Value Engineering the Design
It’s not unusual to receive a design for an Auxiliary Radio Communication System (ARCS) or Emergency Responder Radio Communications System (ERRC) that goes out to bid that will never work. The design is often provided to the client for free and created in a quick and dirty fashion. In the industry, this is called a “level-setting” bid design; in other words, it’s deficient. When we receive these types of designs, our RF Engineers use iBwave, a propagation tool that simulates how an in-building wireless system functions. The tool allows us to evaluate a design and optimize the in-building system, which rarely matches the level-setting plans.
It’s Like Using a Mack Truck Engine in a Volkswagen
It’s okay to use level-setting bids because plainly, you have to start somewhere. The trouble begins when there are assumptions that these plans will work. ARC and ERRC systems aren’t used to provide better cell service for business; they are used to save lives in a high-rise fire. Low-balling the design is not where a building owner wants to cut costs. Often, when insufficient models win the bid and are installed, they don’t provide full coverage. To overcompensate, the engineers may “turn up the volume” of the radio frequency in the building, hoping to fix the problem. This modification is like using the engine of a Mack truck in a Volkswagen, and it causes radio spectrum pollution.
Turning Up the Volume = Radio Spectrum Pollution
As an example, we were recently asked to submit a bid for an ARC system for an eight-story 30,000 square foot building with a roof and bulkhead in New York City. The proposed design presented in the submission utilized a one-riser solution with four antennas that would never work as planned. In order to propagate through multiple levels of obstruction, the antennas would have to be overpowered. This adjustment would inadvertently cause the signal to propagate outside the building (radio spectrum pollution), which is not permitted. RF Solutions’ enhanced design utilized an additional vertical riser, and more antennas at specific locations to control the Effective Isotropic Radiated Power (EIRP), thus retaining the propagation inside the building while maintaining adequate coverage.
A Better Design is Also Cost-Efficient
Our design saves money, is more efficient, and easier to install because using two vertical risers within 2-hour fire-rated stairways allows us to eliminate horizontal cable runs through non-fire-rated pathways that would then have to be upgraded to provide 2-hour fire resistance. The cost for labor and materials for such fire rating is many times the cost of the additional materials and installation required to implement our design.
iBwave-Trained Engineers Produce Robust Wireless Designs
Propagation tools like iBwave are just that, tools. They are absolutely necessary, but they are also only as good as the user. Christophe Volckaert, a Manager of Customer Care for iBwave, says, “While iBwave Design is a powerful software that helps RF engineers design the best wireless networks, they can quickly become complex. With this in mind, we developed our certification program to enable engineers to get the most out of features available in iBwave Design. We believe well-trained engineers are more efficient at producing robust wireless designs that meet carriers’ KPIs.” In addition to iBwave training and certification, an effective engineer must have experience with in-building design and construction/installation standards and processes, something that all our engineers at RF Solutions possess.