802.11a pdf

WLANs are based on the IEEE 802.11 standard, which the IEEE first developed in 1997. The IEEE
designed 802.11 to support medium-range, higher data rate applications, such as Ethernet networks, and
to address mobile and portable stations.
802.11 is the original WLAN standard, designed for 1 Mbps to 2 Mbps wireless transmissions. It was
followed in 1999 by 802.11a, which established a high-speed WLAN standard for the 5 GHz band and
supported 54 Mbps. Also completed in 1999 was the 802.11b standard, which operates in the 2.4 - 2.48
GHz band and supports 11 Mbps. The 802.11b standard is currently the dominant standard for WLANs,
providing sufficient speeds for most of today’s applications. Because the 802.11b standard has been so
widely adopted, the security weaknesses in the standard have been exposed. These weaknesses will be
discussed in Section 3.3.2. Another standard, 802.11g, still in draft, operates in the 2.4 GHz waveband,
where current WLAN products based on the 802.11b standard operate.4
Two other important and related standards for WLANs are 802.1X and 802.11i. The 802.1X, a port-level
access control protocol, provides a security framework for IEEE networks, including Ethernet and
wireless networks. The 802.11i standard, also still in draft, was created for wireless-specific security
functions that operate with IEEE 802.1X. The 802.11i standard is discussed further in Section 3.5.