IEEE 802.11a

The 802.11a standard was released in September 1999 and supported devices using the 5 GHz range. In ideal conditions, this standard had a speed of 54 Mbps and had an indoor range of 35 m.

To make more efficient use of the available bandwidth, 802.11a utilized a modulation technology called Orthogonal Frequency Distribution Multiplexing (OFDM). This technique broke the 20 MHz channels used by this frequency range into 52 sub-carriers per channel. Each sub-carrier had a bandwidth of 312.5 KHz, and therefore had a lower data rate than a full channel. While this may seem counter-intuitive, it actually worked quite efficiently as the number of sub-carriers meant the overall data rate was better. An analogy may be beneficial here. ...

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