By Robert M. Gurss

For years, the FCC has been working to encourage Part 90, private land mobile radio licensees to convert to more efficient, narrowband radio equipment.  The original equipment required 25 kHz channels.  As of January 1, 2013, licensees in bands below 512 MHz must operate on 12.5 kHz channels (or with equivalent efficiency).  That will require some licensees to replace very old radios, but equipment deployed since the late 1990s should already have 12.5 kHz capability.

The FCC recently clarified what it expects for the next step, conversion to 6.25 kHz channels.  There is currently no date by which such a conversion is required, and the FCC has said that it will monitor technology to determine when it may mandate such further “narrowbanding.”  Last year, the FCC had seemed to suggest that licensees now using 25kHz equipment might be required to go directly to 6.25 kHz.  This alarmed some licensees and equipment vendors who feared that users would hold off on the “immediate” step of going to 12.5 kHz capability. 

In response, the FCC released a order this week indicating that it had “not intended to dissuade migration to 12.5 kHz technology by licensees that have already begun the process.”  Nevertheless, the FCC reiterated that licensees who do not intend to convert from 25 kHz until shortly before the 2013 deadline “should consider the feasibility of migrating directly to 6.25 kHz technology.”   This continues to raise concerns, as it remains to be seen how 6.25 kHz technology will develop and whether it will meet the needs of all land mobile radio users.