Motorola today announced that it is the first vendor to complete the first part of Phase 3 testing that is being conducted by the Public Safety Communications Research (PSCR) program at the U.S. Department's laboratories in Boulder, Colo. The testing is being performed to demonstrate public-safety broadband network interoperability.

Specifically, Motorola and Ericsson — companies that entered into an alliance in September 2010 to develop an LTE-based public-safety broadband communications solution — collaborated to demonstrate interoperability of the solution's radio access network (RAN) and evolved packet core (EPC) with three major network vendors.

"[We took] the eNodeBs — the base sites, if you will, for LTE — from one vendor, including ourselves, and made sure that they would work with the LTE core of other vendors — whether it was Alcatel-Lucent, NSN [Nokia Siemens Networks] and I think maybe Cisco was involved," Bob Verbiscer, Motorola's senior director for public-safety broadband engineering, said during an interview.

"We then reversed that process, connecting the other vendors' eNodeBs to the network core of our solution. One of the primary goals of FirstNet and NIST is to ensure that this is 3GPP-compliant technology that leverages industry standards, to make sure that the equipment is interoperable amongst all of the various players."

Phase 3 also involved network drive testing, during which Motorola demonstrated the performance of a single LTE network in an operational environment, according to a company press release. Key components of the drive test included intra-LTE handoffs, network coverage, network load and stress, and application messaging/protocol performance.

The testing process started about two years ago with Phase 1, which Motorola completed in January 2012. That phase was designed to demonstrate the basic operability of 700 MHz Band 14 networks, that Band 14 devices could attach to the network, and that basic applications could perform across the network.

"Transferring data back and forth, some simple voice-type operations, database operations, things of that sort," Verbiscer said.

He added that a second phase — designed to test the data-throughput thresholds of LTE under various conditions — was planned, but NIST later scrapped it.

Considering that this latest testing initiative was classified as "part one" of Phase 3, it's safe to say that subsequent parts, as well as additional phases, are in the offing, Verbiscer said.

"Nothing has been shared with us yet, but I expect that the NIST team will have further testing as things go forward," he said. "As FirstNet solidifies their directions and the things that they want to do, I'm sure that NIST will set up testing to support those goals."