Frequency-hopping spread spectrum (FHSS) transmission is the repeated switching of the carrier frequency during radio transmission to reduce interference and avoid interception.

Working of frequency-hopping spread spectrum (FHSS):

In FHSS, the transmitter hops between available narrowband frequencies within a specified broad channel in a pseudo-random sequence known to both sender and receiver.

A short burst of data is transmitted on the current narrowband channel, and then the transmitter and receiver tune to the next frequency in the sequence for the next burst of data. In most systems, the transmitter will hop to a new frequency more than twice per second.

Because no channel is used for long and the odds of any other transmitter being on the same channel at the same time are low, FHSS is often used as a method to allow multiple transmitter and receiver pairs to operate in the same space on the same broad channel at the same time.

Benefits of using FHSS:

• FHSS is resistant to narrowband interference.
• Data signals are difficult to intercept if the frequency-hopping pattern is not known.
• Jamming is difficult if the frequency channel or hopping algorithm is unknown.
• An FHSS transmitted radio signal can share frequency bands with conventional transmissions without significant interference.