U.S. flag

An official website of the United States government

Government Website

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Safely connect using HTTPS

Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


  1. Science and Technology Directorate
  2. News Room
  3. Arming Responders with Critical Interoperable Communications Capabilities

Arming Responders with Critical Interoperable Communications Capabilities

Release Date: April 12, 2021

It’s hard to believe that 2021 marks the 20th anniversary of the 9/11 attacks that shook our nation. For many, including all of us at the Department of Homeland Security (DHS) Science and Technology Directorate (S&T), it sometimes seems like just yesterday. We were borne from and remain driven by that infamous day.

One of the many lessons learned from 9/11 (highlighted in the 9/11 Commission Report): communication is key, particularly in the midst of chaos when multiple agencies and jurisdictions respond to a large-scale incident. We’ve made many strides in helping first responders address some of the communication struggles they faced then, and in the many days since. Today, as we kick off National Public Safety Telecommunicators Week, I wanted to take a moment to tell you about one of our latest efforts to evaluate and assess new technology in real-world environments—for and with our first responder colleagues—to maximize their interoperable emergency communications capabilities.

On April 6, S&T kicked off a 30-day FirstNet Push-to-Talk (PTT) field trial with 50 participants from the U.S. Coast Guard, Immigration and Customs Enforcement, U.S. Customs and Border Protection, the National Institute of Standards and Technology (NIST), Joint Wireless Program Management Office, FirstNet AT&T, and the Oakland, CA, Fire Department. During this period, participants will use provided handsets to experience a standard-compliant mission critical push-to-talk (MCPTT) application and test how well it performs.

The goal: ensure that current long-term evolution (LTE) and broadband systems, as well as the next generations of communication technology, don’t hinder responders’ ability to connect instantly and effectively. DHS operational components are already using PTT applications on broadband networks; however, several of the applications they’ve selected are not interoperable with other components, presenting cross-agency communications challenges. But leveraging standards-compliant PTT applications from carriers, including FirstNet, provides an opportunity to realize true interoperability on broadband voice applications. Standards-based communications equipment is one of the most valuable tools public safety has to combat interoperability challenges, helping ensure that proprietary, stove-piped solutions do not permeate the marketplace and result in jurisdictions unable to communicate with one another just because of the vendor they happen to select.  

The month-long trial includes an exercise with scenarios based in the San Francisco area to further test the MCPTT application, with remote participants monitoring on test handsets both in the Washington, DC, and El Paso, TX, regions. One emergency scenario will simulate a cargo inspection at the Port of Oakland with suspected narcotics while a fire breaks out at the port, and a second scenario involves a boat fire off the coast of San Francisco with a person of interest. The trial will also include support from the NIST Public Safety Communications Research program to conduct a voice quality assessment and study other critical parameters including latency.  

At the end of this event, S&T and its partners will evaluate feedback on FirstNet PTT usability and performance as a standardized approach for all DHS components. We’ll also conduct a second phase to assess PTT applications that provide off-network device-to-device communication and Land Mobile Radio-to-LTE interworking, as well as assessments with other network providers and operating platforms.  

S&T is committed to finding the best tools and means to ensure interoperable communications for DHS and our partners in public safety. Stay tuned, we’ll share the results of this MCPTT demo upon its conclusion. You can also visit our Office for Interoperability and Compatibility Technology Center to learn about additional efforts underway.

Finally, I want to close by extending S&T’s gratitude for all of those on the front lines working to continuously keep our lines of communication open. We honor you this week—know that we value your input and hope for your continued safety.

Last Updated: 04/12/2021
Was this page helpful?
This page was not helpful because the content