A nearly impossible job

Sep 1, 2009 12:00 PM, By Donny Jackson (donald.jackson@penton.com)

Agencies with financial and personnel resources to pursue new buildouts find public-safety spectrum is at a premium.

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For frequency coordinators serving the public-safety community, it may seem that the only constant is change, which has made their tasks increasingly difficult in recent years, even though the big influx of applications associated with narrowbanding below 512 MHz is only just beginning.

“The bottom line is that, with more and more demand for radio communications, when somebody comes to us and says, ‘I need a channel for this,’ or ‘I need five channels for a trunked system,’ it is a real challenge to find them,” said Ralph Haller, chairman of the National Public Safety Telecommunications Council (NPSTC) and executive director of the Forestry Conservation Communications Association (FCCA).

“It is almost an impossible job to find frequencies for all the stuff that people want. … People bring [their ideas to build or expand systems on new spectrum] and you just throw up your hands and say, ‘How are we going to do that?’”

It's not that all airwaves in the public-safety bands are used, but most agencies with the financial and personnel resources to pursue new buildouts typically serve populous areas of the country, where public-safety spectrum is at a premium. This is particularly true in the UHF and VHF bands, where the spectrum has better propagation characteristics — i.e., greater range and the ability to penetrate though foliage — than in the 700 MHz and 800 MHz bands.

“If we could take open spectrum in rural Nebraska and use it in New York, there wouldn't be a problem, but you can't do that,” Haller said.

More spectrum in the VHF and UHF bands could become available as agencies move from 25 kHz channels to 12.5 kHz channels as part of the FCC mandate to narrowband systems below 512 MHz by Jan. 1, 2013. In fact, the FCC has expressed its intent to move to 6.25 kHz-equivalent channels in these bands eventually, but no dates have been established for that migration.

At the very least, each licensee in these bands will have to change the emissions designator for their systems when they narrowband, said Alan Tilles, who represents several public-safety agencies as a partner in the law firm of Shulman Rogers Gandal Pordy & Ecker. In addition, frequency coordinators will be receiving new applications for spectrum in the band from licensees hoping to take advantage of the more efficient use of airwaves enabled by narrowbanding.

“The hard part will be all the new applications for opportunities that are now becoming available because of narrowbanding,” Tilles said. “Those require, in many cases, a higher level of review than perhaps applications did in the past. You have to be a lot more careful with regard to channels that are adjacent, in order to find holes, so to speak.”

As with many transitions, timing may be crucial in terms of which new opportunities are granted in VHF and UHF, Haller said. And the approach frequency coordinators will take in the band likely will be decidedly different after the 2013 deadline passes, he added.

“Right now, in coordinating, we have protect the incumbent wideband licensees,” Haller said. “That prevents coordinating some channels that would otherwise be available in an area if everyone were narrowbanded.

“Once we quit protecting the wideband licensees [after 2013], that will open up some opportunities that today we can't do because there would be unacceptable interference.”

Although narrowbanding is designed to double — at least — the spectral efficiency of communications systems below 512 MHz, Haller emphasized that there will not be twice as many channels available for new opportunities. Because of the manner in which VHF and UHF bands are used — and the fact some licensees already are on narrowband channels, using systems that double capacity but do not necessarily make spectrum available — Haller said he “conservatively” projects a 10-25% increase in new available channels after narrowbanding.

Meanwhile, frequency coordinators are increasingly concerned that many public-safesty officials are not aware of the narrowbanding mandate or do not fully comprehend its implications and consequences, Haller said.

“There's a lot of misunderstanding,” he said. “There are a lot of people out there that think they will just become secondary in 2013 [if they do not narrowband]. That's not true. … You don't become secondary, you become illegal.”