Your building's BDA system, explained for the people who run it

Concrete, steel, low-e glass and underground floors block radio. Firefighters inside your building talk on handheld radios, and in a stairwell or a parking level those radios can lose contact with dispatch and with each other. A BDA system picks up the public safety radio signal outside, amplifies it, and rebroadcasts it inside, in both directions: from the radio tower to the firefighter (downlink) and from the firefighter back out (uplink).

The FCC's definition is plain: a signal booster is "a device or system that automatically receives, amplifies, and retransmits signals from wireless stations into and out of building interiors, tunnels, shielded outdoor areas and other locations where these signals would otherwise be too weak for reliable communications" (47 CFR 90.219(a)).

It is a life safety system, like your fire alarm and sprinklers. Nobody notices it until the day it is needed.

Not every building has every part. Some systems use fiber and remote units instead of one central amplifier. Your installer's as-built drawings show what you actually have, and the fire code official can require them (IFC 510.4.2.7).

Four parties are involved, and only one of them is you.

• The fire marshal (AHJ). Decides what signal level the building needs, which areas are critical, approves the design, witnesses the acceptance test and receives the annual report. In Florida, the local authority having jurisdiction "shall determine the minimum radio signal strength for fire department communications in all new and existing buildings" (F.S. 633.202(18)(a)).
• The frequency license holder. Usually the county or city radio system. The system retransmits its licensed channels, so its written authorization is required before the system is turned on (NFPA 1225 18.7.2; 47 CFR 90.219(b)(1)(i)). In Florida, any new system or change needs this consent too (F.S. 633.202(18)(d)).
• Your installer or service vendor. Designs, installs, tests and repairs. The model code expects lead installers to hold an FCC general radio operator license and in-building system training, unless the fire code official accepts other proof of skill (IFC 510.5.3).
• Your monitoring company. Receives the system's trouble signals through the fire alarm. Some counties set their own rules here: Miami-Dade requires a service contract with a "runner" who responds within four hours of a trouble signal (Miami-Dade County Code Sec. 14-69(C), quoted in the MDFR guideline).

These five jobs land on the building side, whoever holds the title.

1. Book the annual test. The model code requires an inspection and test every year and after structural changes (IFC 510.6.1). NFPA 1225 requires a documented, signed test at acceptance and "once every 12 months" (NFPA 1225 20.3.10). Set a free reminder so it does not slip.
2. Keep the records. The amplifier gain readings from the acceptance test must stay on file with the owner, and if they are lost the owner can be required to rerun the acceptance test (IFC 510.5.4 item 6). Keep the permit, acceptance letter, every annual report, the licensee's written consent and the FCC registration confirmation together.
3. Act on trouble signals. A BDA trouble on the fire alarm panel means the system may not work right now. Call the vendor that day. See monitoring and supervision.
4. Protect it during construction. Roof work, ceiling work, new walls and window replacement can all change coverage. Tell your vendor before work starts, not after.
5. Pass along notices. If the county changes its radio system, Florida owners get at least 180 days' notice before changes are required (F.S. 633.202(18)(f)). Make sure that letter reaches whoever manages the system.

That depends on your state's fire code and your fire marshal, not on this page. For local rules by state and county, use the requirements hub on ERRCSCheck. Florida managers can also read how often a Florida fire marshal can require a coverage re-test.

Confirm every requirement with your fire marshal (AHJ) before you schedule work.