Review on Vertical Handover Techniques among Heterogeneous Networks

One of the major design issues in heterogeneous wireless networks is the support of vertical handover. Vertical handover occurs when a mobile terminal switches from one network to another (e.g., from WLAN to CDMA 1xRTT). Seamless handover between different access technologies is a great challenge as it needs to obey different performance of QoS and security constraints. Vertical handover decision (VHD) algorithms are essential components of the architecture of the forthcoming Fourth Generation (4G) heterogeneous wireless networks. These algorithms need to be designed to provide the required Quality of Service (QoS) to a wide range of applications while allowing seamless roaming among a multitude of access network technologies. This paper is about the comprehensive survey of the VHD algorithms designed to satisfy these requirements.