With advent of access technologies such as WiFi and WiMAX, access mechanisms are on the verge of providing continuous access anytime, anywhere and most importantly anyhow. The IEEE 802.16e amendment to the IEEE 802.16 standard adds mobility to the original standard and thus makes WiMAX an attractive solution to provide high bit rate mobile wireless services over a broader range of coverage. However, the last mile in open access networks remains vulnerable to attacks at the physical and MAC layers. This paper provides an overview of the security concerns and proposes a robust new architecture model to help protect against attacks from rogue devices for a true mobile security as wireless devices are becoming increasingly vulnerable mini computers. The drive to provide open access is not limited to cellular technology but extends to other wireless technologies such as Wi-Fi and WiMAX.