One challenge to the design and installation of an Emergency Responder Radio Communication System (ERRCS) is that the process and codes required to implement vary by jurisdiction. This is one of the fundamental differences between an ERRCS and a Cellular Distributed Antenna System (DAS).  Despite this, there are some standard process and components  shared by all ERRCS. We’ve included them below with our apologies to the folks in the business for whom this is well-known.

From a process standpoint, there are a number of steps that are common to all projects.

1. Preliminary Assessment

    • Site Survey: Conduct a comprehensive survey of the building to assess the existing radio signal strength, identify dead zones, and understand the building’s layout and construction materials that may affect radio signal propagation.
    • Local Codes and Requirements: Review and understand local fire codes, NFPA (National Fire Protection Association) standards, and FCC (Federal Communications Commission) regulations that govern ERRCS installations.

2. System Design

    • ERRCS Code: If possible, contact the Authority Having Jurisdiction (AHJ) to determine if he/she has a written ERRCS requirements document.
    • Frequency Band Support: Design the system to support the frequency bands used by the local emergency services, including police, fire, and EMS per the AHJ.
    • Distributed Antenna System (DAS): A network of antennas distributed throughout the building to ensure uniform signal coverage. The DAS must be designed to cover all areas, including stairwells, elevators, basements, and other hard-to-reach places. Typically 99% of critical areas need coverage; 95% of all others- but again, consult the AHJ specification.
    • Bi-Directional Amplifiers (BDAs): Amplifiers that boost radio signals to and from the emergency responder’s radios. The selection of BDAs will depend on the building’s size and the specific signal enhancement needs identified during the preliminary assessment. There are a number of BDA manufacturers. See the Safer Buildings Coalition ( for details.
    • Signal Source: Determine the source of the signal that will be amplified throughout the building. This could be a direct feed from a local public safety radio system or a usually a donor antenna placed in a location with good reception of the public safety signals.
    • Battery Backup: Ensure the system has a robust battery backup capable of powering the ERRCS for a duration specified by local codes, typically 12 to 24 hours, to ensure operability during power outages.

3. Installation

    • Cabling: Install coaxial or fiber optic cables to connect the antennas to the BDAs and the signal source. The choice between coaxial and fiber optic cables will depend on the system design, building layout, and signal loss considerations.
    • Antenna Placement: Install antennas in locations determined during the design phase to ensure optimal coverage. The installation must avoid physical and electrical interference that could degrade system performance.
    • BDA Installation: Install the BDAs in locations where they can effectively amplify the signal without causing interference or feedback loops.
    • Testing and Optimization: After installation, perform thorough testing of the system to ensure that signal strength meets or exceeds the minimum requirements throughout the building. Adjustments to antenna placement, BDA settings, and other system components may be necessary to optimize performance.

4. Commissioning and Documentation

    • Acceptance Testing: Conduct acceptance testing in the presence of local fire or building code officials to demonstrate compliance with local codes and standards.
    • Documentation: Provide comprehensive As-Built documentation of the system, including design plans, specifications, installation details, and test results. This documentation is crucial for future maintenance, inspections, and modifications.

5. Maintenance

    • Regular Testing: ERRCS must be regularly tested to ensure they remain functional and compliant with local codes. This includes signal strength tests, battery backup tests, and inspections of all system components.
    • Maintenance Plan: Develop a maintenance plan that includes regular inspections, testing, and any necessary repairs or upgrades to keep the system operational and compliant over time.


From a components standpoint, there are a number of items that are common to all projects.

1. Signal Source

    • Donor Antenna: Captures the external public safety signals to be amplified and redistributed within the building, typically from an antenna on the roof of a building.
    • Fiber-fed Signal Source: Uses a fiber optic connection to receive signals from a remote location or directly from a public safety network.

2. Bi-Directional Amplifier (BDA)

    • Amplifies Weak Signals: BDAs boost the strength of incoming (downlink) and outgoing (uplink) radio signals to ensure they can penetrate throughout the building.
    • Supports Multiple Frequency Bands: Modern BDAs often support multiple frequency bands (e.g., VHF, UHF, 700/800 MHz) to accommodate the various frequencies used by emergency services. There are a number of manufacturers of BDAs and the integrator should be certified in the one that is being installed.

3. Distributed Antenna System (DAS)

    • Internal Antennas: A network of antennas placed strategically throughout the building to ensure uniform signal distribution, including in hard-to-reach areas like stairwells, basements, and elevators. Depending on the building, aesthetic considerations may drive antenna decisions.
    • Cabling: Coaxial or fiber optic cables connect the antennas to the BDA and signal source, transmitting the amplified signals throughout the building.

4. Power Supply and Backup

    • Battery Backup: Ensures the ERRCS remains operational during power outages, a critical feature for emergency systems. Battery backup systems are designed to comply with local codes, often providing power for 12 to 24 hours.
    • Power Supply Units: Convert AC power to DC power required by the BDA and other system components, ensuring stable operation.

5. Monitoring and Control Components

    • Alarm Panel: Provides alerts for system malfunctions, power failures, or other issues requiring attention.
    • Network Interface: Allows for remote monitoring and management of the ERRCS, uring that any issues can be quickly identified and addressed.

6. Ancillary Equipment

    • Signal Splitters and Combiners: Used to divide or combine signals in the system, ensuring efficient distribution of the amplified signal to all antennas.
    • Filters and Duplexers: Ensure that the ERRCS amplifies only the designated public safety frequencies, avoiding interference with commercial cellular or other non-emergency communication systems.

7. Enclosures

    • Racks and Cabinets: House the BDA, power supplies, and other electronic components, protecting them from physical damage and unauthorized access.


ERRCS are a critical components of building life-safety systems and are typically integrated and monitored by the fire alarm control panel (FACP). Their installation required a company with radio frequency expertise. If you need help with a project, please reach out to In-Building Wireless Solutions.