Which wireless technology transmits short bursts of data on a particular frequency within the band and then moves to the next frequency in the sequence?

Which wireless technology transmits short bursts of data on a particular frequency within the band and then moves to the next frequency in the sequence?

• A. DSSS (Direct Sequence Spread Spectrum)
• B. FHSS (Frequency Hopping Spread Spectrum)
• C. OFDM (Orthogonal Frequency-Division Multiplexing)
• D. CSMA/CA

Answer: (B)

The concept being tested is frequency-hopping spread spectrum. In this approach, the transmitter sends data in short bursts on one frequency within a band, then rapidly moves to the next frequency in a predefined sequence and repeats. The data is effectively spread across the band over time because the transmission hops through multiple frequencies, and the receiver—knowing the hopping pattern—follows along in sync to recover the data. This technique helps mitigate interference and makes the signal harder to jam or eavesdrop. By comparison, Direct Sequence Spread Spectrum keeps transmitting on the same frequency but spreads the signal over a wider bandwidth with a spreading code; Orthogonal Frequency-Division Multiplexing divides the channel into many subcarriers and transmits across them in parallel on the same overall band; CSMA/CA is a method for accessing a shared medium rather than a way of spreading the signal across frequencies.

The concept being tested is frequency-hopping spread spectrum. In this approach, the transmitter sends data in short bursts on one frequency within a band, then rapidly moves to the next frequency in a predefined sequence and repeats. The data is effectively spread across the band over time because the transmission hops through multiple frequencies, and the receiver—knowing the hopping pattern—follows along in sync to recover the data. This technique helps mitigate interference and makes the signal harder to jam or eavesdrop. By comparison, Direct Sequence Spread Spectrum keeps transmitting on the same frequency but spreads the signal over a wider bandwidth with a spreading code; Orthogonal Frequency-Division Multiplexing divides the channel into many subcarriers and transmits across them in parallel on the same overall band; CSMA/CA is a method for accessing a shared medium rather than a way of spreading the signal across frequencies.