Narrowbanding is an FCC-mandated change that applies to all VHF High Band (150-174 MHz) and UHF (420 to 512 MHz) systems. All systems and equipment must operate in the narrowband mode by January 1st, 2013.

If you maintain your own VHF High Band or UHF system, it will likely need to be upgraded or modified by 2013 to operate in narrowband mode. Your radios, pagers and firehouse receivers, if they are narrowband-capable, will need to be reprogrammed when the system is upgraded. If your radios and pagers are not narrowband capable, they will need to be replaced.

To learn more, visit:
http://butlersheriff.org/radio/users/guides/narrowbanding/