WLAN Technology Background

  • Article

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

The WLAN solution provided by Windows XP and Windows Server 2003 is based on IEEE standards 802.11 and 802.1X.

IEEE 802.11   IEEE 802.11, the standard for WLANs, specifies a technology that operates in the 2.4 through 2.5 GHz Industrial, Scientific, and Medical (ISM) band and has a maximum bit rate of 2 megabits per second (Mbps). IEEE 802.11b supports two additional speeds, 5.5 Mbps and 11 Mbps, in the ISM band.

Note

  • The latest IEEE standard, IEEE 802.11a, specifies a technology that operates in a 5.725 through 5.875 GHz band with a maximum bit rate of 54 Mbps.

The 802.11 standard defines an access point (AP) as a device that functions as a transparent bridge between the wireless clients and the existing wired network. The AP contains at least one interface to connect to the existing wired network, and transmitting equipment to connect with the wireless clients. The AP also contains IEEE 802.1D bridging software, thereby acting as a transparent bridge between wireless and wired data-link layers.

IEEE 802.1X   The 802.1X standard defines port-based network access control to provide authenticated network access for Ethernet networks. This port-based network access control uses the physical characteristics of the switched LAN infrastructure to authenticate devices attached to a LAN port. Access to the port can be denied if the authentication process fails. Although this standard is designed for wired Ethernet networks, it applies to 802.11 WLANs as well.