An Emergency Responder Radio Communication System, or ERRCS, is an amplification system that receives public safety radio signals from an off-air donor antenna and re-transmits them through in-building service antennas. This system is also commonly known as a BDA system or a Public Safety DAS (Distributed Antenna System).
The Emergency Responder Radio Communications System (ERRCS) is made up of:
- A donor antenna to receive off-air signals
- A BDA (Bi-Directional Amplifier) to amplify the low off-air signal strength to a high output power
- A series of cable and splitters to distribute the signal throughout the building
- Service antennas to transmit the signals at the end of each cable run
- A battery backup to keep the system running in case of a power failure
- An annunciator panel to display the status of the ERRCS System and inform first responders if their radios will work within the building
ERRCS is covered in both IFC (IFC Section 510: Emergency Responder Radio Coverage) and in NFPA 1221 Section 9.6 (Two-Way Radio Communications Enhancement Systems). Both of these require that all buildings that do not have adequate radio coverage, which can be determined with a benchmark test, must have an ERRCS system installed to provide the required coverage.
If a building fails benchmark testing, a design should be completed to comply with applicable requirements in the jurisdiction for the ERRCS system. This includes, but is not limited to: Choosing a BDA that supports the proper frequencies, including a donor antenna that meets requirements, using metallic raceways where necessary, complying with survivability ratings, covering applicable critical areas, and more. All of this information would be included in the permit set, which is typically sent to the building permit department of a city, who will share it with the AHJ and FCC License holder for approval.
Once the ERRCS system is designed and permitted, the installation may begin. Upon completion of the installation, the system must be turned up or commissioned. This process includes measuring the off-air signal, creating a link budget, measuring isolation, setting the gain (both uplink and downlink), ensuring no interference is being created from the system, connecting all required alarms, then completing a final test of the building. Once you are sure the system performs as expected, it is time for the final inspection with the AHJ. After the AHJ signs off on the system, it can be left on-air for first responders to utilize when inside the building. Typically, no maintenance is needed outside of the code-required annual inspection, unless interior renovations or nearby construction occur.