Understanding FCC Frequency Bands for Public Safety and FirstNet

When police respond to a bank robbery, firefighters race into a burning building, or paramedics coordinate at a crash scene, every command, update, and plea for help travels invisibly through the air. Those life-or-death signals ride on FCC-assigned frequencies — invisible lifelines without which public safety communications capabilities would collapse.

The same is true for the video and data that police, fire, and EMS officers transmit and receive on their smartphones, tablets, and in-car computers. All of it is carried on FCC-allocated frequencies, as are the signals broadcast by radio and TV stations, and the cellular telephone/data traffic carried by AT&T and other companies.

Understanding why and how the FCC regulates the airwaves for first responder agencies and FirstNet (the dedicated, national public safety broadband wireless network created by Congress) underscores how vital this radio spectrum is for public safety. Without reliable access to communications, police, fire and EMS officers cannot effectively serve the citizens they are sworn to protect.

A Brief History of Public Safety Communications

Anyone who has ever watched a 1920s-era gangster movie has likely heard the words “Calling all cars” coming out of a radio in a vintage police car onscreen. This is because the earliest police communications system used one-way radios in their cars, with a central station broadcasting information over local AM stations. (The first such service was launched in 1921 by Detroit Police commissioner William Rutledge.)

In 1933, the Bayonne Police Department in New Jersey became the first to deploy regular two-way radios (aka Land Mobile Radios, or LMRs) in its patrol cars. Frequency Modulation (FM) was introduced in the late 1930s and early 1940s, handheld first responder radios arrived in the 1960s, followed by in-car laptop-like Mobile Data Terminals (MDTs) in the mid-1980s, and smartphones and tablets in the 2010s. Communication failures during 9/11 at the World Trade Center resulted in Congress creating FirstNet in 2012, to give all U.S. first responders access to a national wireless broadband network for their exclusive use, on a prioritized basis.

Why Frequency Bands Are Critical for Emergency Communications

To ensure that first responders have access to the radio spectrum they need to communicate, the FCC has allocated a number of radio bands to emergency communications over time. As these needs have grown more demanding over the years — because the amount of radio bandwidth needed to carry data and video is significantly more than is required to carry voice traffic — the Commission has allocated additional bandwidth to its “FCC bands/FCC emergency bands”, as some people call them.

FCC Frequencies for First Responders

Frequency Band	Assigned Purpose
VHF Low Band (30-50 MHz)	Narrowband Voice
VHF (148-174 MHz)	Land Mobile Radio (Voice)/Narrowband
UHF (450-470 MHz)	Land Mobile Radio (Voice)/Narrowband
UHF T-Band (470-512 MHz)	Allocated to public safety and in top 11 markets coexisting with TV channels 14-20
700 MHz (Band 14)	FirstNet Public Safety Broadband and Narrowband voice
800 MHz	Land Mobile Radio (Voice) Narrowband
4.9 GHz	Public Safety Broadband

“The FCC started out by assigning VHF Low Band and then migrated to allocating part of the VHF band (136-174 MHz) to public safety to carry LMR traffic,” said Stephen Devine. He is Chief Technology Officer with APCO International, the world’s largest and oldest public safety communications organization. “When that spectrum became saturated, the Commission allocated part of the UHF band (450-470 MHz) for public safety LMR,” Devine said. Additional Land Mobile Radio spectrum was allocated in part to public safety in the 470-512 MHz in the country’s Major Metropolitan Areas, coexisting with TV Channels 14-20. 800 MHz spectrum was introduced for LMR and introduced voice trunking to public safety. In 2002, the FCC allocated 50 MHz of spectrum from 4940-4990 MHz to public safety. “As police, fire, and EMS developed a need for data and video traffic carriage, the FCC responded by creating 20 MHz in the 700 MHz band (an aggregation of public safety wideband spectrum and commercial spectrum in the 700 MHz band, — known today as Band 14) and assigned it to the FirstNet Authority — for public safety broadband communications,” he said.

Recently, the FCC has changed its rules for the 4940-4990 MHz band to enhance access to the band and optimize its use by public safety. Like Band 14, 4940-4990 MHz rules also allow non-public safety use of the band to drive innovation, increase the bands use and allow public safety to leverage a commercial ecosystem of cost effective, high performing devices in its use of the band.

The reason the FCC has taken these steps is to ensure that police, fire, and EMS services can communicate effectively during manmade and natural disasters. This was particularly true after 9/11, a tragedy where lives were lost due to breakdowns in public safety communications.

The Importance of Band 14, Priority Usage, and FirstNet

Of all the FirstNet frequency bands used in the United States, it is Band 14 that matters the most to first responders. This is because Band 14 has been reserved for public safety’s priority usage at all times. (Non-first responders are allowed to use Band 14 by AT&T, which supports FirstNet under contract. However,resources dedicated to public safety coverage and throughput supersede commercial use are automatically preempted and/or blocked whenever first responder traffic increases.)

There’s a good reason for providing first responders with reserved radio spectrum for their smartphones and tablets. When a crisis hits — or just even a major public event like a concert or major league football game — cellular telephone networks become congested with too much traffic. This isn’t an issue for people sending selfies on their personal devices, but it can be disastrous for first responders trying to share data, images or video with Emergency Communication Centers and other responders from an accident scene, fire, or major incident. 

Making sure this doesn’t happen is why FirstNet exists. “Having radio frequencies that are prioritized for public safety use means that their calls can get through no matter what,” Devine said. “Meanwhile, providing this service using the same technology as consumer wireless broadband means that public safety benefits from the same advances in technology as well with devices such as smartphones and tablets. Because these advances are offered in millions of mass-market consumer devices, public safety gets to use them at a much lower per-unit cost than if they were buying lower-volume, higher-cost units only sold to police, fire, and EMS — as is still the case with LMR radios.”

Spectrum Basics 

There are two terms that often confuse people when it comes to public safety communications: narrowband and broadband.

Narrowband: small channels (12.5–25 kHz) good for voice only, some narrowband data.

Broadband: larger channels (25 kHz+) that can carry voice, data, video.

To understand the difference, consider this analogy: Narrowband is like a tiny pipe that can’t move much water. Broadband is like a big broad pipe that can accommodate any type of data, images, or video. It’s like a hose on a fire truck compared to a garden hose.

There are two more terms that matter: band congestion and spectrum interference. 

Band congestion occurs when too many signals are trying to use the same radio spectrum at the same time. It’s akin to too many people trying to push through a revolving door simultaneously.

Spectrum interference is the distortion and dropout that signals experience when too many are on the same frequency — like too many people shouting in a crowded room at once.

FirstNet’s 5G Expansion and the Future of Public Safety Radio

The world is moving to 5G, and FirstNet is no exception. Its operating body, the FirstNet Authority, is investing $6.3 billion of collected user fees to provide 5G services to its 7 million+ first responder users. This upgrade will ensure that U.S. police, fire, and EMS officers will be able to access the same level of fast service and sophisticated applications that are available to consumers. 

“We don’t want an average 14-year-old to have more capabilities on their smartphone than police, fire and EMS,” said Devine. “To keep people safe, public safety has to have access to priority service on FirstNet, to include 5G technologies and beyond. Fortunately, that’s exactly what FirstNet is working on now, while preserving 4G/LTE service to its customers to keep them connected. Keeping Americans safe comes down to robust, reliable mission critical public safety communications that everyone can count on.”

From the static-filled car radios of the 1920s to today’s FirstNet broadband network, public safety communications have come a long way. The FCC has realized that to provide for public safety they need to ensure dedicated public safety spectrum can access legacy voice networks AND commercial broadband networks. The FCC’s thoughtful allocation of spectrum and its acknowledgement of technology advancements occurring in the commercial marketplace ensures that first responders remain connected, no matter how crowded the airwaves become — because in an emergency, every second counts.

FAQ

What frequency bands has the FCC allocated for public safety use?

To keep Americans safe, the FCC has allocated parts of the VHF band (136-174 MHz), 

the UHF band (470-512 MHz), the 700 MHz band, and the 4.9 GHz band for public safety broadband communications.

What is Band 14 and how is it used for public safety communications?

Band 14 is a 20 MHZ slice of the 700 MHz band that is reserved for priority first responder voice, video and data over broadband wireless.

How are police, fire, and EMS radio frequencies assigned?

The FCC manages the assignment of VHF/UHF radio frequencies assigned to first responder agencies to prevent band congestion and interference. FCC Certified Public Safety Frequency Coordinators coordinate radio spectrum so it can be shared between public safety agencies. FirstNet has been assigned Band 14 by the FCC, which is managed on its behalf by AT&T to ensure priority service to public safety users. The 4.9 GHz band is being managed nationally for public safety users by FirstNet, under FCC authorization.