Photo by Gert Zoutendijk
By Jay English
The nationwide public safety broadband network (NPSBN) currently being developed by the First Responder Network Authority (FirstNet) represents a paradigm shift for emergency responders nationwide. The ability to send, receive and share data across networks and across the country is life-saving technology whose time has finally come. Through tragedy we have learned there is a great need for true interoperability that spans more than just voice communications. FirstNet will help to fill that need and bridge the gap between the data citizens can now make available and the data PSAPs and responders have available.
It is important to note that while FirstNet will bridge the need for an ubiquitous data network, the need for interoperable, mission critical voice communications still remains. Voice systems are the backbone of emergency communications and the lifeline that keeps responders safe and connected.
There have been some misconceptions about the capabilities of FirstNet both at its launch and for the long-term goals of the system. These misconceptions have led to confusion within public safety circles and between the public and private partners who are building the foundation for the system. APCO believes that FirstNet is a viable and much-needed system. As a result, APCO has been involved in defining and supporting the network’s goals and construct since early in the process. As noted in the FirstNet Statement of Requirements, created under the guidance of the National Public Safety Telecommunications Council (NPSTC) and the National Institute for Standards and Technology (NIST):
“A number of real-world issues will challenge the design and implementation of the NPSBN. Members of the public safety community, FirstNet and other interested parties should, from the outset, be prepared to manage their expectations related to this unprecedented undertaking. Implementation of the NPSBN will not happen overnight. Network implementation may well mirror network deployments by commercial operators. It is important to understand that no commercial network operator has ever turned on a nationwide network all at one time.
Potential users of the NPSBN must recognize that some users will have access to the network earlier than others. Equally, there is currently no user equipment ecosystem for band class 14 devices, the spectrum allocated to the NPSBN. Also, current discussions regarding mission critical voice over LTE networks will have to be addressed.”1
Issues to discuss include what will be required when voice eventually becomes part of the NPSBN, and how we will continue to provide quality voice networks while the necessary standards are written and equipment is developed to support use of the NPSBN for voice services. For a number of reasons—not the least of which is the lack of handsets capable of supporting mission critical voice requirements, or the lack of an approved standard for voice over LTE—voice services were not included in the base recommendations for launch requirements. Most or all of these features will come in the later stages of buildout.
There are a number of other important features and functions that were not included in the launch day requirements. Among those are direct-mode mission critical push-to-talk (PTT) voice and off-network direct communications for both voice and data. These are services currently provided by land mobile radio (LMR) networks and they will continue to be supported by those systems for some time to come.
Public safety practitioners and technologists alike recognize that for an extended time after FirstNet is deployed, and even after LTE is initially capable of supporting requirements for mission critical voice, there will continue to be legacy LMR systems in operation.
Again quoting the NPSTC Statement of Requirements:
“As the NPSBN and existing LMR systems evolve, there is a need to interface from the NPSBN LTE system to these legacy LMR systems to promote interoperable communications. This interface will be required to preserve interoperability, as some agencies may transition their voice operations onto the NPSBN, while adjoining agencies may be slower in their transition planning. During this transition, a standard specification for LMR system interconnection to the NPSBN system needs to be established. This specification would be similar to what is known in computer programming as an application program interface (API).”2
Mission Critical Standards
Understanding the need to create new and more efficient broadband data systems sooner rather than later, while still allowing for the development and integration of voice systems as technology and operation allow, a separate effort was undertaken to create a base guidelines document for PTT mission critical voice.
This NPSTC working group noted several important considerations. First and foremost, the group recognized that the NPSBN will be of great benefit to the public safety community. The group also emphasized that PTT mission critical voice services must include direct mode communications and must preserve existing network resiliency, redundancy and reliability:
“While the public safety community recognizes the benefits that the deployment of the NPSBN will provide, we also believe that the ability to communicate directly from device to device will continue to be an essential component of public safety wireless communications in the future.
Today, public safety utilizes LMR systems designed with multiple hardened sites and equipped with emergency power (backup batteries and generators) to provide uninterrupted electrical power in the event of commercial power failure. In addition, public safety networks require redundant backhaul connectivity to ensure that first responder communications networks remain viable under the most severe circumstances. However, even if the infrastructure implemented in the NPSBN is hardened to the same standards as today’s public safety communications systems, the need to communicate via direct mode will remain essential for public safety in cases where the network is not available. Even as the NPSBN becomes more fully integrated into public safety wireless communications, public safety users will always need the ability to communicate by voice directly with each other in the absence of an operable network.
While we share the vision of an integrated nationwide public safety broadband network supporting voice, video and data as outlined in the National Broadband Plan, it is imperative that we preserve existing public safety grade voice PTT features essential to public safety operations. We must educate and encourage international wireless standards bodies to include public safety requirements in the LTE standards. This will allow public safety to realize the benefits of global standardization, while enhancing interoperability, and to benefit from a reduction of wireless costs.”3
Preparing for the Future
It is clear to those involved in defining and developing the NPSBN that voice services will not be available at launch and that those services must include mission critical capabilities before they can be implemented for public safety use. The Statement of Requirements identifies this fact from the onset. Furthermore, it is essential that public safety agencies have modern voice communications systems that can support their operations both now and for the foreseeable future. Even as FirstNet systems and technology become capable of providing some level of non-mission critical voice and eventually mission critical voice services, there will be the need for legacy voice networks.
Public safety agencies and organizations around the country have both operational and financial interests in utilizing the new capabilities that FirstNet will offer while continuing to operate their current LMR systems. As discussed previously, responders require mission critical services and features not yet available with LTE systems. Additionally, current public safety LMR systems are designed for extensive and reliable coverage that is redundant and resilient. Only when FirstNet can offer all of these features will it make operational sense to consider a migration to voice on FirstNet.
Additionally, agencies have billions of dollars invested in their current LMR infrastructures. From VHF or UHF trunked radio systems to P25-compliant digital systems, agencies have installed, maintained and upgraded these life-saving networks to ensure that responders remain capable of communicating.
When asked about the need to balance FirstNet and LMR systems, Tad Stone, director of public safety for Seminole County, Fla., said, “We’ve invested a significant amount of money into improving our existing LMR infrastructure and are in the process of upgrading it to P25. We did so knowing that we would be relying on this radio system for voice communications for the next 20 years. While we are very excited at the prospect of FirstNet bringing data capabilities to our responders, we also understand the need for a resilient, redundant, advanced LMR system to continue to provide our people with mission critical voice capabilities.”
Whether it is a financial consideration, an operational consideration or the issue that hardware and standards still need to be developed to support it, the fact of the matter is the migration to voice over LTE on the NPSBN will be a gradual one. As with other emerging technologies in public safety, including next generation 9-1-1 (NG9-1-1), this change will improve our ability to gather information, share information, respond to incidents and save lives. As is also the case with these other technologies, this change is an evolution, not a revolution, and it will not take place overnight. Our responsibility in the public safety technology sector is to continuously evaluate available options, integrate those technologies we can use today into our current systems and plan for those technologies that are coming in a smart, systematic and logical way.
As we move forward in defining, designing and implementing these new technologies, we also need to ensure that we don’t lose sight of our common goals. Whether public or private, our job is to collectively ensure that our systems and our responders are there when needed. Perhaps one of the most important things that will come out of FirstNet is not just technology. Perhaps just as important is the public-private partnership that emphasizes the need to work together toward a common goal—to save lives. If we approach not only the deployment of FirstNet, but also the integration of existing LMR systems with FirstNet, from this perspective and encourage a logical, phased approach, we all win. More importantly, our responders and the citizens they all serve will win and lives will be saved as a result.
JAY ENGLISH is APCO International’s director of communications center and 9-1-1 services. He has served in public safety and emergency communications for more than 25 years. He also has a background in electronic warfare and intelligence with the U.S. Air Force and served as a cyber crimes investigator during his law enforcement career.
REFERENCES
1. NPSTC. Public safety broadband high-level launch requirements. Statement of Requirements for FirstNet Consideration. Dec. 7, 2012.
2. NPSTC. Public safety broadband high-level launch requirements. Statement of Requirements for FirstNet Consideration. Dec. 7, 2012.
3. NPSTC. Public safety broadband. Push-to-Talk over Long Term Evolution Requirements. July 18, 2013.