FCC Narrowband Mandate

Narrowbanding in a Nutshell

• Today most land mobile radio (LMR) systems in the VHF (150-174 MHz) and UHF (421-512 MHz) bands use channel bandwidths of 25 kHz.

• In an effort to free up more communication spectrum, the Federal Communications Commission (FCC) has mandated that all licensees using wideband 25 kHz channel bandwidths convert to narrowband 12.5 kHz channel bandwidths by January 1, 2013.

• “Going digital” is NOT required to meet the narrowband mandate.  You may continue to operate analog narrowband equipment after the January 1, 2013 deadline. However, if you regularly communicate with other agencies or users, they may “go digital” and their action will force a decision on your part. Each such situation will require careful consideration of costs and operational tradeoffs.

• Narrowbanding is NOT optional. You cannot simply ignore the FCC’s narrowbanding rules. If you are using the VHF and/or UHF land mobile bands and not currently operating narrowband equipment, you will be affected. Your existing wideband system will need to be modified or replaced by January 1, 2013, and organizations that do not meet the deadline face the loss of communication capabilities. Legal or punitive actions might also be applied.

• In many cases, radios operating narrowband will not exhibit the same “talk power” (that is, the ability to communicate over a given distance or area) as today’s wideband radios. Particularly if your radio communications capability is “mission critical”, you should review your communications requirements and plan for needed changes before the mandate becomes effective.

• Many current model LMR radios are already “dual bandwidth” capable – meaning they can be programmed to operate in wideband channel bandwidths or in narrowband channel bandwidths.  Therefore, if you have “dual bandwidth” capable radios, meeting the FCC narrowband mandate does not necessarily mean buying new radios.  However, some older radios may have the capability to utilize narrowband channel bandwidths, but yet not provide the channel spacing required in the new band plans. Those radios may need to be replaced.

• Using mixed wideband and narrowband radios on the same frequency is not reccomended. Voice communication from a wideband radio to a narrowband radio will sound loud, distorted, or inaudible. On the other hand, narrowband voice communication to a wideband radio will be soft, quiet, or missed. Further, narrowband radio signaling tones or codes may not open-up the receiver of a wideband radio.

• Organizations need to start planning now to migrate to narrowband systems by assessing their current communications requirements and radio equipment and applying for new or modified licenses.

• We will be prepared to help you make informed decisions about how you implement narrowbanding in your communications system or systems.  Contact us for help with your narrowband conversion.

Copyright © 2009 Industrial Communications

See the following FCC document regarding the narrowband decision: http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-04-292A1.pdf