WIMax can best be described as "a wireless digital communications system, also known as IEEE 802.16, that is intended for wireless "metropolitan area networks".   WiMAX can provide broadband wireless access (BWA) up to 30 miles (50 km) for fixed stations, and 3 - 10 miles (5 - 15 km) for mobile stations. 

What are the benefits of WiMax?

• More broadband access choices, especially in areas where there are gaps: worldwide urban centers where building access is difficult; in suburban areas where the subscriber is too far from the central office; and in rural and low population density areas where infrastructure is poor.
• WiMax is wireless, no need for telkom lines to get broadband access! - This may not seem like a big reason to consider WiMax, especially if you have an existing ADSL line, but theft of telkom cable is rife and when a cable is removed it can take Telkom weeks to install a new cable. ADSL is not a guaranteed service so Telkom has no commitment to you to restore services as soon as possible, all they can do is promise to get around to it when time and resources permit.