What describes the functionality of both DSSS and FHSS?

Both DSSS (Direct Sequence Spread Spectrum) and FHSS (Frequency Hopping Spread Spectrum) are categorized as spread spectrum techniques, which is what makes this choice the correct answer. Spread spectrum techniques are employed primarily in wireless communication to enhance the robustness and reliability of signal transmission by spreading the signal over a wide bandwidth.

DSSS works by combining a data signal with a pseudo-random noise signal, which spreads the transmitted signal over a wider frequency band. This makes it more resistant to interference and jamming. FHSS, on the other hand, transmits the signal by rapidly switching the carrier frequency among many frequency channels, which helps in avoiding interference and provides a level of security against eavesdropping.

In contrast, the other options either describe functions that are specific to one of the techniques or do not accurately reflect the fundamental characteristics shared by both. For instance, while spectrum management is important in wireless communications, not all spectrum management techniques specifically characterize the operation of DSSS and FHSS. Likewise, the involvement of multiple frequency channels is more closely associated with FHSS, as DSSS uses a broader frequency band rather than multiple discrete channels. Lastly, stating both are used for high-speed internet connections doesn't encompass the primary purpose of either method,