Frequency hopping (FH) is a radio transmission method that works with periodic frequency changes, in which the modulated carrier
frequency changes abruptly, hence the term frequency hopping technology. With frequency hopping, the number of frequency changes depends on the application and the frequency hopping variant. The frequency hopping technique (FHSS) used in WLANs and mobile radio networks operates with approx. 20 frequency hops per second
. In addition, thereare two other variants, slow frequency hopping (SFH) and fast frequency hopping (FFH).
In slow frequency hopping, several bits are transmitted per carrier frequency, while in fast frequency hopping the frequency changes occur during one bit duration. This means that a single bit is transmitted on one or more carrier frequencies.