Reducing re-authentication delays during UMTS-WLAN vertical handovers

Interworking universal mobile telecommunication systems (UMTS) and IEEE 802.11 wireless local area networks (WLANs) introduces new challenges in the design of secured and fast vertical handover (VH) protocols. VH operations must not compromise the security of the network. In addition, VH delays must be minimized to maintain the quality of service of the applications running on the user equipment (UE). Re-authentication is normally required during UMTS-WLAN VH. Existing re-authentication protocols invoked in UMTS-WLAN VH are either inadequately secure or introduces unacceptable delays. This paper proposes couple of re-authentication protocols that reduce re-authentication delays during UMTS-WLAN VHs compared to existing protocols by substantially reducing message signaling. Additionally, they achieve secured key management and mutual authentication between the UE and authentication servers in the 3G home network.