The in-building public-safety signal survey required by NFPA 1225 and IFC code. Grid-by-grid measurement that drives BDA design and AHJ sign-off.
An ERRCS walk test validates that a building has adequate public-safety radio coverage. The technician walks a defined grid through every floor with a calibrated receiver, recording signal strength and audio quality at each grid point. The pass/fail thresholds come from NFPA 1225 or IFC Section 510/1103, adjusted by the local AHJ.
A standard walk test takes 1 to 3 days depending on building size, uses a calibrated public-safety-band receiver, and records signal level and DAQ at every grid point plus 100% coverage of critical areas. The deliverable is a coverage heatmap, a measurement log, and a compliance summary scoped to the AHJ's acceptance template.
ERRCS (Emergency Responder Radio Communication System) walk test is the in-building public-safety signal survey that validates a building's public-safety radio coverage. The technician walks a grid through every floor with a calibrated receiver, recording signal level and audio quality (DAQ — Delivered Audio Quality) at each point, against thresholds set by NFPA 1225 or IFC Section 510 / 1103.
Typical thresholds: -95 dBm signal level over at least 95% of critical areas and 90% of general areas, with a DAQ score of 3.0 or better (clear, understandable speech without repetition). The AHJ (Authority Having Jurisdiction) sets the specific dBm and DAQ thresholds for their jurisdiction.
Standard practice divides each floor into a grid of approximately 20 ft × 20 ft squares (or 40 squares per floor for floors ≤ 40,000 sq ft). The technician records one measurement in each square. Critical areas (stairwells, elevators, fire command room, exit routes) are 100% covered regardless of grid pattern.
Delivered Audio Quality is a 1–5 subjective scale defined in TSB-88. DAQ 3.0 means 'Speech understandable with slight effort; occasional repetition required due to noise/distortion.' DAQ 3.0 is the minimum for public-safety radio compliance in most jurisdictions.
Three windows: (1) pre-design baseline — to determine whether a BDA is needed at all; (2) post-install acceptance — to validate the BDA system meets code before AHJ sign-off; (3) annual recertification — to confirm continued compliance. Some jurisdictions require quarterly battery checks plus the annual walk test.
Yes — walk-test, BDA install, and ongoing AHJ acceptance support is part of HexTel's wireless/in-building scope. See /glossary/das-vs-bda for the DAS vs BDA distinction, and /services/wireless for the full in-building scope.
A 30-minute scoping call covers your building, jurisdiction, AHJ posture, and the cleanest path to BDA acceptance.
