What is IEEE 802.11 Legacy? - Explained

The initial stage of WiFi is started with the IEEE standard for Wireless networking released in 1997 and elaborated in 1999. 

Technology

At the initial stage of the standard, the 802.11 legacy protocol was capable only to transmit two data rates which were 1 Mbit/s and 2 Mbit/s.

Infrared was popular back in the time to transfer data in wireless, and IEEE planned to transfer the data by using IR or by using 2.4GHz which was free to use under Industrial Scientific Medical Frequency Category.

Though IR wasn't used to implement the 802.11 wireless legacy protocol, Frequency Hopping and Direct Sequence Spread Spectrum (DSSS) used to implement the IEEE 802.11 legacy wireless communication protocol.

There were multiple devices that appeared in the market with wireless technology and the DSSS version of 802.11 legacies was popular.