Emergency Radio Communication Enhancement Systems (ERCES) are required by International Building Code (IBC), International Fire Code (IFC) and they are specified in NFPA-1221 and NFPA-72.
NFPA 1221 Section 9.6 (2016 edition) and NFPA 72 Section 24.5.2 (2013, 2010 edition) dictates that radio coverage shall be provided with 99 percent floor area coverage in critical areas and 90 percent floor area radio coverage in general building areas.
IFC Section 510 (2015, 2012 edition) dictates that all new and existing buildings shall have approved radio coverage for emergency responders based upon the existing coverage levels.
Many cities and counties have their own ordinance requiring BDA systems — AHJ specifications are usually the bottom line and always the most important spec to meet, they always have the final say on specs.
FCC rules apply to all RF (Radio Frequency) Emitters (any device that emits RF energy), including BDAs. All BDAs must be FCC certified to be legally sold in the USA. Furthermore, all systems must be installed in accordance with applicable FCC rules and regulations.