General Mobile Radio Service - Frequency Assignments and FRS

Frequency Assignments and FRS

The GMRS-only channels are defined in pairs, with one frequency in the 462 MHz range for simplex and repeater outputs, and another frequency 5 MHz higher for repeater inputs. There are eight channels exclusively for GMRS and seven "interstitial" channels shared with Family Radio Service. GMRS use requires an FCC license, and licensees are permitted to transmit at up to 50 watts on GMRS frequencies, depending on the type of station, but 1 to 5 watts is more common. Units are allowed to have detachable or external antennas.

GMRS licensees are also able to use the first 7 FRS frequencies (the "interstitial" GMRS frequencies) with a few limitations. Specifically, they may be used as long as one-way pages are not transmitted, communications are limited to voice, and transmission power (ERP) does not exceed 5 watts (FCC Code §95.29, section f). This allows GMRS users to transmit on a total of 15 channels. FRS channels 8 through 14 are not available for GMRS use; use of these frequencies requires an FRS transceiver, or a hybrid transceiver operating under FRS rules.

Recently, hybrid FRS/GMRS consumer radios have been introduced with 22 channels, instead of the 14 channels associated with FRS. On this type of radio, channels 8-14 are strictly license-free FRS channels. Transmitting on all channels above channel 14 requires a license. Transmitting on the shared FRS/GMRS channels 1-7 requires a license, if using more than one half watt. It is the responsibility of the radio user to read and understand all applicable rules and regulations regarding GMRS. These hybrid radios are often referred to as "bubble pack" radios, since they are often packed in a plastic shell, for hanging on a display shelf. The massive sales of these radios have led to the term "bubble-pack pirates", persons who use GMRS without a license.

The FCC rules for use of hybrid radios on channels 1-7 require licensing only when operating under the rules that apply to the GMRS. Many hybrid radios have an ERP that is lower than one half watt on channels 1-7, or can be set by the user to operate at low power on these channels. This allows hybrid radios to be used under the license free FRS rules if the ERP is less than one half watt and the unit is certified for FRS operation. Only two makers of hybrid FRS/GMRS radios (Garmin and Motorola) presently sell radios that will operate on the GMRS repeater channels; the common "22 channel" radios cannot be used with GMRS repeaters. The Icom IC-F21GM is a solely-GMRS radio which will also work repeaters.