Emergency Responders (Fire, Police, Medical) need to have clear radio communication when they are responding to emergencies inside commercial and municipal buildings. The US-based National Fire Protection Association (NFPA) has developed a code of standards to address this and related issues. This code is known as NFPA 72, the National Fire Alarm and Signaling Code and was adopted by Washington State on July 1, 2016.

NFPA 72 lays out the radio (RF) reception requirements for Emergency Responders, and specifies various technical standards for the communications equipment needed to meet those requirements. The code states that all new and existing commercial buildings meet the following minimum requirements for in-building RF reception for Emergency Communications:

Coverage Standards:

Critical Areas – 99% coverage. This includes fire command centers, fire pump rooms, exit stairs, exit passageways, elevator lobbies, standpipe cabinets, sprinkler sectional valve locations and any other areas deemed critical by the AHJ.

General Areas – 90% coverage.

RF Coverage Testing and Solutions by NW Communications:

NFPA 72 specifies making a 20-space test grid of each floor of the building, like that below:

Using this test grid, our certified technicians then thoroughly test each grid space for radio reception using specialized equipment. Each grid space is then marked as a pass or a fail. Depending on the final results, NW Communications will offer you the best and most economical solution for your building.

Due in part to modern LEED building standards, most buildings will need either an active or a passive Distributed Antenna System (DAS) for all grid spaces to pass. An active DAS system needs external power, while a passive system does not.

An active DAS consists of a donor antenna outside the building connected by cable to a BDA (Bi-Directional Amplifier, also known as a Signal Booster) inside the building, which then feeds the amplified signal to the antenna array inside the building. Additionally, the BDA is required to have Battery Backup with specific technical features.

Here is an example of an active DAS:

A passive DAS, on the other hand, does not require a BDA. A passive DAS consists of inside and outside antennas, and carefully engineered passive components in-between them. A passive system is not always a possible solution, but when it is, it offers a solution that needs no power and little maintenance, and is usually more economical than an active DAS.

Passive DAS systems are a NW Communications specialty. Many communications companies do not even offer them, as they have a slim profit margin. NW Communications is proud to offer these clever systems when applicable, as they are far more environmentally and economically friendly overall than active DAS systems.