Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly switching a carrier among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver. It is used as a multiple access method in the code division multiple access (CDMA) scheme frequency-hopping code division multiple access (FH-CDMA).
Each available frequency band is divided into sub-frequencies. Signals rapidly change (“hop”) among these in a predetermined order. Interference at a specific frequency will only affect the signal during that short interval. FHSS can, however, cause interference with adjacent direct-sequence spread spectrum (DSSS) systems.
Adaptive frequency-hopping spread spectrum (AFH), a specific type of FHSS, is used in Bluetooth wireless data transfer.