Civilian Use
Since the Federal Communications Commission (FCC) amended rules to allow frequency hopping spread spectrum systems in the unregulated 2.4 GHz band, many consumer devices in that band have employed various spread-spectrum modes.
Some walkie-talkies that employ frequency-hopping spread spectrum technology have been developed for unlicensed use on the 900 MHz band. Several such radios are marketed under the name eXtreme Radio Service (eXRS). Despite the name's similarity to the FRS allocation, the system is a proprietary design, rather than an official U.S. Federal Communications Commission (FCC) allocated service.
Read more about this topic: Frequency-hopping Spread Spectrum