September 1, 2016 —
Entwined with cables, wireless infrastructure accelerates the economic flywheels that launch nations into rising prosperity. Magical as it is, wireless works because core services and the most remote parts of the radio access network are correctly wired and cabled, and properly connected. Cables are essential to profitability in the wireless business.
Richard Byrne, CEO of the prolific developer TowerCo, accurately observed that Americans formerly embraced the utility infrastructure necessary to deliver critical communications services. To illustrate Byrne’s point, you need only a brief Web search.
Year by year, engineers and tradesmen put technology to work to create critical infrastructure. That effort benefits society and contributes to the profits necessary for companies to sustain service delivery to consumers. Since Roman times, humankind understood how to create the infrastructure necessary to transport water great distances. Remnants of Roman aqueducts still adorn hills and span valley areas. More recently, technology development permitted water transport through piping infrastructure hidden beneath streets and inside walls. In fact, most utility infrastructure is hidden. We have not figured out a way to make traffic control signals invisible, and for good reason: It’s unsafe when drivers are unable see the light turn red. In addition, we have not figured out a way to make wireless infrastructure invisible, because if your cellphone is unable to see the signal from the critical infrastructure necessary for wireless connections, there is no communication.
Making wireless infrastructure even more unobtrusive stretches available technology to the limit. Utility infrastructure development teams at companies such as TowerCo do the best that can be done to satisfy authorities in various jurisdictions while providing what mobile network operators need at pricing that permits sustainable business models.
Wires for Wireless
Dale Carey, CEO at Eco-Site, in prior service coined the statement, “It takes wires to go wireless.” Fifteen years ago, Dale recognized the effect that phrase had with financiers and used it in the right way in front of the right people to build support for the fledgling wireless communications business. Now, when the industry needs to create critical infrastructure to support ever-faster, always better mobile connections, too many cities are reluctant to tolerate the cables that are inexorably part of the critical infrastructure that powers wireless communications.
Conversations with communities about the need for a practical balance between function and invisibility must continue. While we all wait for the conversations to mature, towers and small cells with today’s technologies keep developers fully engaged.
Is It a Wire, or Is It a cable?
Tradesmen are aware of the many differences that distinguish wire from cable. Dictionary definitions for wire mention one or more threads of metal involved with conducting electricity. Looking at an image of a rope-like thing supported pole to pole, the interpretation could be a wire, a cable or a combination of both. In the fixed infrastructure side of telecommunications, semantics are more often satisfied with reference to those rope-like things as cable.
For cable and connectors, project managers can find tower techs who know how to do it right. Dozens of details are important. Two important ones for tower technicians are: leave no flecks in the foam, and don’t bend the cable too tightly.
“No flecks in the foam” relates to on-site connector installation on custom-length, foam dielectric coaxial cable. MetroPCS engineers are credited with being the first to place a high priority on the RF transparency of coaxial cable installed between transceivers and tower-mounted antennas. Shortly thereafter, Verizon specifications challenged line and antenna crews to deliver assemblies with lower passive intermodulation (PIM) interference. Techs who knew that a loose nut at the antenna would help to deliver a clean sweep on the spectrum analyzer soon learned that same loose nut, bad for transparency, sore-thumbed a PIM test. With those experiences to draw upon, today’s top tower techs learn how to install a 7/16 DIN or type N connector on the coax without leaving any little flecks of metal on the surface of the cut foam.
“Don’t bend it too tight” is good advice for coax, even more so for fiber-optic cable. Fiber-optic cables bundle together slender filaments of glass. Each filament is coated with multiple layers of reflective, protective material similar to dried superglue. These filaments or strands of glass fiber are most efficient in conducting light when the strand is so slender and so skinny that light rays can travel along the strand in only one path. That path is named the “mode.” One path is single-mode — straight through the fiber without being so wide a strand that the rays of light zigzag across the diameter of the glass. Thus, single-mode fiber is the common denominator for cabling LTE and the soon-to-be 5G cellular networks. Cables containing fiber-optic strands can deliver highly reliable results for a long time when handled and installed with a bend radius no tighter than two inches. Think about the bend around a softball or a medium-sized grapefruit — that is about as tight as the cable should be bent. When expert techs are working with single strands in fiber patch panels, different rules apply, but for outside plant construction, only gentle bends should be applied. If the cable is bent too tightly, constricted by wire ties, compressed by U-clamps or stapled to a piece of wood, the strands inside the cable suffer microfractures. Light leaks out of the microfractures, signal transparency suffers, and systems do not perform as designed.