Interoperability Standards Stalled?

By Joseph Straw

Despite the clear need for interoperable communications standards, a decade of study has yielded only two of eight critical elements. Project 25, or P25, is the public-private initiative tasked with developing technical standards that manufacturers can use to ensure the interoperability of communications devices used by first responders in emergencies. But nearly two decades after the program launched in 1989, it is close to completing only two of the eight elements targeted.

The effort was slowed during its first 12 years by the competing interests of participating companies, which feared loss of competitive advantage if they worked together toward common standards. The human cost of communications failures on 9-11, however, pushed the need for interoperability to the political fore, and it created a business incentive: vendors saw the potential for more business if they could sell competing systems that worked together.

The eight separate elements of P25's planned standards, dubbed "interfaces," comprise all the different components of a public-safety communication system, including telephone connections, dispatch consoles, handheld radios, and data network connections.

The two most crucial elements of interoperability are closest to being finalized: standards for handheld radios and standards for connecting separate radio systems operating on different frequencies.

The first standard, covering handheld radios, is formally called the Common Air Interface. The standard would allow "talk around" between different manufacturers' radios bypassing encryption or other proprietary features, providing that they can operate at the same frequencies.

Although that standard was not yet finalized as of press time, manufacturers have already been selling "P25-compliant" radios that incorporate agreed-on elements of the incomplete standard.

The U.S. Department of Homeland Security (DHS) requires that radios bought with grant money be P25-compliant. Recently, however, the Government Accountability Office (GAO) urged flexibility, noting that compliant radios can cost twice as much, and may in fact not work across manufacturers—perhaps because of the not-yet-agreed-on portions of the yet-to-be-issued standard. (See "The Barriers to Interoperability," July).

But essential communication functions are interoperable in these P25-compliant models, maintains Grant Seiffert, president of the Telecommunication Industry Association, who wrote lawmakers in response to the GAO report, explaining that while some P25-compliant radios feature proprietary add-ons that are not interoperable with other manufacturers' radios, their basic functions are.

GAO also criticized the lack of testing, but Seiffert noted that early this year manufacturers EADS and M/A-COM conducted an independent test, achieving interoperability between P25-compliant radio systems built by each manufacturer.

Speaking recently at a DHS Office of Interoperability and Compatibility Roundtable in Washington, D.C., David G. Boyd, DHS's head of command, control, and interoperability, predicted a sharp drop in the cost of P25-compliant radios with the finalization of standards. He said that will draw more manufacturers into the market, which will drive down prices.

The second protocol nearing completion, is called the Inter RF Subsystem Interface, or ISSI. It would link separate radio networks regardless of frequency, jurisdiction, or location, via landline.

An initial draft of the ISSI protocol was first issued early in 2006, and manufacturers are in the process of developing compliant equipment, says Dereck Orr, a program analyst with the National Institute of Standards and Technology assigned to Project 25. Testing guidelines for ISSI compliance are expected next year. v

Public safety and emergency response jurisdictions are already requiring that vendors be ISSI-compliant in contract requests, Orr says. So, with regard to that standard, "we're right on the verge" of field implementation.

While less critical to interoperability in the field, Orr says the six remaining P25 standards, which govern dispatch consoles and other major network equipment, will be the most difficult to finalize because of the proprietary nature of the functionality they address.

What remains to be seen is the extent to which U.S. states and territories will tie P25 compliance to their individual interoperability plans; plans are due to DHS November 1, and it's clear that P25 remains a work in progress.

In the long term, officials hope that Voice over Internet Protocol (VoIP), or software-defined radio (SDR) will render the interoperability issue moot. For now, however, use of VoIP is limited by mobile coverage and bandwidth limitations, while SDR is in early development, primarily by the Department of Defense.



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