What method does the 802.11 standard use for frequency hopping?

The 802.11 standard utilizes two primary methods for modulation: Frequency Hopping Spread Spectrum (FHSS) and Direct Sequence Spread Spectrum (DSSS). These methods are designed to enhance the performance of wireless communication by spreading the signal over a wider bandwidth.

FHSS involves rapidly switching the carrier frequency among many different frequency channels, which minimizes interference and improves resilience against eavesdropping. This technique allows for dynamic frequency usage and can help avoid obstacles and reduce the impact of interference from other wireless devices.

DSSS, on the other hand, spreads the data signals over a wider bandwidth by multiplying the data signal by a sequence of pseudo-random bits, which also provides robustness against interference and improves overall signal integrity.

The other options represent different communication protocols or methods that are not specific to the frequency hopping utilized by the 802.11 standards. For instance, TDMA (Time Division Multiple Access) divides the channel into time slots but does not involve frequency hopping. CSMA/CD (Carrier Sense Multiple Access with Collision Detection) is employed in wired Ethernet networks and is not applicable to frequency hopping techniques. Orthogonal Frequency Division Multiplexing (OFDM) is another modulation method used in some types of 802.11 networks but does not