Push-to-Talk vs. Push-to-Talk over Cellular
Today I'm talking about push-to-talk communications (PTT for short) and push-to-talk over cellular (otherwise known as PTToC or just PoC).
I'm going to discuss the differences between them and the pros and cons of each.
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WHAT’S THE DIFFERENCE?
PTT radios can be analogue or digital. Digital radios (usually DMR) have many advantages over analogue, such as complex group calling, messaging, location tracking and emergency notifications, but they all have one thing in common.
All PTT radios talk directly to another radio on an independent radio network. It might be a simple case of one walkie-talkie transmitting directly to another on the same frequency, or there might be a slightly more complicated repeater setup where a base station up on a hill relays communication out to handsets across a larger area. Either way, they're doing their own thing.
PTToC, as the name suggests, uses mobile networks to relay communications to another handset. They support all the advanced features of Digital Mobile Radios and combine them with 4G and 5G bandwidth and nationwide coverage. It's pretty enticing and seems like a natural progression of all walkie-talkie communication, but there's a little more to it and whether you opt for PTT or PTToC depends on your use case.
I've been playing around with two radios before filming this video. On the PTT side is the Motorola DP4400e. It's the epitome of what a walkie-talkie should be. These things are the industry standard, and with good reason.
On the PTToC side, I've got the Motorola TLK 100. This radio is important in this context because, although it operates on a cellular network, it's essentially just a good old walkie-talkie.
Some PTToC radios have a blurred line between smartphones and radios. They're really just Android devices in a rugged case. The TLK 100 is different. The controls are simple, easy to operate, and the radio is built to last. You turn it on, set it to the channel you want, and you're good.
Let's talk about the benefits and downsides of each technology and go into a bit more detail about their differences.
RANGE
We couldn't film a video about walkie-talkies without discussing range!
Range and reliable reception are everything in radio communications. These radios operate at 4W high power on UHF around 450MHz, which gives them a decent range, even in a built-up area.
How can that compare to these, though? I can turn this on, leave it on my desk, drive 500 miles to Scotland, and chat with someone as if I'm in the next room.
If you're used to regular walkie-talkies, it's a remarkable and unusual feeling the first time you use PTToC. Although technically, they're not really doing much more than a voice call or data transmission on a mobile phone (something we do every day), it feels strange to drive around freely and know that when you press that button, you'll get a talk-permit tone and will be received in perfect clarity at the other end.
PTToC wins every time when it comes to range.
COVERAGE
Although closely related, range and coverage are not the same, and the distinction is important to highlight when talking about these two radio types. I'm sure someone out there has already said, "yeah, but what happens when there's no mobile reception?" Well, you're dead right.
These PTT radios take their coverage with them. The bubble of coverage is wherever these two are, flexing in and out depending on your surroundings. And that is the crucial difference. These can be used for mission-critical work. They have their own independent radio network reliant on nothing other than these two physically working.
Although mobile networks are used by EMS workers increasingly in the UK, there is still a reluctance to class this use as suitable for mission-critical applications.
What happens if you're a forester working in Kielder. I know from experience that mobile reception is virtually nonexistent. Equally, what happens if you're working in construction that takes you underground or just into some reasonably dense concrete structures. Can you guarantee mobile coverage? I very much doubt it. What about out at sea on a ship or even on an oil rig? There are still many scenarios where cellular coverage just isn't good enough, despite many outdoor coverage maps implying almost blanket coverage.
That said, before you write off cellular use, consider a few tricks these radios have up their sleeves to mitigate this shortcoming.
The SIMs in these are multi-network. You're not tied to e.g. EE or Vodafone. The radio will use whichever operator will do the job the best. So when looking into coverage, you need to look at all operators, not just one. It doesn't remove all blackspots, but it sure adds a few nice patches of coverage across the map.
The radios have a dedicated mobile antenna protruding clearly from the radio. People are used to mobile reception on phones that hide antennas for style and size purposes causing hands to potentially cover them and attenuate the signal. I can only imagine that an antenna like this will perform better in low-signal areas.
They can also connect via Wi-Fi, so if you're working in a facility with solid Wi-Fi throughout, you can get straight onto standard IP, and the world is your oyster. From there, you could speak to people across the globe with ease.
COST
This Motorola is top of the range and costs about £400-£500 per radio. I'm assuming no volume or account-related discounts here. On top of that, you have a suitable licence. In the UK, that's governed by Ofcom. It's difficult for me to guide you on what that would cost you as it depends on the number of radios and channels but that’s something that Radio Solutions can help you manage.
PTToC is actually pretty much the same. I would be reluctant to go with a cheaper unsupported brand when you need to ensure 100% compatibility with the mobile network operators in your country. The TLK 100 is about £350 for the radio but don't forget that jumping onto a mobile operator's network comes at a price. There's an annual subscription for all radios connecting to the networks. Without a subscription, the radios are bricks. Even the Wi-Fi doesn't work without a subscription. This could put some users off, but if radios are critical to your business, it's not a high cost and, if deployed correctly, can easily be made back through improved efficiency and communication.
AUDIO
Analogue PTT can sound great if you have a good radio and a strong signal. DMR can sound OK, but getting used to it takes some time, and the aggressive audio compression used in the DMR standard leaves a lot to be desired. Even a top-of-the-range radio like this can't make DMR sound good.
PTToC, on the other hand, completely blew me away. Bear in mind that I have only used this radio, but the clarity of the loudspeaker on the TLK 100 is the best in class, and the communications themselves are everything I wanted DMR to be. They sound crystal clear and easy to understand, and there is nothing else like it in the walkie-talkie world.
DEPLOYMENT & MANAGEMENT
Analogue PTT and many basic DMR deployments are entirely reliant on programming cables and computers to manage radios.
More advanced DMR setups do have over-the-air radio management, but for PTToC, this is standard. Programming cables are not a thing anymore when it comes to cellular radios, and every aspect of radio management can be carried out at any time from anywhere. It's how things should be.
I'd like to talk about this a bit more, but I don't have access to the management side of these radios, so I can't give you a demo of how this works. Maybe something for a future video?
CHOICE
PTT radios come in every shape, size and variant to suit every taste and requirement. It's insane how much choice there is out there and how many variants some manufacturers manage to produce for basically the same radio.
PTToC choice is growing, but right now, it's at a nice level. There are plenty of varied choices depending on what functionality you want, but not the hundreds of random radios to muddy the waters.
CONCLUSION
As you can see, these are two different technologies both with their own massive benefits.
If you need nationwide radio coverage, PTToC seems like the only choice. If you need to communicate across a smaller area but also be entirely self-reliant, PTT is your only choice.
There's lots of middle ground, though, and you either need to figure out the best option for yourself or, alternatively, you could contact Radio Solutions for assistance. They have years of experience and will be able to advise on what's needed to make your radio setup work for you.
For more information, visit the Radio Solutions website here.