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Every minute counts when it comes to saving people during a crisis. First responders need to have clear and concise radio communication in all areas of a building – especially in spaces where signals can get lost. A Bi-Directional Amplifier (BDA) system overcomes this obstacle by boosting in-building Radio Frequency (RF) signals. This radio signal solution is programmed to perform in structures with dead zones, which occur when radio signals are blocked by metal, concrete, steel windows and other factors. Read on to discover four things you need to know when choosing a BDA system for your customers.

1. Key benefits of a BDA system

Keeping first responders and the ones they're protecting safe is crucial when choosing a BDA system. There are three main reasons why you should install a BDA system for your customer's building: safety, peace of mind and clear-cut communication.

  • Safety – A BDA system also known as, Emergency Responder Communication Enhancement System (ERCES), offers life-safety protection when a crisis hits. A BDA can alert emergency responders and detect when something goes wrong.
  • Peace of mind – Building owners, occupants and first responders can rely on BDAs to help prevent further damage and injuries.
  • Clear-cut communication – A BDA lets first responders connect to each other during an emergency event. This allows them to get the job done without letting dead zones get in their way.

2. How does a BDA work?

A radio signal booster system is made up of a few devices that make it perform well in buildings with dead spots. Here are the six main components that a BDA system consists of and how it works.

  • Bi-Directional Amplifiers (BDA) – Usually comes with two amplifiers to enhance signals between the radio repeater, building, mobile device and radio network. These amplifiers send radio signals back and forth simultaneously.
  • Donor antenna – Typically installed on the rooftop of a building. This antenna sends signals to and from the radio tower or repeater site while connecting to the amplifier.
  • Distributed antenna – The Distributed Antenna System (DAS) provides an extra signal boost. This antenna connects to the amplifier by a coax cable.
  • Uninterrupted Power Supplies (UPS) – This works as an emergency battery backup in the event of a power loss.
  • Alarm communicator – Designed to monitor radio signals, this device alerts first responders whenever parts of the system start to fail.
  • Wiring – Use coax cables to connect the donor antenna to the BDA vertically and horizontally, as well as splitters and connectors.

3. What buildings need them?

Any commercial building, such as an apartment, school, stadium, government building or hospital, that has poor connectivity, requires a BDA system. Some buildings may require more than one amplifier depending on coverage needs. To check if a BDA system is needed for a building, check with your local Authority Having Jurisdiction (AHJ). The AHJ will conduct signal tests to determine whether or not a BDA is required in a building.

4. What are the code requirements?

Adding a BDA system helps bring a building up to code and keeps first responders protected and connected. The Emergency Responder Radio Coverage (ERRC) code states that all newly built buildings provide sustainable radio coverage for emergency responders. Making sure your radio signal booster is up to code is another important life-safety requirement for first responders and the building's occupants. To determine if your BDA system is up to code, review the requirements and licenses that are required by your AHJ.


First responders are faced with many challenges during a critical event, so don’t let poor connection signals be one of them. A Bi-Directional Amplifier (BDA) is a life-safety system that gives the right amount of radio signal coverage from the top floor to the ground level of a building. Installing a BDA can help save lives, prevent loss of property and give building owners that added peace of mind.

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