NIOSH Firefighter Radio Communications 

TriData Corporation 11 September 2003 

CHAPTER III: FIREFIGHTER COMMUNICATION ISSUES 

Communication problems commonly encountered by firefighters (and others) can be 

broadly divided into two categories. First are mechanical or technical issues related to 

unsuitable equipment, system design, inadequate system capacity (too much radio 

traffic), and building construction, among others. 

The second category includes human factors such as radio discipline, training, and 

tactical decisionmaking. These factors, while not technical issues themselves, adversely 

affect firefighter radio communications, especially when combined with technical and 

equipment issues. 

This chapter presents an overview of these communication issues as well as a review of 

communications issues that affect fire departments every day. 

Technical Issues 

Fire departments consistently have problems maintaining effective communications while 

operating in large structures, such as high-rise office buildings and apartments, and 

warehouses. Similar issues exist in structures with a large number of windows (or areas 

of glass) with reflective coatings. Communications from areas below grade (e.g., 

basements, parking garages, subway systems, tunnels) tend to be uneven. For the typical 

home, communications are generally not a problem. The technical issues associated with 

the physical structures themselves (building materials, height, etc.) are discussed further 

in Chapter IV. 

Below is a discussion of the technical issues that are commonly associated with fire 

department radio communication difficulties. 

EQUIPMENT

In general, the most common communication problem encountered by firefighters is the 

inability to effectively communicate while wearing self-contained breathing apparatus 

(SCBA). In addition, it is difficult to operate most portable radios while wearing full 

personal protective gear (PPE). Thick fire suppression gloves make it difficult to turn 

knobs or push buttons, and low-light and smoke conditions coupled with wearing an 

SCBA facepiece make it hard to see the LCD display on a radio (if so equipped). 

Another common problem is the equipment’s tolerance to hazardous environmental 

conditions, such as high heat, prolonged exposure to water, and rough handling. While 

radios are water resistant, not all models are waterproof. This is more of a problem with 

older radios, however, as newer models are more water resistant if not completely 

waterproof. 
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Many radio systems are highly dependent on computer technology. In the event such 

technology fails (e.g., the trunking software becomes inoperable), the entire radio system 

can be disabled.2

 To prevent complete failure of the radio communication system, most 

jurisdictions employ backup analog frequencies to maintain critical communications 

(e.g., dispatch and contact with units). Reliability and sustainability are key components 

of any sophisticated system. 

The usefulness of a portable radio is dependent on the life of its battery. Some older 

radios require batteries to be “conditioned” or otherwise use special chargers for optimal 

battery life. This requires users to be especially diligent about maintaining radios and 

their batteries, which can be challenging for departments already busy with emergency 

response and apparatus maintenance. 

SYSTEM DESIGN

Perhaps one of the most critical technical issues related to radio communications is the 

design of the system itself. Whether a department uses low band, high band, analog, or 

digital technology, an adequately funded, carefully thought out, strategically designed 

system (i.e., the number and placement of tower sites and repeaters) will perform better 

than one that was not carefully planned. 

The lack of frequencies available to public safety agencies has made it difficult for some 

jurisdictions to modernize their radio communications systems. Public safety departments 

are limited to VHF low band, VHF high band, UHF 450 MHz, and UHF 800 and 900 

MHz. Instead of transitioning to a completely new system, many jurisdictions are 

exploring the possibility of applying new technology to enhance their existing system’s 

capability with only a modest expenditure of fire department budget. 

There are common design problems for most systems. An inadequate number of tower 

sites and repeaters typically result in “dead spots” – areas where radio communications 

are difficult or impossible. Buildings and terrain, among other factors, can cause dead 

spots. Similarly, a system might be designed with too little signal output to reach all areas 

of the jurisdiction (in some areas, for example, the radio system output is limited due to 

proximity to an airport or the Canadian or Mexican borders). 

As discussed later in this chapter, fire departments cannot always separate dispatch and 

tactical operations channels. This is a critical function, as the combination of dispatch and 

incident operations can overwhelm a single radio channel, causing critical messages to go 

unheard. Some experts also argue that large-scale incidents (e.g., high-rise fires) should 

 

2

 In a trunked radio network or system, a large number of workgroups (or users) share fewer channels 

because the trunking equipment dynamically allocates an available channel when users key their radio. A 

computer manages the system. When a user (e.g., firefighter) has a message to transmit, the computer 

assigns an available trunk. “The advantage of this type of system is that it uses a group of available 

frequencies more efficiently by utilizing the capabilities of the computer to manage the radio traffic on each 

frequency. Thus, more radio traffic can be handled on the available frequencies, without causing congestion 

and interference.” [314] 
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use multiple tactical channels to separate key functions, such as fire attack, search, 

emergency medical services, command, etc. 

SYSTEM CAPACITY

In general, fire departments throughout the country are responding to a higher number of 

calls for service than ever before and call volume will continue to rise. The majority of 

these calls are for EMS, which is a national trend. While EMS calls do not typically 

require a tactical channel, the associated radio traffic (e.g., dispatch, response, ER 

consults) may add to the system traffic. A dramatic increase in call volume and increased 

frequency of use may cause the system to reach capacity. As a result, existing 

communications may lack the capacity to handle the associated rise in radio traffic. 

A large-scale event such as natural or other disaster (i.e., terrorist event) is also likely to 

dramatically increase system traffic. In such cases, multiple city agencies or departments 

are likely to be at the scene of the incident, each using its respective communication 

system, possibly causing the radio system to reach capacity. 

Trunked systems provide more capacity than conventional VHF and UHF radio systems 

because a computer assigns a frequency only while a firefighter is actively transmitting, 

and then automatically takes it back when the transmission ends so the signal is 

immediately available for another transmission. 

INTERIOR (STRUCTURE) COMMUNICATIONS

It is critical for firefighters to communicate with one another within a structure and with 

units operating outside the structure, regardless of the building construction. The inability 

to communicate from buildings, below grade, basements, garages, tunnels, etc., is a 

persistent problem in the fire service. 

The construction of a structure can contribute to communications problems. Residential 

buildings are typically constructed of wood and other materials easily penetrable by radio 

waves. Commercial structures, however, are typically built with large amounts of steel 

and concrete that, to varying degrees, act as barriers to radio frequency waves. In 

addition, some types of glass and other window materials used in commercial 

construction inhibit radio frequencies. This topic is discussed in depth in Chapter IV. 

High-rise structures, warehouses, and underground structures such as tunnels and 

basements pose their own challenges to radio communications. In addition to the 

construction materials used to build them, the height of such structures can interfere with 

line-of-sight (LOS) access to repeaters and radio towers. 

Following the September 11, 2001, terrorist attacks, the Fire Department of New York 

(FDNY) contracted with McKinsey and Company to review its response and 

preparedness for future events. Based on interviews with firefighters, McKinsey reported 

that communication failures occur on a regular basis when transmitting from the inside to 

outside or vice versa from a high-rise building, tunnel, or subway system. Of the over 
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2,000 high-rise buildings in New York City, the FDNY feels that only a fraction allow 

reliable communications. [51] 

After-incident reviews of the World Trade Center collapse indicate that inadequate 

communications prevented personnel from receiving critical information about the 

impending collapse of the Towers. The reason cited was that FDNY portable radios do 

not work well in high-rise buildings and the signals from the radios were rebroadcast by a 

repeater system. Therefore, when critical information was relayed, it was sporadic or not 

fully received. 

McKinsey and Company notes that the communication failures can be corrected by 

deploying repeating infrastructure that “receives, amplifies, and retransmits radio 

communication signals to improve coverage.” The report observed that portable 

repeaters “may help mitigate in-building communication difficulties, but do not provide 

full coverage for high-rises,” and suggests that stationary repeating infrastructure is 

preferred, especially if it is “designed, installed and maintained properly.” [51] 

With an estimated cost of $0.30–$0.60 per square foot of high-rise space, McKinsey and 

Company estimates that FDNY would have to spend upwards of $250 million to install 

permanent repeater systems to ensure radio communications in the city’s high-rise 

structures. In the case of tunnels, McKinsey recommends that FDNY participate in the 

Police Radio System, which is funded by the Metropolitan Transportation Authority. The 

Police Radio System uses UHF radios to maintain two-way voice communication. 

Particularly with the vulnerability of a limited security subway system to a terrorist 

attack, FDNY and other fire departments with subway systems in their districts should 

ensure that communication systems are fully operational in these structures. 

POOR RECEPTION

Inadequate radio reception is the result of many factors. Most notable among these 

factors are low power, interference, and the terrain-and-built environment. 

There is a direct relationship between RF power output and transmitting range. The 

higher the RF output, the greater the transmitting ranges, and vice versa. Portable radios 

have a low RF output and, therefore, have a short operating range. On average, the RF 

output of portable radio range from 1 to 7 watts. [314] In comparison, mobile radios 

typically have an RF power output 20–100 watts. [314] Because mobile radios are not 

portable, they cannot provide on-scene communications or be carried into a large 

structure. As a result, firefighters must carry low-powered portable radios, which may not 

work very well in large structures. 

Atmospheric interference is uncontrollable. This natural occurrence results from solar 

disturbances on the surface of the Sun. These solar disturbances, also known as “solar 

flares,” emit large volumes of electromagnetic radiation and highly energized particles, 

which can affect satellite and radio communications on Earth. The highly energized 

charged particles pass through the ionosphere traveling at the speed of light and can 

affect radio signals over the entire frequency spectrum. 
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Electronic interference is also common. Many public safety radio systems often suffer 

destructive interference from a variety of sources, including commercial 800-MHz 

trunking antenna sites (Nextel, for example), interference with other public safety radio 

systems (e.g., neighboring jurisdictions), or other electronic devices. 

The environment – both topographic factors and the built-in environment (e.g., high-rise 

buildings) – is yet another cause of poor reception and solutions exist to help correct 

these reception problems. In some areas, additional antenna sites have reduced (or 

eliminated) interference caused by environmental factors. 

INTEROPERABILITY

Radio communications interoperability allows various departments (e.g., fire, police, 

public works) to communicate with each other or another neighboring jurisdiction. The 

objective is for these departments to exchange information when necessary (e.g., mutualaid call, mass casualty incident, special event). 

Throughout the country, adjacent jurisdictions or even agencies in the same jurisdiction 

use different radio communication systems. For example, while one county may use 

high-band frequencies (154.115–159.21 MHz), its neighboring jurisdictions might use an 

800-MHz trunked system. Or, a city’s police department could use an 800-MHz trunked 

system while the fire department uses a high-band system. 

Interoperability is not only critical in the case of a major emergency incident or disaster, 

but also important for the everyday types of calls where two or more departments are 

involved. 

While a significant problem in fire service communications, interoperability is outside the 

scope of this report and is not addressed in detail. 

DIGITAL VS. ANALOG 

Modern communication systems are evolving from analog to digital technologies. Digital 

systems offer better performance over a broader range of conditions, much greater 

flexibility, and more efficiency than analog at a lower cost. As with most alternatives, 

tradeoffs must be considered. Rarely does one find that all the pluses are on one side and 

that is the case with analog and digital communications. 

Performance 

The human ear corrects errors in analog communications systems. It can decode a wide 

range of hissing, crackling, volume changes, and other variations. As the signal to noise 

ratio (SNR) degrades, there comes a point where the transmission cannot be understood. 

But with digital communications, other error-correcting methods must be used. Digital 

communications allows for error-correcting codes that provide clear transmission over a 

much wider range of SNR than analog. However, at some point as the SNR drops, it falls 

so low that the digital system can no longer correct errors. When this happens, the signal 
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quality varies from perfect to gone. So, while digital schemes are capable of error-free 

transmission while analog ones are not, it is not uncommon to find radio users who prefer 

to let their ear decide when the transmission is indecipherable rather than have the signal 

just go away. 

Flexibility 

Digital communication systems can transmit analog signals obtained by analog-to-digital 

conversion, plus information such as computer data. Any signal that can be sent by 

analog means can be sent digitally. But an analog system cannot send everything that a 

digital system can. Video can be sent by analog means (standard television), but better 

performance is obtained using digital (HDTV). In addition to the ability to transmit a 

wider variety of signals than analog systems, digital communications can be organized 

into area-wide communications systems such as computer networks. These digital 

networks can be local, wide area, or even global and provide efficient and flexible data 

transmission not remotely feasible using analog means. 

Security 

Digital communications can be encrypted to provide robust security while analog cannot 

be protected nearly as well. 

Efficiency 

With digital communications, signal structure can achieve a much more efficient 

communication system via digital compression techniques. Digital communications are 

efficient enough to send more information per user to allow more users to occupy a given 

number of radio spectrum or channels. In analog communication, the only parameters of 

interest are message bandwidth and amplitude. 

Consequently, with the increased speed of digital computers, the development of 

increasingly efficient digital communications algorithms, and the ability to interconnect 

computers to form a communications network, digital communication is now the choice 

for many situations. 

Human Factors 

Even with the most technologically advanced radio communication system, the success 

and failure of radio communications depend on the person who transmits the radio 

message as well as the one to whom the message is transmitted. For example, location of 

the microphone in relation to the mouth and SCBA when transmitting can be important 

with some radio systems. The clarity with which the transmitting person speaks, coupled 

with the volume of the transmission, will drive the audibility of the message at the 

receiving end. It is also incumbent on firefighters to know when to transmit over the radio 

and when not to transmit a message. 
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MESSAGE TRANSMISSION

Well thought-out, clear, and concise messages are important characteristics for 

firefighters to employ during their radio transmissions. On the fire scene, when 

firefighters are excited or are panicked, radio transmissions can be loud and uncontrolled. 

Messages of this nature are difficult to understand. Discipline requires firefighters to 

exercise discretion in messages transmitted over the radio. Noncritical messages increase 

the radio traffic and may prevent emergency messages, such as a Mayday event or 

impending building collapse, from being transmitted. 

Over the years, radio codes and other phonetic techniques have been developed to make 

communications understandable, both for the sake of clarity and to compensate for poor 

radio links. These include the widely known phonetic alphabet (Alpha, Bravo, ..., 

Yankee, Zulu). Such alphabets, used for spelling things out over voice links, are 

variously known as phonetic radio spelling telephone alphabets and analogy alphabets. In 

addition, codes are commonly used by police and other agencies to provide succinct 

communication. These may be “10:4” or other numeric based messages that in some 

cases describe a response or situation. In spite of these techniques, clear and 

understandable radio communication is still a common problem. Firefighters must learn 

any terminology used in their jurisdiction. 

To counter problems with distortion and inaudible radio communications while wearing 

SCBA, some equipment manufacturers have designed integrated microphone and speaker 

systems into SCBA. Depending on the manufacturer, some of these systems use a bone 

microphone worn by the firefighter or a microphone integrated into the SCBA facepiece. 

Speakers are often a modified headset that fits in the firefighter’s ear, under their SCBA 

face piece and other protective gear. Most include a large, easy to operate push-to-talk 

button for use while wearing firefighting gloves. These systems increase the clarity of 

radio transmissions, reduce the amount of feedback from radios being too close to one 

another, and increase the likelihood that the transmission will be heard and understood. 

DIFFICULTY OPERATING RADIOS

As mentioned previously, the use of full PPE and SCBA makes it difficult to use a 

portable radio effectively. While the push-to-talk button is generally easy to use with 

gloves, the knobs and other buttons can be much more difficult. To overcome this, some 

departments are programming their radios so that the first and last position on the channel 

selector will automatically direct the firefighter to a channel monitored by the dispatch 

center. In the event of an emergency, the firefighter can turn the dial all the way in either 

direction and reach someone to alert them of the emergency. 

INADEQUATE TRAINING

Though firefighters receive hundreds of hours of training on emergency response, radio 

communications do not typically receive the same amount of attention. As such, 

firefighters may not be aware of proper radio usage. Examples include how to use the 
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radio in general, how to use the radio while wearing SCBA, and how radio 

communications are affected by a Mayday event. 

FIRE SERVICE CULTURE

Firefighters are, by their nature, problem solvers and independent. It is difficult to 

convince firefighters that they need to call for help quickly in the event that they become 

lost, trapped, or incapacitated. Waiting to call for help delays rescue efforts. And when a 

firefighter’s Mayday calls are not initially heard, rescue efforts can be delayed even 

longer. 

Applicable Standards and Regulations 

Standards have been developed to address communications systems, but, by and large, 

such standards are mute on identifying the best system for fire service communications. 

Thus each jurisdiction has the challenge of designing and building a radio communication 

system that meets its current and anticipated future needs. 

NFPA 

The National Fire Protection Association (NFPA) is a national nonprofit organization that 

develops consensus based codes and standards for the fire service. The NFPA has 

developed NFPA Standard 1221, Standard for the Installation, Maintenance, and Use of 

Emergency Services Communications Systems, 2002 Edition. This standard does not 

make specific recommendations on the types of radio system or frequency ranges that 

should be used by fire departments for emergency incident communications. Rather, it 

addresses construction, layout, staffing, and emergency backup components of the 

communication center. 

The nineteenth edition of the NFPA’s Fire Protection Handbook references radio 

frequency selection, but only shows that fire departments use VHF low band, VHF high 

band, UHF 450 MHz, and UHF 800 MHz and 900 MHz. It does state that, “each band of 

frequencies has its advantages and disadvantages, and the selection of a particular band 

will depend on factors such as frequency availability, area to be covered, type of terrain, 

number of radio units required, frequencies used by bordering fire districts, mutual aid 

agreements, type of operation, and use of emergency medical radios.”[314] The 

handbook also describes Simplex, Two-Frequency Half Duplex, Two-Frequency Full 

Duplex, Two-Frequency Repeater Systems, Trunked Systems, Tone-Coded Squelch, and 

Radio Paging Systems, but does not take a stance or recommend one type of system or 

frequency over another. 

FCC 

The Federal Communications Commission (FCC) is an independent United States 

government agency, directly responsible to Congress. The FCC was established by the 

Communications Act of 1934 and is charged with regulating interstate and international 
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communications by radio, television, wire, satellite and cable. The FCC's jurisdiction 

covers the 50 states, the District of Columbia, and U.S. possessions. 

Recent FCC activity of interest to the firefighting community includes: 

• Permitted use of UWB devices in restricted bands and restricted transmit power. 

• Removal of 50 MHz of government frequency allocation from 4840–4990 GHz 

with reallocation to public safety use. This band permits broadband services in 

support of public safety. 

• Allocation of 764–776 MHz and 794–806 MHz for public safety use. 

• Development and promotion of broadband services to compete with local 

broadband service from cable and telephone companies. As part of this effort, the 

FCC strongly supports development of Access PLC, which uses the medium 

voltage power grid to deliver broadband service to homes and offices. 

PSWAC 

Congress empowered the Public Safety Wireless Advisory Committee (PSWAC) in June 

1995 to address issues relating to spectrum needs and uses for the public safety 

community. The PSWAC identified an immediate need for 2.5 MHz more of spectrum, 

and a longer term need for an additional 25 MHz of spectrum for public safety use. 

PSWAC found that 70 MHz more of spectrum must be allocated if the public safety 

agencies and emergency responders were to use modern technologies, many of which 

require additional spectrum. 

Experiences From the Field 

This section summarizes the communications problems — mechanical and technical 

issues, as well as human factors — that are commonly encountered by jurisdictions 

throughout the country and the solutions implemented to mitigate them. Below are 

highlights of the actual communications problems experienced by these jurisdictions; a 

more comprehensive writeup is found in Appendix B. 

The departments reviewed were mostly all-career fire departments, large and small, in 

mostly urban or suburban areas as the information on these departments was more readily 

available. A small group of volunteer departments and jurisdictions in rural areas was 

also reviewed. In some instances, urban fire departments also provide fire or EMS 

services to rural areas. 

In all, information from 24 fire departments is included in this report. Of these, 18 are allcareer fire departments, 5 are combination, and 1 is an all-volunteer fire department. 

Table 4 summarizes the departments reviewed. 

The jurisdictions ranged in population from a high of 3.7 million in Los Angeles to a low 

of 3,700 in Gettysburg, OH. The service land areas also varied widely (as does the 

physical characteristics — terrain and topography — of each area). Land area protected, 
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as measured in square miles, ranged from 15 square miles in Springfield, NJ to 8,000 

square miles in Clark County, NV. 

Communication and radio system priorities differed somewhat in urban and rural 

departments. In urban settings, fire departments contended with a larger variety of 

structures such as high-rise buildings, multilevel residential structures, basements, 

tunnels, and underground transportation systems (e.g., subways). The rural areas, 

typically residential in nature, had fewer large buildings and generally no underground 

transportation systems. 

TABLE 4: SUMMARY OF FIRE DEPARTMENTS REVIEWED

Jurisdiction 

Resident 

Population3

Land 

Coverage area 

(square miles) Land Area 

Fire 

Department 

Type 

Austin, TX 656,562 252 Urban Career 

Bellingham, WA 67,171 32 Urban/Suburban Career 

Boston, MA 589,141 48 Urban Career 

Boulder, CO Rural Fire 

Department 18,000 25 Suburban/Rural Combination 

Brighton, CO 20,905 17 Suburban/Rural Combination 

Charlotte, NC 540,828 242 Urban Career 

Chicago, IL 2,896,016 227 Urban Career 

Clark County, NV 1,375,675 8,000 Urban/Rural Combination 

Dallas, TX 1,188,580 385 Urban Career 

Detroit, MI 951,270 139 Urban Career 

Everett, WA 91,488 48 Urban/Suburban Career 

Fairfax County, VA 969,749 395 Urban/Suburban Combination 

Gettysburg, OH 3,700 60 Rural Volunteer 

Los Angeles, CA 3,694,820 469 Urban Career 

Milwaukee, WI 596,974 96 Urban Career 

Phoenix, AZ 1,321,045 475 Urban Career 

Pittsburgh, PA 334,563 56 Urban Career 

Portland, OR 529,121 134 Urban Career 

San Antonio, TX 1,144,646 412 Urban Career 

San Diego, CA 1,223,400 324 Urban Career 

San Francisco, CA 776,773 49 Urban Career 

Schaumburg, IL 75,386 19 Suburban Career 

Springfield, NJ 14,429 15 Suburban Combination 

Wichita, KS 344,284 136 Urban Career 

In addition, urban systems experienced higher service volumes and increased radio 

traffic. Urban areas had a higher propensity for radio congestion. Fire departments in 

urban areas were mostly career, sometimes supplemented with volunteers, whereas rural 

systems have more volunteer providers. 

 

3

 Data from U.S. Census 2000 is used for consistency and comparison. Data may not agree with that 

reported by the jurisdiction. 
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Topography and terrain in both urban and rural areas varied widely. Typically, rural 

systems covered larger land areas that are more spread out and not as densely populated. 

Natural elements such as mountains, hills, and other potential interfering terrain were 

present in both urban and rural systems, depending on the area. 

More often than not, the urban departments have the resources to provide a 

communications system with the necessary hardware that meets the needs of the area. 

The urban areas had a greater population and tax base. In many departments, the fire 

department operating budget comes directly from property taxes. Properties in urban 

areas generally have a higher assessed valuation than an equal property in a rural area, 

and therefore will raise more tax dollars. 

Table 5 summarizes radio communications issues commonly experienced by the fire 

departments reviewed for this study. 

TABLE 5: SUMMARY OF FIRE DEPARTMENT RADIO COMMUNICATION ISSUES

Topic Area Issue 

Physical environment • Canadian & Mexican borders 

• Topography and terrain Poor Reception 

Interference • Neighboring jurisdictions 

• Wireless communications 

High-rise and other structures • Poor communications 

Interior Communications Tunnels and underground 

structures • Poor communications 

Hazardous conditions • Water exposure 

• Visibility Unsuitable Equipment 

Personal protective equipment • Self-Contained Breathing 

Apparatus 

System Design Inadequate infrastructure 

• Lack of repeaters and tower 

sites 

• Lack of channels and 

frequencies 

System Capacity System capacity • Inadequate capacity 

Mutual aid • Cannot communicate 

Interoperability Other city departments • Cannot communicate 

POOR RECEPTION

International Border 

• Problems – Departments located on or near the Canadian and Mexican borders of 

the United States often experience problems with signal strength and interference. 

Along the Canadian border, some localities have limited frequency space because 

Canada is reclaiming some of the VHF frequencies and essentially narrowing the 
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available bandwidth. Localities located on the Mexican border are often plagued 

with interference from sources across the border. 

• Solutions –The cities of Bellingham and Everett, WA, which experience radio 

communications difficulties because of their proximity to the Canadian border, 

are upgrading to an 800-MHz radio system. San Diego, CA, which experienced 

interference because of its location on the Mexican border, upgraded to an 800-

MHz radio system in the early 1990s. 

Topography and Terrain 

• Problems – Hills, canyons, mountains, and forests can often cause interference 

and dead spots, and the shadowing from mountains also poses similar signal 

disturbances. 

• Solutions – The City of Los Angeles encompasses 470 square miles that include 

hills, canyons, and mountains. Its fire department often experiences coverage 

issues because of this diverse topography. To overcome these challenges, Los 

Angeles has worked carefully on the strategic design and placement of radio 

system infrastructure (such as towers and repeaters). The Boulder Rural Fire 

Department even uses “human repeaters” when necessary. The City of Portland, 

OR, located behind the West Hills and close to volcanoes Mount Hood and Mount 

Saint Helens, experiences similar dead spots and communications difficulties. To 

combat these obstacles, Portland constructed a large antenna above the West 

Hills. 

Neighboring Jurisdictions 

• Problems – The radio systems of neighboring jurisdictions sometimes cause 

interference for fire departments. This occurs when adjacent towns operate on 

similar frequencies, and can sometimes prevent one department from sending or 

receiving messages. One jurisdiction may be at a higher elevation than the other 

and have higher towers. 

• Solutions – The Springfield, NJ Fire Department has taken steps to solve their 

interference problems with local jurisdictions and discussions are underway to 

investigate the feasibility of trunking the current radio system. This may prove an 

effective alternative to upgrading; in Springfield, there are not enough frequencies 

available for the department to transition to an 800- or 900-MHz system. 

Gettysburg, a rural city in Ohio, would like to upgrade it current radio system too, 

but does not have the funds to do so. 
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Wireless Communications 

• Problems – Many jurisdictions experience problems with the Nextel cellular 

phone system. The Nextel system, which operates on the 800-MHz band, seems 

to be incompatible with the pre-existing radio communication systems also in the 

800-MHz band. 

• Solutions – Fairfax County, VA’s public safety system is experiencing system 

coverage degradation from Nextel (interference), and has proposed moving 

Nextel out of the 800-MHz band. The county has developed this plan as a means 

of avoiding reorganization or restructuring of its public safety radio system. 

Portland, OR, which experiences similar problems, had Nextel and the fire 

department swap frequencies to solve the problem. The fire department gave up a 

channel on the end of their radio spectrum for Nextel’s channel in the middle of 

the city’s band. 

Clark County, NV is awaiting final approval between the FCC and Nextel on a 

plan that addresses interference to public safety communications in the 800-MHz 

band. This plan is known as the Joint Commentor’s Consensus Plan. 

INTERIOR COMMUNICATIONS – LARGE STRUCTURES

High-Rise and Other Structures 

• Problems – One of the most significant problems facing firefighters inside a 

high-rise structure is the ability to communicate reliably among firefighters and 

with the command post. Portable radios often do not have the RF power output 

necessary to communicate through the barriers inside the structure and reach the 

outside. Many of the cities reviewed have problems communicating during highrise operations. 

• Solutions – Jurisdictions have managed this problem in different ways, depending 

on the specific nature of the communication challenge. Pittsburgh, which uses a 

centralized UHF communications system for all city services, encounters most of 

its problems in large and high-rise structures, especially sub-ground or tunnel 

areas. The city solves communications problems with a talk-around system that 

uses two-way radios for a 1⁄2-mile communications radius. 

Dallas, TX and San Diego, CA solve their high-rise and structural communication 

problems by relaying messages via “runners” through egress stairwells. For 

special events, such as the 2003 Super Bowl and events at the San Diego 

Convention Center, the San Diego Fire Department uses a Mobile COW (Cellular 

on Wheels), which acts as a mobile antenna to repeat communications outside a 

building. 
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In Charlotte, NC the fire department is testing a mobile repeater and has reported 

some success in overcoming communications difficulties during interior 

operations, where the department uses simplex mode—radio to radio—to 

communicate. A mobile repeater adds signal strength to the interior of the 

structure, allowing firefighters to better communicate. 

Schaumburg, IL has a new 800-MHz system with four antenna sites. Fire 

department officials have reported dramatically improved communications during 

structural firefighting events. Before the new system, the fire department 

experienced dead spots throughout the village and problems in high-rise 

structures, typically constructed of concrete and Lexan glass. Additionally, new 

building codes required installation of signal boosters during construction for 

certain types of buildings. 

Phoenix, AZ uses a conventional direct radio communication system in VHF. 

Two tower sites and diversity receivers comprise the primary infrastructure. The 

receivers allow the department to communicate without talk-around channels or 

runners. The diversity receiver operates like small radio towers and accepts the 

emitted radio signal on several antennas with a radius of 2 square miles. The 

department operates 24 VHF channels, and there are 36 diversity receivers per 

channel. This system works well in high-rise and other large structures. However, 

it does have its drawbacks. The two most common challenges are fade and 

feedback. 

Many new buildings in Boston, MA, Clark County, NV, and Fairfax County, VA 

are installing bi-directional amplifiers. Bi-directional amplifiers, commonly 

known as BDAs, are used for improving/correcting portable radio 

communications to, from, and within large structures. These BDAs let fire 

departments operate their fire department channels within a building. 

Tunnels and Underground Structures 

• Problems – Road tunnels, often constructed with massive amounts of concrete 

and steel, create a manmade barrier to radio communications and pose a serious 

threat to firefighters. Other underground structures yield similar problems. 

• Solutions – The City of Boston is attempting to preempt communications 

difficulties while it constructs a major underground expressway. The city reported 

success with using a “leaky cable” device in its Ted Williams Tunnel, and plans 

to install the same device in the new expressway. This leaky cable is a “byproduct 

of conventional coaxial cable with small slits cut through its layers that allow RF 

signal to seep out in amounts strong enough to cover small areas of square 

footage.” [296] 
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TriData Corporation 25 September 2003 

UNSUITABLE EQUIPMENT

Water Exposure 

• Problems – Prolonged exposure to water can decrease the effectiveness of 

portable radios. If a radio system is antiquated, water exposure can cause serious 

equipment damage and endanger firefighters.

• Solutions – The straightforward solution to water exposure problems is to 

purchase new, waterproof equipment. The Milwaukee, WI Fire Department has 

reported no problems with its new portable radios; they are specially designed to 

be submerged in water without damage. 

Self-Contained Breathing Apparatus 

• Problems – Many firefighters struggle with the portable radio and the ease of 

using it in a zero-visibility environment while wearing bulky fire department 

gloves. 

• Solutions – The Schaumburg, IL Fire Department alleviates this problem by 

programming the extremes of the channel selector on the portable radio (selector 

turned all the way left or right) to the same, recognizable channel (usually 

dispatch) regardless of zone selection. So, if the firefighters operating in a zerovisibility environment accidentally change the radio from the tactical operations 

channel and cannot find it again, they can turn the selector all the way in either 

direction and still talk to a dispatcher in the event they need help. 

SYSTEM DESIGN

Lack of Repeaters and Tower Sites 

• Problems – Some of the fire departments reviewed experienced problems with 

radio communications due to a lack of essential infrastructure, such as repeaters 

and towers. In most cases, system infrastructures were insufficient. In other cases, 

poor system design and placement of infrastructure were the problem. 

• Solutions – San Francisco alleviated problems by switching from a 400-MHz 

radio system to an 800-MHz radio system 8 years ago. The newer system 

accommodates more working channels (16, with three controlled for dispatch and 

one for each of the 10 battalions) and interoperability. The department has also 

added more towers and repeaters and is currently upgrading the system with 

portable repeaters, as well as moving repeaters to higher elevations to prevent 

interference from high-rise buildings. 
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TriData Corporation 26 September 2003 

Similarly, the Wichita, KS Fire Department solved communication difficulties by 

switching to an 800-MHz trunked system 10 years ago. Each company officer has 

a portable radio. 

Chicago has solved communication problems by deploying a diverse multisimulcast radio system and 10 transmitter sites (per channel). The system has up 

to 32 receivers within any area it serves (12 square miles). Because of this, 

communications with dispatch via portable radios have highly improved. 

Los Angeles’s problems from the city’ size and diverse terrain and topography 

have been alleviated by incorporating backup repeater sites in these areas. The 

city has solved communication problems in subways and tunnels by wiring them 

with underground cables, which carry a signal for four or five of the fire 

department channels. 

Lack of Frequencies or Channels 

• Problems – Some fire departments have a limited number of tactical channels on 

their radio systems. These departments are vulnerable to communications 

problems when multiple incidents occur at the same time. 

• Solutions – Everett, WA accesses a single dispatch channel and a single tactical 

channel, which can complicate communications during fire incidents. To alleviate 

concerns, the department is upgrading to an 800-MHz system. 

SYSTEM CAPACITY

Many cities reported no concerns with system capacity, including Austin and San 

Antonio, Phoenix, Charlotte, Los Angeles, and Portland. These departments have 

standard operating procedures designed to shut down various parts of the system (e.g., the 

private line function and interconnect system of an 800-MHz radio system) to ensure no 

overcapacity. 

INTEROPERABILITY

• Problems – Often departments do not have the capabilities to communicate with 

other emergency departments (e.g., fire, police, public works) or with another 

neighboring jurisdiction using their own communications system. This is essential 

for exchanging information in mutual-aid calls, mass casualty incidents, or special 

events. 

• Solutions – Many departments are currently in the process of upgrading its 

communication systems to 800-MHz, specifically for interoperability purposes. 

Others have used alternate technologies or methods to improve or create 

interoperability. Following are a few examples. 
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TriData Corporation 27 September 2003 

A Boston Fire Department chief, acting as the incident commander, is collocated 

with an incident commander from another department. 

In Charlotte, NC all mutual-aid partners and chief-level officers in other 

departments are provided with radios. Similarly, departments in Dallas and San 

Antonio communicate with the police department through a “patch” system. 

Dispatch will patch police and fire together, and they can talk directly to one 

another. 

Chicago is developing a permanent solution to its interoperability problems, 

which include an inability to talk directly with law enforcement and EMS, as 

those departments operate on a different radio system. Because the fire 

department and EMS respond together on most incidents, the fire department has 

access to the EMS radio system (VHF) and the police and EMS radio system 

(UHF). Additionally, the department deploys a command vehicle, outfitted with a 

suite of radios that allow communication with all departments, to every major 

incident. 

In San Diego, the fire department uses a Motorola 800-MHz system, which has 

been in place for 11 years. The operations units also carry VHF portables because 

neighboring departments (recipients of mutual aid) use this system (e.g., 

California Department of Forestry). 

Communications Problems in Firefighter Fatalities 

Fire department communications have been cited as a contributing factor to the death or 

serious injury of numerous firefighters. The deaths have not been directly attributed to 

failures in radio communications. Rather when communications issues are cited, they are 

frequently problems in transmissions, standard operating procedures, or unsuitable 

equipment. Even when such issues strand a firefighter, casualties are generally associated 

with the fire, and few records are kept on the issues with portable radios. But review of 

the various departments and of fire literature revealed some instances where failed radio 

communications were at issue. 

In Syracuse, NY, four firefighters perished in 1978 while fighting a fire in a three-story, 

wood-frame apartment building. Reports attributed the deaths to failed radio 

communications. While failed radio transmissions contributed to past casualties, 

Syracuse was of particular note due to the number of staff who died. 

The trapped firefighters, confined on the third floor by a rapidly spreading fire, made 

several calls for help which went unheeded by dispatch, but which were heard by an 

observer who immediately reported the transmission to a fire officer on the scene. Thirtyseven minutes into the incident, the first of the fatalities was found. [123] 

Five firefighters were killed at a fire in Hackensack, NJ when the bowstring roof of a car 

dealership collapsed. Due to changing fire conditions, a battalion chief ordered all 

personnel to evacuate the structure. This order was never acknowledged nor repeated by 
NIOSH Firefighter Radio Communications Chapter III 

TriData Corporation 28 September 2003 

the dispatch center. The roof fell before the personnel could exit the structure. [335]

Hackensack had only one radio channel for both dispatch and tactical operations. Heavy 

traffic overwhelmed the inadequate tactical channel, and the firefighters’ transmissions 

for help were overridden by transmissions from dispatchers. 

A similar situation occurred in Brackenridge, PA after the floor of a commercial structure 

collapsed. Heavy radio traffic led the crew to switch from the primary incident channel to 

an alternate tactical channel — effectively cutting them off from the incident commander 

and the rest of the crews on the scene. The Brackenridge casualties resulted from radio 

operational issues; with only one channel for dispatch and tactical operations, the system 

was overloaded and dispatchers overrode transmissions from the fire ground. [339]

Unsuitable equipment and product design resulted in the deaths of two firefighters and 

the injury of a third at the Indianapolis Athletic Club during 1992. The injured firefighter, 

a captain, reportedly activated the emergency button on his portable radio and made 

several unsuccessful attempts to radio for help. While the push-to-talk button on the radio 

was easy to engage with a gloved hand, he had to remove his glove to use the emergency 

button, and seriously burned his hand. [337] Insufficient training might have played a 

role in the casualties. The department had switched to an 800-MHz system two weeks 

before the fire. This switch could have been responsible for the delay in acknowledging 

and processing a request for a second alarm. 

Two firefighters were killed and two more injured while fighting a townhouse fire in 

Washington, DC in 1999. The firefighters were caught in a flashover while attempting to 

suppress a basement fire. Department personnel were using frequencies that were 15 kHz 

apart, as recommended by NFPA. But in the past they had experienced problems with 

interference or bleed over between channels. This interference may have affected the 

ability of personnel operating on the scene to hear messages from the incident 

commander. [338]