Emergency Communications Systems Get the Critical Power Back-up Now Mandated

The ability to communicate with anyone at any time is a privilege not to be taken lightly – especially when it comes to emergency events. Here, quick and accurate information exchanges can mean the difference between life and death with communication interruptions acknowledged as a major factor in first responder injuries and fatalities. This has led to the development of innovative solutions that maintain the continuity of communication protocols for emergency response systems. Perhaps the biggest catalyst for change came in the wake of the September 11th tragedy that forever changed how emergency communications systems are planned, implemented and operated.

Many factors contributed to the communications failures experienced during 9/11. The building wiring infrastructure and phone lines were compromised, and the overall construction of steel and concrete inside the building negatively impacted radio signals. This combination of factors vastly limited FDNY’s ability to communicate directly with each other and additional first responder departments, as well as the Fire Command Center located in the lobby of the North Tower. In the end, the overall emergency response was severely hampered.


The communication shortfalls experienced that day were well publicized and even documented in the 9/11 Commission report that cited, “internal communications breakdowns resulting from the limited capabilities of radios in the high-rise environment of the World Trade Center.” As a result of these events, in-building requirements for emergency communications were mandated across New York City, making the Fire Department of the City of New York (FDNY) the first authority having jurisdiction (AHJ) to enforce the application of auxiliary radio communication system (ARCS).

Sections 403.4.4 and 907.2.13.2 introduced in the 2014 NYC Building Code requires all buildings exceeding 75 feet to install an ARCS, a mandate that effectively paved the way for the adoption of local addendums and policy changes that are now observed throughout the country.

Understanding Emergency Response Systems

ARCS are a type of emergency responder communications enhancement system (ERCES) specific to New York City. Unlike conventional ERCES, an ARCS provides radio channels specifically for onsite command and control without linking back to a dispatcher. Upon arriving at the emergency location, FDNY manually activates an ARCS to amplify signals from firefighters’ portable radios throughout the interior of the building to best support teams of firefighters operating simultaneously inside the facility.

Both bidirectional and wireless, ARCS utilizes exclusive FDNY radio frequencies to prevent interference. These systems consist of a head-end radio amplification unit (RAU), antenna system, power supply, and a dedicated radio console (DRC), or base station. The idea is that with the base station in the lobby and the antenna system encompassing the entire building, fire fighters experience uninterrupted communications during emergency events.

Without an ARCS in place, standard 700/800 MHz or UHF/VHF radio frequencies cannot easily penetrate the multiple layers of building materials found in high-rises, especially in stairwells, elevator shafts and basements. Conversely, the carefully deployed antenna system provided by an ARCS allows radio signals to permeate throughout the building’s interior. When used alongside land mobile radios (LMRs), this ensures communications can be transmitted and received by emergency fire responders, regardless of if they are on the first floor or the one-hundredth.

ARCS’ basic components typically include dedicated radio consoles (DRC), radio amplification units (RAU), a bi-directional amplifier (BDA), distributed antenna system (DAS), radiating cables, and battery backup unit (BBU). The BDA acts as a signal booster, amplifying and extending the reach of radio signals, while the DAS utilizes a network of antennas to receive and distribute wireless signals throughout the building’s interior. BBUs then ensure uninterrupted functionality of ERECS during power outages.

Ensuring Continuous Emergency Communications

Without reliable power, ARCS cannot perform its intended purpose of providing uninterrupted communication channels inside a structure in crisis. New power backup products play an essential role in assuring seamless operation of emergency communications systems, ensuring uninterrupted power for BDAs and other critical components. Such devices serve to enhance the stability and reliability of ARCS by providing ample back-up power when needed. Advanced power and backup solutions also incorporate all the necessary supervisory notifications that can be remotely monitored with annunciator panels.

 These annunciator panels are essential components of ARCS solution for monitoring emergency back-up power. Equipped with multiple independent supervisory outputs, modern annunciator panels enable remote status and trouble condition reporting directly to the fire alarm control panel for early intervention. This ensures that public safety communications systems are receiving the backup support they need during a power outage – which is a common occurrence during natural disasters and other emergency scenarios.

Specific UL Listings

Today, the design, installation, testing and maintenance of ERCES/ARCS components are covered by NFPA 1225 standard for Emergency Services Communications. This code is enforced by AHJs and may also be supported by local addendums and standards, including the recently released UL 2524 standard for in-building emergency responder communications systems.

UL 2524 is a standard proposed by Underwriters Laboratories for in-building, two-way ERCES and ARCS components such as repeaters, transmitters, receivers, signal booster components, remote annunciators, operational consoles, power supplies, and battery charging system components. UL 2524 is a requirement for buildings to receive their certificate of occupancy with the IFC 2021 and NFPA 1225 code versions. A UL 2524 listing also signifies compliance with the highest level of industry standards to guarantee seamless communications among emergency responders within and around commercial buildings.

The Importance of Emergency Communications Everywhere

The mandates for ERCES and ARCS in buildings are designed to save lives - not only individuals within a building that’s in distress, but also first responders tasked with saving occupants. What’s more, in-building radio communications have not always been reliable due to a structure’s construction and materials, unforeseen emergency situations, and natural disasters.

For example, in the aftermath of Hurricane Katrina in 2005, more than 3 million telephone landlines were rendered inoperable, severely hindering emergency communications. And in 2020 alone, the United States experienced 22 different billion-dollar disasters, inflicting extensive damage to infrastructure and communication systems. Resilient emergency communications play a vital role in preserving and protecting critical infrastructure across a wide range of sectors including energy, transportation, water supply, and telecommunications. Ensuring ERCES and ARCS are in place and always operational is a paramount task to sustain critical infrastructure operations.

In short, first responder emergency communications systems provide the ability to always remain in continuous communications during crises in commercial, public, and critical infrastructure facilities. Hence the need for reliable UL 2524 listed power and back-up solutions for BDAs and other critical ERCES/ARCS system components is not only a top priority, it’s also now a mandated one.



Paul Rizzuto

Paul Rizzuto

Director of Technical Services and Support

Altronix Corporation



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