Analysis Of The Vertical Handover In LTE

A key aspect of the 3GPP system architecture evolution is the specification of an evolved packet core that supports multiple access networks.The EPC enables operators to deploy and operate one common packet core network for 3GPP radio accesses(E-UTEAN,UTRAN and GERAN),as well as other wireless and wireline access networks(e.g.,eHRPD,WLAN,WIMAX and DSL/Cable),providing the operator with a common set of services and capabilities across the networks.The evolved 3GPP system is a hybrid mobile network architecture supporting several radio access technologies and several mobility mechanisms. First,we studied the 3GPP and non-3GPP network architecture, including the architecture and key components of this system, then we investigated 3GPP and non-3GPP handover process analysis, including non-optimized handover and optimization switch.Finally, we investigated on how it can support voice call mobility in several deployment scenarios.First, we present the so-called single-radio voice call continuity mechanisms that enable mid-call handover of VoIP calls from E-UTRAN access to the legacy UTRAN/GERAN access.Then we focus on deployment scenarios that do not support voice services on E-UTRAN and present the so-called fallback mechanisms that enable handover from E-UTRAN to UTRAN/GERAN or 1xRTT at the beginning of a voice call.Finally, we address the application layer voice call handover mechanisms enabled by the IP multimedia subsystem.In addition, we studied the design and implementation of LTE/HRPD switching system.Our conclusion is that the next generation of 3GPP systems are highly sophisticated mobile communication systems that support extended voice call mobility mechanisms, capable of addressing all commercial deployment needs.