An Emergency Responder Radio Communication System (ERRCS) has become a required in-building network in many municipalities around the country. The requirements for such systems are typically outlined by an entity called the “Authority Having Jurisdiction” or AHJ.

An ERRCS looks much like an Over-the-Air Cellular DAS in some respects, it uses a donor antenna to receive the radio signals from the local first responder network – signals that operate on private frequencies. These signals are then re-amplified in the building at the required locations.

ERRCS Components

There are numerous instances of graphical representations of the components of an ERRCS. You can Google “ERRCS” and any number of sites will show up with what is usually an over-simplified schematic of the components of an ERRCS. These usually involve a “Donor antenna” on the roof, cables to the MDF and then antennas distributed around each floor. In our search for something more granular (and in attempt not to reinvent the wheel), we found one instance that seems to stand out from the rest, courtesy of RF Signalman (, a California-based independent ERRCS testing company.

With their permission, we’ve included their schematic and Glossary in this month’s blog.

A detailed description of each component is outlined below. Click each document to view.

IBWS wishes to thank RF Signalman and Paul Niemann.

Contact Us

We at In Building Wireless Solutions are happy to answer any questions you might have about ERRCS. Contact us today by filling out the contact form on our website.