Motorola two way radios work almost like a cellular telephone in that they are used as a method of communication between people in different locations but there are a few major differences between the two way radio communication and telephone communication. The most noticeable difference between two way radio and telephone communication is that to the people talking on two way radios have to take turns talking -- this is called the 'half-duplex' mode of operation (telephone conversations, where people can be talking at the same time, uses what is called full-duplex mode). There are two frequency bands in use for two way radios these are the Family Radio Service (FRS) band and the General Mobile Radio Service (GMRS) band. The FRS band is specifically used for short-range communication between two way radios -- short range is defined as 2 miles or less. The GMRS band is used for two way radios uses that require longer range operation, where the users may be up to eight miles from each other. Some two way radios are only able to use the FRS band but almost all Motorola two way radios in commercial use are able to take advantage of both the FRS and GMRS bands. One important note about GMRS operation: The FCC regulates two way radios that operate on the GMRS band and requires users of this type of radio to obtain a license and pay a fee. The GMRS license is good for five years and costs $80.00; the license must be obtained by an adult (the radios operating under the license may be used by minors but only with the licensed adult's knowledge and permission). Go to the FCC's Internet page at: http://wireless.fcc.gov/services/index.htm?job=service_home&id=general_mobile for more information on GMRS licensing. Channels! There are 22 channels commonly used on two way radios: Channels 1 through 7 can be used by all two way radios whether they are using the FRS range or the GMRS range; channels 8 through 14 are reserved for used by radios using the FRS band and channels 15 through 22 are reserved for use by radios using the GMRS band. How this works in practical terms is pretty simple; basically, all the two way radios within eight miles of each other that are set to the same channel will be able to communicate with each other. The catch is, everyone with a radio receiver set to that channel's frequency will also be able to hear whatever is said -- so be careful about what you say. To combat that problem, most Motorola two way radios are also equipped with "privacy codes." These privacy codes will break up a single channel into many sub-channels which gives the radio users much more privacy. |
