3470 Manchester Rd, Akron, OH.44319, USA
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To using our knowledge and experience in a cost-effective manner to promote the use of two-way radio products to solve problems and increase productivity and safety.
Narrowband Explained
Narrowband_explained_simply.doc
Background
In 1996, the FCC began an initiative to make more radio channels available for high power use in the VHF HIGH (150-174 Mhz) and UHF (406-512 Mhz) frequency bands. The block of radio frequency spectrum within these bands is divided into hundreds of small slices, or frequencies and assigned on a first-come-first-serve basis to radio users. In metropolitan areas where radio systems on these bands are common, there are not enough slices available to serve everyone. Therefore, the FCC is dividing the bands into smaller slices to double the capacity. This requires a change in the radio hardware to prevent overlapping signals. The current, wider slices, which are 25 kilohertz wide, are called “wideband”. The newer smaller slices are 12.5 kilohertz and are referred to as “Narrowband”.
Deadlines
The FCC has set January 1st, 2013 as the final date for all Licensees within the VHF and UHF bands to convert their radio systems to narrowband operation. Any new systems licensed after January 1st, 2011 must be narrowband only. Any existing wideband systems that need to make certain modifications After January 1st 2011 that will increase the service area must convert to narrowband. These modifications could include adding or changing frequency, increasing antenna height or power output and moving a base or repeater station. Any systems that continue to operate in wideband mode after January 1st, 2013 will be violating FCC Rules and will be subject to fines and revocation of licenses.
Conversion
Beginning in 1997, the FCC has required all new radios submitted for Type Acceptance to be sold in the United States should have narrowband capability. Most radios sold since 1997 are programmable by the Dealer for wideband or narrowband on a channel-by-channel basis using a PC and special software. Therefore, narrowband conversion often can be done simply by re-programming the radios. Radios that are too old to have narrowband capability will have to be replaced. Your FCC License will also need to have a modification to tell the FCC you are switching to narrowband.
What’s next?
The FCC has made it clear that they intend to split the frequencies again at some point in the future. There has not been a date set for the next split. When this occurs, the new slices will be 6.25 Kilohertz wide. A digital radio is required to maintain good communications on channels that narrow. A few Manufacturers have been selling digital capable radios for several years. Beginning January 1st, 2013 all new radios submitted to the FCC for Type Acceptance must have a 6.25 KHz mode. Additionally, Any radios imported to the U.S. or manufactured in the U.S. after January 1st, 2013 cannot have wideband capability.
Jeff Mitchell
Mitchell Communications Inc
Updated Aug. 11, 2010