BDA systems, also known as an Emergency Responder Communication Enhancement Systems (ERCES) or Bi-Directional Amplifier, is a signal-boosting solution designed to enhance in-building radio frequency (RF) signal coverage for public safety radios. Depending on the type of commercial or industrial facility you manage, you might find it difficult to communicate with every part of your building. This can be especially problematic for Emergency Responders who use their handheld radios when they need to make important or time-sensitive communications to other emergency responders. Building code requires that you correct this with a BDA system.