Which transmission method is used by the 802.11a Wi-Fi standard?

The 802.11a Wi-Fi standard employs Orthogonal Frequency Division Multiplexing (OFDM) as its transmission method. OFDM is a technique that divides a radio signal into multiple smaller sub-signals that are transmitted simultaneously at different frequencies. This allows for more efficient use of the spectrum and improves resistance to interference and multipath propagation, which are crucial in wireless communication environments.

In the context of 802.11a, the use of OFDM means that it can support high data rates up to 54 Mbps over the 5 GHz frequency band. This higher frequency band allows for less congestion compared to the 2.4 GHz band used by earlier standards, leading to improved performance and reduced interference from other wireless devices.

Understanding OFDM's relevance to 802.11a is essential as it showcases the advancement of wireless technologies in terms of speed, reliability, and efficiency, distinguishing it from earlier standards that used different methods like Direct Sequence Spread Spectrum (DSSS) or Frequency-Hopping Spread Spectrum (FHSS).