Common Fireground Noise May Cause Unintelligibility of Digital Radio Transmissions
FAIRFAX, Va. — The International Association of Fire Chiefs is alerting its members to a potential issue and soliciting their input to a solution. The IAFC has received reports of firefighters experiencing unintelligible audio communications while using a digital two-way portable radio when operating in close proximity to the low-pressure alarm of their self-contained breathing apparatus (SCBA). In addition, other common fireground noise, including powered tools, apparatus and PASS devices, may affect voice intelligibility.
This is an industry-wide issue and is not specific to any one manufacturer’s radios. There are indications that any digital voice communication product utilizing parametric voice encoders could be affected by this problem. The IAFC does know the problem is not related to any specific radio spectrum, as it is not a frequency of operation issue, or a particular communication standard.
Due to these reports, the IAFC board of directors has asked the Communications Committee to form a working group to work with other IAFC committees and sections and other appropriate organizations to investigate and provide recommendations to address this concern. The specific focus of the group will be to:
- Fully understand the facts and identify potential solutions that may be required.
- Facilitate industry collaboration among the communications equipment manufacturers to explore options to mitigate or eliminate this concern.
- Recommend best practices for digital portable radio use on the fireground.
The IAFC is asking you to contact the Communications Working Group if you have experienced similar issues. Go to www.iafc.org/digitalproblem to learn more about the tests you can conduct to provide the working group the information it needs to study the issue and make recommendations.
Your input is vital to ensure that digital radio technology can be effectively utilized in fireground applications. The IAFC fully understands that many fire departments are using digital radio systems with success, but there may be issues related to voice transmission being interfered with or overridden when common fireground noise is in the background.
We appreciate your assistance in testing your systems and reporting back to us.