Abstract: This study not only provides the overview of all kind of broadband technologies, both wire-line and wireless, but also compares the two prominent broadband mobile technologies- 3G Mobile Cellular and Mobile WiMAX. It compares technical as well as spectrum aspects. In order to make this research comprehensive, WIMAX is compared with existing 3G/3G+ Cellular technologies like High Speed Packet Access (HSPA) as well as with future technologies like Long Term Evolution/Ultra Mobile Broadband (LTE/UMB) by making some assumptions to get some practical results. This study concludes that, in the wake of bandwidth hunger new applications and services, Mobile WiMAX has a great potential to become main stream technology and it has become both threat and opportunity for Mobile Cellular operators.