Bi-Directional Amplifier

Emergency Radio Communication Enhancement Systems


During an emergency, reliable communication is critical. Staying informed with clear radio transmissions between first responders inside a building and emergency personnel outside the building can help prevent further injuries and save more lives.

Emergency responders lose communications when in-building radio signals are weakened by structures such as concrete, windows, and metal. To solve these communication challenges, look no further than NOTIFIER.

NOTIFIER’s Bi-Directional Amplifier (BDA) System is a signal boosting solution designed to enhance in-building radio frequency (RF) signal coverage for public safety radio. When combined with NOTIFIER’s fire system, NOTIFIER provides reliability and quality expected from a life safety solution.

The Challenge: A Weak Radio Signal

The performance of emergency responders and public safety radio systems can be effected by building construction, building size, construction features and other elements that absorb or block radio communications. Signal strength can be negatively impacted by:

  • Concrete or metal construction
  • Large buildings
  • Underground structures
  • Low-E glass windows

An RF survey is conducted to determine if a building requires a BDA system. This survey, typically conducted by a specialized FCC GROL certified technician and some fire department radio personnel, measures the current buildings Downlink/Uplink signal strengths in decibels-milliwatts (dBm). Survey results are submitted to the Authority Having Jurisdiction – who will determine if a BDA solution is required.

The Solution: A Strong NOTIFIER BDA System

Tested and evaluated in accordance with UL 2524 requirements for In-building 2-Way Emergency Radio Communication Enhancement Systems, NOTIFIER’s BDA solution enhances two-way radio signal strength inside buildings, tunnels and other structures. The design delivers reliable performanceto meet signal strength requirements, even in the most challenging RF environments.

NOTIFIER Class B, Bi-Directional Amplifier Solutions are a high power, band-selective radio signal booster system that can be designed and customized to meet all public safety frequency band ranges. NOTIFIER’s state of the art BDA System is developed to provide a high rejection of interfering signals, convenient quick-disconnect terminals and built-in End Of Line (EOL) resistors for alarm connections, that allow for easy troubleshooting and channel expansion. At the same time, the signal booster is designed for excellent heat dissipation, corrosion resistance and ease of wall-mounting.


A BDA System is a Life Safety System. Similar to fire alarm, BDA is a code-driven requirement. The BDA system must be monitored by the building’s fire alarm system and annunciate the status of any signal booster(s). The monitoring panel shall provide visual and labeled indication of the following for each signal booster:

  • Normal AC power
  • Signal booster trouble
  • Loss of normal AC power
  • Failure of battery charger
  • Low-battery capacity

NFPA, IFC, and IBC includes requirements for the installation, performance, and strength of Emergency Radio Communication Enhancement Systems (ERCES) for commercial facilities.

  • The International Fire Code (IFC – Section 510)
  • NFPA 1221 (2016 Edition)
  • IBC 201 (Section 916)
  • UL2524 for In-building 2-Way Emergency Radio Communication
  • FCC Registration Number – FRN 0027204288