Public Safety Advocate: FirstNet, Land Mobile Radio

Public safety has been using Land Mobile Radio (LMR) communications since the 1930s, broadband data is the new kid on the block, and FirstNet is even newer but has grown to adulthood in only three years. Some true believers in FirstNet even believe FirstNet will replace land mobile radio. The way I see it, both are needed and we will find ways to blend FirstNet and LMR to provide the best of both worlds for our first-responder community. 

Next-Generation 9-1-1 (NG911) is an important part of this strategy since it is the incoming pipe that will provide information to public-safety responders who use both FirstNet and LMR systems. In this Advocate, I will concentrate on the two communications technologies used in the field for routine communications as well as emergency communications. FirstNet and LMR together will play a vital role in smarter, safer communications for the public-safety community. 

There are differences between FirstNet and LMR and one reason FirstNet came to be was to solve some problems faced by public-safety LMR users. To understand why LMR operates on fragmented portions of radio spectrum, one must consider that when spectrum was first viewed as something to be used for communications, technologists thought they were limited to the lower portions of spectrum. Further, the FCC had to allocate spectrum to all the various organizations that were demanding it. As a result of these two circumstances, public safety received only small slices of spectrum. 

Over time, the upper limits of usable radio spectrum expanded, and each time a new swath of spectrum was “discovered” to be usable for communications, the FCC again doled out small slices to all who wanted it, including public safety. As a result, today’s public-safety LMR systems can be found in the 30-50, 150-174, 450-470, 700 and 800 MHz bands, the 470-512 MHz T-Band (that is supposed to be given back but hopefully Congress will repeal that part of the FirstNet law), and the 4.9-GHz public-safety WiFi-like band. 

Until recently, LMR radio equipment was not capable of operating on more than one slice of spectrum. This meant departments in the same city or county were often operating in different portions of spectrum and could not communicate with other city, county, or other agencies during mutual-aid events. This is the primary reason public safety suffered so many fatalities in the 9/11 attacks and why they were not able to provide better responses to the public during hurricanes Katrina and Sandy. These three events finally brought the lack of public-safety communications interoperability to the attention of the public even though the public-safety community had been facing these issues for more than thirty years prior to these events.

Today, LMR is very different from what it was even ten or fifteen years ago. Now we have more, different technologies. In the United States, there is Analog FM, P25 digital conventional, P25 Trunked, and Digital Mobile Radio, the baby brother of P25. In Europe and other parts of the world, there is yet another LMR technology known as Tetra. 

In many places, public safety has regionalized its communications systems to create better interoperability among and between agencies on a citywide, countywide, regionwide, or even statewide basis. Further, the National Public Safety Telecommunications Council (NPSTC) spent years pushing for and obtaining regionwide and nationwide interoperability radio channels. While these channels are spread out over the VHF (150-170), UHF (450-470), and 700 and 800-MHz bands, they are available to public safety, and for them to be usable by all, they are mandated to use Analog FM as the common mode of communications because Analog FM is the lowest common denominator.

While the LMR community is closer to being able to interoperate with other agencies and communities, some departments had to install multiple, expensive radios in each public-safety vehicle to overcome the lack of interoperability. With the advent of multi-band radios from Motorola, Harris, JVC Kenwood, and others, interoperability can now be provided using a single radio but at a stiff price point. Still, LMR does not deliver full nationwide interoperability for voice, text, data, and video services, thus the concept of FirstNet was developed and implemented.

FirstNet’s mandate is to provide a common radio system across the entire United States and its territories so any first responder or first-responder vehicle can be called in to assist and can communicate with all others involved in the multi-jurisdictional incident as well as their own Emergency Communications Center (ECC) back in their home district. LMR has not and will not be able to offer all this due to spectrum constraints and insufficient allocations in each of the six portions of the radio spectrum available to them.

Common Capabilities

1. LMR and FirstNet share some commonalities for communications. Both can be used for voice (push-to-talk) but we need to do a better job of bridging LMR and FirstNet for PTT to become universal between both technologies.

• Both require radio sites or cell sites to provide services in a given location.

• Both are available in fixed mobile devices as well as mobile handheld devices.

Different Capabilities

1. LMR offers robust off-network communications consisting of unit-to-unit and unit-to-multiple-units communications when users are either within network coverage and don’t want to burden the network with their localized radio traffic or outside the network’s coverage.

• LMR systems offer “graceful degradation,” meaning most LMR systems provide stepped fallback capabilities that are not available today in any broadband system including FirstNet.

• LMR systems make use of higher-power transmitters and external antennas, which means they provide better (but not perfect) inbuilding communications capabilities. (FirstNet is increasing its inbuilding coverage by using Distributed Antenna System (DAS) and other technologies but it will be awhile before it is able to offer the same level of inbuilding communications as LMR does today.)

• LMR devices offer user-selectable “channels” for listening and talking while FirstNet devices are fully automatic with no user intervention required.

• FirstNet cell sites are usually sectorized. This means the total network capacity is available in each sector. LMR systems usually make use of omni-directional antennas and only one person at a time can be talking on specific radio channel. FirstNet provides multiple “channels” within a broader amount of spectrum so multiple PTT, data, text, and video sessions can occur at the same time.

• LMR systems are limited to specific areas of coverage by the FCC and by the very nature of the systems. Today there are local, citywide, countywide, and statewide LMR systems while FirstNet is a single, nationwide network.

• Today, many LMR sites are closer to being public-safety grade than many FirstNet cell sites. However, FirstNet (Built with AT&T) has stated that the hardening its sites is a priority. 

• FirstNet and NG911 have IP back-ends. Except for a few P25 trunked systems, most LMR systems do not. The goal should be to make all LMR systems IP-complaint.

The next consideration is when first responders will choose to rely on their LMR voice systems and when FirstNet will provide better services that are required for a given incident. I believe the answer boils down to this:

An LMR radio with a speaker/microphone worn near the shoulder is easy to access and easy to use for voice communications. During an emergency today, the LMR system is better suited for emergency voice communications than FirstNet. Most if not all FirstNet devices have an emergency button that can summon assistance but the preferred method for calling for help when needed today is to simply press the push-to-talk button on the LMR speaker/microphone and talk. 

We are learning when and how FirstNet devices are being used. Once NG911 systems are in place in most areas, the type and amount of information sent into the field will increase and I believe FirstNet device usage will surge with the increased amount of information. The FirstNet vision is to be able to send audio, text, data, pictures, and videos to those responding to an incident. Many of these sources of information will only be available once NG911 systems are up and operational. 

In the meantime, Emergency Communications Centers (ECCs) can still send important information to field personnel including video from the scene, video from drones, and layouts and blueprints of buildings with locations of any hazardous materials as databases are brought online. Car-mounted and body-worn cameras will also provide information that can be of vital importance to first responders and ECC personnel.

According to first responders I have talked with over the past year or so, there appears to be a difference between how FirstNet devices are used beyond push-to-talk during normal patrol activities and during incidents. During routine patrols and after incidents, FirstNet capabilities enable field personnel to create reports, add pictures and video, and file them without having to return to the station. FirstNet devices are also being used for mapping, look-up, and similar functions. 

During a live incident, FirstNet device usage shifts to what I call “information resource terminals.” This shift occurs when those at an incident are more interested in viewing incoming data, situation updates, situational awareness, and other data that will assist them in handling the incident. Location of others can also be important and this can be displayed on FirstNet devices. At the moment, it appears that except perhaps for PTT, in the heat of a live incident the FirstNet device’s main function is to provide information rather than have responders create information. These usage patterns will change over time and, again, NG911 will be the prime driver for how FirstNet will be used during early stages of an incident. 

Moving Forward

Several non-technical issues will also shape how and when FirstNet and LMR devices are used by the public-safety community. There will be a shift in device usage as new recruits enter the public-safety workforce. These new recruits will have grown up with cell phones and then smartphones and these devices are playing a major role in their lives. Land mobile radio devices are foreign to them. Today, youngsters are helping seasoned veterans learn how to be more productive with their smart devices and veterans of an agency are showing newbies the ins and outs of LMR push-to-talk. There will also be shift in usage simply because those joining the public-safety community are well versed in the types of devices in service on FirstNet while LMR devices are totally foreign to them.

I believe it will be a very long time, if ever, before the 3GPP LTE standards body can develop off-network voice and data communications standards to meet the needs of the public-safety community. Off-network communications, vital to the public-safety community, must be sufficiently robust to provide ultra-reliable communications into buildings, sub-basements, and when there is no network coverage. Off-network communications is the final “graceful degradation” level of the LMR world and it must be reliable over terrain, in buildings, and when there is or is not network coverage.

My final point concerns devices. LMR devices put out much higher power than FirstNet devices, use external antennas that improve their performance, generally have replaceable batteries, and many handheld devices can use non-rechargeable, off-the-shelf standard AA batteries. When working wildland fires in California as a volunteer and/or communicator, one task assigned to us was to deliver cases of AA batteries to division chiefs in the field so fire fighters could replace their worn-out batteries without having to worry about access to battery chargers. 

For the most part, LTE devices have fixed internal batteries and internal antennas (exceptions include Sonim and Kyocera devices). I expect changes to FirstNet devices to include removable batteries and external antennas for public-safety-specific devices, and more FirstNet/LMR combination devices. It is easy to imagine a world as soon as ten years from now where first responders would carry combination devices with voice input, heads-up display, removable battery, and perhaps external antennas. 

Perhaps in that same period of time we will have communications devices like those featured in my favorite movie, “The President’s Analyst.” I have included a link to both clips we showed at one of our Wireless Dinners, which we hosted for more than twenty years. 

With the coexistence of FirstNet and LMR and now that FirstNet has created a viable market for first-responder devices, I fully expect to see the bright engineers who brought us into this century turn their attention to how to provide NG911, FirstNet (LTE and 5G), WiFi, and LMR in one device that can be used in the field. These devices would be designed so first responders would not even have to touch them to be on the “correct” channel, receiving the appropriate data at the appropriate time. Technology is no longer moving at the speed of sound; it appears to be moving at the speed of light.

Winding Down 

Two Advocates within a few days and now I am caught up and will return to Thursday morning releases. While activity continues in both the LMR and FirstNet worlds, we are anxiously awaiting a time when the U.S. Congress can return to business and start passing some of the bills public safety needs. These include repealing the T-Band giveback, funding NG911, pressuring the FCC to leave 4.9 GHz as it is today, reserving the 50 MHz of spectrum for public safety, and all the other items I listed in my first column of the year.

Meanwhile, I am looking forward to the rumored release of the newest member of the FirstNet push-to-talk club. I really want to find out more and if it will be a proprietary offering or if it will be more open. I sometimes think about how I would handle the problem of so many PTT systems on FirstNet. There are four qualified PTT vendors and multiple ways to integrate their FirstNet PTT services with those being used in the LMR community. Some say all we need to do is wait for the 3GPP to come up with interoperability standards. I disagree. 

It would make more sense to gather representatives from all the PTT vendors into a room and tell them they have ninety days to verify their PTT service interoperates with all other FirstNet-approved PTT services or they will be removed from the FirstNet-approved list. Several vendors have already figured out how to deliver this interoperability but they are stymied by another PTT vendor that says, “no I will not permit you to interoperate with my PTT solution.” This is not about who has the best PTT solution, rather, it is about the ability for each public-safety agency to select the PTT service it deems best for its purposes and still be able to communicate with an adjacent jurisdiction that may have chosen another PTT vendor.

While I am on this subject, I would also like to find a better way to integrate FirstNet and LMR push-to-talk systems. ISSI for P25 Trunked, DFSI for P25 Conventional, and Radio over IP (RoIP) for Analog is not a great set of solutions. It should be possible to simplify this and reduce the cost of LMR-to-FirstNet PTT integration at the same time.

I am bothered that many vendors are looking at how they can acquire more than their share of the business instead of asking, “What does the public-safety community really want and need?” and, “How can I provide that and win a chunk of the market?” It is human nature to want to be the top dog but there are times when it is more important to provide the best possible tools for the public-safety community at the best possible prices. 

Competition is good for everyone but when one vendor adds bells and whistles to the accepted standard to make their product “better,” meaning similar products from other vendors cannot match it, public safety is the loser. As NG911, FirstNet, and LMR systems are all expanding, I believe there is enough business for everyone who wants it, and as The FirstNet Authority has stated many times, that means open standards so multiple vendors can compete fairly for the business. FirstNet is the future of public-safety communications and it is coming quickly. LMR remains an important communications tool and NG911 will provide the final element of what public safety wants and needs—a smart system from citizens’ input to the conclusion of an incident.

Until next week…

Andrew M. Seybold
©Andrew Seybold, Inc. 2020