Media Independent Handover for Seamless Mobility in IEEE 802.11 and UMTS based on IEEE 802.21

Multiple types of networks are evolving with different radio technologies (RATs) which are having different capabilities, price and performance ratio. When these networks are collocated with each other and when mobile devices roam around across these networks, a heterogeneous network access is formed. Each mobile device is equipped with multiple interfaces to access all types of networks of heterogeneous system. Multiple interfaces can be included in the mobile device by using separate hardware and software modules. The mobile user always wanted to be Always Best Connected (ABC) as per its requirements and availability in a given scenario. When the mobile user leaves and joins the networks, a handover operation is performed. The Handover operation is used to achieve seamless mobility. Handover operation is of two types, one is in between the same RAT and the other is in between the different RAT. For seamless and smooth handover operations across heterogeneous networks, IEEE has defined a standard named as IEEE 802. 21. This paper presents a novel vertical handover scheme applicable for IEEE 802.11 (WLAN) and Universal Mobile Telecommunication System (UMTS) based on IEEE 802.21. UMTS is a 3GPP (Third Generation Partnership Project) technology, which is being used in cellular networks. WLAN is a LAN technology which supports smaller coverage area than the cellular networks. Vertical handover between these two is needed because they have different RAT.