WiMAX is a wireless broadband technology based on Wireless Metropolitan Area Networking (WMAN) standard developed by IEEE 802.16 group. Worldwide interoperability for Microwave Access (WiMAX) is a recent wireless broadband standard that has promised high bandwidth over long-range transmission. The standard specifies the air interface, including the Medium Access Control (MAC) and PHYsical (PHY) layers, of BWA. In this paper, an extended overview of the WiMAX is presented. It looks at the technology behind WiMAX and networks design and deployment factors that impact WiMAX coverage.