WiMAX is a new broadband wireless technology capable of deliverying speeds up to and beyond 100Megabits/per second (Mbps) over a wide coverage (up to 30 miles).
There is also a 'Mobile WiMAX' standard for operation over wider ranges, useful with mobile phone operators and often known as a fourth generation (4G) technology.
Full Details:
http://www.ispreview.co.uk/broadband_wireless.php
