An IEEE wireless networking standard established in 1999, 802.11b operates in the 2.4 GHz frequency band with maximum data rates of 11 Mbps. It uses direct-sequence spread spectrum (DSSS) modulation, a method that spreads the transmitted signal over a wider frequency range, which helps to reduce signal interference and improve stability over longer distances.
The 2.4 GHz band allows for greater range and better penetration through obstacles like walls, making 802.11b suitable for residential and office environments where physical barriers may be present. However, this band is also shared with various household devices, such as microwaves and cordless phones, which can lead to interference issues. While 802.11b offers slower speeds compared to later standards, its longer range and low-cost implementation made it a popular choice in the early days of Wi-Fi.
802.11b devices are backward-compatible with later 2.4 GHz standards, such as 802.11g, but they are incompatible with devices that operate solely in the 5 GHz frequency band, like those based on 802.11a.