Public Safety Advocate: Off-Network Communications

Welcome to June! May is in the books and now we are looking forward to what June might have in store for us. Public-safety agencies around the United States and the world are facing trying times and difficult duty and still they respond to keep us safe. Wireless communications enable public safety to communicate, coordinate, and deploy assets to where they are needed. Today’s public-safety community has the greatest-ever communications with the best yet to come. I am waiting for the day Next-Generation 9-1-1 (NG911), FirstNet, Land Mobile Radio (LMR), WiFi, Bluetooth, and other technologies use the same IP back-end and communications are directed to the appropriate public-safety personnel to prepare our first responders to handle incidents when they are dispatched.

Off-Network Communications 

Call it off-network, talk-around, simplex, one-to-one, one-to-many, or peer-to-peer for IT folks, it is all the same. Regardless of how good a network or series of networks is, there are times when those in the field need to take their communications off the network(s) and down to a local level. Public-safety radio communications began with one-way from the stationhouse to the vehicle and then evolved in the 1930s to two-way radio base station-to-mobile and then mobile-to-mobile. After a number of technological advances, we now have multiple networks. Land mobile radio handles voice only (and some very low speed data) and FirstNet (Built with AT&T) and other broadband networks handle voice in the form of dial-up and Push-To-Talk (PTT) as well as text, data, video, and still pictures. Even so, there are times when public-safety personnel are out of network coverage, when some are in coverage and some are not, and when within network coverage but need to communicate on a more local basis.

Some public-safety agencies do not use off-network or use it rarely, but many agencies use off-network communications for every incident they respond to and many fire-service incident dispatches include a working off-network channel. Off-network is often preferred by swat teams, detectives, and other units that need to stay in contact with their group without taking up network resources. Another reason is to keep it local so fewer people with radio scanners or Internet rebroadcasting services can listen to an incident in progress. The issue of eavesdropping is non-existent with broadband networks so far, especially FirstNet since a great deal of time and effort has been spent to ensure FirstNet is a secure network.

One of the most compelling uses for off-network is to communicate in areas where the network cannot or does not penetrate. Having plenty of network signal standing in front of a building does not mean public-safety professionals will have network coverage as they enter the building, descend to a basement, or move deeper into the building. Today, both LMR and FirstNet are penetrating deeper into buildings than ever before and networks or landlords are installing in-building communications, especially in large buildings. However, wireless networks are not always available inside buildings, in sub-basements or underground parking garages, or in rural areas not covered by wireless networks. Off-network communications is a must-have for most or all of the public-safety community.

My Advocate last week discussing push-to-talk interoperability drew a number of positive comments as well as questions about off-network coverage and progress in this area. There has been some progress in off-network communications and if APCO and IWCE (Although now the web-site says it will be 100% online) are both held in August as planned, I expect to see a number of companies adding off-network communications capabilities by combining LMR and FirstNet devices. We have already seen how L3Harris and others have gone about building LMR and LTE into a single device. Others have dual-network LMR/broadband products and there will be more, at lower price points, especially for FirstNet and one segment of public-safety LMR spectrum, e.g., FirstNet/VHF, FirstNet/UHF, and FirstNet 700/800 devices. These dual-purpose radios sell for less than a single radio that covers all three LMR spectrum segments plus FirstNet. 

Some vendors are employing Bluetooth so an LTE device and an LMR device can be controlled by one or the other. Motorola LEX and APX handheld LMR radios are a good example of this type of “integration.” Sonim previously announced a “sled” for off-network communications but the first version is on 900 MHz and very low-powered unlicensed spectrum (XPand). I am not convinced Sonim’s website description is completely accurate as it reads: “Communicate with up to 100 co-workers within a 1-mile radius without cellular coverage.” Sonim claims it is using a 1-watt transmitter so perhaps it will cover up to a mile, but I am not sure this would meet the off-network criteria I set forth in a previous Advocate. Perhaps Sonim’s next sled should be designed to operate on VHF or UHF in a simplex-only mode. 

Battery life is the primary concern when combining devices or using the high power permitted on FirstNet Band 14 in a handheld. Most handheld LMR devices are designed to provide a typical shift-plus of power and have removable, replaceable batteries. Smartphone and tablet batteries last much longer than a shift unless they are being heavily used. (A few including the Sonim XP8 and Kyocera smartphone have removable batteries.) Adding high-power Band 14 ProSe (3GPPs off-network specification) will require a much heftier battery and an external antenna to attain the best possible distance and building penetration. I am not privy to what 3GPP has in store for ProSe, but as I have said before, as it exists today, ProSe is basically useless to the public-safety community. There is no way it could pass any of the tests I have determined necessary before public safety will trust an off-network device for daily use.

Future Devices

There is a need today and far into the future for robust off-network communications capable of multiple channels or groups since during major incidents some public-safety groups want and need their own “private” channel(s) to manage their portion of the mission. During a hostage incident, they might need one channel for swat, one for crowd control, another for hostage negotiations, and a few more. The greatest number of direct, off-network channels are needed during wildfires as the Incident Command adds layers of management and deployment. In some California fires where I provided volunteer communications support, all available VHF simplex channels were assigned resulting in sixty to seventy channels being used. 

I do not believe public safety would welcome a device with limited off-network communications capabilities without some reservations. What is needed is a single device that provides both on- and off-network capabilities. There is an ongoing conversation within the public-safety community about how many communications devices those in the field really need to carry. Some recent articles have made the case that FirstNet or LTE is the only device needed, but I have to assume those leaning in that direction do not use off-network or have not thought about how devices are used in the field on a day-to-day basis. Others favor a single dual-LMR/FirstNet LTE device. The last category is those who prefer two separate devices: an LMR device that has long been their lifeline and a smartphone so they can be better informed while in the field. 

Age and experience influence device choices. People who have been on the job for many years have been using LMR devices in their vehicles and handhelds since they joined. Their experience with smartphones and tablets usually started with a fixed notebook computer in their vehicle and a data connection over commercial broadband. When they started using cell phones and then smartphones and tablets in their personal lives, they often used their personal smartphones while on duty. Today, if their department is signed up on FirstNet, they carry both LMR devices and smartphones or tablets. 

The next, younger, group of first responders grew up with cell phones and transitioned to smartphones and tablets as they became available. I have been told by some within public safety that seasoned personnel are teaching newer, younger recruits how to use LMR while the younger first responders are teaching the old guard how to make better use of their smartphones and tablets. The next wave of people to join the ranks of the public-safety community will have grown up with smartphones and tablets being second nature to them. As these younger members move up the ladder, it will be interesting to see who will want single devices, multiple devices, or two different devices, which seems to be today’s preference. 

All this suggests there will be several waves of devices brought to market and put into use. We will learn a lot from these but I, for one, do not believe we will find overwhelming support for any one solution: a FirstNet-only device, a combined FirstNet/LMR device, or a two-device world for the foreseeable future. Vendors that take the time to understand the direction the public-safety community is heading will be best able to design its next-generation-or-later devices. On-duty public-safety professionals live in a very different world from civilians. Time is often critical, assistance is a priority, tracking who is doing what and where is imperative, and being able to dictate or write after-action reports are all activities that need to meet precise standards. 

When I worked for General Electric Mobile Radio (now L3Harris) in the mid-1970s, Cincinnati’s fire department wanted to provide every fire fighter with a “scene of the fire” radio communications system. The idea was for a handheld radio to be fitted into a pocket sewn onto the turn-out-gear, a bone-conduction microphone to be attached to the front middle of the helmet, and an over-the-ear speaker. Setcom was chosen to provide the headgear and sent a sample helmet with over-the-ear pieces covering both ears. The fire chief took one look and said no firefighter he knew would accept having both ears covered. After we worked with Setcom to modify the headgear for a single earpiece, the firefighters really liked it.

The covering-both-ears lesson has stuck with me over the years yet I saw a new speaker/microphone announced by a vendor that combined LMR and FirstNet audio into a single speaker/mic using two cords to connect to the devices. I think this is a non-starter. In order to listen to both radios, there must be a Bluetooth earpiece in both ears. I like the idea of two audios using Bluetooth, but not when it requires putting earbuds in both ears. The lesson here is that designing a product for the public-safety community without input from the community makes little sense. However, talking with one department or one seasoned expert is not enough because the wants and needs of the public-safety community change from area to area, region to region, and between law, fire, and EMS services. Taking the time and effort to ferret out how your product might be received means conferring with potential users, and as your product progresses, revisiting them to make sure you are on the right track. Above all else, remember that the public-safety community is a group of professionals who run toward danger and do not have time to mess around with complex technology. They want the products they need and they need them to work well. Finally, you only have one chance. If you mess it up, the public-safety community will remember it for many years.

Where Devices Are Headed 

We don’t know now, and we might not know even when we get there. In the meantime, some new devices will work well and be welcomed and some will collect dust on warehouse shelves. My vision of where we should be headed is described in an article for MissionCritical Communications: “If all these various types of communications are put together in a synergistic, IP-based system and field personnel carry devices that help them navigate to the specific network they need when they need it, public-safety communications will remain what it is today — a tool for public safety. Law enforcement, fire personnel, EMS, and other first and second responders can perform their tasks without having to think about which communications method is being used. The networks in concert will deliver the content to the appropriate people at the right time.”

I am suggesting a set of smart networks sending and receiving information to and from smart devices carried or worn by public-safety professionals and those in the field that do not require changing channels or even looking at the device. Perhaps a heads-up display would work, but I see the end-game as a set of networks and devices that include off-network one-to-one and one-to-many communications that are intelligent enough to provide the right communications to the right people at the right time. Anyone who believes we can do without off-network communications has not been in a sub-basement surrounded by fire knowing the only way to summon help is via off-network communications that are sufficiently robust so others will hear and respond. 

We have the communications tools, technology advances, and users who need what the wireless community provides. Now we need to put it all together so interoperability and on-network versus off-network are no longer issues. If we all work toward this goal it will be achievable sooner rather than later or never.

Winding Down

I hope some vendors will spend time on the issues I have outlined above which are, for the most part, common knowledge within the ranks of first responders. Thinking back to devices that might have changed the world of public-safety communications, I keep returning to a speaker/microphone developed by Motorola that never made it to market. This speaker/mic was developed to interface with the then-current Motorola handheld radio, but inside the speaker/mic housing there was a full-blown GSM (Cellular 1G) phone and there was a touch-tone pad on the back for dialing and controlling the phone. At the time, I thought this device would be a game changer. However, the cellular radio division of Motorola complained to upper management that a GSM phone was in its purview and a cellular phone could not be built and sold by the land mobile radio group. The product never saw the light of day. 

Perhaps vendors will take another look at a speaker/mic to add dual functionality in the field. Could one be built today with a screen on the back side and a complete FirstNet radio inside? If the speaker/mic was hardwired to a land mobile radio, could the FirstNet radio be powered directly from the LMR handheld? Some speaker/microphones include antennas that protrude from the top. These were designed to position the antenna higher than if it was in a holster on users’ belts. What possibilities lie within a speaker/mic housing beyond a FirstNet radio? 

Could an entire simplex land mobile radio reside in the speaker/mic housing with an external antenna mounted on the speaker/mic for off-network communications? Could Bluetooth be used as a communications command system to control both the LMR and FirstNet radios from a single speaker/mic? What else could the vendor community do with a speaker/mic to reduce the number of devices users need on their belts and to easily access each device? Perhaps such devices are already being designed and built, or perhaps this discussion will entice a vendor or two to cultivate different approaches. 

Until Next Week…

Andrew M. Seybold
©2020, Andrew Seybold, Inc.


2 Comments on "Public Safety Advocate: Off-Network Communications"

  1. Andy,
    Great column as always! I suggest that you tread lightly when you imply FirstNet has the ability to provide ‘secure’ communications. There is the RAN side. Private, yes. However, the subscriber unit uses channelized FDMA to talk-in and the emission can be ‘noticed’ within a local radius. There are techniques to be truly secure, just not in LTE or P25.

  2. Darek Wieczorek | July 1, 2020 at 1:08 pm | Reply

    Unless it already has been done, it might be very helpful to gather and provide some actual research data on off-network use of LMR. This is needed because we can only expect the pressure to switch from LMR to broadband to increase and we need data, rather than opinions, on how important off-network feature is to prevent switching agencies prematurely – and it will be premature for quite a while.
    Some scenarios are no-brainers, for example fire on-scene, but even in this cases it would be good to know whether this practice is in use 100% of the time, or less often? How often do trunked systems require the users to switch to simplex talk-around? For most of the well-maintained systems the answer is “never”, but, again, rather than relying on the anecdotal evidence, it would be good to have the actual numbers. How often do first responders find themselves in no/poor coverage areas and have to switch to simplex (and how do they coordinate such a switch)?
    Do you know if anyone has done this research already?

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