are approved without our input,” the team said. “These conceptual drawings are sometimes drawn without any real-world knowledge of how these systems work. These can potentially cause us to create an entirely new design when an off-the-shelf design may have been possible from the beginning.”
For more information on Site Pro 1, click here. To view the previous webinar, request access by signing up for an account and access the event on the Site Pro dashboard.
By J. Sharpe Smith Inside Towers Technology Editor
Reader Interactions