Circumstances make P25, TETRA processes very different
By Donny Jackson
Oct. 24, 2006

It's only natural to make comparisons. For instance, no matter how many people recite the "it doesn't matter who wins" mantra at a Little League game, every player or parent paying attention can tell you the score of the game. It's human nature.

When evaluating something as important as public-safety communications standards, observers instinctively try to compare Terrestrial Trunked Radio (TETRA), the European standard, and Project 25 (P25), which is being developed for the North American market.

On the surface, TETRA has several clear advantages. Most notably, TETRA is a mature standard and is delivering on the promises of relatively inexpensive radios for its user base. Meanwhile, P25 until recently has consisted primarily of an over-the-air standard and the promise of many more to come. (The standard's inter-RF subsystem interface was finalized last summer).

P25 officials say such comparisons are unfair to both standards, which were developed under considerably different circumstances to address significantly different markets. Cynics may argue that such a stance is simply a tactic designed to deflect criticism of a P25 process that has generated few deployed standards after almost two decades of work, but there's little question that the scope of the P25 effort is much broader and much more complicated than the criteria TETRA satisfies.

Key differences between the processes include the fact that TETRA was designed to serve a given spectrum band cleared throughout Europe--a "greenfield" scenario that required little regard for existing communications systems. The European Union mandated that public-safety entities build communications networks to meet the standard, and these countries--many of which are no larger than U.S. states but typically more densely populated--were in an economic position to purchase the systems.

In contrast, the P25 effort faced considerably different challenges. Public-safety communications in the U.S. are not found in a single swath of airwaves; instead, such communications are scattered in pockets throughout the spectrum chart. Instead of developing a standard for greenfield deployments by well-funded entities, P25 attempts to address the needs of thousands of small public-safety entities that may not be able to buy a new system for 15 to 20 years, so technological backward compatibility is a must, no matter the complications.

In addition, while Europe's population is relatively dense, North American demographics dictate that public-safety agencies must be able to communicate in vast areas that offer little or no signs of civilization. Littering a desert in the western U.S. with relatively short-range TETRA-style towers makes little economic sense, so P25 must support longer-range communications technologies.

Given these challenging criteria, it's understandable that the P25 standards efforts--driven by volunteers--would take longer than the TETRA process. Could more have been done at a quicker pace? Probably, especially when judged against the accelerated P25 standards progress that has occurred since Congress made it a priority last year.

And, perhaps, that is the primary lesson to be learned. While the U.S. public-safety community is proud of its tradition of local control, leadership from the highest levels--be it the European Union or the U.S. federal government--often is needed to ensure that limited resources are utilized in an efficient, coordinated manner.

Hopefully, those within the Beltway will embrace this message as P25 evolves and several critical public-safety issues--from 800 MHz rebanding to 700 MHz broadband to next-generation 911--are decided during the upcoming months.

E-mail me at djackson@penton.com.

For P25, the best is yet to come
By Mary Rose Roberts
Oct. 24, 2006

Project 25, or P25, has been touted as the Holy Grail of interoperable communications. But as vendors are rolling out P25-complaint systems and equipment and customers increasingly are buying them, not everyone is convinced the standard and vendors' offerings, in their current form, are adequately meeting public safety's needs.

P25 is a common system of standards for digital, public-safety radio communications first conceptualized by the Association of Public-Safety Communications Officials (APCO) in 1989. Since its inception, supporters hoped the standard, when finalized, would provide a panacea to nationwide interoperability issues.

Some believe it has met its mark. Don Scott, Raytheon JPS Communications' vice president of business development, said P25 answered myriad questions stemming from an ineffectual public-safety communications system that differed from county to county and state to state. According to Scott, public safety's widespread use of incompatible systems stemmed from government-mandated, competitive-bidding processes, which let each public-safety agency choose its own system. P25, instead, is the basis for the ultimate solution: a nationwide system of interoperable equipment designed and built using a consistent set of engineering standards.

"P25 makes sense," Scott said. "Now it doesn't matter whose radio you buy. You can still talk to each other in the times when you need to."

P25 currently is being implemented by a large number of organizations, according to Kenneth Ballard, vice president and manager of technology at land-mobile-radio consultancy firm CTA Communications. He said several enterprise and public-safety clients' systems are already "on the air." However, this was not the case five or six years ago when few clients were willing to invest in an untested technology.

Clients didn't want to be guinea pigs for an unproven system, agreed Walter Karvetski, CTA's vice president of business development. "It wasn't really a system yet," Karvetski said. "Nobody was even making P25 [systems]."

P25 standard development and market acceptance has been a slow process, said Craig Jorgensen, chairman of APCO's Project 25 Committee. He points to the project's limited human resources because it is a volunteer-based group. In addition, agreeing on standards is a complicated process involving a meticulous review of engineering specifications and finding the appropriate balance.

"It's a complex process," he said. "It's not something you just throw together."

Nevertheless, Ballard said a majority of his clients now choose P25--especially if they are looking at replacement equipment or major upgrades to out-of-date systems. The change in mindset came as manufacturers moved product from R&D shelves to the marketplace, such as when M/A-COM's trunked P25 system became available, he said. Federal government funding and development of the inter-RF subsystem interface were among other key drivers.

"I think people are looking at it like it's almost illogical not to go with a P25 system," he said.

However, industry analyst Andrew Seybold, founder of Outlook 4Mobility, said P25 needs work. First, it is based on an older proprietary technology; consequently, the first-responder community pays more for an antiquated technology, he said. Second, first responders have not seen a true P25 radio that can interoperate effectively and reliably with other vendors' products. Often the equipment contains "bugs" that prevent them from interoperating with other devices, according to Seybold.

Jorgensen admits that P25 products entering the market may contain defects. But this is commonplace with any new technology, and the committee has been aggressive to ensure imperfections are resolved when they are brought to its attention, he said. A special committee was established and formalized in August 2005 to deal with known bugs or compatibility issues within P25 products, he added.

Manufacturers' decisions to add bells and whistles to systems in order to differentiate themselves in the marketplace are a major problem that also hurts P25 efforts, Seybold said. Specification interpretation also affects interoperability efforts.

"Everybody has their little tweaks to it," he said. "On the basic fundamentals, they probably talk OK to each other. But when you get into trunking, there is a marked difference because there is still an interpretation of what the specification is."

Features included in P25 radio systems are supposed to follow the standard, Jorgensen said. Yet he, too, has found that added features often have a negative effect on interoperability performance because they do not comply with the standard, which defines so-called standard options. Manufacturers wishing to add a proprietary option--even though it's similar to the standard option--must include the standard option in the product to ensure interoperability, Jorgensen said.

Value-added features are different. A manufacturer can include any value-added feature. While such features distinguish the technology from others in the marketplace, they also force users into purchasing only the specific manufacturer's systems going forward, Jorgensen said, negating one of the primary goals for P25: an open architecture that would let end-user customers purchase from any vendor. Consequently, caveat emptor--or buyer beware--has become a necessary mantra for those making purchasing decisions for first-responder agencies. Value-added features are not mandated by P25 to work across systems, and the committee does not force manufacturers into guaranteeing that these features support interoperability, as long as the standard options do.

"If there are features that the majority of users claim they need, they are standardized," Jorgensen said. "But if there are features some want and the majority doesn't, then that is something we don't worry about. It's up to the user."

The next step in the development of P25 is Phase II, according to Jorgensen. It involves time and frequency modulation schemes (e.g., TDMA and FDMA) with the goal of improved spectrum utilization. It entails work-console interfacing between repeaters and other subsystems, as well as worker-machine interfaces for console operators who facilitate centralized training, equipment transitions and personnel movement.

The P25 Committee feels positive about Phase II, Jorgensen said. He has seen significant progress and cooperation from manufacturers, which is allowing the committee to concentrate on the engineering attributes of the technologies being proposed and comparing them side-by-side.

"We believe the standards that come out of Phase II will represent the highest quality standard in the world," he said. "And we have no doubt about that."

Seybold sees interoperability as a decade-long process, involving trial and error and a review of the current standards.

"The only way we are going to get interoperability between departments on different bands is through an IP backend system, which is slowly beginning to take shape," he said.