To Serve and Protect (and Connect): Next-Generation Antennas are Transforming Public Safety Vehicle Fleets into Mobile Communications Hubs

by Ted Hebron, Senior Product Manager, Laird Connectivity

When I was a youngster sitting in the backseat of the family car, I remember two things whenever a police car pulled up next to us at a stoplight. First, I remember quickly sitting up straight and trying to look respectable so the officer didn’t think I was up to no good. But I also remember something else: when the light turned green and the police cruiser pulled ahead, I was really interested in all the antennas poking out of the roof and the trunk. Our car just had the one—the standard radio antenna on the front passenger side so we could listen to oldies or the news. But the police car had so many more. Short ones alongside medium ones, and always that one long floppy antenna that bobbed up and down as the car drove along. I wondered what each of them were for. Little did I know I would end up designing antennas for a living and playing a part in the biggest evolution in public safety vehicle antennas since the first radios and antennas were installed in cruisers decades ago.

Wireless connectivity for vehicles of every type is taking a massive leap forward, and you don’t have to look very far to see it. Even family minivans are equipped with Wi-Fi hotspots, Bluetooth^® connectivity with smartphones, LTE connectivity for emergency services like OnStar^®, and more. That array of technologies keeps families connected while they are on a trip to the market or a daytrip to the beach, but the stakes are much higher for public safety vehicles like police cars, ambulances and fire trucks. Connectivity is a matter of life and death for those vehicles, for the first responders who use them, and for the public they serve, which is why there is a nationwide wave of upgrades being done to these vehicles to turn them into mobile communications hubs that support first responders with next-generation connectivity—to keep them safe and to keep us all safe.

Public safety vehicles have always been at the leading edge of vehicular connectivity, but police departments, sheriff departments, fire departments, EMT companies and other public safety organizations are currently moving forward with the largest, most ambitious collective upgrade of vehicular connectivity that has ever been undertaken. The driving force behind those upgrades is the launch of the FirstNet network, which I’m sure many readers of this magazine are familiar with. 

For those who have not read about FirstNet, it is a nationwide, dedicated cell network across the United States that is designed to keep first responders connected and coordinated during crises, even when the public cell network is overwhelmed. FirstNet was first envisioned after the 9/11 terrorist attacks, when connectivity challenges became apparent in places like New York City, where firefighters and police were competing for network access with regular citizens checking on the wellbeing of their loved ones. One of the key recommendations by the 9/11 Commission was that first responders and the U.S. public would be better served if a separate cell network were created to give public safety professionals dedicated connectivity served by a network that existed in parallel to what the public uses. 

For a variety of reasons, FirstNet was slow to come to fruition, but after nearly two decades since the tragedy that sparked the idea, this national telecommunications network has become a reality. The turning point was when AT&T was awarded the contract for building the FirstNet network nationally. AT&T moved ahead aggressively to build out the infrastructure in remarkable time and “flipped the switch” to activate the infrastructure roughly a year ago. Since then, thousands of state and local agencies involved in public safety have subscribed to the network so far, with thousands more in the works across all 50 states as well as U.S. territories. 

Those tens of thousands of public safety agencies have hundreds of thousands of vehicles in their fleets, and each of those cars, vans and trucks will need to have antenna upgrades in order to be FirstNet-ready. All public safety vehicles currently have connectivity, but it tends to be low frequency VHF-based and UHF-based systems rather than higher frequency LTE systems that are compatible with FirstNet. Vehicle fleets will need to be upgraded to have LTE connectivity as well, but LTE is not the only technology involved in these upgrades. 

In addition to FirstNet connectivity, public safety agencies are also thinking about a number of other wireless technologies necessary for these vehicles to function as mobile communications hubs. Wearable technologies like body cams and augmented reality visors will depend heavily on technologies like 5G and Bluetooth. The proliferation of onboard devices will require technologies like Wi-Fi. Location-based systems will require GPS connectivity. Plus, radio systems will continue to make VHF and UHF fundamental technologies for many vehicles. The bottom line is that there are multiple factors driving the need for a nationwide wave of upgrades to vehicle fleets. This article is intended to be a checklist of things that your companies and clients should keep in mind while helping first responder organizations with this migration toward next-gen connectivity.

These Upgrades are Not “Rip & Replace” –  For those of you who have played a role in vehicle fleet upgrades in the past, you know that they can sometimes be simple rip & replace tasks where the existing antenna solution is removed and the new one is plugged in with little fanfare. It would be great if the current wave of connectivity upgrades were that simple, but they are not. These are complex systems that involve not only FirstNet antennas but also multiple other wireless technologies, integrated together in multi-band antenna systems that typically require a sophisticated planning, installation and testing process to ensure proper functioning. It’s also important to remember that no two types of vehicles are alike in terms of how they function as RF environments. The shape of a vehicle impacts RF dynamics. So does the material of the surface the antenna system is attached to—such as whether it is metal or fiberglass. And a number of other factors influence what kind of solution makes the most sense, where it is installed on the vehicle, etc.  

Think About Scale as Early as Possible – One of the biggest missteps I believe organizations will make is thinking about how to upgrade individual vehicles without thinking ahead about how to replicate that process at scale for dozens or hundreds of vehicles. What might make practical sense for upgrading one ambulance, for example, might quickly reveal itself to be inefficient and expensive when multiplied by a fleet of 50 ambulances. Scalability should be a key driver for every decision in a wireless upgrade planning process because the impact of every decision gets magnified when vehicle upgrades are done at scale. For example, an antenna system might look like a good choice in terms of technical specs, but then turn out to require a difficult installation process that becomes a costly headache when done for a fleet of hundreds of police cruisers for an entire city’s police force. Choices that might add a negligible 20 extra minutes of installation time for a single vehicle will translate to hundreds of labor hours (and weeks of delay) when multiplied across an entire fleet. For every step in the planning process, your team should be asking: “What does this look like when we do this across the entire fleet?” That will help steer your team toward choices that ensure faster completion of the overall fleet upgrade and lower total cost of implementation.

Remember that FirstNet is More than Just LTE – LTE gets all of the attention because the FirstNet wireless network is based on the LTE standard, but it is critical to keep in mind that these vehicle upgrades need to support a lot more than simply FirstNet. Police patrol cars and officers’ wearable technology are a perfect example of this: LTE provides the overall link to the FirstNet wireless tower, but the officer’s patrol car is a complex multi-band RF environment. The patrol car must support connections for wearable Bluetooth technology, Wi-Fi for onboard computing systems, cell-based devices like smartphones and tablets, and a variety of other onboard wireless and wired sensors and systems. The key here is to begin talking as early as possible about the full range of wireless protocols that should be supported not only today but in the future, so these upgrades anticipate future applications.

Do Not Forget about Legacy Technologies – The FirstNet network is about moving forward on public safety communications, but many —if not most—first responder organizations may have older technologies and frequencies that they want to continue utilizing as part of their adoption of FirstNet. That means that new in-building and in-vehicle communication systems must coexist and work with legacy technologies on current P25 Phase I and II public safety communication protocols to ensure a streamlined transition to a cellular NPSBN system. Backward compatibility is a key discussion topic to customize FirstNet projects for each customer, and the legacy technologies they wish to retain may have a dramatic impact on the requirements and complexity of your project. 

Measure Twice Before You Drill – It’s one thing to drill a hole in a building’s interior wall to accommodate an interior antenna placement. It’s another thing to do that in a vehicle that needs to be out in four seasons of weather, where every hole in the exterior is a potential source of water intrusion that can ruin the entire vehicle’s electronic systems. Minimizing the number of holes drilled in a public safety vehicle is therefore critical, and there are two rules of thumb for doing that: 1) use multi-band/multi-port integrated antennas to consolidate wireless technologies in a single installation, and 2) perform RF testing to ensure that the new holes that are drilled are in the right places so that RF performance is maximized and RF interference is minimized.   

Think About the Profile – Antennas can be easily damaged, particularly when public safety vehicles are operating in areas with low-hanging tree limbs or vegetation that might do damage. The same dangers exist in urban environments when vehicles are in close quarters with other vehicles and other urban obstacles. Keeping a low profile is often critical to reducing the risk of damage, and many next-generation antenna solutions are designed with low profiles not simply for the aesthetics but also because of the practicality of avoiding damage from the environments in which they are used. 

Remember that Modeling is Not Enough. Test, Test, Test. – As the number of wireless technologies on vehicles increases, the RF environment becomes more and more complex, and the negative impacts on performance increase. Conducting RF modeling using software that predicts RF performance is a solid step, but it simply isn’t enough. To truly understand how a new antenna will perform and to understand how the existing antennas will perform with their new neighbor, you have to test it. Testing will reveal RF conflicts that are not anticipated by modeling software, and it will guide you toward proper antenna selection and installation locations that will optimize performance of all of the vehicle’s wireless systems. 

Create a Checklist for Your Gateway – Gateways and antennas for FirstNet implementation require multiple ports designed for a wide range of connectivity options to offer agencies more communication choices. However, many gateways may have a long list of ports and capabilities that appears to be complete, but should be verified even if there is a “FirstNet-ready” sticker on the box. Gateways and antennas must support 10/100/1000 Ethernet, RS-232 serial ports, DHCP server connectivity, USB, and general-purpose digital inputs. FirstNet gateways should also include support for a wide range of frequencies and bands, including LTE, WCDMA, EV-DO/CDMA, GSM/GPRS/EDGE, and LTE Band 14. And for rural areas without strong cellular coverage, a gateway with onboard support for satellite service via Ethernet is ideal. 

We’ve come a long way since the era of those police cruisers with the big, bobbing antennas on the rear hood that I saw as a kid. Connectivity is more important than ever for first responders, and the upgrades that are being made across the country to police cars, ambulances and fire vehicles will be critical to helping first responders stay connected while protecting all of us.

About the Author:

Ted Hebron is a Senior Product Manager for Laird Connectivity, which provides a full range of antenna solutions and wireless modules that simplify the process of using wireless technology. In this role at the company, Hebron leads development of Laird’s FirstNet-related solutions among other families of connectivity products. Hebron has 36 years of experience in RF design and antenna engineering utilizing a range of wireless technologies including cellular, radar, radio, television and low-observable connectivity. Has managed engineering teams in six Laird operations centers around the globe, and his work prior to Laird includes positions at Boeing, Harris Broadcast. He earned his BSEE degree from the University of Kansas.

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