Monday, September 1, 2008

Are You Ready for FCC Part 90 UHF/VHF Radio System "Narrowbanding"?

In December 2004, the FCC issued an Order mandating that all Part 90 business, educational, industrial, public safety, and state and local government VHF (150 – 174 MHz) and UHF (421 – 512 MHz) private land mobile radio (PLMR) licensees convert their radio system operations from legacy wideband (25 kilohertz) to narrowband (12.5 kilohertz or equivalent) operation by Jan. 1, 2013.

Contrary to what some may have heard or been led to believe, the Order does not require licensees to change to new radio frequencies or different frequency bands, nor does it require moving from analog to digital or from a conventional to a trunked radio system. (These are, though, alternative radio system options that some licensees may want to more fully explore with the guidance of a qualified radio communications system professional.) The Order also doesn’t mean that licensees need to replace all their current radio system equipment — only any soon-to-be-non-compliant equipment.

What the FCC’s mandate does require is that all wideband-only conventional or trunked VHF and UHF radios, including handheld portables, vehicle-mounted mobiles, dispatcher stations, wireless data, telemetry, or supervisory control and data acquisition (SCADA) link radios (called subscriber radios) and any associated wideband-only conventional or trunked base or repeater stations (called infrastructure radios), be replaced with narrowband capable equipment prior to the 2013 date to continue legal use of Part 90 radio frequencies beyond that date. FCC radio system licenses must also be modified to reflect the change to narrowband emissions and operation.

Migration Steps

Over the last several years, in response to the mandate, many licensees have started the narrowband migration process by deploying dual-mode subscriber radios — those capable of both wideband and narrowband operation — as new radios have been added to their systems or as older wideband-only radios were lost, damaged beyond repair or otherwise removed from service. While this strategy is a practical, cost-effective approach, particularly by those with large numbers of subscriber radios in their fleets or those with multiple radio frequencies, base stations and repeaters in their systems, this method addresses only the first step of a multi-step process.

Unless a radio system is initially implemented as a narrowband system - as most new systems have been during the past six to nine years - many dual-mode replacement subscriber radios deployed into pre-mandate or older, conventional or trunked VHF or UHF radio systems have typically been programmed for wideband rather than narrowband operation. This best-practices method was necessary to retain compatibility with existing wideband subscriber and infrastructure radios in use in those systems. (NOTE: the mixing of wideband and narrowband radios on the same frequency of a system is generally not encouraged nor recommended. Doing so has the potential to render most voice - and especially data - transmissions between wideband and narrowband radios unintelligible, distorted or unreliable). The method also allowed the expense of replacing infrastructure radios at the same time to be deferred, as the year 2013 seemed a long way off.

In many instances, however, the need to address the deferred replacement of wideband-only infrastructure radios may have inadvertently been overlooked or even forgotten by some licensees or radio system managers. This is particularly true when it comes to the many smaller business, educational, and industrial users of two way radio who typically don't keep up with current FCC Rules or the responsibilities that go along with being a Part 90 licensee, and, who quite often simply take the use and benefit of their radio systems for granted. This blog post is a reminder to all licensees that until all subscriber and infrastructure radios are fully migrated to narrowband operation, many radio systems may still be operating in the wideband mode, which is legal only until Jan. 1, 2013.

Migration Planning

Has your company or organization developed a migration plan and budget to address the next steps necessary to complete the narrowband migration process and become fully FCC compliant? These steps include replacing any remaining wideband-only subscriber radios still being used; procuring and installing narrowband base stations, repeaters or other infrastructure radios as needed; preparing a well-planned, coordinated approach to re-programming all radios to narrowband operation; and modifying a radio station license to reflect any new emissions designators. Click here for more migration suggestions.

The 2013 date isn’t that far away, particularly if funding needs to be secured and budgets prepared or, when any operations dependent on uninterrupted radio communications may be jeopardized. Companies and organizations that recognize and appreciate the value of their Part 90 two-way voice and data radio communications systems are advised not to wait until the last minute to begin or complete the narrowbanding process. By waiting, they are risking not only the loss of use of their current radio frequencies, but the return on the investment (ROI) and associated benefits provided by their radio system equipment as well.

More Information

Follow these two links to official documents and complete background information on the FCC’s narrowbanding mandate: (2004 Order) (2007 Update)

or, for on-line discussions regarding the mandate, licensees and other interested parties are invited to join the LMR Narrowbanding Yahoo! Group


1 comment:

MJM said...

I remember working on this policy at FCC in the early 90s. The Part 90 establishment wanted an endless transition to more efficient technology because of the cost and complexity - not to mention the competitive impact on certain vendors.

It is amusing to note that the whole TV industry and millions of consumers are making a shift to the more complex DTV technology in a much shorter time frame.