Various interpretations of P25 specifications hamper interoperability among radio systems.
Even when first responder agencies comply with the standards for making their radio systems interoperable, there's no guarantee they will be able to communicate in the field, an official at the Homeland Security Department told Congress on Thursday.
Project 25 is an open suite of standards public safety professionals developed for manufacturing interoperable two-way wireless communications products. But various interpretations of the standards have led to P25-compliant equipment that is unable to communicate with P25 products from other manufacturers or, in some cases, earlier versions of the same brand, said David Boyd, director of the command, control and interoperability division of DHS' Science and Technology Directorate. Boyd told the House Science and Technology Subcommittee on Technology and Innovation.
"There are lots of systems in the field labeled P25, but because of minor differences in interpretation, cannot communicate," which would cause major challenges in emergency situations that require first responders from different jurisdictions to talk to one another, he said.
"It seems to me, if they're not interoperable, one of the two systems should not be labeled P25 compliant," said subcommittee Chairman David Wu, D-Ore.
In 2008, Congress authorized DHS to establish the P25 Compliance Assessment Program in partnership with the National Institute of Standards and Technology to provide a certification process for suppliers' products. But "unfortunately, claims of compliance are not limited to the equipment that has completed the P25 CAP" testing, Boyd said. "This can lead to confusion among emergency responders and in the marketplace."
So far, four manufacturers have completed the P25 CAP process for their emergency communications equipment.
"The successful incorporation of conformance testing in the P25 CAP is dependent on manufacturer participation," Boyd said. "Without this rigorous testing, a P25 radio is compliant in name only."
Furthermore, development of the standards is ongoing, making true compliance impossible, said Dereck Orr, manager for the Public Safety Communications Systems program at NIST.
"As a result of the lack of complete standards, only a limited portion of a P25 system is truly standards based," he 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."
P25 compliance eventually will be defined by a core set of functionality requirements that does not change, Boyd said, even as manufacturers add "bells and whistles" to their products.
"We're getting close, but in the meantime, every new generation [of products] moves away from that [goal] and creates the exact same problem we're trying to fix," he said. "We need to get to a point where we don't have lots of diverging paths, but instead [standards that] allows us to move in the same direction, so the road gets wider."