A Bi-Directional (BDA) System, or Emergency Radio Responder System (ERRS), ensure that buildings provide radio signal reception throughout their entire structures, including basements, stairwells, and “dead” areas that may be critical to first responders during a public emergency. A BDS System is also frequently referred to as a Distributed Antenna System (DAS).
Emergency Radio Communication Enhancement Systems (ERCES) were first introduced in the 2009 International Building Code. The ERCES requirement was established to address the performance of emergency responders’ portable radios inside buildings because building construction, building size, construction features, and other elements can absorb or block radio communications. If a building does not meet the required signal strength (-95dBm), the only effective solution is the installation of a signal booster called a Bi-Directional Amplifier (BDA) system.
This diagram illustrates the basic functionality that a BDS system (ERRS) provides to a structure that has “dead” or weak radio reception areas.