To many within the telecoms environment, emergency services have seemed like a world apart, operating independently on systems such as TETRA. However, there are signs that this may be changing as the unique demands of public safety services start to overlap with what commercial systems are able to deliver.
USA’s FirstNet runs on LTE and potentially will also use 5G, offering a fascinating look at how coordination and a willingness to innovate between public and private can work.
FirstNet is a service dedicated to public safety professionals – police, fire, ambulance, emergency management and more. In 2017, the FirstNet Authority (a government body) issued a contract to AT&T to build, maintain and upgrade a public safety network based upon LTE. It is not obligatory for any of the USA’s many local and regional public safety bodies to adopt FirstNet for their communications – as we will see, there are reasons for people to want to stick with their “Land Mobile” walkie-talkie services – but FirstNet has passed 2.3 million users and has over 200 applications in its dedicated public safety app store.
Can we get to a point in the future where one system can support the whole of our society? 6GWorld had an enlightening conversation with Harlin McEwen, long-time police chief and key mover behind the USA’s FirstNet initiative.
“I’m mainly interested in the area of 5G for public safety and public health,” McEwen explained. He is currently advocating for the FCC to use 4.9GHz for public safety 5G, integrated into the FirstNet network.
“We don’t have any dedicated 5G spectrum,” he explained, which is unlike the situation for LTE. While FirstNet runs mainly on commercial LTE spectrum, there is a unique 20MHz of “Band 14” spectrum in the 700MHz band set aside for public safety users which FirstNet can also tap into. While it’s not a huge amount of spectrum, it is significant in its effects.
A Matter of Priority
In any consideration of supporting public safety organisations, the need for a robust system in the face of an emergency is paramount.
Historically, the risk of commercial telecoms systems being overwhelmed has been very real – just ask anyone who has tried to make a phone call while leaving a busy music festival, for example. In the same way, emergencies tend to generate a good deal of cellular traffic. Without a way to solve the problem of services crashing due to too much demand, a separate network seems sensible.
The FirstNet system solves this in two ways. Firstly, FirstNet users are able to use public spectrum bands, but with “priority and pre-emption” over public users. One of the reasons why networks would crash under the weight of users in the past was because each user was getting equal priority and there was insufficient resource to go around.
Now, if AT&T resources are tight, first responders on the network get access and other users are kicked off. This leaves the same outcome for the general public but preserves a communications ability for those that really need it.
Secondly, that Band 14 spectrum builds upon the existing resources. As it is a low frequency it has a better range and ability to penetrate materials such as brick, concrete and glass. This supports the needs of first responders inside buildings as well as providing an extra quantity of spectrum on top of what has already been provided.
While McEwen is pleased about this, another crucial element to FirstNet is the way that its usage spreads beyond purely the emergency services, including on Band 14.
“Primary users include the police, fire service, ECC (Emergency Communications Centres, or 911) and so on. Extended primary users are people who support public safety. A good example is utilities; if the power is out, everything stops… They’re not public safety but they’re close to it. They all get acknowledgement as extended primary users which means they get priority and pre-emption, as long as the primary people don’t need it.”
This is a big step forward, enabling emergency services to communicate with each other, with “extended primaries” and – because it’s a cellular system – with non-FirstNet users with the same device. For McEwen, it just makes sense to enable “extended primaries” to access Band 14 in the normal course of things.
“20MHz is a lot of spectrum and it’s rare that all of it is ever used. The only time it would be saturated is a big event where a whole lot of public safety people would have to be sent in,” he explained.
If it comes to that, and there’s a risk of FirstNet struggling under the weight of its priority users, “We have a portal where we can manage, within our own people, who in police and who in fire has priority over everyone else. We have that capability as well, so that if everything is really saturated we can manage.”
Coverage and the Community
The second frequent concern raised by public bodies is the way that decisions about network coverage by commercial telcos is driven by economics. There are places that are simply unrewarding to deploy in but which will still experience emergencies, such as mountainous or forested regions. Driven purely by a commercial deployment model, those would not be covered.
“FirstNet is a gamechanger,” McEwen enthused. Because FirstNet is being deployed primarily for public safety users, the funding for part of the deployment was drawn from the LTE spectrum auctions, negating those commercial concerns. However, there are incremental benefits for end users.
“The law allows AT&T, as the contractor, to let the public access Band 14. If you’re a public user of AT&T and on their spectrum, if nothing else works it’ll allow you to use band 14 as long as you’re not pre-empted, which we feel is very rarely going to happen. So, AT&T is putting in Band 14 in some places where they don’t already have cellphone coverage.
“In a little town with 500 people up in hills of New Hampshire, I recently learned a man discovered he had AT&T coverage. He was amazed, because they had never had cell coverage. The reason is they put a Band 14 cell site in there for public safety. So now he has, for the first time, access to cellular coverage that he never would have had any other way because it’s not profitable for AT&T. They tell me they may eventually put in some extra public spectrum on that site.”
While this is perhaps a minor benefit on a national level, the pandemic has highlighted the difference in the ability to cope and react appropriately between people who have good connectivity and those who don’t, for whatever reason.
During October’s 6GSymposium, speakers including Michigan Congresswoman Lisa McClain emphasised the need for Beyond-5G services to reach everyone in order to reduce social and economic divides across the country.
This new kind of KPI is not exclusively a technology challenge but requires some different models for planning, deploying and using infrastructure, both terrestrial and aerial/ satellite, and that includes economic models different from traditional calculations. In this respect the FirstNet model may point a way for helping build out coverage where it is currently not economically viable.
“Across a lot of the country – and many people don’t know this – cellular coverage is becoming available in places that would never have been commercially viable, because of FirstNet and because of public safety. We always knew that was on the cards, but I don’t think the public or Congress quite realised that great outcome,” McEwen observed.
Applications Outside Emergencies
Interoperability across services, including with users not on FirstNet, has always been at the heart of the project.
McEwen is currently leading a project to develop a new push-to-talk broadband service called ES Chat that would interoperate with users who aren’t on FirstNet. “That includes mental health and public health leaders in the EMS [Emergency Medical Services] community,” he noted, discussing a recent trial at a hospital near him in upstate New York.
The results were unexpected. While ambulances certainly found it helpful, it solved a problem for inside the hospital too.
“They hand out ten cell phones to ten critical people every day – somebody in the emergency room, somebody at the switchboard, somebody in security – ten identified people who, if something major happens, they can call and coordinate with. But they have to dial them all individually. With ES Chat they can have a chat group and talk to all of them together.”
While it sounds surprising, this was a functionality which they had not had before, and which will support the coordination of emergency responses of all kinds inside the hospital. “They do have Land Mobile portable radios which are assigned to just a few people, but nothing like this and they can do it on their phones,” McEwen commented.
“From my perspective, in public health we’re not talking about 1,500 people in a hospital but a critical few who need coordinating.”
Life or Death
While FirstNet presents a great leap forward for usability and a combination of public safety and commercial networks, it is still not able to match the Land Mobile systems capabilities in some crucial regards, as McEwen concedes readily.
“If you’re trapped in a burning hotel and you can’t get a signal out to the cell tower, but you can reach the Fire Chief in the street, you can tell him where you are. That’s a life-saver. We don’t have that (in FirstNet),” he observed.
“The problem is that we still don’t have a reliable unit-to-unit capability. There are some options available – peer-to-peer kinds of things – but if you don’t have a network, basically, most of them don’t work. Whereas with our Land Mobile units we have five watts of power that can talk to one another if the infrastructure’s not there. That is a life-saver.”
There are a couple of reasons for this, but the sheer signal power that the Land Mobile systems use can blast a signal out effectively where regulations limiting cellular devices prevent a similar effect. “The power limitations are quite severe in cellular – you’re talking about two tenths of a watt of power.”
There are some steps being taken here, though, to reflect the demands of emergency responders.
“The FCC rules allow for higher power for public safety devices than for traditional cellphone devices, so right now we’re taking advantage of that with what we call High Power User Equipment [HPUE], which is allowed only on Band 14 and which allows us to transmit at 1.25 watts,” he said.
“At the moment it’s not practical for a handheld device, but it gives us the capability to reach from a device to a cell site much further away where the coverage isn’t that good. Secondly, once you’ve got that connectivity it allows us to establish a Wi-Fi bubble that can allow for communications where you wouldn’t have that with a simple 0.2-watt handheld device,” McEwen explained. This is being used effectively to equip ambulances in McEwen’s local area in upstate New York.
“The nearest trauma centre is either north 50 miles or south 35 miles. They’re often transporting trauma patients on a route where coverage is really spotty. So firstly when they transferred from Verizon to FirstNet they improved their service, and secondly they went to a HPUE modem in the ambulances… That gives them almost 100% coverage on the whole route where they only had 47% before. Tremendously different. In rural areas it’s a game-changer.”
While this is indeed a good step forward, it doesn’t resolve that life-or-death scenario for fire or police professionals. It is clear that the further development of ad-hoc, mesh or peer-to-peer networking in the coming generations of telecoms networks would add a very significant capability for public safety professionals.
Coordination and Data Management
US first responders are a large and diverse set of organisations. Within policing alone, there are over 17,000 federal, state and local law enforcement agencies, let alone public health, fire and emergency response. Surprisingly, a 911 call to the Emergency Communications Centre does not initiate the process of coordination between first responders.
“At the moment, management of the events is usually not done at the ECC, they just manage the communication. They pass messages, implement protocols and so on. You have an incident commander at the event and they manage the local people at the incident.”
However, as agencies increasingly digitise and bring analytical tools to bear on incidents there will be a greater need for more formal capabilities to share data and track resources.
For example, imagine a forest fire breaking out a few years from now – how easily can or should the incident commander (a fire chief in this example) use the forestry service’s drones to monitor the situation? What visibility is there into other emergency response resources available locally, both primary and extended primary? As the interface with the public, there is a case for using the ECC as a neutral host for gathering and coordinating information across agencies.
“Increasingly there’s going to be more and more of a role for the ECCs as we develop better, improved communications capabilities. So yes, that’s very important,” said McEwen. “We’re advocating for $5 billion to begin to build next-generation 911 in this country.”
However, it is early days as yet – unsurprisingly, coordinating action across such a diverse set of stakeholders with their own priorities is difficult. To give an example, McEwen noted that “little by little we’re developing text-to-911 capabilities across the country” as a useful way for people to contact emergency responders where they may not be comfortable speaking on the telephone.
As with the adoption of FirstNet itself, any increase in coordination will face challenges and take time to be adopted across the board, but McEwen is clear on the overall direction for future generations of emergency responders.
“Much more advanced and coordinated services; that needs to be the vision. How we do it – with what spectrum and under what rules – is all interwoven into it.”
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