ZyXEL Communications MAX208M2W SERIES, User Manual

Page: 70 / 200

Chapter 6 WiMAX
MAX208M2W Series User ’ s Guide
70
WiMAX technology uses radio signals (around 2 to 10 GHz) to connect subscriber
stations and mobile stations to local base stations. Numerous subscriber stations
and mobile stations connect to the network through a single base station (BS), as
in the following figure.
Figure 20 WiMAX: Multiple Mobile Stations
A base station ’ s coverage area can extend over many hundreds of meters, even
under poor conditions. A base station provides network access to subscriber
stations and mobile stations, and communicates with other base stations.
The radio frequency and bandwidth of the link between the MAX208M2W Series
and the base station are controlled by the base station. The MAX208M2W Series
follows the base station
’ s configuration.
Authentication
When authenticating a user, the base station uses a third-party RADIUS or
Diameter server known as an AAA (Authentication, Authorization and Accounting)
server to authenticate the mobile or subscriber stations.
The following figure shows a base station using an AAA server to authenticate
mobile station MS , allowing it to access the Internet.
Figure 21 Using an AAA Server
In this figure, the dashed arrow shows the PKM (Privacy Key Management)
secured connection between the mobile station and the base station, and the solid
arrow shows the EAP secured connection between the mobile station, the base
station and the AAA server. See the WiMAX security appendix for more details.