Radio & Technology

system that helps ensure the safety of building occupants and first responders by extending the coverage of the public safety radio system to the interior areas of the building using an amplifier and a network of indoor antennas strategically located connected to an outside donor antenna to provide reliable public safety radio system coverage throughout the interior of a building.

DAS stands for distributed antenna system.  It is a system consisting of antennas, fiber, and coaxial cable that distributes radio signals throughout a building. 

The difference between a BDA and a DAS is how the signal is rebroadcast throughout the building.  In large buildings, a DAS will use fiber rather than coaxial cable to extend the signal throughout the building.

A donor antenna, located on the roof of the building, transmits and receives radio signals to and from the radio site antenna. The antenna is connected to an amplifier, which boosts the signal before sending it throughout the building using coaxial cable.

In emergency situations, a BDA benefits both occupants and first responders, to include paramedics, firefighters, and police officers.  First responders need a reliable radio signal for critical communication, so they can do what they’re trained to do – protect the lives and property of the occupants, as well as their own.

If a radio signal cannot be received or transmitted from within a building at a certain level, then the building needs a BDA.  The signal strength in a building can be affected by construction materials and location.  Construction materials that block radio signals are metal, concrete, ceramic tiles, and tinted or Low-E glass.  The thickness of walls can also affect the radio signal’s strength.  The proximity of the building to the donor-site antenna, as well as objects between the radio site and building could also affect signal strength, and therefore, determines whether a BDA is needed.

A qualified vendor, that has employees with two-way radio communication system knowledge and experience, conducts a radio signal strength grid test which is submitted to the authority having jurisdiction (AHJ) and the Federal Communications Commission (FCC) license-holder.  The two parties use the calculations on the grid test to determine whether a building will need a BDA.

The authority having jurisdiction (AHJ) determines whether a building needs a BDA.  In Pinellas County, the AHJ is the Fire Marshal of the municipality in which the building is located and the license holder, Pinellas County’s Radio Department of Safety & Emergency Services.

Following is a portion of Florida State Bill 2023 Chapter 633.202(18):

The local authority having jurisdiction shall determine the minimum radio signal strength for fire department communications in all new and existing buildings. Two-way radio communication enhancement systems or equivalent systems may be used to comply with the minimum radio signal strength requirements. However, two-way radio communication enhancement systems or equivalent systems are not required in apartment buildings 75 feet or less in height that are constructed using wood framing, provided that the building has less than 150 dwelling units and that all dwelling units discharge to the exterior or to a corridor that leads directly to an exit as defined by the Florida Building Code. Evidence of wood frame construction shall be shown by the owner providing building permit documentation which identifies the construction type as wood frame. Existing high-rise buildings as defined by the Florida Building Code are not required to comply with minimum radio strength for fire department communications and two-way radio communication enhancement systems as required by the Florida Fire Prevention Code until January 1, 2025. However, by January 1, 2024, an existing high-rise building that is not in compliance with the requirements for minimum radio strength for fire department communications must apply for an appropriate permit for the required installation with the local government agency having jurisdiction and must demonstrate that the building will become compliant by January 1, 2025. Existing high-rise apartment buildings are not required to comply until January 1, 2025. However, existing high-rise apartment buildings are required to apply for the appropriate permit for the required communications installation by January 1, 2024. 

Here is a link to the full chapter: https://m.flsenate.gov/Statutes/633.202

The following is a portion of Pinellas County Resolution No. 23-24 (2023): 

1. All fire departments, whether enforcing the fire safety codes within the legal boundaries of incorporated or unincorporated Pinellas County, Florida must require all new and existing high-rise buildings to maintain a minimum signal strength of -102 dBm for all critical and non-critical areas with a Delivered Audio Quality (DAQ) of 3.4 or better.
2. The required radio signal strength and quality tests shall be coordinated with the radio section of the Pinellas County Safety and Emergency Services Department to ensure the appropriate signals are tested.
3. All tests showing compliance shall be submitted to the radio section of the Pinellas County Safety and Emergency Services Department. Buildings requiring two-way radio communication enhancement systems in order to comply with the standards must obtain the provisional retransmission authorization which is required by the Federal Communications Commission (FCC). Provisional retransmission authorization is issued for initial system activation, optimization, and testing. Final retransmission authorization is issued upon successful commissioning of the system and is valid for a period of five years.
4. The radio section of the Pinellas County Safety and Emergency Services Department will have the authority to monitor the radio signal to mitigate any interference that is created by the improper design, installation or subsequent malfunction of two-way radio communication enhancement systems including the removal of the authorization for devices to retransmit, when necessary.

The minimum radio signal strength requirements are the same for all buildings, but the timeline for meeting the State Statute deadlines vary for existing buildings and new construction.

When determining which vendor to use for your BDA, choose a vendor that employs a licensed electrical engineer and an FCC licensed communication specialist with a General Radio/Telephone Operators License (GROL). Recently, the National Institute for Certification in Engineering Technologies (NICET), has developed a certification program for In-Building Public Safety Communications. The program provides technical knowledge of radio frequency theory, equipment mounting requirements, delivered audio quality, site survey data, and interpretation of the results.

Pinellas County does not recommend vendors.

DAQ stands for the delivered audio quality.  A scale of one to five is used to measure received voice quality. 

            DAQ 1: Unusable. Speech present

            DAQ 2: Speech is understandable with considerable effort.  Requires frequent repetition due to noise or distortion.

            DAQ 3: Speech is understandable with slight effort.  Requires occasional repetition due to noise r distortion.

            DAQ 3.4: Speech understandable without repetition.  Some noise or distortion is present.

            DAQ 4: Speech is easily understandable-little noise or distortion.

            DAQ 5: Perfect. No distortion or noise discernable.

Two adjacent buildings could have different BDA test results due to the construction materials or their relative position of the building to the donor-site antenna.  Radio signals will have a more difficult time penetrating buildings constructed of metal, concrete, and Low-E glass than those constructed of wood and regular glass.  Objects, such as trees and construction, between the donor-site antenna and the building may block the radio signal to one building and not the other.

No, new construction in the surrounding area or building modifications could alter the results of prior BDA tests. If public safety responders notice degraded audio quality, a grid test should be performed, and the results submitted to Pinellas County Radio Department and the Fire Marshal in the building’s municipality for review. 

No, installing a BDA in a building where one is not needed creates interference on the radio system. The increased noise could interfere with the public safety radio system to the point of disabling the entire site and the loss of all transmissions. To legally operate a BDA, the building owner needs to have Retransmission Authorization from the license holder, Pinellas County’s Radio Department of Safety & Emergency Services, or could face being fined by the FCC.

Installing appropriately rated conduit during the construction or renovation phase, will reduce the amount of demolition potentially needed to install future conduit, as well as the cost, should a BDA be needed in the future.

The FCC license holder, Pinellas County’s Radio Department of Safety & Emergency Services, is responsible for maintaining the licenses affiliated with the frequencies being amplified through the BDA.

1. Hire a vendor using a spectrum analyzer to test (not a portable radio).
2. What certifications do they hold? Most only have a GROL license, which is acceptable. With the addition of NICET’s newest certification for in-building public safety communications, you may start to see this certification soon.
3. How long have they been in business conducting bi-directional amplifier (BDA) tests? Many companies say they have been in business for much longer, but not necessarily in a BDA capacity. Check their website.
4. Can the vendor provide valid references?

Send test results to Pinellas County Radio & Technology at ratsupport@pinellas.gov to validate the results.

Call us with any questions at (727) 582-2510 or (727) 582-2529.