When designing or upgrading a public safety DAS or cellular DAS system, one of the most crucial—but often overlooked—steps is conducting a Benchmark RF Grid Test. This test isn’t just a box to check during code inspections. It’s the foundation for reliable in-building wireless coverage and long-term DAS performance.

If you’re a building owner, property manager, or construction professional, understanding what a benchmark RF grid test is—and why you should perform it before any installation—can save you time, money, and failed inspections down the line.

Let’s explore how this test works, what it reveals, and why it’s a critical step in every wireless infrastructure project.

What is a Benchmark RF Grid Test?

A Benchmark RF Grid Test is a systematic, room-by-room evaluation of radio frequency (RF) signal strength across an entire building. It uses a grid-based layout (typically in 20×20-foot sections) to map the current signal environment and determine:

• Where RF signal strength meets acceptable thresholds

• Where dead zones or signal shadows exist

• How building materials affect signal propagation

• Whether the space meets code-required performance standards

This test is typically performed using certified spectrum analyzers, signal generators, and measurement software to collect accurate, high-resolution signal data.

Why Benchmark RF Grid Testing Matters:

• It identifies areas that need signal enhancement through DAS or BDA systems

• It establishes a baseline before any new construction interferes with signals

• It supports compliance with NFPA 1225, IFC 510, and local AHJ requirements

• It helps fine-tune the placement of antennas, cabling, and signal sources

Without this data, designing a DAS system is guesswork—and can lead to costly redesigns, re-inspections, or code violations.

 Explore the importance of code compliance in our guide on NFPA emergency radio coverage.

Key Components of an RF Coverage Map

The core output of a benchmark RF grid test is a color-coded heat map that visually displays RF signal strength across the entire building. This map is broken down by floor and room and serves as the starting point for any DAS design.

 Elements of an Effective RF Map Include:

1. Grid Zones

Each building floor is divided into a uniform grid, typically 20×20 feet, though smaller grids (e.g., 10×10 ft) may be used for critical areas like:

• Stairwells

• Elevator shafts

• Fire pump rooms

• Emergency egress routes

Each grid is tested for:

• Downlink signal strength (from tower to building)

• Uplink signal strength (from building to tower)

2. dBm Readings

Every zone is assigned a signal strength value, measured in decibels-milliwatts (dBm). This shows how strong or weak a signal is. The threshold for passing often includes:

• ≥ -95 dBm in general occupancy areas

• ≥ -90 dBm in critical areas

• These benchmarks align with NFPA and IFC requirements

3. Color Coding

Maps use color gradients to illustrate:

• Green: Signal meets or exceeds required threshold

• Yellow: Marginal coverage (needs enhancement)

• Red: Signal too weak or non-existent

This provides a visual diagnostic tool that anyone on your project team can interpret—especially AHJs reviewing your DAS plan.

4. Frequency Bands

The map also includes results across relevant frequency bands, including:

• 700 MHz (FirstNet / public safety LTE)

• 800 MHz (UHF public safety radio)

• 1900/2100 MHz (commercial cellular)

• 2.4/5 GHz (for Wi-Fi verification, if included)

Including multiple bands ensures the DAS or ERCES you deploy will support both public safety and commercial communication needs.

5. Documentation & Reporting

A benchmark test includes not just maps, but also:

• Raw RF data files

• Annotated floorplans

• Compliance verification reports

• Recommendations for DAS component placement

• Photos of test points and equipment

These records become part of your AHJ submission package and are used later for post-installation verification.

Let’s wrap up Part 2 of Blog #11 on Benchmark RF Grid Test, completing the remaining ~1,000 words to hit the 1,400–1,600 word target.

When and How to Conduct a Benchmark Test

A benchmark RF grid test should be viewed as a starting point in any building development or renovation project involving DAS or public safety communication systems. Timing it correctly ensures accurate signal data and avoids conflicts with later construction elements.

1. When to Conduct the Test

Here’s when to schedule a benchmark RF grid test:

• Pre-Construction (Best Practice): Conduct the test before framing and interior finishes are complete. This establishes a baseline for how well the external signal penetrates the building structure alone.

• Pre-Installation of DAS/ERCES: Right before installing DAS or ERCES, testing identifies the exact coverage gaps that need to be filled.

• Post-Installation (Comparative Validation): A second round of grid testing confirms that the newly installed system resolves signal deficiencies and meets NFPA/IFC standards.

• During Tenant Fit-Outs or Renovations: RF performance can change with major architectural modifications, particularly when new materials or room layouts are introduced.

2. How the Benchmark Test is Performed

Benchmark testing should only be performed by certified RF engineers using calibrated equipment. Here’s what a professional testing session typically involves:

Step 1: Building Grid Mapping

• Floorplans are divided into 20×20 ft zones (smaller in stairwells and mechanical areas)

• Critical areas are mapped and labeled separately

Step 2: Equipment Setup

• A spectrum analyzer is configured to scan designated public safety and/or cellular frequency bands

• A calibrated antenna is mounted on a portable tripod or handheld device

Step 3: Signal Capture

• Technicians walk to each test grid point and log signal strength readings

• Both uplink and downlink signals are recorded to detect any one-way communication issues

Step 4: Data Compilation

• Test results are uploaded into RF mapping software

• Floor-by-floor heat maps are generated with pass/fail indicators

Step 5: Results Review

• Engineers analyze results, compare with NFPA/IFC thresholds, and recommend DAS component locations (BDAs, antennas, cabling routes)

Need help getting started? Schedule a site survey with DAS Systems to determine your building’s current radio signal health.

Regulatory Expectations and Performance Standards

Benchmark RF grid tests are not just a good idea—they’re often mandated by code. Here’s how various fire and building regulations require and evaluate testing:

NFPA 1225 Requirements

• Signal testing must demonstrate a minimum of -95 dBm in 95% of all general building areas

• 99% coverage is required in designated critical areas

• Grid testing must use Class A or B calibrated test equipment

• Results must be documented and submitted to the Authority Having Jurisdiction (AHJ)

Read our full breakdown on NFPA 1225 and its impact on DAS systems.

IFC Section 510 Standards

• Requires grid testing as part of post-installation inspections

• Coverage thresholds vary slightly by jurisdiction but generally mirror NFPA

• Testing must be witnessed by or submitted to the local fire marshal or code enforcement officer

AHJ Documentation Expectations

Authorities often require:

• Annotated grid maps

• Raw test data logs

• Equipment calibration certificates

• Photos and timestamps of test points

• Engineering recommendations

Failure to provide adequate benchmark testing documentation may result in:

• Failed inspections

• CO delays

• Mandatory system redesigns

• Fines or code violations

Learn how DAS Systems manages AHJ coordination and inspections.

Conclusion: The Value of a Pre-Installation Benchmark

Benchmark RF grid testing provides an undeniable strategic advantage for building owners, engineers, and compliance officers. By mapping your building’s signal landscape early, you’re empowered to:

– Design a smarter DAS or ERCES system
– Avoid unnecessary coverage issues post-install
– Ensure code compliance from the outset
– Pass inspections on the first try
– Save time and money on retroactive system fixes

A benchmark test transforms the DAS design process from reactive guesswork to proactive engineering. It is the foundation for optimized in-building wireless coverage—and a must-have in today’s increasingly regulated building landscape.

Ready to Benchmark Your Building?

DAS Systems provides end-to-end support for:

• Pre-construction RF testing

• Public safety and commercial DAS system design

• NFPA 1225/IFC 510 compliance

• UL-listed equipment installation

• Annual recertification and remote monitoring

 Contact DAS Systems today to schedule your benchmark grid test or learn more about our comprehensive DAS services.