On January 1, 2013, all public safety and business industrial land mobile radio systems operating in the 150-512 MHz radio bands must cease operating using 25 kHz efficiency technology, and begin operating using at least 12.5 kHz efficiency technology.
This deadline is the result of an FCC effort that began almost 2 decades ago to ensure more efficient use of the spectrum and greater spectrum access for public safety and non-public safety users. Migration to 12.5 kHz efficiency technology (once referred to as Refarming, but now referred to as Narrowbanding) will allow the creation of additional channel capacity within the same radio spectrum, and support more users.
After January 1, 2013, licensees not operating at 12.5 KHz efficiency will be in violation of the dommission's rules and could be subject to FCC enforcement action, which may include admonishment, monetary fines, or loss of license.
For more information, visit the official FCC website about the VHF/UHF Narrowbanding Mandate.