By Connie Pignataro
Radio communication during an emergency is critical not only to effectively accomplish the task at hand but to keep firefighters and emergency medical services (EMS) personnel safe. A recent survey found that 98% of firefighters and 84% of EMS personnel experienced in-building communication problems, and 65% of first responders stated they experienced a communication failure within the past two years.1 To improve in-building radio communications, most U.S. states have adopted updated codes so that first responders will be able to communicate without fail inside structures during emergency operations.
The tragedy on September 11, 2001, at the World Trade Center brought to the forefront the need for better interior communication during emergencies. On that day, responding firefighters inside the buildings were unable to communicate effectively with their portable radios during the rescue operation. Many did not hear the evacuation order, which resulted in the deaths of 343 firefighters.2
Following 9/11, the National Institute of Standards and Technology (NIST) conducted an investigation under the then recently enacted National Construction Safety Team Act and recommended improvements for the current codes regarding in-building radio communications. Recommendation 22 specifically addresses emergency responder communication and safety. The report states that emergency communications systems and radio communications need to be effective in emergency situations, and these systems must be able to identify, track, and locate first responders within buildings.3
- Understanding Emergency Communications
- Communications Broke Down: An Excuse for a Serious Problem
- Fireground Communications: Command Considerations and Responsibilities
Organizations including the National Fire Protection Association (NFPA) and the International Code Council (ICC), publishers of the International Building Code (IBC) and International Fire Code (IFC), recognized the need to update codes to meet NIST recommendations. As a result, sections in these codes were either added or revised so that states and local jurisdictions that adopted the codes could begin enforcing them, thus improving in-building communications.
The IBC is adopted by the state or by local jurisdictions in all 50 states, while the IFC is adopted by the state or local jurisdictions in 41 states; 19 states have adopted NFPA 1, Fire Code, and 43 states have adopted NFPA 101, Life Safety Code®.4 These codes state that all buildings must have a minimum radio signal strength so that firefighters can communicate with each other, with command, and with dispatch. The firefighter must be able to transmit and receive communication using the portable radio anywhere within a building at all times. Fire departments can only enforce the IFC and NFPA codes that their local jurisdictions have adopted (Table 1).
If it is found that buildings do not have a minimum signal strength, then installation of an amplification system, a bi-directional amplifier (BDA), or a distributed antenna system is required. Amplification systems are also known as in-building emergency responder radio enhancement systems, public safety radio enhancement systems, and emergency radio communication enhancement systems. The authority having jurisdiction (AHJ) is responsible for interpreting the adopted codes so that the AHJ can enforce them locally.
According to Steve Wheeler, partner at JDRM Engineering and a registered communications distribution designer (RCDD), jurisdictions have to interpret the code and make decisions based on limited education. He and his colleagues developed a training class accredited by the Ohio Board of Building Standards designed to help AHJs better understand their adopted codes. He has conducted classes in Ohio, Indiana, Michigan, and Florida; many are grateful for the clarification the class offers. He is also a third-party site survey contractor. The code is great but is still evolving; it doesn’t cover everything it should, he says.
Radio Signal Site Survey
One item not addressed in any national or international code is a guideline for conducting the preenhanced emergency responder radio signal site survey. It also doesn’t identify the necessary qualifications of the technician conducting the survey. Although not included in adopted codes, local jurisdictions may add these requirements.
The site survey is important for fire departments because it will determine whether radio communication enhancement is necessary. With approximately 6.2 million commercial structures in the United States, this is a daunting task.5 The site survey report must be clear, concise, and informative.
“The criteria in the code to test a preenhanced building is very minimal,” Wheeler explains. In general, it says that the building must receive the first responder radio signal for inbound and outbound. There must be 95% coverage throughout the building at -95 decibels per milliwatt (dBm) inbound and -95 dBm outbound. On a per-floor basis, there must be 95% coverage, but the code doesn’t say how many areas or spaces to test, he says.
The codes do have requirements and specifications for the postenhancement emergency responder radio signal site survey, which is conducted after a new amplification system is installed. According to Wheeler, a quality preenhancement site survey should follow the postenhanced criteria. If it is good enough to use after a building has been enhanced, then it is good engineering practice to follow that same criterion for preenhancement.
To begin the test, the IFC (Chapter 5) states that each floor of the building must be divided into a grid of 20 equal areas. The technician must use the latest brand and model of the portable radio the agency uses. The radio must also be calibrated. The technician will test from the center of each square in the grid and perform a two-way communication with someone outside the building. If the communication at that center point fails, the entire square area fails the test. This procedure continues until the entire grid of each floor has been tested.6 The results must show 90% floor area radio coverage.
Additionally, NFPA 72, National Fire Alarm and Signaling Code®, and NFPA 1221, Standard for the Installation, Maintenance, and Use of Emergency Services Communications Systems, state that critical areas such as exit stairs, exit passageways, pump rooms, elevator lobbies, standpipe cabinets, and other areas that the AHJ has identified as critical shall have a 99% floor area radio coverage.
Measuring Signal Strength
The current codes state that radio signal strength should be measured using the delivered audio quality (DAQ) method, a subjective test score on a scale from 1 to 5, with 3 as a passing score. The test is conducted with the portable radios the local jurisdiction uses (Table 2).
Wheeler states that in addition to providing a DAQ score, he also measures the dBm with a spectrum analyzer. If radio enhancement is required, the BDA designer will need the dBm readings. According to Wheeler, the DAQ is basically a “Can you hear me now?” test that tells them that the radios work; the dBm measurement is needed to determine the signal strength. He cautions that a structure can pass a DAQ site survey but fail if using dBm measurement. He provides both measurements for the building owner and jurisdiction code officials.
Once the survey is complete, the technician will tabulate the results and prepare a report for the client.7 Wheeler cautions that site surveys can vary widely. He says a quality report should begin with the following items:
- The code requirements of the jurisdiction.
- The testing parameters (e.g., the jurisdiction’s frequency range and the radio system used).
- The testing equipment used and when it was last calibrated.
- The type of radio and radio antenna used.
- The testing method.
- The conclusion.
The report should also include a floor plan overlaid with the testing grid, color-coded testing results, and a table or spreadsheet showing the test results of each area (Figure 1). The report may also include an aerial map view showing the tower, the building, and the distance.
Figure 1. Site Survey Test Grid and Results
Source: JDRM Engineering.
The reason for radio coverage failure in a building varies. Radio signals may not be able to penetrate buildings depending on wall composition, low-e glass or other energy-saving cladding, and the specific frequencies the jurisdiction uses. Lower frequencies have been found to have better penetration.8
If the building being tested is newly constructed, it must be totally enclosed with all walls (including interior partitions), windows, doors, piping, ductwork, and roof in place. According to Wheeler, all these items will block some radio frequency, but pipes, ductwork, and low e-glass are some of the worst culprits, with low e-glass blocking radio frequencies by -35 to -56 dBm.
Depending on the size of the structure and access, a site survey can take approximately two to eight hours. The conditions and access will affect the length of time for the test. According to Wheeler, surveying a 1.2-million-square-foot manufacturing plant took him all day. An apartment complex of only 150,000 square feet also took him all day, because it had the 160 test areas and three floors.
If the report shows that the building passed the test, most AHJs will not require the building to be tested again unless major changes are made to the building itself or to structures surrounding the building. Also, a new structure near the tested building may affect the radio frequency in a previously tested building.9
If the report shows that the failure rate is less than 90% coverage and less than 99% coverage in the critical areas, the building owner will need to invest in a radio enhancement system. The AHJ is responsible for documenting this failure and following up with the building owner. This task generally is the responsibility of the local fire department’s fire prevention division.
Although the building owner is responsible to have the BDA installed, the owner must ensure that all codes are followed. Some jurisdictions require an independent third party to conduct the site survey. In this case, the company conducting the survey is not allowed to also install the BDA; Wheeler agrees with this concept. Although many radio companies have very high integrity, he says, some will tell you that you failed so they can sell a system.
The building owner or architect should give the site survey results to a radio enhancement systems designer to create a system to meet the building’s needs. Prior to installation, BDAs must be Federal Communications Commission (FCC) certified and registered with the FCC. The BDA must be tested following installation to ensure it is functioning properly.10
The testing and possible enhancements will require the building owner to budget for these expenses. Testing can cost from $250 to $1,500 for an average-size structure of between 5,000 and 150,000 square feet. Depending on the size of the building and the components required to enhance the radio signal, a building owner should plan on spending between $.75 and $2.00 per square foot.9
Per the IFC, radio enhancement systems need to be tested annually or more frequently if structural changes have occurred that could change the results from the previous survey. For example, if that building or a building near the structure underwent renovations or remodeling, this may obstruct the radio frequency. A major change of use can also affect the radio frequency.
It is essential that fire personnel be able to communicate effectively during an emergency. Although this transition may take some time and an investment by building owners, the result will ensure better communications during an emergency. This will provide a safer working environment for first responders, allowing them to more effectively perform their jobs while saving lives.
EndNotes
1. In-Building Public Safety Communications Survey. Zinwave and Safer Buildings Coalition. 2018. ZW Public Safety Survey Report 02-09-18 v2.indd. https://bit.ly/3GzR4ea.
2. Long, Coleen. 10 Years Later, N.Y. Responders Communicate Better. Associated Press. August 10, 2011. https://bit.ly/3nLgygg.
3. Shyam-Sunder, S. , Gann, R. , Grosshandler, W. , Lew, H. , Bukowski, R. , Sadek, F. , Gayle, F. , Gross, J. , McAllister, T. , Averill, J. , Lawson, J. , Nelson, H. and Cauffman, S. (2005), Federal Building and Fire Safety Investigation of the World Trade Center Disaster: Final Report of the National Construction Safety Team on the Collapses of the World Trade Center Towers (NIST NCSTAR 1), National Construction Safety Team Act Reports (NIST NCSTAR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.ncstar.1 (Accessed June 11, 2021).
4. Quick Response Fire Supply. ICC and NFPA Codes and Standards: A Basic Guide. January 7, 2020. https://bit.ly/2ZQiUm6.
5. Safer Buildings CoalitionTM. Safer Buildings Coalition–Has the Mission Changed? May 22, 2020. Safebuildings.org. https://bit.ly/3mxWQVE.
6. International Fire Code (IFC). International Code Council (ICC). (2018). https://bit.ly/3k5yEs9.
7. JDMR Engineering. Site Survey Report, Pemberton, Ohio 43450. https://emberly.fireengineering.com/wp-content/uploads/2021/11/2201FE_PignataroSiteReport.pdf.
8. Safer Buildings Coalition. In-Building Public Safety Primer. Retrieved July 1, 2021. https://bit.ly/2ZKMyZs.
9. Integrated Building Systems. FAQS: Fire Code and Emergency Responder Radio Systems [2021 Update]. Retrieved July 2, 2021. https://bit.ly/2ZRm88w.
10. National Fire Protection Association. NFPA 72, National Fire Alarm and Signaling Code. (2019 ed.). Retrieved July 2, 2021.
Connie Pignataro, CFEI, retired from the fire service in 2021 after more than 18 years of service. She served as a lieutenant firefighter/paramedic with Oakland Park (FL) Fire Rescue and later as a fire inspector/investigator for Boynton Beach (FL) Fire Rescue. She has a bachelor’s in applied science degree in public safety administration.
