In this era of technology, next generation wireless networks are very popular that allow users to connect to different radio access technologies such as UTMS, WiMax, GSM, etc. In such heterogeneous environment Vertical Handover is executed thus a user can switch among different radio access networks that makes whole process so complex. Vertical Handover algorithms require many parameters such as interference power, QoS, network conditions, terminal capabilities, monetary cost and so on. Only RSS measurements are not enough in VHO’s case. Consequently, the VHO decision process becomes significantly complex. This paper presents a synopsis of Handover management process and focuses on Vertical Handover decision issues. Furthermore, for assessment of the VHO process, vertical handover index VHOI is …show more content…
Vertical handover is a network node that automatically changes its type of connectivity to access a supporting infrastructure. When a computing device could possibly connect to the Internet via two different network technologies, it is automatically connected to the available network. This switching between two networks is the vertical handover. Vertical handover is usually done to support the node mobility.
A well-equipped laptop may use both wireless LAN (WLAN) and cellular network connection technology to access the internet. WLAN is a reliable technology that, at very low rates, can provide higher bandwidth. A cellular network is not as reliable but generally provides ubiquitous coverage. A cellular network is often costly, and available bandwidth depends on the network traffic. The WLAN is configured by default on the laptop. Nevertheless, upon WLAN failure, the cellular network is available to keep the user connected to the Internet. The shuffling/shifting from one technology to the other is the vertical handover, which maintains a user’s machine connection with the Internet and ensures unremitting