Originally posted on 1:59 PM on May 15, 2024
Last updated on June 21, 2024

What is a BDA System?

What is a BDA System?

By: Kati Bucciero on May 15, 2024
Last Updated: June 21, 2024

Poor in-building radio signals can lead to communication blackouts for emergency responders, delaying critical assistance in an emergency and risking lives. This is why Emergency Responder Communication Enhancement Systems (ERCES) or Bi-Directional Amplifier (BDA) Systems are now required in many commercial buildings, including high-rises and apartment buildings. They are also classified as a life safety system and monitored by a fire alarm system. As such, they are typically purchased with a fire alarm system and installed by a qualified contractor.

The Bi-Directional Amplifier (BDA) System along with its Distributed Antenna System (DAS) identifies, amplifies, and redistributes wireless signals throughout the building by boosting signals between a two-way radio system and an external antenna.

BDA systems fill potential gaps in areas of a building with weak or no radio signals, such as stairwells and parking garages. Radio frequency signals can also be blocked or reduced by many commonly used building materials like metal, cement, and even Low-E/energy-efficient windows.

Find out if your building has the proper signal coverage by scheduling a Radio Frequency Survey (Signal Survey). 

There are three components to these Emergency Responder Communication Enhancement Systems (ERCES).

  1. The Donor Antenna mounted on the rooftop which receives signals from outside the building.
  2. The Bi-Directional Amplifier (BDA) installed inside the building, which amplifies or boosts Radio Frequency (RF) signals in two directions.
  3. The Distributed Antenna System (DAS) installed throughout the building where needed to provide additional coverage.


typical BDA system in a building graphic

What Determines if a BDA System is Required?

Most building and fire codes for new and existing buildings specify necessary radio frequencies required to ensure uninterrupted communication for emergency responders.

BDA systems are a code-driven requirement determined by your specific building type as well as the fire and building codes adopted by your state and local jurisdictions. Most jurisdictions require BDA systems for all new construction, but now many are requiring them for existing properties. So now more than ever, property owners and managers need to be aware of their local jurisdiction’s requirements and consider a BDA survey to determine if they meet the required standards for Emergency Responder Radio Coverage (ERRC).  

Contact us today to speak with one of our trained and certified professionals about BDA system testing, design, installation, or maintenance

CTA Ultimate BDA Cheat Sheet Download (3)


Topics: BDA