Updated: Sonim Technologies says SLED accessory on LTE smartphone will support direct mode, P25 trunking, ad-hoc gateway

[Editor's note: Article updated to include prospective pricing for the XP8-SLED package.]

LAS VEGAS—Sonim Technologies’ P25 accessory to its XP8 rugged smartphone will support full P25 conventional trunking and ad-hoc interoperability gateway functionality, in addition to providing high-powered, direct-mode communications, a company official said yesterday during an APCO 2018 session.

Known as the Sonim LMR Enabled Detachable (SLED), the accessory was demonstrated to provide direct-mode voice communications during the IWCE 2018 event in March, according to Bob Escalle, senior director of public-safety and defense markets for Sonim Technologies. Now, a revised version of the SLED includes other features requested by public-safety officials, he said.

“We’re also supporting a full P25 conventional trunking SLED that attaches to our device, as well,” Escalle said during the APCO 2018 session. “The idea is that you can actually bring a very cost-effective, fully CAP-approved P25 handheld with a smartphone device.

“Some people talk about moving from an LMR radio and putting broadband applications on the LMR radio. We’re kind of going in the opposite direction by putting P25 accessory onto our device. If you need it, you can use it; if not, then you have a smartphone with a mission-critical PTT application on there via broadband.”

In addition, Sonim Technologies has established a gateway functionality on the device, leveraging the ability for a SLED-accessoried Sonim XP8 smartphone to communicate with both FirstNet and P25 networks, Escalle said.  

“The other nice thing is that … your smartphone now becomes a quick, ad-hoc IP gateway— narrowband in [and] broadband out, or broadband in [and] narrowband out,” he said. “So, you can imagine going into gateway mode, and this becomes your quick, ad-hoc gateway product for those who either don’t have broadband devices at a scene that may get [access to broadband users].”

During an interview with IWCE’s Urgent Communications, Escalle said the SLED gateway will have the same functional capabilities as dedicated gateways, with some expected limitations.

“The idea is not to replace those dedicated gateways,” Escalle said during the interview. “Some of those gateways have advanced features that we’ll never support. But, for just a quick-and-dirty [interoperability solution], I can go to gateway mode, and I can support people who don’t have a broadband device—or broadband guys who don’t have a narrowband device—and now I can talk between them, just by setting up this simple gateway.

“As long as it’s receiving a transmission from a P25 talk group or a conventional channel, it will take it and rebroadcast it across the LTE channel. It will only handle one talk group at a time, but that’s all a P25 handheld will handle. It will go in and out, both directions. [And] You are limited by the battery power of the unit, unlike a gateway that might be plugged into the wall or a 12-volt battery. You’re going to be limited by the [battery] capacity of your XP8.”

Of course the Sonim XP8-SLED package is still designed to provide direct-mode voice that is comparable to LMR radios, thanks to the 5-watt power level available in the VHF version of the accessory and the 4-watt power level available in the UHF and 700/800 MHz versions of the SLED, Escalle said during the APCO session.