Pryme Radio Products is now working with Zello, a cellular data walkie-talkie app developer, to transform the way that public safety professionals communicate. The Zello app can run on any smartphone over WiFi or over 4G networks to provide secure push-to-talk (PTT) communications.

Dave George, Pryme's founder and president, says the company has been building its relationship with Zello since 2014. He believes PTT communications over smart devices will soon be commonly in use in law enforcement, as the line between land-mobile radio and cellular communications continues to blur. "We are seeing many law enforcement agencies using PTT over smartphones," George says.

The advantages of using PTT apps such as Zello over smart devices are many, according to George. Not only can users communicate securely from literally anywhere with an LTE cellular signal, including from space. They can review the content of the message after its been sent. "On Zello you can hear the messages live and replay them," George says.

Communications professionals have long believed that cellular and radio communications would be combined in single hybrid devices used by first responders. Currently, however, PTT over cellular (POC) apps that run on smartphones are the most visible evidence of this trend.

Pryme forged its relationship with Zello so that Zello users can operate the app in much the same way as they would a PTT radio over a Pryme accessory. "Using Zello and a very radio-like product that Pryme makes, you can communicate over POC without removing your phone from your pocket," George says.

So far law enforcement has been slow to adopt PTT over cellular primarily because officers don't have agency-issued smart devices, but George says he's seeing more agencies acquire smartphones for their officers. He believes agencies will be more likely to use apps like Zello if they can access them using familiar technology such as their radio mics. "The closer you can make the new stuff look like the old stuff, the faster they will be comfortable with it," he adds.

George says the company's PTT accessory will work on smartphones running Zello and on a wide variety of radio systems and the same mic can be used for both. "We can make a version of your portable radio mic for your smart devices with all the same attributes as your radio mic," he says.

At last month's International Wireless Communications Expo (IWCE), Pryme and Zello announced that they are collaborating to make PTT-over-cellular communications easier on Android smartphones. "Pryme and Zello have been working together for a while on this technology, which allows for a button that you don't need to charge," says Zello's Nayeli Cortina. Both Pryme and Zello believe this breakthrough will make PTT over cellular more attractive for law enforcement agencies because many law enforcement agencies prefer Android smart devices.

Cortina says one of the advantages of the Zello app over some other PTT-over-cellular solutions used on smart devices is that it runs in the background and remains on until the user closes the app. That means the user doesn't have to turn on the app each time it's needed and messages will not be missed. "As long as Zello is on, you will be receiving the messages live," she says.

Not only can Zello be used anywhere there is 4G or WiFi service, it's much more secure than radio. Zello messages are secured by advanced encryption, says Cortina. "You can't listen in on Zello conversations," she adds.--David Griffith