Updated
July 2012
In describing hand held portable radios, the catalogs go on about all the features with abreviations ie: GPS (Global positioning satellite) but what about VOX, FRS, GMRS?
Best answer - chosen by voters
FRS stands for Family Radio Service. GMRS stands for Ground Mobile Radio Service. They both use frequencies in the 462-468 MHz range. There are many 2-way radios now which are both FRS and GMRS. What’s the difference? The FRS service is fairly new, invented about a decade ago based on a petition to the FCC from radio manufacturers like Motorola and Radio Shack. People didn’t want to carry around huge CB walkie talkies anymore and the 49MHz band with all the cordless phones wasn’t cutting it for serious use. So, the FCC created an UNLICENSED band of 14 channels for walkie talkies. They limited power output to 500mW, and restricted radios to have NON-REMOVABLE ANTENNAS. These radios typically work a mile or two outdoors, largely depending on surrounding terrain and foliage. GMRS has been around a lot longer. GMRS is a LICENSED radio service. Unlike ham radio, a test does not need to be taken to acquire a license, just a form filled out and money sent in. You are then assigned a callsign and you and your family are permitted to use GMRS channels. GMRS users may also set up repeaters and are allowed higher power than FRS. They may also use EXTERNAL ANTENNAS. The range of these are a bit greater than FRS radios as the portables can go up to 5 watts typically, however with the assistance of a repeater, they can go 30 miles or further. There are a couple GMRS channels that are exactly the same as FRS channels, however only GMRS licensees may exceed the half watt FRS power limitation on these channels, and use external antennas.nGMRS repeaters may not be placed on those channels. All 2-way radios that are capable of using GMRS channels have a license application included in the box. To set an FRS/GMRS radio to operate on GMRS channels, you MUST be a licensed user. It is against the law to transmit on GMRS channels without a license and you can be fined a lot of money for doing so.