Narrowband radio is a technology that uses a minimal amount of bandwidth. Many data and technologies usually associated with the narrowband radio can be adapted for transmission over the broadband and wide-band frequencies. The broadband bandwidth which handles a much wider range of frequencies, however, are not made to be handled by narrowband frequencies. This means that narrowband radios can only be used for narrowband technologies and data. Most broadband networks can support multiple traffic forms while narrowband is exclusive to support only one.
In radio communications, the term narrowband refers to the situation where the bandwidth of a radio message does not exceed its channel's approximate maximum bandwidth in a significant way. Channels with narrowband bandwidth often have a frequency response that can be deemed flat. It's a common belief and misconception that a narrowband radio signal occupies only a small section on the entire private licensed radio spectrum.
The United States Federal Communications Commission (FCC) has set aside this specific narrowband frequency range for radio services and mobile services. These services include paging systems used in emergencies or regular everyday personal use. Narrowband radio transmits and receives both analog and digital data over just a few kilohertz of bandwidth. A narrowband radio meets all the requirements set by the FCC in terms of usable bandwidth, which is very small when compared to its operating frequency.
In frequency modulation (FM) high-fidelity radio broadcasts, featuring both music and speech, narrowband frequencies are used for audio communications whether it is for amateur or commercial radio settings. Generally, wide band is used in FM broadcasts. Narrowband however, is also used to conserve precious bandwidth. For this reason, most narrowband frequencies are used in sending signals across long distances, including transmitting messages to outer space.
A narrowband radio modem is used by many licensed private radio stations that want to transmit data over a narrowband network. These modems usually transmit signals with low data rate. This is opposite to wide band radio's repeating frames of data being transmitted with extremely high data rates using microwave radio links. Together with cable modems, asymmetric digital subscriber line (ADSL) modems, and optical modems, the narrowband radio modem is still considered as one of the faster kinds of modems available in the world of communications. It's a specialized kind of modem compared to the more widely used ones, but it gets the job done for private radio stations that prefer to use narrowband more.