Appendix D Wireless LANs
several intermediate rate steps between the maximum and minimum data rates. The IEEE 802.11g data rate and modulation are as follows:
Table 80 IEEE 802.11g
DATA RATE | MODULATION | |
(MBPS) | ||
| ||
1 | DBPSK (Differential Binary Phase Shift Keyed) | |
|
| |
2 | DQPSK (Differential Quadrature Phase Shift Keying) | |
|
| |
5.5 / 11 | CCK (Complementary Code Keying) | |
|
| |
6/9/12/18/24/36/ | OFDM (Orthogonal Frequency Division Multiplexing) | |
48/54 |
| |
|
|
IEEE 802.1x
In June 2001, the IEEE 802.1x standard was designed to extend the features of IEEE 802.11 to support extended authentication as well as providing additional accounting and control features. It is supported by Windows XP and a number of network devices. Some advantages of IEEE 802.1x are:
•User based identification that allows for roaming.
•Support for RADIUS (Remote Authentication Dial In User Service, RFC 2138, 2139) for centralized user profile and accounting management on a network RADIUS server.
•Support for EAP (Extensible Authentication Protocol, RFC 2486) that allows additional authentication methods to be deployed with no changes to the access point or the wireless stations.
RADIUS
RADIUS is based on a
•Authentication
Determines the identity of the users.
•Authorization
Determines the network services available to authenticated users once they are connected to the network.
•Accounting
Keeps track of the client’s network activity.
RADIUS is a simple package exchange in which your AP acts as a message relay between the wireless station and the network RADIUS server.
