The 128-page National Fire Protection Association (NFPA) 1225 standard consolidates NFPA1061 and NFPA1226 to create a single source on emergency services communications systems. Professionals involved in public safety and commercial building operation should refer to NFPA 1225 for a better understanding of industry-approved qualifications for inspectors, as well as installation, maintenance, and uses of emergency communications systems.
Included in NFPA 1225 are procedures for installing and testing emergency responder communication enhancement systems (ERCES). First responders rely on ERCES to communicate with each other, as well as central dispatch during mission-critical situations. Therefore, ensuring they operate in every situation is essential to the safety of emergency personnel, as well as occupants of commercial buildings.
An ERCES Primer
Sometimes referred to as a Bi-Directional Amplifier (BDA) system, an ERCES is typically designed with repeaters, transmitters, receivers, and signal booster components. These in-building emergency responder radio systems also have remote annunciators and operational consoles, power supplies, and battery-charging system elements.
During a mission-critical situation, first responders rely on the ERCES to transmit and receive commands and instructions. Messages travel to/from the radios carried by trained emergency personnel through a building’s ERCES and a signal booster. An exterior antenna and a public safety radio repeater connect responders to central dispatch. Messages are also received by the land mobile radios (LMRs) of other emergency responders on the same communication channel through ERCES.
Effectively transmitting such important communications is adversely affected by the building’s design and construction. For example, Low-E glass, metal, and concrete often block or degrade wireless signals. For these reasons, neighboring buildings and structures can impact in-building radio communication, as well.
Originally, ERCES were used in high-rise buildings, however, ERCES deployment is changing, as noted in NFPA 1225. Buildings that are 5,000 square feet and larger may require ERCES in some districts. To ensure compliance – necessary for a Certificate of Occupancy – requires sound design and testing verification practices as defined by the Authority having Jurisdiction (AHJ) and NFPA 1225.
Designing an ERCES
The first step in constructing an ERCES is to conduct a site survey. A professional who holds a General Radiotelephone Operators License (GROL) performs the evaluation. To conduct the survey, the frequencies police, fire, EMS, and other first responders use within the jurisdiction must be known.
A spectrum analyzer is typically used for this process. It is tuned to the frequencies authorized by the respective jurisdiction. Once the survey is complete, the design of the system is completed using the data collected during the site survey, so the location of the distributed antenna system (DAS) can be properly planned.
Once the system has been installed, further testing must be done in accordance with Chapter 20 of NFPA 1225. Among the key measurements are signal-to-interference-plus-noise ratio (SINR), bit error rate (BER), and for cellular communications, Perceptual Objective Listening Quality Analysis (POLQA).
Meeting Standard Specifications
Many GROL-licensed inspectors utilize a dedicated land mobile radio analyzer, such as the LMR Master S412E (figure 1), to perform the necessary tests. In addition to a high-performance spectrum analyzer, it has a vector network analyzer (VNA), an internal power meter, and a vector signal generator.
Figure 1: The LMR Master S412E handheld analyzer is a dedicated public safety solution that can test ERCES.
Installers can use the internal VNA to view and adjust the RF performance of components within the system due to its transmission dynamic range performance of > 100 dB. Excellent DANL of -152 dBm and third-order intercept (TOI) of more than +16 dBm allows the instrument to identify and locate low-level signals that can interfere with land mobile radio systems. This is possible even if strong transmitters are in the proximity.
Additionally, support for various public safety systems is beneficial when selecting an analyzer for verifying network operation. For example, the S412E supports analog LMR analysis and can be optioned with a built-in TETRA analyzer, which also supports TETRA base station receiver sensitivity measurements, a P25 Phase1 and 2 signal analyzer, DMR (a.k.a. MotoTRBO) LTE analyzer, and more.
Effective In-building Coverage Mapping
Mapping tools are also useful to ensure ERCES system operation. Field test instruments with coverage mapping features can more effectively monitor RSSI and ACPR levels in emergency response systems. Compliance to NFPA 1225 also requires proper BER testing. Advanced mapping helps determine carrier-to-interference (C/I) ratio for accurate BER measurements.
Integrated software and hardware packages provide the ability to test and deliver accurate, single- or multi-story structure In-Building coverage maps in compliance with NFPA1225 (figure 2). A major obstacle in measuring these systems will be overcome by selecting a test and measurement solution capable of 100% situational awareness in the absence of a GPS signal to conduct accurate testing and map generation. These solutions provide coverage mapping of areas, including stairwells, elevators, and other areas critical to public safety requirements, that historically have been difficult or impossible to accurately map.
Figure 2: Example of in-building coverage mapping that can be used to verify public safety networks more accurately.
Compatible maps and complete building footprints are easily created via software, such as Map Master by Anritsu or Neon Command from TRX Systems and Anritsu. Entire indoor building facilities can be uploaded, or an address can be entered and the map captured. Once installed, the coverage mapping can begin with the touch of a button. The user has full control over the threshold values and measurement settings.
NFPA 1225 consolidates public safety communications qualifications for installers, as well as testing parameters. Anritsu provides a portfolio of solutions to address in-building public safety network verification to help ensure reliable communications between first responders in mission-critical situations through ERCES.