Just because a manufacturer says its land mobile radio is interoperable and compliant with Project 25 standards doesn't mean it's actually interoperable, government officials testified May 27 before a House panel.

Project 25 is a 21-year public-private effort establish interoperable standards among makers of land mobile radios, which are the primary method of voice communication among first responder agencies.

But, testing by the Homeland Security Department a few years ago showed that "much of the equipment advertised as P25 compliant was unable to interoperate with P25 equipment manufactured by other companies," said David Boyd, director of the command, control and interoperability division within DHS's science and technology directorate.

In many cases, P25 radios weren't even compatible with earlier P25 equipment manufactured by the same company, Boyd added. He testified before the House Science and Technology subcommittee on technology and innovation.

That discovery led to the establishment in 2008 of a P25 compliance assessment program at DHS in coordination with the National Institute of Standards and Technology and since then four manufacturers have gone through standards compliance testing, Boyd added.

However, P25 standards are far from complete, meaning that any system with P25 components can easily not be fully interoperable with in full. There are eight standards that comprise P25, but only the standard specifying the interface for wide area network connectivity between radio frequency subsystems and the conventional standard for processing digital voice signals is complete, said Dereck Orr, NIST's program manager for public safety communications systems.

"As a result of the lack of complete standards, only a limited portion of a P25 system is truly standards based," Orr said. "Standards are a blueprint to allow multiple vendors to build products. In the absence of that blueprint, you cannot have the common implementation that allows for interoperability."

The standards process has been slow, most panel witnesses said.

"This, by any sense, is a fairly small, specialized industry," said Ernest Hofmeister, a senior scientist at radio manufacturer Harris Corp. "The scale makes a difference in the amount of resources that can be devoted to standards."

First responder charges of a lack of systematic interoperability between P25 radios might not be correct, said John Muench, director of business development at Motorola, a large manufacture of first responder LMRs.

In the majority of cases since 2005, the lack of interoperability has been due to misconfiguration, Muench said. "This is a complex technology, this isn't plug and play like you have on your Apple computer," he added.

For more:
- see the House Science and Technology subcommittee on technology and innovation hearing webpage, complete with links to a webcast and prepared statements

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