Are you ready for narrowbanding?

For radio systems operating at frequencies below 512 MHz, the FCC requires that the systems transition from 25 KHz channels to 12.5 KHz channels by Jan. 1, 2013. With a little more than four years left to meet the FCC mandate, affected licensees still have plenty of time to do the work, but many are overlooking operational issues that promise to complicate the migration, said John Facella, director for public-safety markets at Tyco Electronics Wireless Systems, formerly known as M/A-COM.

“I don’t think people have thought about this enough,” Facella said during an interview with Urgent Communications. “They’re thinking about their own parochial systems, and they’re forgetting that they have neighbors, mutual-aid agreements and the ability to operate on their neighbor’s system.

“It’s a freight train, and it’s coming down the track at 100 miles per hour.”

As has been the case in 800 MHz rebanding, public-safety agencies need to work together to ensure that interoperability is maintained throughout the narrowband migration. Without this coordination, there’s a very real possibility that mutual-aid partners will not be able to talk to one another if one has migrated to narrowband channelization and the other is still operating on 25 KHz channels.

In such a scenario, effective radio-to-radio communications will be difficult, if not impossible. A wideband radio talking to a narrowband radio will leave the narrowband user listening to a loud distorted signal, while the wideband user listening to a narrowband user likely will hear a low, noisy signal. Facella explained the situation with the following analogy:

“A wideband radio trying to talk to a narrowband radio is like a fat man trying to get through a narrow doorway,” Facella said. “He’s never going to fit, and you’re never going to see a complete view of his body and face, so you really don’t know who that is in the doorway. It’s the same thing with the voice—a good portion of the voice energy is going to be cut off, and it’s going to be so distorted that it’s going to be difficult to understand.

“A narrowband radio talking to a wideband radio is the opposite of that. It’s like you have a really wide doorway—representing the wideband radio—and three or four thin guys are going to be able to pass through that doorway, but they’re going to create a crowd in that doorway. One of those guys is the one you want to listen to, but those other guys are going to create the noise that you don’t want. That’s why it’s going to sound noisy.”

This issue can be addressed through a variety of strategies, but the key is for affected agencies to recognize the situation and begin planning for the challenges that the narrowband migration will bring, Facella said.

Aside from the technical issues, Facella noted that the economic downturn could make it more difficult for agencies to pay for narrowbanding, especially if they have not yet secured financing. In addition, those agencies waiting until the eve of the 2013 deadline to narrowband may want to consider stockpiling 25 KHz radios, which manufacturers will be prohibited from selling after Jan. 1, 2011, he said.

In addition, Facella said those overseeing radio systems must be proactive in educating elected officials and administrators about the 2013 narrowbanding mandate, which can be overlooked by those outside the industry because of other similar-sounding LMR efforts. These include the reconfiguration of the 800 MHz band and the reallocation of narrowband voice licensees operating at 700 MHz to the broadband portion of that band, in addition to the migration to the 12.5 kHz channels (i.e., narrowbanding).

“People who don’t understand the radio business get really confused,” Facella said.

Given the myriad challenges that will need to be met to comply with the FCC’s narrowbanding edict—so well articulated by Facella in our chat—procrastination isn’t advised. The next four years are going to fly by faster than you can imagine. If you don’t think so, just ask those who were tasked with the 800 MHz rebanding.

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