U.S. Fire Administration

Voice Radio 

Communications Guide 

for the Fire Service

June 2016

U.S. Fire Administration

Mission Statement

We provide National leadership to foster a solid foundation for 

our fi re and emergency services stakeholders in prevention, 

preparedness, and response.
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Voice Radio Communications Guide

for the Fire Service i

Acknowledgment

The U.S. Fire Administration (USFA) is committed to using all means possible for reducing the incidence of 

injuries and deaths to firefighters. One of these means is to partner with organizations that share this same 

admirable goal. One such organization is the International Association of Fire Fighters (IAFF). As a labor 

union, the IAFF has been deeply committed to improving the safety of its members and all firefighters 

as a whole. This is why the USFA was pleased to work with the IAFF through a partnership supported by 

the U.S. Department of Homeland Security (DHS), Science and Technology Directorate, First Responders 

Group, Office for Interoperability and Compatibility to develop this second edition of the “Voice Radio 

Communications Guide for the Fire Service.” The USFA gratefully acknowledges the following leaders of 

the IAFF for their willingness to partner on this project:

General President Harold Schaitberger

General Secretary-Treasurer Thomas Miller

Assistant to the General President

Occupational Health, Safety and Medicine Patrick Morrison

International Association of Fire Fighters, AFL-CIO, CLC

Division of Occupational Health, Safety and Medicine

1750 New York Ave., NW

Washington, DC 20006

202-737-8484

www.iaff.org

The IAFF also would like to thank Robert Athanas, Firefighter, Fire Department City of New York; Todd 

Bianchi, Captain, District of Columbia Fire Department; Jim Brinkley, IAFF Director of Occupational 

Health and Safety; Joseph Brooks, Radio Supervisor, Boston Fire Department; Thomas Chirhart, DHS; Billy 

Freeman, Lieutenant, Memphis Fire Department; Missy Hannan, Graphic Artist, International Fire Service 

Training Association (IFSTA)/Fire Protection Publications, Oklahoma State University; Ron Jeffers, Union 

City, New Jersey; Christopher Lombard, Captain, Seattle Fire Department; Andy MacFarlane, Phoenix, 

Arizona; Kevin Roche, FACETS Consulting; Wes Rogers, Lieutenant, Fairfax County Fire and Rescue 

Department; William Troup, USFA; Mike Wieder, Associate Director, IFSTA/Fire Protection Publications, 

Oklahoma State University; Cody Worrell, Firefighter, Phoenix Fire Department; and Mike Worrell, 

Battalion Chief, Phoenix Fire Department, for their efforts in developing this report.

The Federal Emergency Management Agency (FEMA) does not endorse, approve, certify or recommend 

any contractors, individuals, firms or products. Contractors, individuals or firms shall not claim they or 

their products are “FEMA approved” or “FEMA certified.”
Voice Radio Communications Guide

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Table of Contents

Acknowledgment..................................................................................................................................... i

Table of Contents..................................................................................................................................... iii

Section 1 — Introduction ....................................................................................................................... 1

Purpose............................................................................................................................................... 1

Why the Fire Service is Different ........................................................................................................ 1

Summary — Fire Service Environment............................................................................................... 2

Section 2 — Basic Radio Communication Technology.......................................................................... 5

Radio Spectrum................................................................................................................................... 5

Wavelength ......................................................................................................................................... 6

Channel Bandwidth ............................................................................................................................ 7

Radio Wave Propagation...................................................................................................................... 8

Interference......................................................................................................................................... 9

What Affects System Coverage?........................................................................................................... 10

Fixed-Site Antennas............................................................................................................................. 11

Downtilt.............................................................................................................................................. 13

Portable Radio Position ....................................................................................................................... 13

Mobile and Portable Antennas............................................................................................................. 14

Summary — Basic Radio Communication Technology....................................................................... 15

Section 3 — Digital and Analog Radio ................................................................................................... 17

Analog Radios..................................................................................................................................... 17

Digital Radios...................................................................................................................................... 18

Digital Audio Processing ..................................................................................................................... 19

Analog and Digital Comparisons ........................................................................................................ 19

Program 25 History ............................................................................................................................ 21

Program 25 Interoperability................................................................................................................ 21

Program 25 Characteristics in High-Noise Environments.................................................................... 21

Self-Contained Breathing Apparatus Mask Effect on Communications................................................ 22

Program 25 Digital for Firefighting..................................................................................................... 22

Summary — Digital and Analog Radio............................................................................................... 23

Section 4 — Conventional Radio Systems.............................................................................................. 25

Direct and Repeated Radio Systems..................................................................................................... 25

Direct/Simplex Communications on the Fireground........................................................................... 25

Receiver Voters — Improve Field Unit to Dispatcher Communications............................................... 26

Repeaters — Improve Field Unit to Dispatch and Off-Scene Units...................................................... 28

Simulcast Transmitter Systems ............................................................................................................ 30

Alerting............................................................................................................................................... 31

Summary — Conventional Radio Systems .......................................................................................... 31

Section 5 — Trunked Radio Systems...................................................................................................... 33

Basic Trunked Radio Operations ......................................................................................................... 34

Talkgroup Call..................................................................................................................................... 34

Call Disconnection .............................................................................................................................. 35

Designing a Trunked Radio System ..................................................................................................... 35

Capacity Design................................................................................................................................... 36

Coverage Design.................................................................................................................................. 36

Coverage Enhancement Devices .......................................................................................................... 37
Voice Radio Communications Guide

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Vehicular Repeaters............................................................................................................................. 39

Other Trunking System Features......................................................................................................... 40

Summary — Trunked Radio Systems.................................................................................................. 42

Section 6 — Portable Radio Selection and Use ...................................................................................... 43

General ............................................................................................................................................... 43

Ergonomics......................................................................................................................................... 43

Environmental Technical Standards..................................................................................................... 43

International Electrotechnical Commission Ingress Protection Codes.................................................. 44

Military Standards .............................................................................................................................. 44

How Many?......................................................................................................................................... 44

NFPA 1561 .......................................................................................................................................... 45

NFPA 1221 .......................................................................................................................................... 45

What Type? ......................................................................................................................................... 45

Multiband ........................................................................................................................................... 46

National Institute of Standards and Technology Testing ...................................................................... 46

Technical Note 1477............................................................................................................................ 46

Technical Note 1850............................................................................................................................ 46

NFPA 1802, Standard on Personal Portable (Hand-Held) Two-Way Radio Communications Devices for Use by 

Emergency Services Personnel in the Hazard Zone.................................................................................................... 47

Fire Radio Features.............................................................................................................................. 47

Portable Radio User Training Guide .................................................................................................... 48

Human Factors.................................................................................................................................... 49

Technical Factors................................................................................................................................. 49

Where to Wear Your Radio ................................................................................................................. 50

Coverage ............................................................................................................................................. 53

Accessories.......................................................................................................................................... 53

Summary — Portable Radio Selection and Use ................................................................................... 53

Section 7 — System Design and Implementation .................................................................................. 55

Project Organization ........................................................................................................................... 55

Requirements Definition..................................................................................................................... 55

Identify Operational Needs................................................................................................................. 56

Plan for Change................................................................................................................................... 56

Evaluation of Current System .............................................................................................................. 57

Funding .............................................................................................................................................. 57

Alternative Funding Sources................................................................................................................ 57

Grant Writing...................................................................................................................................... 58

Evaluation of Proposed Technologies .................................................................................................. 58

Technical Options and Conceptual Design .......................................................................................... 58

Should You Hire a Consultant or System Integrator?............................................................................ 59

Where to Get Advice ........................................................................................................................... 60

Procurement ....................................................................................................................................... 61

Developing the Request for Proposals ................................................................................................. 61

Evaluating Request for Proposals Responses........................................................................................ 62

Implementation................................................................................................................................... 63

Training and Transition....................................................................................................................... 63

Implementation Lessons Learned and Feedback .................................................................................. 64

Long-Term Operation and Maintenance.............................................................................................. 64

Summary — System Design and Implementation ............................................................................... 65
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Section 8 — Interoperability .................................................................................................................. 67

Frequency Coordination...................................................................................................................... 67

Interoperability Continuum ................................................................................................................ 67

Day to Day........................................................................................................................................... 68

Large Incidents ................................................................................................................................... 69

Communications Unit......................................................................................................................... 69

Summary — Interoperability ............................................................................................................. 71

Section 9 — Radio Spectrum Licensing and the Federal Communications Commission..................... 73

Rulemaking......................................................................................................................................... 73

Licensing............................................................................................................................................. 74

Federal Communications Commission Actions to Increase Public Safety Spectrum............................. 75

Further Narrowbanding...................................................................................................................... 77

Public Safety Wireless Advisory Committee ........................................................................................ 77

700 Megahertz Spectrum Allocation ................................................................................................... 77

800 Megahertz Reconfiguration.......................................................................................................... 78

T-Band ................................................................................................................................................ 79

Summary — Radio Spectrum Licensing and the Federal Communications Commission.................... 81

Section 10 — First Responder Network Authority or FirstNet.............................................................. 83

History................................................................................................................................................ 83

Formation of FirstNet.......................................................................................................................... 83

Cost..................................................................................................................................................... 86

Accessibility ........................................................................................................................................ 86

Survivability........................................................................................................................................ 87

Security............................................................................................................................................... 87

Public Safety Focus.............................................................................................................................. 87

Possible Fire Service Uses.................................................................................................................... 87

Summary — FirstNet.......................................................................................................................... 88

Glossary ................................................................................................................................................... 91

Acronyms................................................................................................................................................. 97
Voice Radio Communications Guide

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Section 1 |Introduction 1

SECTION 1 — 

Introduction

Purpose

The past few decades have seen major advancements 

in the communications industry. Portable 

communications devices have gone from being used 

mainly in public safety and business applications to 

a situation where they are in every home and in the 

hands of almost every American man, woman and 

child. As users are added, there is more stress on 

the system, and there is only so much room on the 

radio spectrum. The communications industry and 

the government have responded by making changes 

to the system that mandate additional efficiency.

These advancements have improved radio 

frequency (RF) spectrum efficiency but have 

added complexity to the expansion of existing 

systems and the design of new systems. Some of 

these advances in technology are mandated by the 

Federal Communications Commission (FCC), while 

others are optional. Many users of public safety 

spectrum have endured the time, effort and costs 

associated with narrowbanding. This effort created 

additional capacity in the existing spectrum, 

but performance of some existing systems was 

degraded when converted from 25 kilohertz 

(kHz) to 12.5 kHz. Even with narrowbanding, 

the appetite for RF spectrum continues to grow, 

necessitating continued efforts for spectral 

efficiency. “The migration to 12.5 kHz efficiency 

technology will require licensees to operate more 

efficiently, either on narrower channel bandwidths 

or increased voice paths on existing channels. 

This will allow creation of additional channels 

within the same spectrum, thereby supporting 

more users.”1

 The costs and operational effects of 

these changes are significant. The actual RF physics 

associated with moving to narrowband with no 

other system changes resulted in loss of range.2

Navigating through the complex technological and 

legal options of public safety communications led 

to the development of this guide to assist the fire 

service in the decision-making process.

The fire service is diverse. Departments range 

from those that are very large in size and have 

multimillion dollar budgets to small departments 

that rely on pancake breakfasts or bake sales to 

augment the operating budget. All departments, 

professional or volunteer, require reliable 

communications. The size of the budget does not 

change the physics or RF properties. All departments 

and firefighters need to understand basic radio 

principles to remain safe on the fireground and use 

communications equipment effectively.

Why the Fire Service is Different

The life safety of firefighters and citizens depends on 

reliable, functional communication tools that work 

in the harshest and most hostile of environments. 

All firefighters, professional and volunteer, operate 

in extreme environments that are markedly different 

from those of any other radio users. The radio is the 

lifeline that connects the firefighters to command 

and outside assistance when in the most desperate 

of situations. To operate safely in these dynamic 

environments, it is imperative that firefighters have 

the ability to immediately communicate information 

accurately. The importance was not lost by the 

firefighting community when they adopted the 

internationally recognized terminology mayday3

to signify an emergency situation. The mayday is 

often the “last chance” to get outside assistance, and 

the fire service’s ear is always listening for that call 

of distress. 

Environment

Firefighters operate lying on the floor, in zero 

visibility, high heat, high moisture, and wearing 

self-contained breathing apparatus (SCBA) 

facepieces that distort the voice. The incidents we 

operate on can be chaotic with an intense amount 

of fast-paced communications until the incident 

is stabilized. The fireground is filled with an 

extraordinary amount of noise. The only way to 

really understand the amount and intensity of the 

1 http://transition.fcc.gov/pshs/public-safety-spectrum/narrowbanding-faq.html.

2 http://www.cgwireless.com/images/NARROWBANDING_GUIDE_E_BOOK_JAN_2012.pdf, p. 31.

3 National Fire Protection Association (NFPA) 1561, Standard on Emergency Services Incident Management System and Command Safety, 2014 

edition, Chapter 6, 6.3.2.1.
Voice Radio Communications Guide 2 for the Fire Service

noisy environment is to experience it. The engines 

that drive pumps operating at high rpm, the sound 

of a circular saw blade sinking into a metal roll-up 

door, the roaring sound from an operating fire hose 

nozzle, the distorted high-volume voices straining 

through the mechanical voice ports of an SCBA 

facepiece are all part of our operating environment. 

Along with all of those challenges, we are enduring 

the prickly sensation of heat on our ears and hands. 

We adjust our position to “fluff up” the insulation 

in our turnouts, and even though our environment 

is hot, we have to keep a “cool head.”

We wear bulky safety equipment to overcome the 

temperature extremes that we are subjected to. 

The thermal extremes we encounter drive us to 

the floor and require us to crawl on our hands and 

knees or operate while lying down. These positions 

are not the optimal position to communicate with 

a device using radio waves. Gloves eliminate the 

manual dexterity required to operate portable radio 

controls, hoods and flaps that protect ears affect the 

ability to hear clearly, vision is diminished by the 

smoky environment, and SCBA facepieces distort 

and reduce the field of view. The facepieces impede 

voice communications, requiring the use of a loud 

voice to overcome the mechanical voice port unless 

the facepiece is equipped with some type of voice 

amplifier. All of the above are barriers to using 

radios effectively on the fireground. This requires 

firefighters to be intimately familiar with the radio 

equipment — being able to feel what the controls 

are by tactile sense and operating the radio.

Operations are conducted inside of buildings with 

various types of construction and size. The interiors 

of buildings can be as open as a warehouse or as 

confusing as a maze. Buildings can be as simple 

as a large shed to a multistory, energy efficient 

high-rise with many floors above and below. 

The construction type and materials used affect 

fireground communications by not allowing radio 

waves to penetrate the buildings. All of these factors 

must be considered in order to communicate in a 

safe and effective manner on the fireground. 

Radio system manufacturers have designed and 

developed radios and radio systems that meet the 

needs of the majority of users in the marketplace. 

The fire service is a small part of the public safety 

communications market and an even smaller part 

of the overall communications market. This has 

resulted in one-size-fits-all public safety radios 

and systems that do not always meet the needs of 

the fire service as a whole or those of a specific 

department. When you consider the extreme 

operating environment and the protective clothing, 

the fire service is unique among public safety and 

other municipal communications users. 

Fire Service Communications Model

The fire service operates in a staged state with 

resources located in fire stations. Calls are dispatched 

to specific units based on their location in relation 

to the incident. When more than one unit responds 

to an incident, an on-scene Command structure is 

established to coordinate fire attack, provide safety 

and accountability, and manage resources.4

 The 

units assigned to these incidents work for the local 

Incident Commander (IC) who is the focal point 

of communications on the fireground. During 

the initial attack, fireground communications are 

fast-paced and chaotic to the untrained listener. 

The dispatch center assumes a support role and 

simultaneously documents specific fireground 

events, handles requests for additional resources, 

and may record fireground tactical radio traffic. 

Summary — Fire Service Environment

The fire service operates in unique and 

challenging environments. The fire service 

recognizes the significance and importance of 

radio communications. The radio is the lifeline 

for firefighters in trouble. Use of the mayday term 

signifies the importance of the radio by using an 

internationally recognized term when in distress. 

Factors that separate fire from other disciplines:

•	 Communications pace — communications 

on the fireground are fast-paced and may be 

chaotic.

•	 Work position — firefighters are often on the 

floor crawling. This is not the optimal position 

for radio transmissions.

•	 Visibility challenges — heavy smoke and 

dark situations require users to be intimately 

familiar with the equipment.

4 NFPA 1561, 2014 edition, Annex G.
Section 1 |Introduction 3

•	 SCBAs pose several challenges:

– Voice ports on facepieces are difficult to 

communicate through.

– Visibility — restricts field of vision.

•	 Temperature and humidity:

– High heat.

– High humidity.

•	 High noise environments — difficult to 

communicate from the high noise area and 

difficult to hear in a high noise environment.

•	 Gloves and other personal protective equipment 

(PPE) restrict vision, hearing and the manual 

dexterity required to operate radio controls.

•	 Buildings vary greatly in construction and 

complexity. All buildings to some degree resist 

penetration of radio waves. The RF resistance 

varies on construction type, size and layout.
Voice Radio Communications Guide 4 for the Fire Service

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Section 2 | 5

Basic Radio 

Communication 

Technology

SECTION 2 — 

Basic Radio Communication Technology

When talking about fire department communications 

systems, usually we are talking about what are 

traditionally called Land Mobile Radio (LMR) 

systems. It is important for firefighters and fire 

officers to have a basic knowledge of radio system 

technologies to help them during the design, 

procurement or use of the radio system. By having 

this basic understanding, you will be able to 

participate effectively in critical discussions with 

technical staff, consultants, and manufacturers to 

get the safest, most effective voice communications 

system for your firefighters, command staff, 

and community.

Most radio system users do not need or have a 

detailed understanding of the technology behind 

the systems they use. However, such knowledge 

is important for those involved in procurement 

of the systems, in developing procedures for the 

use of the systems, and in training field users to 

have a more comprehensive understanding of their 

limitations, capabilities and operation. 

All technologies have strengths and weaknesses. 

Understanding those characteristics is important 

in making decisions related to the technologies. 

No matter what a salesperson will tell you during 

the procurement process, no system is without 

risk, and all have had users who were not satisfied 

with some aspect of the system. The key is in 

understanding the technology enough to ask 

questions, understand the answers, and make a 

successful evaluation.

Radio Spectrum

Radio communications are possible because of 

electromagnetic waves. There are many types of 

electromagnetic waves, such as heat, light and radio 

energy waves. The difference between these types 

of waves is their frequency and their wavelength. 

The frequency of the wave is its rate of oscillation. 

One oscillation cycle per second is called one hertz 

(Hz). The types of electromagnetic energy can be 

described by a diagram showing the types as the 

frequency of the waves increases (Figure 2.1).

Figure 2.1. The Electromagnetic Spectrum

10

MHz

VHF

Low

VHF

High UHF 700

MHz

700

MHz

1

MHz

1km 100m

1000m

10m 1m 10cm 1cm 1mm

1000μm

100μm 10μm 1μm

1000nm 100nm

100

MHz

10

GHz

Frequency Increases

Wavelength Decreases

AM Radio FM Radio/TV Wireless LAN Radar/Microwave

Infra

Red

Visible

Light

Ultra

Violet

100

GHz

1000

GHz

100

THz

1000

THz

10

THz

100

MHz

300

MHz

400

MHz

500

MHz

600

MHz

700

MHz

800

MHz

900

MHz

1000

MHz

200

MHz

1000

MHz

10

MHz
Voice Radio Communications Guide 6 for the Fire Service

When describing the frequencies used by common 

radio systems, we use metric prefixes to quantify 

the magnitude of the frequency. A typical 

frequency used in fire department radio systems 

is 154,280,000 Hz. This is a frequency designated 

by the FCC as a mutual-aid radio channel.5

 After 

dividing the frequency by the metric system 

prefix “mega,” equal to 1,000,000, this becomes 

154.280 megahertz (MHz).

Public safety LMR systems are allowed to operate 

in portions of the radio spectrum under rules 

prescribed by the FCC.6

 These portions of the 

spectrum are called bands, and LMR systems 

typically operate with frequencies in the 30 MHz 

(very high frequency (VHF) low), 150 MHz (VHF 

high), 450 MHz (ultra high frequency (UHF)), 700 

MHz, and 800 MHz bands. Also, UHF spectrum 

in the T-Band, 470-512 MHz, is available to public 

safety within a 50 mile radius of the eleven largest 

metropolitan areas.7

The wavelength is the distance between two crests 

of the wave. The frequency and wavelength are 

inversely related so that as the frequency of the wave 

increases, the wavelength decreases (Figure 2.2).

Figure 2.2. Electromagnetic Wave

Amplitude

Wavelength

Wavelength

The wavelength of the radio signal is a determining 

factor in the size and design of the antenna. Wave 

length is an actual distance that is usually measured 

in meters. Ham radio operators often do not refer to 

frequency band of the radio but use the wavelength 

to classify the radio. A VHF radio would be referred 

to as a 2 meter rig and a UHF radio would be a 70 

centimeter (cm) radio (Figure 2.3).

Figure 2.3. Radio Signal Wavelengths

50.0

50.1 6 Meters (50 MHz)

54.0 MHz

144.0

144.1 2 Meters (144 MHz)

148.0 MHz

420.0

219.0

222.0

220.0

70 cm (420 MHz)

1.25 Meters (222 MHz)

450.0 MHz

225.0 MHz

902.0

33 cm (902 MHz)

928.0 MHz

Figure a component of http://www.arrl.org/files/file/Regulatory/

Band%20Chart/Hambands_bw.pdf

A typical portable radio antenna is tuned to the 

frequency. We commonly hear the term onequarter wave or one-half wave antennas. What 

this means is that the wavelength is multiplied by 

0.25 or 0.5 to determine an optimal length for a 

transmitting or receiving antenna. 

The length of a radio antenna is related to the signal 

wavelength with which the antenna is designed to 

operate. In general, the higher the frequency of the 

5 U.S. DHS, Office of Emergency Communications, National Interoperability Field Operations Guide, Version 1.5, January 2014.

6 Code of Federal Regulations (CFR), Title 47, Part 90, Subpart B, 90.20.

7 The Middle Class Tax Relief and Job Creation Act of 2012 requires the FCC to auction the public safety T-Band spectrum by 

February 2021, and to clear public safety from the band within two years of conclusion of that auction. (Please see p. 79 of this 

document for additional information.)
Section 2 | 7

Basic Radio 

Communication 

Technology

waves used by the radio, the shorter the antenna 

on the radio. As you can see, the length of the 

antenna is based on science. The practice of putting 

a nonapproved longer antenna on a portable radio 

for a perceived performance improvement can 

actually damage a radio and should be discouraged. 

Users should always consult with their radio service 

provider before making any component change to 

maintain proper performance.

Channel Bandwidth

The radio spectrum is divided into channels. Each 

radio channel is designated by a frequency number 

that designates the center of the channel, with half 

of the bandwidth located on each side of the center.

Radio channel bandwidth is the amount of 

radio spectrum used by the signal transmitted 

by a radio. The greater the bandwidth, the more 

information that can be carried by the signal 

in the channel. Minimum channel bandwidth 

typically is limited by the state of technology and 

the bandwidth required to carry a given amount 

of information. Standard bandwidth has decreased 

several times in the past to accommodate more 

users. However, there is a theoretical limit below 

which the bandwidth cannot be decreased. In 

addition, the actual width of a channel often 

is slightly greater than the minimum width, to 

provide some space on each side of the signal for 

interference protection from adjacent channels. For 

the purposes of radio licensing, the FCC sets the 

maximum and minimum bandwidth for channels 

in each frequency band.

The bandwidth of channels typically used in 

LMR is measured in thousands of Hz, or kHz. In 

an effort to place more communications activity 

within a limited radio spectrum, permitted 

bandwidth has been decreasing. Under older 

licensing rules, some of which are still in effect, 

typical channel bandwidths were 25 kHz. Rule 

changes effective Jan. 1, 2013, now require 

frequencies below 512 MHz to have bandwidths 

of 12.5 kHz. The narrowbanding of this spectrum 

increased the channels available for licensing 

(Figure 2.4). 

Figure 2.4. Channel Bandwidth

150.815

150.8225 150.8375 150.8525 150.8675 150.8825 150.8975

150.830 150.845 150.860 150.875 150.890 150.905

Old 25 kHz bandwidth channels spaced at 30 kHz intervals

Old 25 kHz bandwidth channels spaced at 15 kHz from the original channels

12.5 kHz bandwidth channels at 7.5 kHz spacing from existing channels
Voice Radio Communications Guide 8 for the Fire Service

Figure 2.5. Two Slot Time Division Multiple Access

Spectrum efficiency is further improved by 

creating time slots within the bandwidth allocated 

thus creating two talk paths. As you can see in 

Figure 2.5, each frequency has two time slots 

that allow two talk paths on a single frequency. 

Digital radio technology allows use of frequency 

division multiple access (FDMA) or time division 

multiple access (TDMA) technologies. FDMA is 

being employed on many P25 Phase 1 trunked 

radio systems using 12.kHz and 25 kHz channels. 

A newer iteration of P25 — that is, P25 Phase 2 — 

uses TDMA technology to provide an effective 6.25 

kHz bandwidth or in industry terms, a 6.25 kHz 

equivalent bandwidth. Digital is optional in most 

bands but is required on interoperability channels 

in the 700 MHz band.

Radio Wave Propagation

To send a radio signal from a transmitter to a 

receiver, the transmitter generates electromagnetic 

energy and sends that energy through a 

transmission line to an antenna. The antenna 

converts that energy into electromagnetic radio 

waves that travel at the speed of light outward 

from the antenna. If another antenna is located 

in the path of the waves, it can convert the waves 

back into energy and send that energy through a 

transmission line to a receiver (Figure 2.6).

Figure 2.6. Electromagnetic Signal Radiation

Radio signals emitted from an antenna travel both 

a direct path to the receiving antenna and a path 

reflected from the ground or other obstacles. This 

reflection causes the wave to travel a longer distance 

than the direct wave, as shown in Figure 2.7.

Figure 2.7. Signal Paths
Section 2 | 9

Basic Radio 

Communication 

Technology

The waves traveling over the reflected path then 

interfere with the direct waves, causing an effect 

known as multipath interference. Multipath 

interference causes a variation in the signal level 

at the receiver. The signal may be higher or lower 

than the direct signal depending on the position 

of the receiver’s antenna. As the antenna is moved 

around, the signal varies, and the user hears a signal 

that goes from strong and clear to weak and noisy.

Figure 2.8. Atmospheric Ducting

Atmospheric Ducting

Warm Air Layer

Cold Air

Extended range due to

ducting effect of

atmosphere

Normal Line of Sight Range

The atmosphere can have an effect on the range of 

radio waves. While on the surface this might be 

thought of as good, it is not. RFs are assigned and 

reassigned with enough geographic separation so 

they don’t interfere. At times, atmospheric layers 

can form causing a ducting effect (Figure 2.8). The 

radio waves are usually limited to a line of sight 

range. When these atmospheric ducts form, the radio 

wave propagates out and hits the warm air layer and 

bounces between the warm air and ground, greatly 

increasing the range. The increased range often is the 

cause of interference on the far end due to the reuse 

of the frequencies. This condition is more prevalent 

in the lower frequency bands. 

Radio waves can travel through some materials, 

such as glass or thin wood, but the strength is 

reduced due to absorption as they travel through. 

Materials such as metal and earth completely block 

the waves due to their composition and density. In 

addition, some materials will reflect radio waves, 

effectively blocking the signal to the other side. 

Because buildings are built from many types of 

materials, the radio waves can be passed through 

some, be reflected by some, and be absorbed by 

others. This, along with the complex interior 

design of a building, creates a very complex 

environment for radio communications inside a 

building (Figure 2.9).

Figure 2.9. Terrain Blocking

Transmitter

Transmitter Receiver

B Side View

A Top View

Shadow

Zone

Interference

RF interference can be either natural or man-made. 

Interference from internal noise occurs naturally 

in all electronic equipment due to the nature of the 

electronic circuit itself. Manufacturers take this into 

account during equipment design, and obtaining 

a low-noise design is not particularly difficult. In 

addition, natural noise is produced by sunspot 

activity, cosmic activity, and lightning storms. 

This noise usually is of small magnitude and not 

significant for most LMR communications. The 

exception to this is the VHF low band that is affected 

significantly by severe sunspot activity, sometimes to 

the point of completely prohibiting communications.

More significant to radio communications systems 

is the interference produced by man-made sources. 

There are many sources of interference that you 

may encounter. Some interference sources are 

expected, such as vehicle ignitions, electric motors, 

and high-voltage transmission lines, but computers, 

light ballasts, and new energy efficient bulbs (both 

compact fluorescent lights (CFLs) and light-emitting 

diodes (LEDs)) emit radio signals that can interfere 

with public safety radios.

In general, man-made interference decreases 

with an increase in frequency. The UHF band 

and, initially, the 800 MHz band are much less 

susceptible to man-made interference than the 

VHF low and high bands. When systems are not 

subject to significant interference, they are said 

to be “noise limited,” in contrast to “interference 

limited.” The large number of transmitters used by 

cellular telephone companies has created intense 

interference in the 800 MHz band.
Voice Radio Communications Guide 10 for the Fire Service

Although the separation of the channels allocated 

to cellular companies has reduced this interference, 

communications problems still can occur when a 

user is operating close to a cellular transmission 

facility. This type of interference is particularly a 

problem when the user is located near a cellular 

facility and the user’s radio system site is located 

much further away. This creates a situation called 

“near-far” interference. The user’s system signal 

strength is low, and the cellular signal is high, 

keeping the user’s radio from receiving the desired 

signal. The 800 MHz band always was regarded 

as the “cleanest” band with respect to man-made 

interference, and systems initially were noise 

limited. However, all systems in the band now 

must be designed for maximum interference 

from nearby transmitters, which requires more 

transmitter locations and higher power, creating 

more costly systems.

Interference from cellular transmitters is illustrated 

in Figure 2.10. The blue area in the center is the 

public safety transmitter, and in the center of the 

gray areas are the cellular transmitters.

Figure 2.10. Gray Areas are Near-Far Interference Holes

Intermodulation interference is caused directly 

by the mixing of two or more radio signals. The 

mixing most commonly occurs inside the receiver 

or transmitter of a radio. This mixing can create 

a third signal that is radiated from the antenna 

out to other radios. The mixing also can occur 

outside a radio in the transmission line or through 

rusty tower bolts or guy wires. Intermodulation 

can be difficult to identify, due to the large 

number of frequencies that may be present at large 

communications sites. 

Receiver desensitization interference, also called 

receiver overload, is caused by nearby high-level 

transmitter signals that overload the initial parts 

of the radio’s receiver. This overload prevents the 

receiver from detecting the weaker desired signals, 

making the receiver nonfunctional. Receiver 

desensitization occurs near high-power radio sites, 

such as television and radio stations, and also can 

occur in poorly designed repeater systems where 

the transmit and receive frequencies are too close 

in frequency. 

Several things can be done to reduce or eliminate 

interference. The first is the use of high-quality 

radio equipment. High-quality equipment has 

better transmitter and receiver performance that 

minimizes interference and reduces its effects. 

The use of receiver multicouplers, transmitter 

combiners, and repeater duplexers reduce the 

possibility of intermodulation and receiver overload 

by filtering the transmitter and receiver signals 

to ensure only those signals actually used by the 

system are passed through.

Radio system designers can reduce the possibility 

of their systems causing interference by selecting 

appropriate designs. By selecting the appropriate 

antenna and adjusting transmitter power levels, the 

system can minimize interference with other users 

of the same frequency. This allows more efficient 

use of the available radio spectrum and keeps more 

resources available for all users.

What Affects System Coverage?

The coverage of a radio communications system 

generally is described as the useful area where 

the system can be used reliably. Many factors 

affect coverage, including the radio power output, 

antenna height and type, and transmission line 

losses. However, the factor that most influences 

system coverage is the height of the antenna 

above the surrounding ground and structures. 

As systems age, the coverage of the system can 

change due to man-made structures that are built. 
Section 2 | 11

Basic Radio 

Communication 

Technology

System designers place antennas on towers or 

mountain tops to provide a more direct path from 

the transmitter to the receiver. In the case of one 

portable radio user transmitting directly to another 

portable radio user, having the radio antenna as 

high as feasible (hand-held at shoulder height) 

significantly improves system coverage.

Antennas have three major properties: operating 

frequency, polarization, and radiation pattern. In 

general, these properties apply whether the antenna 

is used for transmitting or receiving. The operating 

frequency of an antenna is the frequency at which 

the antenna acts as specified by its manufacturer. The 

antenna may operate outside its design frequency, 

but the performance of the antenna will be reduced. 

In LMR systems like those used by public safety, 

most antennas are vertically polarized. You can see 

evidence of this with the wire antennas mounted 

on the roofs of vehicles. Like car antennas designed 

for FM broadcast radio, they stick up vertically 

from the surface of the vehicle. 

The radiation pattern of the antenna is the shape 

of the relative strength of the electromagnetic 

signal emitted by the antenna. This depends on 

the shape of the antenna. The radiation pattern can 

be adjusted through antenna selection to provide 

coverage where desired and to minimize coverage 

(and interference) in undesired directions.

Fixed-Site Antennas

Fixed-site antennas are mounted on towers or 

buildings to provide the dispatch or repeater 

coverage throughout the service area (Figure 2.11).

The antennas used must be designed to operate in 

the system’s frequency band and, for best power 

coupling, should have a center frequency as close as 

possible to the actual operating frequency.

The radiation pattern for the antenna should be 

selected to provide a signal in the desired sections 

of the coverage area and have minimal coverage 

outside the desired coverage area. This will help 

ensure that the system is not interfering with 

other systems unnecessarily. The most basic 

practical antennas are omnidirectional and have 

approximately equal coverage for 360 degrees 

around the antenna. In fire service terms, a nozzle 

set to a wide angle fog would be equivalent to an 

omnidirectional antenna (Figures 2.12 and 2.13).

Figure 2.11. Antenna Tower and Antenna

(Photo courtesy Mike Worrell)

Figure 2.12. Fog nozzle set to wide angle sprays in all 

directions — 150 gpm
Voice Radio Communications Guide 12 for the Fire Service

However, as shown in Figure 2.13, the antenna 

pattern is more like a slightly flattened donut. This 

causes an area immediately under the antenna to 

have lower signal strength, and less coverage, than 

farther away from the antenna.

Directional antennas are used to direct the signal 

toward the users and away from unwanted 

areas. The antenna is said to have gain over an 

omnidirectional antenna in the direction of highest 

signal. If we think of this in fire terms, when 

we place a fog nozzle to straight stream, we are 

directing the same gpm in a focused direction as 

depicted in Figure 2.14. There is no increase in 

energy, but it is now focused in a specific direction. 

Directional antennas essentially do the same with 

RF energy. Figure 2.15 shows a directional antenna 

called a Yagi, along with its radiation pattern 

looking down on the antenna. The pattern shows 

a stronger signal from the front of the antenna and 

a weaker signal from the back. The signal strength 

protrusions behind the main signal are called 

lobes, and, in most cases, antenna designers strive 

to minimize this unintended signal.

Figure 2.13. Omnidirectional Antenna Pattern

Horizontal

Pattern

Solid

Pattern

Antenna

Axis

180°

0°

270° 90°

Figure 2.14. Fog nozzle set to straight stream focuses energy in one direction — 150 gpm

Figure 2.15. Directional (Yagi) Antenna and Pattern

270° 90° -30 -20 -10

180°

0°
Section 2 | 13

Basic Radio 

Communication 

Technology

Downtilt

When an antenna is located on top of a mountain 

or tall building, the coverage loss created by 

the “hole” in the radiation donut may have 

a significant impact on coverage in the area 

immediately around the antenna. To compensate 

for this, directional antennas can be tilted 

slightly to direct more of the signal downward

(Figure 2.16). This tilting is known as mechanical 

downtilt and increases the energy immediately 

below the antenna while reducing the maximum 

distance the signal will travel. Unfortunately, when 

using an omnidirectional antenna, tilting the 

antenna down in one direction will result in tilting 

the pattern up on the opposite side of the antenna. 

For this reason, special antennas with electrical 

downtilt are used when omnidirectional coverage 

is required, such as on a tall building in the center 

of the coverage area. 

Figure 2.16. Downtilt

Portable Radio Position

The principles discussed earlier affect the 

performance of the portable radio. When a user 

transmits from a portable radio using a speaker 

microphone and it is against the body, RF energy 

is blocked altering the omnidirectional radiation 

pattern. If you place your fog nozzle on wide and 

place it next to an object, that pattern is altered, and 

the stream is not directed in the desired direction. 

The same happens with the RF energy when the 

radio is against your body. Some energy is absorbed, 

and the remaining signal is shadowed by your body.

Antennas must be oriented in the correct position 

for optimal performance. When an antenna is tilted 

out of vertical, the signal received is not as strong 

as it would be if vertical. There is no ideal location 

to wear the radio as a firefighter. As firefighters, we 

need to be aware of the radio position particularly 

when having difficulty communicating. As our 

position is changed, the effectiveness of the radio 

changes with the new position. We must be educated 

users and know that we might need to alter our 

position or move the radio to better communicate. 

Simply reorienting the radio will often correct a 

communications problem (Figure 2.17).
Voice Radio Communications Guide 14 for the Fire Service

Figure 2.17. Radio Antenna Placement

Signal altered by body. Radio held vertically for best performance. Radio position to SCBA voice port is good. 

Radio protected in pocket.

(Photos courtesy Cody Worrell)

Mobile and Portable Antennas

In general, all mobile and portable radio antennas 

are omnidirectional to provide coverage 360 degrees 

around the radio user.

Vehicle antennas should be mounted so that they 

are not obstructed by equipment mounted on 

the top of the vehicle. Light bars, air-condition 

units, and master-stream appliances are some 

typical obstructions found on fire service vehicles. 

Some obstructions, such as aerial ladders on truck 

companies, cannot be avoided, and the designer 

must select the best compromise location.

Vehicle antennas mounted on the roof of fire 

apparatus can be damaged by overhead doors, trees 

and other obstructions. Ruggedized low-profile 

antennas often are a better choice, even if they 

have a lower gain than a normal whip antenna. A 

properly mounted intact antenna with a lower gain 

is much better than a damaged antenna of any type.

Portable antennas usually are provided by the 

portable radio manufacturer and are matched to 

the radio. In some cases, alternative antennas can 

be selected for the radio to overcome specific user 

conditions.

When a portable radio is worn at waist level, 

such as with a belt clip or holster, the user’s body 

absorbs some of the signal transmitted or received 

by the radio. In addition, the antenna is at a much 

lower level than if the user were holding the radio 

to his or her face for transmitting.

Since the radio system is designed for use with the 

antenna oriented vertically, the performance of the 

radio is reduced when the antenna is horizontal. 

This is particularly important for firefighters, since 

the radio they use may become oriented horizontally 

when they are crawling low inside a structure fire.
Section 2 | 15

Basic Radio 

Communication 

Technology

Summary — Basic Radio Communication 

Technology

Radio communication takes place using 

electromagnetic waves that travel from the 

transmitter to the receiver. These waves are defined 

by the number of oscillations per second or Hz. 

Wavelength is an actual length in distance that 

is determined by the operating frequency. The 

wavelength is a key factor in the determination 

of the antenna length. Antennas are tuned to the 

operating frequency of the radio. The practice 

of putting a longer antenna on to increase 

performance should be discouraged and can result 

in damage to the radio.

Radio channel bandwidth is the amount of radio 

spectrum used by the signal transmitted by a radio. 

The greater the bandwidth, the more information 

that can be carried by the signal in the channel. 

Minimum channel bandwidth is limited by the 

state of technology and the bandwidth required 

to carry a given amount of information. Standard 

bandwidth has decreased several times in the past 

to accommodate more users. Rule changes effective 

Jan. 1, 2013, now require frequencies below 512 

MHz to have bandwidths of 12.5 kHz. Digital radio 

technology allows use of TDMA, and it is being 

employed on many P25 trunked radio systems to 

increase capacity, even though it is not mandated. 

Use of TDMA provides an effective 6.25 kHz 

bandwidth or in industry terms a 6.25 kHz 

equivalent bandwidth.

Transmitted radio waves can be reflected or absorbed 

by materials, such as buildings, the earth or trees, 

reducing the strength of the wave when it reaches 

the receiving antenna. Elevating the transmitting or 

receiving antenna will reduce the likelihood of the 

wave being affected by buildings or trees because the 

path to the receiver will be more direct.

Interference from undesired radio waves is always 

a possibility in a radio system. The potential for 

natural interference decreases as the frequency 

band increases, but man-made interference 

is very high in the 800 MHz band due to the 

proximity of cellular and other nonpublic safety 

communications systems. This interference can 

make it difficult to communicate effectively in the 

presence of the interference.

When designing radio communications systems, 

the designers must take into account the 

presence of reflecting or absorbing materials and 

interference. This may require constructing taller 

towers to support the antennas or increasing 

the power of the transmitters to overcome the 

loss of signal strength and interference. The 

system’s design must account for local terrain, 

trees, buildings and the density of interferencegenerating sources.

Antennas are designed with radiation patterns to 

direct RF in the desired direction. This is very 

similar to the use of a fog nozzle on the fireground. 

The nozzle can be adjusted in a wide pattern to 

spread a set gpm or can be set to straight stream to 

focus the same gpm in a specific direction.

When using a portable radio, users must remember 

that their body absorbs some of the RF energy and 

the antenna must be oriented properly for the best 

radio performance. There is no ideal location to 

wear the radio as a firefighter. As firefighters, we 

need to be aware of the radio position particularly 

when having difficulty communicating. As our 

position is changed, the effectiveness of the radio 

changes with the position. We must be educated 

users and know that we might need to alter our 

position or move the radio to better communicate. 

Simply reorienting the radio will often correct a 

communications problem.
Voice Radio Communications Guide 16 for the Fire Service

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Section 3 | 17 Digital and 

Analog Radio

SECTION 3 — 

Digital and Analog Radio 

Several different types of radios are used in the fire 

service. These radios can be classified as mobile, 

portable or fixed. They operate in either analog 

or digital mode on direct, repeated or trunked 

systems. This section discusses the operation of 

these types of radios and the features, benefits 

and problems associated with their use in the 

fire service. All technologies have strengths and 

weaknesses. It is important for the fire service to 

understand the strengths and weaknesses of all 

communications technologies to be able to make 

informed decisions to keep members safe.

Mobile radios are designed to be mounted in 

vehicles and get their power from the vehicle’s 

electrical system. They can be of either a one- or 

two-piece design, with the radio itself separated 

from the controls. An external antenna is 

connected to the radio and permanently mounted 

to the vehicle. Mobile radios usually have better 

performance than portable radios, including better 

receivers and more powerful transmitters. One 

exception to this is that mobile radios used in 

trunked radio systems may or may not have more 

powerful transmitters because the systems are 

designed for portable use, reducing the need for 

high-powered transmitters.

Portable radios are hand-held radios powered by 

rechargeable, replaceable battery packs or power 

sources. They usually have an external rubber 

antenna attached to the top of the radio.

Mobile and portable radios have similar controls 

to perform their essential functions. These include 

things such as changing channels, adjusting the 

speaker volume, and transmitting. The common 

names for these controls are the channel (or 

talkgroup) selector, volume adjustment, and pushto-talk (PTT) switch. Some radios, particularly 

those intended for fire and police use, will have an 

orange or red emergency button. This button may 

be programmed to indicate to the radio system and 

to other users that a user has an emergency. Older 

radios may have a squelch adjustment knob, but 

most modern radios have internal control settings 

or adaptive squelch so that a squelch adjustment 

knob is no longer necessary.

Base station radios are located at fixed locations 

and usually are powered by AC utility power. 

Base stations are generally higher in performance 

than mobile and portable radios, with higher 

powered and more stable transmitters and more 

sensitive and interference-resistant receivers. 

Some fire departments equip fire stations with 

base station radios to provide enhanced coverage 

throughout their service area and to provide 

backup communications in the event of a primary 

communications system failure.

Repeaters are similar to base stations, but they 

can transmit and receive at the same time, 

retransmitting the signal received by the receiver. 

Repeaters are used to extend the coverage of 

portable or mobile radios.

Radio console equipment is used by dispatchers to 

control base station radios and repeaters and allow 

the dispatcher to receive and transmit on one or 

more radios simultaneously. The consoles typically 

have individual volume and transmit controls for 

each radio as well as a master volume and transmit 

control. Headsets can be connected to the consoles 

along with footswitches, allowing dispatchers to 

operate the console hands-free so they can operate 

computer equipment simultaneously.

Analog Radios

The human voice is an analog signal. It is 

continuously varying in frequency and level. 

Analog radios have been in use since the invention 

of voice radio in the early 1900s. The type of 

analog radio used today was invented in the 1930s 

to improve on the older radio’s poor immunity to 

noise. These radio systems use FM to modulate the 

transmitted signal with the user’s voice. The main 

advantage of FM over older radio system types is 

that FM radios tend to reject (interfering) signals 

that are weaker than the desired signal.

Analog FM radios operate by causing the 

transmitting frequency of the radio to change 

directly with the microphone audio. Initially, the 

signal is filtered to remove any frequencies above 

human voice, but no other changes are made to 
Voice Radio Communications Guide 18 for the Fire Service

the signal. Figure 3.1a shows an example signal from 

the microphone, and Figure 3.1b shows the resulting 

change in frequency of the transmitted signal. 

Figures 3.1a and b. Frequency Modulation

TIME

(A)

(B)

AMPLITUDE

FM radios constantly have a signal at the output 

of the receiver, and a squelch circuit is used to 

mute the output of the radio receiver when no 

desirable signal is present. Squelch circuits mute 

the output automatically until the signal is strong 

enough to unmute. Older radios had adjustable 

squelch level controls, allowing the user to make 

the radio less sensitive if there was interference. 

However, most new radios have squelch levels that 

are adjustable only by radio technicians using radio 

programming software.

To further reduce received noise and interference, 

well-designed analog radio systems use Continuous 

Tone-Coded Squelch System (CTCSS) or DigitalCoded Squelch (DCS). CTCSS is also known by 

proprietary names such as Private LineTM (PL) or 

Channel GuardTM (CG).

CTCSS mixes a subaudible tone with the audio from 

the microphone and transmits the resulting signal. 

When a radio receives a signal with tone-coded 

squelch, the CTCSS decoder attempts to match the 

tone present in the received signal with the desired 

tone. If the correct tone is present, the receiver is 

unsquelched, and audio is routed to the speaker.

Digital Radios

To improve audio quality and spectrum efficiency, 

radio manufacturers introduced digital radios. 

Digital radio also provides a pathway for the FCC 

to improve efficiency and to meet the increasing 

requests for the radio spectrum. This is evidenced 

by a mandate to narrowband 700 MHz channels 

to a 6.25 kHz equivalent bandwidth by Dec. 31, 

2016. However, this mandate was eliminated by 

an FCC ruling made October 2014. The FCC stated 

the following “We conclude that the December 

31, 2016 narrowbanding implementation deadline 

is no longer viable. The record indicates that 

requiring narrowbanding by December 2016 

would force many licensees to modify or replace 

existing systems well before the end of their useful 

life. In addition, we share the concerns expressed 

by many commenting parties about the maturity 

of 6.25 kilohertz-capable equipment, including 

the lack of developed open standards governing 

major system components.”8

 The FCC recognized 

that many of the systems affected by the mandate 

would have been newer systems and that the 

mandate would require modification of systems 

that were not near end of life. 

Digital radio continues to be plagued with 

difficulties in processing voice with high 

background noise. Advancements have been made 

in the signal processing, but there continues to be 

instances where digital radios struggle. The prime 

examples continue to be Personal Alert Safety 

System (PASS) devices and SCBAs with vibrating 

regulators that signify low air. 

In the digital world, when a user speaks into the 

microphone the radio samples the speech and 

assigns the sample a digital value. A vocoder (voice 

coder) or codec (coder/decoder) in the radio 

performs the function of converting analog voice 

to a digital data packet. The digital data packet can 

vary in the number of bits. The use of digital audio 

was expected to reduce static and increase the range 

of radios in weak signal conditions. P25 vocoder 

manufacturer Digital Voice System Inc. (DVSI) 

has improved the Enhanced Vocoder’s ability to 

recognize and suppress high frequency noise. The 

result is improved voice quality and intelligibility 

8 FCC Report and Order, October 2014, FCC-14-172.
Section 3 | 19 Digital and 

Analog Radio

in high frequency noise such as PASS alarms. These 

improvements improve the performance of digital 

radios on the fireground. Radio manufacturers also 

continue to improve the technology by employing 

noise canceling features and embedding noise 

filtering options in the radios. 

Digital Audio Processing

In digital radios, analog voice is converted to a 

digital interpretation from an audio sample received 

from the microphone (Figure 3.2). P25 digital 

radios have very limited data rates and bandwidth 

available to transport the digitized voice. P25 digital 

vocoders are designed to encode and decode the 

frequency range and elements of human voice. For 

example, digital radios do not accurately reproduce 

pure tones. The inability to transmit tones affects 

departments that use tones to alert firefighters of 

specific events on the fireground. Human speech is 

a constant variation in frequency and amplitude. If 

you attempt to transmit a pure tone, the received 

audio will not be a true reproduction of the source, 

and it is noticeably different. 

This is a basic explanation of how analog voice is 

processed by the radio.

Transmitting radio:

1. The user speaks into the microphone.

2. The audio is sampled and converted to a digital 

interpretation by an analog to digital converter 

(A/D converter).

3. The vocoder converts the digitized speech into 

digital data.

4. The modulator modulates the RF with the 

digital data.

5. The modulated RF signal is boosted in power 

by transmitter amplifier.

6. The signal is transmitted from the radio antenna.

Receiving radio:

1. The modulated RF is received by antenna.

2. The received RF signal is boosted to a usable 

level by the receive amplifier.

3. The signal is demodulated by a demodulator. 

This removes the RF component of the signal 

leaving the digital data component.

4. Digital data is decoded by the vocoder into 

digitized speech.

5. Speech data is converted to an analog signal by 

a digital to analog converter (D/A converter).

6. Analog is sent to the speaker.

Analog and Digital Comparisons 

Distance

As the radio user travels further from the 

transmitting radio, the signal strength decreases. 

The signal strength directly affects the ability of the 

radio to reproduce intelligible audio.

In an analog system, the clarity and intelligibility 

of the transmission, as received by the user, 

decreases directly as the signal level decreases. The 

noise (static) in the signal progressively increases 

in strength, while the desired signal decreases 

Figure 3.2. Digital Radio

Vocoder

Demodulator

Modulator

Analog to

Digital

Converter

Radio

Frequency

Power 

Amplifier

Receive 

Amplifier

Digital to

Analog

Converter

Vocoder

Microphone

Antenna

Transmit

Receive 

Switch

Speaker
Voice Radio Communications Guide 20 for the Fire Service

until the transmitting user cannot be heard over 

the noise. When the signal level is high, the voice 

quality is high. As the signal level decreases, the 

voice quality decreases in a predictable manner 

giving the user hints that the signal is getting 

weaker. This characteristic adds to the situational 

awareness allowing the user to make decisions 

about the environment.

When a digital user transmits to a receiver, the 

transmitted signal decreases just as the analog signal 

decreases. However, the digital transmission contains 

extra data providing error correction and allowing 

audio to be recovered despite declining signal. As 

the receiver travels further from the transmitter, the 

signal level decreases to the point where the error 

correction cannot correct all errors in the signal. 

When this point is reached, the receiving users will 

hear some distortion in the signal and may hear 

some strange nonspeech noises. These noises are 

often referred to as digital artifact.Once this point 

is reached, a small reduction in signal level will 

cause the number of errors to exceed the ability of 

the system to compensate, and all audio will be lost. 

Although digital radios provide a larger range of 

usable signal levels, the lack of advanced indication 

of signal level decrease allows users to get closer to 

complete loss of communication with less warning 

than an analog radio. As you note in Figure 3.3,

the analog signal voice quality decreases in a near 

linear rate as signal level decreases. In comparison, 

digital voice quality has a steeper degradation when 

it reaches lower signal levels. 

Figure 3.3. Analog Versus Digital Signal

High

Performance 

Difference

High Low

Low

Analog Radio Digital Radio

RF Signal Level

Voice

Quality

John C. Hardwick, Ph.D., President, DVSI Presentation to NFPA 1802 

Technical Committee, Nov. 19, 2014, Tucson, Arizona

Voice Intelligibility

The ability to understand the digital radio 

transmissions has been a focus of many fire 

departments. After implementation of P25 digital 

systems, it was discovered that digital audio was 

not the same as analog, and the performance 

differences were most prevalent during fire 

operations. One of the most significant differences 

was attempting communications with a vibrating 

low air alarm or a PASS device alarming. 

In 2007, the International Association of Fire 

Chiefs (IAFC) formed a working group to address 

potential problems with P25 digital radio. 

The working group consisted of fire service 

personnel, other public safety representatives, 

wireless radio manufacturers, manufacturers of 

fire apparatus and equipment, and consultants 

to address potential problems found in digital 

radios in the presence of loud background 

noise.9

 Funding for this effort was provided 

jointly by the DHS Office of Interoperability 

and Compatibility, the National Institute of 

Standards and Technology (NIST) Office of Law 

Enforcement Standards, and the Federal Partnership 

for Interoperable Communications (FPIC). As a 

result of the findings of the IAFC workgroup, the 

National Telecommunications and Information 

Administration (NTIA) allocated resources to 

perform testing of the P25 vocoders in the 

firefighting environment. NTIA TR-08-45310 was 

released in 2008. The report identified performance 

differences between digital and analog radios. As 

we move forward in time, technology continues to 

advance. Emerging technologies and new vocoders, 

such as the ones used in cellphone technology (4G 

Long Term Evolution (LTE)), required testing. In 

response to emerging digital voice technologies, 

additional testing was performed by the NTIA. 

NTIA report 13-49511 documents the performance 

of the different technologies in the firefighting 

environment. This next section will focus on the 

performance contrast between digital radio and 

analog radio. 

9 http://www.iafc.org/digitalProject.

10 NTIA Technical Report TR-08-453 Intelligibility of Selected Radio Systems in the Presence of Fireground Noise: Test Plan and 

Results, http://www.its.bldrdoc.gov/publications/2490.aspx.

11 http://www.its.bldrdoc.gov/publications/2720.aspx.
Section 3 | 21 Digital and 

Analog Radio

Program 25 History

The Association of Public Safety Communications 

Officers (APCO), representing the public safety 

technical community and the Telecommunications 

Industry Association (TIA), recognized that 

there would be a requirement to move to digital 

technology. This provided an opportunity to 

develop an open standard that would allow different 

manufacturers to build equipment that could operate 

together. The goal was to introduce competition 

into the market, help control costs, and provide a 

technology platform for improved interoperability.

Up until the development of this standard, each 

manufacturer had proprietary digital radios that 

could interoperate only with like radios. Working 

with the TIA, APCO coordinated the work of 

manufacturers to develop the APCO P25 standard for 

digital radios. Modern public safety digital radios use 

this standard. P25 is the national standard for public 

safety digital radios but also is backward compatible 

for analog use. This standard was developed to allow 

radios from multiple manufacturers to communicate 

directly using a common digital language, to 

define standards for trunked radio systems to allow 

multiple manufacturers to operate on a common 

platform, and to provide a roadmap for future 

features and capabilities.

The TIA Engineering Committee (TR-8) 

formulates and maintains standards for private 

radio communications systems and equipment 

for both voice and data applications. TR-8 

addresses all technical matters for systems and 

services, including definitions, interoperability, 

compatibility and compliance requirements. The 

types of systems addressed by these standards 

include business and industrial dispatch 

applications as well as public safety (such as police, 

ambulance and firefighting) applications.

Much of the work of the committee relates to the 

formulation of the TIA-102 series standards for 

APCO Project 25. These are standards sponsored 

by the Association of Public Safety Officials 

International, the National Association of State 

Telecommunications Directors (NASTD), and 

agencies of the federal government. P25 standards 

are developed to provide digital voice and data 

communications suited for public safety and first 

responder applications.12

Program 25 Interoperability

P25 does not address any operational or 

interoperability needs. P25 also does not provide 

a fire department with interoperability unless it 

is planned for. A lone agency on P25 is no more 

interoperable than being on a UHF system trying 

to interoperate with a department on VHF. P25 

only provides manufacturers with a common 

digital language for the radios and system 

infrastructures. The use of the P25 standard 

has provided a common platform that allows 

technical interoperability between systems. This, 

in turn, provides the technical path to provide 

interoperability for public safety operators. 

P25 system standards also were meant to allow 

radios from different manufacturers to operate on 

any other P25-trunked radio system. While the 

intent was to provide complete interoperability 

between different trunked systems and portable 

manufacturers, the P25 standard allows 

manufacturers to implement nonstandard features. 

So a P25 radio may not have full functionality on 

a trunked system of a different manufacturer. The 

trunked systems available today offer many features 

and have complicated roaming schemes. If you are 

purchasing devices from a different manufacturer 

than your trunked system, care must be taken to 

thoroughly test to ensure all of the features you 

expect to use are functional. 

Program 25 Characteristics in High-Noise 

Environments

When P25 is used in settings where the 

background noise level is within limits set in the 

P25 standard, it provides usable audio. However, 

the P25 vocoder was not designed to operate in the 

high-background-noise environments encountered 

on the fireground. When the P25 vocoder was 

being developed, the designers tested intelligibility 

of the digital audio with high ambient noise levels 

at the receiving radio. The P25 vocoder is unable 

to differentiate the spoken voice from the high 

12 http://www.tiaonline.org/all-standards/committees/tr-8.
Voice Radio Communications Guide 22 for the Fire Service

background noise and assigns a digital value that 

does not accurately represent the voice. The result is 

unintelligible audio or broken audio with digitized 

noise artifact. Users of P25 radios have been 

affected by many common fireground noises. The 

SCBA alerting systems for low air or inactivity and 

PASS devices have made the audio transmitted from 

digital radios unusable. P25 radios transmitting 

from high-noise environments do not perform to 

the same levels as analog radios. 

Self-Contained Breathing Apparatus Mask 

Effect on Communications

The effect of SCBA masks on the human 

voice was published by the Institute of 

Electrical and Electronics Engineers (IEEE) 

Communications Magazine.

The testing in the IEEE article documents the 

effects of the SCBA system on voice intelligibility. 

Based on the testing, the conclusion was that 

“SCBA systems are frequently used by firefighters 

and other public service personnel who rely on 

speech radio communications to perform their 

work. The SCBA mask acoustically distorts speech 

and the breathing system produces noises that 

can detrimentally affect speech communications, 

especially when a digital speech codec is used 

in the communications link. Both speech 

intelligibility and speech quality are detrimentally 

affected by SCBA equipment use.”13

Feedback

The presence of feedback can be affected by the type 

of system the radio is on. In simplex/direct systems, 

the presence of feedback is all radios are on the same 

frequency. If transmitting near many other radios set 

on high-volume settings, the receiving radios squeal 

due to a feedback loop that is created. In digital 

radios, the same conditions exist, but the radios 

emit what sounds like “crickets.” In both analog 

simplex and digital simplex, it is important for users 

to be aware of this characteristic and shield the 

microphones from the other radios that are nearby.

Simultaneous Transmissions

When on the fireground, communications are 

often very fast, and many users are often trying 

to communicate at the same time. This can result 

in simultaneous transmissions. Simultaneous 

transmissions can be a hindrance to fireground 

communications, and there is a difference between 

analog and digital. In analog simultaneous 

transmissions, the result is a warble-like tone 

behind the voice. The technical term for this 

is heterodyning or mixing of frequencies. In 

analog, the receivers can hear that two units 

are transmitting and can ask for a repeat of the 

transmission. In digital, if the two signals are 

equal in strength, the receiver may quiet due to 

a corruption of the data stream. This can occur 

in any digital simplex/direct or digital repeated 

system where access is not controlled. Trunked 

systems only allow one user to transmit at a time, 

so this situation is highly unlikely.

Program 25 Digital for Firefighting

Fire departments and other emergency service 

agencies have successfully implemented digital 

radio systems. However, fire departments around 

the country have reported difficulties with 

digital radios.14 A simple Internet search of “Fire 

Department Digital Radio Problems” will yield a 

long list of problems encountered by firefighters 

using digital technology.15 To say that all digital is 

bad would be an incorrect statement. Each instance 

must be analyzed individually for the cause. What 

is important is to understand the cause of the 

communications problem and either design it 

out of the system or avoid use of the technology 

when it is does not meet operational requirements. 

This analysis should be done for any technology 

employed on the fireground. Studies performed 

by NIST, IAFC and portable radio manufacturers 

have supported the findings from the field users. 

Fire departments need to consider the performance 

differences between digital and analog technologies 

when researching new communications systems. 

13 IEEE Communications Magazine, January 2006, “The acoustic properties of SCBA equipment and its effects on speech 

communication,” William M. Kushner, Member IEEE, S. Michelle Harton, Member IEEE, Robert J. Novorita, Member IEEE, 

and Michael J. McLaughlin, Fellow IEEE.

14 http://www.iafc.org/files/digProj_DPWGinterimReport.pdf.

15 This website is a collection of information on radio system that can be of value: http://blog.tcomeng.com/index.php/digitaltrunked-radio-system-problems/.
Section 3 | 23 Digital and 

Analog Radio

This is supported by NFPA 1221, Standard for the 

Installation, Maintenance, and Use of Emergency Services 

Communications Systems, (2013 edition). It requires 

a tactical analog channel for on-scene 

communications.

9.3.1.3 A communications radio channel, 

separate from the radio dispatch channel, shall 

be provided for on-scene communications.

9.3.1.4 At a minimum, the tactical 

communications channel identified in 9.3.1.3 

shall be capable of analog simplex mode.

When fireground noise of high amplitude is 

introduced, the voice translation ability of the P25 

radio decreases and generates audio that is poor or 

not intelligible. These problems are worsened when 

the firefighter is speaking into the portable radio 

through an SCBA facepiece. Bone microphones, 

throat microphones and microphones in the 

facepiece minimize the interference caused by 

background noise by isolating the transmitted voice 

from background noise. Speaker microphones are 

subject to the same problems that are found with 

the microphone on the portable radio.

The configuration of the P25 vocoder is limited in 

its capability to translate the human voice in the 

presence of common fireground noise or through 

a facepiece. The studies performed by NIST and 

IEEE illustrate that digital radio intelligibility when 

talking through an SCBA facepiece is degraded. 

This can pose a safety hazard for fireground 

operations. To maintain safety, fire departments 

should consider using portable radios that 

incorporate analog modulation for operations 

where the firefighter is using an SCBA.

Radios using the P25 digital technology have 

performed well for other fire service functions, such 

as on emergency medical incidents and support 

functions on the fireground where an SCBA is not 

required, as well as law enforcement operations. 

The difficulties presented by the inability of P25 

radios to produce intelligible voice messages in the 

presence of fireground noise is a significant safety 

concern and should be considered seriously by 

public safety radio system designers and users.

P25 radio manufacturers recognized the need to 

filter or cancel background noise in the firefighting 

environment. Manufacturers took advantage of 

digital audio processing to remove the noise or 

use noise canceling using one microphone to 

detect the spoken audio and a second to detect the 

background noise. While these methods can work, 

it is important to note that this has increased the 

complexity of programming the radio. A missed 

check box when programming the radio can have 

detrimental effects. All new radio configurations 

must be thoroughly tested to ensure proper 

operation. The days of just buying an off-the-shelf 

speaker microphone and it working are gone.

Summary — Digital and Analog Radio

There are multiple radio types in use by the 

fire service. Mobile radios are usually mounted 

in vehicles. Mobile radios usually have better 

performance than portable radios. Mobile radios 

usually have better receivers and more powerful 

transmitters. Mobile radios used in trunked radio 

systems may or may not have more powerful 

transmitters. Portable radios are hand-held 

radios powered by rechargeable or replaceable 

battery packs. They usually have an external 

rubber antenna attached to the top of the radio. 

Portable radios have power limitations and suffer 

performance degradation based on where the user 

operates from and where the radio is worn. Base 

station radios are located at fixed locations, and 

usually are powered by AC utility power. Base 

station radios generally are higher in performance 

than mobile and portable radios. Repeaters are 

similar to base stations, but they can transmit and 

receive at the same time, retransmitting the signal 

received by the receiver. Repeaters are used to 

extend the coverage of portable or mobile radios.

Analog radios have been in use since the invention 

of voice radio in the early 1900s. The type of 

analog radio used today was invented in the 1930s 

to improve on the older radio’s poor immunity to 

noise. These radio systems use FM to modulate the 

transmitted signal with the user’s voice. 

To improve audio quality and spectrum efficiency, 

radio manufacturers introduced digital radios. 

Digital radio also provides a pathway for the FCC 

to improve efficiency and to meet the increasing 

requests for the spectrum. 
Voice Radio Communications Guide 24 for the Fire Service

P25 digital radios have different performance 

characteristics from analog radios. Digital radio in 

some environments provides clear voice with no 

background noise. The fire service environment is a 

challenging environment to operate in, and digital 

radios have performance degradation in several 

areas. The specific areas to be concerned with are:

•	 Radio use with an SCBA.

•	 Intelligibility in a high-noise environment.16,17

•	 PASS device.18

•	 Vibrating low-air alarms.

•	 Feedback.

Fire departments need to consider the performance 

differences between digital and analog 

technologies when researching new trunked 

communications systems. 

An analog simplex channel is a requirement in 

NFPA 1221 (2013 edition). The availability of 

analog simplex channel(s) for firefighting 

applications when the firefighter is using an SCBA 

is vital. Local fire departments need to test all 

elements of the communication system to ensure 

reliability (SCBA, radios, and any accessories such 

as speaker microphones, in-mask communications 

systems, etc.).

NFPA 1221 (2013 edition) requires a tactical analog 

channel for on-scene communications.

9.3.1.3 A communications radio channel, 

separate from the radio dispatch channel, shall 

be provided for on-scene communications.

9.3.1.4 At a minimum, the tactical 

communications channel identified in 9.3.1.3 

shall be capable of analog simplex mode.

The P25 standard continues to be the most common 

radio platform and will be into the foreseeable 

future. P25 systems offer a common radio language 

that provides a path to interoperability, but as 

with any system, interoperability has to be part of 

the plan.

16 Position Paper — Background Noise and Radio Performance, http://content.motorolasolutions.com/promo/sayitloud/

FRI_Paper_RO-99-2169_3.pdf.

17 NTIA Technical Report TR-08-453 Intelligibility of Selected Radio Systems in the Presence of Fireground Noise: Test Plan and 

Results, http://www.its.bldrdoc.gov/publications/2490.aspx.

18 National Public Safety Telecommunications Council (NPSTC) Brief — August 2008: International Association of Fire Chiefs 

Investigate Fireground Noise and Digital Radio Transmissions.
Section 4 | 25 Conventional 

Radio Systems

SECTION 4 — 

Conventional Radio Systems

There are a wide variety of radio systems in 

use today. There are simple systems that use a 

conventional analog repeater to complex trunked 

systems that employ the latest technologies. 

Conventional systems are generally categorized as 

nontrunked. Conventional systems are not computer 

controlled systems that require data infrastructure 

and controllers to manage radio traffic. Trunked 

systems, on the other hand, do require data 

infrastructure, and the portable units on a trunked 

system are infrastructure dependent. It is important 

that users of the system understand how the 

system works. This does not mean that they need 

to know the technical details of the system, but 

how to make it or adjust it to achieve reliable 

communications. In today’s world, most of us carry 

a mobile communications device, either a cellphone 

or smartphone. We may not understand what code 

division multiple access (CDMA), FDMA, 1XRTT, 

3G or 4G are, but we do use these systems and are 

able to make these systems work for us. An example 

would be walking inside of a building, and your 4G 

indication is absent, and the signal level indicator 

has one bar. You know that these indications mean 

that you need to move to an area with better 

cellular coverage. It has become second nature to 

us, and we need to have the same comfort level 

with the radio systems when we do the dangerous 

work of firefighting. The following sections 

describe some typical system configurations. Each 

and every system can vary based on how the 

system is programmed or how the portable radios 

are programmed. It is incumbent on us to train 

firefighters on the operational capabilities and 

limitations of these systems and their ability to 

provide reliable communications. 

Direct and Repeated Radio Systems

Radios communicate when the transmitter sends out 

a signal that is received by one or more receiving 

radios. When the signal is received from the radio 

initially transmitting the signal, the communication 

is direct. (That is, there is no intervening radio or 

system.) When one radio transmits and the other 

radios receive, this type of communication is known 

as simplex communication. In a repeated system, 

the portable radio transmit frequency is received 

by the repeater and retransmitted on the portable 

receive frequency at a higher power to extend range 

or increase penetration. 

Direct/Simplex Communications on the 

Fireground

Using simplex communications maintains positive 

communications between the IC, exterior on-scene 

units, and interior units without the reliance on 

exterior communications systems. Maintaining 

positive communications is especially important 

in “mayday” situations. When users on simplex 

radios are deployed to the interior of a structure, 

they create a radio receiver network. As more and 

more radios move into the structure, the strength 

of the network increases. If Engine 1 calls mayday, 

the probability of another radio on the interior 

receiving the transmission is high. If the mayday is 

not heard by the IC, another radio operator on the 

interior can act as a human repeater to repeat the 

message to the IC. In addition, the number of radios 

in a structure creates redundancy, whereas reliance 

on a single repeater or trunked system creates a 

single point of failure. Simplex communications 

allow direct communications with the initiator of 

the mayday and other crews on the fireground.

This is an example of direct/simplex 

communications with no infrastructure (Figure 

4.1). This means that there is no infrastructure to 

support receiving and transporting the fireground 

communications to the dispatch center, and without 

remote transmitters, the dispatch center is not able to 

transmit to the fireground. When the radios involved 

in direct communication are portable radios, the 

communication distance typically is limited to a 

few miles; for mobile radios the distance can be 

50 to 100 miles. Often this is referred to as “lineof-sight communication,” and this makes direct/

simplex radio communication most suitable for 

tactical use by units on an incident scene. Command 

systems that use these types of channels often have 

a command channel. In this type of system, the 

dispatch center monitors the command channel and 

the IC relays the relevant information received on the 

direct/simplex channel onto the command channel.
Voice Radio Communications Guide 26 for the Fire Service

Figure 4.1. Direct/Simplex Without Transmit/Receive Infrastructure

The cloud represents the maximum transit range of the portable radio.

Dispatch Center

Out of Receiver Range

Pump 1

Receives

E-4

Receives E-1

Transmits

E-2

Receives

E-3

Receives

Pump 3

Receives

The direct communication method is the simplest 

form of radio communication and is easily 

affected by terrain blocking, including man-made 

structures such as buildings. If an obstruction 

is between the transmitting and receiving 

radios, communication may not be possible. 

Users must be aware that some buildings due 

to size or construction cause communications 

difficulty. Many jurisdictions place warnings in 

computer-aided dispatch (CAD) systems to alert 

users of structures with known communications 

difficulties. Users can be advised to use human 

repeaters to communicate to the IC. Additionally, 

awareness on the fireground is important; if a 

communication attempt to the IC from the interior 

is heard and the IC does not answer, that might 

be a cue to relay the information. The short-range 

nature of direct communication also allows one 

radio channel used by one communicating group 

to be reused by another group further away. If the 

second group is far enough away that it does not 

hear the first group’s communications, then the 

channel can be reused. This minimizes the number 

of channels needed by an agency.

When a radio system must cover a larger area, 

or when terrain or other obstructions limit the 

distance a system can cover, additional equipment 

is needed to overcome these limitations. 

Receiver Voters — Improve Field Unit to 

Dispatcher Communications

Dispatch centers connected to high-powered 

transmitters provide the dispatch center with 

talk-out capability. Transmitters are elevated to 

achieve better line-of-sight communications with 

the service area. High-powered transmitters ensure 

that the dispatch center transmissions are heard 

throughout the service area and provide some level 

of in-building coverage (Figure 4.2).
Section 4 | 27 Conventional 

Radio Systems

Figure 4.2. Direct/Simplex With Transmitter/Receiver Infrastructure Dispatch Center Transmitting

The dispatch center’s high-power transmitter

allows all radios on the fireground to receive.

Site 3 Receive Audio

Site 2 Receive Audio

Site 1 Receive Audio

E-4

Receives

E-2

Receives

E-1

Receives

E-3

Receives

Pump 3

Receives

Receive

Site 1

Receive

Site 2

Receive

Site 3

Site 3 Voted Best Audio

Routed to Dispatch Center

Pump 1

Receives

Portable radios have limited power and cannot 

always transmit a signal strong enough to 

reach the transmitter sites. To provide a more 

balanced system, receivers are networked together 

throughout the service area in a receiver voter 

system (RVS) (Figure 4.3). Comparison of the 

received audio signal takes place in a receiver voter. 

The receiver voter and its network of receivers are 

referred to as the RVS. The RVS usually is located 

at the dispatch center. The receiver voter compares 

the audio from all receivers and routes the audio 

from the receiver with the best audio quality to 

the dispatcher. This type of system provides very 

reliable fireground communications and supports 

fireground simplex channels.
Voice Radio Communications Guide 28 for the Fire Service

Figure 4.3. Direct/Simplex Communications With Transmit and Receive Infrastructure Portable Transmitting

Site 3 Receive Audio

Site 2 Receive Audio

Site 1 Receive Audio

E-4

Receives

E-2

Receives

E-3

Receives

Pump 3

Receives

Receive

Site 1

Receive

Site 2

Receive

Site 3

The cloud represents the maximum transmit range of the portable radio.

Site 1 Voted Best Audio

Routed to Dispatch Center

Pump 1

Receives

Dispatch

Center

E-1

Transmits

Repeaters — Improve Field Unit to Dispatch 

and Off-Scene Units

Receiver voters are one solution to get 

communications from a radio user to the dispatch 

center, but another solution is needed to get 

the communication to other radio users. One 

type of system that can solve this problem is a 

repeated radio system (Figure 4.4). Repeated 

radio communication, also known as half duplex 

communication, uses two RFs for communication. 

The transmitting radio transmits on Frequency 1 

(F1), and that signal is received by the repeater. 

The repeater then repeats the transmission on 

Frequency 2 (F2), and this signal is received by the 

receiving radio. By locating the repeater on a high 

building or mountain, the range of transmissions 

from the transmitting radio can be more than 

doubled and can reach over obstacles effectively.
Section 4 | 29 Conventional 

Radio Systems

Figure 4.4. Repeater System — Portable Transmitting — Fireground Communications

Pump 1

Receives F2

Pump 3

Receives

E-2

Receives

F2

E-3

Receives

F2

E-1

Transmits

on F1

Repeater Maximum 

Range

Maximum Range 

of Portable Dispatch Center

Receives F2

Repeater receives low power signal on F1 

from E-1 portable and retransmits on F2 at 

high power to extend range. Portables on 

fireground are not in direct communication.

Another solution to improving communication 

between field units inside buildings or tunnels and 

dispatch and off-scene units is the bidirectional 

amplifier (BDA). BDAs can be used with half 

duplex radio systems to extend coverage from 

inside the structure to outside the structure and 

vice versa, but BDAs do not operate with simplex 

radio systems. BDAs are discussed in more detail in 

Section 5 — Trunked Radio Systems.

The significant operational difference between 

direct and repeated communications is that with 

direct communication, the transmitting radio’s 

signal only needs to reach other radios directly 

on the incident scene. With a repeated system, 

the signal must reach the closest repeater location, 

which may be much further from the incident than 

the receiving radios.

Figure 4.5 shows a method to overcome this 

limitation. If unit E-1 is unable to communicate 

with other units on the fireground using the 

repeater system, E-1 can switch to talk-around 

mode on the radio. This mode allows the unit to 

transmit in direct mode to other radios on the 

fireground and receive from the units in either 

direct or repeated mode. Since the radio is not 

able to reach the repeater, the dispatch center 

cannot hear the radio, although other radios on the 

fireground can hear the unit. A unit that switches 

to talk-around should announce this immediately 

so other units know that they also may need to 

switch to communicate with the isolated unit.
Voice Radio Communications Guide 30 for the Fire Service

Figure 4.5. Repeater System — Portable Transmit Talk-Around — Fireground Communications

Pump 1

Receives F2

Pump 3

Receives F2

E-1

Transmits F2

Receives F2

E-2

Transmits F1

Receives F2

E-3

Transmits F1

Receives F2

Receive F1

Transmit F2

Repeater Maximum 

Range

Maximum Range 

of Portable Dispatch Center

1. E-1 is unable to communicate with repeater and changes

 channels to talk-around channel F2. This is the repeater

 output frequency.

2. Other units on the fireground will hear E-1 but need

 to go to F2 to communicate with E-1.

3. Dispatch center unable to receive due to limited range 

 of portable

Simulcast Transmitter Systems 

When a radio system must cover a large area but the 

number of available frequencies is limited, a simulcast 

transmitter system may be the solution (Figure 4.6).

With this system, multiple transmitters simultaneously 

transmit on the same frequency. The transmitters 

must be precisely synchronized so that the signals 

they transmit do not interfere with each other.

In addition, the audio source sent to the transmitters 

must be synchronized so that the radio user hears 

the same signal from each transmitter. The system 

consists of a simulcast controller and two or more 

simulcast transmitters. The advantages of a simulcast 

system are the coverage of a large area, with high 

signal levels throughout the area, while using only a 

single frequency.
Section 4 | 31 Conventional 

Radio Systems

Figure 4.6. Simulcast — Dispatch Center Transmit — Fireground Communications

Site 1

Dispatch Center

Site 3 Transmit Audio

Site 2 Transmit Audio

Site 1 Transmit Audio

E-4

Receives

from Site 1

E-2

Receives

from Site 2

E-1

Receives

from Site 3

E-3

Receives

from Site 2

Pump 3

Receives

from Site 1

Transmit/Receive

Site 3

Pump 1

Receives

from Site 3

Control

Equipment

Transmit/Receive

Transmit/Receive

Site 2

Transmit Audio

Alerting

Many users of conventional analog systems use 

paging as a method of alerting personnel or 

fire stations of an incident or other important 

information. In an analog system, the use of 

two-tone paging accomplishes this. This feature 

has proven to be a low cost method of alerting 

for professional and volunteer firefighters. 

Unfortunately, digital radio systems cannot pass 

the tones required for two-tone alerting. The use 

of commercial paging services may be required 

to provide paging services in digital or trunked 

systems. Recently, companies are providing 

applications for smartphones that provide the ability 

to notify smartphone users using commercial data 

services, if the users’ dispatch system feeds the 

application with the required data. You must be 

aware that these notifications may not happen in 

real time and may be delayed by a few seconds to 

minutes depending on delays in the commercial 

data service. If the commercial data system is 

congested during a disaster, the delays may be 

significant. Data and phone congestion were 

identified as a weakness in the Boston Bombing19

and the Virginia earthquake.20

Summary — Conventional Radio Systems

There are a wide variety of radio systems in 

use today. There are simple systems that use a 

conventional analog repeater to trunked systems 

that employ the latest technologies.

Direct Communications

Radios using direct communications are not 

dependent on infrastructure to communicate 

to other units on the fireground. Direct 

communications are limited in range, so they are 

commonly used as fireground tactical channels. 

19 April 2013, http://www.huffingtonpost.com/2013/04/15/boston-cell-service_n_3087341.html.

20 August 2011, http://www.pcmag.com/article2/0,2817,2391635,00.asptrunked-radio-system-problems/.
Voice Radio Communications Guide 32 for the Fire Service

Using simplex communications maintains positive 

communications between the IC, exterior on-scene 

units, and interior units without the reliance 

on exterior communications systems. There are 

limitations in range due to the portable radios 

having limited power. Awareness on the fireground 

is important; if a communication attempt to the 

IC from the interior is heard and the IC does 

not answer, that might be a cue to relay the 

information. Dispatch centers can employ receiver 

voters and high-powered transmitters to allow 

reliable communications with fireground units.

Repeaters

Provide wide area coverage for portable radios. 

The portable signal is received and retransmitted 

at a higher power to extend the range. 

Communications with repeaters are dependent 

on the repeater as part of the communications 

infrastructure. Coverage to the repeater can be 

degraded when operating on the interior of a 

building. Use of talk-around allows users to use 

the output frequency to bypass the repeater. This is 

referred to as a talk-around frequency.

Simulcast

Simulcast systems are employed when trying to 

cover a large service area. Simulcasting allows the 

dispatch centers to transmit simultaneously from 

multiple transmitters that cover a larger geographic 

area. The advantages of a simulcast system are 

the coverage of a large area, with high signal 

levels throughout the area, while using only a 

single frequency.

Alerting

Many users of conventional analog systems use 

paging as a method of alerting personnel or 

fire stations of an incident or other important 

information. In an analog system, the use of 

two-tone paging accomplishes this. Unfortunately, 

digital radio systems cannot pass the tones required 

for two-tone alerting. The use of commercial 

paging services may be required to provide paging 

services in digital or trunked systems.
Section 5 | 33 Trunked 

Radio Systems

SECTION 5 — 

Trunked Radio Systems

Trunked radio systems are complex radio systems 

that were developed to improve the efficiency of 

the use of available radio spectrum. In conventional 

(nontrunked) radio systems, an RF is dedicated to a 

single function or workgroup. When the RF is not 

in use, it cannot be used by another function or 

workgroup. Trunking borrows technologic concepts 

from telephone systems to assign RFs to active calls, 

improving the efficiency of frequency use. 

Like a conventional repeated radio system, trunked 

radios communicate with each other through 

two or more repeaters (Figure 5.1). In a trunked 

system, the radios often are known as subscriber 

units, and a voice communications exchange is 

known as a call. A basic trunked radio system has 

a system controller that controls the assignment 

of the repeaters, called voice traffic repeaters, to 

individual calls. The radios communicate with the 

system controller, for example to request the use of 

a voice traffic repeater, by sending data messages 

to the system controller on a special dedicated 

channel called the control channel. The system 

controller acknowledges these communications and 

sends information to the radios using the control 

channel as well. The radios also can communicate 

some information using the voice traffic channels 

after a call has been terminated.

Figure 5.1. Trunked Radio System — Dispatch Center Transmitting

Dispatch Center

Actual frequencies are assigned

dynamically by the control equipment.

Site 3 Transmit Audio

Site 2 Transmit Audio

Site 1 Transmit Audio

E-4

Receives

from Site 1

E-2

Receives

from Site 2

E-1

Receives

from Site 3

E-3

Receives

from Site 2

Pump 3

Receives

from Site 1

Pump 1

Receives

from Site 3

Transmit Audio

Control

Equipment Transmit/Receive

Site 1

Transmit/Receive

Site 2

Transmit/Receive

Site 32
Voice Radio Communications Guide 34 for the Fire Service

The voice traffic repeaters are shared among 

all users of the system. They also are known as 

resources. In complex systems that use encryption 

and dispatch consoles, other equipment is 

necessary for the operation of these features, and 

they are considered shared resources.

The radio industry uses the term “talkgroup” 

to distinguish among physical frequencies or 

channels used in conventional radio systems. This 

terminology often is confusing, since from the 

actual radio user’s point of view, a talkgroup and a 

conventional channel are the same; they are both 

communications paths. The distinction is made by 

the technologists to differentiate a physical channel 

or frequency from the logical channel or talkgroup.

The system controller and other parts of the 

trunked radio system maintain a log of all activity 

that occurs in the system, as well as statistical 

information on the operation of the system. These 

system logs can be used in the event of a suspected 

anomaly in the operation of the system to help 

determine the cause.

Basic Trunked Radio Operations

Radio On/Off — Registration/Deregistration/Talkgroup 

Affiliation

When a trunked radio is powered on initially, it 

begins operation by telling the system controller 

that it is active, along with the talkgroup currently 

selected on the radio, using the control channel. If 

the registration is successful, the radio is registered 

on the system and now can receive and transmit; if 

the registration is not successful, the radio will not 

operate on the system.

Any time that the radio is powered on and the user 

changes talkgroups, the radio will tell the system 

the new talkgroup selection, and the system will 

confirm the selection. In this way, the system 

tracks the currently selected talkgroup for all radios 

registered on the system.

When the radio is switched off by the user, the 

radio transmits a message to the system controller 

telling the system to deregister the radio. The radio 

then will wait for an acknowledgment from the 

system before actually powering off.

Talkgroup Call

When a radio user wishes to transmit on a 

talkgroup, he or she presses the PTT switch, just 

as with a conventional radio. The radio then sends 

the trunking system a request to transmit, using 

the control channel. The trunking system checks 

to see if the requested talkgroup is free and if there 

are available voice traffic repeaters. If these are true, 

then the system assigns a voice traffic repeater to 

the call and instructs all radios with the talkgroup 

selected to change frequencies to the voice traffic 

repeater frequency. The system also sends a 

message to the requesting radio telling it that it 

may proceed with its transmission. This causes 

the user’s radio to play a tone sequence (typically 

three short beeps) to tell the radio user that he 

or she may proceed with the transmission. The 

radio’s transmission is received by the voice traffic 

repeater and retransmitted to the other radios on 

the frequency (Figure 5.2).
Section 5 | 35 Trunked 

Radio Systems

Figure 5.2. Trunked Radio System — Portable Radio Transmit — Fireground Communications

Dispatch Center

Site 3 Transmit

P25 Data

Site 2 Transmit P25 Data

Site 1 Receive and Transmit P25 Data

E-2

Receives E-1

P25 digital

message from

system

E-1

Transmits to

system in

P25 digital

E-3

Receives E-1

P25 digital

message from 

system

Pump 3

Receives E-1

P25 digital message

from system

1. Transmit/Receive Site 1 receives 

 E-1 P25 digital message and routes 

 E-1 data to system control equipment.

2. System sends P25 digital transmit 

 message to Site 1.

Actual frequencies are assigned

dynamically by the control equipment:

E-4

Receives E-1

P25 digital 

message

from system

Pump 1

Receives E-1

P25 digital message

from system

Receive Audio

Transmit/Receive Site 3

Transmits E-1 P25 digital

message

Transmit/Receive Site 2

Transmits E-1 P25 digital

message

Transmit/Receive Site 1 Control

Equipment

Receive Audio

If there are no voice traffic repeaters available for 

the call, the system will place the request in a busy 

queue in order of priority, send a busy message 

to the requesting radio, and wait a short time for 

resources to become available. If the resources 

become available, the transmission proceeds. If the 

resources do not become available before the wait 

time expires, the system transmits a message to the 

requesting radio telling it that the request failed. 

The radio will play a tone (commonly called a 

“bonk”) to the user, indicating the failure.

Call Disconnection

When the transmitting user is finished with 

the transmission, he or she will release the PTT 

switch. This causes the radio to send a message on 

the control channel telling the system that it can 

release the resources assigned to the transmission. 

Depending on the configuration of the talkgroup, 

the system either waits a few seconds for additional 

transmission requests before releasing the resources 

or it releases the resources immediately. Once the 

timeout is reached, the system tells all radios on 

the talkgroup to change channels to the control 

channel and releases the voice traffic repeater 

for use for other requests. If another request is 

received before the resources are released, then the 

system immediately grants the requesting radio’s 

transmission request and does not need to tell the 

other radios to switch frequencies.

Designing a Trunked Radio System

Trunked radio systems are complex combinations 

of radio equipment with computer control systems 

and require skilled engineering to design an 

effective system properly. Trunked radio systems 

have been in use for over 20 years, and the 

manufacturers of these systems are fully capable 

of delivering a system that is technically reliable. 

These systems are designed and manufactured to be 

as reliable as conventional radio systems. Trunked 

systems can be deployed in either analog or digital 

technologies, depending on the frequency band 

they are deployed on. 
Voice Radio Communications Guide 36 for the Fire Service

The design of the overall system, including 

the system’s coverage and capacity, involves 

considerable effort to produce a communications 

system that is effective for the community and 

agencies that will use it. The system must have 

the capacity to accommodate the needs of all of 

the users of the system and must provide usable 

coverage in all of the agency’s service areas. It 

is critical to have the end users involved in the 

specification of these parameters.

Capacity Design

The capacity of a trunked radio system is the amount 

of communications traffic that the system can 

support in a given amount of time. The frequencies 

in the trunked radio system are shared among users 

and assigned to conversations, as necessary. If there 

are more talkgroups (i.e., channels) than there 

are frequencies, which is often the case, then the 

potential exists for calls to be blocked.

It is most desirable for public safety users to never 

have a call blocked, although this never can be 

guaranteed in a system with shared frequencies. 

Manufacturers use statistical models to estimate 

the traffic presented to the trunked radio system. 

These models are based on historical traffic 

information collected from other customers, along 

with predictions of usage based on experience 

with similar agencies. This historical information 

may not represent operations in your agency. In 

addition, the traffic information may not represent 

peak loading but only average loading. If the system 

is designed and constructed for average loading, 

and performs as designed with average loads, then 

it may not be able to provide adequate service 

when confronted with abnormally high loads. 

These high loads can occur during natural disasters 

or large-scale incidents such as train derailments, 

plane crashes, or multialarm fires.

An important concept is that all users of a trunked 

radio system affect the system’s performance and 

can affect other users. The channels used by the 

system are shared among all users of the system, 

and like any other shared resource, all users must 

be aware of their impact on other users and must 

act accordingly. For example, some users may 

talk excessively and use the trunking system to 

discuss issues best discussed face to face or on 

the telephone. Proper user education and the 

establishment of a formal communications order 

model can help prevent unnecessary system load.

Site capacity is determined by the number of radio 

channels on a site. For instance, a low capacity site 

might have five radio channels. The five-channel 

site allows four simultaneous voice calls, and 

the fifth channel is the control channel (FDMA 

system). A high capacity site in the system could 

have 20 channels that would allow 19 simultaneous 

voice calls and one control channel. If four users 

being serviced by the low capacity site monitor 

high volume traffic on four separate talkgroups in 

the high capacity site, the low capacity site can get 

busied out due to the users “dragging traffic” onto 

the low capacity site. System administrators must 

work with operational personnel to determine the 

number of wide-area talkgroups that are allowed 

on the system. Wide-area talkgroups must be 

used appropriately to minimize busies caused by 

dragging unwanted traffic into low capacity sites. 

Other talkgroups may be restricted to specific sites 

in the system to minimize dragging traffic into 

unwanted areas. Site restrictions can be done by the 

user or the talkgroup. This gives the administrators 

flexibility in being able to meet the needs of 

responders and maintaining system performance. 

Coverage Design

Trunked radio systems that are for firefighting 

operations must be designed to provide radio 

coverage inside buildings. System manufacturers 

estimate what the system will require in terms of 

radio tower sites and other system components 

to provide coverage on the street. This becomes 

the base signal reference level and is referred to as 

zero decibel (dB). In-building coverage levels are 

dictated by the construction of the buildings from 

which the users need to communicate. The heavier 

the construction, the higher the signal level needed 

to provide RF penetration into the structure.

During system design, the service area is analyzed, 

and geographic areas are categorized based on the 

structures within them (Figure 5.3). For example, 

the central area of a city may have high-rise 

structures that require the highest penetration 

signal levels. The area surrounding the high-rise 

district may consist of midrise and warehouse 
Section 5 | 37 Trunked 

Radio Systems

Figure 5.3. Coverage Map

structures requiring less signal level to penetrate 

the structure. In suburban areas, even less signal 

generally is required to communicate on the 

interior of a structure. Areas with the greatest RF 

penetration demand will have a higher number of 

radio sites than areas with lesser penetration. When 

a building such as a hospital or school is built in a 

predominately suburban area, the radio system will 

not provide in-building communications because 

the area was designed for residential structures. 

Interior radio system coverage is dependent on 

the ability of the system designer to estimate 

the signal loss accurately for each building type. 

During testing performed by NIST, building 

losses as high as 50 dB were found in a 14-story 

apartment building.21 For reference, a 50 dB loss 

equals 1/100,000th of the transmitted signal. The 

actual RF losses encountered are often much higher 

than the standard recommendations that system 

manufacturers use. This can result in marginal 

in-building communications in many structures.

System manufacturers and designers will never 

guarantee, and it is impractical to expect, 100 

percent coverage. It is impossible to guarantee 

100 percent coverage in any city. There is always 

some corner of a building that a radio system does 

not cover. The problem with no coverage from a 

trunked system is very different from a simplex 

area. In a trunked system, no coverage means no 

communications. 

Since trunked radio systems can have several levels 

of RF penetration, the users of the system need to 

be aware that a particular building type in one area 

of the system may have communications, while 

the same building in another area may not have 

communications. 

Coverage Enhancement Devices

The following devices are coverage enhancers 

for trunked and conventional systems. The same 

theory applies in both trunked and conventional 

applications. They receive a weak signal and 

retransmit at a level that allows the system to 

capture the signal. The coverage enhancement 

devices have been placed in this section due 

to being discussed in most trunked system 

deployments. Trunked systems commonly use 

these devices to achieve coverage requirements. 

Bidirectional Amplifiers

To overcome system in-building coverage 

difficulties, BDAs often are used to rebroadcast the 

trunked system in buildings (Figure 5.4). BDAs 

also can be used with conventional duplex radio 

systems. There are many types of BDAs; all require 

electrical power and some type of antenna system. 

The antenna systems are often installed in the 

plenum spaces of commercial structures. Most BDA 

systems include battery backup power to keep them 

operational if a loss of commercial power occurs. 

BDAs work well for incidents such as Emergency 

Medical Services (EMS) calls and law enforcement 

incidents where there is no fire involvement in 

the building or building systems. In a structure 

with active fire, the building and building systems 

are affected directly. The building environment 

changes with the introduction of fire. Temperatures 

rise, and particulate matter is suspended in the 

atmosphere. Firefighter actions to eliminate the 

fire can also have a detrimental effect on BDA 

systems. As water is applied to the fire, steam is 

generated that may have an effect on electronic 

21 Radio Propagation Measurements during a Building Collapse: Applications for First Responders, Conclusions and Discussion 

p. 3, Christopher Holloway, Galen Koepke, Dennis Camell, Kate A. Remley and Dylan Williams.
Voice Radio Communications Guide 38 for the Fire Service

equipment. Acids are formed when moisture mixes 

with suspended materials. These acids can cause 

intermittent failure of exposed electrical contacts 

over time. As with all electronics, BDAs are subject 

to failure when exposed to high heat and moisture. 

Other actions taken during firefighting operations 

also could destroy the BDA system. Firefighters 

checking for extension using pike poles may 

inadvertently tear the BDA antenna system down, 

rendering the BDA useless and causing loss of 

communications inside the building.

Figure 5.4. In-Building Communications System

BDA

Coax Cables

Donor (Roof) ANT

Antenna Taps

or Splitters

Indoor Antennas

BASIC RF DISTRIBUTION

SYSTEM COMPONENTS

Identifying the buildings that need BDAs and 

installation of the equipment is a monumental 

task, especially in fast-growing metropolitan areas. 

BDAs, like any other transmitters, require periodic 

maintenance to keep the equipment operating at 

peak performance. To maintain BDAs in a system 

requires staffing and technical expertise to keep the 

equipment operating properly. As building density 

increases in a given area, a building that did not 

need a BDA when constructed may need one as it 

is surrounded by new construction. This requires 

periodic RF surveys to determine if new BDAs are 

needed. In 2013, the FCC made changes to the Part 

90 rules that require installation by FCC licensees 

and qualified installers. The revision to Part 90 

also requires registration of signal boosters. These 

actions were taken to control harmful interference.22

Many municipalities have developed fire codes that 

require installation of this equipment. The codes 

often require BDAs when a building exceeds some 

square footage value, during additions increasing 

square footage by some percentage of the original, 

or in all-new construction. The 2012 International 

Fire Code (IFC) requires that “All new buildings 

shall have approved radio coverage for emergency 

responders within the building based upon 

the existing coverage levels of the public safety 

communication systems of the jurisdiction at the 

exterior of the building.”23 In addition to requiring 

radio coverage, IFC, Section 510 specifies technical, 

installation and maintenance requirements for 

in-building public safety radio coverage systems.

Figure 5.5. In-Building Distributed Antenna System

Antenna

Directional Yagi antenna

Fiber distribution

unit (remote)

Fiber distribution hub

Service provider

head-end

BDA

Low Loss Coaxial Cable

Fiber Optic Cable

Drawing credit: http://www.l-com.com/what-is-a-distributed-antennasystem-das

An array of antennas is installed on each floor in 

some installations of BDAs (Figure 5.5). These 

systems often provide better coverage due to having 

more antennas on each floor to bring the signal 

in for retransmission or redistribution inside. The 

Distributed Antenna System (DAS) approach is 

commonly deployed in complex structures, such 

as high-rise buildings or airport terminals. In 

Figure 5.5, each floor has a DAS that is connected 

by low loss coaxial cable. The coaxial cable is 

22 http://wireless.fcc.gov/signal-boosters/part-90-boosters/index.html.

23 IFC 2012 First Printing, Section 510.
Section 5 | 39 Trunked 

Radio Systems

terminated on each floor at a fiber distribution 

unit. Fiber optic cables run between each floor 

to connect the fiber distribution units. All of the 

fiber distribution units are connected to a fiber 

distribution hub. The hub is connected to the RF 

head-end and to the BDA and then by coaxial 

cable to the exterior antenna. These systems can 

be very complex, and their survivability in a fire is 

dependent on the standards or codes that they are 

built to.

Vehicular Repeaters

Some municipalities have recognized the weaknesses 

in BDA systems and have installed vehicular 

repeaters (VRs) on fire apparatus to provide inbuilding coverage that is suitable for firefighting 

operations. Each apparatus is equipped with a VR 

that is activated manually prior to entering the 

involved structure. These repeaters are operated 

in the repeater mode, meaning that the users 

transmit from the portable radio, it is received by 

the repeater, and then retransmitted to the other 

portable radios on the fireground (Figure 5.6). The 

VR retransmits all radio traffic from the repeater 

(transmit and receive) onto the trunked system 

talkgroup. Radios that are not in range of the VR are 

capable of bidirectional communication through the 

wide-area coverage provided by the trunked system.

In the repeater mode of operation, fireground 

radios are not communicating directly with 

one another. The radios are dependent on the 

repeater for communications. If an interior crew 

encounters an area where it does not have repeater 

coverage, it can switch to a talk-around channel to 

communicate directly with other interior crews. 

If the unit on talk-around can hear the repeater 

but the repeater does not receive the transmitted 

traffic, the unit on talk-around can transmit — and 

on the repeater output with units in direct range 

on the repeater channel. Units on the repeater 

channel will be receiving the transmissions directly 

Figure 5.6. Trunked System — Portable Transmit — Vehicular Repeater

Dispatch Center

Site 3 Transmit/

Receive P25 Data

Site 2 Transmit/Receive P25 Data

Site 1 Transmit/Receive P25 Data

E-4

Receives E-1 

analog on F2 

from VR

Talkgroup

call

Talkgroup

call

E-2

Receives E-1

analog on F2

from VR

Portable

Receives E-1 from Trunked

System Transmit/Receive Site 2

E-1

Transmits

on duplex

analog F1

E-3

Receives E-1

analog on F2

from VR

Control

Equipment

Receive Audio

from VR

Transmit/Receive Site 3

Receives talkgroup

call from VR

Transmit/Receive Site 2

Receives talkgroup call

from VR

Transmit/Receive Site 1

Receives talkgroup call

from VR

1. Receives E-1 analog on

 F1 and repeats on F2.

2. VR repeats fireground analog

to trunked system talkgroup

 for wide-area coverage.

• The dispatch center communicates

with the fireground using a trunked

system talkgroup.

• The VR repeats the dispatch

center traffic to the analog

duplex channel.

Pump 1 VR
Voice Radio Communications Guide 40 for the Fire Service

from the talk-around unit. When the units on 

the repeater channel respond, they will transmit 

through the repeater, and the talk-around unit will 

receive the traffic on the repeater output channel. 

If the unit on talk-around cannot transmit or 

receive traffic from the repeater, the unit on 

talk-around will only be able to transmit to units 

within range of the portable. The units on the 

repeater channel will receive the talk-around 

traffic, but since the talk-around unit cannot hear 

transmissions from the repeater, the units on the 

repeater channel will be required to change to the 

talk-around to have bidirectional communications.

The other interior crews need to change to the 

talk-around channel to communicate with the 

out-of-range crew. When talk-around is used, the 

unit on talk-around can hear radio traffic through 

the repeater but cannot transmit to other units 

unless those units also change to talk-around. The 

talk-around function can cause some confusion 

unless the unit that switched to talk-around clearly 

communicates the channel change to other units 

on the fireground.

Other Trunking System Features

Trunked systems are feature-rich and can provide 

much more than just voice traffic. Some of the 

features greatly decrease the labor required to 

maintain and update fleets of radios. To maintain 

the ability to have voice traffic, these features must 

be accounted for in system design to build the 

capacity to maintain the reliability needed to carry 

the voice traffic.

Emergency Alarm

There are two different emergency features in 

trunked radio systems: emergency alarm and 

emergency call. When a radio user presses the 

emergency button on the radio, the radio switches 

to the control channel and transmits an emergency 

alarm message. This message is processed by the 

system, and an indication of the activation of the 

alarm is presented to any dispatchers using radio 

consoles. The benefit of the emergency alarm feature 

is that it is possible to send the alarm message even 

when all repeaters in the system are busy. Thus, even 

when the talkgroup is in use, an emergency alarm 

can be sent by a firefighter in trouble.

Emergency Call

An emergency call is similar to a normal talkgroup 

call or a multigroup call, but the radio initiating 

the call is in emergency mode after having its 

emergency button pressed.

Emergency calls are initially processed in the same 

way as talkgroup calls or multigroup calls. The 

difference in processing occurs when resources 

are not immediately available for assignment to 

the emergency call. If resources are not available, 

the emergency call can be processed in two ways: 

top-of-queue or ruthless preemption, depending on 

the configuration of the trunked radio system. 

If the system is configured for top-of-queue, the 

request for resources is placed on the busy queue 

in front of all other requests. When the resources 

become available, the emergency call is assigned 

the newly available resources immediately.

If the system is programmed for ruthless 

preemption, the request for resources is not queued, 

and instead, the voice repeater for the lowest priority 

existing talkgroup is reassigned to the emergency 

call. To accomplish this, the receiving radios on 

the existing lower priority call are instructed to 

terminate that call, and the radios on the emergency 

call are instructed to tune to the frequency of that 

voice repeater. Unfortunately, the transmitting radio 

on the lower-priority call cannot be instructed to 

terminate the call. This can cause the emergency 

radio to compete with the lower-priority radio, 

resulting in distorted audio or no audio. 

Radio Alerting

Individual radios can be alerted to notify the user 

of incoming traffic. Some agencies use this when 

dispatching units. A radio or radios assigned to 

a specific unit will be alerted much like a pager 

when traffic for them is inbound.

Location Services

Many trunked systems integrate the ability to 

receive location information from radios in the 

field if they are equipped with GPS. This feature 

allows tracking of units when they are receiving 

GPS signals from the satellites. This location service 

has severe limitations in the fire service due to loss 

of signal when entering buildings. 
Section 5 | 41 Trunked 

Radio Systems

Multigroup Call

A multigroup call is a call that transmits to two 

or more talkgroups simultaneously. The system 

can be configured to wait for all talkgroups 

in the multigroup to become available before 

initiating the call or configured to begin the 

call immediately, with busy talkgroups joining 

when their calls are complete. During the call, 

all associated talkgroups act as a single talkgroup. 

Because of this, after the initial multigroup 

transmission completes, a user in one of the 

associated talkgroups can call all users in the 

associated talkgroups. In a busy system, this 

can keep the multigroup call in progress for a 

significant amount of time, severely disrupting 

operational communications.

Dynamic Regrouping

The dynamic regrouping feature allows an 

authorized system administrator to assign a radio to 

a specific talkgroup remotely. The purpose of this 

feature is to allow multiple radios to be grouped 

together on a talkgroup for operational purposes. 

This feature is limited in function due to the 

potential delays while the radio is assigned to the 

new talkgroup. Because of this, few agencies use 

this for critical operations.

Over the Air Rekeying

Encryption allows the voice traffic to be 

unintelligible unless both the transmit radio 

and receive radio have a common key. While 

mentioned in the trunked section, encryption is 

an available option on conventional systems as 

well. Encrypted operations require the use of a 

“key” to decode scrambled signals. Trunked system 

operators that use encryption periodically change 

the keys to maintain security on the system. The 

changing of the keys requires that all radios that 

use the encryption key be changed or rekeyed. 

Changing keys or rekeying was labor intensive, 

requiring each radio to be individually rekeyed. 

Most contemporary trunked systems have over 

the air rekeying (OTAR) available for encrypted 

operations. The use of OTAR has greatly decreased 

the labor required to maintain and rekey the 

portable radios on a system. The rekeying process 

in older systems required that each and every radio 

on a system be manually rekeyed one by one. 

Over the Air Programming

The newest systems will soon be offered with over 

the air reprogramming. Again as with OTAR, over 

the air programming (OTAP) will allow updates 

to entire fleets of radios without the need to bring 

them to a radio technician. Some radios use Wi-Fi 

to provide the needed bandwidth to provide OTAP. 

In Wi-Fi-enabled radios, the radio uses the Wi-Fi 

connection for OTAP. This method of OTAP does 

not impact trunked radio system performance.

Short Message Service

Since the radios are digital, many trunked systems 

support sending short messages across the 

network. This has the possibility to send dispatch 

information over the network if the radios are 

equipped with a liquid-crystal display (LCD) screen.

Selective Disabling

This feature allows radios to be disabled if lost or 

stolen. Radios can be remotely disabled to maintain 

security of encrypted channels.

Private Call

The private call feature allows one radio to call 

another radio and to carry on a conversation 

without any other radios hearing the conversation. 

The radio user initiating the call must select the 

called radio from a list or know the numerical ID 

of the called radio. Some more advanced radios 

allow the user to change numbers in a cellphonelike phone book, making this feature more usable.

A problem with the private call feature is that it 

is very difficult to predict the capacity or loading 

impact of this feature during system design. When 

the system is in operation, high private call usage 

can cause other system users to experience more 

talkgroup busy signals than the design would 

predict. Some system operators prohibit the use 

of private call to eliminate the possibility of these 

calls affecting more critical operations.

Telephone Interconnect

The telephone interconnect feature allows system 

users to answer or make calls to telephone users 

from the user’s radio, similar to a cellular phone. 

The difference between telephone interconnects 

and a cellphone is that the trunked user cannot 

transmit and receive simultaneously. Telephone 
Voice Radio Communications Guide 42 for the Fire Service

interconnect was a much more valuable feature 

before the cellphone became commonplace. In 

addition, similarly to private call, it is difficult to 

predict telephone interconnect usage during system 

design. Telephone interconnect can have adverse 

effects on system capacity. 

Summary — Trunked Radio Systems

Trunked radio systems are the most complex 

of public safety radio systems. As with all radio 

systems, the coverage of the trunked radio system 

is the key to its safe operations for the firefighters. 

Users can live with systems that lack telephone 

interconnects, private calling, and paging, but 

they cannot operate safely inside a hazardous 

atmosphere with a radio system that does not 

provide reliable communications.

Basic Trunked Radio Operations

In trunked radio operations, the radios request 

functions of the system, such as requesting a 

voice call. These system requests require constant 

handshaking between all of the units in the system 

to operate.

The design of a trunked system is a very 

deliberate process that requires analysis of current 

communications requirements and forecasting 

what will be required in the future. When systems 

are being designed, these are some of the key 

elements to consider:

•	 Capacity.

– Number of users.

– Number of talkgroups.

– Peak traffic load. 

•	 Coverage.

– Geographic area.

– Levels of coverage.

- In-building penetration.

Coverage Enhancement Devices

While discussed in the trunked section, coverage 

enhancement devices can be used in other system 

types. BDAs are commonly used in trunked system 

deployments to achieve in-building coverage goals. 

The systems installed vary in complexity based on 

the building. An example of a complex installation 

might be a large airport. Simple installations might 

be installed to achieve coverage in a specific area 

of a building, such as a jail. VRs can repeat local 

signals from the fireground to a wide-area system, 

such as a trunked system.

Features

Trunked radio systems offer many functions and 

features not available in conventional systems. 

During system design, it is important to identify 

the features that will be used and plan for their 

implantation when the system is deployed. OTAR 

and OTAP are features that are extremely helpful 

in management of radios in the system. Some 

features can impact the performance of the system, 

or the feature may not work in the fire service 

environment.
Section 6 | 43

Portable Radio 

Selection 

and Use

SECTION 6 — 

Portable Radio Selection and Use 

General

The success of a fire service radio system project 

hinges on the performance of the portable radio. 

If the portable radio has poor performance, the 

end user relates it to the performance of the radio 

system as a whole. All the firefighter knows is that 

when the PTT was pressed, the communications 

worked or did not work. 

Manufacturers offer radios at different price points 

to meet market need. As with any other product, 

the options and performance levels increase with 

the cost. Usually there are three tiers of radios 

available. At the lowest level are nonruggedized 

radios meant for users who do not handle 

radios in a rough manner and do not operate 

in environmental extremes. The second level of 

radio is for the user who needs more reliability 

and performance features. The highest tier radios 

are focused on the public safety user. They offer 

the highest levels of performance and reliability 

and have the most options available. Radios with 

the most options are typically more complex and 

require appropriate training and reinforcement to 

maintain proficiency. At this level, the radios often 

are submersible and have intrinsically safe options. 

Submersible radios are a very worthwhile option 

for the fire service, considering the possibility of 

radios getting wet or exposed to steam. 

Ergonomics

Today’s radios are an integral part of firefighting and 

a key component of fireground safety. The form and 

fit of the radios for firefighting have not improved 

much over the past decade. Buttons and knobs have 

increased in size as compared to the radios of the 

1980s and 1990s, but firefighters have the same 

difficulties operating radios while in PPE. Radio 

knobs are still difficult to manipulate with a gloved 

hand, even though it is required as a component of 

NFPA 1221 (2013 edition) (Figure 6.1).

The radios of today can be programmed with 

hundreds of channels or talkgroups. The large 

number of channels/talkgroups has made “hard 

switches” that correspond with a channel/

talkgroup impossible. To select channels on radios 

with added channel capabilities requires LCDs and 

“soft keys” to provide access. In firefighting, the 

LCDs are not readable in smoky environments, and 

the soft keys cannot be pressed with a gloved hand. 

When programming the radio, take care to make 

firefighting radio channels easily accessible. 

Environmental Technical Standards

Radios are designed to operate in environmental 

ranges. The harsh environment of firefighting is 

hard on equipment and personnel. To provide 

reliable communications, it is common to purchase 

Figure 6.1. NFPA 1221 9.3.6.6: Portable radios shall be designed to allow channels to be changed while emergency 

response personnel are wearing gloves

(Photos courtesy Cody Worrell)
Voice Radio Communications Guide 44 for the Fire Service

ruggedized communications equipment. The 

technical specifications and testing protocols used 

to determine if a device is rugged can be confusing. 

Manufacturers use several testing protocols to 

determine if the device is “Public Safety Grade.” 

Some of the more common standards encountered 

are Military Standards (MIL-STD) and International 

Electrotechnical Commission (IEC) standards.

International Electrotechnical Commission 

Ingress Protection Codes

Ingress Protection (IP) codes are international 

standards that test for IP into an electrical 

enclosure. Manufacturers use this code to rate 

intrusion against solid objects from hands to dust 

and water in electrical enclosures. The rating 

consists of the letters “IP” followed by two digits. 

The standard is intended to provide an objective 

testing protocol to reduce subjective statements 

such as “waterproof.” The first digit represents 

the size of the object that is protected against, and 

the second digit represents the water protection. 

More detailed information on this standard can be 

found at www.iec.ch, International Electrotechnical 

Committee, IEC 60529.

Military Standards 

In the 1970s and 1980s, radios were manufactured 

to various industry standards for ruggedness 

and technical stability. In the 1990s, radio 

manufacturers adopted MIL-STD 810 as a standard 

for reliability and ruggedness. MIL-STD 810 

was developed by the military to provide an 

environmental test protocol that would prove 

qualified equipment would survive in the field. 

MIL-STD 810 is a test protocol written for the 

military environment, not the firefighting 

environment. The specification sheets often 

reference a letter designation behind the MIL-STD. 

The letter designation represents the revision level 

of the MIL-STD being tested to. The latest revision 

is MIL-STD 810 F. Earlier revisions of MIL-STD 810 

were generic up to revision C. Subsequent revisions 

became more tailored to the actual environment 

the equipment would operate in. Manufacturers 

sometimes only perform specific test components 

of the MIL-STD. For instance, an equipment 

specification may read “MIL-STD 810 F for water, 

dust and shock resistance.” When we see MIL-STD 

810, we assume that the equipment is ruggedized 

and will survive the firefighting environment. We 

need only look to the temperature specification to 

see that this is questionable. MIL-STD 810F actually 

has two temperature specifications depending on 

where the equipment is to be used (Table 6.1).

The table shown is the high temperature table 

from MIL-STD 810F. A similar table is included 

in MIL-STD 810F for low temperatures. Most 

manufacturers test to the “Basic Hot” and “Basic 

Low” temperature levels. This temperature range 

is from approximately minus 30 C to 60 C (minus 

22 F to 140 F). These temperature extremes do 

not replicate the environments that firefighters 

encounter. Radios that are available today are still 

manufactured to this specification.

How Many?

After defining the technical and operational 

requirements of the radio, the number of radios 

needed has to be determined. Departments have to 

identify who needs radios. A portable radio for each 

firefighter provides the highest level of safety. In 

addition to firefighters, radios for support and other 

fire department functions should be considered. 

Table 6.1. Military Standard 810F High Temperature Table

Design Type Location Ambient Air C (F) Induced C (F)

Basic Hot Many parts of the world, extending outward from hot category of the 

United States, Mexico, Africa, Asia, and Australia, southern Africa, 

South America, southern Spain, and southwest Asia.

30-43

(86-110)

30-63

(86-145)

Hot Northern Africa, Middle East, Pakistan and India, southwestern 

United States and northern Mexico.

32-49

(90-120)

33-71

(91-160)
Section 6 | 45

Portable Radio 

Selection 

and Use

Additional guidance can be found in the following 

NFPA standards:

NFPA 1561

6.3 Emergency Traffic. 

6.3.1* To enable responders to be notified of an 

emergency condition or situation when they are 

assigned to an area designated as immediately 

dangerous to life and health (IDLH), at least 

one responder on each crew or company 

shall be equipped with a portable radio and 

each responder on the crew or company shall 

be equipped with either a portable radio or 

another means of electronic communication.

NFPA 1221

9.3.6 Two-Way Portable Equipment.

9.3.6.1 All Emergency Response Units (ERUs) 

shall be equipped with a portable radio that is 

capable of two-way communication with the 

communications center.

9.3.6.2 Portable radios shall be manufactured 

for the environment in which they are to be 

used and shall be of a size and construction 

that allow their operation with the use of a 

gloved hand.

9.3.6.10 Spare batteries shall be maintained in 

quantities that allow continuous operation as 

determined by the authority having jurisdiction 

(AHJ).

9.3.6.11 A minimum of one spare radio shall be 

provided for each 10 units, or fraction thereof, 

in service.

What Type?

Since radios are tiered based on performance and 

ruggedness, there can be significant cost savings 

by buying high-tier radios for responders and the 

appropriate lower tiered radios for support staff 

(Figure 6.2).

High-tier: High-tier radios should be provided 

to each firefighter. This level of radio gives the 

highest level of performance and reliability that 

radio manufacturers can provide. Within each 

tier, there may be options that provide additional 

capabilities or functions. If using radios for EMS 

and fire functions, encryption may be required for 

operations with law enforcement agencies or to 

comply with the Health Insurance Portability and 

Accountability Act of 1996 (HIPAA) requirements.

Figure 6.2. Examples of Various Tiered Radios

High-Tier Mid-Tier Low-Tier

(Photos courtesy Motorola Solutions and Harris)
Voice Radio Communications Guide 46 for the Fire Service

Mid-tier: Mid-tier radios may be appropriate 

for users who do not enter into the firefighting 

environment. This type of radio would be a good 

choice for EMS functions. Again, encryption may 

be required to meet HIPAA requirements. 

Low-tier: Low-tier radios are an option for some 

support staff. These radios provide communications 

for users who are not in harsh environments and 

may not need all the functionality of the higher 

tier radios.

Multiband

Multiband radios are now offered and can 

provide added levels of interoperability or provide 

flexibility to improve operability. The selection of 

which multiband radio may require assistance from 

the spectrum coordinators in your department or 

area of operation. Depending on the manufacturer 

of the radio, the radios are commonly triband 

(VHF, UHF, 700/800 MHz) or dual band. In 

dual band radios, a decision on which two bands 

provide the best use in your jurisdiction will have 

to be decided. The access to multiple bands has 

the capability of providing interoperability with 

other jurisdictions or disciplines you interact with. 

Having access to multiple bands and channels does 

not create interoperability. Interoperability must be 

planned, coordinated, agreed upon, trained for and 

practiced to be effective when you need it.

Having access to multiple bands also can enhance 

operability. In the metropolitan area of Phoenix, 

Arizona, use of multiband allows the firefighters in 

the region to use a 700/ 800 MHz trunked radio 

system for dispatch and EMS-related calls. Fire 

calls are run on VHF analog direct channels. This 

model allows the participating fire departments to 

use the trunked system for interoperability with 

law enforcement, meet wide-area communications 

needs, and use VHF direct for operations with 

local command, such as at fire incidents. Having 

two systems has the added benefit of providing 

redundant systems for increased reliability. Just 

a few years ago, they had to operate on two 

different radios.

National Institute of Standards and 

Technology Testing

NIST has performed testing on portable radios that 

closely replicates the firefighting environment.

Technical Note 1477

Technical Note 147724 test results exposed the 

vulnerability of the portable radios to elevated 

temperature conditions and emphasized the need 

to protect the radios when used in firefighting 

situations. Radios tested inside the turnout gear 

pocket showed that the turnout gear pocket was 

able to protect the radios and allow them to operate 

at the Thermal Class III temperature of 260 C (500 

F). This contrasts with tests where the radios were 

exposed directly to the airflow, in which the radios 

did not survive at Thermal Class II conditions and 

beyond. In all but one test, the exposed radios 

were able to operate properly at the Thermal Class 

I temperature of 100 C (212 F), above the listed 

maximum operating temperature of 60 C (140 F). 

Failure of the electronics due to heating was not 

permanent for the radios. In all cases where the 

radio casing was not damaged, the radios regained 

normal operating function once they had cooled 

sufficiently. Permanent damage to the casing, such 

as difficulty turning knobs or pressing buttons, did 

occur for some radios whose casings experienced 

melting. Permanent damage also occurred to the 

external speaker/microphones, especially due to 

the melting of the connecting cables.

Technical Note 1850

Technical Note 185025 was released in September 

2014. The purpose of this study was to determine 

the firefighting environment that the radios operate 

in. While NFPA 1221 states: “Portable radios shall 

be manufactured for the environment in which 

they are to be used and shall be of a size and 

construction that allow their operation with the use 

of one hand,”26 no standard had been developed 

to quantify the firefighting environment. Seven 

radios were tested to measure radio performance at 

elevated temperatures. At 100 C (212 F), all radios 

maintained frequency. When the radios were 

24 Available at http://www.fire.nist.gov/bfrlpubs/NIST_TN_1477.pdf.

25 Available at http://nvlpubs.nist.gov/nistpubs/TechnicalNotes/NIST.TN.1850.pdf.

26 NFPA 1221-13, 9.3.6.2.
Section 6 | 47

Portable Radio 

Selection 

and Use

Figure 6.3. Various Types of Firefighting Equipment and National Fire Protection Association Temperature Rating

(Figure courtesy Mike Worrell)

subjected to 160 C (320 F) for 15 minutes, all of the 

radios experienced frequency drift, and some radios 

completely stopped transmitting. This is quite 

alarming and clearly indicates the need to protect 

the radios as noted in Technical Note 1477.

NFPA 1802, Standard on Personal Portable 

(Hand-Held) Two-Way Radio Communications 

Devices for Use by Emergency Services 

Personnel in the Hazard Zone

In response to a line of duty death in San 

Francisco, the San Francisco Fire Department 

asked the NFPA Standards Council to approve a 

new project to develop a standard for portable 

communications devices used in firefighting. 

The Council approved the project and assigned 

its development to the Technical Committee on 

Electronic Safety Equipment. Committee work on 

NFPA 180227 began in March 2013 to establish 

minimum requirements for the proper function 

of the communications equipment that operates in 

hostile thermal, IDLH, and nonhostile emergency 

scene environments. The goal is to increase the 

reliability of the communications equipment used 

by firefighters. The document, when issued, will 

not address interoperability, and its scope will be 

limited to the performance of the portable radio in 

the firefighting environment. 

Figure 6.3 is a comparison of equipment used in 

firefighting. It is easy to recognize that the NFPA 

temperature rating of the radio does not equal the 

same capabilities of other equipment in use by 

firefighters. The working group in cooperation with 

representatives from many fire departments, NIST, 

and the equipment manufacturers are working 

to define the operating environment and develop 

tests to create a standard for communications 

equipment. In addition to defining the environment 

and developing testing, the group is working 

to establish ergonomics standards so that the 

communications equipment is easier to use in 

the firefighting environment. In addition to 

defining the environmental requirements and test 

procedures, the working group is also identifying 

mandatory safety features of the radio. Most 

manufacturers have the features available, but the 

jurisdiction programming the radio must identify 

and program each feature and select the correct 

value for the firefighting environment. Often, the 

function or characteristic of each button varies 

depending on who is programming the radio. The 

NFPA 1802 Technical Committee is developing the 

standard set of safety features.

Fire Radio Features

Many features are available in modern radios. Like 

automobiles, stripped-down versions of radios are 

available. When options are added, the cost rises. 

To identify the desired features, focus and user 

groups can assist in developing the radio feature 

sets that meet users’ needs. Today’s radios are 

extremely flexible in programming features and 

the functions of buttons on the radio. Cooperation 

between the radio vendor and technical provider 

for your radio system will be instrumental 

in filtering through all of the programming 

parameters. Some of the newer features that 

increase firefighter safety are:

•	 Voice channel announcement: This feature uses 

voice prompts to notify the firefighter what 

channel the radio is on as the channel select 

knob is moved.

27 http://www.nfpa.org/codes-and-standards/document-information-pages?mode=code&code=1802.
Voice Radio Communications Guide 48 for the Fire Service

•	 Emergency indications: Radios on the 

fireground receive an indication of emergency 

activations on the assigned channel.

•	 Personnel accountability: There are more radio 

ID numbers available in new systems. This 

makes it possible for each radio to have an 

individual ID code enabling identification of 

the unit and specific position of the unit on 

an emergency activation. ID of the individual 

firefighter is possible if it is tied to roster 

information in a CAD system. 

•	 Tones: Many radios use tones as an indication 

of trunked system access, out of range, repeater 

access, encrypted channel, and other reasons. 

Use of tones may provide added awareness to 

the firefighter and increase safety. 

For guidance on the minimum feature set a radio 

should have, refer to NFPA 1221, Section 9.3.6.28

9.3.6 Two-Way Portable Equipment 

9.3.6.2 Portable radios shall be manufactured for 

the environment in which they are to be used 

and shall be of a size and construction that allow 

their operation with the use of one hand. 

9.3.6.3 Portable radios equipped with key pads 

that control radio functions shall have a means 

for the user to disable the key pad to prevent 

inadvertent use. 

9.3.6.4 All portable radios shall be equipped 

with a carrier control timer that disables 

the transmitter after a predetermined time 

that is determined by the authority having 

jurisdiction. 

9.3.6.5 Portable radios shall be capable of 

multiple-channel operation to enable onscene simplex radio communications that are 

independent of dispatch channels. 

9.3.6.6 Portable radios shall be designed to 

allow channels to be changed while emergency 

response personnel are wearing gloves. 

9.3.6.7 Single-unit battery chargers for portable 

radios shall be capable of fully charging the 

radio battery while the radio is in the receiving 

mode. 

9.3.6.8 Battery chargers for portable radios shall 

automatically revert to maintenance charge 

when the battery is fully charged. 

9.3.6.9 Battery chargers shall be capable 

of charging batteries in a manner that is 

independent of and external to the portable 

radio.

9.3.6.10 Spare batteries shall be maintained 

in quantities that allow continuous operation 

as determined by the authority having 

jurisdiction. 

9.3.6.11 A minimum of one spare portable 

radio shall be provided for each ten (10) units, 

or fraction thereof, in service.

9.3.6.12 Portable radios used by first responders 

who might encounter hazardous conditions 

likely to cause fire or explosion because of 

the release of flammable liquids or gases shall 

be rated as Intrinsically Safe by a recognized 

testing authority if determined necessary by the 

authority having jurisdiction.

Portable Radio User Training Guide

Firefighters often lack the basic knowledge and 

training of their portable radios, systems, and the 

capabilities of each. Training is required to form 

a basic operating knowledge and awareness of 

their radios. The awareness should include regular 

training and familiarization with the radio. The 

IAFF Fire Ground Survival (FGS) program states that 

“no probationary firefighter should enter the field 

without having practiced requesting resources and 

calling a Mayday. Furthermore, fire departments 

must have an ongoing training program specifically 

focused on using the radio” (IAFF FGS). Radios 

are often the only way to communicate on the 

fireground, especially in the case of an injured 

or downed firefighter. The next paragraphs will 

provide a simple and basic understanding of radio 

operations. It is not a prescriptive answer for every 

28 NFPA 1221-13.
Section 6 | 49

Portable Radio 

Selection 

and Use

situation nor will it go over every single type of 

radio. The goal is for users to understand how to 

care for their radio, how to wear their radio, radio 

discipline, and training.

When a firefighter arrives to the fire station or is 

checking his or her equipment prior to engaging 

in work, it usually involves placing his or her gear 

and equipment in a ready state. Depending on 

where you work or who you work for, the radio 

may not be a big part of this routine. If it is not a 

major part of the routine, then it should be. The 

radio provides the means to summon help for you 

or your fellow firefighter. A basic radio check-off 

would include proper inspection of the radio’s 

physical properties, such as knobs, switches and 

the antenna as well as the radio’s functionality. 

Users should also have some knowledge and 

understanding of battery/power supply life, 

rotation and maintenance. They should also be 

aware of the effect of temperature on the battery/

power supply. Further questions about radios can 

be answered in this report, your department’s 

technical personnel, or the manufacturer.

Users and their behaviors have an impact on the 

effectiveness of fireground communications. Human 

factors, such as the way we speak and organization 

of reports, affect communications. Technical 

factors obviously have an impact on fireground 

communications. Like any other technology, users 

need to know the limitations of the technology and 

how to use the tool appropriately.

Human Factors

When we talk on the radio, each of us 

subconsciously performs a process before we speak. 

Managing this process will provide more effective 

communications. Key aspects of managing this 

process include the following:

•	 Organization: Before speaking, formulate what 

information is being communicated, and put 

the information in a standardized reporting 

template. For instance, a standard situational 

report might contain Unit ID, location, 

conditions, actions and needs. This method 

forces users to fill in the blanks, answer all the 

necessary questions, and filter out unnecessary 

information.

•	 Discipline: ICs are often overwhelmed by 

excess information on the radio. Radio 

discipline on the fireground will help 

to determine if information needs to be 

transmitted on the radio. If face-to-face 

communications are possible between 

members of a crew and the information is not 

needed by the IC, don’t get on the radio.

•	 Microphone location: Placing a microphone 

too close to the mouth or exposing the 

microphone to other fireground noise may 

result in unintelligible communications. When 

transmitting in a high-noise environment, 

shield the microphone from the noise source. 

Hold the microphone a couple of inches from 

the mouth or, when speaking through an SCBA 

mask, place the microphone near the voice port 

on the facepiece.

•	 Voice level: Use a loud, clear and controlled 

voice when speaking into a microphone. 

When users are excited, their speech often is 

louder and faster. These transmissions often 

are unintelligible and require the IC to ask for 

a rebroadcast of the information, resulting in 

more radio traffic on the channel.

Managing these human factors will have a positive 

impact on fireground communications. Reporting 

should be complete, necessary, and in a controlled, 

clear voice. These actions will reduce the amount 

of repeat transmissions on the fireground and 

reduce air time. 

Technical Factors

In some cases, communications problems are 

caused by a technical issue. Users need to recognize 

technical problems and take corrective action 

to improve communications. Training users to 

understand the system they use, as well as features 

of the system such as VR and BDA, may help users 

to more readily recognize communications issues 

and take corrective action to rectify them. Radio 

users often blame the radio or system for coverage 

problems. In many cases, users’ actions can 

improve communications.
Voice Radio Communications Guide 50 for the Fire Service

Figure 6.4. Radio Placement

(Photos courtesy Cody Worrell)

Where to Wear Your Radio

Now that the radio is ready to be placed into 

service, the decision of where to wear the radio 

will have to be made (Figure 6.4). Most firefighters 

haven’t given much thought to where the radio 

should be worn. Not much thought has been given 

because the limitations are not fully understood. 

Many firefighters assume that the equipment they 

are given is bulletproof and tested to all of the 

same standards. The radios that the fire service uses 

are far from bulletproof, and where the radio is 

worn will have an effect on radio performance. In 

order to decide on where to wear the radio, radio 

accessories will also need to be looked at since they 

are a part of the ensemble.

Many users do not use a radio pocket or case. In 

the middle photo of Figure 6.4, the Company 

Officer’s (CO’s) radio (left) is clipped to the exterior 

of the coat, while the firefighter’s radio is protected. 

The trade-off is that the radio is exposed to heat 

and steam but is in a better transmitting position. 

When unprotected, the radio may fail to operate 

when needed. NIST tested seven different radios at 

a temperature of 320 F for 15 minutes; all radios 

experienced an issue. After testing concluded, 

three radios failed to recover, while the other four 

worked properly after cooling down. When a radio 

is in a pocket, the temperature reduction is 135 to 

167 degrees Fahrenheit cooler, which may keep the 

radio at the proper operating temperature, which 

was also tested by a NIST study. 

There have been many studies, blogs and articles 

written on the best practices for carrying your 

portable radio, the most prevalent being the coat 

pocket versus the radio strap underneath the coat 

with the speaker microphone protruding from the 

top of the firefighter’s coat. A number of factors 

play into the decision on where to carry, with pros 

and cons to both locations. The takeaway is to 

understand the limitations of what is issued to you 

and maximize the performance by your actions. 

No single location is optimal in all situations. A 

user that understands this limitation can react to 

a no transmit or no receive situation by changing 

something (i.e., body position or radio orientation).

Radios in the fire service vary greatly. Many were 

designed for public safety; however, manufacturers 

are now offering radios with “fire features.” The 

fire features include larger knobs but still can pose 

a challenge to manipulate with gloved hands. Take 

one look at the knobs and buttons on some fire 

service radios, and it will be obvious that they are 

not made for firefighters because they are difficult 

to use with gloved hands. The other agencies 

that use our same radios don’t find themselves 

transmitting with gloves on in environments that 

are hot and wet. All radios are susceptible to heat 

and moisture — to what degree, it may vary. 

Regardless, all firefighters should follow some basic 

rules on where to wear their radio. If firefighters 

are leaving the radio exposed, they are exposing 

themselves to danger and run the risk of making 

the radio inoperable. Protect the radio at all costs. 

Most turnout coats have radio pockets to protect 
Section 6 | 51

Portable Radio 

Selection 

and Use

the radio, but some may not. Many departments 

use radio harnesses as well to aid in protecting and 

carrying the radio (Figure 6.5).

Figure 6.5. Firefighter on the left with proper wearing of 

radio in pocket. Note minimal radio speaker microphone 

cord exposure. Firefighter on the right demonstrates use 

of the shoulder harness and leather case.

(Photos courtesy Cody Worrell)

An important factor in where the radio is worn 

depends on the antenna. Portable radio antennas 

are designed to work in an upright position, so 

the radio waves can transmit out. All firefighters 

reading this should have questions popping up 

in their minds. Firefighters often find themselves 

crawling on the floor on top of their radio. 

Being in this position limits the capabilities of 

the antenna; however, the user should be able to 

adjust and to help this. Depending on where the 

radio is will determine what may need to be done. 

If the radio is in the pocket, the firefighter may 

need to turn over to transmit. If the radio is worn 

around the waist, the firefighter may not need to 

do anything if the radio is exposed. The important 

thing to note is that the radio needs to be exposed 

so that it can transmit effectively. The other aspect 

to carrying a radio will be the accessories used in 

conjunction with it (Figure 6.6). 

Figure 6.6. Firefighter crawling in a poor transmitreceive position. In the second picture, the firefighter 

has adjusted position for better transmit. Note that the 

body is no longer shielding the antenna.

(Photos courtesy Cody Worrell)

Section 2, Recommendation 5 in the IAFC “Portable 

Radio Best Practices” states: “When practical 

consider the use of accessories, such as speaker 

microphones, throat microphones, and in-ear 

microphones, to reduce the impact of background 

noise” (IAFC Best Practices, p.18). Another factor 

is the use of remote speaker microphones (RSMs) 

and other accessories that allow the radio to 

be protected in a harness or pocket from heat. 

Radio pocket protection has been proven by 

NIST Technical Note 1477 where temperatures in 

the pocket were 135 to 167 degrees Fahrenheit 

cooler than outside the pocket29 (converted to F). 

Other common radio accessories found in the fire 

service are remote speaker mics, amplifiers and 

talk-around systems. RSMs connect to the radio 

with a pin connection and have a cord that attaches 

to the speaker and microphone (Figure 6.7). The 

RSM is also commonly referred to as a lapel mic. 

RSMs have been in use for a long time and are 

recommended as a best practice by the IAFC30

because they can dramatically reduce the impact 

of background noise on audio intelligibility. RSM 

problems were documented in the Houston Fire 

Department31 and San Francisco Fire Department32

line-of-duty deaths (LODDs) reports.

In San Francisco, an LODD report concluded that 

“victim 1’s remote speaker/microphone failed 

due to high heat/fire, causing constant transmit 

condition. This disabled the radio from transmitting 

29 NIST 1477, p. 6.

30 http://www.iafc.org/files/digProb_PortableRadioBestPractices.pdf, Section 2, p. 18.

31 Houston Fire Dept. Southwest Inn Recovery Committee Final Report and Recommendations Sept. 1, 2014.

32 San Francisco Fire Dept. Safety Investigation Report Line of Duty Deaths 133 Berkeley Way June 2, 2011 Box 8155 

Incident #11050532.
Voice Radio Communications Guide 52 for the Fire Service

or receiving after 60 seconds.” The biggest problem 

has been the cord that connects the speaker/

microphone to the radio body. The cord can melt 

causing a short. When the short occurs, the radios 

are sometimes keyed up, unbeknownst to the user, 

or inoperable. The user needs to protect the cord 

to help prevent this from happening. The cord can 

be tucked into the radio pocket or underneath the 

jacket where temperatures are significantly cooler. 

It is worth noting that some manufacturers offer 

cords that can withstand 500 F temperatures, as 

well as having more firefighter friendly features. 

These are just two solutions; there is no prescriptive 

answer. Furthermore, the IAFC recommends that 

special attention be paid when selecting radio 

accessories to ensure that they are compatible 

with the environment that they are to be used 

in.33 What the last sentence is saying is that not all 

cords are created equal, so the user must know 

the temperature ratings of his or her equipment 

because they may be different.

Figure 6.7. Remote Speaker Microphone Examples

(Photos courtesy Harris and Motorola Solutions)

Amplifiers are attached to the SCBA facepiece 

(Figure 6.8). The amplifiers do not connect to the 

radio; they only amplify the voice of the user out 

of the SCBA mask. A benefit of the amplifier is that 

users do not need to significantly raise their voice 

to be heard. Transmissions sound better and more 

controlled because the users are not required to 

yell. The amplifiers operate off batteries that need 

to be tested and maintained. The amplifiers are 

only effective if the user places the radio or RSM 

in the correct area when speaking. The user will 

position his or her radio 1 to 2 inches from the 

audio source when in use as recommended by the 

IAFC “Portable Radio Best Practices” report. Once 

again, it is important to note that the temperature 

rating of the equipment needs to be known. 

Figure 6.8. Example of a Self-Contained Breathing 

Apparatus Voice Amplifier

(Photo courtesy Scott Safety)

The third accessory is a talk-around system. Some 

SCBA manufacturers produce a talk-around system 

that attaches to the facepiece. The models may offer 

multiple talk-around channels that allow users to 

talk with each other on the fireground. A benefit 

of this system is that users can talk to each other 

without tying up airtime on the tactical channel. 

Airtime is available for important information and 

maydays. This type of system would aid in mayday 

situations because interior crews communicate 

without being on the tactical channel. The systems 

also can attach to the radio. There is a switch to 

allow you to talk through the radio. The talk-around 

system may have a PTT button on the facepiece 

itself. The RSM cord is the same that is used for this 

system as well. The dangers listed above in the RSM 

section apply to this piece of equipment as well.

The question of where to wear the radio depends 

on all of the factors discussed above. Proper 

placement should be where the radio transmits 

and receives reliably. There is no prescriptive 

answer for where the radio should be. The radio 

33 IAFC “Portable Radio Best Practices.”
Section 6 | 53

Portable Radio 

Selection 

and Use

should be protected and in a place where the user 

is comfortable operating it with his or her given 

equipment. Proper placement of the radio has 

been a researched topic by multiple agencies and 

departments. The research has shown that the radio 

needs to be protected, or it may malfunction.34,35

Placing the radio in a turnout coat pocket resulted 

in a temperature difference of 135 F to 167 F.

Coverage

When communicating on the fireground, some 

areas of a building may be difficult to communicate 

from. When encountering these areas, move to 

a location where communications are possible. 

Areas that may improve communications are near 

windows and doors.

Accessories

Many accessories are available for radios. Use of 

accessories that protect the radio from heat and 

steam allows the radio to operate in high-heat 

environments. Each user group may have specific 

working conditions that require some accessories 

to make radio communications easier. Common 

accessories include carrying cases, speaker 

microphones, ear pieces, chargers, battery types, 

and optional antennas. A few considerations when 

evaluating radio accessories are:

•	 Is the accessory approved for firefighter use in 

the IDLH environment?

•	 Does the accessory hinder the firefighter in 

donning PPE?

•	 Can buttons/controls be manipulated with PPE?

•	 Is there a method to disengage accessory in case 

of snare or malfunction?

User and focus groups will help identify the 

accessories needed to support your department’s 

needs.

Summary — Portable Radio Selection and Use

Portable radio equipment is what the firefighter 

sees and has the most impact on fireground 

communications. Firefighters expect the radio is 

going to work when the PTT is pressed. Multiple 

tiers of radios are available at different price points. 

Select the appropriate radio for entering the hazard 

zone. Today’s radios have better ergonomics than in 

the past, and firefighters should be able to operate 

them with a gloved hand.

Radios are currently manufactured to meet MILSTD 810. Environmental specifications for this 

standard range from minus 22 F to 140 F. This has 

proven to be a weakness.

NFPA 1561 and 1221 are guiding documents 

on the type and capabilities of the radio and 

should be referenced during radio purchases or 

system design.

NIST Technical Notes

1477: This study tested radios in the firefighting 

environment and proved that radios protected 

from the direct heat increased the survivability of 

the radios.

1850: This study tested seven radios and subjected 

the radios to 320 F for 15 minutes. All radios 

experienced frequency drift, and some completely 

stopped transmitting.

NFPA 1802

Draft development of this document began in 

March 2013 with the establishment of minimum 

requirements for the proper function of the 

communications equipment that operates in hostile 

thermal, IDLH, and nonhostile emergency scene 

environments. Turnouts, thermal imaging cameras 

(TICs) and PASS units are all rated for 500 F for five 

minutes. The radio is the only piece of equipment 

that does not meet the 500 F rating. The standard, 

when issued, will also mandate basic safety 

functions on the radio.

User Guide

As with any equipment used in the fire service, 

training is a key factor in successful use of the 

34 NIST TN 1850.

35 NIST TN 1477.
Voice Radio Communications Guide 54 for the Fire Service

equipment. This is especially true when in high 

stress situations. Users need to be aware of actions 

that they can take to successfully communicate:

•	 Organized thought process.

•	 Discipline — when to speak, what to speak, 

controlled voice (speed and amplitude).

•	 Equipment.

– Component location — microphones, voice 

ports, antennas.

– Position where the radio is worn — 

protected.

– No single location is optimal in all

situations. A user that understands this 

limitation can react to a no transmit or no 

receive situation by changing something 

(i.e. body position or radio orientation). 

– RSM use.

•	 Recognition of coverage (poor transmit or 

receive):

– Change radio or body position — get the 

antenna vertical.

– Move toward windows or exterior of the 

building and retransmit.
Section 7 | 55

System 

Design and 

Implementation

SECTION 7 — 

System Design and Implementation

Project Organization

Designing and implementing a communications 

system is an extremely complicated process. It is 

important to create a structured organization to 

provide input, carry out decision-making, and 

conduct implementation work on the project. Get 

the organization established before beginning 

the project.

Everyone affected by the fire communications 

system should have a hand in its selection. This 

doesn’t mean everyone participates at every step, 

but it does mean stakeholders must be consulted 

and their needs given serious consideration. If any 

constituency gets left out of the planning process, 

those needs may get overlooked, and the result 

could be a system that fails to meet the requirements 

and expectations of the entire community.

When creating the project organization, be careful 

to clearly define the roles various workgroups have 

in the organization. The term “user” often has 

different meanings to different people, so using a 

more descriptive term is best to avoid confusion. 

Some example roles include:

•	 Front-line firefighters and the teams that 

support them in the field.

•	 Dispatchers and others who provide support 

away from the scene.

•	 Operational supervisors.

•	 Department and other organizational business 

management.

•	 Union representatives.

•	 Elected officials.

•	 Personnel from other agencies that collaborate 

with the fire service.

Interoperability is a major concern in today’s 

world. The ability of public safety agencies to 

communicate with each other is critical when 

events require them to coordinate a joint response. 

Many localities are answering this need by 

designing large networks that will be shared by 

multiple departments and sometimes by multiple 

cities and counties.

If your community is working on a 

communication system that will be shared by 

other entities in addition to the fire service, you 

need to be collaborating with representatives of 

those organizations. You’ll face the challenge of 

giving each agency’s needs appropriate weight. The 

law enforcement component of the system may 

often drive the overall direction of the project, but 

it’s essential for the fire service to make system 

designers aware of the needs of the fire service 

and to make sure that the system is designed to 

accommodate those needs.

Each community has a different approach to 

organizing the planning effort. Typical efforts 

include:

•	 A steering committee with top leadership 

setting the overall policy agenda. Every attempt 

should be made to have fire department 

management and labor leadership as 

participants on the steering committee at the 

project’s earliest stages.

•	 Working groups that are assigned to complete 

specific tasks and report back to the steering 

committee. If you are appointed to one of 

these groups, it sometimes can be difficult to 

determine exactly what your role is supposed 

to be — both as a group and as individuals. It 

is important that fire department management 

and labor are involved in establishing the goals 

and expectations for each work group.

Requirements Definition

You may be collaborating with other departments to 

build a shared multiagency network, or you may go 

it alone on a system for the fire service only. Either 

way, the more you learn about your department’s 

needs, the more effectively you can represent the 

perspective of the fire service in your community.

The design and procurement of radio systems for 

fire departments is technical and very expensive. 

Many departments rely on expertise outside of the 

fire service to advise them on communications 

technologies. Often these technical experts do not 

have a complete understanding of the fire service 
Voice Radio Communications Guide 56 for the Fire Service

or special requirements related to fireground 

communications. As a result, many communications 

systems are built to design parameters based on 

incomplete or inaccurate information. 

The development of a Requirements Definition 

provides an opportunity to analyze communications 

needs based on operational practices and 

inherent risks associated with fire operations. The 

Requirements Definition also provides a measurable 

parameter set to evaluate the current radio system. 

Identify Operational Needs

The planning horizon for a new communications 

system can range from a few months to several 

years. Once installed, the system could have a life 

of 10 years or more. The following are some things 

that must be considered.

Operational needs should be grouped into three 

different categories based on the frequency of use:

1. Everyday incidents that all departments engage 

in, including structure fires, vehicle crashes, 

location of fire facilities, etc.

2. Mutual and automatic aid responses that occur 

less frequently but are still common.

3. Major incidents like disaster responses 

requiring long-duration coordination between 

local, state and federal agencies with heavy 

logistical support.

When considering the operational needs in these 

categories, it is important that the everyday incident 

operations are not compromised for the rare 

complex incident. 

Major disaster response communications can 

be accommodated by using regional or national 

resources to supplement the everyday system, just 

as regional or national resources supplement the 

response and recovery response. This does not 

mean that communications planning for large-scale 

incidents is not necessary, only that you may not 

need a system that accomplishes all possibilities, 

no matter how unlikely. A large and complex 

radio system will be more complex for users, be 

more costly upfront, and require more operation 

and maintenance cost than a system designed 

for routine incidents. Consider the needs of the 

community and the risks involved before putting 

together a plan for the ultimate system.

Plan for Change

Communications needs can change over time due 

to community changes, such as population growth, 

density changes, geographic expansion, alliances 

with other communities, and evolving issues in 

homeland security and all-hazards management. 

Any investment you make today should have the 

potential to grow tomorrow.

Organizational changes like budget constraints, 

staffing changes, departmental realignments, the 

creation of new work teams and task forces, greater 

collaboration with state and federal agencies can 

also affect communications needs. Will you be 

hiring more firefighters, opening or closing stations, 

or fielding specialized teams such as hazardous 

materials, weapons of mass destruction (WMD), 

wildland firefighting, technical rescue, or others? 

There are a number of other things to consider.

•	 Be prepared with statistics that reinforce your 

department’s importance to the community. 

This includes how many incidents you handle 

each year, how many citizens receive service 

each year, and how many lives are saved. These 

can be hard to quantify, but some research 

should produce numbers you can use.

•	 Be familiar with your department’s planning 

initiatives, and be prepared to talk about 

anticipated growth, addition of fire stations, 

potential incidents, and disaster scenarios to 

demonstrate the importance of fire service 

preparedness.

•	 Focus on results. It’s not a question of how 

many antenna towers you have; it’s whether 

firefighters can communicate to coordinate 

tasks and strategies or hear emergency traffic 

or a mayday call when they’re working inside a 

building. Emphasize how each decision affects 

the safety of your personnel and citizens.

With the current focus on interoperability, don’t 

lose sight of the basic mission. It is still more 

important to be able to respond effectively and 

safely to the everyday incidents than it is to provide 

for every possible (and unlikely) disaster scenario. 
Section 7 | 57

System 

Design and 

Implementation

This is not to say that interoperability is not 

important, but don’t sacrifice a system that you can 

use for a rarely used feature.

Evaluation of Current System

What is the current state of your fire 

communications? This is not an easy question to 

answer. It’s not uncommon for a department to use 

more than one communications system, and even 

with the same equipment, procedures can vary 

markedly. Collecting this information and pulling 

it all together in one place is a necessary step that 

requires the commitment of time and resources. 

An assessment of your current communications 

will help in identifying gaps in your 

communications infrastructure and plans, 

and identifying what it does well will assist in 

determining the need for a new system, or if 

updating the old system would be cost effective. 

Few departments keep statistics about radio usage 

and performance, so you’ll have to generate 

much of this information from scratch. Many 

departments use technical staff, vendors or bring 

in a consultant at this phase, especially to help 

with the more technical aspects of the job, such 

as charting call traffic and measuring grade 

of service. A consultant also can be helpful in 

collecting “softer” data. Soft data might include 

user perception of the current system or where 

users feel where improvements need to be made. 

Sometimes it’s easier for an outsider to interview 

users and get their honest feedback on how the 

system works or doesn’t work for them.

It may be beneficial to create scenario descriptions 

that describe all communications flows for various 

types of incidents from receipt of the call by the call 

taker, through dispatching units, unit response, and 

incident management and logistics support. Consider 

all aspects of the communications including the 

use of pagers and station alerting, mobile data, and 

wide-area and fireground voice communications. 

The most expensive communications system will be 

of little use if a major function performed today is 

left out of the future system.

Finally, consider the state of physical infrastructure, 

such as communications building condition and 

susceptibility to weather effects, tower condition, 

commercial and backup power sources, and 

communications backhaul (telephone lines, data 

circuits, and microwave systems).

Funding

After the needs are identified, the budget can be 

developed. If the budget is developed too early, the 

system design may be unduly constrained. When 

this happens, it is inevitable that functionality and 

performance will be lost. Once the budget is set, 

it will be very difficult to get additional funding 

later to “get it right,” especially if other agencies are 

pushing forward. 

One method for getting a rough budget in place is 

to survey similar agencies with similar needs on 

the cost of their system or hiring a consultant to 

make a system design recommendation and cost 

estimate based on your system needs. Another 

method is to issue a request for information (RFI) 

to manufacturers and system integrators describing 

your operational communications needs and 

requesting a rough not-to-exceed cost for a system. 

Regardless of the method used for the estimate, 

this type of information will be very rough since 

the system design will be based on incomplete 

information and limited detail. It is difficult to get a 

solid cost without going through a complete system 

design with a specific manufacturer’s equipment.

Alternative Funding Sources

Funding is a huge issue, but it should not be 

your first consideration when assessing your 

communications requirements. With the 

renewed focus on public safety and first-response 

capabilities, more funding is becoming available 

through federal, state and regional government 

grants. Examples include:

•	 State Homeland Security Grant Program (HSGP) 

and Urban Areas Security Initiative (UASI), 

administered by DHS through the Office for 

Domestic Preparedness (ODP)

(https://www.fema.gov/fy-2015-homelandsecurity-grant-program).

•	 Assistance to Firefighters Grant Program, 

administered by FEMA (https://www.fema.gov/

welcome-assistance-firefighters-grant-program).
Voice Radio Communications Guide 58 for the Fire Service

•	 USFA document “Funding Alternatives 

for Emergency Medical and Fire Services” 

(http://www.usfa.fema.gov/downloads/pdf/

publications/fa_331.pdf). 

In some cases, it may be feasible to participate in 

joint investments with other agencies or nearby 

communities. This will allow for networking 

facilities, such as core systems, repeater systems, 

fire-alerting systems, and towers. Costs can be 

shared among several different organizations. This 

also improves day-to-day interoperability among 

these organizations.

Explore leasing agreements and other financing 

alternatives as opposed to immediately committing 

upfront capital investment. Phased implementation 

plans and adaptable networks that start small and 

add more capabilities over time as the funding 

becomes available are also an option. Do not 

allow cost to become a barrier that prevents your 

community from building the fire communications 

system its citizens and your colleagues deserve.

Grant Writing

If you decide to try to obtain grant funding, it 

is important that you get started on the grant 

proposal early and spend the necessary time to 

get the proposal right. A successful grant proposal 

is well-prepared, thoughtfully planned, and 

concisely packaged. 

Become intimately familiar with the grant criteria 

and the eligibility requirements. You must be 

able and willing to meet these requirements. You 

might find that eligibility would require providing 

services otherwise unintended, such as working 

with particular client groups or involving specific 

institutions. You may need to modify your concept 

to fit. Talk to the grant information contact person 

to determine whether funding is still available, 

what the applicable deadlines are, and what process 

the agency will use for accepting applications.

Determine whether any similar proposals have 

already been considered in your locality or state. 

Check with legislators and area government agencies 

and related public and private agencies that currently 

may have grant awards or contracts to do similar 

work. If a similar program already exists, you may 

need to reconsider submitting the proposed project, 

particularly if duplication of effort may be perceived.

Enlist the support of community leaders. Once 

you have developed your proposal summary, look 

for individuals or groups representing academic, 

political, professional, and lay organizations that 

may be willing to support the proposal in writing. 

The type and caliber of community support is 

critical to your proposal’s ability to survive the 

initial and subsequent review phases.

You probably can develop the proposal without 

hiring a grant writer. Most fire grant programs 

are designed so that an astute member of any fire 

department can write a successful application. 

FEMA has a help desk staffed with competent 

professionals who help applicants through the 

process. In addition to the help desk, FEMA offers 

free grant-writing seminars and supports a website 

with helpful grant information (https://www.fema.

gov/welcome-assistance-firefighters-grant-program).

Evaluation of Proposed Technologies

After collecting the description of the current 

communications system, armed with a 

Requirements Definition and rough budget, a 

comprehensive evaluation of your current system 

and proposed technologies can be made. The 

Requirements Definition becomes the scorecard 

where the current and proposed technologies can 

be graded on compliance, partial compliance, 

or noncompliance. All components of the 

Requirements Definition may not be compliant 

in all technologies. Each department will have 

to evaluate each component of the Requirements 

Definition and derive an importance factor to 

determine if noncompliance or partial compliance 

is acceptable for its department.

Technical Options and Conceptual Design

What technology is available to close the gaps 

between operational needs, federal, state and local 

mandates, and the current system? Select the best 

combination of technologies that close the gaps 

without compromising the mission. Keep in mind 

the safety of firefighters, mission effectiveness, and 

long-term sustainability when making decisions.

New technologies: While you can’t predict every 

future capability, you can read news reports and 

technology journals for emerging systems, pilot 

programs, and development projects. Look for 
Section 7 | 59 System 

Design and 

Implementation

military spinoffs that will be adapted to the fire 

service. This is how we got TICs for locating 

fire victims and missing personnel, GPS location 

systems, and radios that can operate using different 

frequency bands and protocols as needed. Radio 

networks will be able to support a range of new 

features in the coming years. Even if you don’t have 

the funding to activate these features today, you may 

choose to invest in a system that will be capable of 

supporting them later. These may include:

•	 Voice-activated intercom systems that would 

allow multiple interior attack firefighters to 

communicate while keeping their hands free.

•	 Large, accessible buttons on turnout gear to 

enable immediate distress signaling.

•	 Radio-linked PASS devices that alert a Safety 

Officer if a firefighter remains motionless for 

too long.

•	 Encryption to maintain operational security 

when needed.

As an advocate for the fire service, you can use 

these tips to help ensure that your concerns will 

not be lost in the shuffle. While many of these 

technological improvements will prove to be 

beneficial to firefighters in the future, this guide is 

directed primarily at voice communications.

Should You Hire a Consultant or System 

Integrator?

Consultants can provide technical knowledge about 

systems — and should have up-to-date knowledge 

of what various manufacturers can provide to 

meet differing communications needs — and 

can provide design and procurement assistance, 

as well as implementation project management. 

Manufacturer-neutral system integrators can 

provide equipment and labor to design and 

implement a complete system and will typically be 

responsible for providing the final working system. 

Time, staffing and know-how are factors in deciding 

whether to hire a consultant or integrator. Do you 

have people with the necessary technical capabilities 

and an understanding of complex modern 

communications systems? Does your organization 

have time to do the job alone? Can you obtain the 

necessary staff internally? Do your people know 

how to perform the assigned tasks? If the answer is 

“no” to any of these questions, consider getting the 

assistance of a consultant or integrator.

Even if you have some degree of technical capability 

in-house, use of an outside contractor brings 

the benefit of experience. The contractor has (or 

should have) more experience than you in dealing 

with communications challenges and providing 

communications project oversight. Contractors 

also provide an outsider’s viewpoint, which can be 

valuable when there are conflicting requirements. 

Contractors can be hired to perform a single, clearly 

defined task or to take on a more comprehensive 

role in the project implementation. Often, it’s wise 

to hire a consultant for a small-scale project and see 

how he or she performs before turning over largescale responsibility for a major project.

If you decide to use a contractor, ask these 

questions before you hire:

•	 Have you worked with other public safety 

agencies before?

•	 Have you worked with fire departments before? 

Discuss some typical issues in fire department 

operational communications to see how 

familiar the contractor is with the issues and 

risks to the fire service.

•	 Have you worked with fire departments of 

our size?

•	 Are you able to provide assistance to overcome 

budget issues, such as grant writing, 

understanding the bond process, and creative 

financing solutions?

•	 What types of systems have resulted from 

your work?

•	 What are some of your successes, what were 

some of your failures, and how did you 

overcome them?

•	 Who are your references, and how can we 

contact them? 

•	 Investigate relationships between the 

contractors and vendors.
Voice Radio Communications Guide 60 for the Fire Service

Where to Get Advice

Whether or not you use a contractor, investigate 

these alternative sources of assistance and 

information:

•	 Other communities: Chances are that another 

agency similar to you has been through this 

process already. Look at other departments 

of comparable size, contact their committee 

members, and arrange a meeting or conference 

call where you can “pick their brains.”

•	 Conferences: Attend fire and public safety 

conferences with an eye for communications 

sources. Programs, panels, vendor displays, 

demo projects ... they’re all good places to get 

information and hook up with others who have 

experience they’re willing to share.

•	 Vendors: Manufacturers and system integrators 

often can provide brochures, white papers, and 

similar information resources. This is another 

place to find information about technical issues. 

An established vendor understands that wellinformed customers are the best customers and 

that providing accurate information is one way 

to build a strong, lasting relationship and ensure 

the customer’s long-term satisfaction. Be cautious 

of vendors who are in business solely to make 

money, not necessarily to meet your needs. 

Currently, there is a lack of real competition due 

to the extremely small number of companies 

who build these systems. You must have a strong 

labor/management commitment not to use 

a system until it is proven to be safe and cost 

effective and to get the best system performance 

from the contractor.

•	 Government and professional organizations: 

Several national organizations act as 

clearinghouses for information about public 

safety communications. Again, a word of 

caution: While the organizations listed below 

do good work in the areas of interoperability 

and system standardization, no other 

organization outside of the IAFF is focused on 

the special needs of firefighters involved in 

interior operations.

– DHS SAFECOM program: The SAFECOM 

program’s mission is to help local, tribal, 

state and federal public safety agencies 

improve response through more effective 

and efficient interoperable communications 

(http://www.dhs.gov/safecom).

– DHS Science and Technology Directorate, 

Office for Interoperability and Compatibility 

Office of Emergency Communications: This 

is an operating unit within DHS Science and 

Technology’s First Responders Group (FRG), 

which provides the science and technology 

that enables emergency communications 

and facilitates the seamless exchange of 

information to protect property and save 

lives (http://www.dhs.gov/st-oic).

– SAFECOM provides guidance, tools, and 

templates on communications-related

issues and supports research and testing of 

communications products for public safety 

(http://www.dhs.gov/safecom).

– APCO is a professional organization whose 

mission “... provides leadership; influences 

public safety communications decisions 

of government and industry; promotes 

professional development; and, fosters the 

development of technology for the benefit 

of the public.” APCO sponsors the P25 

digital radio standards process. APCO’s focus 

is primarily on technical and operational 

standards relating to communications 

systems and communications centers 

(https://www.apcointl.org).

– The National Public Safety 

Telecommunications Council (NPSTC) 

is a federation of federal, state, and local 

associations and agencies. It serves as a 

liaison among the FCC, Congress and 

appointed officials involved in public safety 

communications. NPSTC was originally 

formed to implement the recommendations 

of the Public Safety Wireless Advisory 

Committee (PSWAC). NPSTC has taken on a 

wide range of activities related to spectrum 

policy coordination and the development of 

new technologies (www.npstc.org). 
Section 7 | 61 System 

Design and 

Implementation

– NFPA: The mission of the international 

nonprofit NFPA, established in 1896, is to 

reduce the worldwide burden of fire and 

other hazards on the quality of life by 

providing and advocating consensus codes 

and standards, research, training, and 

education. The world’s leading advocate of 

fire prevention and an authoritative source 

on public safety, NFPA develops, publishes, 

and disseminates more than 300 consensus 

codes and standards intended to minimize 

the possibility and effects of fire and other 

risks (http://www.nfpa.org/).

– IAFF is the driving force behind nearly 

every advance in the fire and emergency 

services in the 21st century. With 

headquarters in the District of Columbia 

and Ottawa, Ontario, the IAFF represents 

more than 300,000 full-time professional 

firefighters and paramedics in more than 

3,100 affiliates. IAFF members protect 

more than 85 percent of the population 

in communities throughout the U.S. and 

Canada (http://www.iaff.org/).

– IAFC represents the leadership of 

firefighters and emergency responders 

worldwide. Their members are the world’s 

leading experts in firefighting, EMS, 

terrorism response, hazardous materials 

spills, natural disasters, search and rescue, 

and public safety policy. Since 1873, the 

IAFC has provided a forum for fire and 

emergency service leaders to exchange 

ideas, develop professionally, and uncover 

the latest products and services available to 

first responders (http://www.iafc.org/).

– TIA is the leading trade association 

representing the global information and 

communications technology (ICT) industry 

through standards development, policy 

initiatives, business opportunities, market 

intelligence and networking events. With 

support from hundreds of members, 

TIA enhances the business environment 

for companies involved in telecom, 

broadband, mobile wireless, information 

technology, networks, cable, satellite, 

unified communications, emergency 

communications and the greening of 

technology. TIA is accredited by American 

National Standards Institute (ANSI) (http://

www.tiaonline.org/).

– National Interagency Fire Center (NIFC): 

The U.S. Department of Agriculture (USDA) 

and the Department of the Interior provide 

information on the use of radios in fighting 

wildland fires. Much of this information 

also applies to communications on 

structural fires. The information includes 

portable and mobile radio testing results, 

including digital radios, and training on 

various topics (https://www.nifc.gov/

NIICD/index.html).

Procurement

Based on the identified funding and the conceptual 

design, the next step is to solicit companies to 

construct the system. The procurement process 

typically will involve the development of a request 

for proposals (RFPs). The purchasing itself can 

often be assisted by using existing procurement 

agreements, such as state contracts or cooperative 

purchasing contracts. Be cautious, however, as 

these purchasing agreements are typically targeted 

at commodity purchasing and often do not take 

into account the complexities in purchasing widearea communications systems. This can make a 

seemingly simple purchase much more costly as 

items are purchased “a la carte.” System integration 

costs may dramatically increase the overall system 

cost. Also, a complex system procurement can 

include services such as system engineering services, 

communications building and tower construction, 

microwave system design and installation, and 

project management services that cannot be 

purchased as simple line items from a price sheet.

Developing the Request for Proposals

The more information about your community, 

your department, and your needs that you write 

into an RFP, the better. Vendors need to know 

about your operational needs and your current 

systems, so they can propose appropriate solutions. 

If it’s not in the RFP, you can’t expect to have 

it addressed properly in the proposals. Use the 

labor/management process to document user 
Voice Radio Communications Guide 62 for the Fire Service

requirements for operations as the foundation for 

all of the designs and studies that will follow. This 

is not about technologists and engineers telling 

you what technology you need. This is about you 

telling local government leaders and vendors what 

you need to support operations in the field.

It is very important to involve the agency’s 

purchasing personnel early in the purchasing 

process. This helps ensure that all state and local 

purchasing requirements are followed and that 

important contract language is included in the RFP. 

The RFP should include a summary of all of the 

steps taken to get to the RFP stage, including the 

results of the requirements gathering and current 

system analysis. The more background information 

you can provide to potential bidders, the closer 

their proposals will match your needs. In addition, 

by removing uncertainty from the purchasing 

process, you reduce the bidder’s risk, hopefully 

reducing the overall price.

The RFP development stage is a good time to have a 

consultant involved in reviewing the requirements 

and possibly assisting in the preparation of the 

RFP itself. Much of the RFP can be tedious to 

develop, and selecting a consultant who has done 

this work before will reduce the burden on the 

agency members. 

Evaluating Request for Proposals Responses

Modern radio networks employ many different 

technologies. The best choice for your community 

usually boils down to striking the right balance 

between initial cost and long-term capabilities. You 

need a system that fits your needs and available 

resources today, with the potential to grow and add 

more capabilities tomorrow.

Vendors’ responses to your RFP not only should 

detail the type of system they’re proposing but also 

explain why they’re recommending it over the 

alternatives. Vendors should be ready to answer any 

questions you have about the reasoning behind the 

recommended system design. Be sure vendors are 

recommending this design because it best meets 

your specific requirements. 

Some questions to ask about the proposed system 

and equipment:

•	 Does the system cover your routine and 

automatic/mutual-aid service area? 

•	 What is the vendor’s solution for fireground 

communications where the network doesn’t 

provide 100 percent coverage? What will 

users do if they are outside the range of your 

network system or indoors where signals don’t 

penetrate?

•	 Does the system have enough capacity to 

handle routine and abnormal incidents? What 

happens if the system becomes overloaded?

•	 How do other public safety and nonpublic 

safety users affect the fire department’s use of 

the system?

•	 How will the system facilitate interoperability 

with communications systems used by the 

departments with whom you have mutual-aid 

agreements?

•	 How will it alert units of dispatches in fire 

stations and when out of the station? Can the 

system accommodate any paging needs?

•	 Fire-capable end-user equipment (submersible, 

etc.) is more costly than the radios commonly 

recommended for police departments; be sure 

the quote includes equipment for the usage 

environment.

•	 Are the accessories you need included 

with each radio (battery charger, speaker 

microphones, etc.)?

Also, look for an understanding that deploying a 

new network is not just a technical challenge but 

also a major organizational change that requires a 

full support structure. 

The vendor’s response should include:

•	 Clear identification of how the technology will 

support your operations and not affect them 

negatively. Radio systems should be designed 

and implemented to support your work, not vice 

versa. Your existing internal procedures should 

not be affected negatively by the new system.
Section 7 | 63 System 

Design and 

Implementation

•	 A phased rollout plan for gradual transition 

from your current system to the new one.

•	 An upgrade/migration plan for making further 

changes in the future.

•	 User training information before, during 

and after implementation. This is far more 

important than most people realize. 

•	 System testing and acceptance procedures.

•	 Scenario-based training.

•	 Life cycle maintenance, network performance 

monitoring, and repair procedures.

•	 Software upgrades for radios and the system 

infrastructure. To evaluate the solution 

proposed by each vendor, you’ll need to 

understand the relative advantages of the 

technological choices each are recommending. 

The next chapter will help.

Implementation

Involve the right people throughout the 

implementation process. Thoroughly test the 

system as it is built to ensure that it is meeting 

needs and expectations.

Successful implementation/integration requires 

careful attention from the beginning to design 

compatible links and then test, test and test again. 

The vendor’s engineers must have a detailed plan 

that identifies all of the systems to be integrated 

and defines which capabilities will be made to 

work together and when. The plan also should 

include schedules and priorities and whether the 

new network will be made operational before all of 

the integration is completed.

Encourage everyone to ask questions and make 

comments. You will want to handle concerns and 

objections early, before they have the chance to 

evolve into rumors and long-standing gripes.

Before the contract is signed, ask the vendor 

or consultant to explain the following and 

begin to share that information with the rest of 

your department:

•	 What operational differences will our users 

notice between our current system and the 

new one? How will their procedures change? 

What new features will be available? Which, 

if any, of the old features will change or 

become unavailable?

•	 What’s different for the dispatchers? For field 

supervisors? For personnel back at the station? 

For personnel using the in-vehicle radios? For 

administrators and network managers?

•	 Will users still be able to use their old 

equipment, or will they be required to learn 

new equipment?

•	 What successes and pitfalls have been 

experienced by other fire departments 

implementing this type of system? What have 

you learned from previous deployments?

Training and Transition

Ensure that all firefighters and command staff 

members train with the system often prior to final 

switch over. Inadequate training is an especially 

critical problem and could endanger the lives of 

firefighters and the citizens they protect.

Training is far more than simply knowing how 

to turn on the radio and which buttons to press. 

Training must not become a one-time experience. 

Firefighters need initial exposure, formal training, 

and opportunities to incorporate radio usage 

into other training and simulation exercises. The 

integration plan also may cover interoperability 

with systems in other departments or jurisdictions. 

Interoperable communications must be tested with 

the joint cooperation of these other agencies and, 

perhaps, their system vendors as well. Training can 

be broken down into phases, as described below, 

that lead from general information on the system 

to specific operational aspects of the system, and 

finally to periodic refresher training.

•	 Awareness: This phase provides general 

information. A series of videos, using a live 

representative, explains what’s different about 

the new system and expectations for the new 

equipment. The goal is to create interest, not 

to provide detailed information, and hopefully 

begin to create champions within your system.
Voice Radio Communications Guide 64 for the Fire Service

•	 Education: Additional videos are distributed to 

provide more detailed information on topics 

such as how to use your radio and what the 

direct operational implications are of the new 

system or subscriber equipment. The videos 

may be broadcast over the department’s video 

network or local cable public safety access 

channel and also can be available in the station 

for firefighters to view at will. Lesson plans 

should be available on the department’s website. 

•	 Training: Six months to one year before the 

system’s operational deployment, use of the new 

radios is integrated into fireground training 

scenarios and in-building tactical preplan 

surveys. Training is structured in a three-month 

cycle. The first month, trainees focus on how 

to use the radio. In the second month, there’s 

a walk-through. In the third month, the radios 

are part of a live drill, complete with smoke, 

while trainees wear full turnouts. After this 

three-month cycle is completed, a new lesson 

plan is used in the next quarter, and the cycle 

continues until the entire set of training classes 

has been completed. 

•	 Transition: By the time the network is 

operational and transition begins, users will have 

had six months to one year of hands-on training. 

Two-thirds of the total training time is handson. Mobile radio training takes place at the time 

of installation of the equipment in the truck.

•	 Refreshers: Quarterly refresher training (with 

an emphasis on lessons learned) and just-intime updates should continue to be given, 

as well as an annual refresher on fireground 

communications. 

Beyond this training program, which was designed 

to support the rollout of the new radios, there 

are implications for other training organizations 

and curricula. 

Communications training must be integrated 

into all phases of recruit training and company 

training programs:

•	 Recruit training should incorporate radios from 

the beginning. In the past, radios were not used 

during recruit training, and a rookie’s first day 

on the job was the first day he or she was given 

a radio.

•	 The engineer’s academy, captain’s academy, 

and command officer’s academy, as well as 

special team training, should integrate radio 

communication throughout the curriculum.

Implementation Lessons Learned and 

Feedback

During the first few months after the initial cutover 

to a new system, collect and analyze information 

regularly on the operation of the system. Share 

this information among all members of the 

implementation team and, if issues are found that 

affect operations, share that with the field users. 

All members must be involved in providing 

feedback on system issues and must be kept 

involved with the solutions. Get buy-in from 

the system operator and technical staff to take 

field user input seriously. Encourage all members 

to report perceived deficiencies in the system, 

and follow up with the users with updates on 

their reports. If it appears to the users that their 

feedback is not acted on, they will stop providing 

that feedback. It is important to ensure that 

management is honest with users about the 

operation and safety of the system. If something 

isn’t working properly, disclose it, and find a workaround until the solution is found and in place.

Long-Term Operation and Maintenance

Ensure that adequate funding is allocated to the 

operation and maintenance of the system. Just like 

fire apparatus, the system must be maintained, and 

equipment must be replaced as it becomes unable 

to serve the agency’s needs. Continuously solicit 

feedback to keep on top of any problems that come 

up with the system over time. Throughout the life 

of the new network, fire service representatives 

will need a way to handle such ongoing 

responsibilities as:

•	 Answering users’ questions and helping them 

solve problems.

•	 Operating and maintaining modern radio 

systems is expensive. Long-term planning is 

required to maintain software and hardware 

that is required to keep systems operating at

peak levels. This is especially true of trunked 

radio systems that require frequent software 

updates/upgrades, and these eventually lead 
Section 7 | 65 System 

Design and 

Implementation

to required hardware changes. If a decision is 

made to fall behind and not maintain current 

software or hardware, the system is at risk of 

becoming nonsupported.

•	 Incorporating radio usage into new training 

programs and exercises, and presenting 

refresher courses.

•	 Monitoring the performance of the system 

and collecting reports of problems, such as 

buildings that lack coverage or situations in 

which there were not enough channels or 

talkgroups available.

•	 Implementing network interoperability links 

to support new mutual-aid agreements with 

other communities.

Summary — System Design and 

Implementation

Developing and implementing a new 

communications system can be a complex and 

expensive project. In the case of a large system, 

it may be the most expensive and most complex 

project a department has ever undertaken. These 

facts make it critical that the project is managed 

adequately.

•	 Establish a project team that includes 

fire department management and labor 

representation early in the project lifetime. 

•	 Involve all stakeholders and ensure that they 

continue to participate in the implementation 

process. 

•	 Gather information on the communications 

needs of field personnel and compare this to 

the radio systems they use. This comparison 

will result in a gap analysis that shows the 

deficiencies in the current system. The current 

system description along with the gap analysis 

can be used to produce a specification for the 

new radio system.

After the specification is established, a budget 

can be developed using the requirements and 

cost estimates developed from similar systems or 

through talks with potential vendors. Be cautious 

in reducing the system functionality if the cost is 

determined to be too large. Removing coverage or 

features from the system to reduce cost could affect 

the usability or safety of the entire system.

Once the implementation of the system has begun, 

familiarization and training should start as well. 

Early, simple training will provide end users with 

information on the system in a more controlled 

manner. If users don’t get the information they are 

seeking, they will find it through another path or 

will develop their own.

After the new system has been placed into 

operation, it is critical to follow up with end users 

on the operation of the system. Over time, users 

will find design, implementation and performance 

issues with the system that were not discovered 

prior to cutover, or that occurred after cutover. 

Timely resolution of these issues will ensure that 

your successful project remains successful in the 

eyes of its users.
Voice Radio Communications Guide 66 for the Fire Service

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Section 8 |Interoperability 67

SECTION 8 — 

Interoperability

This definition of interoperability is taken from the 

DHS SAFECOM project: 

“The ability of Public Safety responders 

to share information via voice and data 

communications systems on demand, in 

real time, when needed, and as authorized.”

In general, interoperability refers to the ability of 

emergency responders to work seamlessly with 

other disciplines, jurisdictions, systems or products 

without any special effort. Wireless communications 

interoperability specifically refers to the ability of 

emergency response officials “to share information 

via voice and data signals on demand, in real time, 

when needed, and as authorized” (DHS SAFECOM).

Frequency Coordination

Identifying interoperability frequencies often 

required research by frequency coordinating 

bodies or individual frequency coordinators from 

a jurisdiction. This task was often too difficult 

for a single fire department to tackle. The DHS 

published the National Interoperability Field 

Operations Guide36 (NIFOG) in 2007. This guide 

is a comprehensive listing of interoperability 

frequencies in all frequency bands and identifies 

both federal and nonfederal frequency listings. 

It is a common practice and advisable to include 

these frequencies in standard radio programming 

templates. This allows interoperability between 

disciplines, jurisdictions, and multiple levels of 

government — federal, state, county and local.

Interoperability Continuum

DHS, in collaboration with public safety agencies, 

developed the Interoperability Continuum to 

provide a roadmap to achieve interoperability 

(Figure 8.1). The continuum is a visual 

depiction of the multidimensional elements of 

interoperability.

Figure 8.1. Interoperability Continuum

36 http://www.dhs.gov/national-interoperability-field-operations-guide.
Voice Radio Communications Guide 68 for the Fire Service

Each lane in the continuum represents one element 

needed to attain some level of interoperability. 

Ideally, the right side of the chart is the highest 

level of interoperability. When looking at the 

chart, an organization may have some elements 

of the continuum on the right with others in the 

middle or to the left. While ideally the goal is to 

have all elements on the right side, the reality is the 

capability in each lane may vary, but the goal is to 

deliver interoperability as defined by the Office of 

Emergency Communications (OEC)/SAFECOM. 

An example of this would be use of “shared 

channels” for a planned event, elements of each 

lane provides a component of the interoperability.

•	 Governance — regional committee working 

within a statewide communications 

interoperability framework. The state has a plan 

for use of shared channels. This could be use of 

nationally recognized interoperability channels 

in the NIFOG.

•	 Standard operating procedures (SOPs) — 

agencies have joint SOPs for planned events to 

use the interoperability frequencies.

•	 Technology — shared channels from the NIFOG.

•	 Training and exercises — multiagency tabletop 

prior to a planned event.

•	 Planned event.

Day to Day

Most interoperability efforts are driven by the 

need to meet day-to-day operational requirements 

(Figure 8.2). In many large urban areas, the 

responsible fire department may not require dayto-day interoperability, while some departments 

interoperate on a daily basis. Since Sept. 11, 

2001, there has been significant attention toward 

efforts to expand interoperability past the dayto-day needs of a public safety agency to address 

extraordinary events and incidents. Interoperability 

is required and necessary in today’s world. Where 

and how it happens is based on a logical analysis of 

operational practices and requirements.

Figure 8.2. Response to a Motor Vehicle Crash

Motor Vehicle

Accident

Police Dispatch Fire/EMS Dispatch

Data, Phone or Radio

Communications

1. Fire & Law Enforcement 

 dispatched from their 

 Dispatch Center.

2. Each on separate radio 

 system.

3. Interoperability achieved by

 dispatch center cooperation.

4. On-scene interoperability

 achieved by face to face 

 communications

Law Enforcement

LE Channel 7

Traffic Investigation

Traffic Control

Fire/EMS

VHF Fire Channel

3

Fire

Triage/Treatment

Ambulance

Transportation

(Figure courtesy Mike Wieder and Ron Jeffers, Union City, New Jersey)
Section 8 |Interoperability 69

Many fire departments have interoperability with 

other fire departments. Interoperability between 

agencies in the same discipline is intradiscipline 

interoperability. Interdiscipline interoperability 

is between different disciplines. Intradiscipline 

interoperability is the easiest to achieve, since 

there is a common language, terminology and 

tactical objectives. Interdiscipline interoperability 

may not share common terminology or have the 

same tactical objectives. These factors should be 

considered in determining where interoperability 

occurs in the command structure. A prime example 

is when law enforcement responds to a house fire 

for traffic control. Each discipline has very different 

tactical objectives. As the fire responders fight 

the fire using the “common language” of the fire 

service, this terminology may not be understood 

by the law enforcement component. In addition, 

understanding when to talk and when not to 

talk becomes a safety issue. In these situations, 

interoperability may be face-to-face coordination 

with the command element or coordination at the 

dispatch center level. In the example below, both 

disciplines respond to a motor vehicle crash — 

fire/EMS for medical care and law enforcement for 

traffic investigation and traffic control.

The respective dispatch centers send the appropriate 

response for each discipline on separate radio 

channels and maybe even on different systems. 

Each responds, and when on-scene, they coordinate 

at the task level face to face. If a shared dispatch 

center and radio system were used, both units 

could be assigned on a common channel. SAFECOM 

would consider this a high level of interoperability. 

Large Incidents 

As incidents grow, interoperability should be 

planned for in the Command structure. When 

developing interoperable Command structures, 

many interoperability tools may be employed. 

Technical staff plays a pivotal role in providing 

these technology tools to meet the operational 

requirements. The technical staff must be familiar 

with the operational objectives and Command 

structure to supply the appropriate technological 

tools. NFPA 1221 recommends the use of a 

Communications Officer at all major incidents and 

a Communications Unit Leader (COML) is part of 

the National Incident Management System Incident 

Command System (NIMS-ICS) Command structure. 

The technical staff should receive the appropriate 

training to fulfill these roles successfully. COMLs in 

the NIMS-ICS Command structure provide a central 

point of contact to develop a communications 

plan to meet the interoperability needs on a large 

incident and manage the Communications Unit to 

meet the communications needs on an incident.

Communications Unit

The use of a Communications Unit has proven 

to improve interoperability on incidents. The 

individuals that fill these roles understand the 

technology and have a good understanding of 

operational requirements. The Communications 

Unit is tasked with supporting all communications 

needs on the incident. These requirements may be 

to provide operability in difficult situations where 

there are limited communications resources or in 

some instances no communications infrastructure. 

The Communications Unit consists of:

•	 COML: This position is tasked with the 

management of communications on the 

incident. Responsibilities include:

– Operational communications.

– Interoperability.

– Allocation of communication resources.

– Developing prioritization of the 

communications unit.

– Management of the communications unit.

– Knowledge of local interoperability plans, 

area and systems is helpful.

•	 Communications Technician (COMT): This 

position is the technical person assigned to 

implement technologies as directed by the 

COML. Knowledge of the following is necessary:

– Radio systems.

– Gateways.

– Portable radios.

– Telephone.

– Data systems.

– Knowledge of local area, systems is helpful.

•	 Incident Communications Manager (INCM): 

This position manages Radio Operators 

(RADOs) and communications center functions 

on incident if required.
Voice Radio Communications Guide 70 for the Fire Service

– Management of the communications center.

- Staffing of RADOs to cover operation 

periods.

- Monitoring of radio channels as 

required by the IC or Operations Chief.

- Recording and routing of messages.

•	 RADO: This position is responsible for 

communicating on assigned radio channels.

– Documenting notable events or radio traffic.

Jurisdictions need to understand the capabilities 

and resources the Communications Unit provides 

and develop a deployment plan for incidents or 

events where a COML would provide benefit. It 

is important to note that day to day our dispatch 

centers provide this function. The centers allocate 

and coordinate frequencies/talkgroups and 

provide communications resources as needed by 

operations. The Communications Unit’s role is 

to allow the dispatch centers to maintain normal 

operations. A Communications Unit may be 

implemented on large incidents that last many 

operational periods or special events that require 

complicated interoperability plans. A good example 

of this might be the Super Bowl, the presidential 

Inauguration Day, or other large special events. It is 

not always necessary to deploy a Communications 

Unit. Some events may only require a COML to 

develop the radio plan. The important takeaway 

is knowing where this capability is in your area. 

The state and federal governments have spent a 

substantial amount of money to train personnel 

as COML or COMT. Most states have a Statewide 

Interoperability Coordinator (SWIC). The SWIC in 

your state can assist you in identifying the COML 

or COMT personnel in your state. 

The example below is a large Command structure 

where multiple technologies are employed to 

achieve the appropriate level of interoperability for 

the incident (Figure 8.3). When interoperating, 

determining the number of channels needed to 

support the incident must be a consideration. It 

is always important to account for the amount 

of radio traffic on a channel and to reserve some 

airtime for unforeseen needs such as a mayday. 

Complex operations that are communications 

intensive should have their own channel to ensure 

that there is adequate on-air time and reserve 

Figure 8.3. Incident Communications

Shared System

Swapped Radio 

Inter Op Channel 

Shared Channel 

Face-to-Face

Communications

Fire 

Operations Branch

Y Fire Dept

VHF Fire Tac 1

Medical 

Branch

UHF Med 2

Hazmat

Branch

VHF Interop

VTAC 3

EOD

Branch

Trunked PD

Tac 7

Law Enforcement

Branch

X Police Dept

Trunked PD Tac 5

Traffic Group

X Police Dept

Trunked PD Tac 5

Trunked PD Tac 9

Crowd Control Group

Y Police Dept

Trunked PD Tac 5

Trunked PD Tac 10 Bomb Group

Trunked PD Tac 7

Trunked PD Tac 9

Bomb Techs

Trunked PD Tac 9

Highway Patrol

EOD

Trunked PD Tac 9

Swapped Radios

Entry

Group

VHF Interop

VTAC 3

Decon

Group

VHF Interop

VTAC 3

Triage

Group

UHF Med 2

Treatment

Group

UHF Med 2 North Traffic

Division

Sheriff Dept

UHF Sheriff Tac 2

Patch

Sheriff Tac 3

To

PD Tac 9

South Traffic

Division

Trunked PD Tac 8

Transportation

Group

UHF Med 2

North Division

X Fire Dept

VHF Tac 1

East Division

Y Fire Dept

VHF Tac 1

West Division

Y Fire Dept

VHF Tac 1

South Division

Y Fire Dept

VHF Tac 1

Incident

Command Team

Joint/Unified 

Command
Section 8 |Interoperability 71

capacity for unforeseen events. Shared or patched 

channels can be used when there are common 

tactical objectives. Before patching channels 

or using gateways that essentially tie channels 

together, the amount on each of the channels 

must be considered. If both of the channels are 

near saturation, the patch or gateway will make 

communications nearly impossible. Below is an 

example of a large-scale multidiscipline Command 

structure where multiple technologies are used to 

achieve interoperability.

Many technologies are available to achieve 

interoperability, and often the simplest solutions 

are overlooked in favor of complex technological 

solutions. The simple solutions usually are the 

quickest to implement and easiest to understand. In 

some instances, face-to-face communications may 

provide the desired level of interoperability, while 

in other cases other methods may be necessary. 

In Figure 8.3, a joint Command structure in a 

common location allowed the use of face-toface communications for coordination. When a 

common Command location is not employed, a 

strategic-level Command channel is an option.

Many technologies are used to achieve 

interoperability, and many other factors have an 

impact on interoperability. SAFECOM is a program 

within the U.S. DHS that is tasked with achieving 

communications interoperability for local, tribal, 

state and federal emergency response agencies. 

SAFECOM has many documents available that 

will guide and assist in achieving interoperability. 

SAFECOM documentation is available at http://

www.dhs.gov/safecom. 

Summary — Interoperability 

DHS SAFECOM definition: “The ability of 

Public Safety responders to share information 

via voice and data communications systems 

on demand, in real time, when needed, and 

as authorized.” 

Interoperability refers to the ability of emergency 

responders to work seamlessly with other 

disciplines, jurisdictions, systems or products 

without any special effort.

The NIFOG37 is a comprehensive listing 

of interoperability frequencies. The guide 

lists frequencies for federal and nonfederal 

interoperability in all bands. It is a common 

practice and advisable to include these frequencies 

in standard radio programming templates. This 

allows interoperability between disciplines, 

jurisdictions and multiple levels of government — 

federal, state, county and local.

The Interoperability Continuum is a tool developed 

to respond to an event and address all elements 

needed to achieve optimal interoperability. 

Interoperability can be intradiscipline or 

interdiscipline:

Intradiscipline:

•	 Like disciplines such as fire department to 

fire department or law enforcement to law 

enforcement.

•	 Common tactical objectives.

•	 Common language and terminology.

•	 Easiest to achieve.

Interdiscipline:

•	 Different disciplines such as fire department to 

law enforcement.

•	 Different tactical objectives and priorities.

•	 Different terminology.

Communications Unit

The use of a Communications Unit has proven 

to improve interoperability on incidents. The 

Communications Unit consists of:

•	 COML: This position is tasked with the 

management of communications on the 

incident.

•	 COMT: This position is the technical person 

assigned to implement technologies.

•	 INCM: This position manages the 

communications center functions.

•	 RADO: Communicates on assigned radio 

channels.

37 http://www.dhs.gov/national-interoperability-field-operations-guide.
Voice Radio Communications Guide 72 for the Fire Service

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Section 9 | 73

Radio Spectrum 

Licensing and the Federal 

Communications Commission

SECTION 9 — 

Radio Spectrum Licensing and the Federal Communications Commission

The FCC is an independent agency of the U.S. 

government established by the Communications Act 

of 1934. It is made up of seven bureaus, organized 

by function, that are responsible for various 

communications areas. The bureau that is most 

involved in public safety issues is the Public Safety 

and Homeland Security Bureau (PSHSB), which:

... is responsible for developing, 

recommending, and administering the 

agency’s policies pertaining to public 

safety communications issues. These 

policies include 911 and E911; operability 

and interoperability of public safety 

communications; communications 

infrastructure protection and disaster 

response; and network security and 

reliability. The Bureau also serves 

as a clearinghouse for public safety 

communications information and takes the 

lead on emergency response issues.

As this description implies, the PSHSB is 

responsible for rulemaking, licensing, education 

and outreach to public safety agencies. Portions 

of the activities of the PSHSB were previously 

carried out by the Wireless Telecommunications 

Bureau, particularly the rulemaking and licensing 

functions. The outreach and coordination functions 

were added to create a single bureau to handle all 

public safety issues.

The rules established by the FCC are located in 

CFR Title 47. The section of these regulations that 

applies directly to LMR systems used by public 

safety entities is located in Part 90 of 47 CFR. The 

Part 90 rules govern the operation of radio systems, 

as well as the frequencies available for use, what 

types of agencies are eligible to use the frequencies, 

and the procedures for licensing these frequencies.

While the FCC provides licensing and spectrum 

management for nonfederal users, the NTIA is the 

federal coordinating body. “Many Federal agencies 

use radio frequency spectrum to perform vital 

operations. NTIA manages the federal government’s 

use of spectrum, ensuring that America’s domestic 

and international spectrum needs are met while 

making efficient use of this limited resource.”38

“NTIA is also collaborating with the Federal 

Communications Commission to make available a 

total of 500 megahertz of federal and nonfederal 

spectrum over the next 10 years for mobile and 

fixed wireless broadband use. This initiative, 

to nearly double the amount of commercial 

spectrum, will spur investment, economic growth, 

and job creation while supporting the growing 

demand by consumers and businesses for wireless 

broadband services.”39

The use of RFs by the federal government, and 

those operating under federal authority such as 

national Urban Search and Rescue teams, is given 

by the Office of Spectrum Management (OSM) in 

the NTIA, a part of the Department of Commerce. 

The FCC does not set rules for use of radio 

spectrum by federal users but does coordinate 

use with the NTIA according to international 

law. While nonfederal agencies are not subject to 

NTIA regulation, they may be affected by these 

rules through partnerships and interoperability 

agreements, and all operations are subject to the 

authority under which they operate. 

Rulemaking

When the FCC believes that a change is needed to 

the rules, generally it will first issue a Notice of 

Inquiry (NOI) asking for general information on the 

issues related to the change. Next, the commission 

will issue a Notice of Proposed Rulemaking (NPRM) 

outlining the proposed rule change. The NPRM 

allows the public to comment on the proposed 

change and proposed modifications. After the FCC 

reviews the comments and proposals, it may issue 

one or more Reports and Orders (R&O) that provide 

the final details on the rule changes. This process 

may repeat as necessary to refine the rule change. 

In addition, a type of appeals process is allowed, 

known as a Petition for Reconsideration. During the 

process, public presentations, comment documents, 

and expert testimony are heard by the FCC. Fire 

departments and professional organizations may 

participate in all portions of the process.

38 http://www.ntia.doc.gov/category/spectrum-management.

39 http://www.ntia.doc.gov/category/spectrum-management.
Voice Radio Communications Guide 74 for the Fire Service

Licensing

The FCC also governs the licensing of RFs to 

agencies, and this process is handled separately 

from the rulemaking process, although issues that 

arise during the licensing process may result in 

future rule changes.

The licensing process starts with the agency 

defining the requirements for communications 

systems, including the type of radio system, the 

frequency band needed, the number of users that 

will use the proposed system, and the number of 

frequencies or frequency pairs required.

After the requirements are defined, the agency 

finds the specific frequencies through a frequency 

search conducted by the agency, a consultant or 

a manufacturer. The FCC website has tools to 

help agencies search for frequencies, including 

the Universal Licensing System (ULS), which is 

used to search for existing licenses, as well as for 

processing applications. The ULS also can be used 

to search for other agency licenses for examples on 

preparing a new license. Specific design parameters 

will be required to license the frequencies, 

including the transmitter locations, tower height, 

antenna height, and transmitter power output. 

Transmitter power output must be specified as 

“Effective Radiated Power,” which increases the 

actual power output from the transmitter by a gain 

factor specific to the antenna used in the system.

After all the system parameters and frequencies are 

determined, an application for license is prepared 

and sent to a frequency coordinator. The FCC 

requires that almost all applications for two-way 

or paging radio station licenses be reviewed by a 

FCC-certified frequency coordinator before the 

applications can be submitted to the FCC. The 

coordinator performs many functions for both 

the applicant and the FCC. The coordinator can 

assist the applicant in the selection of channels 

and equally importantly ensure that all requested 

channels can be used without causing unacceptable 

interference to other licensees. The coordinator 

also reviews the entire application for accuracy, 

including information about the applicant, the 

proposed radio site and facilities, and compliance 

with applicable FCC rules and regulations. 

The FCC created two radio service pools of 

channels, the industrial/business (I/B) pool and 

the public safety (PS) pool. The FCC recognized 

that mission critical communications require 

different coordination standards than general 

business channels that are heavily shared and 

certified different coordinators for each pool. To 

the extent possible, PS channels are coordinated to 

be either exclusive/semiexclusive in an area or to 

match regional and state plans for interoperability. 

Within the PS pool, there are several subcategories: 

(Each subcategory has been assigned a twoletter identifier.)

•	 Police (PP).

•	 Fire (PF).

•	 Forestry conservation (PO).

•	 Highway maintenance (PH).

•	 Special emergency (PS).

•	 Emergency medical (PM).

•	 General use channels (PX).

Except for PX channels, the FCC recognizes a 

home coordinator for each subcategory. The home 

coordinator has traditionally been the nonprofit 

association that represents the licensees in 

each category. 

For the PS pool, the FCC has certified four 

frequency coordinators, as follows: 

•	 PP: APCO. 

•	 PF: IAFC/International Municipal Signal 

Association (IMSA). 

•	 PO: Forestry Conservation Communications 

Association (FCCA). 

•	 PH: American Association of State Highway and 

Transportation Officials (AASHTO). 

•	 PM/PS: IAFC/IMSA. 

•	 PX: Any of the above. 

The FCC allows any of the four certified coordinators 

to coordinate any public safety subcategory, but 

requires that if the coordinator is not the home 

coordinator, advice and consent are received from 

the home coordinator. The coordinators have settled 

on a $100 fee per channel, called an interservice 

fee, for the home coordinators’ review. While other 

coordinators can coordinate a PF channel, the 

applicant will pay an extra $100 for that coordination 

versus having the coordination performed by IAFC. 
Section 9 | 75

Radio Spectrum 

Licensing and the Federal 

Communications Commission

In addition, the IAFC rate for coordinating a PF 

channel is the lowest of the rate cards for any of the 

coordinators. It just makes good economic sense 

to use IAFC for coordination of fire or general use 

channels. And, because of its partnership with IMSA, 

as described below, interservice fees also do not 

apply to PM/PS channels. 

Once the application passes the frequency 

coordination process, the application is submitted 

to the FCC through the automated ULS. While 

the FCC does not charge public safety agencies 

for licenses, there is a cost associated with the 

frequency coordination. Agencies can enter the 

license information into the ULS and track it as 

it proceeds. The FCC uses a computer system to 

perform automated checks on the license and then 

will assign the license request to an examiner who 

will perform more extensive checks on the details 

of the application. The examiner then will either 

grant the license or return it to the applicant for 

modification or additional documentation. If the 

request does not conform to FCC rules, it may be 

rejected outright and will require a reapplication.

If the application does not conform to the FCC 

rules in Part 90, the applicant may request a waiver 

of the rules. The waiver process is complicated, and 

waivers are not granted frequently. An example of 

a waiver that has been granted is the use of UHF 

TV Channels 14 and 16 for public safety use in 

the New York and Los Angeles metropolitan areas. 

These areas had significant needs for additional 

frequencies in the 1980s, before the 700 MHz and 

800 MHz public safety bands were established. The 

agencies involved presented the needs along with 

extensive documentation on why the needs could 

not be fulfilled with current frequency allocations. 

Departments that wish to pursue a waiver must 

present a detailed, well-thought-out case to 

be successful. 

Federal Communications Commission Actions 

to Increase Public Safety Spectrum

Historically, all public safety systems used 

frequencies in the VHF low, VHF high, and UHF 

bands, with the systems progressing to higher 

frequencies as technology improved. Many fire 

and police departments in the U.S. still use radio 

systems in the VHF and UHF bands and have 

no plans to move to other bands. However, 

the population growth in large metropolitan 

areas has created rising demand for more RFs. 

In many areas of the country, all available VHF 

and UHF frequencies are assigned to agencies, 

leaving no space for growth. The FCC, working 

with equipment manufacturers and public safety 

communications organizations, has developed 

several programs to increase the available 

frequencies for public safety communications. 

National Public Safety Planning Advisory Committee

The first major expansion of frequencies allocated 

to public safety took place in 1986 when the 

FCC created the National Public Safety Planning 

Advisory Committee (NPSPAC) to develop 

frequency allocations on the 800 MHz band. Prior 

to the NPSPAC process, public-safety-licensed 

frequencies in the 800 MHz band were combined 

with commercial business and cellular companies, 

and the available frequencies were very limited. 

The NPSPAC frequencies were put under the 

control of 55 Regional Planning Committees 

(RPCs). The RPCs are responsible for creating 

regional frequency plans that take into account 

agency needs, including metropolitan, rural, 

and statewide, and are responsible for initial 

coordination of applications.

Narrowbanding Below 512 Megahertz

The NPSPAC process provided additional frequency 

spectrum for new systems operating in the 800 

MHz band, but most fire and police departments 

in the U.S. still operate in the VHF or UHF bands 

(Figure 9.1). To increase the available frequency 

spectrum for public safety in the VHF and UHF 

bands, the FCC began investigation into narrowing 

the bandwidth for frequencies in this band. 

In the VHF band, channels were spaced 15 kHz 

apart, with transmitters operating with 25 kHz 

bandwidth. In addition, as shown in Figure 9.1,

adjacent transmitters were separated geographically 

to minimize interference. It became apparent that 

as the population served by these departments 

grew, their spectrum needs would grow as 

well, and the existing band plan would become 

inadequate for the needs.
Voice Radio Communications Guide 76 for the Fire Service

Figure 9.1. Before Narrowbanding

150.815 150.830 150.845 150.860 150.875 150.890 150.905

Original VHF channels spaced at 30 kHz intervals.

Geographically separated VHF channels spaced

15 kHz from original VHF channels.

With no unused spectrum available in these bands, 

the FCC proposed narrowing the bandwidth of 

the existing frequency assignments, dividing each 

existing frequency channel in half (Figure 9.2).

Each frequency in the new plan was spaced 7.5 kHz 

from the previous and had a bandwidth limited to 

12.5 kHz. 

Figure 9.2. After Narrowbanding

150.815

150.8225 150.8375 150.8525 150.8675 150.8825 150.8975

150.830 150.845 150.860 150.875 150.890 150.905

Old 25 kHz bandwidth channels spaced at 30 kHz intervals

Old 25 kHz bandwidth channels spaced at 15 kHz from the original channels

12.5 kHz bandwidth channels at 7.5 kHz spacing from existing channels

The FCC developed a schedule in 1995 for 

migration from the current band plan to the 

new narrowband plan. This plan is often called 

“refarming” to relate it to changing the crops in 

a field. The schedule for refarming established 

by the FCC was divided into phases, with each 

phase increasingly restricting the use of wideband 

systems to encourage migration to narrowband. 

The first phase began in 1997 with the FCC 

denying certification for equipment that operated 

with 25 kHz bandwidth if it did not also operate at 

12.5 kHz or equivalent bandwidth. This prevented 

manufacturers from making equipment that would 

not be able to be used once the future phases 

came into effect. The FCC predicted that most 

(wideband) equipment manufactured before this 

date would become obsolete and unserviceable 

before the mandatory narrowband deadline.
Section 9 | 77

Radio Spectrum 

Licensing and the Federal 

Communications Commission

At the time of this original order, the FCC also 

made other orders with respect to expansion of 

existing systems, creation of new systems, and the 

manufacture and importation of equipment. These 

orders staggered the restrictions over several years 

in an attempt to make the transition to narrowband 

communications less painful to local agencies. 

Unfortunately, the complexity of the rules confused 

many agencies and in 2004, before the new rules 

took effect, the FCC modified the order to have two 

deadlines, one in 2011 and the other in 2013.

In January 2011, the FCC stopped accepting 

applications for new systems, modifications to 

existing systems, and transmitters that operated 

using a bandwidth greater than 12.5 kHz or 

equivalent. In addition, the FCC prohibited the 

manufacture or import of radio equipment that 

was capable of operating on a bandwidth greater 

than 12.5 kHz or equivalent.

The final phase began in January 2013, and it 

prohibited the operation of radios and radio 

systems that did not comply with the narrowband 

requirements. All radios, portable, mobile, repeaters, 

and base stations that operated in the VHF or UHF 

bands would be replaced, and the systems they 

operated in would be redesigned by this date.

The FCC’s actions to refarm the VHF and UHF 

bands resulted in perhaps the most confusing set of 

orders ever from the FCC concerning public safety 

communications, resulting in many unnecessary 

system replacements. These replacements included 

departments transitioning to systems that did not 

meet their operational needs and were unnecessarily 

costly to procure, operate and maintain. Agencies 

were able to keep existing communications systems 

that were used for years, provided that they 

modernized the equipment and system design by 

transitioning to 12.5 kHz bandwidth frequencies 

and equipment prior to 2013.

Further Narrowbanding

The FCC has proposed further narrowing the 

bandwidth of channels below 512 MHz to 6.25 

kHz bandwidth but has not issued rules related to 

a forced migration to this narrower bandwidth at 

the time of this publication. One of the reasons 

for this is the lack of FDMA subscriber equipment 

capable of operating at this narrower bandwidth. In 

the UHF and 700/800 MHz bands, repeater pairs 

are preallocated, leading to a simpler TDMA system 

implementation. In the VHF bands, there are no 

predefined transmit/receive pairs, making it difficult 

to aggregate sufficient channels to provide for fouror two-slot TDMA repeated systems. If spectrum use 

pressure continues, expect that the FCC will again 

visit the issue of narrowbanding below 512 MHz.

Public Safety Wireless Advisory Committee

Although the NPSPAC process provided additional 

frequencies in the 800 MHz band, the need for 

more capacity became evident in the early 1990s. 

This increasing need for more frequency spectrum 

was not limited to nonfederal agencies, as the 

federal government had not made modifications 

to federal agency needs in many years. The FCC 

established the PSWAC in 1993 under direction 

from Congress to address the RF spectrum needs of 

federal, state and local agencies over the next five 

years, and over the next 15 years. The goal was to 

develop a plan to allocate additional spectrum for all 

users, as well as establish plans for communications 

interoperability between all levels of government.

The final report of the PSWAC recommended 

the allocation of 2.5 MHz of spectrum below 

512 MHz for federal, state and local public safety 

interoperability, and the addition of approximately 

25 MHz of new spectrum over the next five years 

and 70 MHz over 15 years for federal, state and 

local public safety use. Although to date only 

approximately one-third of the new spectrum 

requested has been allocated for state and local 

public safety use, this is more than any request in 

the last 20 years.

700 Megahertz Spectrum Allocation

As a result of the PSWAC’s recommendation that 

additional spectrum be allocated to public safety, 

the FCC allocated 24 MHz of new spectrum. This 

allocation, from 764 MHz through 776 MHz 

and 794 MHz through 806 MHz, was part of the 

spectrum previously allocated to TV Channels 

60 through 69. This spectrum became available 

for use by public safety through the transition of 

television stations to digital systems. This portion 

of spectrum was chosen because it was adjacent 
Voice Radio Communications Guide 78 for the Fire Service

to the existing 800 MHz band also used for public 

safety communications, and radio equipment could 

be designed easily to operate in both bands.

The FCC issued an order that described the rules 

for the use of the new frequency band, as well as 

the new band plan in 1998. The order split the 

allocation of frequencies into four basic classes:

•	 General-use frequencies.

•	 State frequencies.

•	 Interoperability frequencies.

•	 Wideband frequencies.

The general-use frequencies could be licensed by 

both state and local entities, and the allocation and 

use of the channels would be governed by an FCCapproved regional plan developed by stakeholders 

in the region. The state frequencies would be 

licensed to each state and would be allocated in 

any manner the state desired. The interoperability 

frequencies could be licensed by state, local 

and, to a limited degree, federal agencies, and 

the allocation and use of the frequencies would 

be governed by a plan produced by a State 

Interoperability Executive Committee (SIEC) in 

each state. The wideband channels were intended 

to provide the ability to develop regional and local 

high-speed data systems.

The FCC reconfigured the 700 MHz band plan 

in 1997, which modified the public safety 

narrowband (primarily voice) spectrum to be 

located at 769-776/799-805 MHz. The previously 

designated wideband spectrum was reconfigured 

and redesignated for broadband operation, with a 

guard band between broadband and narrowband 

spectrum segments. Subsequently, the public safety 

community, including the fire service, fought for 

and successfully obtained an additional 10 MHz 

of spectrum for broadband operation to support 

video and data. In summary, the 700 MHz band 

for public safety now consists of a total of 12 MHz 

for voice with a total of 20 MHz for broadband 

high-speed data and imaging, and 2 MHz dedicated 

to guard band between the voice and broadband 

operations to help minimize interference.

800 Megahertz Reconfiguration

The initial frequency allocations in the 800 MHz 

band were made available in 1974 by reallocating 

the frequencies used by TV Channels 70 through 

83. This spectrum was available for use by public 

safety, business and industrial users, and cellular 

systems. The FCC allocated 70 channels to public 

safety and interleaved these with other channels for 

business and industrial users. Interleaving means 

that one channel was allocated to business, the 

next for industrial, and the next for public safety. 

This repeated, creating an allocation layered with 

public safety sandwiched between other users. 

Every public safety channel had a nonpublic-safety 

system on either side. Later, many of these channels 

were allocated to Specialized Mobile Radio (SMR) 

systems, which are private trunked radio systems 

used by businesses. Figure 9.3 shows the interleaved 

frequency allocation, with SMR systems on either 

side. The 800 MHz NPSPAC band is the block 

labeled Public Safety to the right of the Upper 200 

Enhanced Specialized Mobile Radio (ESMR) block.

Figure 9.3. 800 MHz Band Before Reconfiguration

Mobile and Control Station Transmit Frequencies (in MHz)

Base Station Transmit Frequencies (MHz)

806 816

861

821

866

824

869

809.75

851 854.75

General

Category

Interleaved Spectrum

(inc. Nextel)

ESMR (Nextel)

(Upper 200)

NPSPAC

(Public

Safety)

In the early 1990s, FleetCall (later to become 

Nextel) started to develop a digital SMR network 

that incorporated the same features as cellular 

systems. This system used frequencies in the SMR 

bands, as well as frequencies in the interleaved 

band. Traditional cellular systems were not allowed 

to operate in these bands, but FleetCall received 

waivers from the FCC to operate the new system. 

At the same time, the deployment of cellular 

systems was increasing at a rapid pace.

One of the two bands assigned to cellular systems, 

the Cellular A band, is directly adjacent to the 

NPSPAC 800 MHz band. The NPSPAC band is also 

adjacent to the Upper SMR band. With FleetCall 

systems on both sides of the interleaved band, and 

this and other systems interleaved — along with 

SMR systems and cellular sandwiching the NPSPAC 

band — public safety systems were in a bad place. 

Both the FleetCall system and cellular systems are 

designed with a large number (30 or more) of 

transceiver sites throughout the system’s coverage 
Section 9 | 79

Radio Spectrum 

Licensing and the Federal 

Communications Commission

area. Compare this with the typical public safety 

system with one or two sites. The public safety 

systems were bound to have interference, but 

none of the system operators that were likely to 

interfere with the public safety systems recognized 

the potential.

By the late 1990s, the interference problem with 

public safety systems in the 800 MHz band 

had become well-recognized, and agencies 

were demanding action to restore the ability to 

communicate on emergency incidents. To its credit, 

the FCC began a process to classify the problem 

and find a solution. At that time, the FCC ordered 

that systems operators in the affected bands must 

take steps to minimize interference effects in 

2004. The FCC also ordered that the 800 MHz 

band would be reconfigured to further minimize 

the interference from Nextel and Cellular A band 

systems under a process known as “rebanding.”

Under the rebanding process, Nextel was to fund 

the effort of relocating existing systems in an 

equitable manner and in return would receive 

additional frequencies in the 1.9 MHz band. To 

supervise the rebanding process, the FCC appointed 

an independent consulting company, BearingPoint, 

as the Transition Administrator (TA). The TA had the 

responsibility of managing the process, including 

establishing the schedule, monitoring the process, 

and facilitating resolution of conflicts. The process 

was divided into four “waves” that grouped together 

the regions that would be reconfigured. All waves 

were scheduled to be reconfigured by the end of the 

second quarter of 2008 with the exception of Wave 

4, which contained U.S./Canada or U.S./ Mexico 

border areas. The reconfiguration of these areas was 

subject to treaty negotiations that delayed the process.

Figure 9.4. 800 MHz Band After Reconfiguration

Mobile and Control Station Transmit Frequencies (in MHz)

Base Station Transmit Frequencies (MHz)

806 815 816 817

860 861 862

824

869

809

851 854

Public Safety

B/ILT

Noncellular SMR

Expansion 

Band 

Guard

Band

ESMRel

NPSPAC

(Public

Safety)

The reconfigured band in Figure 9.4 shows that 

the public safety portions of the new band would 

be isolated from the ESMR portion of the band 

where Nextel operated. In addition, the NPSPAC 

band had been relocated away from the Cellular A 

band and was much less likely to suffer significant 

interference from nonpublic-safety systems.

T-Band

The T-Band supplies a significant number of 

channels to support public safety operations as 

well as regional interoperability to 11 of the largest 

metropolitan areas. The 11 metropolitan areas are 

Boston, Chicago, Dallas, Houston, Los Angeles, 

Miami, New York, Philadelphia, Pittsburgh, San 

Francisco and the District of Columbia (Figure 9.5). 

The T-Band lies within the UHF spectrum between 

470-512 MHz. As a result of the Middle Class Tax 

Relief and Job Creation Act of 2012, the FCC was 

ordered to recover and auction the T-Band spectrum 

by February 2021. Within two years of the auction 

close (early 2023), the FCC is required to clear public 

safety operations from this portion of the band. 

Currently, the FCC has placed a freeze on all new 

expanded T-Band operations for public safety and 

industrial and business operations. The challenge 

now is to remove all public safety off the T-Band, 

which is proving to be costly and complex due to 

spectrum allocation.

Figure 9.5. T-Band Locations

Amount of T-Band Spectrum

Boston (12 MHz)

Chicago (12 MHz)

Dallas/Fort Worth (6 MHz)

Houston (6 MHz)

Los Angeles (24 MHz)

Miami (6 MHz)

New York/NJ (18 MHz)

Philadelphia (12 MHz)

Pittsburgh (12 MHz)

San Francisco (12 MHz)

Washington DC/MD/VA (12 MHz)

Public Safety portion of

this spectrum varies by market

x

x

x

x

x

x

x

x x

x x

Stu Overby, NPSTC Presentation, APCO Int’l, T-Band Background and 

NPSTC Report Summary, Aug. 21, 2013 

In March 2013, NPSTC convened a T-Band working 

group to study the giveback and its implications 

for public safety communications, including the 

potential costs of relocation efforts. The full report 

is available on the NPSTC website and cites costs, 

spectrum alternatives, and limited spectrum 

gains as potential limitations (SAFECOM T-Band 

Giveback pp.1-2).
Voice Radio Communications Guide 80 for the Fire Service

The migration from T-Band presents a number 

of problems for local jurisdictions and their 

public safety responders. The two biggest issues 

are the likelihood that funding generated by the 

spectrum auction will not be sufficient to pay for 

the migration and that there may not be sufficient 

alternate spectrum available in these busy metro 

areas to migrate to. In the Boston area alone, over 

6,000 public safety radios operate on the T-Band.

A 2015 study commissioned by the IAFF concluded 

that there were over 700 jurisdictions that would 

be impacted by the changes to T-Band use by their 

fire, EMS, and law enforcement responders. 

A requirement of the act is that proceeds are to 

assist with spectrum relocation. However, the 

proceeds will not cover all costs associated with 

this. An estimate from 2013 expects costs to 

exceed 5.9 billion dollars for spectrum relocation 

(Figure 9.6). Private sector relocation costs are not 

considered, which may decrease the percentage 

of auction funding to be used for public safety 

spectrum reallocation.

Figure 9.6. Breakdown of the $5.9 Billion in Costs

System

Sites

Repeaters

Subscribers

Other

Planning

8%

13%

23%

16%

22%

18%

Licensees are required by law to migrate from the 

T-Band spectrum to another unidentified spectrum. 

There are limited options for a replacement 

spectrum. The VHF, UHF and 700/800 MHz bands 

have few available channels. However, in response 

to Public Law 112-96, the FCC issued rules and 

guidance related to the required T-Band transition. 

On Oct. 17, 2014, the FCC released the narrowband 

reserve channels (24 12.5 kHz channels) to general 

use under the administration of the RPC for the 

benefit of state and local public safety users. Public 

safety users still rely on LMRs for communication. 

At the time of this publication, Voice over LTE 

(VoLTE) and the National Public Safety Broadband 

Network (NPSBN) are not suitable options for 

mission critical voice for public safety users.

FCC Public Notice Jan. 9, 2015.

•	 A five-year priority access window for T-Band 

incumbents to license the former reserve 

spectrum (from Jan. 9, 2015 to Jan. 9, 2020).

•	 The date for filing RPC Plan Amendments 

to incorporate the former reserve spectrum 

(June 2, 2015).

•	 The date by which certain licensees must 

reprogram their deployable trunked systems to 

operate on the former reserve channels. (See 

FCC Public Notice DA 15-34 for specific dates.)

The FCC requires that T-Band incumbents seeking 

reserve channels (1) commit to returning to the 

Commission an equal amount of T-Band spectrum 

and (2) obtain RPC concurrence.

Grant Guidance

OEC encourages states to update Statewide 

Communications Interoperability Plans (SCIPs) to 

address FCC directives affecting current or planned 

public safety communications systems, including 

T-Band migration, and has advised grantees to 

consult the FCC, their SWIC, and their frequency 

coordinator during project planning to ensure 

projects or upgrades planned for systems operating 

in the T-Band are coordinated and align with the 

state’s migration plans.

The following (Figure 9.7) is an example timeline 

providing proposed steps for transitioning to a 

new system.
Section 9 | 81

Radio Spectrum 

Licensing and the Federal 

Communications Commission

Figure 9.7. Sample T-Band Giveback Transition Timeline

Develop Base

Requirements

Identify

Available

Spectrum

License 

Available

Spectrum

Site Selection

With Community

and Zoning

Officials

Transition to

New System

Decommission

Old System

Issue

RFP

Proposal

Development/

Response From

Vendors

Review Vendor

Proposals

Draft Request

for Proposal

(RFP)

Develop

Detailed

System

Requirements

Negotiate

Contract With

Vendor(s)

Test System

Components

Deploy 

System

Award

Contract

Identify Possible Funding

Sources (bonds, general

fund, fees, partnership)

Develop Final 

System Design

Test System

Determine

Funding

Source

Identify

Need for 

New System

Approve

Funding Source

Selection

Determine

Funding

Source

Legal/

Statutory Approval

for RFP

Identify

Potential

Vendors

Approve Final

System Design

Approve System

Test Plan

System

Acceptance

Start Year 1 Year 2

Year 3

Year 6

Year 5

Year 7

Year 4

Select

Vendor

Build System

Components

SAMPLE T-BAND GIVEBACK TRANSITION TIMELINE

The following is an example timeline providing proposed steps for transitioning to a new system. 

Summary — Radio Spectrum Licensing and 

the Federal Communications Commission

One problem that is common to all 

recommendations for increasing the spectrum 

allocated to public safety agencies is accurately 

defining “public safety agencies.” Another lies in 

the politics of the allocations. Many state and local 

governments, and their communications managers 

in particular, lobbied to include “public service” or 

“public safety support” agencies in those eligible to 

license spectrum allocated to public safety.

The result of this is that agencies that do not 

support the emergency response aspect of public 

safety are eligible for licenses under the new 

rules. This includes such diverse groups as school 

bus companies, road and highway maintenance 

crews, and public solid-waste disposal agencies. In 

essence, any state or local government workgroup 

is eligible for licensing spectrum allocated to 

public safety, no matter how removed the agency 

is from emergency response activities. The benefit 

to state and local governments is that they can 

build communications systems that support all 

divisions with spectrum allocated to public safety. 

Unfortunately, this is done by exploiting the 

public’s understanding of what falls under the 

umbrella of public safety and ultimately reducing 

the spectrum available for emergency response.

Not all of the responsibility for the lack of 

adequate spectrum for public safety response 

lies with the FCC or the various coordinating 

agencies. Public safety agencies themselves often 

perpetuate this inadequacy through their actions 

(or inactions). The insistence by many agencies 

to maintain “stovepipe” communications systems 

that duplicate the coverage of other systems and 

do not operate with neighboring agencies is one 

of the most egregious examples. The efficiency of 

frequency use could be increased dramatically if 

all agencies were committed to cooperative system 

development with the goal of maximum frequency 

use among all agencies in a system. 

The FCC and communications equipment industry 

are driven by the need to accommodate additional 

users in a limited amount of radio spectrum and 

economic forces. Any technical change to spectrum 

use requirements has the possibility to affect 

the operational performance of a radio system, 

negatively or positively. The fire service has an 

opportunity to be a part of the solution to this issue 

through coordinated, organizational participation in 

the process. If the fire service cannot communicate 

its needs, or if the fire service voice is fragmented, 

then a solution will be imposed by others, and 

it is unlikely that that solution will meet all the 

operational needs of the service.
Voice Radio Communications Guide 82 for the Fire Service

The FCC was ordered to recover and auction the 

T-Band spectrum by February 2021. Within two 

years of the auction close (early 2023), the FCC is 

required to clear public safety operations from this 

portion of the band.

•	 A five-year priority access window for T-Band 

incumbents to license the former reserve 

spectrum (from Jan. 9, 2015 to Jan. 9, 2020).

•	 The date for filing RPC Plan Amendments 

to incorporate the former reserve spectrum 

(June 2, 2015).

•	 The date by which certain licensees must 

reprogram their deployable trunked systems to 

operate on the former reserve channels. (See 

FCC Public Notice DA 15-34 for specific dates.)

The T-Band supplies a significant number of 

channels to support public safety operations as 

well as regional interoperability to 11 of the largest 

metropolitan areas. The 11 metropolitan areas are 

Boston, Chicago, Dallas, Houston, Los Angeles, 

Miami, New York, Philadelphia, Pittsburgh, San 

Francisco and the District of Columbia. 
Section 10 | FirstNet 83

SECTION 10 — 

First Responder Network Authority or FirstNet

History

Nationwide Public Safety Broadband Network

In December 2006, the FCC made a statement of 

opinion in an NPRM: 

We believe that the time may have come 

for a significant departure from the 

typical public safety allocation model the 

Commission has used in the past ... While 

this system has had significant benefits for 

public safety users, in terms of permitting 

them to deploy voice and narrowband 

facilities for their needs, the system has 

also resulted in uneven build-out across the 

country in different bands, balkanization 

of spectrum between large numbers of 

incompatible systems, and interoperability 

difficulties if not inabilities.

This statement predicted the activities that would 

occur in April and June 2007, with the FCC’s 

Proposed Rulemaking and Second Report and 

Order on the 700 MHz band. In this rulemaking, 

the FCC proposed to create a nationwide public 

safety broadband data system by rebanding the 

700 MHz public safety band to reallocate the 10 

MHz wideband frequency allocation and combine 

this with 10 MHz of new spectrum that would 

be auctioned. The FCC would allow a single 

nationwide licensee for the reallocated 10 MHz of 

existing spectrum and would auction the other 10 

MHz of new spectrum, known as the D Block.

The auction would seek to find a bidder that would 

purchase the rights to the 10 MHz of D Block 

spectrum and would then have the rights to combine 

this with the 10 MHz of public safety spectrum to 

form a nationwide commercial and public safety 

network. The FCC rules stated that the network must 

meet the requirements of public safety agencies and 

appointed the Public Safety Spectrum Trust (PSST) 

Corporation to represent the interests of public 

safety. The PSST developed a Bidder Information 

Document (BID) that outlined the requirements the 

new system must meet. These specifications included 

priority access for public safety users, backup power 

and networking requirements, and other features 

necessary to provide a high-reliability system. The 

PSST also became the licensee for the 10 MHz of 

reallocated public safety spectrum.

The D Block auction occurred along with other 

auctions in the first quarter of 2008. There was 

one bidder for the D Block, but the reserve price 

(minimum bid) set by the FCC was not met, and 

D Block was not auctioned successfully. After the 

auction, there was some discussion that the 

requirements for the system set forth in the BID 

created too much uncertainty as to the cost of 

constructing the system. This, along with the 

uncertainty of how many public safety agencies 

would participate, may have led to the 

unsuccessful auction. 

In January 2015, the AWS-3 radio spectrum auction 

was held and generated $44.9 billion. The proceeds 

of the auction provided the funding for FirstNet 

and will finance technological upgrades to 911 

emergency systems and contribute over $20 billion 

to deficit reduction.

When the nationwide broadband network is 

successfully built, it will be the first system of its 

size built specifically for public safety requirements 

and could serve as an evaluation model for a 

possible nationwide voice system in the future.

Formation of FirstNet

FirstNet40 is an independent authority within the 

U.S. Department of Commerce’s NTIA. “Signed 

into law (P.L. 112-96, Title VI) on February 22, 

2012, the Middle Class Tax Relief and Job Creation 

Act created the First Responder Network Authority 

(FirstNet). The law gives FirstNet the mission to 

build, operate and maintain the first high-speed, 

nationwide wireless broadband network dedicated 

to public safety. FirstNet will provide a single 

interoperable platform for emergency and daily 

public safety communications”41 (Figure 10.1).

40 http://www.firstnet.gov/about.

41 http://www.firstnet.gov/about.
Voice Radio Communications Guide 84 for the Fire Service

Figure 10.1. FirstNet Beginnings

As noted in Figure 10.1, FirstNet is managed by a 

15-member board of directors. The FirstNet board 

consists of:

•	 Secretary of Homeland Security (or designee).

•	 Attorney general of the U.S. (or designee).

•	 Director of Office of Management and Budget 

(or designee).

•	 Twelve individuals to be appointed by the 

Secretary of Commerce. 

•	 The appointments shall have:

– Not fewer than three individuals to 

represent collective interests of states, 

localities, tribes and territories.

– Not fewer than three individuals who have 

served as public safety professionals.

The board is responsible for the strategic decisions 

regarding the direction of FirstNet. 

In Figure 10.1, there is a 40-member PSAC that 

reports to the board on specific issues related to 

public safety operations. The members of this 

committee represent the voice of public safety 

and should be contacted regarding public safety 

issues. The listing of PSAC members can be found 

at http://www.firstnet.gov/about/public-safetyadvisory-committee.
Section 10 | FirstNet 85

Figure 10.2. FirstNet Organization With Appointees

FirstNet Organization

Sept. 30, 2015

Sue Swenson, Chair

Jeff Johnson, Vice Chair

Barry Boniface

Chris Burbank

Neil Cox

Ron Davis

James Douglas

Edward Horowitz

David Mader 

Kevin McGinnis

Annise Parker

Ed Reynolds

Suzanne Spaulding

Richard Stanek

Teri Takai

Chief Technical Officer (CTO)

JEFF BRATCHER (Acting)

Chief Admin. Officer (CAO)

FRANK FREEMAN

Chief Financial Officer (CFO)

KIM FARINGTON (Acting)

Office of Chief Counsel (OCC)

JASON KARP (Acting)

Claudia Wayne

Chris Algiere (Federal)

Jeremy Zollo (State/Local)

Kristi Wilde (SPOCs)

Chief Information Officer (CIO)

JIM GWINN

Board

Brian Hobson

Doug Harder

Carl Rebstock (Tribal)

Vicki Lee (Associations)

Josh Ederheimer (Law 

Enforcement)

Justin Shore

Thomas Shull

Jeanette Kennedy

Kyle Richardson

Natasha Marstiller

Director of 

State Plans

RICHARD REED

Director of Outreach

AMANDA HILLIARD

Director of 

Government Affairs

ED PARKINSON

Director of 

Communications 

RYAN OREMLAND

Director of 

State Consultation

DAVE BUCHANAN

Chief Executive Officer 

MICHAEL POTH

President

TJ KENNEDY

Chief User Advocacy Officer

TJ KENNEDY

As of Sept. 30, 2015, the FirstNet general manager 

reports the business of FirstNet to the board 

(Figure 10.2). The FirstNet organization is similar 

to a commercial telecommunications company.

As part of the act, FirstNet was allocated 20 MHz 

of frequency spectrum to manage for deployment 

of the Radio Access Network that is part of the 

FirstNet system.

As you can see in Figure 10.3, the frequencies 

allocated are near some of the commercial carriers. 

Part of the cost reduction and containment strategy 

is investigating options that would allow FirstNet 

to share access of the assigned spectrum with 

commercial providers. At present, it is being looked 

at as a creative way to maximize the use of the 

spectrum and create funding streams for future 

sustainment. It is important to note that if shared, 

provisions in the new LTE standards would provide 

Figure 10.3. Public Safety Allocation in the 700 MHz Band

BC 14

FirstNet Local

PS Entities FirstNet LocalPS Entities

BC 14

Downlink

Verzion

Uplink

Verzion

Public

Safety

5 MHz

BB2

Public

Safety

5 MHz

NB-V

Public

Safety

5 MHz

BB1

A-GB 1 MHz

PS-GB 1 MHz

B-GB 1 MHz

A-GB 1 MHz

Public

Safety

5 MHz

BB2

Public

Safety

5 MHz

NB-V

Public

Safety

5 MHz

BB1

PS-GB 1 MHz

B-GB 1 MHz

757758768769775776787788793805

806 MHz

763798799

746 MHz

Public Safety 700 MHz Allocations

Broadband Portion (10 x 10) 20 MHz

Total Allocation 34 MHz FirstNet = First Responder Network Authority

PS Entities = Public Safety Narrowband Licenses

 BB = Broadband

 N-V = Narrowband Voice (e.g., P25 systems)

 PS-GB = Public Safety Guardband

Narrowband Portion (6 x 6) 12 MHz

Guardband Portion (1 x 1) 2 MHz

Legend

FCC allocated spectrum to public safety for broadband data services

Commercial Mobile Carriers

FirstNet Frequency Allocation42

a mechanism to remove nonpublic safety from the 

frequencies in time of emergency. Public safety 

would always maintain priority in the system.

42 http://www.anritsu.com/en-US/Products-Solutions/Solution/Effectively-testing-700MHz-public-safety.aspx.
Voice Radio Communications Guide 86 for the Fire Service

“FirstNet was created to be a force-multiplier 

for first responders — to give public safety 21st 

century communication tools to help save lives, 

solve crimes and keep our communities and 

emergency responders safe. To do that, FirstNet 

will build a new Band Class 14 network designed to 

be reliable, functional, safe and secure, and provide 

optimal levels of operational capability at all times. 

For the first time, public safety communications 

will be based on commercial standards. This will 

bring the benefits of lower costs, consumer-driven 

economies of scale and rapid evolution of advanced 

communication capabilities.”43

In the future, FirstNet may provide a single 

interoperable platform for emergency and daily 

public safety communications. The FirstNet 

network will fulfill a fundamental data transport 

need of the public safety community as well 

as the last remaining recommendation of the 

9/11 Commission. 

FirstNet is a data system being developed to meet 

the needs of first responders. It is envisioned as a 

4G LTE system for public safety designed to be:

•	 Competitively priced.

•	 Highly survivable and accessible. 

•	 Secure.

•	 Public safety focused. Provide public safety 

functionalities, such as Mission Critical Voice. 

Cost

FirstNet has been allocated $7 billion for the buildout of the system. Telecommunications experts have 

differing opinions on the approach FirstNet will take 

to deploy the system, which will impact the system 

cost. While $7 billion is a large sum of money, it is 

a fraction of the cost that commercial carriers have 

invested in infrastructure. FirstNet is working with 

each state to develop requirements, inventory and 

available resources to share and identify the state 

stakeholder groups. FirstNet hopes to use sharing 

agreements to help contain build-out costs. 

FirstNet, like the commercial providers, will be 

a subscriber-based system. Public safety is not

mandated to move data transport to FirstNet. 

FirstNet will be in direct competition with the 

commercial providers and will have to demonstrate 

the added value to warrant additional cost to the 

public safety community. FirstNet is mandated to 

be self-sustaining. This will require it to charge 

subscription fees like the commercial carriers to 

maintain, operate and upgrade the network. The 

FirstNet tenet states “To offer services that meet the 

needs of public safety at a cost that is competitive 

and compelling to users.”

Accessibility

FirstNet is being designed to provide data access 

for public safety in times of emergency anywhere 

in the U.S. or U.S. territories. In recent history, 

the commercial systems have failed to provide 

connectivity when overwhelmed by spikes in usage 

from the general public. Current systems do not have 

priority built in to ensure public safety access during 

these high-traffic periods (Figure 10.4). This was 

documented during the Boston Marathon Bombing 

(April 2013) and the Virginia earthquake (August 

2011). In both incidents, the cell systems were unable 

to handle the intense demand for services. FirstNet 

will move public safety off the commercial systems 

and be designed to handle public safety traffic during 

similar events or incidents.

Figure 10.4. The Coverage Challenge

A component of accessibility is system coverage. 

The system is required to cover all population 

centers as well as rural and wilderness areas. 

System design will include fixed infrastructure 

and deployable infrastructure to achieve the 

coverage goals. Options to achieve the coverage 

43 http://www.firstnet.gov/network.
Section 10 | FirstNet 87

44 http://www.npstc.org/download.jsp?tableId=37&column=217&id=3066&file=Public_Safety_Grade_Report_140522.pdf.

goals also include possible spectrum sharing with 

commercial carriers, but no specifics will be 

available until the system design is completed. 

Survivability

Being a public safety system, FirstNet is being 

designed to survive extreme weather and seismic 

events. Public safety radio systems are expected to 

be operable when these events happen to maintain 

the ability to respond to the needs of the public. 

This equates to building the infrastructure to public 

safety standards that require redundant power 

sources, hardened sites, towers that will survive 

extreme weather, and back haul connections that 

will remain intact. The NPSTC recently released a 

document “Defining Public Safety Grade Systems 

and Facilities”44 that describes the Public Safety 

Grade. The document covers physical properties 

of the radio sites, antenna masts, connectivity 

requirements, redundant power sources, and many 

others. The document is a good reference for 

building voice radio systems sites as well.

Security

In this age of computer hacking, denial of service 

attacks, and data breeches, security is a key element 

of FirstNet. The system is being designed to provide 

data service for the law enforcement community 

as well as many other disciplines that have data 

security requirements. FirstNet is envisioned as 

a secure wireless data network with the security 

needed to allow transport of sensitive information. 

The elements of security are being developed but 

will be in place when FirstNet is deployed. 

Public Safety Focus

Mission Critical Voice is a capability that is 

under development. Mission Critical Voice was 

presented as a replacement for LMR systems. This 

is a capability that is being worked on and is not 

currently available. There are no definite dates 

for completion, and FirstNet has not been built. 

Based on these two factors, it is recommended to 

maintain current LMR systems until FirstNet and 

Mission Critical Voice are deployed. A component 

of Mission Critical Voice to be watchful for is 

off-network capabilities. FirstNet will operate a lot 

like the commercial systems today. We all realize 

that if we do not have system coverage, we do not 

have connectivity. Off-network communications 

is mandatory in the fire service application. If the 

system does not cover the interior of all buildings, 

which is a certainty, then off-network capability 

is required to maintain communications with 

all personnel on the fireground. The reason we 

use LMR systems is that they, in general, provide 

communications where commercial networks do 

not. For FirstNet Mission Critical Voice to replace 

LMR systems, it must either provide coverage 

everywhere or provide an off-network capability 

that would allow units to communicate directly 

without infrastructure.

The primary application for FirstNet is data 

transmission and Internet access. FirstNet could 

replace commercially provided data access needed 

for mobile computing used in CAD systems. 

Another application might be the data connectivity 

needed for fire station alerting. 

Possible Fire Service Uses

•	 Data connectivity for mobile computing/CAD.

•	 Hot spot for vehicles.

•	 Electronic patient care reporting.

•	 Application based.

– CAD.

- Hand-held dispatch.

- Accountability and location.

- Monitoring.

– EMS.

- Protocols.

- Drug doses.

- Pharmacological ID.

– Fire.

- Accountability and location of 

personnel.

- Reference material (Emergency 

Response Guidebook, SOPs).

- Extrication (where to cut vehicles).

When smartphones entered the market, the 

number of applications was small when compared 

to present. Like the explosion of applications in the 

private sector, a similar explosion will occur when 

public safety embraces this technology platform 

(Figure 10.5).
Voice Radio Communications Guide 88 for the Fire Service

Figure 10.5. Public Safety Communications Evolution

Public Safety Communications Evolution, May 2014, Department of Homeland Security, SAFECOM

Long term, it is envisioned that FirstNet will provide 

a technology convergence in the future. This 

concept would merge current data transport and 

LMR functions into the FirstNet technology platform 

as depicted in Figure 10.5. The convergence of 

technology is possible, but the fire service will 

need to validate and verify that the systems being 

proposed provide the capabilities needed to operate 

in the firefighting environment. We also need to 

require capabilities that provide the safety margins 

required to operate safely on the fireground. 

Ruggedized devices must also be available to 

withstand the rigors of the firefighting environment.

Summary — FirstNet

Signed into law on Feb. 22, 2012, the Middle Class 

Tax Relief and Job Creation Act created FirstNet. 

The law gives FirstNet the mission to build, operate 

and maintain the first high-speed, nationwide 

wireless broadband network dedicated to public 

safety. FirstNet was allocated 20 MHz of frequency 

spectrum in the 700 MHz band to manage for 

deployment of the Radio Access Network that is 

part of the FirstNet system.

FirstNet in the future may provide a single 

interoperable platform for emergency and daily 

public safety communications. The FirstNet 

network will fulfill a fundamental data transport 

need of the public safety community as well as 

the last remaining recommendation of the 9/11 

Commission. 

FirstNet is a data system being developed to meet 

the needs of first responders. It is envisioned as a 

4G LTE system for public safety designed to be:

•	 Competitively priced.

•	 Highly survivable and accessible. 

•	 Secure.

•	 Public safety focused. Provide public safety 

functionalities. 

•	 Mission Critical Voice: Off-network 

communications capability is mandatory.

FirstNet has stated that Mission Critical Voice, 

which is most important to the fire service, 

will be one of the last elements to be brought 

on line.
Section 10 | FirstNet 89

FirstNet is being designed to provide data access 

for public safety in times of emergency anywhere 

in the U.S. or U.S. territories. In recent history, 

the commercial systems have failed to provide 

connectivity when overwhelmed by spikes in usage 

from the general public.

FirstNet is being designed to survive extreme 

weather and seismic events. Public safety radio 

systems are expected to be operable when these 

events happen to maintain the ability to respond 

to the needs of the public. FirstNet is also being 

designed with security features that will meet 

the needs of the fire service and more stringent 

requirements of law enforcement.

The primary application for FirstNet is data 

transmission and Internet access. FirstNet could 

replace commercially provided data access needed 

for mobile computing used in CAD systems.

Long term, it is envisioned that FirstNet will 

provide a technology convergence in the future. 

This concept would merge current data transport 

and LMR functions into the FirstNet technology 

platform. Maintaining current LMR systems is 

necessary until FirstNet technology is deployed, 

tested, and proven reliable in the fire service 

environment and equivalent coverage needed by 

the fire service is attained. As of the development 

of this report, FirstNet has not yet made decisions 

on the actual design of either the broadband 

network or the costs public safety agencies will 

incur for its use.
Voice Radio Communications Guide 90 for the Fire Service

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Glossary 91

Glossary

Analog FM Radio: operates by causing the transmitting frequency of the radio to change directly with the 

microphone audio. The transmitter frequency variations are proportional to the amplitude of the input audio.

Association of Public Safety Communications Officers (APCO): serves the needs of public safety 

communications practitioners worldwide and the welfare of the general public as a whole by providing 

complete expertise, professional development, technical assistance, advocacy and outreach.

Atmospheric Ducting: a horizontal layer in the lower atmosphere in which the vertical refractive index 

gradients are such that radio signals are guided or ducted and tend to follow the curvature of the Earth.

Base Station Radio: located at fixed locations and usually powered by AC utility power.

Bidirectional Amplifier (BDA): used to extend radio coverage within structures to the outside of structures. 

Channel Bandwidth: the amount of radio spectrum used by the signal transmitted by a radio.

Continuous Tone-Coded Squelch System (CTCSS): mixes a subaudible tone with the audio from the 

microphone and transmits the resulting signal. When a radio receives a signal with tone-coded squelch, 

the CTCSS decoder attempts to match the tone present in the received signal with the desired tone. If the 

correct tone is present, the receiver is unsquelched and audio is routed to the speaker.

Decibel: a logarithmic unit used to express the ratio between two values of a physical quantity, often 

power or intensity.

Directional (Yagi) Antenna: an antenna that radiates or receives greater power in one direction allowing 

for increased performance and reduced interference from unwanted sources.

Direct Radio System: When the signal is received from the radio initially transmitting the signal, the 

communication is direct. (That is, there is no intervening radio or system.) 

Downtilt Antenna: directional antenna tilted to increase energy immediately below the antenna while 

reducing the maximum distance the signal will travel.

Dynamic Regrouping: allows an authorized system administrator to assign a radio or radios to a specific 

talkgroup remotely.

Emergency Alarm: When a user presses the emergency button on the portable, an emergency message is 

sent to any dispatchers using radio consoles.

Emergency Call: a call that is initiated by an “emergency alarm” activation. The “emergency call” is a 

high-priority voice transmission in the trunked system. The emergency call elevates the talkgroup to a high 

priority to ensure communications with the initiator of the call. 

Federal Communications Commission (FCC): a federal governmental board charged with regulating 

broadcasting and interstate communication by wire, radio and television.

Feedback: when radios operating in close proximity receive the transmitted signals from the receiving 

radios nearby. This creates a loop effect and introduces unwanted interference in the communications 

system. This is very common when operating on direct/simplex channels when the transmit and receive 

frequency is the same.
Voice Radio Communications Guide 92 for the Fire Service

First Responder Network Authority (FirstNet): an independent federal government authority tasked with 

cost-effectively creating a nationwide broadband data network and providing wireless services to public 

safety agencies across the country. FirstNet is an independent authority within the U.S. Department of 

Commerce’s NTIA.

Fixed-Site Antenna: antennas mounted on towers or buildings to provide the dispatch to or repeater 

coverage throughout the service area.

Frequency Coordination: a technical and regulatory process that is intended to remove or mitigate RF 

interference between different radio systems that use the same operational frequency.

Half-Duplex Communication: uses two RFs for communication. The transmitting radio transmits on 

Frequency 1, and that signal is received by the repeater. The repeater then repeats the transmission on 

Frequency 2, and this signal is received by the receiving radio.

IAFF Fire Ground Survival (FGS) Program: The purpose of the FGS program is to ensure that training for 

mayday prevention and mayday operations are consistent between all firefighters, COs and chief officers.

Institute of Electrical and Electronics Engineers (IEEE): promotes the engineering process of creating, 

developing, integrating, sharing and applying knowledge about electro- and information technologies.

Interference: unwanted RF signals disrupt the use of your radio. 

Intermodulation: frequency variation of two or more electromagnetic waves transmitted simultaneously 

through a nonlinear electronic system.

International Electrotechnical Commission (IEC) Standards Ingress Protection (IP) Codes: IP codes are 

international standards that test for IP into an electrical enclosure. 

International Municipal Signal Association (IMSA): designated as the frequency coordinator for all 

public safety agencies.

Interoperability: the ability of public safety responders to share information via voice and data 

communications systems on demand, in real time, when needed, and as authorized.

Land Mobile Radio (LMR): wireless communications system intended for use by users in vehicles 

(mobiles) or on foot (portables).

Military Standard 810 (MIL-STD): a standard for reliability and ruggedness, developed by the military, to 

provide an environmental test protocol that would prove qualified equipment would survive in the field. 

Mobile Radio: Mobile radios are designed to be mounted in vehicles and get their power from the 

vehicles’ electrical system. Generally, these radios have better antennas, receivers and provide higher power 

when transmitting from a vehicle.

Modulation: Modulation is the process of varying a higher frequency carrier wave to transmit information.

Multigroup Call: a call that transmits to two or more talkgroups simultaneously.

Narrowbanding: an effort to ensure more efficient use of the VHF and UHF spectrum by requiring all 

VHF and UHF public safety and Industrial/Business LMR systems to migrate to at least 12.5 kHz efficiency 

technology by Jan. 1, 2013.

National Association of State Telecommunications Directors (NASTD): a member-driven organization 

whose purpose is to advance and promote the effective use of information technology and services to 

improve the operation of state government.
Glossary 93

National Fire Protection Association (NFPA): a U.S. trade association, albeit with some international 

members, that creates and maintains private, copyrighted, standards and codes for usage and adoption by 

local governments.

National Institute of Standards and Technology (NIST): the federal technology agency that works with 

industry to develop and apply technology, measurements and standards.

National Public Safety Telecommunications Council (NPSTC): a volunteer federation of 15 public safety 

organizations, whose mission is to improve public safety communications and interoperability through 

collaborative leadership. NPSTC’s members are the organizations representing fire, EMS, law enforcement, 

transportation, and other telecommunications organizations (http://www.npstc.org/).

National Telecommunications and Information Administration (NTIA): executive branch agency that is 

principally responsible by law for advising the president on telecommunications and information policies. 

NTIA is responsible for federal frequency coordination.

NFPA 1221: Standard for the Installation, Maintenance, and Use of Emergency Services Communications Systems.

NFPA 1561: Standard on Emergency Services Incident Management System and Command Safety.

NFPA 1802: Standard on Personal Portable (Hand-Held) Two-Way Radio Communications Devices for Use by Emergency Services 

Personnel in the Hazard Zone.

NIST Technical Note 1477: Testing of Portable Radios in a Firefighting Environment.

NIST Technical Note 1850: Performance of Portable Radios Exposed to Elevated Temperatures.

Office of Emergency Communications (OEC): supports and promotes communications used by 

emergency responders and government officials to keep America safe, secure and resilient. The office leads 

the nation’s operable and interoperable public safety and national security and emergency preparedness 

communications efforts.

Omnidirectional Antenna: a class of antenna that radiates radio wave power uniformly in all directions 

in one plane.

Over the Air Programming (OTAP): allows system administrators to program radios over the air.

Over the Air Rekeying (OTAR): allows system administrators to rekey encryption codes over the air.

Personal Alert Safety System (PASS): monitors an emergency responder’s motion and automatically emits 

an audible signal to summon aid in the event that the user becomes incapacitated or needs assistance.

Portable Radio: hand-held radios powered by rechargeable, replaceable battery packs.

Private Call: allows one radio to call another radio and to carry on a conversation without any other radios 

hearing the conversation.

Project 25 (P25): a suite of standards for digital radio communications for use by federal, state/province, 

and local public safety agencies in North America to enable them to communicate with other agencies and 

mutual-aid response teams in emergencies.

Radio Alerting: feature that allows radios to be alerted to notify the user of incoming traffic.

Radio Console Equipment: used by dispatchers to control base station radios and repeaters and allow the 

dispatcher to receive and transmit on one or more radios simultaneously. 
Voice Radio Communications Guide 94 for the Fire Service

Radio Frequency (RF): any frequency within the electromagnetic spectrum associated with radio 

wave propagation.

Radio Spectrum: the range of electromagnetic frequencies used in radio transmission, lying between 10 

kHz and 300,000 MHz.

Receiver Desensitization Interference/Receiver Overload: caused by nearby high-level transmitter 

signals that overload the initial parts of the radio’s signals.

Receiver Multi-Coupler: a device for connecting several receivers or transmitters to one antenna in such a 

way that the equipment impedances are properly matched to the antenna impedance.

Receiver Voters: compares the audio from all receivers and routes the audio from the receiver with the 

best audio quality to the dispatcher.

Remote Speaker Microphone (RSM): a corded radio accessory that has a speaker/microphone 

combination that can attach closer to the user’s mouth.

Repeated Radio System: the portable transmit frequency is received by the repeater and retransmitted on 

the portable receive frequency at a higher power to extend range or increase penetration.

Repeater Duplexer: a tuned electronic device that permits the use of the same antenna for transmitting 

and receiving.

Request for Proposal (RFP): a solicitation, often made through a bidding process, by an agency or 

company interested in procurement of a commodity, service or valuable asset to potential suppliers to 

submit business proposals.

SAFECOM: mission is to improve designated emergency response providers’ interjurisdictional and 

interdisciplinary emergency communications interoperability through collaboration with emergency 

responders across federal, state, local, tribal, and territorial governments, and international borders.

Selective Disabling: allows radios to be remotely disabled if lost or stolen.

Short Message Service (SMS): Since the radios are digital, many trunked systems support sending short 

messages across the network.

Simplex Communication: when one radio transmits and the other radio receives on the same RF channel. 

Simulcast Transmitter Systems: multiple transmitters simultaneously transmit on the same frequency to 

increase the coverage footprint or provide in-building penetration.

Simultaneous Transmissions: multiple users trying to talk at the same time causing communications 

interference.

Squelch Circuit: used to mute the output of the radio receiver when no desirable signal is present and 

unmute when a signal of the appropriate strength is present. 

Talk-Around System: a radio accessory that attaches to the SCBA facepiece, may offer multiple talk-around 

channels that allow users to talk with each other in the hazard zone.

Talkgroup: equivalent of a channel on a conventional system. In a trunked system, there may be 

more talkgroups than RF channels. The design is based on the probability that not all channels are 

required simultaneously.
Glossary 95

Telecommunications Industry Association (TIA): represents manufacturers and suppliers of global 

communications networks through standards development, policy and advocacy, business opportunities, 

market intelligence, and events and networking.

Telephone Interconnect: allows users to answer or make calls to telephone users from the radio. 

Terrain Blocking: materials such as metal and earth completely block radio waves due to their 

composition and density. Radio waves can travel through some materials such as glass or thin wood but 

the strength is reduced. 

Time Division Multiple Access (TDMA): a channel access method for trunked radio systems. It allows 

several users to share the same frequency channel by dividing the signal into the different time slots.

Transmitter Combiner: allows multiple transmitters to connect to a single antenna.

Trunked Radio Systems: trunking borrows technologic concepts from telephone systems to assign RFs to 

active calls, improving the spectrum efficiency.

Ultra High Frequency (UHF): designation for the range of RFs in the range between 300 MHz and 

3 gigahertz.

Vehicular Repeater: a repeater that is mounted in a vehicle and is often used to enhance system coverage. 

This can be to provide more range or in-building penetration.

Very High Frequency (VHF): designation for the range of RFs in the range between 30 MHz to 300 MHz.

Vocoder/Codec: the algorithm and electronic components that perform the function of converting analog 

voice to a digital data packet and also provide the decoding of the signal as well.

Voice Amplifier: a PPE accessory that attaches to the SCBA facepiece and amplifies the user’s voice.

Wavelength: the distance between the crests of an electromagnetic wave. Wavelength is a factor in 

determining antenna length.
Voice Radio Communications Guide 96 for the Fire Service

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Acronyms 97

Acronyms

AASHTO American Association of State Highway 

and Transportation Officials

AHJ authority having jurisdiction

ANSI American National Standards Institute

APCO Association of Public Safety 

Communications Officers

BDA bidirectional amplifier

BID Bidder Information Document

CAD computer-aided dispatch

CDMA code division multiple access

CFLs compact fluorescent lights

CFR Code of Federal Regulations

CG Channel GuardTM

cm centimeter

CO Company Officer

COML Communications Unit Leader

COMT Communications Technician

CTCSS Continuous Tone-Coded Squelch 

System

DAS Distributed Antenna System

dB decibel

DCS Digital-Coded Squelch

DHS U.S. Department of Homeland Security

DVSI Digital Voice System Inc.

EMS Emergency Medical Services

ERU Emergency Response Unit

ESMR Enhanced Specialized Mobile Radio

FCC Federal Communications Commission

FCCA Forestry Conservation Communications 

Association

FDMA frequency division multiple access

FEMA Federal Emergency Management 

Agency

FGS Fire Ground Survival

FirstNet First Responder Network Authority

FM frequency modulation

FPIC Federal Partnership for Interoperable 

Communications

FRG First Responders Group

gpm gallons per minute

GPS Global Positioning System

HIPAA Heath Insurance Portability and 

Accountability Act

HSGP Homeland Security Grant Program

Hz hertz

IAFC International Association of Fire Chiefs

IAFF International Association of Fire 

Fighters

I/B industrial/business (radio service pool)

IC Incident Commander

ICT information and communications 

technology

ID identification

IDLH immediately dangerous to life and 

health

IEC International Electrotechnical 

Commission

IEEE Institute of Electrical and Electronics 

Engineers

IFC International Fire Code

IFSTA International Fire Service Training 

Association

IMSA International Municipal Signal 

Association
Voice Radio Communications Guide 98 for the Fire Service

INCM Incident Communications Manager

IP Ingress Protection

kHz kilohertz

LCD liquid-crystal display

LED light-emitting diode

LMRs Land Mobile Radios

LODD line-of-duty death

LTE Long Term Evolution

MHZ megahertz

MIL-STD Military Standards

NASTD National Association of State 

Telecommunications Directors

NFPA National Fire Protection Association

NIFC National Interagency Fire Center

NIFOG National Interoperability Field 

Operations Guide

NIMS-ICS National Incident Management System 

Incident Command System

NIST National Institute of Standards and 

Technology

NOI Notice of Inquiry

NPRM Notice of Proposed Rulemaking

NPSBN National Public Safety Broadband 

Network

NPSPAC National Public Safety Planning 

Advisory Committee

NPSTC National Public Safety 

Telecommunications Council

NTIA National Telecommunications and 

Information Administration

ODP Office for Domestic Preparedness

OEC Office of Emergency Communications

OSM Office of Spectrum Management

OTAP over the air programming

OTAR over the air rekeying

PASS Personal Alert Safety System

PL Private LineTM

PPE personal protective equipment

PS public safety (radio service pool)

PSAC Public Safety Advisory Committee

PSHSB Public Safety and Homeland Security 

Bureau

PSST Public Safety Spectrum Trust

PSWAC Public Safety Wireless Advisory 

Committee

PTT push-to-talk

RADO Radio Operator

R&O Reports and Orders

RF radio frequency

RFI request for information

RFP request for proposal

RPC Regional Planning Committee

rpm revolutions per minute

RSMs remote speaker microphones

RVS receiver voter system

SCBA self-contained breathing apparatus

SCIPs Statewide Communications 

Interoperability Plans

SIEC State Interoperability Executive 

Committee

SMR Specialized Mobile Radio

SOPs standard operating procedures

SWIC Statewide Interoperability Coordinator

TA Transition Administrator

TDMA time division multiple access
Acronyms 99

TIA Telecommunications Industry 

Association

TICs thermal imaging cameras

UASI Urban Areas Security Initiative

UHF ultra high frequency

ULS Universal Licensing System

USDA U.S. Department of Agriculture

USFA U.S. Fire Administration

VHF very high frequency

VoLTE Voice over LTE

VR vehicular repeater

Wi-Fi wireless fidelity

WMD weapons of mass destruction