This report will provide essential and detailed information regarding the security issues relating to various technologies for example generations of mobile, WLAN, Bluetooth, etc. Security these days is of utmost priority at all levels and because wireless communication forms the focal point for all communications means therefore we decided to investigate several wireless technologies in our report. It is always difficult to achieve total security in any system and wireless communication is prone to different kinds of threats and attack therefore ensuring its security is in the interest of every one related to it. Through the course of this report we will look at the background, the analysis of the security loop holes which present a significant challenge today in these technologies and their impact on those technologies further more we will evaluate the security measures to cover the loop holes in those technologies.