Security in the wireless access network gained increasing interest over the last years. Its implementation varies from one access network to another. The current trend in wireless access network is towards implementing mechanisms for mobility management namely handoff process and quality of service control. Consequently, security should be taken into consideration at each handoff process which may occur between different technologies (inter-technology) or within the same (intra-technology). At the same time, security provisioning impact on network performances (e.g. end-to-end delay, throughput) should be controlled. This chapter aims to give a better understanding of security measures and protocols available in two distinct wireless networ...